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BACKGROUND OF THE INVENTION
This invention relates to a method of preparation of a dilute standard gas, said gas itself and an apparatus for the performance of said method.
Many difficulties have been encountered in conventional methods for preparation of a dilute standard gases used, for example, in the calibration of standards in gas microanalysis and also for the calibration of automatic, continuous gas analyzers.
Among the difficulties encountered in conventional methods there may be mentioned inevitable errors resulting from unrepresentative sampling of a given gas, unhomogeneous mixing of said gas with a diluent, loss of gas by the absorption thereof onto the surface of receiver vessel and also a change of concentration of gas due to the generation of the target (desired) gas itself or due to the instability of the gas.
Among the many methods which have been hitherto proposed to provide accurate, dilute standard gases, the permeation tube method is considered to be most superior and widely used. The permeation tube consists of a tube of a polymeric substance such as Teflon containing a liquified or a highly compressed gas to be used in the preparation of the standard gas.
Both ends of the permeation tube are sealed. Since the vapor pressure of the gaseous sample in the inside of the tube becomes high, a small amount of the gas is always purged through the wall of the tube. If the temperature of the tube is constant, the amount of purged gas per unit time becomes constant. The permeation tube is then placed in a fresh air flow of a definite flow rate at a constant temperature to provide a dilute gas of definite concentration.
The permeation tube method has advantages such as the fact that it is possible to directly generate a very small amount of gas at a constant rate and moreover it is, of course, possible to determine the absolute rate of gas generation from the permeation tube, merely by measuring the weight loss of the tube.
On the other hand, the permeation method has several disadvantages in practice, although the basic principle of the method is rather simple. The main disadvantages include the necessity to carefully regulate the temperature of the air flow since the rate of generation of gas from the tube changes drastically with a small change of the temperature, a rather long time lag to obtain a gas flow of a constant concentration after the beginning of the flow of air and the need for skill in the preparation of the permeation tube, despite the simplicity of the principle.
SUMMARY OF THE INVENTION
The primary object of the present invention is to provide a method for the preparation of a dilute standard gas free from the above disadvantages encountered in the permeation tube method.
The above objective and others are realized by the present invention as follows:
A solution of a compound which is able to generate a target gas is prepared. The pH of the solution is adjusted by a buffer e.g. solution in order to obtain the target gas at a constant vapor pressure from the solution.
Simultaneously, an air flow is passed through the vapor from the liquid phase of the solution at a constant rate. It is not necessary that an air flow must be passed at "a constant rate" in order to take up the target gas in a desired amount. Thus, various kinds of dilute standard gases can be prepared.
The advantageous features of this method are as follows:
(1) It is possible to generate a dilute standard gas to any desired concentration.
(2) It is possible to continuously produce a standard gas of a desired definite concentration over a long period.
(3) As in the permeation tube method, it is possible to determine the absolute rate of gas generation by measurement of change of the concentration of the gas generation solution.
(4) The reproducibility of a dilute standard gas having a desired concentration is very superior.
(5) The time lag to obtain a standard gas having a desired definite concentration, after the beginning of the flow of gas, is rather short.
(6) The regulation of temperature is not very critical.
(7) No special apparatus is required.
(8) The operation is simple and does not demand skilled operators for its performance.
(9) The present invention can be applied to the preparation of dilute standard gases such as nitrogen oxides, sulfur oxides, hydrogen sulfide, hydrogen cyanide and other inorganic gases as well as formaldehyde and other organic gases.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts a schematic side elevational view of a gas generating bottle used in the method;
FIG. 2 is a diagrammatic depiction of the gas generating apparatus;
FIG. 3 is a graph depicting the relationship between the concentration of hydrogen cyanide gas in the air flow and the temperature of a water bath controlled by a thermostat provided in the gas generating apparatus to control the temperature of gas generation and
FIG. 4 depicts the change of concentration in air (C air ) of hydrogen cyanide gas in an air flow (passing through the vapor phase of the gas generating solution) against time.
DETAILED DESCRIPTION OF THE INVENTION
The method of preparation of dilute standard gas of the present invention will be further explained with reference to the preparation of a dilute standard of gaseous hydrogen cyanide. It is generally considered that, even though it is a standard gas of high concentration, the preparation of hydrogen cyanide gas of a definite concentration is not a simple matter.
EXAMPLE
Apparatus and Reagents
Hydrogen cyanide gas analyzer: a digital pH meter (Type HM-20B manufactured by the Toa Electrotech. Corp.), a selective electrode for cyanide use (Type CN-125 manufactured by the Toa Electrotech. Corp.) and a reference electrode (Type HC-305D manufactured by the Toa Electrotech. Corp.).
Thermostat of aqueous medium type: capable of regulating the temperature between about +5 and 80° C. within an accuracy of ±0.08° C.˜±0.12° C. (Type Thermomeit TH-11 manufactured by the Yamato Scientific Corp.).
Flow meter: a flow meter (100˜1400 ml/min) (Type FT-1/8-4-150 manufactured by the Kusano Scientific Corp.) and an orifice flow meter of the mercury type.
Reagents: potassium cyanide and sodium hydroxide (both reagents used in the following experiments were of a special reagent grade produced by the Kokusan Chem. Corp.).
Buffer solutions:
a solution of pH=7.0
. . this solution is prepared by dissolving 6.80 g of potassium dihydrogenphosphate and 1.19 g of sodium hydroxide into water to obtain 1 l of solution.
a solution of pH=8.9
. . this solution is prepared by dissolving 3.1 g of boric acid, 3.73 g of potassium chloride and 0.85 g of sodium hydroxide into water to obtain 1 l of solution.
a solution of pH=11.0
. . this solution is prepared by dissolving 17.5 g of disodium hydrogen phosphate (Na 2 HPO 4 .12H 2 O) and 0.33 g of sodium hydroxide into water to obtain 1 l of solution.
a solution of pH=11.9
. . this solution is prepared by dissolving 17.9 g of disodium hydrogenphosphate (Na 2 HPO 4 .12H 2 O) and 1.728 g of sodium hydroxide into a water to obtain 1 l of solution.
A ribbon heater or the like is desirably provided.
Experimental Apparatus and Operation
The main numerals and letters employed in FIGS. 1 and 2 are summarized here for convenience.
(1) gas absorbing bottle of 30 ml capacity, (2) gas inlet tube, (3) gas generating liquid, (A) air inlet, (B) layers of air purifying agent, (C) flow meter, (D) manometer, (E) thermometer, (F) thermometer, (G) preheating chamber, (H) gas generating chamber, (I) distilled water for humidity control, (J) gas generating liquid, (K) thermostatically controlled water bath, (L) heater, (M) ribbon heater, (N) gas exit tube, (P) gas collecting means and (Q) agitator.
With reference to FIG. 1, a commercially available gas absorbing bottle (1) of 30 ml capacity of a bottle of the Greenburg Smith type is employed as the gas generating chamber. The surface of gas generating liquid (3) is adjusted so as not to contact the center of the gas introduction tube (2) when the liquid is charged in the bottle. Gas is removed via exit tube (4).
The arrangement of a standard gas generating apparatus is depicted in FIG. 2, wherein a gas generating chamber (H) containing a gas generating liquid (J) consisting of a mixture of a pH buffer solution and a potassium cyanide solution is partially immersed in a water bath (K) which is thermostatically maintained at 40° C. A purified air flow supplied from an inlet (A) and passed through gas purifying layers (B) and is introduced into the gas generating chamber (H) through a preheater chamber (G) and it passes through at a constant rate (in this example, it was 300 ml/min) over the surface of the gas generating solution (J). A gas exit tube (N) which permits removal of the air flow from the gas generating chamber (H) is heated by a ribbon heater (M). Thus, the air flow removed from the gas exit tube (N) by gas collecting means (P) contains the target or object gas in a desired amount and is suitable for use as a dilute standard gas.
The flow rate of the air flow is measured by a flow meter (C) and the observed value is corrected to the standard state using the observed temperature and pressure indicated by a thermometer (E) and a manometer (D), respectively.
The concentration of hydrogen cyanide contained in the obtained standard gas can be determined analytically using a cyanide ion selective electrode after dissolving the cyanide gas contained in the standard gas into an aqueous solution of sodium hydroxide.
In FIG. 2, (I) is distilled water provided in a preheater (G), to be used for humidity control, (L) is a heater, (Q) is an agitator.
Results and Interpretation Thereof
A series of experiments were carried out using aqueous solutions of potassium cyanide whose concentrations were 60, 30, 10 and 5 μg/ml and adjusting the pH of each solution to 7.0, 8.9, 11.0 and 11.9. From those experiments, it was found that the amount of hydrogen cyanide generated from a solution of any concentration of potassium cyanide rapidly decreases when the pH of the solution exceeds 11.0.
The concentration of potassium cyanide in the gas generating solution, C sol (μg/ml) and the concentration of the target gas in the air flow, C air (ppm), exhibit a linear relation if plotted on a log-log paper, that is, the relation can be expressed by the following equation (1),
C.sub.air =k·C.sub.sol.sup.n (1)
wherein, n is the inclination of the said straight line and k is the value of C air when C sol =1. Moreover, such relation between n and k as depicted in Table 1 was found at various pH values when the concentration of potassium cyanide in a gas generating solution was 350 μg/ml and the flow rate of the air flow was 300 ml/min.
TABLE 1______________________________________Examples of n and k in Eq. (1) (HCN)pH n k______________________________________7.0 0.98 0.488.9 0.98 0.4411.0 0.96 0.05811.9 0.90 0.014______________________________________
The relation between the temperature of gas generating liquid and C air is depicted in FIG. 3, wherein the concentration of potassium cyanide was 350 μg/ml, the pH value was 11.9 and the flow rate of air was 300 ml/min. The relationship depicted in FIG. 3 is nothing but a type of vapor pressure curve from this figure, it can be understood that the increase of C air with the increase of the temperature is rather gradual, if compared with such relation in the permeation tube method.
The change of C air value with respect to time is shown in FIG. 4, wherein three different concentrations of C sol were employed, i.e. 148, 150 and 194 μg/ml. The temperature, flow rate of air and pH were at constant values, e.g. 40° C., 300 ml/min and 11.9, respectively.
In the figure, it can be seen that, in the initial stage of about 100 minutes, the change of the concentration C air was within the range of experimental error for the measurement of cyanide ion concentration, using the ion selective electrode and after 100 minutes, a small increase of the temperature was confirmed.
The fact that the concentration C air slightly increases with respect to time may be due to a natural increase in the concentration C sol .
From these observations, the following can be presumed.
(1) There is hardly any decrease of the concentration of potassium cyanide in the gas generating liquid during the use of said liquid.
(2) The agitation of the gas generating liquid due to convection occurs.
(3) Under the experimental conditions, the concentration of the gas generating liquid due to the evaporation of water therefrom occurs more rapidly than the dilution of the liquid due to the escape of hydrogen cyanide therefrom.
Furthermore, methods for the production of standard gases other than hydrogen cyanide were successfully carried out. In this regard, the results of two experiments to produce dilute standard gases, nitrogen oxide (NOx) and sulfur dioxide (SO 2 ), which gases are very detrimental to environmental quality, are shown in Table 2.
TABLE 2______________________________________Data for Generation of NO.sub.x and SO.sub.2Type of Rate of Temper-gas gen- Gas generat- Air Flow atureerated ing Compound ml/min °C. pH n k______________________________________Nox NaNO.sub.2 910 25.0 5.0 0.73 0.015SO.sub.2 NaHSO.sub.3 300 25.0 4.3 -- --______________________________________
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Dilute standard gases are prepared by utilizing a buffered solution of a compound capable of generating a desired gas. The pH of the solution adjusted so as to provide a solution with a desired specific vapor pressure of said gas and said gas is absorbed by a flow of air passed through the vapor phase above the solution. An apparatus for the performance of said process is also provided.
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BACKGROUND OF THE INVENTION
Tee shirts with images thereon may be purchased at stores all over the world. The customer often selects a decal from a preexisting inventory of decals and the shop owner then applies the selected decal to the tee shirt, typically with a large, commercial hot press iron. During this process, the original decal is used only once during the transfer process since it is physically applied to the tee shirt. There is no known process for recovering and reusing the original decal, and there exists no technique for personalizing a tee shirt without the assistance of a personal computer or going through the costly process of reproducing onto a commercial offset printer.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the invention to utilize a process where the original artwork is preserved and protected, thereby reducing costs to the merchant selling the tee shirt.
Another object of the invention is to provide the merchant with a process where the merchant would not run out of inventory, since he will never run out of the original design. Thus, the merchant will not lose business due to lack of inventory.
Further, it is an object of the invention to personalize artwork that may be transferred to a tee shirt or other receptor element without the use of a computer literate employee.
As a result of the present invention, no personal computers are necessary for personalizing the tee shirt. This reduces costs for store management by avoiding the need for training employees on the use of computers. Thus, as a result of the invention, the merchant will save costs with respect to the purchase of computer hardware and software, and the maintenance thereof.
Accordingly, the present invention relates to a method of reusing artwork used in tee shirt transfers, which comprises the steps of: (step i) selecting pre-existing artwork (i.e. decals; text) or creating original artwork (i.e. paintings, drawings, text or pictures), (step ii) inserting said selected pre-existing artwork or created original artwork into a folder having a first member and a second member wherein at least one of the first or second members is clear and transparent (i.e. plastic, glass) or inserting said selected pre-existing artwork or created original artwork beneath a clear, transparent sheet (i.e. plastic, glass), said clear folder or clear sheet having decorative borders or artwork thereon that will be visible on the final image to be transferred, (step iii) reproducing said selected pre-existing art-work or created original artwork and said clear folder or clear sheet onto a transfer material (i.e. reproducing by copying with the first member of the folder face down on the copier onto a transfer material, or by copying with the sheet face down on the copier and the artwork on top of the sheet onto a transfer material; or reproducing by scanning the image into a computer and outputting to a printer onto a transfer material), and (step iv) transferring said selected art-work or created artwork onto a receptor element. The artwork in the folder or above the sheet as oriented in the copier may then be recovered for reuse.
The present invention further relates to a method of creating personalized, transferable artwork, which comprises the steps of: (step i) selecting pre-existing artwork (i.e. decals; text) or creating original artwork (i.e. paintings, drawings, text or pictures), inserting said pre-existing artwork or created original artwork into a folder having a first member and a second member wherein at least one of the first or second members is clear and transparent (i.e. plastic, glass), or inserting said pre-existing artwork or created original artwork beneath a clear, transparent sheet (i.e. plastic, glass), said clear folder or clear sheet having no printing or form-work thereon that will be visible on the final image to be transferred and being capable of being written upon, hand-writing onto the clear folder or clear sheet, thereby personalizing said clear folder or clear sheet, (step ii) reproducing said selected pre-existing art-work or created original artwork and said clear folder or clear sheet having handwriting thereon onto a transfer material (i.e. reproducing by copying with the first member of the folder face down on the copier onto a transfer material, or by copying with the sheet face down on the copier and the artwork on top of the sheet onto a transfer material; or reproducing by scanning the image into a computer and outputting to a printer onto a transfer by scanning into a computer and outputting to a printer onto a transfer material), and (step iii) transferring said pre-existing art-work or created original artwork together with said handwriting onto a receptor element. The artwork in the folder or above the sheet as placed on top of the copier may then be recovered and the folder or sheet may be erased for reuse later. In (step i), the order of the substeps is not important. For instance, the desired message can be written onto the folder or sheet prior to selection of or creation of the artwork.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from the detailed description given hereinbelow, and the accompanying FIGURE which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:
FIG. 1 shows a folder of the invention.
DETAILED DESCRIPTION OF THE INVENTION
In one embodiment of the invention, a plurality of pre-existing pieces of artwork are each protected by a folder of clear, protective material so that the "master" piece of artwork may be used over and over again. This first embodiment of the invention does not require any training of the user concerning the use of a computer, since original "masters" of the pre-existing artwork can be sealed within suitable folders (i.e. plastic or glass) or inserted beneath a protective sheet (i.e. plastic or glass) for reuse time and time again.
In another embodiment of the invention, the "master" pieces of artwork are not limited to a finite number which are presealed for protection. Virtually any image can be scanned into a computer by commercially available scanners or images may be selected or downloaded from any number of computer databases that are available, including from the internet. In fact, artwork may be created for the first time on a home computer and used in the invention. In any event, the artwork may be locally printed from any database to obtain the created original artwork to be transferred, and the original image may be maintained on the computer database for reuse over and over again, or for the creation of several hardcopy "masters". The original "master" image is not electronically manipulated. Briefly, the desired image (i.e. artwork) is printed from the computer, the personalized handwritten message is then placed directly onto the hardcopy print-out, and the composite artwork/handwriting is scanned back into the computer for printing onto transfer paper. Or, the personalized message alone may be scanned into a computer file and merged with the artwork to create a composite image file containing artwork and handwritten message, which is then outputted to a printer containing transfer paper, or printed onto a sheet of paper and copied onto transfer paper.
Accordingly, once artwork is selected from a computer database or scanned into a computer, it may be printed onto a suitable support, such as plain paper. The user may then personalize the desired artwork to be transferred by writing on the desired artwork or by writing on the protective folder or sheet (i.e. if the print-out is a "master") and copying the artwork and handwritten personal message onto transfer paper. Of course, after writing onto the artwork the image may then be scanned back into the computer where the handwritten personalized message alone or composite artwork/message may be reversed and reproduced onto Cycolor transfer paper, photographic transfer paper, etc. by methods known in the art. The same reversing of the handwritten message (and optionally artwork) is necessary within the copier if a copy machine is used. This reversing of the handwritten message allows the message to be correctly printed so that it can be read in the conventional manner (i.e. left to right for English) upon transfer onto the desired receptor element. That is, software may be provided within the computer and the copier which permits the writing (and optionally artwork) to be reversed. The reversed writing would then be transferred to the printer and printed in reverse form onto the transfer sheet. Upon transfer, the personalized hand-written message would be properly oriented. The problem and solution of reversing text in transfers per se is known in the art, as is described, for example, in U.S. Pat. Nos. 4,773,953, 4,980,224 and 4,966,815.
In the case of copiers which are not capable of reversing the reproduction, the sheet having writing thereon may be overturned so that the face of the sheet that does not contain the writing (i.e. the unwritten backside of the sheet) is placed in direct contact with the supporting surface for documents to be copied (i.e. glass or plastic) and then copied so as to create a reverse image on the transfer material. Similarly, the folder containing the writing may be reverse folded so that the unwritten backside face of the member of the folder that contains the writing is placed in direct contact with the glass and then copied so as to create a reverse image on the transfer material. This procedure allows proper orientation on the transfer sheet and ultimately on the receptor element using copiers which are not capable of reversing the reproduction.
The folder, which holds the artwork, may have at least one clear, transparent member and may comprise any suitable material for protecting the artwork. This material is preferably capable of receiving ink or another similar writing fluid. The folder is preferably absorbent to receive ink or similar writing fluid. However, nonabsorbent coatings may be written on with such writing utensils as erasable markers, wax crayons, or oil pastel crayons. Similarly, the clear, transparent sheet, which protects the artwork, may be made of any suitable material, including materials preferably capable of receiving ink or another similar writing fluid. Preferably, the transparent member of the folder or sheet is flexible and composed of cellophane, cellulose acetate, mylar film, plastic (i.e. polyethylene terephthalate, polycarbonate, acetylcellulose, cellulose ester, polyvinylacetate, polystyrene, polypropylene, polyvinyl chloride, nylon, polyethylene) or the like and is most preferably of a character adapted to receive and retain ink or similar fluid. Most preferably, the folder or sheet is flexible, and the ink or fluid is erasable so that the folder or sheet may also be reused.
The clear, transparent folder or sheet preferably does not have printed windows or blocks for data entry or any other printed indicia. The transparent material should allow clear, non-interfering viewing of the artwork beneath it. In the case of a folder, no indicia is placed on the second or backing member, since it is desired to copy only the selected artwork and the personalized hand-written message onto the transfer paper.
The second member in the folder (i.e. backing for the folder) may be of the same material as the first member, or may be of any suitable backing material such as a white sheet material (i.e. white bond paper) or a colored sheet material (i.e. colored paper).
Preferably, no indicia should be located on the first or second member of the folder, or on the transparent sheet, since such indicia should not be copied onto the transfer material along with the artwork. If indicia is present on the folder or transparent sheet, it should preferably be of such a character that it will not be copied onto the transfer material. The material of the folder or transparent sheet is preferably selected so as to be sturdy enough to be reused many times during reproduction (i.e. copying) and during the handwriting process of the invention.
In another embodiment of the present invention, the folder or sheet is not entirely clear or transparent. For instance, the artwork may be inserted into a folder having a first and second member wherein at least a portion of the first member is of sufficient size for receiving a written or drawn message thereon, or inserted above (i.e. as oriented on a copying machine) at least a portion of a sheet which is of sufficient size for receiving a written or drawn message thereon, said folder or sheet is capable of being written upon and retaining writing so that the writing is visible and present only on the folder or sheet. In this way, the folder or sheet which is to be written upon may have borders (i.e. decorative) or additional artwork thereon.
The size of the transparent member of the folder or sheet is not critical. The purpose of these elements is to protect the selected artwork from being written directly upon. Therefore, the folder or sheet need only be large enough to cover the area which is being written upon. Since the folder and artwork combination or transparent sheet and artwork combination is stationary within a copier, the design of the folder or transparent cover sheet is not critical. That is, there is no need for the folder to be bigger, the same size or smaller than the artwork. Since the folder and artwork combination or sheet and artwork combination does not have to travel through a copy machine, the size of the transparent material is not critical. Whatever size that is convenient for the user may be selected, so long as the desired handwriting is positioned in the targeted location on the artwork so that the combined image is transferred onto the transfer material, which is then transferred to the receptor element. However, the folder is preferably larger than the artwork and the artwork is most preferably securely sealed in the folder.
The folder may be attached on one, two, three or all sides by any fastening means (i.e. adhesive, crimps in sides of folder, mechanical fasteners, and the like). The folder is merely a convenient means for holding the selected artwork in the copier. However, a clear, transparent sheet is sufficient since it is not necessary that the artwork is held in the copier in any special manner. The folder and the sheet are convenient means for receiving the handwriting, when applied, and for protecting the artwork for reuse.
The sheet that contains the handwriting may simply be placed in front of the artwork in a copier machine so that the writing is in the desired position on the artwork. In this way, upon copying, the transfer material will contain both artwork and personal message "written" thereon in the desired position without the assistance of a computer. In order to make sure that the handwriting is in the desired location, the folder or sheet may be divided (i.e. into quadrants) so that the artwork and personalized handwriting are placed in the desired location.
It is unnecessary to utilize adhesive between the transparent member of the folder or sheet and the artwork. Alternatively, each original piece of artwork may either be permanently or semipermanently positioned in its own folder via adhesive. The folder is preferably one that is capable of receiving a fluid, such as ink. This fluid is preferably erasable. In this way, each original piece of artwork is protected and may be used time and time again.
In the case where both members of the folder are not clear and transparent, the folder may be a document carrier comprising a planar paper back member 10, preferably rectangular and flexible, covered by a liftable transparent rectangular sheet 8. In order to use the folder, sheet 8 is raised, and the artwork 4 is inserted with the rear surface thereof atop back member 10. Depending upon their size with relation to back member 10, several pieces of artwork may be inserted thereupon simultaneously. Transparent sheet 8 is then dropped over artwork 4 which is thus held between sheet 8 and member 10, and the document carrier/folder is ready for copying onto transfer paper.
The transparent folder or sheet and art-work combination is not a pressure sensitive system such that when writing is applied onto the surface of the folder or sheet, said writing is transferred to the artwork beneath the sheet. On the contrary, the present invention preserves the artwork positioned within the folder or above the sheet when positioned in the copier so that the artwork may be reused. Moreover, in the present invention, the artwork placed within the folder or beneath the sheet in (step i) is not pressure sensitive.
In the present invention, several pieces of artwork may be placed within the folder or above the cover sheet when positioned in the copier, preferably in such a way so that the artwork does not overlap. In a preferred embodiment of the invention, only a single piece of artwork, such as a decal, is placed within the transparent folder or above the transparent cover sheet when positioned in the copier.
Artwork as defined herein is broadly defined in the conventional sense and includes illustrative and decorative elements of printed materials. However, in the present invention, artwork can also include written text, such as jokes or comments, or advertisements, as is frequently seen on tee shirts. Preferably, artwork of the invention is not a plurality of stacked paper sheets separably joined as a set having similar image areas and wherein each sheet has a distinct coding around a portion of its outside edge for facilitating routing, transmission to, storage in, and retrieval of each sheet from a predetermined location. The invention preferably comprises only a single transparent folder or cover sheet and not a plurality thereof.
The transparent protective sheet does not have an image receiving layer coated onto the back surface thereof.
Transfer materials per se are well known in the art, and any suitable transfer material may be used in the invention. For example Canon creative products T-Shirt Transfers TR-101 may be used. Other suitable transfer materials include those described in U.S. Pat. Nos. 4,773,953 and 4,980,224 including a transfer sheet known as "TRANSEEZE" manufactured by Kimberly-Clark Corporation or any other commercially available transfer sheet which has a substrate with a coating which is transferable to a receptor sheet upon the application of heat or pressure to the back of the substrate, and that is coated with Singapore Dammar Resin. The image-receptive heat transfer papers of U.S. Pat. Nos. 5,501,902, 5,271,990, and 5,242,739 may also be used. These papers generally have at least one film layer comprised of a thermoplastic polymer on a support. Also, personalized messages and images may be reproduced onto Cycolor transfer materials as disclosed U.S. Pat. Nos. 5,139,917 and 5,236,801, or onto silver halide transfer materials as disclosed in applications U.S. Ser. Nos. 08/659,700 now U.S. Pat. No. 5,620,598 and 08/479,409,now abandoned. Suitable transfer materials may comprise (i) any known suitable support in the field of transfer materials (i.e. paper), and (ii) coated on the support a release material that is capable of receiving an image thereon (i.e. via photocopying) such as Singapore Dammar resin, Batavia Dammar resin, accroide (yucca) resin, East India resins, Kauri resins, Manila resins, pontianak, and acrylics. Preferably, the transfer paper is capable of receiving an image during copying in a copy machine.
As discussed above, U.S. Pat. No. 5,139,917 discloses a Cycolor transfer material. Such a material comprises a support, a transfer coating and a layer of microcapsules on the transfer coating.
As discussed above, U.S. Pat. No. 5,139,917 discloses a Cycolor transfer material. Such a material comprises a support, a transfer coating and a layer of microcapsules on the transfer coating.
Methods of transferring the image to the receptor elements are also disclosed in the above-mentioned patents. That is, the transfer materials per se utilized in the present invention are known in the art, as are the methods for transferring the images to the receptor element.
The receptor element may be any desired receiver, such as textile, leather, ceramic, wool, glass, or plastic. Preferably, the receptor element is a shirt, tee shirt or the like.
The invention is applicable to Cycolor transfer technology as discussed above. Thus, the personalized message may be scanned into a computer and printed onto Cycolor transfer paper along with the desired artwork. The most recent version of a Cycolor printer was exhibited in November, 1996, at the COMDEX trade show in Las Vegas, Nev.
The invention is also applicable for use on transfer paper utilized in Thermal Wax Ribbon printing technology. Thus, the transfer paper intended for use for Thermal Wax Ribbons may be inserted into the copier and used as the transfer paper of the claimed process. Alternatively, the artwork that has been personalized may be scanned into a computer and printed out onto a transfer material for use with a thermal wax ribbon printer, such as the Seiko 5401 sheet fed printer. Other commercially available copiers or printers include Sharp CX 5000 model color copier and Toshiba 5400 model. Panasonic, Fargo, Cal Comp and Mitsubishi also manufacture thermal ribbon printers and/or copiers.
The invention is also applicable to transfer paper currently utilized in laser printing. The most popular models and the ones typically used for fabric transfers are Canon Laser copiers 500, 600, 700 and 800 models.
The invention is further applicable to transfer paper currently utilized in ink jet printing. For instance, CANON has a well known Bubble Jet line of transfer products that may be utilized in their printers. Other manufacturers of Ink Jet copiers and/or printers include Hewlett-Packard, Epson, Xerox, Lexmark, Mannesman Tally and Hitachi.
The image together with the handwriting may be copied directly onto these transfer papers via a conventional copier, or first scanned into a personal computer and printed onto any desired transfer paper in the desired printer.
The following example is provided for a further understanding of the invention, however, the invention is not to be construed as being limited thereto.
EXAMPLE
A decal showing a picture of the Golden Gate Bridge is inserted into a clear, transparent, flexible, plastic folder so that the image is showing through a first face of the folder and the back of the decal is on the second face of the folder. A person than takes a pen containing erasable ink and writes on the first face of the folder showing the Golden Gate Bridge the following message: "I Had a Great Time in San Francisco|". The first face of the folder containing the writing and showing the image is placed into a copy machine in a position such that the first face showing the image and writing will be copied. The first face is copied onto an 8.5×11 inch sheet of Canon creative products T-Shirt Transfers TR-101, and separately onto transfer papers from each of U.S. Pat. Nos. 5,501,902, 5,271,990, 5,242,739. The image is then transferred to a tee shirt with a hand held iron sold for use in a consumers' home in the manner described in each of these patents. For example, in the case of Canon TR-101, a household iron is preheated on its highest setting for about 8 minutes. A pillowcase is folded in half and placed on a formica surface. A light colored cotton T-shirt is placed on the pillowcase with the transfer, printed side down, placed onto the garment. The iron is then pushed along the back side of the transfer material, thereby transferring the image to the T-shirt.
The message on the front of the folder is erased (i.e. with water or with a solution of detergent and water or with a household cleaner), and the decal is available for reuse.
The contents of each of the above-mentioned U.S. patents are herein incorporated by reference.
The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the present invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.
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The present invention relates to a method of creating personalized, transferable artwork, which comprises the steps of selecting artwork or preselected images, inserting said artwork or preselected images into a clear folder or beneath a clear sheet, said clear folder or clear sheet having no printing or form-work thereon and being capable of being written upon, handwriting onto the clear folder or clear sheet, thereby personalizing said clear folder or clear sheet, copying said art-work or preselected images and said clear folder or clear sheet having handwriting thereon onto a transfer material, and transferring said art-work or preselected images together with said handwriting onto a receptor element, thereby preserving the original artwork for reuse. The invention demonstrates the only way personalization, such as handwriting, can be transferred onto a receptor element, such as a shirt, in correct order using equipment without an electronic reverse imaging capability.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a novel cephalosporin derivative, a salt thereof, a process for the manufacture of same and a pharmaceutical agent comprising same.
2. Related Arts
A study on cephalosporins has been started from a separation of several antibiotics from a culture solution for Cephalosporium acremonium, which were given a name to Cephalosporin P 1 to P 5 and N, respectively. Thereafter, Cephalosporin C has been isolated from a crude Cephalosporin N.
This Cephalosporin C has a wide antibacterial spectrum to prevent the growth of Gram-positive and negative pathogens, but shows a drawback of a relatively low antibacterial power.
Therefore, various derivatives of the Cephalosporin C have been developped, in which acetoxymethyl radical in 3-position is substituted with another radical or D-α-aminoadipic acid radical bonded to amino radical in 7-position is substituted with another acid radical. As examplar compounds among the derivatives, there are Cephaloridine namely 7-(2-thienyl)acetamido-3-pyridin-1-yl-methyl-3-cephem-4-carboxylate (U.S. Pat. No. 3,449,338), Cephotaxim namely sodium 7-[2-(2-aminothiazol-4-yl)-2-methoxyiminoacetamido]-3-acetoxymethyl-3-cephem-4-carboxylate (U.S. Pat. No. 4,152,432) and the like.
Each of the Cephalosporin C derivatives has the antibacterial spectrum wider than that of penicillins, is effective also to infectious diseases due to Gram-negative pathogens, can be dosed to patients with a penicillin hyperergy due to its low cross allergie to penicillins, and show a relatively low crossed tolerance to penicillins. Therfore, some of those inclusive of said Cephaloridine have already hold a remarkable position in crinical view points.
In order to further develop antibiotical therapy by cephalosporin compounds, however, those having more wide antibacterial spectrum and showing more high activity to fast bacterias and more particularly to Gram-negative pathogens have highly been demanded.
SUMMARY OF THE INVENTION
A principal object of the invention is to provide novel cephalosporin derivatives having a wide antibacterial spectrum to make its applicable infectious diseases wider, a high activity to show a high antibacterial power, and a low toxicity to provide a great safety in its use.
Another object of the invention lies in providing a process for the manufacture of such excellent cephalosporin derivatives.
A further object of the invention is to provide an agent for curing infectious diseases, which comprises at least one of the derivatives and salts thereof, as an effective component.
As apparently known, an antibacterial power of each cephalosporin derivative, when the β-lactam ring in its structural skelton be opened or broken, similar to the case in penicillins.
Therefore, the inventors have carefully studied with paying their possible efforts to finally find out novel cephalosporin derivatives with pyridinium methyl radical in its 3-position, which show a relatively high stability to β-lactamase and have a relatively wide antibacterial spectrum.
The cephalosporin derivatives according to the invention are shown by the formula of ##STR3## wherein R is an organic residue known on β-lactam antibiotics and Q is a radical of ##STR4## dotted-line means a possible double bond, R 1 is hydrogen or mono-valent substituent, R 2 , R 3 and R 4 are mono-valent substituent, respectively.
As the organic residue R, followings may be listed as typical ones. ##STR5##
In case of that the above radicals have an imino ether bond, those having syn arrangement are preferable.
As the mono-valent substituent for R 1 in Q at 3-position of the cephalosporin derivatives according to the invention, following may be listed. Halogen atoms such as F, Cl, Br and the like; alkyl group such as methyl, ethyl, propyl and the like; alkenyl group such as vinyl, allyl and the like; alkinyl group; aromatic group such as phenyl, pyridyl and the like; trifluoromethyl radical; cyano radical; cyanoalkyl group such as cyanomethyl, cyanoethyl and the like; halogenoalkyl group such as chloromethyl, chloroethyl and the like; hydroxy radical; hydroxyalkylgroup such as hydroxymethyl, hydroxyethyl and the like; alkoxy group such as methoxy, ethoxy and the like; alkoxyalkyl group such as methoxymethyl, methoxyethyl and the like; thiol group; alkylthio group such as methylthio, ethylthio and the like; sulfen group; sulfino group; alkylsulfinylalkyl group such as methylsulfinylmethyl, methylsulfinylethyl and the like; alkylsulfonylalkyl group such as methylsulfonylmethyl, methylsulfonylethyl and the like; sulfone group; sulfoalkyl group such as sulfomethyl, sulfoethyl and the like; carboxyl radical; carboxyalkyl group such as carboxymethyl, carboxyethyl and the like; alkoxycarbonyl group such as methoxycarbonyl, ethoxycarbonyl and the like; alkoxycarbonylalkyl group such as methoxycarbonylmethyl, methoxycarbonylethyl and the like; carbamoyl radical; alkylcarbamoyl group such as methylcarbamoyl, ethylcarbamoyl and the like; hydroxycarbamoyl radical; hydroxycarbamoylalkyl group such as hydroxycarbamoylmethyl, hydroxycarbamoylethyl and the like; carbamoylalkyl group such as carbamoylmethyl, carbamoylethyl and the like; dialkylcarbamoyl group such as dimethylcarbamoyl, diethylcarbamoyl and the like; dialkylcarbamoylalkyl group such as dimethylcarbamoylmethyl, dimethylcarbamoylethyl and the like; hydroxyalkylcarbamoyl group such as hydroxymethylcarbamoyl, hydroxyethylcarbamoyl and the like; hydroxyalkylcarbamoylalkyl group such as hydroxymethylcarbamoylmethyl, hydroxymethylcarbamoylethyl and the like; amino radical; alkylamino group such as methylamino, ethylamino and the like; dialkylamino group such as dimethylamino, diethylamino and the like; aminoalkyl group such as aminomethyl, aminoethyl and the like; alkylaminoalkyl group such as methylaminomethyl, methylamino-ethyl and the like; dialkylaminoalkyl group such as dimethylaminomethyl, dimethylaminoethyl and the like; hydroxyiminoalkyl group such as hydroxyiminomethyl, hydroxyiminoethyl and the like; alkoxyiminoalkyl group such as methoxyiminomethyl, methoxyiminoethyl and the like; and aminocarboxyalkyl group such as aminocarboxyethyl, aminocarboxypropyl and the like. These substituents may be bonded in 2, 3 or 4-position of the pyridine ring.
As the mono-valent substituent for R 2 , R 3 and R 4 in Q, followings may be listed as typical ones. A straight-chainalkyl group such as methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-decyl and the like; side-chain alkyl group such as isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl and the like; cycloalkyl group such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl and the like; alkoxy group such as methoxy, ethoxy, 2-methoxyethoxy and the like; phenyl radical; substituted phenyl group such as p-chlorophenyl, p-bromophenyl, p-methylphenyl, p-methoxyphenyl and the like; alkylcarbonyloxy group such as acetoxy, propionyloxy and the like; and trialkylsilyloxy group such as trimethylsilyloxy, triethylsilyloxy and the like. The radical of ##STR6## may be bonded in 2, 3 or 4-position of the pyridine ring.
Among the cephalosporin derivatives according to the invention, basic compounds, for instance those having amino substituted heterocyclic ring in 7-position side-chain or having amino substituted pyridiniummethyl radical in 3-position side-chain may form acid addition salts. As acids for forming the salts, inorganic acids such as hydrochloric acid, hydrobromic acid, sulfuric acid, phosphoric acid and the like; and organic acids such as methanesulfonic acid, benzenesulfonic acid, toluenesulfonic acid, fumaric acid, maleic acid and the like may be listed.
While, acidic compounds, for instance those having carboxyl radical or sulfonic acid residue in 7-position side-chain, or having carboxyl substituted pyridiniummethyl radical in 3-position side-chain may form base addition salts. As such salts, metallic salts such as alkali metal salts (sodium salt, potassium salt and the like), alkaline earth metal salts (calsium salt, magnesium salt and the like) and so on; ammonium salts and organic base salts such as trimethylammonium salts, triethylammonium salts, pyridinium salts, picolinium salts, dicyclohexylammonium salts and the like may be listed.
According to the process of the invention, the cephalosporin derivatives shown by Formula I and salts thereof can be manufactured by reacting a 7-acylamino-3-acetoxymethyl cephalosporin represented by the formula ##STR7## wherein R' is an organic residue known on β-lactam antibiotics, which residue may be protected, and A is a carboxyl protecting radical,
with a halogenated trialkylsilyl, reacting the resulting 7-acylamino-3-halomethyl cephalosporin represented by the formula ##STR8## wherein R' and A have the meanings as referred to, and X is a halogen atom,
with a pyridine derivative represented by the formula ##STR9## wherein R 1a is hydrogen or a possibly protected mono-valent substituent, and R 2a , R 3a and R 4a are a possibly protected mono-valent substituent, respectively,
removing a possible protecting radical or radicals, and if necessary, converting the resulting compound into the salt.
As the protecting radical for the organic radical R' in 7-position, trityl, alkoxycarbonyl, allylalkoxycarbonyl and the like may be listed. As the carboxyl protecting radical A in 4-position, ester functional radicals which can easily be removed, for instance alkyl group and substituted alkyl group (t-butyl, 2,2,2-trihaloethyl and the like), benzyl and substituted benzyl group (p-methoxybenzyl, p-nitrobenzyl and the like), trialkylsilyl and the like may be listed. It is possible to make the both protecting radicals in 4 and 7-positions common, whereby an introduction and removal of same can be made easy. In this sense, it is quite preferable to employ trialkylsilyl group, for instance trimethylsilyl radical or the like as the common protecting radical.
In case of starting from 7-acylamino-3-acetoxymethyl-3-cephem-4-carboxylic acid to introduce trimethylsilyl radical, as the protecting one in each of 4 and 7-positions, this protecting operation can be done by suspending the starting carboxylic acid in a halogenated hydrocarbon solvent such as methylene chloride, chloroform, chloroethane and the like, or another inert organic solvent such as acetonitrile, propylnitrile or the like, adding a widely employed silylating agent such as mono or bis-trimethylsilylacetamide and more preferably N-methyl-N-trimethylsilyltrifluoroacetamide, and stirring the suspension at room temperature.
As the halogenated trialkylsilyl for converting the compound II into the compound III, trimethylsilyl iodide may be employed. This agent is used in amount of at least 1 equivalent and more preferably of 2 to 3 equivalents. This halogenating reaction also proceeds by stirring the reactants at room temperature.
It is not always necessary to isolate the resulting compound III of 3-halomethyl derivative. Therefore, it is sufficient only by concentrating the reaction mixture, removing the volatile substance, for instance the solvent, dissolving a residue in an inert solvent such as acetonitrile, and then adding tetrahydrofuran to decompose possible unreacted halogenating agent. The resulting solution containing the 3-halomethyl derivative is mixed with a solution containing the pyridine derivative (compound IV), which solution is prepared by dissolving the derivative in a suitable solvent such as acetonitrile (if the derivative has carboxyl, amino or the like radical in its pyridine skelton, it is preferable to protect the radical through a preliminary treatment using a silylating agent such as bis-trimethylsilyltrifluoroacetamide and the like). The reaction between the 3-halomethyl derivative (compound III) and pyridine derivative (compound IV) occurrs easily and proceeds only by stirring the mixture at room temperature. After completion of the reaction, water is added to the reaction mixture, which causes a removal of the protecting radical and precipitation of the desired compound which is to be obtained through a filtration. In general, the resulting compound is a crude one and thus refined. The refining may be carried out by a column chromatography.
According to a modified process of the invention, which is somewhat different from the operation as above, the cephalosporin derivatives shown by Formula I and salts thereof can be manufactured by reacting a compound represented by the formula ##STR10## wherein R' has the meaning as referred to, A' is hydrogen or a carboxyl protecting radical, and B is a radical which can be substituted with a nucleophile,
with a pyridine derivative represented by the formula ##STR11## wherein R 1a , R 2a , R 3a and R 4a have the meanings as referred to,
removing a possible protecting radical or radicals, and if necessary, converting the resulting compound into the salt.
As the substituent B in 3-position of the starting material (compound V), acetoxy, propionyloxy, chloroacetoxy, acetylacetoxy and the like acyloxy group, halogen atom, carbamoyloxy and the like may be listed, but acetoxy is most preferable. While, as the carboxyl protecting radical A in 4-position, metal atoms such as sodium, potassium and the like; and easily removable ester functional radicals such as alkyl group, substituted alkyl group, benzyl, substituted benzyl and the like may be listed.
The reaction between the compounds IV and V can be carried out in a solvent and more particularly in water or a mixture of water and an organic solvent which easily mix with water, for instance acetone, dioxane, acetonitrile, dimethylformamide, dimethylsulfoxide, ethanol or the like. In general, the temperature of 10° to 100° C. is preferable for the reaction, but 20° to 80° C. is more preferable.
The pyridine derivative shown by Formula IV may be used in an amount of 1 to 10 equivalents and more preferably 3 to 5 equivalents and in order to accerate the reaction, a neutral salt such as potassium iodide, sodium iodide, potassium thiocyanate, sodium thiocyanate or the like may be added. In this case, it is preferable to carry out the reaction near neutral point and more preferably at pH range of 5 to 8 and therefor, sodium hydrogen carbonate may be added.
One of the starting materials, namely 7-acylaminocephalosporanic acid shown by Formaula II or V is available from the market and otherwise, it may be synthesized in a manner known per se. For instance, 3-[(acetyloxy)methyl]-7-[[(2-amino-4-thiazolyl)(methoxyimino)acetyl]amino]-8-oxo-5-thia-1-azabicyclo[4,2,0]oct-2-ene-2-carboxylic acid can be prepared, in accordance with the manner as disclosed in U.S. Pat. No. 4,152,432. The pyridine derivative shown by Formula IV as the other starting material may also be synthesized in a manner known per se. For instance, 3-trimethylsilylpyridine can be synthesized, in accordance with the manner as disclosed by F. Effenberger "Justus Liebigs Ann. Chem.", Page 842 (1979).
The cephalosporin derivatives and salts thereof according to the invention show a relatively wide antibacterial spectrum, inhibit the growth of various bacterias inclusive of etiological Gram-positive and negative pathogens, and show a relatively high antibacterial power. The LD 50 of the compounds is higher than 1 g/kg on the mouse and thus its toxicity is quite low to ensure the safety in use.
The process according to the invention for preparing such compounds shows advantages of that the reaction between the raw materials of 7-acylaminocephalosporanic acid and the pyridine derivative can be carried out under the mild condition of mere stirring at room temperature, to make operation and other treatments easy.
DOSING FORM AND AMOUNT
In case of preparing an infectious curing agent, effective component of which is one of the cephalosporin derivatives and salts according to the invention, there is no limitation in its medicine form and thus it may be made into one for oral or non-oral route, namely capsules, tablets, suger-coated tablets, ointments, suppositories and the like solid or semi-solid form, or solution, suspension, emulsion or the like liquid form. If necessary, conventional addives such as an auxiliary, stabilizer, wetting agent, emulsifier, buffer and the like may be composed.
A dosing amount of the compound for human depends on kind of the compound to be selected, condition of illness, age of a patient, form of the medicine and other variable factors but in case for an adult, 100 to 2000 mg/day is preferable.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The invention will now be further explained with reference to Examples for preparing the compounds, Examples for testing pharmacological effects of the compounds and Examples for preparing pharmacological agents.
EXAMPLE 1
[6R-[6α,7β(Z)]]-1-[7-[[(2-Amino-4-thiazolyl)(methoxyimino)acetyl]amino]-2-carboxy-8-oxo-5-thia-1-azabicyclo[4,2,0]oct-2-en-3-yl]methyl-3-trimethylsilylpyridinium hydroxide, inner salt
To a suspension of [6R-[6α,7β(Z)]]-1-[7-[[(2-Amino-4-thiazolyl)(methoxyimino)acetyl]amino]-2-carboxy-8-oxo-5-thia-1-azabicyclo[4,2,0]oct-2-ene-2-carboxylic acid (2.73 g) in CH 2 Cl 2 (12 ml), N-methyl-N-trimethylsilyltrifluoroacetamide (3.74 ml) was added. After having stirred the mixture for 1.5 hr at room temperature, trimethylsilyl iodide (2.30 ml) was added to the reaction mixture, the stirring was continued for 0.5 hr at room temperature and then the reaction mixture was concentrated under reduced pressure. After having dissolved the residue in CH 3 CN (12 ml), THF (0.492 ml) was added and the mixture was stirred for 10 min to give a crude iodomethyl derivative as its CH 3 CN solution.
A half amount (volume) of the solution of iodomethyl derivative was added to a stirred solution of 3-trimethylsilylpyridine (545 mg) in CH 3 CN (2.5 ml) to stirr the mixture for 3 hr at room temperature and then H 2 O (0.290 ml) was added. The resulting precipitate was collected and washed with CH 3 CN followed by Et 2 O to give a yellowish brown powder (1.56 g).
After having dissolved the powder (500 mg) in H 2 O (50 ml), a trace amount of insoluble material was filtered off and the remaining aqueous solution was lyophilized. The powdery residue was purified by preparative thin layer chromatography (silica gel, acetone-H 2 O=4:1) followed by lyophilization to give the desired product (237 mg), as a pale yellow powder.
FAB-MS (m/z): 547 (M+H) + .
______________________________________.sup.1 HNMR(D.sub.2 O) δ ppm:______________________________________0.40 (9H, s, SiMe.sub.3),3.40 (2H, ABq, J = 18.0Hz, Δν = 32.0Hz, C.sub.4H),3.93 (3H, s, OMe),5.24 (1H, d, J = 5.0Hz, C.sub.6H),5.78 (1H, d, J = 5.0Hz, C.sub.7H),5.1-5.8 (2H, m, CH.sub.2N.sup.⊕),6.87 (1H, s, thiazolyl-H),7.8-8.2 ##STR12##8.4-9.0 ##STR13##______________________________________
IR (ν max KBr ) cm -1 : 3400, 1770, 1610, 1530, 1035.
EXAMPLE 2
[6R-[6α,7β(Z)]]-1-[7-[[(2-Amino-4-thiazolyl)(methoxyimino)acetyl]amino]-2-carboxy-8-oxo-5-thia-1-azabicyclo[4,2,0]oct-2-en-3-yl]methyl-4-trimethylsilylpyridinium hydroxide, inner salt
A solution of iodomethyl derivative (1/2 volume, prepared by similar reaction as described in Example 1) was added to a stirred solution of 4-trimethylsilylpyridine (545 mg) in CH 3 CN (2.5 ml). The mixture was stirred for 3 hr at room temperature and then H 2 O (0.290 ml) was added. The resulting precipitate was collected and washed with CH 3 CN followed by Et 2 O to give a yellowish brown powder (1.26 g).
After having dissolved the powder (500 mg) in H 2 O (50 ml), similar operations as described in Example 1 were carried out to give the desired product (190 mg), as a pale yellow powder.
FAB-MS (m/z): 547 (M+H) + .
______________________________________.sup.1 HNMR(D.sub.2 O) δ ppm:______________________________________0.38 (9H, s, SiMe.sub.3),3.38 (2H, ABq, J = 18.0Hz, Δν = 32.0Hz, C.sub.4H),3.94 (3H, s, OMe),5.25 (1H, d, J = 5.0Hz, C.sub.6H),5.77 (1H, d, J = 5.0Hz, C.sub.7H),5.1-5.8 (2H, m, CH.sub.2N.sup.⊕),6.91 (1H, s, thiazolyl-H),8.15 ##STR14##8.75 ##STR15##______________________________________
IR (ν max KBr ) cm -1 : 3400, 1770, 1610, 1530, 1035.
EXAMPLE 3
[6R-[6α,7β(Z)]]-1-[7-[[(2-Amino-4-thiazolyl)(methoxyimino)acetyl]amino]-2-carboxy-8-oxo-5-thia-1-azabicyclo[4,2,0]oct-2-en-3-yl]methyl-4-methoxy-3-trimethylsilylpyridinium hydroxide, inner salt
A solution of iodomethyl derivative (1/2 volume, prepared by similar reaction as described in Example 1) was added to a stirred solution of 4-methoxy-3-trimethylsilylpyridine (653 mg) in CH 3 CN (2.5 ml). The mixture was stirred for 3 hr at room temperature and then H 2 O (0.290 ml) was added. The resulting precipitate was collected and washed with CH 3 CN followed by Et 2 O to give a yellowish brown powder (1.73 g).
After having dissolved the powder (500 mg) in H 2 O (50 ml), similar operations as described in Example 1 were carried out to give the desired product (240 mg), as a pale yellow powder.
FAB-MS (m/z): 577 (M+H) + .
______________________________________.sup.1 HNMR(D.sub.2 O) δ ppm:______________________________________0.33 (9H, s, SiMe.sub.3),3.38 (2H, ABq, J = 18.0Hz, Δν = 32.0Hz, C.sub.4H),3.95 (3H, s, NOMe),4.08 (3H, s, COMe),5.0-5.4 (3H, m, C.sub.6H, and CH.sub.2N.sup.⊕),5.76 (1H, d, J = 5.0Hz, C.sub.7H),6.87 (1H, s, thiazolyl-H),7.34 ##STR16##8.1-8.8 ##STR17##______________________________________
IR (ν max KBr ) cm -1 : 3400, 1760, 1620, 1530, 1035.
EXAMPLE 4
[6R-[6α,7β(Z)]]-1-[7-[[(2-Amino-4-thiazolyl)(methoxyimino)acetyl]amino]-2-carboxy-8-oxo-5-thia-1-azabicyclo[4,2,0]oct-2-en-3-yl]methyl-4-(4,5-dihydro-4,4-dimethyl-2-oxazolyl)-3-trimethylsilylpyridinium hydroxide, inner salt
A solution of iodomethyl derivative (1/3 volume, prepared by similar reaction as described in Example 1) was added to a stirred solution of 4-(4,5-dihydro-4,4-dimethyl-2-oxazolyl)-3-trimethylsilylpyridine (596 mg) in CH 3 CN (2.5 ml). The mixture was stirred for 3 hr at room temperature and then H 2 O (0.196 ml) was added. The resulting precipitate was collected and washed with CH 3 CN followed by Et 2 O to give a yellowish brown powder (1.27 g).
After having dissolved the powder (500 mg) in H 2 O (50 ml), similar operations as desribed in Example 1 were carried out to give the desired product (198 mg), as a pale yellow powder.
FAB-MS (m/z): 644 (M+H) + .
______________________________________.sup.1 HNMR(D.sub.2 O) δ ppm:______________________________________0.40 (9H, s, SiMe.sub.3),1.42 ##STR18##3.42 (2H, ABq, J = 18.0Hz, Δν = 32.0Hz, C.sub.4H),3.91 (3H, s, OMe),4.33 (2H, s, OCH.sub.2)5.21 (1H, d, J = 5.0Hz, C.sub.6H),5.73 (1H, d, J = 5.0Hz, C.sub.7H),5.1-5.7 (2H, m, CH.sub.2N.sup.⊕),6.80 (1H, s, thiazolyl-H),8.13 ##STR19##8.8-9.0 ##STR20##______________________________________
IR (ν max KBr ) cm -1 : 3400, 1780, 1615, 1535.
EXAMPLE 5
[6R-[6α,7β(Z)]]-1-[7-[[(2-Amino-4-thiazolyl)(methoxyimino)acetyl]amino]-2-carboxy-8-oxo-5-thia-1-azabicyclo[4,2,0]oct-2-en-3-yl]methyl-4-carboxy-3-trimethylsilylpyridinium hydroxide, inner salt
N,O-Bis(trimethylsilyl)trifluoroacetamide (1.28 ml) was added to a suspension of 3-trimethylsilyl-4-pyridinecarboxylic acid (937 mg) in CH 3 CN (8.0 ml). The mixture was stirred for 0.5 hr at room temperature. To the reaction mixture, a solution of iodomethyl derivative (2/3 volume, prepared by similar reaction as described in Example 1) was added. The mixture was stirred for 3 hr at room temperature and then H 2 O (0.600 ml) was added. The resulting precipitate was collected and washed with CH 3 CN followed by Et 2 O to give a yellowish brown powder (1.73 g).
After having dissolved the powder (500 mg) in H 2 O (50 ml), similar operations as desribed in Example 1 were carried out to give the desired product (320 mg), as a pale yellow powder.
FAB-MS (m/z): 591 (M+H) + .
______________________________________.sup.1 HNMR(D.sub.2 O) δ ppm:______________________________________0.38 (9H, s, SiMe.sub.3)3.39 (2H, ABq, J = 18.0Hz, Δν = 32.0Hz, C.sub.4H),3.91 (3H, s, OMe),5.18 (1H, d, J = 5.0Hz, C.sub.6H),5.73 (1H, d, J = 5.0Hz, C.sub.7H),5.2-5.8 (2H, m, CH.sub.2N.sup.⊕),6.88 (1H, s, thiazolyl-H),7.73 ##STR21##8.6-8.8 ##STR22##______________________________________
IR (ν max KBr ) cm -1 : 3400, 1770, 1615, 1535, 1380.
PHARMACEUTICAL TEST EXAMPLE 1
(Antibacterial spectrum and antibacterial power)
Each series of dilution was prepared with use of testing compounds prepared by the Examples and control compound of Gentamicin as well as a liquid medium. The minimum inhibitory concentration (MIC in μg/ml) to each pathogen (seeding amount: 10 6 cells/ml) was determined, in accordance with the standard method (agar plate dilution method) by the Chemotherapy Society of Japan. Results are shown in following Table.
The control compound of Gentamicin has been known as one of water soluble basic antibiotics having a wider antibacterial spectrum and showing a higher antibacterial power but the results given in the Table apparently show a fact that the compounds according to the invention are superior than the Gentamicin in both of the antibacterial spectrum and antibacterial power.
______________________________________ ExamplesStrains 1 2 3 Gentamicin______________________________________E. coli NIH <0.20 <0.20 0.78 0.78E. coli K-12 0.39 0.78 0.78 0.78C. fleundii NIH 10018-68 <0.20 <0.20 0.78 0.39K. pneumoniae NCTC 9632 0.39 0.78 0.78 0.78S. typhi T-287 <0.20 0.39 0.39 0.78S. flexneri 2a EW-10 <0.20 0.39 0.39 3.13P. vulgaris OX-19 <0.20 <0.20 <0.20 3.13P. rettgeri NIH 96 <0.20 <0.20 <0.20 <0.20P. aeruginosa Nc-5 1.56 6.25 6.25 3.13______________________________________
PHARMACEUTICAL TEST EXAMPLE 2
(Acute toxicity)
Some compounds according to the invention were tested to evaluate their acute toxicity in mouse.
ICR mice of male sex (body weight of 29 to 32 g) and female sex (body weight of 21 to 26 g), each mouse having age of 6 weeks were selected for the experiment. Each of the testing compounds (Example 1 to 3) was dissolved in physiological salt solution and the resulting solution was dosed to the mice in oral or abdominal route.
A weighing and observation on general behavior were carried out just before the dosage and each day after the same. Each of died mice was subjected without delay to an autopsy to check same. All of living mice were killed at 14th day from the dosage to carry out the autopsy.
An LD 50 was calculated in accordance with the Leed and Munch's method to find that the value of each compound is more than 1 g/kg.
PRESCRIPTIONAL EXAMPLE 1 (INJECTION)
The compound (0.5 g) prepared by the Example 1 was dissolved 0.9% NaCl solution to make total volume of the resulting solution to 10 ml. The solution was charged in a vial to seal the same.
PRESCRIPTIONAL EXAMPLE 2 (DRY POWDER FOR INJECTION)
The compound (0.5 g) prepared by the Example 2 was aseptically charged and sealed in a glass vial.
The dry powder accommodated in the vial can be dissolved in distilled water for injection to make total volume of 10 ml and then immediately injected to a patient.
PRESCRIPTIONAL EXAMPLE 3 (TABLET)
Following ingredients were composed and treated in a conventional manner to prepare tablets.
______________________________________Product of Example 3 150 (mg)Lactose 20Corn starch 5Hydroxypropylcellulose 4Magnesium stearate 1 180 mg/tablet______________________________________
PRESCRIPTIONAL EXAMPLE 4 (GRANULE)
Following ingredients were composed and treated in a conventional manner to prepare granules.
______________________________________Product of Example 1 150 (mg)Lactose 20Corn starch 5Hydropropylcellulose 5 180 mg/package______________________________________
PRESCRIPTIONAL EXAMPLE 5 (OINTMENT)
Following ingredients were composed and treated in a conventional manner to prepare an ointment.
______________________________________Product of Example 1 0.5 (g)Vaselline 100 100.5 g______________________________________
PRESCRIPTIONAL EXAMPLE 6 (SUPPOSITORY)
Following ingredients were composed and treated in a conventional manner to prepare suppositories.
______________________________________Product of Example 3 0.2 (g)Witep-Sol H-12 1.6Maleic acid 0.2 2.0 g/piece______________________________________
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A cephalosporin derivative represented by the formula ##STR1## wherein R is an organic residue known on β-lactam antibiotics and Q is a radical of ##STR2## dotted-line means a possible double bond, R 1 is hydrogen or monovalent substituent, R 2 , R 3 and R 4 are mono-valent substituent, respectively,
a salt thereof, a process for the manufacture thereof and a pharmaceutical agent comprising same.
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BACKGROUND OF THE INVENTION
This invention relates to an electrostatic chuck for holding a semiconductor wafer in a fixed plane relative to said chuck, which chuck comprises an electrically conductive member separated from said fixed plane by a layer of dielectric material, means for electrically contacting the wafer, and means for supporting the wafer in said plane.
In the manufacture of semiconductor devices it is sometimes necessary to clamp a semiconductor wafer substantially flat against a support so that one of its surfaces can be subjected to a processing treatment. Such a treatment may involve directing charged particles towards the wafer. For example, selected areas of the wafer can have their conductivity type modified by the implantation of ions. As another example, an electron sensitive resist may be coated on the wafer surface and the resist can then be selectively exposed to a beam of electrons. During these processing treatments it is important that the wafer be held flat against the support. For this purpose it is known to use a so-called electrostatic chuck.
United Kingdom Patent Specification GB No. 1,443,215 describes an electrostatic chuck which essentially comprises a substantially flat electrically conductive support member coated with a layer of dielectric material. A semiconductor wafer can be supported on the dielectric layer which thus prevents physical and electrical contact between the facing surfaces of the wafer and the support. The chuck also has means for electrically contacting the wafer so that a potential difference can be applied between the wafer and the support. Such a potential difference sets up an electrostatic clamping force across the dielectric layer so that the wafer is then held substantially flat against the dielectric layer. With the wafer thus clamped, its surface remote from the support can be subjected to the appropriate processing treatment.
Unfortunately, processing treatments involving the use of beams of charged particles as mentioned above are responsible for the generation of thermal energy in the wafer. This thermal energy can cause expansion and local distortion of the wafer if the heat generated cannot be readily dissipated. The chuck described in GB No. 1,443,215 relies on firm and even clamping of the wafer to obtain good heat exchange between the wafer and the support. However, the wafer is actually clamped against the dielectric layer which separates the wafer from the support. In general, the thermal conductivity of dielectric materials is not particularly high. Thus the dielectric layer, which is necessary for electrostatic attraction, acts as a barrier to the efficient flow of heat from the wafer to the support so that it is necessary to use thin layers of high thermal conductivity dielectric in order to obtain adequate heat conduction. It can be said, therefore, that for adequate clamping and good heat transfer between the wafer and the support, the chuck described in GB No. 1,443,215 must have a thin layer of high thermal conductivity dielectric material with a high dielectric constant and a high dielectric strength. Clearly the choice of materials and design flexibility is severely restricted by these requirements.
SUMMARY OF THE INVENTION
According to the present invention, an electrostatic chuck having the features mentioned above is characterized in that it further comprises thermally conductive portions for contacting the wafer, and in that the electrically conductive member has parts which extend laterally between said thermally conductive portions, the dielectric layer extending at least on said parts.
Thus, when a wafer is located on an electrostatic chuck in accordance with the invention it contacts the thermally conductive portions. When a potential difference is applied between the wafer and the electrically conductive member the wafer is pulled by electrostatic attraction against the thermally conductive portions so that heat can flow freely away from the wafer.
Because the wafer contacts the thermally conductive portions there is a relaxation of the requirements for the dielectric layer. First, there is no longer any need for it to have such a high thermal conductivity, and second, it is not necessary to use such thin dielectric layers. This allows a much wider choice of dielectric materials than was possible in the prior art chuck described above. Also, there is an increased freedom of chuck design resulting from less stringent requirements for the thickness of the dielectric layer.
It is preferable for the thermally conductive portions to be sufficiently rigid so that they can support the semiconductor wafer in a fixed plane. This eliminates the need for separate members to support the wafer, thus simplifying chuck design and manufacture.
The effectiveness of heat flow away from the semiconductor wafer can be enhanced by the provision of a heat sink which can be constituted by a thermally conductive support having a periphery in thermal contact with the thermally conductive portions.
The thermally conductive portions may themselves be electrically conductive. In this case the thermally conductive portions are electrically isolated from the electrically conductive member. As the thermally conductive portions support the semiconductor wafer it is electrically contacted by them so that the thermally conductive portions also constitute the electrical contact means for the wafer. Thus the wafer is electrically contacted at the back surface (i.e. the surface opposite that which is to be subjected to the processing treatment) without the need for any additional contact means. In contrast, the known chuck mentioned above employs special contact means in the form of a metal block having a V-shaped recess. The semiconductor wafer can be located such that it abuts the edge of this recess thereby making electrical contact with the edge of the wafer.
In one form of a chuck in accordance with the invention, the thermally conductive portions protrude beyond the dielectric layer so that the dielectric is spaced apart from the fixed plane. When a semiconductor wafer is located on such a chuck there is no physical contact between the wafer and the dielectric. An advantage of this is that it maximizes the contact pressure between the wafer and the thermally conductive portions for optimum heat transfer. A further advantage is that any small particles of debris which may be present at the area of the chuck where the wafer is to be clamped tend to be attracted onto the dielectric. Because the thermally conductive portions supporting the wafer protrude beyond the dielectric layer, the wafer is held away from any such debris so that the flatness of the wafer is not affected. With the known chuck described above the surface (i.e. the dielectric layer) against which the semiconductor wafer is electrostatically attracted is substantially flat so that the presence of any particles of debris would tend to cause localized bowing of the wafer, which is most undesirable.
The thermally conductive portions may be pillars having flat end faces for supporting the semiconductor wafer in a fixed plane relative to the chuck. The conductive member can then be a grid, where the conductive pillars extend through the meshes of said grids.
Alternatively, the thermally conductive portions may be constituted by a thermally conductive grid. The electrically conductive member then has parts which extend between the meshes of this grid. The number of constituent parts of such a chuck is minimized when the electrically conductive member comprises a plate which is integral with the parts which extend into the meshes of the grid. By minimizing the number of constituent parts, manufacture of such an electrostatic chuck can be simplified.
Both of these gridded structures are compatible with known X-ray alignment techniques which require holes to be provided all the way through the chuck. When the conductive member is in the form of a grid these holes can be provided merely by omitting conductive pillars from appropriately located meshes in the grid. Alternatively, when the thermally conductive portions are in the form of a grid the holes can be provided as appropriately located apertures in the electrically conductive member, each of these apertures being aligned with a mesh of the grid.
BRIEF DESCRIPTION OF THE DRAWING
Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which:
FIG. 1 is a cross-sectional view, taken on the line I--I' of FIG. 2, of a semiconductor wafer located on an electrostatic chuck in accordance with the invention;
FIG. 2 is a plan view, taken from above, of the semiconductor wafer and the chuck of FIG. 1, the semiconductor wafer being partially cut away; and
FIG. 3 is a cross-sectional view of a semiconductor wafer on a different embodiment of an electrostatic chuck in accordance with the invention.
It should be noted that, for the sake of clarity, the Figures are not drawn to scale.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1 and 2 show a semiconductor wafer 1 located on an electrostatic chuck 2 which comprises a thermally conductive support 3,5 made of, for example, aluminum. For positioning the wafer 1 on the chuck, locating pins 13a, 13b are provided so that the flat edge 1a of wafer 1 can abut pins 13a and the rounded edge 1b abuts pin 13b so that the location of the wafer 1 is uniquely defined. The support has a peripheral portion 3 which may be 6 mm. thick and a thinner, perforated central portion 5 having a thickness of approximately 3.5 mm. The central portion 5 has perforations or apertures 6 which are circular in cross-section with a diameter of 3 mm. The electrostatic chuck also comprises thermally conductive portions in the form of copper pillars 7 which are secured in the apertures 6. The pillars 7, which are 6 mm. long and have a diameter of 3 mm., are in thermal contact with the central portion 5 of the support and also with the peripheral portion 3 which, because of its relatively large size, can act as a heat sink.
The pillars 7 have flat end faces 8 which lie in the same fixed plane so that the semiconductor wafer 1 can bear on them as well as on the major surface 9 of the peripheral portion 3 of the support. In this way the wafer can be supported in a fixed plane relative to the electrostatic chuck 2. Moreover, because the pillars 7 are made of metal they are electrically (as well as thermally) conductive so that the semiconductor wafer 1 is electrically contacted at its back surface (i.e. the surface facing the electrostatic chuck 2) by the pillars 7.
The chuck 2 also has an electrically conductive member in the form of a grid electrode 10 which may be made of, for example, aluminum. Essentially the grid 10 is circular, having a diameter of 90 mm. and a thickness of 1.3 mm. The meshes of the grid 10 are constituted by circular apertures 11 which have a diameter of 5 mm. The grid 10 has parts which extend between the pillars 7 because it is located such that the pillars 7 extend through the apertures 11, but the pillars 7 and grid 10 are mutually insulated by a layer of dielectric material 12. The layer 12 of dielectric material which may be, for example, an epoxy resin surrounds the grid 10 so that, in addition to insulating the grid from the pillars 7 the grid 10 is also insulated from the central portion 5 of the support. The separation of the grid 10 from both the pillars 7 and the central portion 5 of support 2 is, for example, 1 mm., the dielectric layer 10 filling the whole space between these various members. In addition the dielectric layer is present on the upper surface of grid 10 but this part of layer 10 has a thickness of approximately 200 micrometers. As explained in more detail hereinafter the pillars 7 may protrude from the dielectric layer 12 so that the semiconductor wafer 1 is spaced apart from layer 12 by approximately 10 micrometers.
The use of a transparent epoxy resin for the dielectric layer 12 is particularly advantageous because any major defects in the dielectric layer 12 can be detected visually before the chuck is actually used. The offending part of the dielectric layer can then be removed, e.g. by drilling, and replaced with fresh material.
To hold the semiconductor wafer 1 against the chuck 2 a potential difference is applied between the wafer 1 and the grid electrode 10. Typically this potential difference is 4 kV. Electrical contact is made to the back surface of wafer 1 via pillars 7 from the support 2 and a bias potential of, for example, approximately 4 kV is applied to grid 10 via an electrical connection 4 extending through the central portion 5 of the support and through the dielectric layer 12. Thus an electrostatic clamping force is established across the dielectric layer 12 so that the wafer 1 is held in a fixed plane against the pillars 7 of the chuck 2. The magnitude of the clamping force is proportional to the square of the potential difference between wafer 1 and electrode 10, directly proportional to the dielectric constant of layer 12, and inversely proportional to the square of the distance between the wafer 1 and the grid 10. For an epoxy resin with a dielectric constant of approximately 4 and when the thickness of the dielectric layer 12 is about 200 micrometers, the clamping force per unit area is approximately 5×10 4 Nm -2 . The chuck may have a total of 55 pillars 7 over an area of 50 cm 2 . (For the sake of clarity not all of these pillars are shown in FIG. 2).
As shown in FIG. 2 the chuck 2 has a symmetrical distribution of pillars 7. In order that the wafer is held evenly against the chuck it is preferable that the pillars 7 are relatively closely spaced to avoid localized bowing of the wafer. This is also consistent with the need to avoid temperature variations across the wafer 1. The greater the number of pillars 7 and the closer is their spacing the more efficient can be the transfer of heat from the wafer to the thick peripheral heat sink 3 of the support. But, as far as the number of pillars is concerned, a compromise has to be reached because the contact pressure due to electrostatic attraction is reduced as the number of pillars 7 is increased. However, because the pillars 7 protrude from dielectric layer 12, the wafer 1 contacts the chuck 2 only at the end faces 8 of the pillars 7 and at the inner periphery of the major surface 9. By limiting the contact area in this way the contact pressure (i.e. force per unit area) is maximized. This is beneficial because the efficiency of heat transfer between the wafer 1 and the pillars 7 depends on the contact pressure.
As mentioned previously, there is another advantage attaching to the fact that the pillars 7 protrude from the dielectric layer, namely that any small particles of debris which may be present at the area of the chuck 2 where the wafer 1 is to be clamped tend to be attracted onto the dielectric layer 12. Because the wafer 1 is spaced apart from layer 12 it is also held away from any such particles of debris so that the flatness of the wafer is not affected.
Once the potential difference is applied between the wafer 1 and the grid 10, as mentioned above, the front surface of the semiconductor wafer (i.e. the surface directed away from the chuck 2) can be subjected to the appropriate processing treatment. For example, a layer of electron sensitive resist (not shown in the Figures) present on the front surface of the wafer 1 may be exposed to a beam of electrons to define a pattern in the resist. The impinging electrons cause heat to be generated in the semiconductor wafer. This heat can readily flow away from the wafer through pillars 7 to the thick peripheral portion 5 of the support, which thus acts as a heat sink.
The chuck described above can be made in a relatively straightforward manner as follows. The support is made from a 6 mm. thick circular block of aluminum which is machined to form the thinner central portion 5 of the support. For use with 100 mm. semiconductor wafers this central portion may have a diameter of 95 mm. and the diameter of the whole support may be 150 mm. The central well in the support is filled with an epoxy resin which is then machined down to a thickness of approximately 1 mm. Next, the apertures 6 are formed by drilling through the central portion 5 of the support and through the epoxy resin. At this stage also a hole is drilled to accommodate the electrical connection 4. The pillars 7 are then pressed into the apertures 6 after which the grid 10 is provided so that the pillars 7 extend through the meshes 11 as described above. Epoxy resin is provided around and above the grid 10 to form the dielectric layer 12 which can then be cut back so that the pillars 7 protrude from it. Alternatively, the pillars 7 can be gold-plated in a conventional manner. The thickness of this plating is approximately 10 micrometers. The chuck is completed by screwing locating pins into appropriate locations on the peripheral portion 3 of the support and providing the electrical connection 4 which is insulated from the central portion 5 of the support.
A different embodiment of an electrostatic chuck in accordance with the invention will now be described with reference to FIG. 3. As before, this chuck 22 comprises a thermally conductive support made of, for example, aluminum. The support again has a thick peripheral portion 23 which may be 6 mm. thick and a thinner, perforated central portion 25 having a thickness of for example 3 mm. The central portion has apertures 26 which may be circular in cross-section with a diameter of 10 mm. The central portion 25 is thus in the form of a grid which constitutes the thermally conductive portions for supporting a semiconductor wafer 1. The grid 25 is integral with the peripheral portion 23 of support 22 so that heat can be transferred readily from the semiconductor wafer to this peripheral portion 23 which again acts as a heat sink.
The chuck also comprises a plurality of electrically conductive parts 27 which extend into the meshes i.e. the apertures 26 but are insulated therefrom by a dielectric layer 30 which again may be an epoxy resin. The parts 27 are integral with an electrically conductive plate 31 which, like the members 27, may be made of aluminum. This plate 31 is also insulated from the support 22 by dielectric layer 30. As in the previous embodiment the thermally conductive portions for supporting the wafer, that is to say the grid 25, protrude from the dielectric layer 30. The wafer 1 is electrostatically clamped in a fixed plane relative to the chuck by applying a potential difference between the wafer 1 and the electrically conductive member constituted by parts 27 and plate 31. As before the thermally conductive portions, i.e. grid 25, also serve as electrical contacts for the back surface of the semiconductor wafer 1 so that an electric potential can be applied to the wafer 1 simply by applying a potential to the support 22. An electric potential can be applied directly to plate 31 to set up the required potential difference.
To make this chuck 22, the starting material is again a circular slab of, for example, aluminum having the same dimensions as before. The central thinner portion is formed by machining, after which the apertures 26 are formed by drilling or etching. Thus the central portion 25 of the support takes on the form of a grid. The support can then be rested on a flat surface with the grid engaging that surface. In other words the support 22 is inverted with respect to its position shown in FIG. 3. A layer of dielectric material 30, for example an epoxy resin, is provided on the whole of the upper exposed surface of the support and on the exposed parts of the flat surface on which the support bears. After removing the chuck from the flat surface on which it is resting the electrically conductive member in the form of members 27 integral with plate 31 is pressed into the insulating layer 30 such that this layer 30 has a thickness between the members 27 and the flat surface of about 200 micrometers. The insulating layer is then machined flat so that it does not protrude above the surface 29 of the support 22, after which this surface 29 can be gold-plated in conventional manner so that it protrudes about 10 micrometers from the dielectric layer 30. As an alternative to plating the surface 29, the dielectric layer 30 can be cut back to achieve the same effect. In either case when a semiconductor wafer 1 is located on the chuck 22 it is supported by the grid 25 and the peripheral portion 23 of support 22 so that the wafer 1 is spaced apart from the dielectric layer 30. In order that the wafer can be correctly located on the chuck 22 three locating pins are provided as in the previous embodiment.
The invention is not limited to the particlar embodiments described above. To the contrary, many modifications are possible within the scope of the invention. For example different materials may be used for the different elements of the electrostatic chuck. In this context it is noted that the thermally conductive portions, that is to say the pillars 7 in the first embodiment and the grid 25 in the second embodiment, may be made of a material which is thermally but not electrically conductive. In this case it would be necessary to provide other electrical contact means for example a recessed metal block on the front surface (9,29) of the chuck for electrically contacting the semiconductor wafer.
Also, it is noted that it is not necessary for the thermally conductive portions to protrude from the dielectric layer. Instead, the dielectric layer may be co-planar with the upper surfaces of the thermally conductive members. Nor is it necessary for the dielectric layer to fill completely the space between the electrically conductive member and the other parts of the chuck. Thus, for example, the dielectric layer may fill only part of the space separating the thermally conductive portions from the electrically conductive member. Alternatively, this space may even be filled with an electrically insulating material different to that of the dielectric layer.
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An electrostatic chuck for holding a simiconductor wafer flat in a charged particle beam machine has thermally conductive portions for supporting the wafer. An electrically conductive member, for example a grid, has parts which extend between the thermally-conductive portions and is separated from the wafer by a dielectric layer. The wafer is clamped against the chuck by the electrostatic force set up across the dielectric layer when a potential difference is applied between the conductive wafer and the conductive member. Heat generated in the wafer by the bombardment of charged particles can be dissipated readily via the thermally conductive portions. The wafer can be electrically contacted at its back surface if the portions are also electrically conductive. To enhance thermal conduction away from the wafer, the conductive portions can protrude from the dielectric layer.
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FIELD OF THE INVENTION
[0001] The present invention relates generally to an iris retractor used in ophthalmic surgical procedures.
BACKGROUND OF THE INVENTION
[0002] There are various ophthalmic procedures that require the dilation of the pupil. For example, a lens with a cataract is typically removed from the eye by phacoemulsification. This procedure breaks up the lens typically with an ultrasonically driven tool. The tool has an aspiration port that aspirates the broken lens material from the patient's ocular-chamber. It is desirable to extend the pupil during phacoemulsification to provide the surgeon with a wide view of the lens. One technique for extending the pupil includes pulling back or retracting the iris with what is referred to as an iris retractor, and holding the iris at its outer edges.
SUMMARY OF THE INVENTION
[0003] The present invention seeks to provide an improved iris retractor, as is described more in detail hereinbelow.
[0004] There is thus provided in accordance with an embodiment of the present invention an iris retractor including a plurality of iris grabbing hooks disposed or formed at a distal end of slender elements, and a proximal handle at a proximal end of the slender elements, the slender elements resiliently moving between retracted and expanded positions by manipulation of the slender elements, wherein in the retracted position, the hooks are close to one another and the slender elements are close to one another, and wherein in the expanded position, the hooks are separate and spaced apart from each other and distal portions of the slender elements are separate and spaced apart from each other.
[0005] In accordance with an embodiment of the present invention a retaining element retains the slender elements in the retracted position until the handle is manipulated to move the slender elements to the expanded position.
[0006] In accordance with another embodiment of the present invention a portion of the retaining element is formed with a groove, and in the expanded position, the handle is received in the groove.
[0007] In accordance with yet another embodiment of the present invention the retaining element includes a groove formed in one of the slender elements for receiving therein the other slender element.
[0008] In accordance with still another embodiment of the present invention the slender elements are pivotally attached to one another at a pivot.
[0009] In accordance with an embodiment of the present invention a tip of the slender element includes a U-shaped hook with a short distal extension.
[0010] In accordance with an embodiment of the present invention a tip of the slender element extends from a proximal sleeve.
[0011] In accordance with an embodiment of the present invention the hook is retractable into the slender element.
[0012] There is also provided in accordance with an embodiment of the present invention a method for retraction of an iris including providing an iris retractor that includes a plurality of hooks disposed or formed at a distal end of slender elements, and a proximal handle at a proximal end of the slender elements, the slender elements resiliently moving between retracted and expanded positions by manipulation of the handle, wherein in the retracted position, the hooks are close to one another and the slender elements are close to one another, and wherein in the expanded position, the hooks are separate and spaced apart from each other and distal portions of the slender elements are separate and spaced apart from each other, inserting the slender elements in the retracted position through a small incision near a limbus of an eye, manipulating the handle to move the slender elements to the expanded position, and grasping and retracting a portion of the iris with the hooks.
[0013] The incision for insertion of the slender elements can be made at a different position than an incision for phacoemulsification.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The present invention will be understood and appreciated more fully from the following detailed description taken in conjunction with the drawings in which:
[0015] FIGS. 1A-1C are simplified perspective, top-view and side-view illustrations, respectively, of an iris retractor, in a non-expanded orientation, constructed and operative in accordance with an embodiment of the present invention;
[0016] FIGS. 1D-1E are simplified perspective and side-view illustrations, respectively, of the iris retractor of FIGS. 1A-1C , in the non-expanded orientation placed on an eye;
[0017] FIGS. 2A-2C are simplified perspective, side-view and top-view illustrations, respectively, of the iris retractor of FIGS. 1A-1C , in a partially expanded orientation, in accordance with an embodiment of the present invention;
[0018] FIGS. 3A-3C are simplified perspective, side-view and top-view illustrations, respectively, of the iris retractor of FIGS. 1A-1C , in a fully expanded orientation, in accordance with an embodiment of the present invention;
[0019] FIGS. 3D-3E are simplified side-view and perspective illustrations, respectively, of the iris retractor of FIGS. 1A-1C , in the fully expanded orientation placed on the eye;
[0020] FIGS. 4A-4C are simplified perspective, side-view and top-view illustrations, respectively, of an iris retractor, in a non-expanded orientation, constructed and operative in accordance with another embodiment of the present invention;
[0021] FIGS. 4D-4E are simplified perspective and side-view illustrations, respectively, of the iris retractor of FIGS. 4A-4C , in the non-expanded orientation placed on an eye;
[0022] FIGS. 5A-5C are simplified perspective, top-view and side-view illustrations, respectively, of the iris retractor of FIGS. 4A-4C , in an expanded orientation, in accordance with an embodiment of the present invention;
[0023] FIGS. 5D-5E are simplified side-view and perspective illustrations, respectively, of the iris retractor of FIGS. 4A-4C , in the expanded orientation placed on the eye;
[0024] FIG. 5F is a simplified perspective illustration of a modified version of the iris retractor of FIGS. 4A-4C , in accordance with an embodiment of the present invention;
[0025] FIGS. 6A-6C are simplified perspective, side-view and top-view illustrations, respectively, of an iris retractor, in a non-expanded orientation, constructed and operative in accordance with yet another embodiment of the present invention;
[0026] FIGS. 6D-6E are simplified side-view and perspective illustrations, respectively, of the iris retractor of FIGS. 6A-6C , in the non-expanded orientation placed on an eye;
[0027] FIGS. 7A-7C are simplified perspective, top-view and side-view illustrations, respectively, of the iris retractor of FIGS. 6A-6C , in an expanded orientation, in accordance with an embodiment of the present invention;
[0028] FIGS. 7D-7E are simplified side-view and perspective illustrations, respectively, of the iris retractor of FIGS. 7A-7C , in the expanded orientation placed on the eye;
[0029] FIGS. 8 and 9 are simplified perspective illustrations of different tips for the iris retractor of any of the above embodiments, in accordance with different embodiments of the present invention;
[0030] FIG. 9A is a simplified perspective illustration of the iris retractor with the distal extension of FIG. 8 or 9 in use, in accordance with an embodiment of the present invention;
[0031] FIGS. 10A-10E are simplified perspective illustrations of a retractable tip for the iris retractor of any of the above embodiments, in accordance with an embodiment of the present invention, shown gradually from fully extended to fully retracted positions;
[0032] FIG. 11 is a simplified pictorial illustration of an iris retractor, constructed and operative in accordance with another embodiment of the present invention;
[0033] FIGS. 12A-12D are simplified pictorial illustrations of an iris retractor, constructed and operative in accordance with yet another embodiment of the present invention;
[0034] FIGS. 13A-13H are simplified pictorial illustrations of a manipulator for operating the iris retractor of FIGS. 12A-12D , constructed and operative in accordance with an embodiment of the present invention;
[0035] FIGS. 14A-14D are simplified pictorial illustrations of an iris retractor, constructed and operative in accordance with still another embodiment of the present invention; and
[0036] FIGS. 15A-15E are simplified pictorial illustrations of an iris retractor, constructed and operative in accordance with another embodiment of the present invention.
DETAILED DESCRIPTION OF EMBODIMENTS
[0037] Reference is now made to FIGS. 1A-3C , which illustrate an iris retractor 10 , constructed and operative in accordance with a non-limiting embodiment of the present invention.
[0038] Iris retractor 10 includes a plurality of iris grabbing hooks 12 ( FIGS. 2A-3C ) disposed or formed at a distal end of one or more slender elements 14 . In the illustrated embodiment, there are two slender elements 14 . The slender elements 14 are arranged to move through a retaining element 16 from a fully retracted position ( FIGS. 1A-1C ) to a partially expanded position ( FIGS. 2A-2C ) to a fully expanded position ( FIGS. 3A-3C ). A proximal portion 18 of retaining element 16 is formed with a groove 19 . The proximal ends of slender elements 14 terminate in a proximal handle 20 . The slender elements 14 may be joined as a single element before connection to handle 20 or may be joined at the handle 20 . In the fully expanded position, handle 20 is pushed completely into groove 19 and is squeezed and held in this position by the side walls of groove 19 . (Alternatively, handle 20 may “click” into groove 19 . Accordingly, there can be a fixed configuration, wherein handle 20 clicks into groove 19 and slender elements 14 have a fixed expansion, or an adjustable expansion configuration, wherein the more the slender elements 14 are inserted into the eye the larger is their lateral expansion.) Retaining element 16 retains slender elements 14 in the retracted position until handle 20 is pushed towards groove 19 .
[0039] Slender elements 14 and hooks 12 may be constructed of a metal or plastic wire, such as but not limited, NITINOL or stainless steel or a medically safe plastic with suitable resilience, e.g., a shape memory polymer plastic.
[0040] FIGS. 1D-1E illustrate a pair of iris retractors 10 in a non-expanded orientation (i.e., retracted position) placed on an eye. A portion of retaining element 16 abuts against the cornea 22 , typically but not necessarily at the limbus 23 . As seen in the figures, iris retractor 10 is inserted through a small incision (e.g., 1.0-1.5 mm incision) at the limbus 23 . Retaining element 16 prevents iris retractor 10 from encroaching too much into the cornea 22 .
[0041] Pushing handle 20 towards retaining element 16 deploys slender elements 14 and hooks 12 out of retaining element 16 . As seen in FIGS. 3D-3E , hooks 12 grab and hook onto the iris 24 and retract the iris 24 for exposing the lens 25 to provide a good working opening for the surgeon. Retaining element 16 anchors the retractor 10 by applying a counter force on the outside of the limbus 23 .
[0042] Hooks 12 are separate and spaced apart from each other upon distal movement of slender elements 14 through retaining element 16 . Thus, a single iris retractor provides spaced apart retraction points, as opposed to some prior art iris retractors which only work at a single point.
[0043] The incision for insertion of the iris retractor may be made at a different position (e.g., perpendicular thereto) than the incision made for phacoemulsification. This is advantageous because in this manner the iris retractor does not get in the way of the surgeon.
[0044] Reference is now made to FIGS. 4A-5E , which illustrate an iris retractor 30 , constructed and operative in accordance with another embodiment of the present invention.
[0045] Iris retractor 30 includes a plurality of hooks 32 disposed or formed at a distal end of one or more slender elements 34 . In the illustrated embodiment, there are two slender elements 34 . The proximal ends of slender elements 34 terminate in a proximal handle 40 . Handle 40 and slender elements 34 are made of a resilient, flexible material (e.g., metal or plastic) to form a kind of resilient tweezers or pliers. The slender elements 34 are held in the non-expanded (retracted) orientation by a retaining element 36 (which may be formed as a loop) of the slender elements 34 being caught in one or more proximal grooves 38 formed in the other slender element 34 . Another option for keeping iris retractor 30 in its non-expanded state is by pressing elements 37 , without slender elements 34 being caught in grooves 38 .
[0046] FIGS. 4D-4E illustrate a pair of iris retractors 30 in a non-expanded orientation (i.e., retracted position) placed on the eye. A portion of retaining element 36 abuts against the cornea 22 , typically but not necessarily at the limbus 23 .
[0047] Squeezing handle 40 releases the slender element 34 that is initially caught in groove 38 of retaining element 36 . (For the other option mentioned above, iris retractor 30 moves to the expanded position by releasing elements 37 .) By virtue of their resilience, slender elements 34 spring outwards to the expanded position in FIGS. 5A-5E . As seen in FIGS. 4A-5E , the geometry of iris retractor 30 enables expansion of hooks 32 without resulting in significant expansion in the area of retaining elements 36 .
[0048] As seen in FIGS. 5D-5E , hooks 32 grab and hook onto the iris 24 and retract the iris 24 for exposing the lens 25 to provide a good working opening for the surgeon. Retaining element 36 anchors the retractor 30 by applying a counter force on the outside of the limbus 23 .
[0049] Reference is now made to FIG. 5F , which illustrates a modified version of the iris retractor 30 , in accordance with an embodiment of the present invention. In this embodiment, iris retractor 30 is provided with a flexible clip 42 in handle 40 . This design allows making the retractor smaller and may provide more spring (expansion) force.
[0050] Reference is now made to FIGS. 6A-7E , which illustrate an iris retractor 50 , constructed and operative in accordance with yet another embodiment of the present invention.
[0051] Iris retractor 50 includes a plurality of hooks 52 disposed or formed at a distal end of one or more slender elements 54 . In the illustrated embodiment, there are two slender elements 54 , which pivot about a pivot 56 . The proximal ends of slender elements 54 terminate in a proximal handle 60 . Handle 60 , pivot 56 and slender elements 54 form a kind of scissors. Iris retractor 50 is normally expanded and slender elements 54 are held in the non-expanded (retracted) orientation by the resilience of handle 60 (thus handle 60 serves as the retaining element for initially holding the slender elements 54 in the retracted orientation.
[0052] FIGS. 6D-6E illustrate a pair of iris retractors 50 in a non-expanded orientation (i.e., retracted position) placed on the eye. A portion of iris retractor 50 (e.g., near the pivot 56 ) abuts against the cornea 22 , typically but not necessarily at the limbus 23 .
[0053] Manipulating handle 60 “scissors out” the slender elements 54 to the expanded position in FIGS. 7A-7E . As seen in FIGS. 7D-7E , hooks 52 grab and hook onto the iris 24 and retract the iris 24 for exposing the lens 25 to provide a good working opening for the surgeon. A portion of iris retractor 50 (e.g., near the pivot 56 ) anchors the retractor 50 by applying a counter force on the outside of the limbus 23 .
[0054] Reference is now made to FIGS. 8 and 9 , which illustrate different tips for the iris retractor of any of the above embodiments, in accordance with different embodiments of the present invention. In FIG. 8 , a tip 70 is shown that has a U-shaped hook with a short distal extension 72 . In FIG. 9 , the same tip 70 is shown extending from a proximal sleeve 74 . The sleeved hooks (as shown in FIG. 9 ) can be retracted as shown in FIG. 10 .
[0055] Reference is now made to FIG. 9A , which illustrates the iris retractor with the distal extension 72 of FIG. 8 or 9 in use, in accordance with an embodiment of the present invention. It is seen that distal extension 72 firmly and positively sets the tool against the edges of the iris, and thus helps ensure proper, reliable and safe retraction of the iris.
[0056] Reference is now made to FIGS. 10A-10E , which illustrate a sleeved hook 80 for the iris retractor of any of the above embodiments, in accordance with an embodiment of the present invention, shown gradually from fully extended to fully retracted positions. Sleeved hook 80 is similar to the hook shown on FIG. 9 , and may or may not have a distal extension like the embodiment of FIG. 9 . Any suitable retracting mechanism (not shown) may be used to retract and/or extend retractable hook 80 into and/or out of the slender elements.
[0057] Reference is now made to FIG. 11 , which illustrates an iris retractor 150 , constructed and operative in accordance with another embodiment of the present invention.
[0058] Iris retractor 150 includes a plurality of hooks 152 disposed or formed at distal ends of a first slender element 154 . The first slender element 154 may be adjustable in length, such as by means of a flexible and extendable member 155 at a central portion thereof. A second slender element 156 (which may be arranged to move through a guide element, not shown, similar to that described above) is pivotally attached to first slender element 154 . An anchor element 158 is mounted at a proximal position on the second slender element 156 . The proximal end of second slender element 156 terminates in a proximal handle 160 .
[0059] As seen in FIG. 11 , the hooks 152 and first slender element 154 are inserted through a small incision at the limbus 144 and are manipulated by the surgeon so that hooks 152 spread apart and retract the iris 134 . Anchor element 158 anchors the retractor by applying a counter force on the outside of limbus 144 .
[0060] Reference is now made to FIGS. 12A-12D , which illustrate an iris retractor 170 , constructed and operative in accordance with another embodiment of the present invention.
[0061] Iris retractor 170 includes a plurality of hooks 172 disposed or formed at a distal end of one or more slender elements 174 . In the illustrated embodiment, there are two slender elements 174 . The proximal ends of slender elements 174 terminate in a proximal handle 176 . Handle 176 and slender elements 174 are made of a resilient, flexible material (e.g., metal or plastic) to form a kind of resilient tweezers or pliers. The hooks 172 in this embodiment curve back onto slender elements 174 and may optionally abut against slender elements 174 .
[0062] FIG. 12C illustrates iris retractor 170 in a non-expanded orientation inserted through a small incision at the limbus 23 . FIG. 12D illustrates iris retractor 170 in an expanded orientation, wherein hooks 172 grab and hook onto the iris 24 and retract the iris 24 for exposing the lens to provide a good working opening for the surgeon.
[0063] Reference is now made to FIGS. 13A-13H , which illustrate a manipulator 180 , for operating iris retractor 170 , constructed and operative in accordance with an embodiment of the present invention.
[0064] Manipulator 180 includes a retaining element 181 pivotally connected to a toggle lever 182 , which is in turn pivotally connected at a pivot 183 on a distal end of a handle 184 . The distal end of a handle 184 includes an anvil 185 formed with a hole 186 through which retaining element 181 passes. Handle 176 of iris retractor 170 fits on a lug 187 (e.g., pin) that protrudes from the bottom side of anvil 185 . Lug 187 fits into the center of handle 176 .
[0065] In FIGS. 13A , 13 B, 13 E and 13 F, toggle lever 182 is moved to the position wherein retaining element 181 is moved down to clamp around the slender elements 174 of iris retractor 170 , thus retaining slender elements 174 in the non-expanded orientation (retracted position). In FIGS. 13C , 13 D, 13 G and 13 H, toggle lever 182 is moved to the position (indicated by arrow F) wherein retaining element 181 is moved up to release the slender elements 174 of iris retractor 170 , thus allowing slender elements 174 to expand to the expanded orientation.
[0066] Reference is now made to FIGS. 14A-14D , which illustrate an iris retractor 190 , constructed and operative in accordance with another embodiment of the present invention.
[0067] Iris retractor 190 includes a plurality of hooks 192 disposed or formed at a distal end of one or more slender elements 194 . In the illustrated embodiment, there are two slender elements 194 . The proximal ends of slender elements 194 terminate in a proximal handle 196 . Handle 196 and slender elements 194 are made of a resilient, flexible material (e.g., metal or plastic or shape memory) to form a kind of resilient tweezers or pliers. Handle 196 in this embodiment is sufficiently resilient such that it flattens into an oblong shape when squeezed, as seen in FIG. 14B . Handle 196 springs back to its original shape to move iris retractor 190 to the expanded orientation.
[0068] FIG. 14C illustrates iris retractor 190 in a non-expanded orientation inserted through a small incision at the limbus 23 . As mentioned before, handle 196 flattens into an oblong shape. FIG. 14D illustrates iris retractor 190 in an expanded orientation, wherein hooks 192 grab and hook onto the iris 24 and retract the iris 24 for exposing the lens to provide a good working opening for the surgeon.
[0069] Reference is now made to FIGS. 15A-15E , which illustrate an iris retractor 200 , constructed and operative in accordance with another embodiment of the present invention.
[0070] Iris retractor 200 includes a plurality of hooks 202 disposed or formed at a distal end of one or more slender elements 204 . In the illustrated embodiment, there are two slender elements 204 . The proximal ends of slender elements 204 form a proximal handle that includes two scissor handles 206 . Handles 206 are spring loaded by a biasing device 208 , such as a coil spring which has ends attached to the handles 206 .
[0071] FIG. 15D illustrates iris retractor 200 in a non-expanded orientation inserted through a small incision at the limbus 23 . Handles 206 are squeezed and held together so that slender elements 204 are retracted together, as shown in FIG. 15B . FIG. 15E illustrates iris retractor 200 in an expanded orientation, wherein hooks 202 grab and hook onto the iris 24 and retract the iris 24 for exposing the lens to provide a good working opening for the surgeon.
[0072] It will be appreciated by persons skilled in the art that the present invention is not limited by what has been particularly shown and described hereinabove. Rather the scope of the present invention includes both combinations and subcombinations of the features described hereinabove as well as modifications and variations thereof which would occur to a person of skill in the art upon reading the foregoing description and which are not in the prior art.
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An iris retractor ( 10, 30, 50, 150, 170, 190, 200 ) including a plurality of hooks ( 12, 32, 52, 152, 172, 192, 202 ) disposed or formed at a distal end of slender elements ( 14, 34, 54, 154, 174, 194, 204 ), and a proximal handle ( 20, 40, 60, 176, 196, 206 ) at a proximal end of the slender elements ( 14, 34, 54, 154, 174, 194, 204 ), the slender elements ( 14, 34, 54, 154, 174, 194, 204 ) resiliently moving between retracted and expanded positions by manipulation of the slender elements, wherein in the retracted position, the hooks ( 12, 32, 52, 152, 172, 192, 202 ) are close to one another and the slender elements ( 14, 34, 54, 154, 174, 194, 204 ) are close to one another, and wherein in the expanded position, the hooks are separate and spaced apart from each other and distal portions of the slender elements are separate and spaced apart from each other.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to flash spinning of plexifilamentary film-fibril strands of polyester. This invention also relates to a spin fluid that Nay be used in existing commercial equipment with minimum changes in the equipment and to a spinning process using existing commercial equipment in which the spinning process utilizes compounds having very low ozone depletion potential, and the compounds are either non-flammable or exhibit very low flammability.
2. Description of the Related Art
U.S. Pat. No. 3,081,519 to Blades and White describes a flash spinning process for producing plexifilamentary film-fibril strands from fiber-forming polymers. A solution of the polymer in a liquid, which is a non-solvent for the polymer at or below its normal boiling point, is extruded at a temperature above the normal boiling point of the liquid and at autogenous or higher pressure into a medium of lower temperature and substantially lower pressure. This flash spinning causes the liquid to vaporize and thereby cool the extrudate which forms a plexifilamentary film-fibril strand of the polymer. Preferred polymers typically include crystalline polyhydrocarbons, such as polyethylene and polypropylene.
According to Blades and White, a suitable liquid for flash spinning (a) has a boiling point that is at least 25° C. below the melting point of the polymer; (b) is substantially unreactive with the polymer at the extrusion temperature; (c) should be a solvent for the polymer under the pressure and temperature set forth in the patent (i.e., these extrusion temperatures and pressures are respectively in the ranges of 165 to 225° C. and about 500 to 1500 psia (3447-10342 kPa)); (d) should dissolve less than 1% of the polymer at or below its normal boiling point; and (e) should form a solution that will undergo rapid phase separation upon extrusion to form a polymer phase that contains insufficient solvent to plasticize the polymer.
Commercial flashspun products have been made primarily from polyethylene plexifilamentary film-fibril strands and have typically been produced using trichlorofluoromethane as a spin agent. However, it would be desirable to make flashspun products from other types of polymers, such as polyesters, for example that have different properties than polyethylene.
Flash spinning of some types of polyester is known. U.S. Pat. No. 3,401,140 to Blades et al. discloses 10-80 weight percent of poly(ethylene terephthalate) in methylene chloride or in a mixture of methylene chloride and a perhaloalkane. U.S. Pat. No. 3,227,784 to Blades discloses poly(ethylene terephthalate) in mixtures of methylene chloride with cyclohexane, dichloro-difluoromethane, or dichloro-tetrafluoroethane.
Japanese Patent Publication J06257012, Sep. 13, 1994, discloses that a highly fibrillated network of fibers can be made of poly(ethylene terephthalate). The poly(ethylene terephthalate) may be present at 5-30% weight percent and flashspun from methylene chloride. The reference also states that poly(1,4-butylene terephthalate) can be used to make such fiber networks, but does not provide any details beyond the bare disclosure.
International Patent Publication WO 97/25459 (Jul. 17, 1997) assigned to E.I. du Pont de Nemours and Company (DuPont) is directed to plexifilamentary strands of various polyester blends, for example, poly(1,4-butylene terephthalate) (4GT) with poly(ethylene terephthalate) (2GT) and 4GT with poly(1,3-propylene terephthalate)(3GT). Poly(1,3-propylene terephthalate) may also be referred to as poly(trimethylene terephthalate). The reference also discloses plexifilamentary strands of polyester blended with various other polymers as well as 100% 4GT. The flash spinning was done using either a mixture of CO 2 and water or solvents such as methylene chloride mixed with decafluoropentane (HFC-4310 mee).
Microcellular and ultramicrocellular foams of 2GT are disclosed in U.S. Pat. No. 3,227,664 to Blades; U.S. Pat. No. 3,375,211 to Parrish; and U.S. Pat. No. 5,254,400 to Bonner et al., all assigned to DuPont. The solvents used were methylene chloride or mixtures of methylene chloride and dichloro-difluoromethane.
SUMMARY OF THE INVENTION
The invention includes a process for the preparation of plexifilamentary film-fibril strands of synthetic fiber-forming polymer which comprises flash spinning synthetic fiber-forming polyesters of poly(1,3-propylene terephthalate), copolymers of poly(1,3-propylene terephthalate), poly(1,4-butylene terephthalate) and copolymers of poly(1,4-butylene terephthalate). Spin agents that can be used include 1,1,2-trichloro-2,2-difluoroethane and isomers thereof; 1,2-dichloroethylene; and dichloromethane.
The invention includes a spin fluid comprising polyesters of poly(1,3-propylene terephthalate), copolymers of poly(1,3-propylene terephthalate), poly(1,4-butylene terephthalate) and copolymers of poly(1,4-butylene terephthalate) and selected spin agents as listed above.
The invention also includes processes for making microcellular and ultramicrocellular foams made from poly(ethylene terephthalate), poly(1,3-propylene terephthalate), or poly(1,4-butylene terephthalate).
The invention further includes processes for making blends of polyethylene with poly(ethylene terephthalate), poly(1,3-propylene terephthalate) or poly(1,4-butylene terephthalate).
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plot of the cloud point data for a solution comprised of various weight percentages of 2GT in dichloromethane.
FIG. 2 is a plot of the cloud point data for a solution comprised of 2GT in DCE.
FIG. 3 is a plot of the cloud point data for a solution comprised of various weight percentages of 3GT in HCFC-122.
FIG. 4 is a plot of the cloud point data for a solution comprised of various weight percentages of 4GT in HCFC-122.
FIG. 5 is a plot of the cloud point data for a solution comprised of 20 weight percent of various 3GT copolymers in HCFC-122.
FIG. 6 is a plot of the cloud point data for a solution comprised of 25 weight per cent of 26T in dichloroethylene/DCM.
DETAILED DESCRIPTION OF THE INVENTION
Processes for making plexifilamentary products of certain types of polyester are known, however, there are certain processes that have not heretofore been disclosed. As noted above, U.S. Pat. No. 3,081,519 provides a typical process for flash spinning.
The term “plexifilamentary strand”, as used herein, means a strand which is characterized as a three-dimensional integral network of a multitude of thin, ribbon-like, film-fibril elements of random length and with a mean film thickness of less than about 4 micrometers and a median fiber width of less than about 25 micrometers, that are generally coextensively aligned with the longitudinal axis of the strand. In plexifilamentary strands, the film-fibril elements intermittently unite and separate at irregular intervals in various places throughout the length, width and thickness of the strand to form the three-dimensional network.
A polyester polymer particularly useful in making the plexifilamentary strands of the invention is poly(1,3-propylene terephthalate) (3GT polyester). Previously, 3GT had not been readily available because an ingredient used to make it, 1,3-propanediol,was itself difficult to make. Recent developments in the production of 1,3-propanediol have made 3GT more readily available for uses as provided herein. It has been found that certain solvents are particularly suited for making the 3GT plexifilamentary strands of the subject invention, i.e., 1,1,2-trichloro-2,2-difluoroethane (HCFC-122) and isomers thereof, 1,2-dichloroethylene (DCE), dichloromethane (or methylene chloride), and also mixtures of HCFC-122 and dichloromethane and mixtures of DCE and dichloromethane. Dichloromethane is a very good solvent for polyesters and may be used as a primary spin agent or as a co-spin agent with DCE or with HCFC-122 to lower the cloud point pressure of the mixture as may be needed. It should be noted that the 1,2-dichloroethylene can be present in either cis- or trans- form.
Although dichloromethane is a good flash spinning agent for polyesters, it has relatively low dielectric strength (about 45 KV/cm). U.S. Pat. No. 3,851,023 to Brethauer et al. discloses that in the production of plexifilamentary webs it is advantageous to subject the flashspun strands to an electrostatic charge. This helps to keep the web pinned to the transporting belt. As such, it is desirable that the spin agent have an acceptable suitable dielectric strength. Therefore, in a commercial operation the maximum throughput rate obtainable with dichloromethane as a spin agent would be limited. To obtain high throughput rates, it would be necessary to add a co-spin agent which has a high dielectric strength such as DCE (about 105 KV/cm) or HCFC-122 (about 110 KV/cm) so that good electrostatic charging and pinning of the webs onto the belt could be achieved. FIG. 6 shows cloud point curves for 2GT in 100% dichloromethane and for 2GT in 85%dichloromethane primary spin agent with 15% DCE co-spin agent. The figure illustrates, for example, that the use of DCE as a co-spin agent provides conditions suitable to flash spin good plexifilamentary film fibrils.
Also, poly(1,4-butylene terephthalate)(4GT polyester) has been found useful. Solvents suitable for making plexifilamentary strands of 4GT include HCFC-122 and DCE. DCE and HCFC-122 are good spin agents for both 3GT and 4GT and well fibrillated plexifilaments can be obtained by flash spinning at a temperature range of 200-240° C. This is shown by the cloud point curves in FIGS. 3-4, which show various amounts of 3GT and 4GT in HCFC-122.
The polyester is present in the solvent at 5-30 weight percent based on the total weight of the spin fluid when plexifilamentary fibers are prepared. The term spin fluid as used herein means the solution comprising the fiber-forming polymer, the primary spin agent, any co-spin agent that may be present, plus any additives that may be present. The term spin mixture may also be used to refer to the spin fluid. Unless noted otherwise, the term weight percent (wgt. %) as used herein refers to the percentage by weight based on the total weight of the spin fluid. The polyester can also be present in the solvent in the range of 10 to 25 wgt. %. Further, the polyester can be present in the solvent in the range of 20 to 25 wgt. %.
The term “cloud-point pressure” as used herein, means the pressure at which a single phase liquid solution starts to phase separate into a polymer-rich/spin agent-rich two-phase liquid/liquid dispersion. However, at temperatures above the critical point, there cannot be any liquid phase present and therefore a single phase supercritical solution phase separates into a polymer-rich/spin agent-rich, two-phase gaseous dispersion.
Certain blended polymer plexifilamentary fibers have been flash spun from a polymer 15 and a solvent solution using a process as generally described in U.S. Pat. No. 3,227,794 to Anderson et al. The apparatus used for solution flash spinning in the examples below was a laboratory scale batch spinning unit that is described below and also in U.S. Pat. No. 5,147,586 to Shin et al. It is anticipated that in commercial applications, certain of the blended polymer plexifilaments of the invention could be solution flash spun using the apparatus disclosed in U.S. Pat. No. 3,851,023 to Brethauer et al.
It has been found that certain polyesters, e.g., 3GT and also 2GT and 4GT, can be blended with polyethylene and flash spun using a suitable spin agent to obtain plexifilamentary fibers having desirable properties. To obtain the desired 3GT blends, a mixture of 5 to 95 wgt. % 3GT and 95 to 5 wgt. % high-density polyethylene, based on the total weight of the blend mixture was used. The 3GT blends of polyester plus polyethylene were flashspun in dichloromethane spin agent and consisted of 20 wgt. % of the spin fluid. Also, blends were made from polyethylene with either 2GT or with 4GT, wherein the polyester and the polyethylene were present in the blend at about 50/50 (wgt/wgt). These blends of the polyester plus polyethylene were flashspun in dichloroethylene spin agent and consisted of about 20 wgt. % of the spin fluid. Either high density or low density polyethylene could be used with the subject blends. It is known that 2GT is practically insoluble in DCE, e.g. the cloud point pressure would be in excess of 4500 psig. Also, 4GT is not particularly soluble in DCE, e.g. the cloud point pressure would be in excess of 2500 psig. As such, it is surprising that well-fibrillated plexifilaments of 2GT or 4GT blended with polyethylene can be obtained with DCE as a spin agent.
Microcellular and ultramicrocellular foams can be obtained by flash spinning and are usually prepared at relatively high polymer concentrations in the spinning solution, i.e., at east 40 wgt. % of 2GT, 3GT or 4GT polyester. The microcellular and ultramicrocellular foams of this invention have densities between 0.005 and 0.50 gm/cc. The cells for microcellular foams are generally of a polyhedral shape and their average cell size is less than about 300 micrometers, preferably less than about 150 micrometers. The cell walls are typically less than about 3 micrometers, preferably less than about 2 micrometers in thickness. The ultramicrocellular foams are typically more uniform and of a smaller size. Typical ultramicrocellular foams have an average cell size of less than 50 micrometers and the cell wall thickness is less than 1 micrometer. Hereafter, for the sake of convenience the term foams is meant to include both microcellular and ultramicrocellular foams.
It is known that 2GT polyester does not typically form acceptable plexifilamentary strands, except with dichloromethane as the spin agent. With other spin agents, such as DCE or HCFC-122, the spin pressure would be too high, e.g., in excess of 5000 psi, when less than 30 wgt. % polymer concentration is used to obtain plexifilaments. However, it has been found that at the higher concentrations of polyester (typically 40 wgt. % or greater) used for flash spinning foams, 2GT is sufficiently soluble in other solvents, such as DCE and HCFC-122, to provide spin fluids which can be flash spun to make foams as shown in FIGS. 2-4. FIG. 1 shows that 2GT in dichloromethane exhibits an acceptable range of cloud points, irrespective of the amount of 2GT.
Foams may be formed at relatively low spinning temperatures; and typical spinning pressures used are above the cloud point pressure. However, foam fibers may be obtained rather than plexifilaments even at spinning pressures slightly below the cloud point pressure of the solution. Spin agents and co-spin agents are the same as those noted above for the plexifilamentary, film-fibril materials. Nucleating agents, such as fumed silica and kaolin, can be added to the spin mixture to facilitate spin agent flashing and to obtain uniform, small-sized cells.
Foams can be obtained in a collapsed form or in a fully or partially inflated form. For many polymer/solvent systems, foams tend to collapse after exiting the spinning orifice as the solvent vapor condenses inside the cells and/or diffuses out of the cells. To obtain low density inflated foams, inflating agents having low boiling temperatures are usually added to the spin fluid. Suitable inflating agents that can be used include partially halogenated hydrocarbons, such as, hydrochlorofluorocarbons and hydrofluorocarbons; perfluorocarbons; and hydrofluoroethers. Other organic solvents and gases having low boiling temperatures can be used. When very low density foams (0.0005-0.1 g/cm 3 ) are desired, as-spun foams can be post-inflated using the procedures described in Blades, Parrish and Bonner.
Foam fibers are normally spun from a round cross section spin orifice. However, an annular die similar to the ones used for blown films can be used to make foam sheets.
It should be noted that the 2GT, 3GT, and 4GT polymers herein are intended to include copolymers with recurring units of up to about 15% monomer as well as homopolymers whether used for making foams or plexifilaments. Moreover, it has been found that the addition of monomers to a homopolymer can decrease the cloud point pressure such that the resulting copolymer can be flash spun at a lower temperature and pressure. This is demonstrated in FIG. 5 which presents cloud point curves for various amounts of monomers added to 3GT. The comonomers added were dimethyl isophathalate (DMI), dodecanedioic acid (DDDA) and adipic acid (AA).
EXAMPLES
Test Methods
In the description above and in the non-limiting examples that follow, the following test methods were employed to determine various reported characteristics and properties. ASTM refers to the American Society of Testing Materials.
The intrinsic viscosity of the 2GT and 3GT polymer samples was measured at 19° C. using a Viscotek Forced Flow Viscometer Model Y-900. The samples were dissolved in 50/50 (wt/wt) trifluoroacetic acid/dichloromethane at room temperature at a polymer concentration of 0.4 g/dl. The viscosity data (dl/g) reported represents correlated intrinsic viscosity values in 60/40 (wt/wt) phenol/1,1,2,2-tetrachloroethane following ASTM D-4603-96.
The denier of the strand was determined from the weight of a 15 cm sample length of strand under a predetermined load.
Tenacity and elongation of the flashspun strand were determined with an Instron tensile-testing machine. The strands were conditioned and tested at 70° F. (21° C.) and 65% relative humidity. The strands were then twisted to 10 turns per inch (about 4 turns per centimeter) and mounted in the jaws of the Instron Tester. A two-inch (5.08 cm) gauge length was used with an initial elongation rate of 4 inches per minute (10.2 centimeters per minute). The tenacity at break is recorded in grams per denier (gpd). The elongation at break is recorded as a percentage of the two-inch gauge length of the sample. Modulus corresponds to the slope of the stress/strain curve and is expressed in units of gpd.
The surface area of the plexifilamentary film-fibril strand product is another measure of the degree and fineness of fibrillation of the flashspun product. Surface area is measured by the BET nitrogen absorption method of S. Brunauer, P. H. Emmett and E. Teller, J. Am. Chem. Soc., V. 60 p 309-319 (1938) and is reported as m 2 /g.
Test Apparatus for Examples 1-41
The apparatus used in the Examples is the spinning apparatus described in U.S. Pat. No. 5,147,586. The apparatus consists of two high-pressure cylindrical chambers, each equipped with a piston which is adapted to apply pressure to the contents of the chamber. The cylinders have an inside diameter of 1.0 inch (2.54 cm) and each has an internal capacity of 50 cubic centimeters. The cylinders are connected to each other at one end through a {fraction (3/32)} inch (0.23 cm) diameter channel and a mixing chamber containing a series of fine mesh screens that act as a static mixer. Mixing is accomplished by forcing the contents of the vessel back and forth between the two cylinders through the static mixer. The pistons are driven by high-pressure water supplied by a hydraulic system. A spinneret assembly with a quick-acting means for opening the orifice is attached to the channel through a tee. The spinneret assembly consists of a lead hole of 0.25 inch (0.63 cm) diameter and about 2.0 inch (5.08 cm) length, and a spinneret orifice with a length and a diameter each measuring 30 mils (0.762 mm). A spinneret orifice with a length and a diameter each measuring 30 mils (0.762 mm) was used for all the examples, except Examples 17 and 19. In Example 17, the spinneret orifice had a length and a diameter each measuring 15 mils (0.381 mm). In Example 19, the spinneret orifice had a length of 30 mils (0.762 mm) and a diameter of 15 mils (0.381 mm).
In the tests reported in Examples 1-20 and 41, the apparatus described above was charged with pellets of a polyester and a spin agent. For Examples 21-40, the apparatus was also charged with high density polyethylene, in addition to the polyester. The high-pressure water was used to drive the pistons to generate a mixing pressure of between 1500 and 4500 psig (10,239-30,717 kPa). The polymer and spin agent were then heated to mixing temperature and held at that temperature for a specified period of time during which the pistons were used to alternately establish a differential pressure of about 50 psi (345 kPa) or higher between the two cylinders so as to repeatedly force the polymer and spin agent through the mixing channel from one cylinder to the other to provide mixing and to effect formation of a spin mixture. The spin mixture temperature was then raised to the final spin temperature, and held there for a time sufficient to equilibrate the temperature, during which time mixing was continued. However, the time was kept as short as possible at the subject temperatures to avoid degradation of the polymer or the spin agent. It should be noted that when a range of temperatures is given for a particular example, the mixing time was measured from the starting temperature indicated until the solution was flash spun. In order to simulate a pressure letdown chamber, the pressure of the spin mixture was reduced to a desired spinning pressure just prior to spinning. This was accomplished by opening a valve between the spin cell and a much larger tank of high-pressure water (“the accumulator”) held at the desired spinning pressure. The spinneret orifice was opened as soon as possible (usually about one to two seconds) after the opening of the valve between the spin cell and the accumulator. This period was intended to simulate the residence time in the letdown chamber of a large-scale spinning apparatus. The resultant flashspun product was collected in a stainless steel open mesh screen basket. The pressure recorded during spinning just before the spinneret was entered as the spin pressure. The pressure was recorded using a computer.
It is noted that pressures may be expressed as psig (pounds per square inch gage) which is approximately 15 psi less than psia (pounds per square inch absolute). The unit psi is considered the same as psia. For converting to SI units, 1 psi=6.9 kPa. When an item of data was not measured or was not available, it is noted in the tables as N.M. or N.A., respectively.
Particularly in the tables that follow, the amount of primary spin agent and co-spin agent may be expressed at times as their percentage by weight of the combined weight of the primary spin agent and the co-spin agent. Weston 619F, a diphosphite thermal stabilizer from GE Specialty Chemicals, was added at 0.1 weight percent, based on total spin agent for each of the following plexifilamentary Examples 1-9 and 19-41. The stabilizer was not added to the foam Examples 10-18 unless so noted. Other ingredients were added as noted.
Examples 1-3
In Examples 1-3, 3GT was flash spun using either HCFC-122 or a mixture of HCFC-122 and dichloromethane as the spin agent. The 3GT polymer was prepared from terephthalic acid and 1,3-propanediol with TYZOR®TPT (tetraisopropyl titanate) as the polycondensation catalyst, using methods known in the art. TYZOR®TPT is available from DuPont. The as-prepared polymer had an intrinsic viscosity of 0.76 dl/g. The polymer was solid phase polymerized at 205° C. under nitrogen to obtain an instrinsic viscosity of 1.53 dl/g.
In Example 1, a spin mixture was prepared containing 20 weight percent of 3GT polymer in HCFC-122 spin agent. Cab-o-sil N70-TS colloidal silica was added as a nucleating agent at 1.0 weight percent, based on polymer weight.
In Examples 2-3, the spin mixture contained 15 weight percent 3GT, based on total spin mixture weight, in a 50/50 (wgt/wgt) mixture of HCFC-122 and dichloromethane.
Plexifilamentary fibers were obtained by flash spinning the spin mixtures using the conditions given in Table 1 below. In Example 3, a spin tunnel having a diameter of 200 mils (0.51 cm) and a length of 100 mils (0.25 cm) was used outside of the spinneret. Mechanical properties of the plexifilaments are also reported in Table 1.
Examples 4-5
In Examples 4 and 5, plexifilaments were flash spun from a spin mixture containing 20 weight percent 3GT, based on total weight of the spin mixture, and a spin agent which was either trans-1,2-dichloroethylene (DCE) (Example 4) or a 50/50 (w/w) mixture of DCE and dichloromethane (Example 5). Cab-o-sil N70-TS fumed silica nucleating agent (Cabot Corporation, Boston, Mass.) was also added to each of the spin mixtures at 1.0 weight percent, based on polymer.
The 3GT polymer used in Example 4 had an intrinsic viscosity of 1.70 dl/g and was obtained by solid phase polymerization (205° C., nitrogen) of the as-prepared polymer (0.76 dl/g intrinsic viscosity) described in Examples 1-3 and had an intrinsic viscosity of 1.70 dl/g. The 3GT polymer used in Example 5 was also solid phase polymerized (205° C., nitrogen) from the same starting polymer and had an intrinsic viscosity of 1.87 dl/g.
Plexifilaments having a BET surface area of 4.1 m 2 /g for Example 4 and a surface area of 2.0 m 2 /g for Example 5 were obtained by flash spinning the spin mixtures using the conditions given in Table 1 below. Plexifilament mechanical properties are also reported in Table 1.
Example 6
This example demonstrates flash spinning of 3GT using dichloromethane as the spin agent. A spin mixture was prepared containing 25 weight percent of the 3GT polymer described in Examples 1-3.
Plexifilaments having a BET surface area of 9.23 m 2 /g were obtained by flash spinning the spin mixtures using the conditions given in Table 1 below. Plexifilament mechanical properties are also reported in Table 1.
TABLE 1
3GT Plexifilamentary Fibers
Fiber Properties
Mixing
Spinning
@ 10 tpi
Ex.
Temp
Back P
ΔP
Accum P
Spin P
Temp
gms
Ten
E
Modulus
No.
Solvent
(° C.)
min
(psig)
(psig)
(psig)
(psig)
(° C.)
load
Den
(gpd)
(%)
(gpd)
1
HCFC-122
170-
32
4500
150
3600
3300
211
40
1064
0.46
82
2.03
210
2
50/50
180-
17
3200
250
2400
2250
221
50
580
0.47
100
1.23
HCFC-122/
220
CH 2 Cl 2
3
50/50
180-
17
3600
250
2950
2800
240
50
542
0.49
68
2.02
HCFC-122/
243
CH 2 Cl 2
4
DCE
190
7
3900
350
3250
2950
196
100
900
0.78
85
nm
5
50/50
190
6
2000
200
1200
1100
190
100
489
1.03
86
2.40
DCE/CH 2 Cl 2
6
CH 2 Cl 2
145-
25
2800
200
1700
1600
240
100
369
0.94
81
3.27
240
Example 7
This example demonstrates flash spinning of 4GT plexifilaments using HCFC-122 as the spin agent. The 4GT polymer used was CRASTIN® 6129 4GT, obtained from DuPont. CRASTIN® 4GT has a melt flow rate of 9 g/10 min measured by standard techniques at a temperature of 250° C. with a 2.16 kg weight, and has a melting point of 225° C. The spin mixture contained 15 weight percent 4GT polymer, based on total weight of the spin mixture, in HCFC-122 spin agent.
Plexifilaments were obtained by flash spinning the spin mixtures using the conditions given in Table 2 below. Plexifilament mechanical properties are also reported in Table 2.
Examples 8-9
In Examples 8 and 9, plexifilaments were flash spun from a spin mixture containing 20 weight percent of 4GT as described in Example 7 in a spin agent of DCE.
Plexifilaments were obtained by flash spinning the spin mixtures using the conditions given in Table 2 below. Plexifilament mechanical properties are also reported in Table 2.
TABLE 2
3GT Plexifilamentary Fibers
Fiber Properties
Mixing
Spinning
@ 10 tpi
Ex.
Temp
Back P
ΔP
Accum P
Spin P
Temp
gms
Ten
E
Modulus
No.
Solvent
(° C.)
min
(psig)
(psig)
(psig)
(psig)
(° C.)
load
Den
(gpd)
(%)
(gpd)
7
HCFC-122
190-
5
4000
600
3100
2975
231
100
505
0.99
91
4.23
230
8
DCE
160-
15
3200
250
2475
2300
200
20
274
0.80
49
nm
200
9
DCE
160-
17
3600
250
2850
2700
219
100
359
1.09
77
3.99
223
Examples 10-12
These examples demonstrate flash spinning of 3GT foam. The 3GT polymer as described in Examples 1-3, having an intrinsic viscosity of 1.53 dl/g, was used to prepare spin mixtures containing 50 weight percent 3GT. Cab-o-Sil N70-TS colloidal silica was added to each spin mixture at 1.0 weight percent, based on polymer. The spin agents used were dichloromethane, DCE and HCFC-122 for Examples 10, 11, and 12, respectively.
The spin mixtures were flash spun using the conditions shown in Table 3 to obtain acceptable foam fibers.
TABLE 3
Flash Spinning Conditions for 3GT Foam
Mixing
Spinning
Temp
Back P
ΔP
Accum P
Temp
Example
Solvent
(° C.)
Min
(psig)
(psig)
(psig)
Spin P (psig)
(° C.)
10
CH 2 Cl 2
190
30
1500
800
800
450
191
11
DCE
190
35
1500
1000
775
325
189
12
HCFC-122
205
30
1500
1000
770
260-110
203
Examples 13-16
These examples demonstrate flash spinning of 4GT foams. The 4GT as described in Example 7, was used to prepare spin mixtures containing 50 weight percent 4GT. The spin agents used in Examples 13 and 14 were dichloromethane and DCE, respectively. HCFC-122 was used as the spin agent for Examples 15 and 16. Cab-o-sil N70-TS fumed silica (Cabot Corporation, Boston, Mass.) was added to each spin mixture at 1.0 weight percent, based on polymer. The spin mixtures were flash spun using the conditions shown in Table 4 to obtain acceptable foam fibers.
TABLE 4
Flash Spinning Conditions for 4GT Foam
Mixing
Spinning
Temp
Back P
ΔP
Accum P
Temp
Example
Solvent
(° C.)
Min
(psig)
(psig)
(psig)
Spin P (psig)
(° C.)
13
CH 2 Cl 2
190
30
1500
800
800
350
191
14
DCE
190
20
1500
500
800
275-125
190
15
HCFC-122
190
34
1500
1500
800
250-150
185
16
HCFC-122
190
34
1500
1500
800
150-350
185
Examples 17-18
These examples demonstrate flash spinning of 2GT foams. The 2GT was obtained from DuPont. The 2GT polymer, having an intrinsic viscosity of 0.67 dl/g was solid phase polymerized by heating in nitrogen for 16 hours at 235° C. The solid phase polymerized polymer used in Examples 17 and 18 had an intrinsic viscosity of 1.02 dl/g.
The spin agents used in Examples 17 and 18 were DCE and HCFC-122, respectively. Spin mixtures were prepared containing 50 weight percent 2GT. Weston 619F thermal stabilizer was added to the spin mixture of Example 18 at 0.1 weight percent, based on total spin agent. The spin mixtures were flash spun using the conditions shown in Table 5 to obtain acceptable foam fibers.
TABLE 5
Flash Spinning Conditions for 2GT Foam
Mixing
Spinning
Temp
Back P
ΔP
Accum P
Temp
Example
Solvent
(° C.)
Min
(psig)
(psig)
(psig)
Spin P (psig)
(° C.)
10
DCE
190-240
27
2000
200
1200
900
190
18
HCFC-122
210-255
29
2000
400
1200
800-1125
210
Example 19
This example demonstrates flash spinning of a 3GT copolymer containing isophthalate units. The copolymer was prepared using methods known in the art by polymerizing 1,3-propanediol, dimethyl terephthalate, and dimethyl isophthalate using TYZOR®TPT tetraisopropyl titanate as the polycondensation catalyst. The dimethyl isophthalate was added in an amount equal to 5 mole percent of the total dimethyl terephthalate and dimethyl isophthalate. The as-prepared copolymer (intrinsic viscosity of 0.72 dl/g) was solid phase polymerized under nitrogen at 205° C. to obtain an intrinsic viscosity of 1.69 dl/g.
The spin mixture was prepared containing 20 weight percent of the above-described copolymer in HCFC-122 spin agent. The mixing temperature was 210° C., and the mixing time was 10 minutes at a back pressure of 4000 psig and a pressure differential of 250 psig. The solution was flash spun at 211° C. and a spin pressure of about 3000 psig with an accumulator pressure of 3275 psig. The resulting plexifilaments had a denier of 1032 under 100 grams load, modulus of 2.36 grams per denier, tenacity of 1.17 grams per denier, and a percent elongation of 104%.
Example 20
This example demonstrates flash spinning of a 3GT copolymer containing isophthalate units using dichloromethane as the spin agent. The copolymer was prepared using methods known in the art with dimethyl isophthalate added in an amount equal to 5 mole percent of the total dimethyl terephthalate and dimethyl isophthalate. The copolymer was solid phase polymerized under nitrogen to obtain an intrinsic viscosity of 1.49 dl/g.
A spin mixture was prepared containing 20 weight percent of the 3GT copolymer in dichloromethane spin agent. The mixing temperature was 240° C., and the mixing time was 7 minutes at a back pressure of 3000 psig and a pressure differential of 200 psig. The solution was flash spun at a temperature of 241° C. and a spin pressure of 1650 psig with an accumulator pressure of 1800 psig. The resulting plexifilaments had a denier of 584 under 100 grams load, modulus of 4.24 grams per denier, tenacity of 0.89 grams per denier, and a percent elongation of 102%.
Examples 21-23
These examples demonstrate flash spinning of a polymer blend of 3GT and high density polyethylene using dichloromethane as the spin agent. In each example the dichloromethane was present at 80 wgt. % of the spin mixture and the 3GT/polyethylene blend was present at about 20 wgt. %.
The 3GT polymer described in Examples 1-3, having an intrinsic viscosity of 1.53 dl/g was used in these examples. High density polyethylene having a melt index of 0.75 g/10 min (measured according to ASTM D1238 at 190° C. and 2.16 kg load) and a density of 0.95 g/cm 3 was mixed with 3GT and the dichloromethane spin agent to prepare the spin mixtures. The polyethylene was Alathon®, obtained from Equistar Chemicals LP of Houston, Tex.
The spin mixture of Example 21 contained 30 weight percent 3GT and 70 weight percent high density polyethylene, based on the total weight of the blend.
The spin mixture of Example 22 contained 50 weight percent 3GT and 50 weight percent high density polyethylene, based on the total weight of the blend.
The spin mixture of Example 23 contained 70 weight percent 3GT and 30 weight percent high density polyethylene, based on the total weight of the blend.
The mixing temperature was 225° C., and the mixing time was 20 minutes at a back pressure of 2500 psig and a pressure differential of 250 psig. Spinning conditions and plexifilament properties are given in Table 6.
TABLE 6
Flash Spinning Conditions for 3GT/Polyethylene Blends
Spinning
Fiber Properties
Accum
@ 10 tpi
Ex.
P
Spin P
Temp
gms
Ten
E
Modulus
No.
(psig)
(psig)
(° C.)
load
Den
(gpd)
(%)
(gpd)
21
1100
850
223
50
294
3.46
119
3.94
22
900
750
227
50
221
3.51
107
4.4
23
1100
975
224
50
271
1.95
116
2.66
Examples 24-40
These examples demonstrate flash spinning blends of 2GT, 3GT or 4GT and high density polyethylene using dichloroethylene as the spin agent. High density polyethylene having a melt index of 0.75 g/10 min (measured according to ASTM D1238 at 190° C. and 2.16 kg load) and a density of 0.95 g/cm 3 was mixed with polyester and the dichloroethylene spin agent to prepare the spin mixtures. The polyethylene was Alathon®, obtained from Equistar Chemicals LP of Houston, Tex. In each of the examples, the polyester and the polyethylene were present in the blend at 50/50 (wgt/wgt). In each of the examples the dichloroethylene was present at about 80 wgt. % of the total spin mixture and the polyester/polyethylene blend was present at about 20 wgt. %.
The 2GT was as described in Examples 17-18. The 3GT copolymer was described in Example 20 was used in Examples 30-32. The 4GT polymer was CRASTIN® 6129 4GT as first described in Example 7.
Mixing and spinning conditions and resultant plexifilament properties are presented in Table 7, below.
Example 41
The spin mixture was prepared containing 25 weight percent of 2GT in a spin agent of 85/15 (wgt/wgt) dichloromethane/DCE. The 2GT was solid-phase polymerized Crystar® 5005sc 656 with an intrinsic viscosity of 1.3. Crestar® is a registered trademark of and available from DuPont. Mixing was started at 150° C. and continued for 45 minutes, and then raised to 220° C. for a total mixing time of 67 minutes. The mixing pressure was 3000 psig throughout. The solution was flash spun at 221° C. and a spin pressure of about 1625 psig with an accumulator pressure of 1800 psig. The resulting plexifilaments had a denier of 806 under 40 grams load, modulus of 8.8 grams per denier, tenacity of 0.95 grams per denier, and elongation of 80%.
TABLE 7
Flash Spinning Conditions for 2GT, 3GT and 4GT/Polyethylene Blends
Fiber Properties
Mixing
Spinning
@ 10 tpi
Ex.
Temp
Back P
ΔP
Accum P
Spin P
Temp
gms
Ten
E
Modulus
No.
Blend
(° C.)
min
(psig)
(psig)
(psig)
(psig)
(° C.)
load
Den
(gpd)
(%)
(gpd)
24
2GT/PE
220
5
2500
600
1400
1350
220
100
314
2.45
107
8.24
25
2GT/PE
210
5
2500
600
1400
1250
210
40
581
1.46
89
6.77
26
2GT/PE
210
10
2500
600
950
750
211
100
410
3.04
110
13.3
27
2GT/PE
210
10
2500
700
1700
1450
211
100
478
3.04
125
8
28
2GT/PE
210
10
2500
700
1550
1250
210
100
440
2.92
118
8.75
29
2GT/PE
210
10
2500
600
1900
1600
210
100
420
2.44
111
2.26
30
3GT*/PE
230
10
2500
600
1100
975
231
40
202
2.15
96
7.12
31
3GT*/PE
220
5
2500
700
1100
700
219
40
682
0.86
261
2.1
32
3GT/PE
210
10
2500
600
1100
750
211
40
526
1.03
103
2.91
33
4GT/PE
230
10
2500
700
1100
950
233
40
215
2.11
64
6.7
34
4GT/PE
210
10
2500
700
950
NA
211
40
317
1.87
99
6.23
35
4GT/PE
210
10
2500
700
1400
1250
212
100
327
3.53
101
14.7
36
4GT/PE
210
10
2500
700
1700
1300
210
40
654
2.22
125
6.69
37
4GT/PE
210
10
2500
600
1300
1000
210
40
540
1.92
111
4.89
38
4GT/PE
210
10
2500
700
1500
750
209
40
546
2.31
120
6.24
39
4GT/PE
220
5
2500
700
1100
NA
220
100
284
3.53
111
8.16
40
4GT/PE
210
10
2500
700
1100
750
209
40
413
2.15
109
5.80
*These examples included 5 mole % dimethyl isophthalate.
|
A process for producing plexifilamentary or foam products by flash spinning in selected spin agents a polymer from the group consisting of poly (1,3-propylene terephthalate), poly (1,4-butylene terephthalate), and poly(ethylene terephthalate), including their copolymers in which the spin agents have minimal or no ozone-depleting properties.
| 3
|
BACKGROUND OF THE INVENTION
The present invention concerns an apparatus, for deploying an object or a load on the seabed, the object or the load being coupled to hoisting means, such as a hoisting wire in order to enable the object or the load to be lowered to the seabed from a vessel, the apparatus comprising a body having means for releasably securing the object or the load to the body and propulsion means for moving the body when submerged without using guide wires.
The present invention concerns a guiding, controlling and positioning system, used during the deployment and/or recovery of loads (packages) up to ±1000 tons on the sea bed, at great depth. Structurally, the system comprises a main module and a smaller counter module joined to each other by a frame.
Due to its functions, the system's frame can be clamped directly to a load or alternatively to any hoisting means, hence securing the loads (packages) to be deployed. Equally, the system can release the said loads at any chosen time. The system also comprises propulsion- and moment control means, enabling it to control the behaviour of the load while being deployed through the entire water column.
DESCRIPTION OF THE RELATED ART
Since oil and gas at sea can also be exploited by means of floating production platforms, such exploitation of oil- and gas fields requires that several heavy objects be deployed on the seabed, moreover, these objects have to be positioned on the seabed with a relatively high accuracy.
Due to the fact that nowadays oil exploration is being conducted at greater depth, achieving the required accuracy is increasingly more difficult. To achieve such an accuracy according to traditional methods, usually a crane vessel is used. The loads are lowered to the seabed by way of auxiliary, control wires either rigged to the same vessel and/or one or more auxiliary installation supports.
Using such methods is extremely expensive. The latter have been devised in order to control turning moments in installation aids induced primarily by changing current profiles but also by non-torque balanced wire ropes. By the same token, the aim is also to guide the load towards its final heading and within its required target area.
The object of the invention therefore is to devise a system and appropriate method by which loads (packages) will be deployed, controlled and positioned accurately on the seabed in a cheaper and faster manner than the conventional installation approaches.
SUMMARY OF THE INVENTION
This object, according to the present invention, is achieved. Thereby it is possible that the apparatus is provided with first and second propulsion means secured to the body, the first and second propulsion means being positioned at opposite sides of the means for releasebly securing the object or the load.
With this measures an anti-twist device is provided. Moreover with the thrusters the position of the apparatus, and so the load, with respect to the load can be adjusted and controlled.
According to the invention it is possible that, the apparatus is provided with means to adjust the distance between the first and second propulsion means.
Also it is possible that the first propulsion means are positioned in a first-module and that the second propulsion means are positioned in a second-module.
According to the present invention and in order to eradicate these traditional costs, the system is provided with a set of four thrusters working in pairs, each having a dedicated function, namely; a torque control function and a translation function.
These thrusters are mounted on each side of the system's frame, two by two, in such a way as to achieve the above mentioned torque control by dedicating both lower thrusters to this torque control function and to achieve the translation control by dedicating both upper thrusters to this translation function.
Moreover, the second or counter module can move horizontally over a section of the frame, in order to improve torque control and to minimize stress cycles in the overall structure. It is understood that this frame comprises a hydraulically activated clamping system, ending in dedicated clamping adapters, provided with a high friction medium.
According to the invention it further possible that the propulsion means are provided in the form of thrusters.
As stated above it is possible that the first propulsion means are positioned in a first-module and that the second propulsion means are positioned in a second-module. The second-module could be attached to an arm, the length of the arm being adjustable.
According to a preferred embodiment of the invention, the first module is secured detachably to the apparatus.
According to the invention it is possible that the means for releasably securing a load comprises hydraulic jacks. Moreover the means for releasably securing a load in the apparatus could be provided with purposed designed adapters, the adapters being covered with a high friction medium.
In order to be able to achieve the required accuracy during deployments, it is preferred that the apparatus is provided with means adapted to transmit information in the direction of an object on the seabed, and with means to receive a reflection of the signal transmitted to the object, and a processor to compute the reflected information to establish the position of the apparatus with respect to the object. Also, the apparatus could be provided with a distance log.
The means for transmitting information could include sonar equipment, such as High Resolution Sonar Equipment. When the position of the load to be deployed with respect to the object on the seabed is determined, using the sonar equipment, the positioning of the load could be finalized using the distance log. So, it is possible to dissociate this final positioning activity from the surface support.
According to the present invention not only the apparatus but also a method for deploying an object or a load at the seabed is provided, the method being characterized in that the method comprises the steps of:
moving the object or load in the direction of the seabed, by means of a first hoisting wire,
exerting a force on the object or load, or on the first hoisting wire, approximately at the bottom end thereof by means of a second hoisting wire and
manipulating the position of the object or the load by means of an apparatus according to one of the preceding claims, the apparatus being attached close to the object or the load. Moreover it is possible that during the deployment of the object or the load, the object or the load is lifted at least partially by means of the secondary hoisting wire.
According to the invention it is possible that during the deployment of the object or the load, the positioning of the apparatus is accomplished using a differential global positioning system (DGPS) navigation system, interfaced with a Hydroacoustic Positioning Reference (HPR) system, a Doppler device and a Fibre Optic Gyro. Moreover it is possible that the apparatus transmits information in the direction of an object on the seabed, in that the apparatus receives a reflection of the signal transmitted to the object, and the reflected information is used to establish the position of the apparatus with respect to the object, and in that the positioning of the load is accomplished by means of a distance log.
According to the present invention it is also possible that
the first hoisting wire is paid out until the first hoisting wire is a least partially lying on the seabed,
hoisting the object or the load and a part of the first hoisting wire by means of the secondary hoisting wire, and
manipulating the position of the object or the load by means of the apparatus.
BRIEF DESCRIPTION OF THE DRAWINGS
Below, the invention is explained in details with reference being made to the drawings.
FIG. 1 shows a schematic overview of a FPSO (floating, production, storage and offloading system) dedicated to offshore petrochemical recoveries.
FIG. 2 shows a crane vessel according to the prior art and displaying a load rigged to the crane block with relatively long wire ropes whereby it is possible to see that the control of the load is virtually impossible at great depth.
FIG. 3 shows a crane vessel according to the prior art and displaying a load rigged not only to the vessel's crane block, but also to auxiliary wire ropes on either side of the vessel as well as to a secondary surface support tow wire in order to exert a certain amount of control over the load.
FIG. 4 shows a crane vessel and a system for deploying and/or recovering a load to and/or from the seabed according to the present invention.
FIG. 5 shows a detail overview of a possible embodiment of the system while engaged in the activities listed in FIG. 4 .
FIG. 6 shows the system viewed in accordance with FIG. 5 from above.
FIG. 7 shows a detail of the system (adaptation shoes for a pipe and/or crane block) according to FIG. 5 .
FIGS. 8 a , 8 b show a cross-sectional view of the main module of the system hardware equipment required in order to conduct deploying and/or recovering activities according to the present invention.
FIGS. 9 & 10 show a possible use of the main module of the system as stand-alone equipment during the deployment of an anchor and anchor chain according to the present invention.
FIG. 11 shows a purpose designed crane block to be used in conjunction with the system according to the present invention.
FIG. 12 shows an embodiment of the system's main module being used for deployment and installation of a spool piece diver-less at great depth according to the present invention.
FIG. 13 shows the embodiment of the system's main module being used for deploying and docking rigid and/or flexible risers to a riser base in a diver-less mode at great depth.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With FIG. 1 the layout presents a FPSO 1 with her swivel production stack 11 from which risers 2 depart, said risers connecting to their riser bases 3 at the seabed. During her production lifetime, it is tantamount for the FPSO to remain within an allowable dynamic excursion range and therefor the FPSO 1 is moored to the seabed 4 by means of mooring legs 5 which are held by anchors 6 .
Exploitation of oil or gas according to FIG. 1, by means of a production vessel 1 , requires that several relatively heavy objects be positioned at the seabed 4 with a relatively high accuracy.
To secure an appropriate and safe anchoring by means of the mooring legs 5 , it is required that these mooring legs 5 have approximately the same length. In practice for this application anchors can be used with a weight of 50 ton and more, which are placed at the seabed 4 with an accuracy to within several meters. Moreover not only is the anchor 6 itself very heavy, but the mooring leg attached to the anchor 6 has a weight that equals several times the weight of the anchor 6 itself.
Also for other objects like the “templates”, “gravity riser bases”, “production manifolds” etceteras applies that these objects have to be put on the seabed 4 with relatively high accuracy.
The objects that are shown in FIG. 1 that are required for exploiting the oil and gas at sea and that have to be put on a seabed, are not only very heavy, but very expensive as well.
FIG. 2 shows a vessel 20 , according to the prior art, having hoisting means thereon, like a crane 21 . The crane 21 is provided with a hoisting wire 22 , by means whereof an object or a load 4 can be put on the seabed 5 . In order to position the load 23 it is necessary to move the surface support together with the crane 21 .
The result will be that, at one given time the load 23 inertia will be overcome but due to the load 23 acceleration, an uncontrollable situation will occur, whereby the target area will be overshot. Because of the fact that the hoisting wire 22 and the load 4 are susceptible to influences like the current, the load will not move straight downward, when the hoisting wire is being lowered. Also the heave of the vessel, the rolling of the vessel etc. will have a negative influence on the accuracy that can be achieved.
In FIG. 3 a possible solution is represented according to the prior art, in order to control the position of the load 23 , while lowering the hoist wire 22 . Therefore the load must be secured to an auxiliary wire 31 that is controlled from an auxiliary vessel 30 . Moreover the load 23 with an auxiliary wire 32 can be attached to the vessel 20 .
FIG. 4 shows a crane vessel 40 provided with the apparatus or system for deploying a load 43 on the seabed according to the present invention, the vessel 40 comprises first hoist means, for example a winch 41 , provided with a first hoist wire 42 . By means of this hoist wire 42 a load 43 , for instance a template can be deployed and placed at the bottom of the sea.
As mentioned above, the exploitation of oil- and gasfields using floating production platform requires that several heavy objects must be placed at the seabed, moreover, these objects have to be placed on a seabed with a relatively high accuracy. Because of the fact that nowadays the exploitation has to be done at increasing depths up to 3000 m and more, achieving the required accuracy is getting harder. One of the problems that has to be solved is the fact that the hoist wires can be twisted.
In order to control the position of the load 43 when deploying the load and in order to be able to position the load on the sea bed within the required accuracy, the apparatus or system 50 has been secured to the lifting wire 42 . A preferred embodiment of the system 50 will be described with reference being made to the FIGS. 5, 6 and 7 .
The system 50 is fixed to the end of the lifting wire 42 , for instance to the crane block 100 (FIG. 11 ). Also, the system 50 could be secured directly to the load 43 itself. The system 50 comprises a first or main-module 51 , provided with drive means such as thrusters (FIGS. 5 and 6 ). The system further comprises of a second or counter module 52 . This counter-module 52 also is provided with thrusters. In use the thrusters of the main-module 51 and of the counter-module 52 will be positioned at opposite sides of the lifting wire 42 . The system is coupled with the vessel 40 by means of a second lifting wire 45 , which can be operated using second hoist means, for instance a second winch 44 . The second hoist wire 45 for instance is set overboard by means of an A-frame 49 . The second winch 44 and the secondary hoist wire 45 normally will be lighter than the first hoist means 48 and the primary hoist wire 42 , respectively. The system further is connected to the vessel 40 by means of an umbilical 46 . This umbilical can be attached to the hoist wire 45 or can be lowered from the tertiary winch 47 separately. The electricity wiring for providing power to the system 50 is for instance accommodated in the umbilical. In the system 50 usually means are provided to convert the electrical power into hydraulic power. The hydraulic power consequently will be used for controlling i.a. the thrusters and auxiliary tooling amenities.
The invention avoids the need to use guide wires in positioning and controlling turning of the load by using a set of thrusters linked to a sensor, as disclosed below.
Since lately the work is being done at an increasing depths, the twisting and turning of the long hoist wires 42 is becoming a bigger problem still. Since heavy loads 43 are attached at the underside of the hoist wire 42 , that twisting can impel a relatively large wear on the hoist wires, so severe damage can occur at the hoist wires. This wear can be so severe that a hoist wire 42 will break and the load 43 will be lost. Another problem is that because of the enormous twists in the wires, the wires at the vessel can run out of the sheaves. Because of the fact that the thrusters of the main-module 51 and of the counter-module 52 , respectively, are positioned at opposite sides of the lifting wire 42 , a counter-torque can be exerted at the hoist wire 42 in both directions. In this way by means of the system an anti-twist device is formed. In order to improve the abilities of this anti-twist device, preferably, the distance between the main-module 51 and the counter-module 52 can be altered.
FIG. 5 shows a detailed overview of a possible embodiment of the system 50 for deploying a load on the seabed according to the present invention. FIG. 6 shows the system according to FIG. 5, from above.
The system 50 comprises a main-module 51 , a counter-module 52 and an arm 53 . The arm can be detached from the main-module 51 . That means that the main-module 51 can also be used separately (see FIGS. 9 and 10 ), as a modular system.
The arm 53 is provided with a recess 54 . On opposite sides of this recess 54 two jacks 57 , 58 are provided, at least one of which can be moved relative to the other. In between the end surfaces of these jacks 57 , 58 an object, such as a crane-block 100 , can be clamped. In order to improve the contact between the jacks 57 , 58 and the object, the respective ends of the jacks are accomodated with clamping shoes lined with a friction element 60 , from a high friction material such as dedicated rubber.
As shown in FIG. 5, the system 50 is provided with thrusters 56 . In use those thrusters 56 can be used to position the system relative to the target area. The thrusters 56 can be actuated from a first position mainly inside the system 50 , to a position in which the thrusters projects out of the system 50 .
In FIG. 6 it is shown that there are two positions 61 , 62 on top of the main-module 51 to connect the main module to the second lifting wire 45 and/or to the umbilical 46 . When the main-module 51 is used separately (FIGS. 9 and 10) position 61 can be used. The main-module 61 will be balanced when the module 61 is deployed, both in the air and underwater.
When the system 50 is used, the connection between the vessel 40 and the system 50 will be fixed in position 62 in order to keep the system in balance, both in the air and underwater. To improve the balance of the system, an auxiliary counterweight 55 can be secured to the system 50 .
In use the apparatus 50 will not have any buoyancy. In order to improve the movability of the system under water, the arm 53 is provided with holes 59 , in order to avoid structural damage due to an increasing pressure while being lowered and to ensure quick drainage during the recovery phase.
As mentioned above, it is advantageous when the counter-module 52 can be moved relative to the main-module 51 . This can be accomplished by using jacks 64 a . The mounting of the counter-module 52 on the arm 53 is shown in detail in FIG. 7 .
The operation of the system 50 according to the invention is as follows:
When deploying a load 43 from a vessel 40 to the seabed, the load will be deployed using a hoist wire 42 . In order to control the position of the load while deploying, the system 50 according to the invention will be secured to the crane block 100 , near the bottom end thereof. The thrusters 56 , in the system 50 are remotely operated from the vessel 40 . The system 50 is provided with sensor means, in order to be able to communicate with the vessel 40 . When the load 43 is not moving in the right direction, the position of the load can be adjusted by activating the thrusters 56 in the system 50 in an automated manner. With reference to the invention, positioning is achieved by interfacing several surface and acoustic reference systems via a proprietary software design which involves as a minimum the following combinations while deploying the loads:
DGPS (Differential Global Positioning System)
SSBL-HiPaP (Super Short Base Line)
Doppler Effect and North seeking gyro.
Furthermore with reference to the invention, once the load has reached its intended depth, the positioning thereof it will be finalized by using a High Resolution Sonar Equipment interfaced to a distance log device and at least one fixed object, whereby it will then be possible to dissociate the positioning activities from the surface support, as well as from any other acoustic transponder devices such as LBL (Long Base Line) arrays while accuracy in the order of centimeters will be achieved within a large radius.
It will be appreciated that the apparatus according to the invention operates free of guidelines.
In FIG. 8 a possible construction for the main-module 51 is shown. The module 51 comprises an outer frame 83 and an inner frame (not shown). The inner frame preferably is cylinder-shaped. By connecting the outer frame 83 to the inner frame, a very strong construction can be accomplished. The strength of the construction is necessary in order to avoid premature fatigue in the system.
The module 51 for instance is partly made of high-tensile steel and thereby designed to be used as integral part of the first 42 or second hoist wire 45 . This means that the top side of the module 51 will be connected to a first part of the hoist wire 45 , and that the underside of the module 51 will be connected to a second part of the hoist wire 45 , or the underside of the module 51 will be attached directly to the load. In this way the load on the hoist wire will be transferred through the module 51 .
As mentioned before, the module 51 is provided with means 84 for converting electrical power, delivered through the umbilical 46 , into hydraulic power. These converting means 84 comprising a motor, a pump, a manifold and a hydraulic reservoir. In order to communicate with an operator on a vessel, the module 51 further comprises sensor means and control means. The module 51 is equipped with a camera/sensor junction box 85 and a light junction box 86 . Furthermore the module 51 comprises light-sources 87 , a Pitch/Roll inclinometer sensor 88 , a gyro 89 and sonar equipment 90 .
The module 51 also accommodates a Doppler 91 unit, a Bathy unit 92 and a Pan/Tilt camera 93 . At the underside of the module are fixed a dimlight-unit 94 , an altimeter 95 , a hydrophone 96 and a colour camera with zoom 97 .
As mentioned above the use of the High Resolution Sonar Equipment together with a distance log is important to achieve the required accuracy, once the load has reached its intended depth. The Sonar Equipment will be used to determine the position with respect to at least one object positioned at the seabed. Using the distance log, it will then be possible to dissociate the positioning activities from the surface support, as well as from any other acoustic transponder devices such as LBL (Long Base Line) arrays, while accuracy in the order of centimeters will be achieved within a large radius.
By means of the module 51 the position of the load can be manipulated. Since the weight of the anchor chain 42 , will be lifted by the first hoist means 41 and only a relatively small weight will be carried by the secondary hoist wire 45 , the freedom of movement of the module 1 is relatively high. That means, that despite the enormous weight of both the anchor chain 42 and the load 43 , the load 43 can be placed with a relatively high accuracy at its destination.
With reference to drawings 9 and 10 it is understood that the system can either be used from a crane vessel or from an Anchor Handler Tug whereby in the case of an AHT support, the primary hoisting wire will be used to lower the load 42 to the seabed while the purpose of the secondary wire 45 will be to pick up some of the loads through the system hence creating a “belly” in the primary wire and providing an excursion radius in order to position the load at its intended location, solely using the thrust capacity of the system.
The combination of the secondary hoist wire 45 and a module 51 allows that jobs, such as positioning an anchor 43 , can be executed with a high accuracy, by means of much smaller vessels than presently are being used in the prior art.
In FIG. 9 an anchor 43 is shown provided with an anchor chain 42 . An anchor chain known in the prior art, for instance, has a specific weight of 250 kg per meter. When such a chain is being lowered 2000 meter, the overall weight of the chain is no less than 500 ton. When at the end of the anchor chain an anchor will be attached with a weight of for instance 75-ton, the weight of the anchor itself is only a small part of the overall weight of the sum of the anchor and the chain.
In FIG. 10 the advantages of using the module 51 by itself are shown even more clearly, for instance in case that an anchor 43 is placed at the seabed. In the surroundings of the destination so much anchor chain 42 is being lowered, that the anchor chain 42 rests upon the seabed. Consequently the anchor 42 will be lifted with a relatively small length of anchor chain. By means of the module 51 the anchor can be moved then to the required destination. The length of the anchor chain from the anchor to the seabed 4 thereby determines the radius of action in which the anchor 43 can be positioned.
In FIG. 11 an embodiment of a crane block 100 is shown, that could be used with the system 50 according to the invention.
Because of the fact that the system 50 enables accurate positioning of both the crane block 100 and a load 43 , it is possible to also recover objects from the sea bed with the system. Above the presence of the jacks 57 and 58 is explained. Those jacks 57 and 58 with an alternative crane block 100 could be used to deploy and recover object. The crane block 100 is provided with through holes 101 , at opposite sides of the block 100 . When the crane block is positioned in the recess 54 in the apparatus 50 , the jacks 57 and 58 can be displaced through the holes 101 . When an object, for example a template 103 , is provided with a T-shaped projection, the object can be released and recovered by moving the jacks 57 , 58 through the holes 101 .
In FIG. 12 an embodiment of the module 51 is shown, adapted to be used when deploying a spool piece. The module 51 is provided with a ball-shaped hydraulic rotator 120 , connected to a hydraulic base frame equipped with jacks 122 . By operating the jacks 122 , any position on all planes of the spool piece 123 can be accomplished.
The system 50 according to the invention also could be used for connecting a flexible, riser 131 to a riser base. In order to avoid undue stress in the material of the flexible riser, the system could be provided with a support arm 130 , to provide the lower part of the flexible riser with sufficient rigidity in order to be connected to the riser base.
An advantage of the system 50 and the method according to the present invention is that a reduction of the risks associated with placing the heavy objects is accomplished.
A further important advantage is that the preliminary-design and fabrication of several required parts for the objects can be executed more accurately. The reason therefore being that there is more certainty about the accuracy that will be achieved, during positioning of the objects on the seabed.
In the description above, several times it is mentioned that the present invention relates to positioning of heavy objects on the seabed. It has to be understood that the invention can be used advantageously as well for hoisting or lifting the objects from the seabed.
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A method and an apparatus, for deploying an object or a load on the seabed, the object or the load being coupled to a hoist, such as a hoisting wire in order to enable the object or the load to be lowered to the seabed from a vessel, the apparatus including a body having parts for releasably securing the object or the load to the body and propulsion for moving the body when submerged, whereby the propulsion is positioned offset from the parts for releasably securing the object or the load, in order to be able to induce rotational control on the hoist, when the propulsion is in use.
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FIELD OF THE INVENTION
The present invention relates to closure devices for containers and more particularly to container closure devices for resealing an opened container and even more particularly to such a device for resealing a previously opened carbonated beverage, food, paint or other suitable container.
BACKGROUND OF THE INVENTION
A great deal of effort has been expended to design and produce a satisfactory closure for resealing, for example, partially consumed soft drink and beer containers. Such efforts have resulted in the production of a large number of variations of such devices, but none has reached very large market penetration.
The shortcomings of the prior art devices are numerous and varied. Many such prior art devices are large, i.e. bulky, and unwieldy, i.e. hard to operate, others because of their design cannot be easily cleaned after use, and yet others such as that described in U.S. Pat. No. 3,982,656 require that a portion of the resealing device actually be inserted into the container to obtain satisfactory sealing, a generally unacceptable requirement since it poses the significant risk of contaminating the container contents through the introduction of foreign matter.
Thus, the need for a satisfactory device capable of resealing a previously opened container such as a soft drink can remains, as does the demand for such a product. Additionally, such a device that could be manufactured in varying sizes for purposes of sealing other reusable containers such as paint cans and the like would be similarly useful and desirable.
OBJECT OF THE INVENTION
It is therefore an object of the present invention to provide a container resealing device suitable for use on a variety of reusable containers such as beverage cans that is easy to use, compact and provides for the ability to be cleaned after one or more uses.
SUMMARY OF THE INVENTION
According to the present invention, there is provided a container resealing device comprising a generally semicircular engagement portion joined to but separated from a circular base by a preferably removable spacer to provide a gap capable of engaging the peripheral lip of a container, a vertically movable circular cap including a pliant sealing surface on a first side thereof located between the circular base and the engagement portion and a cam mechanism engaging a second surface of the circular cap so as to permit driving the circular cap against the top of a container with which the gap has been engaged along the peripheral container lip.
According to various preferred embodiments of the present invention, the cam mechanism can incorporate a means for providing a variety of cam settings to adapt to a variety of container configurations, the spacer is a round, axially compressible and expandable spring to permit easy removal thereof for disassembly of the device of the present invention for cleaning and the pliant sealing surface may cover the entire surface of the circular cap or merely comprise a portion thereof adequate to provide a fluid tight seal against a portion of a resealed container.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the container closure device of the present invention engaged with the top of a container in the closed or sealed position.
FIG. 2 is a perspective view of the container closure device of the present invention engaged with the top of a container in the open or unsealed position.
FIG. 3 is partially phantom bottom view of the container closure device of the present invention in the open or unsealed condition.
FIG. 4 is a partially phantom top view of the container closure device of the present invention engaged with a container in the open position.
FIG. 5 is a cross-sectional view of the container closure device of the present invention along the line 5 — 5 of FIG. 4 showing the container closure device of the present invention in the open or unsealed position engaged with the top of a container to be sealed.
FIG. 6 is a cross-sectional view of the container closure device of the present invention along the line 6 — 6 of FIG. 4 .
FIG. 7 is a top plan view of certain of the essential elements of the container closure device of the present invention.
FIG. 8 is a partially phantom view along the line 8 — 8 of FIG. 4 .
FIG. 9 shows the same view as FIG. 5, but with an alternative configuration for the pliant layer.
DETAILED DESCRIPTION
Referring now to FIGS. 1 and 2 that depict container closure 10 of the present invention engaged with the top surface of a container 12 , container closure device 10 comprises an annular base 14 of a size to cover the periphery of the top of container 12 (shown and described in greater detail below), a cam 16 , a cam lever 18 preferably including indicia 20 for indicating whether container closure device 10 is sealed or open, a raised or cam bearing point 22 to provide cam action, a cam shaft 24 extending longitudinally through cam 16 and rotatably engaged with shaft retainers 26 located in opposition atop annular base 14 . It should be noted that the opposing ends 24 ( a ) and 24 ( b ) of shaft 24 as well as mating and opposing shaft engagement apertures 28 a , 28 b and 28 c are preferably of different diameters to permit only a single assembly direction for the purposes described below. Each of shaft retainers 26 preferably includes a plurality of shaft engagement apertures 28 a , 28 b and 28 c of varying depths to permit engagement with container 12 tops having container top ridges of varying heights as described more fully below. Quite clearly, shaft engagement apertures 28 a , 28 b and 28 c of varying depths must be oriented such that opposing ends 24 a and 24 b of cam shaft 24 engage shaft engagement apertures 28 a , 28 b and 28 c of equal depth and diameter to provide smooth and even rotation of cam 16 , as shown in FIGS. 3 and 4. Thus, shaft engagement apertures 28 a , 28 b and 28 c will be aligned in opposing order on opposing sides of annular base 14 as clearly shown in FIGS. 3 and 4. As will be obvious to the skilled artisan, a single shaft engagement apertures 28 of equal height in each of shaft retainers 26 a pair or an even greater number than three of shaft engagement apertures 28 can be used in the successful practice of the present invention. Annular base 14 is preferably comprised of an upper portion 15 and a lower portion 17 that define a gap 19 that serves to retain spacer 36 therebetween. Within gap 19 and forming a portion thereof is a recessed portion 21 . As best shown in FIG. 8, recessed portion 21 is of greater thickness than the combined thickness of annular sealing ring 34 and pressure plate 30 described in detail hereinafter, but of a smaller thickness that the combined thickness of sealing ring 34 , pressure plate 30 and spacer 36 also described in greater detail hereinafter.
As best viewed in FIGS. 5 and 6, container closure device 10 further comprises a pressure plate 30 against which cam 16 , and more specifically raised or bearing point 22 of cam 16 , bears forcing pressure plate 30 downward in the direction of container top ridge 33 about the periphery of container top 32 . This action causes resilient, annular sealing ring 34 to sealingly bear against container top ridge or lip 33 thereby providing a fluid, gas or liquid, proof seal between annular sealing ring 34 and container top ridge 33 which, in the engaged or sealed configuration, is located between annular sealing ring 34 and lower portion 17 of annular base 14 that engages the lower periphery of container top ridge 33 of inserted container 12 .
Clearly, to permit insertion of container 12 into gap 19 , lower portion 17 is semi-circular, i.e. extending only about one half of the periphery of upper portion 15 . More specifically, lower portion 17 is of a size and shape and located so as to provide registration with spacer 36 to permit insertion of container 12 as shown in FIGS. 1, 2 and 5 . It is gap 19 , described in detail below, that serves to capture the peripheral top ridge 33 when container 12 is inserted into container closure 10 of the present invention. Quite obviously, annular base 14 could easily comprise a monolithic member having gap 19 including recess 21 machined, molded or otherwise formed therein rather than being comprised of two distinct parts 15 and 17 . Indeed, elements 15 , 17 and even 26 could be molded into or machined from a single piece of material to form a monolithic structure incorporating all of such elements into a single part.
According to a highly preferred embodiment of the present invention, when upper portion 15 and lower portion 17 are separate parts and must be joined together, they are joined by screws or rivets (not shown) extending therebetween.
While the upper surface of pressure plate 30 is depicted herein as being flat, it will be readily apparent to the skilled artisan that this surface, i.e. that opposite the surface which bears annular sealing ring 34 , could be slightly bowed to reduce the amount of bow that must be included in cam bearing point 22 on cam 16 as shown at 22 a in FIG. 5 .
The presence of spacer 36 is critical to the successful practice of the present invention. Spacer 36 is a generally horseshoe-shaped, radially compressible and expandable, preferably round spring having rounded and extended and rounded ends 40 , best shown in FIGS. 3, 4 and 7 . Ends 40 permit easy insertion of container 12 within spacer 36 thereby positioning container ridge 33 for subsequent engagement in gap 19 by lower portion 17 and sealing by the action of cam 16 depressing pressure plate 30 and in turn engaging resilient surface 34 with container ridge 33 as shown in FIG. 5 . Engagement of lower portion 17 about container 12 as shown in FIG. 5 causes retention of container 12 in container closure device 10 , specifically in gap 19 , while cam 16 is rotated from the open to the closed or sealed position causing sealing and engagement of the various members as just described.
The configuration of spacer 36 as a radially compressible spring also permits its removal from container closure device 10 by slight radial compression thereof for purposes of cleaning after use or use on different product containers. Such cleaning is accomplished by radial compression and removal of spacer 36 thereby allowing pressure plate 30 to drop down into the lower portion of gap 19 , i.e. out of recess 21 from whence it can easily be removed for cleaning.
Referring now to FIG. 8, it will be apparent to those skilled in the art that the thickness of lower portion 23 , i.e. that portion of gap 19 that lies below recess 21 , is somewhat greater than the combined thickness of pressure plate 30 and resilient surface 34 but somewhat smaller than the combined thickness of pressure plate 30 , resilient surface 34 and spacer 36 . Thus when spacer 36 is radially compressed and removed, pressure plate 30 and associated resilient surface 34 can be moved toward lower portion 17 , i.e. dropped into lower portion 23 of gap 19 , and easily removed for cleaning.
While annular sealing ring 34 is depicted in the Figures and described herein as an “annular ring”, it will be readily apparent to the skilled artisan that the “ring” configuration could easily and effectively be replaced by the use of a solid layer or surface of resilient material that covered all or substantially all of the lower surface of pressure plate 30 , so long as adequate contact between container top ridge 33 and the resilient material of “annular ring” 34 is provided to produce the required fluid resistant seal about top ridge 33 . Such an embodiment is depicted in FIG. 9 .
Container closure device 10 may, of course, be manufactured from a wide variety of materials so long as each member is manufactured from a material that provides adequate properties to meet the performance requirements of that particular element. For example, annular base 14 and associated shaft retainers 26 can be fabricated from metal or a suitably stiff polymeric material, although aluminum or steel is specifically preferred depending upon the particular use to which container closure device 10 will be put. Similarly, while cam 16 and all of its various elements, shaft 24 , etc. can be fabricated from a variety of polymeric and metallic materials, it is preferred that they be fabricated from aluminum or steel for durability.
Spacer 36 is preferably fabricated from spring steel, although, again, a suitable polymeric material that provides the required radial expandability and compressibility could be substituted therefor.
In use, container closure device 10 is utilized by sliding ridge 33 of a container 12 into gap 19 while cam 16 is in the open position and then once ridge 33 is properly engaged within gap 19 and with spacer 36 , as described hereinabove, rotating lever 18 to the sealed position, rotation through about 180°, causing cam bearing point 22 to bear on the top surface of pressure plate 30 thereby forcing pressure plate 30 downward and resulting in resilient annular ring 34 tightly engaging ridge 33 thereby sealing the container.
While container closure 10 has been described herein largely in connection with soft drink, beer or other similar containers, it should be noted, that container closure device 10 is similarly useful, in an appropriate size, for use on, for example, paint containers, food containers and other similar containers that need to be tightly sealed against the infiltration or exfiltration of a fluid such as a gas or liquid for extended periods of time.
While cam 16 and its associated bearing point(s) 22 , ( 22 a ) and cam lever 18 can be oriented to permit sealing of container closure device 10 in either direction of movement of cam lever 18 , it is specifically preferred that these various members be oriented such that movement of cam lever 18 from the “open” to the “sealed” condition be such that such movement tends to push container closure device 10 toward tighter engagement with container 12 as shown in the various Figures attached hereto.
As described herein, container closure device 10 has been described as being circular or round. It will be obvious to the skilled artisan that the principles and designs described herein could be easily transferred to a container closure device useful for sealing square, rectangular, oval or other shaped containers having an appropriate top ridge with which engagement of a resilient sealing surface can be achieved. The fabrication of such a closure device would involve largely the alteration of the shape of the various members to obtain such a device.
As the invention has been described, it will be apparent to those skilled in the art that the same may be varied in many ways without departing from the spirit and scope of the invention. Any and all such modifications are intended to be included within the scope of the appended claims.
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A container closure device comprising an engagement portion joined to but separated from a base to define a gap capable of engaging the peripheral lip or top ridge of a container and including a radially compressible spacer in the gap, a vertically movable cap or plate including a pliant sealing surface on a first side thereof located between the base and the engagement portion and a cam mechanism engaging a second surface of the cap so as to permit driving the cap and its associated pliant sealing surface against the top ridge of the container with which the gap has been engaged.
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BACKGROUND OF THE INVENTION
The present invention relates in general to headed cotter pins or like mechanical fastening devices and has specific reference to a headed cotter pin provided with safety means for retaining the pin on shafts, spindles, gudgeon pins, studs or anchoring bolts through which the pin is inserted.
THE PRIOR ART
As a rule, cotter pins of this type are provided with a flexible spring-like ring or clip pivoted in a pair of off-set holes provided laterally in the pin head, whereby the ring is urged by its inherent resiliency in its holding position.
However, cotter pins of this general type are scarcely reliable. In fact, the ring flexibility decreases after a relatively short time and thus the ring tends to open, inasmuch as the pins to be controlled or fastened thereby are generally exposed to jarring and/or shocks. Moreover, when the ring is open, the pin escapes and the parts previously coupled thereby are thus released and exposed to serious damages.
Various means have already been proposed for avoiding these inconveniences, for example by varying the angle formed between the axes of the off-set holes in the pin head, and also by varying the shape and quality of the spring-forming flexible ring. Another proposition consisted in forming either rounded bosses on the pin head for cooperating with the ring, or a notch at the base of the pin body engaged by the clip. However, none of these solutions proved to be really satisfactory in actual practice, for the ring ends still tend to divaricate completely as a consequence of wear and tear, or of relatively fierce shocks as currently observed in the operation for example, of farming machines.
SUMMARY OF THE INVENTION
It is the primary object of the present invention to solve the problems still set by cotter pins according to the present state of the art by providing an improved safety cotter pin capable, through its various forms of embodiment, of very efficiently retaining the ring in its closed position.
The safety cotter pin according to the present invention comprises a pin, a head formed integrally with one end of the pin, and a substantially annular device or open loop having its pivot-forming ends fulcrumed to said head, on either side thereof, on substantially parallel spaced transverse axes, this annular device being adapted to surround the part through which the pin is inserted, in order to prevent any undesired removal of the pin, retaining means also being provided for preventing the annular device from being released or from departing from the closed position in which it locks the cotter pin against any undesired removal or release.
According to the present invention, said retaining means comprises a stop element mounted on the pin head and adapted to cooperate with at least one of the end portions of the annular device in order to limit the permissible movement of this device in the direction away from said closed position.
In a first and preferred form of embodiment said stop element may consist of a transverse stud mounted on said head and capable of limiting the angular movement of said annular device.
In a modified version of this first and preferred form of embodiment, in which the ends of the annular device or open loop are pivoted to said head about two off-set transverse axes, said transverse stud may advantageously consist of one of the pivot-forming end portions of the annular device, which extends through said head and projects beyond the opposite pivot-forming end portion of the annular device.
In this modified version, said retaining means may also comprise a wedge member movable along said stud-forming end of the annular device so that said wedge member can be either disposed between said stud-forming end and said other, pivot-forming end portion of the annular device, or removed therefrom.
In a further modified version the ends of the annular device are also pivoted to said pin head about off-set transverse axes, and said transverse stud extends completely through said head and has formed at one end a shoulder-like stop collar adapted to bear against said head and a cavity adapted to receive one of the pivot-forming ends of said annular device, the other end of said stud projecting in front of the end portion of the annular device which is adjacent said other pivot-forming end thereof in order to constitute said stop element.
In this last-mentioned modified version said other end of the stud may advantageously be bevelled so that the stud itself acts as a bolt engageable by the end portion of the annular device which is adjacent to the other pivot-forming end thereof.
In this modified version, said other end of the stud may, in a different form of embodiment, comprise a notch opposite a solid portion thereof, said stud comprising means permitting rotation of same so that either said notch or said stop-forming solid portion can be brought in front of the said end portion of said annular device.
In this other modified version translation means may, in a different form of embodiment, be provided for moving said stud across and inside said head between a forward position in which said other end of said stud constitutes said stop, and a retracted position in which said other end of said stud is free and the annular device is released.
In a particularly advantageous form of embodiment, said stud collar and said head may comprise registering inclined faces, and said stud may comprise means for rotating same, whereby the rotation of said stud will allow the transverse movement of said stud by causing said inclined faces to slip on each other from said forward position and said retracted position. Moreover, said inclined faces may be shaped to hold said stud in its forward or retracted position even when the annular device is caused to pivot.
In a third modified version of said form of embodiment of the safety cotter pin of this invention, said transverse stud may extend through said head and be provided with at least one notch and one stop-forming solid portion, and this stud may be movable so that either its solid portion or its notch can be brought in front of the end portion of the annular device adjacent one of the pivot-forming ends thereof.
In this third form of embodiment, said notch and said solid portion may follow each other in a transverse direction, and means may be provided for causing the transverse translation of said stud.
In a modified version of this third form of embodiment, said notch and said solid portion may oppose each other and means may be provided in this case for pivoting said stud.
In a fourth modified version of this form of embodiment, said transverse stud may be secured to the pin head so as to project laterally in front of at least the end portion of the annular device adjacent one of its pivot-forming ends, a wedge member being movable along said stud so as to lie between said stud and the end portion of the annular device and be removable therefrom.
In these last two modified versions said stud may advantageously extend in front of the annular device. However, if this device comprises at least one extension laterally of said head beyond one of its pivot-forming ends, the transverse stud may extend across the head at the rear of said extension.
In a fifth modified version of said form of embodiment, said transverse stud may be rigid with at least one link pivoted to said head and adapted to pivot so as to cause said stud to lie in front of the end portion of the annular device when the latter is in its closed position.
In a second preferred form of embodiment of the safety cotter pin according to the present invention, wherein the pin body has a substantially axial notch formed therein, into which the annular device can be inserted, it is contemplated that at least one of the pivot forming ends of the annular device be fulcrumed in a lateral elongated recess formed in said head and that said stop-forming element consists of a stud or needle which, in its forward position, penetrates into said recess and constitutes a stop member with respect to said pivot forming end of the annular device in said recess so as to retain said annular device in said axial notch.
In a third preferred form of embodiment of the safety headed cotter pin according to the instant invention said stop forming element may consist of at least one lateral boss formed on said head and provided with a transverse face engaged by the end portion of said annular device which is adjacent one of said pivot-forming ends when the annular device is in its closed position, said boss being shaped to permit the pivotal movement of said annular device to its closed position.
In a fourth preferred form of embodiment of the safety headed cotter pin according to this invention, said stop forming element may consist of a ring rigid with the annular device so as to form therewith a flexible V-shaped spring, said ring bearing against a stop formed on and in front of said head when said spring is V-shaped, in order to keep said annular device in said closed position.
In a modified version of this specific form of embodiment, the annular device and said ring may constitute a single and same member.
The various forms of embodiment of the improved safety headed cotter pin with annular retaining member and their modified versions according to the present invention will now be described more in detail, by way of illustration, not of limitation, with reference to the accompanying drawings.
THE DRAWINGS
FIGS. 1 to 3 illustrate different versions of a first form of embodiment;
FIGS. 4 to 8 illustrate different versions of a second form of embodiment;
FIGS. 9 to 18 illustrate different versions of a third form of embodiment;
FIGS. 19 and 20 illustrate two versions of a fourth form of embodiment;
FIGS. 21 and 22 illustrate a fifth form of embodiment, and
FIGS. 23 to 25 illustrate modified versions of a sixth form of embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
As illustrated in FIGS. 1 and 2 of the drawings, a safety headed cotter pin according to the present invention comprises essentially a head 2, a pin or body 3 formed integrally with said head 2 and a substantially annular device 4 constituting a kind of open loop of which the two ends 5 and 6 are engaged in holes 7 and 8, respectively, formed in the head 2 so as to constitute means for pivoting the annular device 4 about substantially parallel axes; the pin illustrated in FIGS. 1 and 2 is designated in general by the reference numeral 1. In this example the body 3 extends through a substantially diametral hole B formed in a shaft A, the ring 4 being adapted on the one hand to surround said shaft A by bearing on the spindle 3 so as to prevent the removal of the pin 1, and on the other hand to be moved away from this position for releasing the pin when required.
In the example illustrated in FIGS. 1 and 2, the pivot-forming end 5 of ring 4 extends completely through the head 2 and projects therefrom as shown at 9; it being somewhat spaced laterally from and parallel to the adjacent end portion 6 of ring 4 to constitute a stud 9. With this arrangement, the ring can move angularly through an angle of about 15° to 30° between the body 3 and the stop forming stud 9. Since this ring 4 is flexible, it constantly tends to move away from stud 9 and to bear against the body 3. When pulled to a position in which it abuts the stud 9, this ring will not interfere with its mounting on shaft A or with its removal therefrom, for its permissible angular movement is sufficient for clearing the shaft end.
In the modified structure illustrated in FIG. 3, an annular, flanged and cup-shaped wedge member 16 is mounted on the stud 9 and urged towards the head 2 by a spring 16a bearing with one end against said wedge member 16 and with the opposite end against a washer 16b retained by the outer mushroom-shaped end of stud 9. If desired, this wedge member may be disposed between the end portion 4a of ring 4 and the stud 9 so as to lock said ring 4 in bearing engagement with the pin body 3, but it can be removed by moving the member 16 against the force of spring 16a to open the ring 4 as already explained hereinabove with reference to the first form of embodiment shown in FIGS. 1 and 2.
In the following forms of embodiment the stop-forming stud is not an integral portion of ring 4 but formed independently thereof.
In the example shown in FIG. 4, the transverse stud 109 extends through the head 102 of pin 101 and has at one end a stop collar constituting a shoulder 112 held against the head 102 by the flexibility of ring 104 and also by a recess 113 receiving the pivot-forming end 105 of ring 104, the opposite pivot-forming end being fulcrumed to head 102. The other end 109a of stud 109 is bevelled and projects just beyond the end portion 104a of ring 104 which is adjacent its other pivot-forming end 105. Since the ring 104 is flexible and the end 109a of stud 109 is bevelled, this stud 109 acts as a lock bolt to keep the ring 104 in its closed position in which it bears against the pin body 103 while permitting the complete opening thereof under a considerable effort. In a modified version, it would be possible to form male screw-threads on stud 109, to tap the head 102 and provide a hexagonal collar 112, thus permitting a transverse translation of stud 109 for removing the end 109a from the end face 104a.
As in the example illustrated in FIG. 4, the safety cotter pin shown in FIGS. 5 and 6 comprises a transverse stud 209 extending through the head 202 and having a stop collar 212 bearing against said head 202 and a recess 213 receiving the pivot-forming end 205 of ring 204, the other pivot-forming end 206 of this ring being pivoted directly to the head 202.
In this example, the other end 209a of stud 209 comprises an outer solid portion 214a and a notch or recess 214, both registering with the end portion 204a adjacent the pivot-forming end 206 of ring 204. The end 209a of stud 209 comprises a diametral slot 217 engageable by a screwdriver for rotating this stud 209 so that it can present, in alignment with the end portion 204a of ring 204 adjacent its pivot-forming end 206, either the solid portion 214a (which in this case acts as a stop member keeping the ring 204 in its closed position), or the notch 214 permitting an angular excursion of ring 204 through an angle of 15 to 30 degrees, for inserting or removing the stud 201 as in the example illustrated in FIGS. 1 and 2.
It will be seen that the screwdriver slot 217 could be replaced by any other known means permitting the rotation of stud 209, such as a lever or, on this stud 209, polygonal internal or external faces adapted to be engaged by a spanner or the like.
In the example illustrated in FIGS. 7 and 8, the safety cotter pin 301 also comprises a stud 309 extending through the head 302 and has at one end a shoulder-forming stop collar 312 and a recess 313 receiving the pivot-forming end 305 of ring 304 of which the opposite end 306 is pivoted to the head 302 at an off-set position.
In this example, the head 302 of cotter pin 301 and the shoulder 312 of stud 309 are provided with registering flat faces 302a and 312a, respectively, inclined in relation to the axis of stud 309, so that when the stud 309 is rotated the inclined flat faces 302a and 312a of head 302 and the shoulder 312, in conjunction with the flexibility of ring 304, cause the stud 309 to move transversely from a forward position to a retracted position, the ring constantly urging the stud to its forward position.
In this forward position the faces 302a and 312a engage each other and the other end 309a of stud 309 projects beyond the end portion 304a of ring 304 which is adjacent its pivot-forming end 306, so as to constitute a stop means for the ring 304 when the latter is folded to its closed position in engagement with the pin body 303, this position of stud 301 being visible in FIG. 8.
In the retracted position, said inclined faces 302a and 312a of head 302 and shoulder 312 form a V, and the end 309a of stud 309 is recessed within the head 302 so that ring 304 is released; thus, this ring 304 can be moved from its closed position to its fully open position, and vice versa. This position of stud 309 is visible in FIG. 7 showing that the ring 304 can move past the end 309a of stud 309 without interfering therewith.
To keep the stud 309a in its retracted position, there is provided, in the projecting portion of head 302, a flat face 302b inclined in the opposite direction with respect to the face 302a engaged by face 312a of shoulder 312 when the stud 309 is retracted, so that the ring 304 can be actuated without pivoting the stud 309.
In the example illustrated, to pivot the stud 309 the shoulder 312 consists of a nut. However, a different arrangement, comprising, for example, a screwdriver slot, may be contemplated if desired.
In the modified version of the form of embodiment illustrated in FIGS. 7 and 8, the inclined surfaces 302a, 302b and 312a may be curved instead of flat.
In the example shown in FIG. 9, the ring 404 is pivoted symmetrically on either side of head 402 of cotter pin 401 by engaging a through hole 408 and a transverse pin 409 extends completely through the head 402 and can project in front of the arms 404a and 404b of ring 404 which are adjacent the ring ends constituting said pivot means 405 and 406. The stud 409 has an annular groove or notch 414 formed therein between two solid portions 414a and 414b, with portion 414a lying within the head 402 and having a length corresponding substantially to the head width. The stud 409 can be moved transversely from a first position, in which the end portion 404a of ring 404 is free and the groove 414 registers with the end portion 404b of ring 404, and a second position in which the solid portions 414a and 414b of stud 409 register respectively with the end portions 404a and 404b of ring 404. In said first position, the ring 404 can be moved through an angle of about 15 to 30 degrees, the arm 404b penetrating into the notch 414, whereas in the second position ring 404 is locked and engaged against the spindle 403.
In the example shown in FIG. 9, the solid portion 414a of stud 409 is plain whereby the transverse movement of this stud is a simple sliding movement.
On the other hand, in the example illustrated in FIG. 10 the general structure of pin 501 is substantially similar to that of pin 401 of FIG. 9, and the portion 514a of stud 514 is provided with screw threads engageable in a corresponding tapped hole of head 502, one end of stud 514 being provided with a screwdriver slot 517 so that the stud 514 can be moved transversely from said first position to said second position, or vice versa, by screwing the stud in or out.
In contrast to the cotter pins 401 and 501 shown in FIGS. 9 and 10, respectively, the head 602 of cotter pin 601 illustrated in FIG. 11 receives therethrough a transverse stud 609 provided, on either side of this head, symmetrically and in front of the end portions 604a and 604b of ring 604, with a stop-forming solid portion 614a opposite a recess or notch 614. The ring can be rotated to present in front of said end portions 604a and 604b, either the stop-forming solid portion, keeping the ring 604 in bearing engagement with the pin body 603, or the notches 614 permitting pivoting of said ring 604 through an angle of about 15 to 30 degrees, the end portions 604a and 604b of ring 604 penetrating into said notches 614. To pivot the stud 609, it is also possible to contemplate at one of its ends either a screwdriver slot or a polygonal head engageable by a suitable spanner.
FIG. 12 illustrates a cotter pin 701 adapted to be utilized like the cotter pin 601 illustrated in FIG. 11. However, in this case the stud 709 is hollow and the notches 714 are bounded by solid portions 714a constituting transverse end lugs.
FIGS. 13, 14 and 15 illustrate modified forms of embodiment of studs 609 and 709, suitable for use in cotter pins 601 and 701 shown in FIGS. 11 and 12.
In FIG. 13 it will be seen that a tubular stud 809 has two notches 814 formed therein and an outwardly bent lug 819 adapted to limit the rotation of stud 809.
As clearly shown in FIG. 14, the tubular, polygonal-sectioned stud 909 is adapted to be engaged by a suitable spanner, and comprises at one end a notch 914 bounded by a transverse end lug 915 and at its opposite end an out-turned lug 912 constituting a convenient shoulder adapted to abut the cotter pin head (not shown).
Finally, FIG. 15 illustrates a tubular stud 1009 having a flat outer face 1018 adapted to bear against the ring 1004 for locking the stud 1009 against rotation.
The cotter pin 2001 shown in FIG. 16 constitutes a modified form of embodiment of the cotter pins illustrated in FIGS. 9 to 15 of the drawings. Its stop-forming transverse stud 2009 is disposed behind an extension 2004a of ring 2004 beyond the pivot-forming axis 2005 thereof, said stud 2009 having if desired, the structure of any one of the studs illustrated in FIGS. 9 to 15.
In the exemplary form of embodiment shown in FIG. 17, the stud 3009, instead of passing through the head 3002 of cotter pin 3001, extends in front of this head and is carried by a pair of lateral links 3021 pivoted to said head 3002 by means of a transverse pin 3020 so that the stud 3009 can be placed in front of ring 3004 and kept in its closed position in which it engages the pin body 3003, or above the head 3002 to permit the opening of said ring. Moreover, a return spring 3021a is associated with the links 3021 for urging same in the direction to hold the ring 3004.
In contrast with the examples illustrated in FIGS. 4 to 17 of the drawings, FIG. 18 shows a cotter pin 4001 corresponding to the pin illustrated in FIG. 3. In fact, the head 4002 of this cotter pin is provided with a transverse stud 4009 secured to this head and extending in front of the end portion 4004a of ring 4004 so as to be somewhat spaced therefrom to limit the permissible opening of ring 4004 to an angle of about 15° to 30°. The stud 4009 is screw-threaded and carries a wedge member 4016 adapted to be screwed in or out along said stud 4009 and disposed inside or outside of the gap left between the end portion 4004a of ring 4004 and the stud 4009, for locking the ring 4004 in relation to the cotter pin body 4003.
In the examples illustrated in FIGS. 19 and 20, the cotter pin 5001 has a different structure. In fact, the outer end of its body 5003 has an axial notch 5026 formed therein for engagement by the ring 5004. The pivot-forming ends of ring 5004 are engaged in elongated lateral recesses 5027 so that the corresponding ring 5004 can move axially in said recesses 5027 and thus clear the end of the cotter pin body 5003 before eventually engaging the relevant end notch 5026. To keep the ring 5004 in this position there is provided, in the example illustrated in FIG. 19, a stud consisting of a set screw 5029, or alternatively, in the example illustrated in FIG. 20, a spring-loaded bolt 5009, said set screw 5029 and bolt 5009 being adapted to penetrate into the elongated recess 5027 and thus act as a stop means to the pivot-forming ends of ring 5004.
In the example illustrated in FIGS. 21 and 22, the cotter pin 6001 is free of any stud means but its head 6002 comprises an integral lateral boss 6030 having a continuous side face 6031 and a transverse face 6032 engageable by the end portion 6004a of ring 6004 adjacent its pivot-forming end 6005 when the ring 6004, in its closed position, engages the cotter pin body 6003 and is thus prevented from opening undesiredly. Since the boss 6030 of head 6002 of this cotter pin has a continuous side face 6031, the ring 6004 can pivot freely to its closed position in which its portion denoted 6004a extends behind said transverse face 6032. On the other hand, to open the ring 6004 it will be necessary to cause the end portion 6004a of ring 6004 to rise along the lateral face 6031 of boss 6030. In a modified version, the face 6032 of boss 6002 may be so inclined that the ring portion 6004a will tend to move away from the edge of boss 6030. In another modified version, this face 6032 could also be somewhat spaced from the end portion 6004a when the ring 6004 bears against the cotter pin body 6003.
In the example illustrated in FIGS. 23 and 24, the cotter pin 7001 is free of any stud as in the last-described forms of embodiment but comprises, as a means for stopping the ring 7004, a second ring 7024 connected to ring 7004 via a spring-like element 7025 so that the two rings 7024 and 7004 form together, a deformable V-shaped assembly. The head 7002 of cotter pin 7003 illustrated in FIGS. 23 and 24 comprises an extension 7026 adapted to receive the upper end of ring 7024 when its companion ring 7004 is moved against the cotter pin body 7003, as shown in FIG. 23. When both rings 7024 and 7004 are moved toward each other against the resilient force of spring 7025, ring 7024 is released from said extension 7026, and ring 7004 can thus move away from the cotter pin body 7003 by pivoting through an angle of about 15 to 30 degrees, as in the example shown notably in FIGS. 1 and 2, to permit the insertion or the removal of the cotter pin 7003.
FIG. 25 shows a modified form of embodiment of the structure illustrated in FIGS. 23 and 24, wherein the rings 7004 and 7024 form together a one-piece member obtained by coiling directly two turns of a wire, the two rings forming a V-shaped structure.
Of course, the present invention should not be construed as being strictly limited by the specific forms of embodiment described and illustrated herein, since many other modifications and changes may be brought thereto without departing from the basic principles of the invention, as set forth in the following claims.
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This safety headed cotter pin having an annular holding device comprises a substantially cylindrical body, a head formed integrally with this body, an annular device adapted to prevent any undesired removal of the cotter pin and retaining means comprising a stop-forming element rigid with the head and adapted to cooperate with at least one of the end portions of the annular device in order to limit the permissible movement of this device in the direction away from its closed position, this cotter pin being intended notably for use in various farming vehicles and machines, for example for keeping mechanical component elements on parts such as shafts and the like.
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BACKGROUND OF THE INVENTION
The present invention relates generally to the boring of horizontal holes and, more particularly, to the guiding of a horizontal boring tool. Still more particularly, the present invention relates to the control of the guidance of such a tool, especially using a magnetic sensing system for sensing tool location and attitude.
The present invention has particular application in the installation of conduits and pipes by various utilities, such as gas, telephone and electric utilities. Such utilities are often faced with the need to install or replace such conduits or pipes under driveways, roads, streets, ditches and/or other structures. To avoid unnecessary excavation and repair of structures, the utilities use horizontal boring tools to form the bore holes in which to install the conduits or pipes. Such tools have been unsatisfactory to the extent that their traverse has not been accurate or controllable. All too frequently other underground utilities have been pierced or the objective target has been missed by a substantial margin. It has also been difficult to steer around obstacles and get back on course.
The directional drilling of holes has probably reached its greatest sophistication in the oil fields. Typical well surveying equipment utilizes magnetometers, inclinometers and inertial guidance systems which are complex and expensive. The wells drilled are substantially vertical. In respect to utilities, Bell Telephone Laboratories Incorporated has designed a system for boring horizontal holes wherein the direction of drilling is controlled by deploying a three wire antenna system on the surface of the earth and detecting the position and attitude of the drilling tool in respect thereto by pickup coils on the tool. The signals detected are then used to develop control signals for controlling the steering of the tool. See, for example, MacPherson U.S. Pat. No. 3,656,161. Such control systems have been relatively expensive, and it is not always easy or convenient to deploy the antenna, for example, over a busy highway.
Steering control is also known in controlling vehicles, aircraft and missiles. In one form of control, a radio beacon is used for guidance, the aircraft simply following a beacon to a runway.
SUMMARY OF THE INVENTION
The present invention may be used with various boring tools. The preferred embodiment was designed for a piercing tool advanced by percussion and steered by active and passive vanes. In accordance with the invention, a coil is disposed on the tool and energized at relatively low frequency to provide a varying magnetic field extending axially from the tool and providing lines of magnetic flux substantially symmetrically disposed about the tool axis. First and second pickup coils are disposed at a distance from the tool. These coils have respective axes at a substantial angle with respect to each other and are mounted to sense the changing flux linked thereby and produce respective first and second electrical signals. The coil arrangement provides respective null signals when the respective axes of the pickup coils lie substantially perpendicular to the tool axis and the coils are balanced about the tool axis. The signals therefore indicate the attitude of the tool relative to the coils. A third pickup coil may be used to sense the range of the tool when the third coil has an axis extending generally toward the tool, with its output used to normalize the detection signals. The axes of the three coils are preferably at angles of 90° from each other.
The signals from the respective pickup coils may be used to determine the attitude of the tool relative to the pickup coils, and the information used to control the steering mechanism of the tool. This may be done automatically. Because this is a null-based system, the control signal may simply operate the steering mechanism to turn the tool to reduce the deviation from null. This causes the system to be a homing device, like a beacon, and directs the tool along a path to the coils. On the other hand, it may be desirable to deviate from a straight path, as to miss obstacles. The system may then direct the tool out of the path, around an obstacle, and back on course.
Thus, an important aspect of the present invention is to provide a null detection system to determine the attitude of a horizontal boring tool relative to detection coils and for controlling the steering of the tool. Another aspect is to provide a control system for such a tool wherein the tool may be steered to home in on the detection coils. Other aspects, objects and the advantages of the present invention will become apparent from the following detailed description, particularly when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a vertical sectional view, partly diagrammatic and partly in perspective, of a horizontal boring operation, showing a horizontal boring tool controlled by a control system according to the present invention;
FIG. 2 is a diagrammatic illustration of the sensing system of the control system of the present invention;
FIGS. 3A, 3B, 3C and 3D are diagrammatic illustrations of relationships of one sensing coil and the magnetic flux generated by the flux generator of the sensing system shown in FIG. 2; and
FIG. 4 is a diagrammatic illustration of the electrical circuitry of the sensing system shown in FIG. 2.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
In FIG. 1 is illustrated a horizontal boring operation in which a borehole 10 is being bored through the earth 12 under a roadway 14 by a horizontal boring tool 16. The particular tool illustrated and for which the preferred embodiment of the present invention was specifically designed is a pneumatic percussion tool, operated like a jackhammer by a motive mechanism 17 using compressed air supplied by a compressor 18 by way of an air tank 19 over a supply hose 20. The tool 16 is elongated and has a tool axis 22 extending in the direction of its length. The lead end of the tool 16 has a piercing point (or edge) 24 eccentric of the axis 22. The operation of the percussion tool drives the point 24 through the earth, advancing the tool forward, but slightly off axis.
The tool 16 includes a plurality of steering vanes 26 which may be actuated by pneumatic or hydraulic control energy provided over pneumatic or hydraulic control lines 28 from a controller 30 to control the direction and rate of rotation of the tool 16 about its axis. Control signals may also control the operation of the motive mechanism 17. The controller 30 is supplied with air from the compressor 18 over a hose 32. The steering vanes 26 may be turned to cause the tool to rotate at a relatively constant rate. The tool then spirals a bit but advances in a substantially straight line in the direction of the axis 22 because the piercing point 24 circles the axis and causes the tool to deviate the same amount in each direction, averaging zero. If the vanes 26 are returned to directions parallel to the axis 22, the rotation may be stopped with the tool in a desired position, from which it advances asymmetrically in a desired direction. As will be described below, the present invention permits an operator to identify the rotational orientation of the tool 16 about its axis 22 and, hence, to direct the advance of the tool.
The objective is to bore a hole 10 relatively horizontally between an input pit 34 and a target pit 36 beneath such obstacles as the roadway 14. The hole 10 must avoid piercing other utility lines 38 or sewers 40 or other buried obstacles. These may be identified and located from historical surveyor's drawings or may be located by some other means as by a metal detector or other proximity device 42. Armed with this information, an operator may start the tool off easily enough from the input pit 36 in a direction that avoids nearby obstacles and may plot a course that would miss all more distant obstacles. The difficulty is in assuring that the tool follows the plotted course. That is the function of the present invention.
The present invention is directed to a control system for sensing the attitude of the tool 16 and for controlling the steering vanes 26 to direct the tool along the plotted course. The control system includes an electromagnetic source 44 affixed to the tool 16 for generating appropriate alternating magnetic flux, a sensing assembly 46 disposed in one of the pits 34, 36, preferably the target pit 36, and circuitry in the controller 30 which is powered from a motor-generator set 48.
Reference may be made to FIG. 2 for an understanding of the preferred arrangement of the electromagnetic source 44 and the sensing assembly 46. The electromagnetic source 44 comprises an axial coil 50 and a transverse coil 51 rigidly mounted on the tool 16. The coils 50 and 51 are alternatively energized from the motor-generator power source 48 through a controlled power supply section 52 of the controller 30 over lines 53. The power source 48 operates at a relatively low frequency, for example, 20 Hz. The axial coil 50 generates an axial alternating magnetic field which produces lines of magnetic flux generally symmetrically about the axis 22 of the tool 16, as illustrated in FIG. 3. The tool 16 itself is constructed in such manner as to be compatible with the generation of such magnetic field and, indeed, to shape it appropriately. The transverse coil 51 generates a transaxial alternating magnetic field substantially orthogonal to the axis 22 in fixed relation to the direction of deviation of the point 24 from the axis 22 and, hence, indicative of the direction thereof.
The sensing assembly 46 is formed of three orthogonal pickup coils 54, 56 and 58, as shown in FIGS. 2 and 4, which may be called the X, Y and Z coils, respectively. These pickup coils are axially sensitive and can be of the box or solenoidal forms shown in FIGS. 2 and 4. The center of the coils may be taken as the origin of a three-dimensional coordinate system of coordinates x, y, z, where x is the general direction of the borehole, y is vertical and z is horizontal. The coils 54, 56 and 58 have respective axes extending from the origin of the coordinate system in the respective x, y and z directions.
In FIGS. 3A, 3B, 3C and 3D are illustrated four possible unique relationships of a sensing coil, the Y coil 56 as an example, to the lines of flux 60 of the axial magnetic field generated by the axial coil 50 in the tool 16. In FIG. 3A is shown the relationship when the X axis and the tool axis 22 lie in the same plane with the Y axis of the coil 56 normal to that plane. That is the relationship when the tool 16 lies on the plane XZ (the plane perpendicular to the Y axis at the X axis) with the axis 22 of the tool in that plane. In FIG. 3B is shown the relationship when the tool 16 lies in the plane XZ with the tool axis 22 not in that plane. That is the relationship when the tool 16 is tilted up or down (up, clockwise, in the example illustrated). In FIG. 3C is shown the relationship when the tool 16 is displaced up or down from the plane XZ (up, in the example illustrated) with the tool axis 22 parallel to the plane XZ. Other relationships involve combinations of the relationships shown in FIGS. 3B and 3C; that is, where the tool 16 lies off the XZ plane and has a component of motion transversely thereof. Shown in FIG. 3D is the relationship where the combination of displacement (FIG. 3C) and tilting (FIG. 3B) places the coil axis Y normal to the lines of flux 60 at the coil. The lines of flux shown in FIGS. 3A, 3B, 3C and 3D are for conditions when the tool axis 22 lines lies in the XY plane (containing the X and Y axes), but the principle is the same when the tool lies out of such plane. The lines of flux linking the Y coil 56 would be different, and the relative signals would be somewhat different. There would, however, still be positions of null similar to those illustrated by FIGS. 3A and 3D.
As can be seen by inspection and from the principle of symmetry, the pickup coil 56 will generate no signal under the condition shown in FIG. 3A because no flux links the coil. On the other hand, under the conditions of FIGS. 3B and 3C, signals will be generated, of phase dependent upon which direction the magnetic field is tilted or displaced from the condition shown in FIG. 3A. Further, under the condition shown in FIG. 3D, the effect of displacement in one direction is exactly offset by tilting so as to generate no signal. As may also be seen from FIG. 3D, if the tool 16 is off course (off the XZ plane) but the relationship shown in FIG. 3D is maintained, the tool will move toward the sensing assembly 46 keeping the sensing assembly on a given line of flux 60. That is, the tool 16 will home in on the sensing assembly 46 and get back on course in respect to vertical deviation. Similar relationships exist in respect to the Z coil 58 and horizontal deviation. The outputs of the pickup coils 56, 58 are applied through a signal conditioner 62 to a display 64 in the controller 30.
The relationships shown in FIG. 3 can also be analyzed geometrically as shown in FIG. 3, where A is the angle between the tool axis 22 and a line 65 connecting the center of the tool with the center of the pickup coil 56, and B is the angle between the line 65 and the reference axis X, perpendicular to the axis Y of the sensing coil 56.
The well known equation for radial flux density B R and angular flux density B A are:
B.sub.R =2 K.sub.1 cos A (1)
B.sub.A =K.sub.1 sin A (2)
where K 1 is a constant proportional to the ampere-turns for the axial coil 50 and inversely proportional to the cube of the distance between the tool 16 and the sensing coil 56. The signal V thereupon developed in the pickup coil 56 is proportional to the sum of flux components parallel to the coil axis Y. That is,
V=K.sub.2 (B.sub.R sin B+B.sub.A cos B) (3)
where K 2 is a calibration factor between the developed pickup voltage and time-rate-of-change of the magnetic field. From the combination of Equations (1), (2) and (3):
V=K.sub.3 (2 cos A sin B+sin A cos B) (4)
when K 3 =K 1 K 2 . As is evident from FIG. 3D, when the flux at the coil 56 is normal to its axis Y, the two components balance, i.e., B R sin B=-B A cos B, making V=O.
The circuitry for operating the present invention is shown in greater detail in FIG. 4 in block diagram form. As there shown, the output of the pickup coil 56 is amplified by an amplifier 66 and applied to a synchronous detector 68 to which the output of a regulated power supply 70 is also applied. The regulated power supply 70 is driven by the same controlled power supply 52 that drives the coils 50, 51 and produces an a.c. voltage of constant amplitude in fixed phase relationship to the voltage applied to the axial coil 50. In the simplified diagram of FIG. 4, the power supply 52 may be considered as part of the motor-generator 48, although in fact it is preferably located in the controller 30, as stated above. The synchronous detector 68 therefore produces a d.c. output of magnitude proportional to the output of the Y coil 56 and of polarity indicative of phase relative to that of the power supply 70. An amplifier 72 and a synchronous detector 74 produce a similar d.c. output corresponding to the output of the Z coil 58. The outputs of the respective synchronous detectors 68 and 74 are applied to the display 64 which displays in y, z coordinates the combination of the two signals. This indicates the direction or attitude the tool is off course, permitting the operator to provide control signals over the control lines 28 to return the tool to its proper course or to modify the course to avoid obstacles, as the case may be.
The extent to which the tool is off a course leading to the target is indicated by the magnitude of the signals produced in the coils 56 and 58. However, the magnitude of the respective signals is also affected by the range of the tool. That is, the farther away the tool, the lesser the flux density and, hence, the lesser the signals generated in the respective pickup coils 56 and 58 for a given deviation. It is the function of the X coil 54 to remove this variable. The X coil is sensitive to axial flux density substantially exclusively. The y and z directed flux components have negligible effect on its output where the tool 16 lies within a few degrees of the x direction; e.g., 3°. The signal from the pickup coil 54 is amplified by an amplifier 76 and detected by a synchronous detector 78 to provide a d.c. output proportional to the flux density strength at the X coil 54. This signal is applied to a control circuit 80 which provides a field current control for the power supply 52. This provides feedback to change the power applied to the axial coil 50 in such direction as to maintain constant the output of the X coil 54. This makes the flux density at the sensing assembly 46 relatively constant, thus normalizing the outputs of the Y and Z coils 56, 58 and making their outputs relatively independent of range. However, if wide deviations from direct paths between the launch and exit points are expected, the total magnitude of the magnetic flux density should be used for this normalizing function. This magnitude may be developed by appropriately combining the outputs from the three pickup coils.
It is one thing to know where the tool is and its attitude. It is another to return it to its course. That is the function of the transverse coil 51. The power from the power supply 52 is applied to the tool 16 through a switch 82. With the switch 82 in position 1, the axial coil 50 is energized, providing the mode of operation explained above. With the switch 82 in position 2, the transverse coil 51 is energized instead. The resulting magnetic field is substantially orthogonal to that provided by the axial coil 50. The signals generated by the Y and Z pickup coils 56, 58 then depend primarily upon the relative displacement of the coil 51 around the axis 22. Because the coil 51 is mounted in fixed relationship to the piercing point 24, the displacement of the point is indicated by the relative magnitude of the respective signals from the respective Y and Z coils as detected by the respective synchronous detectors 68 and 74 and, hence, is indicated on the display 64. This enables the operator to position the tool 16 about its axis by controlling the position of the vanes 26 and thereby cause the tool 16 to advance in a desired direction relative to its axis 22. The feedback by way of the controller circuit 80 is not used in this mode, as the signal from the X coil 54 is near zero in this mode.
The present invention is useful in a simple form when it is desirable simply to keep the tool on a straight course. This is achieved simply by directing the tool 16 toward the sensing assembly 46 while keeping the outputs picked up by the Y and Z coils 56, 58 nulled. As mentioned above, it is possible to deviate to avoid obstacles and then return to the course. This is facilitated by keeping track of where the tool is at all times. This requires a measurement of the tool advance within the borehole. Although this is indicated to a degree by the power required to maintain constant the output of the X coil 54, it is more accurate to measure x displacement along the borehole more directly by measuring the length of lines 53 fed into the borehole or by a distance indicating potentiometer 84 tied to the tool 16 by a line 86. This provides a signal on a line 88 indicating displacement and incremental displacement of the tool 16 within the borehole. This information, in combination with the signals from the Y and Z coils 56, 58, permits the operator to keep track of the location of the tool at all times.
When distance is kept track of and position is determined, it is possible by more sophisticated electronics to operate with the sensing assembly in the input pit 34, particularly if the tool 16 is kept substantially on the x axis. For example, if the tool is allowed to progress a substantial distance from the desired axis, the angle B becomes significant and a more complicated set of relationships applies than when the size of the angle B is near 0 and its cosine 1. That is, Equation (4) may not be simply approximated. In this case, it will be necessary to continuously develop the position of the tool in order to provide accurate data on its location. In this case, the initial tool orientation is determined by means of the sensor coils. Then the tool is allowed to advance an incremental distance, which is also measured. The new location is then determined based on the initial angle and the incremental amount of progress, an integration process. This process is continuously repeated to allow continuous determination of the position of the tool.
Other modifications of the present invention are also possible. For example, the sensing assembly 46 may be moved from place to place or its orientation charged during boring in order to change course. Also the sensor coils can be located on the tool and the source coils placed in either pit. It is also within the scope of the present invention to provide sensors on the tool 16 for sensing obstacles, hence permitting control of the direction of tool advance to avoid the obstacles.
Other types of boring or drilling systems can be used in conjunction with the present invention, such as hydraulic percussion tools, turbo-drill motors (pneumatic or hydraulic) or rotary-drill type tools. The important aspects of the tool are that it include some motive means and a steering mechanism that can be controlled by control signals from afar.
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A control system guides a boring tool in a borehole. The tool has a longitudinal tool axis and includes a driver for advancing the tool axially through the earth and steering mechanism for directing the motion of the tool relative to the tool axis in response to control signals. The control system includes an axial electromagnetic source for generating an axial alternating magnetic field directed along an axial source axis. A sensing assembly remote from the source means includes first and second pickup coils for sensing the alternating magnetic field. Each of the first and second pickup coils has a respective coil axis and is rigidly mounted in respect to the other with their respective axes at a substantial angle with respect to each other, defining a sensing assembly axis substantially normal to both coil axes. Each coil generates a respective null electrical signal when the lines of magnetic flux at the respective coil are normal to the respective coil axis. Either the source of the sensing assembly is rigidly mounted on the tool, preferably the source. The outputs of the sensing coils are used to determine the direction of lines of magnetic flux at the sensing assembly, and indicate the attitude of the source relative to the sensing assembly. This permits guiding of the tool by control signals sent to the tool.
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TECHNICAL FIELD
This invention relates generally to the use of novel compounds as acid gas scrubbing solutions. More specifically, the invention relates to the use of substituted heterocyclic amines and polyamine compounds in industrial processes to remove acidic contaminants from natural and industrial fluid streams, such as natural gas, combustion gas, synthetic gas streams, and hydrocarbon fluids. The invention has particular relevance to processes for removal of carbon dioxide from gas streams having sour gas impurities.
BACKGROUND
Natural gas is a mixture of gaseous hydrocarbons and non-hydrocarbon impurities and contaminants. Removal of, for example, carbon dioxide and acidic sulfide contaminants (e.g., CO 2 , H 2 S, RSH, CS 2 , COS, SO 2 , etc.) to meet quality and regulatory requirements in natural gas that is fed into distribution pipelines is a major industrial burden. Such contaminants are often corrosive and may also impair the caloric value of the gas. In addition, increasing concerns of global warming from CO 2 and other emissions has prompted significant investments into methods of capturing such contaminants more efficiently and economically.
Aqueous solutions of commonly available commodity alkanolamines are generally used as scrubbing solutions (chemical absorbents) in gas processing. The purpose of these scrubbing systems is to remove acidic contaminants from the raw gas stream. As energy sources are being depleted and environmental restrictions are tightening, the economic use of the “bottom of the barrel” in gasification processes is increasing. There are many new projects being sanctioned, most of which would need acid gas clean-up to remove contaminants during processing. Removing CO 2 from flue gases is also important for a variety of reasons, such as a secondary CO 2 market, enhanced oil recovery, and greenhouse gas reduction.
Weak organic bases, such as monoethanolamine (MEA), diethanolamine (DEA), and methyldiethanolamine (MDEA) comprise many of the typical alkanolamine solvents known in the art. MDEA is known to have advantages for CO 2 removal and other acid gas contaminants in high-pressure gas streams. The amount of energy required to regenerate the MDEA is low because it is a relatively weak base and therefore the chemical bond formed during the reaction with CO 2 is weaker than with other commonly used alkanolamines. A secondary benefit lies in the nature of the chemical bond formed during absorption. As a tertiary alkanolamine, MDEA reacts with CO 2 to form a bicarbonate ion rather than a carbamate, which results in a reaction ratio MDEA to CO 2 of 1:1. In contrast, other commonly used primary and secondary alkanolamines preferentially form a carbamate and require a reaction ratio of 2:1. The reaction between CO 2 and tertiary alkanolamines (e.g., MDEA) is typically of a greater efficiency than between CO 2 and other commonly used primary and secondary alkanolamines. These combined benefits result in a process of greater efficiency and capacity than is possible with commercial primary and secondary alkanolamines such as MEA and DEA.
A disadvantage of using tertiary alkanolamines is that CO 2 is indirectly absorbed, resulting in a weak driving force and slow rate of reaction compared to other commercial alkanolamines. In high-pressure gas contacting systems the effect of the weak driving force is minimized due to the higher fraction of CO 2 that can be achieved in the liquid resulting from the high CO 2 partial pressure in the gas above it. When gasses are contacted at low pressure, the driving force is weak as the partial pressure of CO 2 is also weak. Thus, there is no beneficial effect of pressure, and the CO 2 equilibrium established between the gas and liquid is low. Tertiary alkanolamines are not normally used in low-pressure applications because of their low equilibrium loading. Other more commonly used primary and secondary amines such as MEA and DEA, which are stronger bases, are used in these applications due to their higher driving force and increased rate of reaction with CO 2 . In these low-pressure situations, the disadvantage of the inefficient carbamate reaction is outweighed by the greater equilibrium liquid distribution achieved.
In an effort to increase the capacity of MDEA for CO 2 at low partial pressure, a number of improvements to the basic MDEA process have been developed. These improvements typically involve the addition of small amounts of primary or secondary amines to the MDEA solution (as described in U.S. Pat. Nos. 5,209,914 and 5,366,709 and PCT Application No. WO 03/013699). The resulting mixtures are commonly described as formulated or blended MDEA with additives referred to as “catalysts,” “absorption accelerators,” or “activators” (e.g., U.S. Pat. No. 6,740,230). These additives generally function by increasing the rate of CO 2 absorption into the MDEA blend solution at low CO 2 partial pressure thereby increasing the fraction of CO 2 in the liquid as compared to the MDEA solution alone.
Although effective in the removal of CO 2 as described, the commercial application of known formulated solvents has less than ideal operating characteristics. Some of the additives used for formulating have limited solubility in MDEA, which reduces their effectiveness, and their commonly lower boiling (some are not lower) points in turn create difficulties in maintaining their concentration. Moreover, the reaction products of the additives with CO 2 are also problematic. As they are stronger organic bases than MDEA these blends have a tendency to require more energy for regeneration and their products have limited solubility. Such characteristics limit their effectiveness and the efficiency of the overall process if their concentration exceeds approximately 20% of the total amine in solution.
There thus exists an industrial need for improved compositions and methods for recovering acidic contaminants from both high and low pressure systems. A particular need exists for products having the benefits of both low-pressure equilibrium capacity of primary or secondary amines and the efficiency of tertiary amines within a single compound of reduced volatility.
SUMMARY
This invention accordingly provides novel compositions for removing carbon dioxide and acidic sulfide contaminants from fluid streams, for example, natural gas, synthesis gas, combustion gas, biogas, and other industrial fluid streams. Through this disclosure reference to gas or fluid streams is intended to encompass, without limitation, all such fluids. In a preferred embodiment, the compositions of the invention are used for removal, absorption, or sequestration of CO 2 . In other preferred embodiments, the compositions are used for removal of other acidic contaminants, including, without limitation, acidic and sulfide contaminants, such as CO 2 , H 2 S, RSH, CS 2 , COS, and SO 2 .
In an aspect, the invention is an absorbent liquid composition for absorbing acidic contaminants from fluid streams in an industrial process. The composition includes at least one absorbent component having the following general formula (1).
R 1 is H, alkyl, aminoalkyl, or structure (2). Preferably, if R 1 is H, then at least one of R 2 , R 3 , R 4 , or R 5 is not H, and if R 1 is structure (2), then at least one of R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , or R 9 is not H. R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , and R 9 are independently H, alkyl, or aminoalkyl, and each m, n, and o are independently 0, 1, or 2 and p and q are independently 0, 1, 2, 3, or 4.
In another aspect, the invention is an absorbent liquid composition for absorbing acidic contaminants from fluid streams in an industrial process. The composition includes at least one absorbent component having the following general formula (3).
R 1 is H, alkyl, or structure (2). Preferably, if R 1 is H, then at least one of R 2 , R 3 , R 4 , R 5 , R 10 , or R 11 is not H, and if R 1 is structure (2), then at least one of R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , or R 11 is not H. R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , and R 11 are independently H, alkyl, or aminoalkyl; each m, n, and o are independently 0, 1, or 2; and k is an integer from 2 to 6.
In another aspect, the invention is a process for reducing acidic contaminants in an industrial fluid stream. The process includes contacting the fluid stream with the described composition to form a washed fluid stream and a rich acid gas scrubbing liquid. At least a portion of the composition including at least a portion of the described absorbent component(s) is regenerated from the rich acid gas scrubbing liquid.
It is an advantage of the invention to provide a novel composition having a specific molecular structure that offers reduced volatility and a working capacity for acidic contaminants greater than commonly used alkanolamine solvents in both low and high-pressure environments.
It is another advantage of the invention to provide a novel composition that reduces acidic contaminants in natural, synthesis, and flue gases and has an increased liquid capacity for acidic contaminants at low gas pressure.
An additional advantage of the invention is to provide a novel composition that reduces acidic contaminants in natural, synthesis, and flue gases and has reduced energy of regeneration.
Another advantage of the invention is to provide a novel composition that reduces acidic contaminants in natural, synthesis, and flue gases and has increased depth of removal.
It is a further advantage of the invention to provide a novel composition that reduces acidic contaminants in natural, synthesis, and flue gases and has improved stability in the process compared to current solvents.
It is yet another advantage of the invention to provide a novel composition that reduces acidic contaminants in natural, synthesis, and flue gases and has a higher boiling point resulting in minimized losses from the process and reduced corrosivity.
Additional features and advantages are described herein, and will be apparent from, the following Detailed Description, Examples, and Figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a simplified process diagram demonstrating the configuration of the equipment in a typical amine solvent wash system.
FIG. 2 shows the common commercially available CO 2 absorbents used for the comparative testing discussed in Example 1.
DETAILED DESCRIPTION
The following definitions are intended to be clarifying and are not intended to be limiting.
“Alkyl” refers to a monovalent group derived from a straight or branched chain saturated hydrocarbon by the removal of a single hydrogen atom. Representative alkyl groups include methyl; ethyl; n- and iso-propyl; n-, sec-, iso-, and tert-butyl; C 5 to C 12 groups; eicosanyl (C 20 ); heneicosanyl (C 21 ); docosyl (behenyl, C 22 ); tricosanyl (C 23 ); tetracosanyl (C 24 ); pentacosyl (C 25 ), 3-, 7-, and 13-methylhexadecanyl; and the like. Preferred alkyls include methyl, ethyl, propyl, isopropyl, butyl, and isobutyl.
“Aliphatic amine” and/or “aminoalkyl” refers to an alkyl group having one or more amino substitutions or an amino group having multiple alkyl substitutions. Representative aminoalkyls include aminomethyl, dimethylaminomethyl, diethylaminomethyl, 2-aminoethyl, 2-dimethylaminoethyl, 2-ethylaminoethyl, and the like.
“Amino” or “amine” refers to a group having the structure —NR′R″, wherein R′ and R″ are independently selected from H and alkyl, as previously defined. Additionally, R′ and R″ taken together may optionally be —(CH 2 ) k — where k is an integer of from 2 to 6. Representative amino groups include, amino (—NH 2 ), methylamino, ethylamino, n- and iso-propylamino, dimethylamino, methylethylamino, piperidino, and the like.
“Depth of removal” refers to the amount of CO 2 that escapes the absorbent solution during peak performance (i.e., CO 2 slip), and is an approximation of the efficiency of CO 2 absorption.
“Heterocyclic amine” refers to a substituted carbocyclic structure containing at least one nitrogen member in the ring.
“Working capacity” refers to the difference between rich loading and lean loading.
This invention has application in a wide array of industrial processes including gas fields (e.g., marginal, stranded, and sour gas fields), liquefied natural gas (LNG) liquefaction developments, gas-to-liquids (GTL) developments, synthesis gas, and for the removal of CO 2 from combustion gases. The disclosed composition may be used in any industrial process, such as single or multi-injection, known in the art or in any specialized high-pressure processes, such as those described in U.S. Pat. No. 6,497,852, “Carbon Dioxide Recovery at High Pressure” and U.S. Pat. No. 7,481,988, “Method for Obtaining a High Pressure Acid Gas Stream by Removal of the Acid Gases from a Fluid Stream,” and in PCT patent application no. WO2007077323A1, “Method for Deacidifying a Gas with a Fractionally-Regenerated Absorbent Solution with Control of the Water Content of the Solution.”
Referring to FIG. 1 , an exemplary production process (typically found in natural gas processing) where this invention has utility is shown. Production process 100 includes raw gas inlet 105 where gas is contacted counter currently (typically at pressures greater than atmospheric) with a lean solvent solution (i.e., containing very low concentrations of acidic contaminants) in absorber column 110 . The rich solvent solution (i.e., containing high concentrations of acidic contaminant(s) absorbed from the feed gas) drains out of absorber column 110 and passes via a pressure reduction valve (not shown) to rich amine flash drum 115 where co-absorbed volatile hydrocarbons and a portion of the absorbed acid gas contaminate is flashed from the solvent and removed into a vapor discharge stream from the drum.
Treated gas outlet 120 contains gas exiting the top of absorber column 110 , treated and freed of acid gas contaminant(s). The rich amine solvent exits rich amine flash drum 115 and proceeds through rich/lean amine exchanger 125 , where it is heated, and then into the top of regenerator column 130 , where the acid gas contaminant(s) is separated from the rich solution at low pressure and high temperature as the solvent flows down the column. The rich solvent is stripped in the column by a countercurrent steam flow produced in amine reboiler 135 at the base of the column. The hot regenerated solvent accumulates at the base of the column and the stripped contaminant(s) gasses exit the top of the column with the stripping steam.
Steam and solvent vapor exiting the top of regenerator column 130 enters acid gas condenser 140 . Resulting liquids are collected in reflux drum 145 for circulation back to the top of the regenerator column through reflux circulation pump 165 . The regenerated hot lean solvent is pumped from the base of regenerator column 130 via rich/lean exchanger 125 (through lean amine circulation pump 160 ) and lean amine cooler 150 back into the top of absorber column 110 (through lean amine pressure pump 170 ), where the cycle is repeated. Filtration of lean solvent at lean amine filter 155 keeps it clear of solids and contaminants including degradation products caused by adverse components of the raw feed gas stream. It should be appreciated that filtration could take place an multiple and various locations in the process.
In one embodiment, the composition of this invention includes at least one substituted cyclic diamine component (as shown in structure (1) above). In a preferred embodiment, the composition of this invention includes substituted piperazine moieties with substitution at the 1 and/or 4 nitrogen positions of the piperazine ring. In other embodiments, the composition includes substituted cyclic diamines having a 4- to 12-membered ring.
Exemplary structures of typical mono- or bi-substituted piperazines of the invention are shown as structure (4) below, where R 1 is H, alkyl, aminoalkyl, or structure (5) and R is structure (6) shown below.
R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , and R 9 are independently H, alkyl, or aminoalkyl, and each m, n, and o is independently 0, 1, or 2. In a preferred embodiment, if R 1 is H at least one of R 6 , R 7 , R 8 , or R 9 is not H, and if R 1 is structure (5) at least one of R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , or R 9 is not H.
In additional embodiments, the composition of the invention includes a bisubstituted aminopiperazine, which may be symmetric or asymmetric. The substitutions are typically primary linear amines, such as ethylamine or propylamine; secondary linear amines, such as N-methyl-ethylamine; branched amines, such as 2-aminopropyl, 2-aminobutyl, and 3-aminobutyl; and linear alkyl groups. In a preferred embodiment, R 1 is a linear amine and R is a branched amine. It should be appreciated that although the symmetrical structures are proficient CO 2 absorbents, significant advantages exist in utilizing the asymmetrical variants (i.e., where one of the substituents is a branched amine and the other is a linear amine or linear alkane).
Structure (7) below illustrates a representative structure for the bisubstituted piperazine embodiment of the invention. R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , and R 9 are independently H, alkyl, or aminoalkyl. Preferred alkyls include methyl, ethyl, propyl, isopropyl, butyl, and isobutyl. Preferred aminoalkyls include 2-aminopropyl, 2-aminobutyl, aminoethyl, and aminopropyl. In a preferred embodiment, at least one of R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , or R 9 is not H. The value of each m, n, and o are independently 0, 1, or 2.
Representative monosubstituted piperazines include 2-aminopropyl-piperazine, 2-aminobutyl-piperazine, 1-acetylpiperazine, and 1-formylpiperazine. Representative examples of typical bisubstituted piperazines include 1,4-bis-(2-aminopropyl)-piperazine; 1,4-bis-(2-aminobutyl)-piperazine; 1,4-bis-(3-aminobutyl)-piperazone; 1,4-bis-(N-methyl-aminoethyl)-piperazine; 1-(2-aminobutyl)-4-methylpiperazine; 1-(2-aminopropyl)-4-methylpiperazine; and 1-(2-aminopropyl)-4-ethylpiperazine; 1-aminoethyl-4-(2-aminobutyl)-piperazine; 1-aminoethyl-4-(2-aminopropyl)-piperazine; 1-aminopropyl-4-(3-aminobutyl)-piperazine; 1-aminoethyl-4-(N-methyl-aminoethyl)-piperazine; and the like.
In yet another embodiment, the composition of the invention includes a linear or branched polyamine. Structure (8) illustrates a representative structure for this embodiment.
In an embodiment, R 1 is H, alkyl, or structure (9). Preferably, if R 1 is H and at least one of R 2 , R 3 , R 4 , R 5 , R 10 , or R 11 is not H, and if R 1 is structure (9), then at least one of R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , or R 11 is not H.
In another embodiment, R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , and R 11 are independently H, alkyl, or aminoalkyl. Preferred alkyls are methyl, ethyl, propyl, isopropyl, butyl, and isobutyl. Preferred aminoalkyls are 2-aminopropyl, 2-aminobutyl, aminoethyl, and aminopropyl. Each m, n, and o are independently 0, 1, or 2 and k is an integer from 2 to 6. Preferably, k is from 2 to 4.
In one embodiment, the composition of the invention includes an absorbent component of the formula illustrated in structure (I).
In another embodiment, the composition of the invention includes an absorbent component of the formula illustrated in structure (II).
In an additional embodiment, the composition of the invention includes an absorbent component of the formula illustrated in structure (III).
In yet another embodiment, the composition of the invention includes an absorbent component of the formula illustrated in structure (IV).
In another embodiment, the composition of the invention includes an absorbent component of the formula illustrated in structure (V).
In another embodiment, the composition of the invention includes an absorbent component of the formula illustrated in structure (VI).
In a further embodiment, the composition of the invention includes an absorbent component of the formula illustrated in structure (VII).
In another embodiment, the composition of the invention includes an absorbent component of the formula illustrated in structure (VIII).
In another embodiment, the composition of the invention includes an absorbent component of the formula illustrated in structure (IX).
In another embodiment, the composition of the invention includes an absorbent component of the formula illustrated in structure (X).
In another embodiment, the composition of the invention includes an absorbent component of the formula illustrated in structure (XI).
In another embodiment, the composition of the invention includes an absorbent component of the formula illustrated in structure (XII).
In another embodiment, the composition of the invention includes an absorbent component of the formula illustrated in structure (XIII).
In another embodiment, the composition of the invention includes an absorbent component of the formula illustrated in structure (XIV).
In another embodiment, the composition of the invention includes an absorbent component of the formula illustrated in structure (XV).
In another embodiment, the composition of the invention includes an absorbent component of the formula illustrated in structure (XVI).
In another embodiment, the composition of the invention includes an absorbent component of the formula illustrated in structure (XVII).
In another embodiment, the composition of the invention includes an absorbent component of the formula illustrated in structure (XVIII).
In another embodiment, the composition of the invention includes an absorbent component of the formula illustrated in structure (XIX).
In another embodiment, the composition of the invention includes an absorbent component of the formula illustrated in structure (XX).
In another embodiment, the composition of the invention includes an absorbent component of the formula illustrated in structure (XXI).
In another embodiment, the composition of the invention includes an absorbent component of the formula illustrated in structure (XXII).
In yet another embodiment, the composition of the invention includes an absorbent component of the formula illustrated in structure (XXIII).
In yet another embodiment, the composition of the invention includes an absorbent component of the formula illustrated in structure (XXIV).
The composition of the invention may also include derivatives and/or salts of the disclosed structures. Representative derivatives include carbonates, bicarbonates, carbamates, ureas, and amides. Representative salts include all inorganic, mineral, and organic salts.
It is the intent of this invention to use the disclosed structures in a multitude of compositions including single or multiple component solutions in water or as combined with other acid gas solvent components such as tetramethylene sulfone (i.e., Sulfolane), MDEA, DEA, MEA, and the like in water and/or other mutual solvents.
For example, single and multiple component solutions range from about 0.01 to about 100 wt % actives or from about 1 to about 75 wt % actives and include the use of solvents, such as water, alcohols, polyols, other acid gas solvents, and organic solvents. In a preferred embodiment, the composition includes about 10 to about 75 wt % or from about 40 to about 50 wt % actives. Additionally, the composition generally includes an amount of solvent in the range of 0 to 99.09 wt %, depending upon the amount of actives.
The scrubbing liquid used in the composition of the invention may also include, for example, one or more of the following components: aminoethyl-piperazine; 2-aminoethyl-piperazine; 2-aminopropyl-piperazine; 2-aminobutyl-piperazine; 1-acetylpiperazine; 1-formylpiperazine; 1,4-bis-aminoethyl-piperazine; 1,4-bis-aminopropyl-piperazine; 1,4-bisaminobutyl-piperazine; 1,4-bis-(2-aminopropyl)-piperazine; 1,4-bis-(2-aminobutyl)-piperazine; 1,4-bis-(N-methyl-aminoethyl)-piperazine; 1-(2-aminobutyl)-4-methylpiperazine; 1-(2-aminopropyl)-4-methylpiperazine; 1-(2-aminopropyl)-4-ethylpiperazine; 1-aminoethyl-4-(2-aminobutyl)-piperazine; 1-aminoethyl-4-(2-aminopropyl)-piperazine; 1-aminoethyl-4-(N-methyl-aminoethyl)-piperazine; 2-morpholinoethanamine; 2-aminopropyl-morpholine; 2-(1H-imidazol-1-yl)ethanamine; 2-aminopropyl-piperidine; 2-aminopropyl-pyrolidine; N1-(2-aminopropyl)butane-1,4-diamine; N1-(3-aminopropyl)propane-1,2-diamine; water; sulfolane, N-methylpyrrolidone; N-alkylated pyrrolidones, piperidones and morpholines corresponding to the foregoing; methanol; mixtures of dialkyl ethers of polyethylene glycols; C 1 to C 4 dialkylether monoethylene glycols; C 1 to C 4 monoether monoethylene glycols; C 1 to C 4 dialkylether poly ethylene glycols; C 1 to C 4 monoether polyethylene ethylene glycols; C 1 to C 4 ; ethylene glycol; diethylene glycol; triethylene glycol; N,N-dimethyl formamide; N-acetyl morpholine; N-formyl morpholine; N,N-dimethyl imidazolidin-2-one; N-methyl imidazole; and the like.
In another embodiment, the composition of the invention may also include other components. Representative other components include blends of amines, activators, antifoaming agents, co-absorbents, corrosion inhibitors, solvents, coloring agents, the like, and combinations thereof. Representative examples include alkanolamines; cyclotetramethylene sulfone and its derivatives; aliphatic acid amines such as acetyl morpholine or N-formyl morpholine; alkali metal compounds which provide alkaline hydrolysis products, such as alkali metal hydrolysis and hydrocarbonates; aliphatic and cycloaliphatic mono- and diamines, such as triethylene diamine, dicyclohexyl amine, N-ethyl-cyclohexylamine, and N,N-diemthylcyclohexylamine; the like; and combinations thereof.
In another embodiment, coabsorbents include one or more components selected from calcium oxide, calcium lignosulfonate, calcium silicate hydrates, calcium hydroxide, calcium carbonate, calcium bicarbonate, sodium carbonate, sodium bicarbonate, trona, sodium sesquicarbonate, soda ash, nacholite, sodium aluminate, metal oxides, and the like.
Activators and coabsorbents are preferably present in the composition of the invention from about 0.01 to about 90 wt %, more preferably from about 1 to about 50 wt %, and most preferably from about 1 to about 25 wt % (wt % based on the weight of total actives).
In a further embodiment, the invention is a process for reducing acidic contaminants in an industrial fluid stream. The fluid stream is contacted with the disclosed composition to form a washed fluid stream and a rich acid gas scrubbing liquid. Typically, the composition is contacted with the gas stream at a temperature ranging from about 0 to about 200° C. In certain cases, this temperature range may be from about 0 to about 100° C. or from about 20 to about 65° C. Industrial processes generally run at a pressure ranging from about 0 to about 200 atm, from about 0 to about 100 atm, from about 0 to about 70 atm, from about 0 to about 50 atm, from about 0 to about 25 atm, from about 0 to about 10 atm, or from about 1 to about 5 atm during the time when the composition is contacted with the fluid stream. U.S. Pat. No. 4,556,546“Bis Tertiary Amino Alkyl Derivatives as Solvents for Acid Gas Removal from Gas Streams” discloses pressure ranges from 4 to 70 atm. Canadian patent application no. 2,651,888, “Carbon Dioxide Absorbent Requiring Less Regeneration Energy” discloses pressures from 1 to 120 atm. It should be appreciated that this invention is operable in any of these or other pressure ranges encountered in the relevant art.
The rich acid gas scrubbing liquid is further processed through a regeneration system where at least a portion of the composition including at least a portion of the absorbent compound(s) contacted with the fluid stream are regenerated. The regeneration step normally takes place at a higher temperature than absorption (depending on the particular industrial process), usually at a temperature ranging from about 0 to about 500° C., from about 20 to about 250° C., or from about 50 to about 150° C. The pressure range for the regeneration step is normally from about 0 to about 10 atm or from about 1 to about 5 atm. In certain cases, the regeneration step may be carried out via a steam-assisted reboiler. Regeneration may also be carried out via a fractional regeneration process (e.g., WO 2007/077323, “Method for Deacidifying a Gas with a Fractionally-Regenerated Absorbent Solution with Control of the Water Content of the Solution”).
The foregoing may be better understood by reference to the following examples, which are intended for illustrative purposes and are not intended to limit the scope of the invention.
Example 1
The testing in this Example was used as a means of screening potential acidic contaminant scavengers and also to confirm the performance of existing commercially available scavengers. The test was designed to determine the maximum capacity of an amine solvent in absorbing acidic gases. Different amine solvents were compared. The amine solvents were saturated with acidic gases at a constant pressure and temperature until no more gas was able to be absorbed. The difference between the rich and lean loadings was used to determine the working capacity. The test was designed to regenerate the solvent by boiling to remove the acidic gases so that the lean loading of CO 2 in an amine solvent could be determined.
Solvent performance was characterized by liquid loading at equilibrium with defined composition gas mixtures at simulated amine contactor and regenerator conditions relative to industry benchmarks
To highlight the advantages of the disclosed novel amines, several specific samples were benchmarked against common commercial CO 2 absorbents (such as methyldiethanolamine (MDEA), 33.8/6.2 methyldiethanolamine/piperazine (DMDEA), diglycolamine (DGA), monoethanolamine (MEA), aminoethyl-piperazine (AEP), and bisaminopropylpiperazine (BAPP), illustrated in FIG. 2 ) using a laboratory-scale fixed bed absorption cell and a batch reboiler. The “Sorbent” numbers indicated in Table 1 correspond to the structure numbers above. The equilibrium saturation test to determine the rich loading (weight % CO2 absorbed by fresh sorbent) was run by exposing an aqueous solution of the absorbent at 40° C. to 30 psi of CO 2 until saturation was reached. The lean loading (weight % CO 2 remaining associated with the absorbent after regeneration) was determined by refluxing the aqueous solution of the absorbents for two hours at atmospheric pressure. The working capacity is defined as the rich loading minus the lean loading. It is the working capacity that most accurately reflects the capacity of the chemical to absorb CO 2 under process conditions. The results of this evaluation are reported in Table 1.
To determine rich loading, the equipment consisted of a high pressure gas panel that was capable of receiving supplies of 100% CO 2 , CO 2 /N 2 mixtures and CO 2 /H 2 S/N 2 mixtures. The chosen gas was fed via a mass flow controller (Sierra series 100 mass flow controller, available from Sierra Instruments, Inc. in Monterey, Calif.) to the reaction vessel. A gas totalizer (a Sierra Compod) attached to the mass flow controller measured the volume of gas used.
Once the appropriate gas cylinder valve and regulators were opened, the recirculating bath was set to a temperature of 40° C. A 200 ml glass reaction vessel was attached to the head of a Buchi Picoclave. The inlet and outlet valves to the reaction vessel were closed and the inlet pressure regulator was set to 30 psi. The gas mixture was set to 100% CO 2 and the flow rate was set to 0.5 liters/min. After allowing the gas pressure to build to 30 psi at the reactor inlet, the amine solution was prepared at the concentration indicated in Table 1 and, after being brought to the same temperature as the reaction vessel, was added to the reaction vessel and stirred at 1,000 rpm.
The inlet valve was opened and the reactor pressure was allowed to equilibrate to 30 psi. When the pressure in the reactor reached 30 psi, the inlet valve was closed the inlet valve and the gas flow was shut of The volume in the reactor vessel was recorded. Gas flow was resumed after 5 minutes and continued until the pressure equalized to 30 psi. This procedure was repeated until no additional CO 2 was absorbed as measured by the final volume. The wt % rich loading of the amine was calculated from the final volume of CO 2 absorbed.
To determine lean loading, the amine composition to be regenerated was poured into a 250 ml 3-neck flask equipped with mechanical stirring and a chilled condenser (8° C.). The amine solution was slowly heated to 150° C. to help avoid a sudden release of gas which would have caused the solution to foam. The solution was refluxed for 2 hours and then cooled to room temperature. The lean loading of the amine was determined via a standard barium chloride back titration.
To determine depth of removal, a mass flow controller (Sierra series 100 mass flow controller) was used to control the flow of gas through the reactor vessel. The chosen gas was fed via the mass flow controller to the saturation vessel (which contained deionized water) and then into the reaction vessel. From the reaction vessel, the gas was fed via a backpressure regulator through a Dreschel bottle containing ethylene glycol and a drying tube containing silica gel to the CO 2 analyzer. The CO 2 analyzer (Signal 7000FM CO 2 analyzer) recorded the concentration of CO 2 flowing through it. The recirculating bath was set to the required temperature of 40° C. The 200 ml glass reaction vessel was fitted to the head of a Buchi Picoclave. A Dreschel bottle containing ethylene glycol and a drying tube containing silica gel was connected to the gas line prior to the CO 2 analyzer, and the backpressure regulator was set to 90 psi. The gas mixture (25% CO 2 /75% N 2 ) and the flow rate (0.45 liters/min) were then set and allowed to stabilize for 30 minutes. The amine solution was prepared at the concentrations indicated in Table 1 and heated as above. The amine was then added to the reaction vessel and the stirrer was set to 1,000 rpm. The downstream regulator was closed and the data recording began. The gas flow was allowed to continue until equilibrium was reached ˜3 hrs. At the end of the run, the gas flow was stopped, the inlet valve to the reaction vessel was closed, and the data recording was stopped.
TABLE 1
NPX Amines vs. Common Absorbents
Rich
Rich
Lean
Lean
Working
Working
Depth of
Sorbent
MW
Wt. % (Aq)
Loading
Mole Ratio
Loading
Mole Ratio
Capacity
Mole Ratio
Removal
XXII
145.25
43.5%
17.64%
1.63
1.97%
0.15
15.67%
1.41
0.00%
XXI
131.21
39.3%
17.54%
1.61
2.21%
0.17
15.33%
1.37
NA
XIII
157.26
40.0%
13.58%
1.40
0.09%
0.01
13.49%
1.39
0.41%
XI
186.3
40.0%
13.28%
1.62
0.19%
0.02
13.09%
1.59
0.10%
X
200.32
40.0%
11.31%
1.45
0.22%
0.03
11.09%
1.42
0.15%
VI
157.26
40.0%
12.74%
1.30
0.04%
0.00
12.70%
1.30
0.18%
IV
200.32
40.0%
11.78%
1.52
0.20%
0.02
11.58%
1.49
0.24%
II
200.32
40.0%
13.27%
1.74
0.06%
0.01
13.21%
1.73
NA
I
228.38
40.0%
11.79%
1.73
0.00%
0.00
11.79%
1.73
0.35%
MDEA
119.16
40.0%
10.88%
0.83
0.00%
0.00
10.88%
0.83
1.63%
DMDEA
114.41
40.0%
11.27%
0.83
0.03%
0.00
11.24%
0.82
0.35%
DGA
105.14
40.0%
9.43%
0.62
0.13%
0.01
9.30%
0.61
0.11%
MEA
61.08
35.0%
13.50%
0.62
1.41%
0.06
12.09%
0.55
0.00%
The tested amines on average absorbed about 1.5 moles of CO 2 per mole of absorbent compared to less than 1 mole of CO 2 per mole of the common absorbents. Although not all the tested amines outperformed the common absorbents, Sorbents II, VI, XI, XIII, XXI, and XXII showed a significant increase in working capacity (5 to 30% increase based on MEA). These amines, with the exception of Sorbents XXI and XXII, also have a significantly lower lean loading than MEA.
The boiling points of the disclosed amines range from about 200 to about 280° C. at 1 atm (compared to MEA at 170° C. and 1 atm). Such higher boiling points help significantly reduce the losses and potential environmental releases currently associated with the volatility of MEA and also help to prevent CO 2 contamination during solvent regeneration. Initial laboratory stability testing has indicated that unlike MEA, which is known to degrade rapidly under process condition, the disclosed amines are highly robust at simulated process conditions showing no signs of degradation.
To further highlight the utility of the tested amines for carbon capture, a 25% CO 2 gas stream at 90 psi was passed through the absorbents at 40° C. until they reached saturation and the depth of removal was recorded. Importantly, the depth of removal for many of the tested amines approached 0%, an indication that they are highly efficient at CO 2 capture as shown in Table 1.
Example 2
Although a reduction in the lean loading of branched compounds over linear compounds would have been expected, the select group of molecules tested showed a unique increase in the working capacity of the branched targets (Table 2). The “Sorbent” numbers indicated in Table 2 correspond to the structure numbers above. This unusual reactivity is particularly evident when comparing the linear BAPP to the branched Sorbent II. The two molecules are identical in molecular weight and were tested under identical conditions; however, Sorbent II shows a 9.5% increase in working capacity. This unexpected and surprising increase in capacity is thought to occur via a change in the mechanism by which the amine reacts with CO 2 . It has been proposed that the linear amine favors direct reaction with the CO 2 to form the carbamate, and the branched amine favors (similar to tertiary amines) indirect reaction with the CO 2 to form a bicarbonate salt. Thus, the reaction between CO 2 and the branched amines are of greater efficiency.
TABLE 2
Branched vs. Linear
Working
Lean
Branched/
Mole
Mole
%
Sorbent
Linear
MW
Wt. % (Aq)
Ratio
Ratio
Increase
XIII
Branched
157.26
40.00%
1.39
0.01
17.80%
VI
Branched
157.26
40.00%
1.30
0.00
10.17%
AEP
Linear
129.20
40.00%
1.18
0.05
0.00%
II
Branched
200.32
40.00%
1.73
0.01
9.49%
I
Branched
228.38
40.00%
1.73
0.00
9.49%
BAPP
Linear
200.32
40.00%
1.58
0.14
0.00%
XXII
Branched
145.25
43.50%
1.41
0.15
12.80%
XXI
Branched
131.21
39.30%
1.37
0.17
9.60%
DETA
Linear
103.17
30.90%
1.25
0.19
0.00%
Example 3
This Example compared the absorption data of AEP and Sorbents VI and XIII. The testing revealed that alkyl substitution of one of the piperazine nitrogens with small alkyl groups (such as methyl and ethyl) afforded an unexpected increase in the capacity of the sorbent (Table 3). The “Sorbent” numbers indicated in Table 3 correspond to the structure numbers above. Sorbents VI and XIII showed an increase in capacity over the linear AEP, but unlike Sorbents I and II, which had an equal increase regardless of the length of the alkyl branch (ethyl vs. methyl), Sorbent XIII showed a significant increase in capacity over Structure VI.
TABLE 3
Alkyl Substitution of Piperazine
Working
Lean
Branched/
Mole
Mole
%
Sorbent
Linear
MW
Wt. % (Aq)
Ratio
Ratio
Increase
XIII
Branched
157.26
40.00%
1.39
0.01
17.80%
VI
Branched
157.26
40.00%
1.30
0.00
10.17%
AEP
Linear
129.20
40.00%
1.18
0.05
0.00%
Example 4
This Example illustrates that absorbents with asymmetrical substitution (e.g., a branched amine and a linear amine) demonstrated reduced depth of removal with little to no penalty in terms of working capacity and lean loading (Table 4). The “Sorbent” numbers indicated in Table 4 correspond to the structure numbers above.
TABLE 4
Asymmetrical Substitution
Working
Lean
Depth of
Sorbent
MW
Wt. % (Aq)
Mole Ratio
Mole Ratio
Removal
XI
186.3
40.0%
1.59
0.02
0.10%
X
200.32
40.0%
1.42
0.03
0.15%
IV
200.32
40.0%
1.49
0.02
0.24%
I
228.38
40.0%
1.73
0.00
0.35%
BAPP
200.32
40.0%
1.58
0.14
0.16%
All of the compositions and methods disclosed and claimed herein can be made and executed without undue experimentation in light of the present disclosure. While this invention may be embodied in many different forms, there are described in detail herein specific preferred embodiments of the invention. The present disclosure is an exemplification of the principles of the invention and is not intended to limit the invention to the particular embodiments illustrated.
Any ranges given either in absolute terms or in approximate terms are intended to encompass both, and any definitions used herein are intended to be clarifying and not limiting. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements. Moreover, all ranges disclosed herein are to be understood to encompass any and all subranges (including all fractional and whole values) subsumed therein.
Furthermore, the invention encompasses any and all possible combinations of some or all of the various embodiments described herein. Any and all patents, patent applications, scientific papers, and other references cited in this application, as well as any references cited therein and parent or continuation patents or patent applications, are hereby incorporated by reference in their entirety. It should also be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the invention and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims.
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This invention provides novel compositions comprising substituted polyamines as acid gas scrubbing solutions and methods of using the compositions in an industrial system. The invention relates to the use of such polyamine compounds in industrial processes to remove acidic contaminants from natural and industrial fluid streams, such as natural gas, combustion gas, natural gas, synthesis gas, biogas, and other industrial fluid streams. The compositions and methods of the invention are useful for removal, absorption, or sequestration of acidic contaminants and sulfide contaminants including CO 2 , H 2 S, RSH, CS 2 , COS, and SO 2 .
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REFERENCE TO RELATED APPLICATION
[0001] This is a continuation-in-part of application Ser. No. 09/796,177, filed Feb. 28, 2001 by the present inventor, now U.S. Pat. No. 6,553,777.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates in general to a dispensing system for use in a heating, ventilating or air conditioning (HVAC) air stream and, in particular, to a central or zoned forced air HVAC media dispensing system for dispensing water vapor and/or other water soluble air-flow borne materials.
[0004] More specifically, but without restriction to the particular embodiment and/or use which is shown and described herein for purposes of illustration, this invention relates to a user-programmable central or zoned HVAC dispensing system for introducing various media such as water vapor, fragrances or other air-treating materials to improve living and working environments. Further, the invention of this application relates to dispensing systems for HVAC applications wherein the individual user may selectively shift the range of concentrations of media according to the level of concentration perceived by the user.
[0005] 2. Description of Related Technology
[0006] The use of a humidification device for a central or zoned forced air HVAC system to improve living and working environments is known to those skilled in this art. Such systems generally comprise either passive evaporation of water from a reservoir adjacent to the HVAC air stream, or a circulating liquid retaining medium which passes in an endless path of movement through a water bath positioned within the HVAC air stream. While such systems are somewhat effective and simple, they are generally activated when an air stream is moving through the HVAC system and do not provide precise user control. If it is desired to dispense an additional medium into the air stream, the additional medium is manually added to the bath for dispensing into the air flow. Such systems consequently have wide variations in the amount of the media dispensed into the air stream which changes as the concentration of the media being dispensed varies, such as by evaporation, as well as the conditions of the ambient air.
[0007] In the parent of the present application there is provided a media dispensing system for use in HVAC applications including a central processor providing, in response to user-programmable data entry, control signals to a dispensing system for discharging a quantity of media into the air stream of the HVAC system. The media is supplied, also in accordance with user-selected inputs, from a plurality of media reservoirs to a manifold wherein the media is diluted to a level of concentration selected by the user through the data entry. The user may choose from a plurality of concentrations, e.g., five levels from lowest to highest, and the central processor controls discharge valves to provide the proper amount of media to the dilution manifold for the selected concentration. The central processor is programmed with a concentration algorithm specifying the amount of media corresponding to each selected level of concentration. For example, for user-selected concentrations or intensities of media, the proportions of media to water may be 1.3%, 3%, 5%, 10% and 20% for low, medium low, medium, medium high and high, respectively. However, there is no means for making the media concentration less than 1.3% or greater than 20% should the user desire lower or higher concentrations than those established by the concentration algorithm which is pre-programmed in the central processor.
SUMMARY OF THE INVENTION
[0008] It is therefore an object of this invention to improve central and zoned dispensing systems for dispensing materials into a HVAC air stream.
[0009] Another object of this invention is to provide a range of user-programmable operational controls for the dispensing of materials into an HVAC air stream.
[0010] A further object of this invention is to provide a user-programmable central dispensing system for dispensing and monitoring the dispensing of one or more water-soluble materials into the air stream of an HVAC system in a predetermined and programmable quantity.
[0011] A more particular object of the present invention is to provide a system for dispensing media into the air stream of an HVAC system which offers the user a greater degree of control over the concentration or intensity of the media at various specified concentration levels.
[0012] These and other objects are attained in accordance with the present invention wherein there is provided a user-programmable monitoring and dispensing system for controlling the dispensing of water vapor and various other media into an HVAC air stream in residential or commercial structures. The various media to be dispensed are preferably water-soluble, and mixed with the system water supply to be dispensed with the water vapor added to the HVAC air stream. These materials may be fragrances or aromas, intended to produce an aesthetic effect, or they can be agents capable of pesticidal, bacteriacidal, fungicidal or sporacidal effect for use as acute or prophylactic treatment for infestation.
[0013] Among the user inputs is the desired concentration or intensity (which words are used interchangeably herein) of the media in the water solution. The user may choose from, for example, five concentration levels, denoted low, medium low, medium, medium high and high. The central processor is programmed with a concentration algorithm which establishes the actual percentage of media in the solution at each level. However, particularly when the dispensed media is a fragrance, one user may perceive the concentration at the level established by the processor to be lower or higher than another user, based on their individual sense of smell and preference for the particular fragrance being dispensed. In fact, the user may prefer a concentration, at least at certain times, which is lower than the concentration at the lowest selectable level, or higher than the highest level. The present invention addresses, and successfully solves, this problem by permitting the user to change the concentration algorithm after being exposed to the concentration at the default (original) setting for a predetermined time.
DESCRIPTION OF THE DRAWINGS
[0014] Further objects of this invention, together with additional features contributing thereto and advantages accruing therefrom, will be apparent from the following description of a preferred embodiment of the present invention which is shown in the accompanying drawings with like reference numerals indicating corresponding parts throughout and which is to be read in conjunction with the following drawings, wherein:
[0015] [0015]FIG. 1 is a mechanical schematic of a preferred embodiment of the dispensing system to better illustrate the components thereof and the manner in which such components interrelate in the system operation;
[0016] [0016]FIG. 2 is a logic block diagram of the system operation;
[0017] [0017]FIG. 3 is a logic block diagram of the operation of the user interface keypad/display through which the system is programmed;
[0018] [0018]FIG. 4 is a logic block diagram of the system controls through which materials are dispensed into the HVAC air stream in response to the user-defined program inputs;
[0019] [0019]FIGS. 5 and 5A are graphs illustrating the default and user calibrated output scales, respectively, of the concentration algorithm; and
[0020] [0020]FIG. 6 is a logic block diagram of the user calibrated concentration level selection system.
[0021] These and additional embodiments of the invention may now be better understood by referring to the following detailed description of the invention wherein the illustrated embodiment is described.
DETAILED DESCRIPTION OF THE INVENTION
[0022] Throughout this description, the preferred embodiment and examples shown should be considered as exemplars, rather than limitations on the apparatus and methods of the present invention.
[0023] Referring now to the drawings, there is illustrated in FIG. 1 the various air flow components of an HVAC system and the central dispensing system of this invention. The portion of the HVAC system illustrated includes an air movement generating device, such as a blower 10 which generates an air stream which pass through duct work 11 to a desired residential or commercial space. The HVAC system includes a heat exchanger 12 positioned in the air stream path to heat the air moving through the duct 11 in response to the temperature set by a HVAC thermostat controller 20 , the input of which is entered through a user operated keypad/display unit 100 . In addition, an A/C coil 14 is positioned in the air stream to cool the temperature thereof in response to the temperature programmed through the thermostat 20 . The blower 10 , duct work 11 , heat exchanger 12 and A/C coil 14 are standard components utilized in HVAC forced air systems. Positioned down stream from the blower 10 , heat exchanger 12 and A/C coil 14 , in the direction of air movement, is a pressure or flow sensor 21 , such as available from Sensotec Inc., 2080 Arlingate Lane, Columbus, Ohio 43228, a humidity sensor 23 and a temperature sensor 25 , such as a HE-6310 Series Duct-mount humidity/temperature sensor, available from Johnson Controls, Inc., 507 East Michigan Street, Milwaukee, Wis. 53202, all of which are connected to a system central processor 50 , such as an Intel Type 8051 Microcontroller DS89C420-QCS Dallas Semiconductor Ultra High Speed 8051 Based Microcontroller PLCC Package available from Newark Electronics, 3 Marcus Boulevard, Albany, N.Y. 12205-1129, for providing air stream sensor inputs as to the air movement, moisture content of the air stream and the air stream temperature to the system central processor. Further down stream from these sensors, is a dispenser 16 which may be in the form of an ultrasonic transducer, available from Keramos Advanced Piezoelectrics, 5460 W. 84 th Street, Indianapolis, Ind. 46268 and Etalon Innovative Piezo Transducers, P.O. Box 127, Lebanon, Ind. 46052, or vaporizer through which water vapor and/or water-soluble materials, available from AromaTech Co., 130 Industrial Parkway, Somerville, N.J. 088076, are dispensed into the HVAC air stream in response to a user-defined program input to the system central processor 50 by means of the keypad/display unit 100 , such as a Type XK-5LC or Type LCD-96M Multi Menu Keypad available from FBII, 149 Eileen Way, Soyosset, N.Y. 11791-5316 or JDS Technologies, 12200 Thatcher Ct., Poway, Calif. 92064-6876. While a single dispenser 16 is illustrated, it is to be understood that a single dispensing head may be utilized as illustrated or multiple dispensing heads may be utilized with each one of the multiple dispensing heads being connected by means of a dilution manifold to each individual media reservoir. The dispensing heads may be piezo-electric ultrasonic transducers, atomizer spray nozzles or a media saturated evaporation wick. The dispenser 16 , as illustrated in FIG. 1, is shown dispensing into the main plenum of an HVAC system for a centralized effect from the medium dispensed. However, it is to be understood that separate dispensers may be utilized in various trunk ducts as well as the central plenum for dispersal of the medium into specific locations serviced by the HVAC system.
[0024] The display/HVAC thermostat portion 20 of the keypad/display unit 100 is coupled to the system central processor 50 to provide the inputs illustrated in FIG. 2 to control the heating/cooling operation of the system central processor 50 .
[0025] The system central processor 50 is connected to a suitable standard power supply 51 to provide power to the unit upon start up. At this time a thermostat control signal is sent 20 c from the system central processor 50 to actuate one or more of the blower 10 , heat exchanger 12 , or A/C coil 14 , in response to an on/off signal determined from the thermostat setting.
[0026] The system central processor 50 is programmed in the manner illustrated in FIG. 3, to control the operation of the media dispensing system on a daily basis, to control the dispensing of a selected medium or media, and to control the intensity thereof during the programmed cycle. The system operation, in response to the user-defined program inputs, and the output from various component sensors used in controlling system operations, are controlled in the manner illustrated in FIG. 4.
[0027] Referring again to FIG. 1, the input from the user-defined program keypad/display unit 100 , including the thermostat signal, is coupled 20 a to the system central processor 50 and appropriate display information is coupled 20 b from the system central processor 50 back to the keypad/display 100 to confirm that the signals input from the keypad/display unit 100 have been received and processed by the system central processor 50 . While in the preferred embodiment disclosed herein as the best mode contemplated by the inventor for practicing the invention the keypad/display unit 100 is utilized, it is to be understood that the input coupled 20 a to the dispenser system central processor 50 could be from a home automation control system commonly used to network and integrate the control and function of several subsystems in the space being controlled, with the feedback 20 b from the system central processor 50 being coupled to such an automation control system instead of a keypad/display unit 100 . A suitable home automation control system, not shown, has been found to be an Omni, Omni LT, and Omni Pro models available from Home Automation, Inc., 5725 Powell Street, Suite A, New Orleans, La. 70123.
[0028] When the HVAC system is in operation, an input 21 a will be received from the pressure or flow sensor 21 to the system central processor 50 confirming the movement of the air stream in the duct 11 , and input signals will be received 23 a from the humidity sensor 23 and from the temperature sensor 25 to provide input 25 a to the system central processor 50 as to the moisture content and the temperature of the air stream moving through the duct 11 . This information will be processed through the system central processor 50 and control 30 a the operation of a water intake control valve 30 , available from South Bend Controls, 1237 Northside Boulevard, South Bend, Ind. 46615; HydraForce, Inc., 500 Barclay Boulevard, Lincolnshire, Ill. 60069; and Deltrol Controls, 2740 South 20 th Street, Milwaukee, Wis. 53215, through which water passes from a suitable municipal or domestic supply source 32 into a dilution manifold 34 wherein water soluble media to be dispensed into the air stream are added for dilution prior to dispensing.
[0029] The water from water supply 32 is also connected to one or more media reservoir tanks, illustrated in the preferred embodiment as three reservoirs 35 a , 35 b and 35 c . These reservoirs may be either permanent containers which are refillable, or be replaceable as modular units. In addition, each reservoir 35 a , 35 b and 35 c incorporates a recognition media such as a bar code, magnetic strip or holographic symbol so that the system central processor 50 will receive a signal that the reservoir is in proper position and the information contained therein will effect display of the particular medium being dispensed on the keypad/display unit 100 . In addition, it is to be understood that the contour of each of the reservoirs may be such that when the reservoir is properly positioned, such a signal will be provided to the system central processor.
[0030] Each of the reservoirs 35 a , 35 b and 35 c preferably contain an inner bladder which effectively creates a second chamber within the media reservoir and the space around the inner bladder is connected in parallel to the water supply 32 such that the water fills the space around the bladder to displace the media contained within the reservoir towards the mixing manifold. Each of the media reservoirs is connected to the dilution manifold 34 by media output valves 36 a , 36 b and 36 c such as inert proportional valves available from the water intake control valve supplier and which are individually activated 37 a , 37 b and 37 c by the system control processor 50 to control the dispensing of water soluble media into the dilution manifold 34 from the respective media reservoirs 35 a , 35 b and 35 c . The water soluble media is mixed with water in the dilution manifold 34 and passes to the ultrasonic transducer or vaporizer 16 in response to the actuation 38 a of a dispensing control valve 38 available from the water intake control valve suppliers previously identified and operated by the system central processor 50 in accordance with the information coupled to the central system processor by the temperature and humidity sensors 25 and 23 , respectively, and the programmed input entered by the user through the keypad/display unit 100 . The intensity of the media contained within the media reservoirs may be achieved by varying the amount of media dispensed during and “on” cycle wherein the media reservoirs contain a constant concentration of the media or the quantity of the medium dispensed may be held constant with the concentration of the media being controlled by controlling the dilution of the medium in the dilution manifold 34 .
[0031] The media reservoirs 35 a , 35 b and 35 c are each provided with a sensor 39 a , 39 b and 39 c , respectively, available from Gems Sensors, 1 Cowles Road, Plainville, Conn. 06062, coupled to the system central processor 50 to monitor the level of the medium contained within each reservoir for proper dispensing of the medium contained therein. Sensors 39 a , 39 b and 39 c may be mounted directly upon the respective reservoirs, or upon the chassis or other mounting means for the reservoirs. Alternatively, instead of actively monitoring the level of the medium in the reservoirs 35 a , 35 b and 35 c , the system central processor 50 could calculate the quantity dispensed and thereby derive the amount remaining, assuming that the initial amount supplied to these reservoirs is constant, or otherwise “known” by the system central processor. The system central processor 50 can be programmed, as illustrated in FIG. 3, to dispense one or more of the media from the reservoirs 35 a , 35 b and 35 c into the dilution manifold 34 in increments stepped to vary the intensity or concentration of the media in the dilution manifold in accordance with the input to the system central processor 50 through the keypad/display unit 100 . A water supply pressure feedback input 33 a is connected to the system control processor 50 from a check valve and pressure sensor 33 , available from Sensotec Inc. 2080 Arlingate Lane, Columbus, Ohio 43228, carried in the municipal or domestic water supply line to ensure that an adequate supply of domestic water 32 at a desired pressure is available for use in the dispensing system.
[0032] Referring now to FIG. 2, there is illustrated the informational inputs that a user enters into the system through operation of the keypad/display unit 100 to control operation of the system central processor 50 to perform the desired functions. Upon initial system power-up, the user manually enters the time and date through the keypad/display unit 100 which is coupled 102 to the system central processor 50 . This information, once coupled to the system central processor 50 , will be used by the processor to accurately maintain current time in a manner known to those skilled in the art, and displayed on the keypad/display unit 100 .
[0033] The user then enters information to place the system central processor in either an “Active” or “Standby” mode. If the “Standby” mode is selected, the system central processor 100 will be idle and the keypad/display unit 100 will display that the system is in the “Standby” mode awaiting further instruction. If the user elects to operate the system, the “Active” mode is selected, displayed, and the user may elect to have the system operated in either a “Manual” or “Program” mode. If the “Manual” mode of operation is selected, the user can either elect to have the system operate in a “Default” sequence or a “Specified” sequence of operation.
[0034] In the “Default” sequence of operation, the system central processor 50 will sequentially actuate the first medium dispenser 35 a which will continue to operate to depletion. Upon depletion a signal will be sent by the sensor 39 a to the system central processor 50 which will then actuate the next available medium dispenser, e.g.: 35 b , which will continue to operate to depletion. At that time the sensor 39 b will send a signal to the system central processor 50 which will actuate the next available medium dispenser until all of the medium has been dispensed, at which time the system central processor 50 will cause a message to be displayed on the keypad/display unit 100 that the dispensers are empty and the system has been placed on “Standby”.
[0035] If the user elects to choose a “Specified” sequence rather than the “Default” sequence, the user can input a particular order by which the media will be used to depletion, by entering instructions through the keypad/display unit 100 for the system central processor 50 to start with a first programmed medium dispenser and then proceed upon depletion to a second specified medium dispenser and upon the depletion thereof to proceed to another specified medium dispenser. However, regardless of which mode of operation the user selects, in either of these modes the user is required to set the intensity level of each of the media to be discharged from the dispenser 35 a , 35 b , and 35 c into the dilution manifold 34 . The manner in which the intensity parameters are input to the system central processor 50 is illustrated in FIG. 3.
[0036] If the user chooses to operate the system in a “Program” mode; whereby individual medium and intensity parameters can be selected and set for individual days of the week, the user selects the “Program” option when the system “Active” display is presented.
[0037] Referring to FIG. 3, upon entering the “Program” mode the user is instructed to either accept or edit a previous program setting. If at this time the user elects not to enter the “Program” mode, an “Escape” instruction is provided which returns the user to the “Active” display whereby the system may be operated in the “Manual” mode or the user may return the system to the “Standby” mode. If, however, the user elects to proceed with the “Program” mode, the user must either “Accept” the previous program settings (or the factory settings if this is an initial installation) or select the “Edit” option if it is desired to make changes in the program previously entered. Throughout the operation in the “Program” mode, an “Escape” option is available to enable the user to return to the “Active” input level thereby cancelling all instructions entered to that point and the system returning to the previous program settings, or a “Menu Step Back” option is also available to permit the user to correct an entry error without losing the settings previously entered.
[0038] Upon selecting the “Edit” option, the user sequentially selects each day of the week to define the parameters of operation of the system for that day. These parameters include the time of program operation, identified as “Cycle 1”, “Cycle 2”, “Cycle 3” and “Cycle 4”. These times of operation are set for each day and may be individually accepted as presented previously, or edited. After the program cycle is selected, the particular medium, water vapor only or one of the media 35 a , 35 b , 35 c which is to be dispensed, maybe chosen. The intensity level (concentration) of the selected medium which is to be dispensed may be selected as well as the time period selected for operation during the program cycle can be chosen and entered through the keyboard/display unit 100 into the system central processor 50 . This information is sequentially entered into the system central processor 50 through the keypad/display unit 100 for each day of the week.
[0039] Although the system described above allows the user to choose from a plurality of concentration levels for each of a plurality of media, the percentage of media in the dispensed solution remains the same for each level any time the system is in use. For example, “Media A” may have a concentration of 1.3% at the “Low” setting and 20% at the “High” setting. Thus, if the user wants a concentration of Media A which is less than 1.3% or greater than 20%, this cannot be achieved with the system as described to this point. This is illustrated by the graph of FIG. 5, providing an example of the concentration algorithm, a line of constant slope, for Media A. The concentration algorithm and percentages of media at each of five intensity levels are as follows:
User-selectable Low MedLow Med MedHi High intensity levels: Media A dilution 0.5(0.5 * X) 0.5 * X X 2 * X 2(2 * X) algorithm Default value 1.3% 3% 5% 10% 20%
[0040] In the user calibration procedure of the present invention, the above algorithm is in effect when Media A is recognized by the central processor as the medium in use. At system startup, the default value at the medium intensity level, i.e., 5%, is automatically chosen. The medium, assumed in this case to be a fragrance, is dispensed at this level for a predetermined time period, e.g., one hour. At the end of that time, the display prompts the user to enter the intensity level which most closely corresponds to the user's perception of the intensity of fragrance at that time. If the user's sense of smell and personal preference for the fragrance indicate that the intensity level is in the medium-high range, the user presses the “Med/High” button on the data entry/display 100 . Doing so resets the dilution scale by relocating the default X value on the algorithm. That is, the concentration algorithm is shifted from the position shown by the dotted line in FIG. 5A (i.e., the position of FIG. 5) to the solid line position of FIG. 5A. The concentration of media is reduced at each of the five selectable intensity levels.
[0041] Using the example above, if the user rates the perceived intensity as:
Low Med/Low Med Med/High High 1. High, then the 0.31% 0.63% 1.25% 2.50% 5% resulting user- calibrated scale, for that specific fragrance would become: 2. Med/High, then the 0.63% 1.25% 3% 5% 10% resulting user- calibrated scale, for that specific fragrance would become: 3.Med, then the 1.25% 2.5% 5% 10% 20% resulting user- calibrated scale, for that specific fragrance would become: 4.Med/Low, then the 2.5% 5% 10% 20% 40% resulting user- calibrated scale, for that specific fragrance would become: 5.Low, then the 5% 10% 20% 40% 80% resulting user- calibrated scale, for that specific fragrance would become:
[0042] Once the user has calibrated the output intensity scale for a particular fragrance (or other medium) the system will apply that scale whenever that fragrance (or medium) is recognized. “Recognition” may be implemented, as described earlier herein, by incorporation in each media reservoir of machine readable indicia such as a bar code, magnetic strip, holographic symbol or RFID tag (as commonly used in retail stores for security purposes). The user may re-calibrate at any time, and the system will overwrite the former scale with the newly chosen one. The logic block diagram of FIG. 6 illustrates the sequence of steps in the calibration procedure wherein the user provides inputs based on that user's perceived (desired) intensity of the medium which is dispensed at the default level for a predetermined (default) time period.
Functional Description
[0043] Referring now to FIG. 4, the user inputs the initial information into the system central processor 50 through the keypad/display unit 100 in the manner previously described, selects the mode of operation and programs the system as desired. The temperature sensor 25 , humidity sensor 23 , flow sensor 21 , media sensors 39 a , 39 b , and 39 c , and water supply sensor 33 a all provide their respective input signals to the system central processor 50 . The keyboard/display 100 shows the status of the informational inputs. If the program cycle inputs, the operational sensor inputs and time of operation call for an activation of a dispensing sequence, dispensing operation is initiated and the keypad/display 100 shows that the system is dispensing as instructed. The selected media dispensing valve 36 a , 36 b or 36 c is opened the prescribed extent and duration. The water intake control valve 30 is opened allowing water and the selected medium to mix in the dilution manifold 34 . The dispensing control valve 38 is opened and the dispenser 16 is actuated for a time period determined by the parameters of the ambient air moving through the air duct 11 . The input from the ambient air flow sensors 21 , 23 and 25 coupled to the system central processor 50 prevent the system from dispensing media at a level beyond the capacity of the air stream flow to move the dispensed medium through the HVAC system.
[0044] Referring to FIG. 6, upon installation of a media reservoir the indicia thereon is read to indicate presence of the reservoir and identity of the medium. If the medium is recognized as one for which user-programmed functional data has previously been entered, the system proceeds to operate according to such instructions. Otherwise, the user performs, via the keypad data entry, the necessary input instructions to permit the system to operate at a default intensity level. After operation at that level for a predetermined time period, the user is prompted to enter the perceived concentration level. Stated another way, the user enters a level of intensity rating the concentration during the default period relative to the concentration which the user would prefer. This action serves to shift the concentration algorithm in the manner illustrated in FIG. 5A.
[0045] It will be understood that, although the invention has been described as having a diffuser and various sensors mounted in an air flow plenum of a heating, ventilating and/or air conditioning system, it could instead be incorporated in a console or table top humidifier located in the occupied living space with the diffuser discharging directly into the living space.
[0046] While this invention has been described in the specification and illustrated in the drawings with reference to a preferred embodiment, the structure of which has been disclosed herein, it will be understood by those skilled in the art to which this invention pertains that various changes may be made, and equivalents may be substituted for elements of the invention without departing from the scope of the claims. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed in the specification and shown in the drawings as the best mode presently known by the inventors for carrying out this invention, nor confined to the details set forth, but that the invention will include all embodiments, modifications and changes as may come within the scope of the following claims:
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A user-programmable monitoring and dispensing system for controlling the dispensing of water vapor and various other media into an HVAC air stream in residential or commercial structures. The various media to be dispensed are preferably water-soluble, and mixed with the system water supply to be dispensed with the water vapor added to the HVAC air stream. These materials may be fragrances or aromas, intended to produce an aesthetic effect, or they can be agents capable of pesticidal, bacteriacidal, fungicidal or sporacidal effect for use as acute or prophylactic treatment for infestation. The dispensing system central processor is pre-programmed with a default concentration algorithm for each media to be dispensed. The concentration of media in aqueous solution is initially controlled by this default algorithm at each of several concentration levels, from lowest to highest. After being exposed to the air containing the dispensed media at a medium concentration of the default algorithm for a default time period, the user may indicate, via a data entry/display, whether the perceived concentration is higher or lower than that desired. This input from the user to the central processor acts to replace the default concentration algorithm with a new, preferred algorithm wherein the scale of media concentration is shifted to correspond to the user's preference.
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[0001] This application claims the benefit of U.S. Provisional Patent Application No. 60/879,896, filed Jan. 11, 2007.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to medical implants. Particularly, the present invention relates to fracture plates and cages. More particularly, the present invention relates to a bone loss plate for the rigid fixation of long bone fracture where there is significant bone loss at the fracture site or bone loss gaps caused by pathological processes.
[0004] 2. Description of the Prior Art
[0005] Fracture plates and cages have been in use for years. Typically, fracture plates and cages are comprised of separate fracture plates and metallic mesh cages. Plates are used to immobilize bone fractures and to maintain alignment during the healing process. Cages have been used to make up the space in areas of bone loss due to fracture or other pathologic processes.
[0006] The main problem with conventional fracture plates is that plates cannot close gaps between the fractured ends of severely damaged bones. Bone does not heal if significant gaps exist between fracture fragments of broken or otherwise damaged opposing bone ends. If there is bone loss at the fracture site the use of a conventional plating system requires the fracture ends to be pulled together shortening the overall length of the original bone.
[0007] Alternatively, mesh cylindrical cages filled with osteogenic material may be inserted into the gap prior to assembling the plate system to the fractured bone. A drawback of conventional cages used to fill gaps in damaged bone is that the cages may migrate out of position. Additionally, conventional cages do not provide immobilization of the fractured bone nor can they maintain alignment of the fractured bone.
[0008] While these devices may be suitable in some circumstances, they are not as suitable for the rigid fixation of long bone fracture where there is significant bone loss at the fracture site or bone loss gap caused by pathological processes.
[0009] U.S. Pat. No. 4,938,768 discloses a bone gap bridging and fusing device. The bone gap bridging device includes first and second pin members adapted to be placed in axial openings formed in the opposed remaining bone portions. Each pin member includes a head and the heads of the pin members interengage one another to prevent relative rotation between the pin members. A collar telescopes over the interengaged heads to lock the pin members axially relative to one another.
[0010] This device suffers the disadvantage that tapered openings in axial alignment must be formed in the ends of the bone portions in order to receive the pin members of the device. Additionally, the collar and the pin members must have mating threads as well as set screws to fix the collar in position relative to the pin members, which adds to the cost of the device.
[0011] Therefore, what is needed is a device and method to rigidly fix a long bone fracture where there is significant bone loss at the fracture site or caused by pathological processes. What is also needed is a device and method that also fills the gap produced by the bone loss so that shortening does not occur. What is further needed is a device and method that provides immobilization and maintenance of alignment of a bone fracture while eliminating or minimizing the shortening of the bone caused by bone loss.
SUMMARY OF THE INVENTION
[0012] It is an object of the present invention to provide a device and method that rigidly fixes a long bone fracture where there is significant bone loss at the fracture site. It is another object of the present invention to provide a device and method that fills the gap produced by the bone loss so that shortening does not occur. It is a further object of the present invention to provide a device and method that provides immobilization and maintains alignment of a bone fracture while eliminating or minimizing the shortening of the bone caused by bone loss. It is still another object of the present invention to provide a device and method that combines cages designed to fit into the areas of bone loss due to severe trauma with a stability providing plate. It is yet another object of the present invention to provide a device and method that eliminates the possibility that the cage will migrate out of optimum position. It is another object of the present invention to provide a weight-bearing surface upon which the fracture ends can be seated during the healing process. It is a further object of the present invention to provide a device that has a known volume. It is an object of the present invention to provide a device that physically contains the osteogenic material placed inside it. It is still another object of the present invention to provide a device that that can fill gaps in long bones produced by pathological processes such as infections, trauma and tumors. It is yet another object of the present invention to provide a device that immobilizes the spine while filling the defects in vertebral bodies or disc spaces.
[0013] The present invention achieves these and other objectives by providing a bone loss plate having a fixation plate and a tubularly-shaped containment cage connected to the fixation plate. The fixation plate has a first plate side, a second plate side, is preferably rectangularly shaped, and has a proximal portion, a distal portion and a middle portion. The proximal and distal portions have a plurality of openings through which fasteners are positioned to fixedly attach the plate to the respective ends of the fractured bone.
[0014] The tubularly-shaped containment cage is preferably an elliptically-shaped metallic mesh basket that has a diameter approximately equal to the diameter of the fractured bone ends. The plate side of the tubularly-shaped cage is connected to the middle portion of the plate and may optionally be integrally formed into the middle portion of the plate. The tubularly-shaped cage may optionally include cage braces and, preferably, top and bottom cage braces. In the elliptically-shaped embodiment, the top and bottom cage braces are symmetrically placed along a chord line at each end.
[0015] Preferably, the tubular containment cage has a shape defined by the shape of the bone to which the bone loss plate is to be attached. Thus, the tubular containment cage is preferably customized for the installed location. It is also preferable that the ends of the tubular containment cage have a diameter about the same as the diameter of the ends of the bones to be joined. The tubular containment cage may optionally be configured to be expandable.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a perspective rear view of one embodiment of the present invention showing the bone loss plate.
[0017] FIG. 2 is a perspective front view of the embodiment in FIG. 1 showing the tubularly-shaped containment cage.
[0018] FIG. 3 is a perspective side view of the embodiment in FIG. 1 showing the mesh structure of the tubularly-shaped containment cage.
[0019] FIG. 4 is a perspective top view of the embodiment in FIG. 1 showing the inside of the tubularly-shaped containment cage.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0020] The preferred embodiment of the present invention is illustrated in FIGS. 1-4 . FIG. 1 shows a perspective back view of the bone loss plate 10 of the present invention. Bone loss plate 10 has a fixation plate 20 showing a second plate side 21 and a tubularly-shaped containment cage 40 . Fixation plate 20 has a proximal portion 22 , a distal portion 24 and a middle portion 26 . Proximal portion 22 and distal portion 24 have a plurality of fastener openings 28 . Middle portion optionally includes a cage aperture 30 and provides access to the inside of tubularly-shaped containment cage 40 .
[0021] For example, to treat a tibial fracture in an average adult male, proximal and distal portions 22 , 24 of plate 20 are typically about 4 mm. thick, about 20 mm. wide and about 40 mm. long. The plurality of fastener openings 28 in proximal and distal portions 22 , 24 also have four or more holes approximately 4 mm. in diameter through which fasteners such as, for example, screws are used to fixedly attach plate 20 to the respective fractured bone ends. The plurality of fastener openings 28 are aligned adjacent the longitudinal axis of plate 20 . Fasteners other than screws may be used to fixedly attach plate 20 to the bone. In certain clinical situations, it may be advantageous to form plate ends 32 in a curvilinear shape. In other embodiments, optional cage aperture 30 may be incorporated into the middle section 26 of plate 20 so that osteogenic material can be disposed inside tubularly-shaped cage 40 after positioning bone loss plate 10 in the bone fracture area. It should be understood that osteogenic material can also be disposed inside tubularly-shaped cage 40 before positioning bone loss plate 10 in the bone fracture area.
[0022] Turning now to FIG. 2 , there is illustrated a perspective front view of the present invention. Tubularly-shaped containment cage 40 is preferably an elliptically-shaped metallic mesh structure 42 that has a diameter approximately equal to the diameter of the fractured bone ends. The plate side of the tubularly-shaped containment cage 40 is connected to middle portion 26 of a first plate side 23 of plate 20 and may optionally be integrally formed into middle portion 26 . Tubularly-shaped containment cage 40 may optionally include one or more cage braces 50 and, preferably, top and bottom cage braces 50 . In the elliptically-shaped embodiment, the top and bottom cage braces 50 are symmetrically placed along a chord line of tubularly-shaped containment cage 40 .
[0023] Preferably, tubularly-shaped containment cage 40 is an elliptically-shaped, metallic, mesh cage that is integrally connected to middle portion 26 of plate 20 . The mesh structure 42 provides a plurality of cage wall openings 44 and is more clearly shown in FIG. 3 . The height of containment cage 40 is dictated by the length of bone that it is intended to replace. The shape of containment cage 40 is dictated by the shape of the bone requiring treatment. Thus, the shape and size of tubularly-shaped containment cage 40 is customized accordingly.
[0024] The cross-sectional shape of each end 48 , 48 ′ of the tubularly-shaped containment cage 40 is preferably an approximate mirror image of the cross-section of the respective ends of the bone that it is supporting. Containment cage 40 preferably has cage braces 50 symmetrically placed along a chord line at each end 48 , 48 ′ and preferably made of the same material as containment cage 40 . An optional feature of containment cage 40 is that it may be detachable from fixation plate 20 , a feature that would be advantageous in certain instances. In other embodiments, it is advantageous to make containment cage 40 from a material different from that of plate 20 . Containment cage 40 may optionally be expandable along its longitudinal axis. This optional feature provides a single bone loss plate 20 that is usable in situations where the bone gap varies or is adaptable for different sized bone gaps. This optional feature reduces cost by standardization.
[0025] Turning now to FIG. 4 , there is illustrated a perspective top view of the present invention. As can be seen, tubularly-shaped containment cage 40 has an internal space 52 formed by circumferential cage wall 44 . Cage braces 50 disposed at cage ends 48 , 48 ′ are more clearly shown. As previously disclosed, an osteogenic material may optionally be disposed in internal space 52 either before or after placement of bone loss plate 10 . The mesh wall structure allows bone growth to penetrate containment cage 40 during the healing process.
[0026] Bone loss plate 10 is used to treat bone pathology where a significant portion of bone is lost. The bone requiring treatment can be envisioned to have two ends, one proximal and one distal, and a gap of unspecified length between the two opposing ends. Tubularly-shaped containment cage 40 of bone loss plate 10 , being approximately concentric with the cross-sectional shape of the bone ends, is placed in the gap in the bone so that the opposing ends of the bone will be in contact and supported by the cage ends 48 , 48 ′ of containment cage 40 and optional cage braces 50 . Containment cage 40 may be filled with osteogenic material before or after positioning. When containment cage 40 is properly positioned in the gap, fixation plate 20 will lay flat along the length of the respective shafts of the pathologic bone. Fixation plate 20 is then fastened to the bone shafts by screws that are placed through fastener openings 28 in fixation plate 20 .
[0027] Although the preferred embodiments of the present invention have been described herein, the above description is merely illustrative. Further modification of the invention herein disclosed will occur to those skilled in the respective arts and all such modifications are deemed to be within the scope of the invention as defined by the appended claims.
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A bone loss plate for the rigid fixation of a bone having a bone gap where portions of the bone are absent, the plate includes an elongated fixation plate having a first plate side, a second plate side, a proximal portion, a distal portion, and a middle portion and a tubularly-shaped containment cage connected to the second plate side of the elongated fixation plate, the tubular containment cage having a length shorter than the elongated fixation plate.
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FIELD OF THE INVENTION
[0001] The present invention pertains generally to furniture manufacturing and specifically but is not limited to the making of drawer box joints.
BACKGROUND OF THE INVENTION
[0002] Drawer box joints are generally made several ways from wood of varying species or composite woods and vary from manufacturer to manufacturer. Drawer box joints generally are made from finger box joints, dovetail joints, lap joints, tongue and groove joints and other similar joints.
[0003] Drawer box joints are typically fastened together with some type of wood glue or epoxy and where the glue or epoxy is applied directly at the interface between the pieces of wood that overlap. In some cases mechanical plates are applied in addition to the glue joints. This added mechanical fastener provides additional strength to the joint and makes the joint less susceptible to mechanical stress over time. Drawer box joints with mechanical plates are much more expensive than drawers box joints without mechanical plates.
[0004] Most drawer box joints without mechanical plates are susceptible to failure in at least one or more of three possible x,y,z dimensions due to mechanical stress over time. The strength of the joint depends on the type of glue or epoxy used and the type of joint chosen. The strongest drawer box joint, a dovetail joint, may pull apart in one of the three x,y,z dimensions upon failure of the glue joint under stress. Finger box joints or tongue and groove joints may pull apart in two of the three possible x,y,z dimensions upon failure of the glue joint under stress. The weakest drawer box joint may be the lap joint or overlap joint and may pull apart in three of the possible x,y,z dimensions upon failure of the glue joint under stress.
[0005] It would therefore be advantageous to create or manufacture a drawer box joint that was not susceptible to stress or failure in any of the three possible x,y,z dimensions over time, and create a joint that dramatically increases the glued joint surface area and did not require expensive mechanical plates for additional support.
SUMMARY OF THE INVENTION
[0006] The present invention overcomes the disadvantages and limitations of previous solutions by providing a system and method for designing and manufacturing drawer box joints with improved strength and reliability under mechanical stress over time by dramatically increasing the glued surface area of the overlapping pieces of the drawer box joint, and fastening the pieces through multiple steps that prevent the movement of the joint in any of the three x,y,z dimensions in the event of a glue joint failure without the use of additional expensive mechanical plates.
[0007] One embodiment of the present invention may include a finger box joint, a round hole drilled through the top corner of the joint, a dowel peg placed into the hole in the interlocking fingers, a set of finishing nails driven into one or more sides of the interlocking fingers in the corner joint such that the finishing nails are driven into and through the dowel peg and into the opposing corner piece.
[0008] Another embodiment of the present invention may include a dove tail joint, a square or rectangular hole drilled through the top corner of the joint, a square or rectangular peg placed into the hole in the interlocking fingers, one or more screws turned into one or more sides of the interlocking fingers in the corner joint such that the screws are turned into and through the square or rectangular peg and into the opposing corner piece.
[0009] The advantages of the present invention are that it has an increased gluing surface area resulting in a much higher strength joint and results in a joint that will not fail in any one dimension of the x,y,z plane. Additional metal plates are not needed to achieve the final joint strength. In some cases the resulting joint will not have to be clamped during the cure time of the glue due to its construction.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is an illustration of prior art for a box finger joint.
[0011] FIG. 2 is an illustration of an embodiment of a finger box joint which utilizes a dowel peg and finishing nails.
[0012] FIG. 3 is an illustration of an embodiment of a left side cross section of a finger box joint in FIG. 2 which utilizes a dowel peg and finishing nails.
[0013] FIG. 4 is an illustration of an embodiment of a right side cross section of a finger box joint in FIG. 2 which utilizes a dowel peg and finishing nails.
[0014] FIG. 5 is an illustration of an alternative embodiment of a finger box joint which utilizes a square or rectangular peg and finishing nails on both sides of the joint.
[0015] FIG. 6 is an illustration of an alternative embodiment of a finger box joint which utilizes variable sized interlocking fingers, partial feed through dowel pegs and finishing nails on both sides of the joint.
[0016] FIG. 7 is an illustration of an embodiment of a left side cross section of a finger box joint in FIG. 6 which utilizes variable sized interlocking fingers, partial feed through dowel pegs and finishing nails on both sides of the joint.
[0017] FIG. 8 is an illustration of the various types of pegs that may be placed in the corner and through the interlocking fingers of the finger box joint.
[0018] FIG. 9 is an illustration of an alternative embodiment of a two piece “T” shaped interlocking corner joint which utilizes a dowel peg and finishing nails.
[0019] FIG. 10 is an illustration of an alternative embodiment of a three piece “T” shaped interlocking corner joint which utilizes a dowel peg and finishing nails.
DETAILED DESCRIPTION OF THE INVENTION
[0020] The specific embodiments of the invention are described in this section. The embodiments that follow below were selected to illustrate the various features of the invention, but should not be construed to limit the invention to the embodiments illustrated and described, as the invention is susceptible to various modifications and alternate forms. In general, the embodiments were selected to bring to light the inventive feature, aspects and components of the invention. The invention is intended to cover all variations, modifications and equivalents falling within the scope and nature of the invention as described by the claims.
[0021] The invention may be embodied as individual methods, containers, boxes, drawers or part of tables, cabinets, night stands, dressers or any type of furniture or fixture that contains a corner joint. The angle of the corner joint may be 90 degrees but is not limited to any angle including the range from 0 to 180 degrees or from 0 to −180 degrees. The corner joint may be composed of two or more interlocking pieces. In the case of two interlocking pieces, an “L” or a “T” shaped corner joint may be formed. In the case of three interlocking pieces, a “T”, “Y” or an “X” shaped corner joint may be formed. In the case of 4 interlocking pieces, an “X” shaped corner joint may be formed. The number of interlocking pieces and angle between each interlocking piece is not limited, nor is the number of geometric shapes that can be formed at the interlocking corner joint. The illustrations shown in the FIGS. 1 through 8 shows various embodiments of a two piece “L” shaped interlocking corner joint. FIG. 9 shows an alternative embodiment of a two piece “T” shaped interlocking corner joint. FIG. 10 shows an alternative embodiment of a three piece “T” shaped interlocking corner joint. Anyone skilled in the art may be able to extend the inventive concepts illustrated in FIGS. 1 through 10 to create the additional geometric shapes mentioned above or any additional geometric shape from any number of interlocking pieces. The invention may be comprised of stone, stone composite, metal, molded or formed metal, plastic, glass, wood, glue, epoxy resin, fiber glass, polymer resin, plexiglass or any formed, welded, shaped or cut material.
[0022] FIG. 1 illustrates prior art of a box finger joint 100 . The left side 101 of the box finger joint 100 is created by cutting or forming the alternating left side interlocking fingers 104 . In a similar manner, the right side 102 of the box finger joint 100 is created by cutting or forming the alternating right side interlocking fingers 103 . Subsequently the left side 101 and right side 102 are joined together and the interface between the right side interlocking fingers 103 and left side interlocking fingers 104 , are typically glued and clamped in a clamping device until dry.
[0023] FIG. 2 illustrates an embodiment 200 of the present invention showing stronger box finger joint with dowel peg and finishing nails. The left side 201 of the box finger joint 200 is created by cutting or forming the alternating left side interlocking fingers 204 . In a similar manner, the right side 202 of the box finger joint 200 is created by cutting or forming the alternating right side interlocking fingers 203 . Subsequently the left side 201 and right side 202 are joined together and the interface between the right side interlocking fingers 203 and left side interlocking fingers 204 , and are typically clamped in a clamping device. While still in the clamping device, a round hole is drilled at the top corner of 200 . The pieces can now be removed from the clamping device. Glue is placed in the drilled hole and at the interface of the right and left side interlocking fingers 203 and 204 respectively. The pieces are clamped in a clamping device and subsequently a dowel peg 206 is placed in the hole. After insertion of the dowel peg 206 , finishing nails 205 are driven into the right side interlocking fingers 203 and through the dowel peg 206 and into the left side 201 . The clamping device may be left in place until the glue has cured. Alternatively the clamping device may be removed after the box finger joint with dowel peg and finishing nails 200 is completed but prior to the glue cure time. The order in which the interlocking fingers 203 and 204 , the hole for the dowel peg 206 are formed, as well as the order of the glue application and clamping may be varied.
[0024] FIG. 3 is an illustration of an embodiment 300 of a left side cross section of the corner of the box finger joint with dowel peg and finishing nails 200 in FIG. 2 . The left side 301 is aligned so that the left side interlocking fingers 304 are perpendicular to the right side interlocking fingers 303 . The hole is drilled at the corner of 300 through the left and right side interlocking fingers 304 and 303 respectively. The location of the dowel peg 306 inserted into the hole and through 303 and 304 is shown. The finishing nails 305 may be driven into the right side interlocking fingers 303 and through the dowel peg 306 and into the left side 301 .
[0025] FIG. 4 is an illustration of an embodiment 400 of a right side cross section of the corner of the box finger joint with dowel peg and finishing nails 200 in FIG. 2 . The right side 402 is aligned so that the right side interlocking fingers 403 are perpendicular to the left side interlocking fingers 404 . The hole is drilled at the corner of 400 through the right and left side interlocking fingers 403 and 404 respectively. The location of the dowel peg 406 inserted into the hole and through 403 and 404 is shown. The finishing nails 405 may be driven into the right side interlocking fingers 403 and through the dowel peg 406 and into the left side.
[0026] FIG. 5 illustrates an alternative embodiment 500 of the present invention showing stronger box finger joint with square peg and finishing nails. The left side 501 of the box finger joint 500 is created by cutting or forming the alternating left side interlocking fingers 504 . In a similar manner, the right side 502 of the box finger joint 500 is created by cutting or forming the alternating right side interlocking fingers 503 . Subsequently the left side 501 and right side 502 are joined together and the interface between the right side interlocking fingers 503 and left side interlocking fingers 504 , and are typically clamped in a clamping device. While still in the clamping device, a square or rectangular mortise hole is drilled at the top corner of 500 . The pieces can now be removed from the clamping device. Glue is placed in the drilled or mortised hole and at the interface of the right and left side interlocking fingers 503 and 504 respectively. The pieces are clamped in a clamping device and subsequently a square or rectangular peg 506 is placed in the hole. After insertion of the square or rectangular peg 506 , finishing nails 505 are driven into the right and left side interlocking fingers 503 and 504 respectively and through the square or rectangular peg 506 and into the left and right sides 501 and 502 respectively. The clamping device may be left in place until the glue has cured. Alternatively the clamping device may be removed after the box finger joint with square peg and finishing nails 505 is completed but prior to the glue cure time. The order in which the interlocking fingers 503 and 504 , the hole for the square or rectangular peg 506 are formed, as well as the order of the glue application and clamping may be varied.
[0027] FIG. 6 illustrates an alternative embodiment 600 of the present invention showing stronger box finger joint with partial feed through dowel pegs and finishing nails. The left side 601 of the box finger joint 600 is created by cutting or forming the alternating left side interlocking fingers 604 . In a similar manner, the right side 602 of the box finger joint 600 is created by cutting or forming the alternating variable sized right side interlocking fingers 603 . Subsequently the left side 601 and right side 602 are joined together and the interface between the right side variable sized interlocking fingers 603 and left side interlocking fingers 604 is typically glued and clamped in a clamping device. While still in the clamping device, a hole is drilled at the top corner of 600 . The hole at the top corner of 600 typically may not go all the way through 600 but may stop almost half way through 600 . Glue is placed in the drilled top hole and subsequently a top side partial feed through dowel peg 606 is placed in the hole. In a similar manner, a hole is drilled at the bottom corner of 600 . The hole at the bottom of the corner of 600 typically may not go all the way through 600 but may stop almost half way through 600 . Glue is placed in the drilled bottom hole and subsequently a bottom side partial feed through dowel peg 607 is placed in the hole. After insertion of the top and bottom partial feed through pegs 606 and 607 respectively, finishing nails 605 are driven into the right and left side interlocking fingers 603 and 604 respectively and through the top partial feed through peg 606 and bottom partial feed through peg 607 and into the left and right sides 601 and 602 respectively. The clamping device may be left in place until the glue has cured. Alternatively the clamping device may be removed after the box finger joint with partial feed through dowel pegs 606 and 607 and finishing nails 605 is completed but prior to the glue cure time. The order in which the interlocking fingers 603 and 604 , the holes for the partial feed through pegs 606 and 607 are formed, as well as the order of the glue application and clamping may be varied.
[0028] FIG. 7 is an illustration of an embodiment 700 of a left side cross section of the corner of the box finger joint with partial feed through dowel pegs and finishing nails 600 in FIG. 6 . The left side 701 is aligned so that the left side interlocking fingers 704 are perpendicular to the variable sized right side interlocking fingers 703 . The hole is drilled at the corner of 700 through the left and variable sized right side interlocking fingers 704 and 703 respectively. The location of the top side partial feed through dowel peg 706 and bottom side partial feed through dowel peg 707 inserted into the top and bottom side holes respectively and through the right side variable sized interlocking fingers 703 and left side interlocking fingers 704 is shown. The finishing nails 705 may be driven into the right side variable sized interlocking fingers 703 and left side interlocking fingers 704 and through the partial feed through dowel pegs 706 and 707 and into the left side 701 and into the opposing side piece.
[0029] Alternatively the round top side and bottom side partial feed through dowel pegs 706 and 707 respectively may be replaced by but is not limited to square pegs, rectangular pegs, epoxy resin, fastening nails, staples, screws or any other type of tapered or stepped shaped peg. The appropriate top and bottom sized holes need to be first drilled to fit the screw or geometric shape of the peg chosen. In addition, the finishing nails 705 may be omitted or replaced by but is not limited to screws or other type of hole and smaller peg. Also the finishing nails 705 may only go partially through the top side and bottom side partial feed through dowel pegs 706 and 707 respectively. The right side variable sized interlocking fingers 703 and left side interlocking fingers 704 may be replaced by but is not limited to dovetail joints or any other type of full or partial interlocking finger joint. A right side cross section of 600 in FIG. 6 is not shown but should be obvious to the reader based on the previous discussion of FIG. 2 , FIG. 3 and FIG. 4 .
[0030] FIG. 8 illustrates an embodiment 800 of the present invention showing various sized and shaped pegs that may be used in place of 706 and 707 in FIG. 7 . The size and shape of the pegs may take the form but are not limited to the pegs 801 , 802 , 803 and 804 shown. 801 is an exemplary illustration of a round dowel peg. 802 is an alternative exemplary illustration of a square or rectangular peg. 803 is an alternative exemplary illustration of a variable step round peg. 804 is an alternative exemplary illustration of a tapered round peg.
[0031] FIG. 9 illustrates an alternative embodiment 900 of the present invention showing a stronger two piece “T” shaped box finger joint with dowel peg and finishing nails. The front side 901 of the box finger joint 900 is created by cutting or forming the alternating front side interlocking fingers 904 . In a similar manner, the back side 902 of the box finger joint 900 is created by cutting or forming the alternating back side interlocking fingers 903 . Subsequently the front side 901 and back side 902 are joined together and the interface between the back side interlocking fingers 903 and front side interlocking fingers 904 , and are typically clamped in a clamping device. While still in the clamping device, a round hole is drilled at the top corner of 900 . The pieces can now be removed from the clamping device. Glue is placed in the drilled hole and at the interface of the back and front side interlocking fingers 903 and 904 respectively. The pieces are clamped in a clamping device and subsequently a dowel peg 906 is placed in the hole. After insertion of the dowel peg 906 , finishing nails 905 are driven into the front side interlocking fingers 904 and through the dowel peg 906 and into the back side 902 . The clamping device may be left in place until the glue has cured. Alternatively the clamping device may be removed after the two piece “T” shaped box finger joint with dowel peg and finishing nails 900 is completed but prior to the glue cure time. The order in which the interlocking fingers 903 and 904 , the hole for the dowel peg 906 are formed, as well as the order of the glue application and clamping may be varied.
[0032] Alternatively, the back side interlocking fingers 903 may only come partially through the front side 901 . In addition, the front side interlocking fingers 904 may not be cut all the way through to the front side 901 . This is what is known as a blind interlocking box finger joint since the back side interlocking fingers cannot be seen from the front face of the front side 901 .
[0033] Other alternative embodiments may combine a tongue and groove joint with the interlocking finger box joint. A channel or dado is first cut through the back face of the front side 901 where it intersects with the back side 902 . Subsequently the front side interlocking fingers 904 may then be formed in the front side 901 . The back side interlocking fingers 903 may then be formed. The depth of the back side interlocking fingers 903 may be cut equal to the thickness of the front side 901 minus the depth of the channel or dado cut into the back face of the front side 901 . The front side 901 and the back side 902 may then be combined with the back side 902 partially embedded into the dado or channel in the front side 901 .
[0034] FIG. 10 illustrates an alternative embodiment 1000 of the present invention showing a stronger three piece “T” shaped box finger joint with dowel peg and finishing nails. The left side 1001 of the box finger joint 1000 is created by cutting or forming the alternating left side interlocking fingers 1004 . The right side 1008 of the box finger joint 1000 is created by cutting or forming the alternating right side interlocking fingers 1007 . In a similar manner, the back side 1002 of the box finger joint 1000 is created by cutting or forming the alternating back side interlocking fingers 1003 . Subsequently the left side 1001 , right side 1008 and back side 1002 are joined together and the interface between the back side interlocking fingers 1003 , left side interlocking fingers 1004 and right side interlocking fingers 1007 , are typically clamped in a clamping device. While still in the clamping device, a round hole is drilled at the top corner of 1000 . The pieces can now be removed from the clamping device. Glue is placed in the drilled hole and at the interface of the left, right and back side interlocking fingers 1004 , 1007 , and 1003 respectively. The pieces are clamped in a clamping device and subsequently a dowel peg 1006 is placed in the hole. After insertion of the dowel peg 1006 , finishing nails 1005 are driven into the left and right side interlocking fingers 1004 and 1007 and through the dowel peg 1006 and into the back side 1002 . The clamping device may be left in place until the glue has cured. Alternatively the clamping device may be removed after the three piece “T” shaped box finger joint with dowel peg and finishing nails 1000 is completed but prior to the glue cure time. The order in which the interlocking fingers 1003 , 1004 and 1007 , the hole for the dowel peg 1006 are formed, as well as the order of the glue application and clamping may be varied.
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A method of constructing an interlocking corner joint by combining fixed or variable sized interlocking fingers from at least two sides, full or partial feed though dowel pegs or other geometrically shaped pegs, finishing nails, pins or screws and glue or epoxy at the interface of the interlocking fingers and pegs and pins. The resulting interlocking corner joint is much stronger than a standard dovetail joint or box finger joint due to the increased surface area created by the holes, pegs and pins. Due to the interlocking fingers, holes, pegs and pins, the interlocking corner joint will not pull apart in any one dimension x,y,z in the event that the glue joint fails.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional Patent Application No. 62/235,763, filed on Oct. 1, 2015, which is incorporated herein by reference in its entirety.
TECHNICAL FIELD
[0002] The present disclosure relates generally to an apparatus for mixing liquids in a container using a pulsed gas, such as air.
SUMMARY
[0003] A pulsed gas mixing system utilizes large bubbles of gas (typically air) rising from the bottom of a container to induce a mixing flow within a separated solution. A large flat single bubble provides the greatest efficiency and is typically induced by introducing a sudden pulse of gas below a flat round steel plate suspended a fixed distance from the floor of the container. Ideally, this will produce a toroid (donut shaped) bubble having an even cross-section around the entire circumference of the bubble. The forces resulting from the surface tension on the bubble will rapidly pull the bubble together into the desired saucer (large flat) shape.
[0004] With respect to mixing efficiency using a pulsed gas system, the greatest efficiency is achieved by limiting the number of bubbles, and maximizing the size of the bubbles. In other words, the mixing is less efficient as the number of small bubbles increases. In addition, the efficiency increases as the number of large-sized bubbles decreases. Therefore, the most efficient solution is using one large, flat bubble.
[0005] The above-described method of creating the single flat bubble is generally reliable when the round steel plate can be precisely manufactured and accurately placed and leveled at the bottom of the container. Typically it is secured to the base of the container to maintain its precision. However, this methodology cannot be used when the container is semi-permanent, disposable, or recyclable. Also this methodology cannot be used when the mixing system is relocated from one container to the next. In these cases, the level, alignment, and spacing from the base are all subject to variation.
[0006] When the level, alignment, and spacing from the base of the container are irregular or varying, the bubble shape and size may not be reliably produced. Even if the toroid shape is produced, it is typically irregular and can break apart into multiple bubbles. More typically a series of smaller bubbles may be ejected from a single side of the plate. These multiple smaller bubbles still produce a mixing flow, however with reduced efficiency.
[0007] FIG. 1 depicts an example of a device used in the related art for producing a gas bubble in a mixing system. As shown in FIG. 1 , the device includes a rigid steel plate 100 at the end of a rigid steel tube 105 extending down from the top of the container 110 , and scaled to fit a correct distance to the bottom of the container 110 . However, this method is often too expensive in relation to the cost of the container and may not repeatedly provide the correct spacing from the bottom. Additionally small movements such as flexing in the top of the container 110 can cause large variations in the positioning of the plate 100 at the bottom of the container 110 . These variations in the plate positioning create mixing inefficiency due to an increased number of bubbles, smaller bubbles, etc.
[0008] Alternatively, the rigid steel tube can be replaced with a compressible plastic tube 205 , as shown in FIG. 2 . In addition, feet or stand-offs (not shown) can be added to the steel mixing plate 200 . In this configuration the plate 200 is pressed down to a fixed distance from the base of the container 210 . This resolves the location and spacing issues of the above configuration, however the plate 200 will only be as level as the base of the container 210 . Furthermore, the buoyancy effect of the gas spreading unevenly across the face of the plate 200 may produce an uneven lifting force which will increase the unevenness. Accordingly, an improved pulsed gas mixing apparatus is needed that reliably mixes the liquid in a variety of applications.
[0009] According to an aspect of one or more exemplary embodiments there is provided a pulsed gas mixing apparatus that provides for more consistent generation of gas bubbles that efficiently mix the contents of the container. The pulsed gas mixing apparatus may include a mixing plate having a top side and bottom side. The top side may be substantially smooth, and the bottom side may have a plurality of ribs.
[0010] The ribs of the mixing plate may radiate outwardly from the center of the mixing plate to an outer edge of the mixing plate. The mixing plate may include one or more feet coupled to one or more of the outer edge of the mixing plate and one or more of the plurality of ribs. At least one of the plurality of ribs may be substantially triangular-shaped having a first height near the center the mixing plate that is greater than a second height near the outer edge of the mixing plate. The mixing plate may be substantially circular. The mixing plate may also, or alternatively, be conically-shaped.
[0011] The one or more feet of the pulsed gas mixing apparatus may be disposed along the outer edge of the mixing plate. The one or more feet may be disposed where a rib of the first plurality of ribs intersects with the outer edge of the mixing plate. Alternatively, one or more feet may be disposed on one or more ribs of the plurality of ribs. The ribs may be substantially equidistantly-spaced from each other. In addition, at least one of the ribs of the plurality of ribs may be a spiral rib.
[0012] According to one or more exemplary embodiments, the pulsed gas mixing apparatus may also include a supply tube configured to be coupled to the mixing plate, and to supply a mixing gas. The supply tube may include one or more pluralities of ribs that extend circumferentially around the supply tube. The supply tube may include two sets of ribs that are axially-spaced from each other. The number of ribs on the supply tube may equal the number of ribs in the mixing plate.
BRIEF DESCRIPTION OF DRAWINGS
[0013] FIG. 1 illustrates a pulsed gas mixing plate apparatus according to the related art.
[0014] FIG. 2 illustrates another pulsed gas mixing plate apparatus according to the related art.
[0015] FIG. 3 illustrates a pulsed gas mixing apparatus according to an exemplary embodiment.
[0016] FIG. 4 illustrates a pulsed gas mixing apparatus according to another exemplary embodiment.
[0017] FIG. 5 illustrates a pulsed gas mixing apparatus according to another exemplary embodiment.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0018] Reference will now be made in detail to the following exemplary embodiments, which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. The exemplary embodiments may be embodied in various forms without being limited to the exemplary embodiments set forth herein. Descriptions of well-known parts are omitted for clarity.
[0019] FIG. 3 depicts a pulsed gas mixing apparatus according to an exemplary embodiment. Referring to FIG. 3 , the apparatus according to the exemplary embodiment may include a substantially circular plate 300 that may be made of plastic, steel, or other rigid materials. For example, the plate 300 may be made of molded plastic. The plate 300 may include one or more ribs 301 disposed on the bottom side of the plate. In the exemplary embodiment of FIG. 3 , the plate 300 includes eight ribs 301 extending in a radial direction from the center of the plate 300 , however the plate 300 may have any number of ribs 301 .
[0020] The ribs 301 on the bottom side of the plate 300 may function to divide the gas flow into approximately even divisions, which may reduce the risk that the bubble will have an irregular cross section and/or that multiple small bubbles will be created. In addition, the tube 305 which supplies the mixing gas may also include ribs 306 to further ensure the equal division of gas flow. The tube 305 may have the same number of ribs 306 as the plate 300 , or may have a different number of ribs than the plate 300 . In addition, the tube 305 may have ribs 306 that extend different distances along an axial length of the tube 305 . For example, in the exemplary embodiment of FIG. 3 , the tube 305 may include four ribs 306 that continue up the supply tube 307 for several inches, and four ribs 306 that continue up the supply tube 305 by a shorter distance. The tube 305 may be made of plastic or steel, and is preferably a compressible plastic tube.
[0021] FIG. 4 depicts a mixing apparatus according to another exemplary embodiment. Referring to FIG. 4 , the plate 400 may be conically-shaped to further ensure air flow balancing. The conical shape allows for a slight build of air pressure to resist air flow in sections of the plate 400 that are already receiving additional air flow. The conical shape also ensures that small bubbles do not prematurely roll off the edge of the plate 400 . The mixing apparatus of this exemplary embodiment may include four ribs 401 that reinforce the conically-shaped plate 400 , although a different number of ribs may be used. The apparatus may also include one or more feet 402 extending downward from the outer circumference of the plate 400 . The one or more feet 402 may elevate the plate 400 an appropriate distance from the floor of the container. The one or more feet 402 may be pressed against the floor of the container by the compressive force of the gas tube 405 . Although the exemplary embodiment of FIG. 4 is depicted with four ribs, the plate 400 may have greater or fewer ribs. In addition, the plate 400 may have any number of feet 402 , and is not limited to the specific exemplary embodiment shown in FIG. 4 . Moreover, the one or more feet 402 may be located anywhere along the circumference of the plate 400 , or may be located on the bottom side of one or more ribs 401 within the circumference of the plate 400 .
[0022] By dividing the gas flow, the ribs 401 balance the pressure and flow of the gas across the surface of the plate 400 . The resulting consistent buoyancy force maintains the plate 400 in a level position that is roughly parallel with the bottom of the container. Balancing the gas flow and maintaining the plate 400 in a level position produces a more consistent and efficient bubble.
[0023] Although the ribs of the exemplary embodiment of FIGS. 3 and 4 extend radially from the center of the plate, the apparatus may include spiral ribs, or ribs that in some manner index 180 degrees from the center of the plate to the edge of the plate. This configuration would distribute minute variations in pressure from the high pressure side of the plate to the low pressure side, further leveling the plate.
[0024] FIG. 5 shows pulsed gas mixing apparatus according to another exemplary embodiment. Referring to FIG. 5 , the pulsed gas mixing apparatus according to the exemplary embodiment is similar to the exemplary embodiments of FIGS. 3 and 4 . For example, the apparatus according to the exemplary embodiment includes a top plate 500 and ribs 501 , but also includes a bottom plate 502 disposed below ribs 501 . The tube 505 supplies the mixing gas through the top plate 500 and engages the ribs 501 and bottom plate 502 . The bottom plate 502 directs the flow of the mixing gas laterally toward the edges of the top plate 500 , and limits the amount of mixing gas that exits the top plate 500 from below. The ribs 501 divides the mixing gas into approximately even divisions as the mixing gas is channeled toward the edges of the top plate 500 .
[0025] Although the inventive concepts of the present disclosure have been described and illustrated with respect to exemplary embodiments thereof, it is not limited to the exemplary embodiments disclosed herein and modifications may be made therein without departing from the scope of the inventive concepts.
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A pulsed gas mixing apparatus is provided. The pulsed gas mixing apparatus may include a mixing plate having a top side that is substantially smooth, and a bottom side that includes a plurality of ribs. The pulsed gas mixing apparatus may also include a supply tube configured to be coupled to the mixing plate and supply a mixing gas that is used to mix the contents a container in which the pulsed gas mixing apparatus is installed.
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CROSS-REFERENCE TO PRIORITY APPLICATIONS
This application is a continuation of commonly assigned U.S. patent application Ser. No. 12/614,011 for a Reduced-Diameter Optical Fiber (filed Nov. 6, 2009, and published May 13, 2010, as U.S. Patent Application Publication No. 2010/0119202 A1), now U.S. Pat. No. 8,600,206. Parent U.S. patent application Ser. No. 12/614,011 further claims the benefit of U.S. Provisional Application No. 61/112,595 for a Microbend-Resistant Optical Fiber (filed Nov. 7, 2008), U.S. Provisional Application No. 61/177,996 for a Reduced-Diameter Optical Fiber (filed May 13, 2009), and U.S. Provisional Application No. 61/248,319 for a Reduced-Diameter Optical Fiber (filed Oct. 2, 2009). Each foregoing commonly assigned patent application, patent application publication, and patent is hereby incorporated by reference in its entirety.
FIELD OF THE INVENTION
The present invention embraces optical fibers possessing an improved coating system that reduces stress-induced microbending. The present invention further embraces the deployment of such optical fibers in various structures, such as buffer tubes and cables.
BACKGROUND OF THE INVENTION
Fiber to the premises/business/home (i.e., FTTx) provides broadband data transfer technology to the individual end-user. FTTx installations, which are being increasingly deployed throughout the world, are making use of innovative, reduced-cost system designs to promote the spread of the technology. For example, fiber may be delivered in the last link by way of a microcable. Air-blown fibers provide another efficient model for delivering the link to the end-use terminus. There continues to be industry-wide focus on modes of deployment that overcome economic obstacles that impede fiber-based broadband solutions for data transmission to businesses and residences.
Cost-effectiveness is important, of course, for achieving successful FTTx systems. Reduced size for cables, drops, and structures for blowing are often critical, too. Installation of conduits suitable for traditional cable designs is often prohibitive in existing infrastructure. Thus, existing small ducts or tight pathways have to be used for new fiber installations. Low-cost and reduced-size requirements are driving in a direction that reduces protection for the optical fibers (i.e., away from conventionally robust, more bulky cable designs).
Glass designs are now available that offer reduced sensitivity to small bending radius (i.e., decreased added attenuation due to the phenomenon known as macrobending). These include trench-assisted core design or void-assisted fibers. Glass designs with lower mode field diameter are less sensitive to macrobending effects, but are not compatible with the G.652 SMF standard. Single-mode optical fibers that are compliant with the ITU-T G.652.D requirements are commercially available, for instance, from Draka Comteq (Claremont, N.C.).
Microbending is another phenomenon that induces added loss in fiber signal strength. Microbending is induced when small stresses are applied along the length of an optical fiber, perturbing the optical path through microscopically small deflections in the core.
In this regard, U.S. Pat. No. 7,272,289 (Bickham et al.), which is hereby incorporated by reference in its entirety, proposes an optical fiber having low macrobend and microbend losses. U.S. Pat. No. 7,272,289 broadly discloses an optical fiber possessing (i) a primary coating having a Young's modulus of less than 1.0 MPa and a glass transition temperature of less than −25° C. and (ii) a secondary coating having a Young's modulus of greater than 1,200 MPa.
Nonetheless, better protection against microbending is still needed to help ensure successful deployment in more FTTx applications. To this end, it is necessary to discover and implement new coating systems that better address the demands FTTx installations place on fiber and cable structures in a way that is commercially practical (i.e., cost-effective).
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide an optical fiber having an improved coating system that provides improved protection against stress-induced microbending.
It is another object to provide an improved coating system that can be readily mated with either single-mode optical fiber or multimode optical fiber.
It is yet another object to provide an improved coating system that can be readily mated with bend-insensitive optical fiber.
It is yet another object to provide an improved optical fiber coating system including a primary coating that possesses a low modulus to provide enhanced cushioning against lateral and axial stresses induced by external forces.
It is yet another object to provide an improved optical fiber coating system including a primary coating that possesses an exceptionally low glass transition temperature (T g ) that reduces temperature-induced stresses in unusually cold environments.
It is yet another object to provide an improved optical fiber coating system including a primary coating that possesses an improved curing rate.
It is yet another object to provide an improved optical fiber coating system including an ink-free secondary coating that has improved brightness and visibility.
It is yet another object to provide an improved optical fiber coating system that can be applied at commercial processing speeds (e.g., forming the primary coating at rates of at least about 20 meters per second).
It is yet another object to provide an optical fiber possessing coatings that are readily stripped.
It is yet another object to provide an optical fiber having enhanced performance characteristics for use in FTTx installations in which conventional, robust cable designs are impractical.
It is yet another object to provide an optical fiber that synergistically combines a bend-insensitive glass fiber (e.g., Draka Comteq's single-mode glass fibers available under the trade name BendBright XS ®) with the coating according to the present invention (e.g., Draka Comteq's ColorLock XS brand coating system).
It is yet another object to provide an optical fiber that can be advantageously deployed in buffer tubes and/or fiber optic cables.
It is yet another object to provide an optical fiber that requires less external protection (e.g., enclosed within thinner buffer tubes and/or cable jacketing).
It is yet another object to provide a bend-insensitive optical fiber possessing a reduced diameter (e.g., having thinner coating layers and/or a thinner component glass fiber).
It is yet another object to provide a reduced-diameter optical fiber that requires less deployment space (e.g., within a buffer tube and/or fiber optic cable), thereby facilitating increased fiber count and/or reduced cable size.
It is yet another object to provide an optical fiber that can be installed in a way that employs small-radius bends.
It is yet another object to provide an optical fiber that facilitates direct installation onto buildings or other structures (e.g., stapled or otherwise secured to structural surfaces).
It is yet another object to provide a 200-micron single-mode optical fiber that provides significantly better microbending performance than that of a standard single-mode optical fiber (SSMF) that employs conventional primary and secondary coatings (i.e., at an outer diameter of about 235-265 microns).
The foregoing, as well as other objectives and advantages of the invention, and the manner in which the same are accomplished, are further specified within the following detailed description and its accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts microbend testing results demonstrating that exceptionally low microbending losses are achieved, in accordance with the present invention, by pairing a bend-insensitive glass fiber with a low-modulus primary coating.
FIG. 2 schematically depicts the relationship between the in situ modulus of a primary coating and added loss for a multimode optical fiber.
FIG. 3 depicts the dynamic mechanical properties of a typical commercial primary coating (i.e., a conventional primary coating).
FIG. 4 depicts the dynamic mechanical properties of an exemplary primary coating used in producing optical fibers according to the present invention.
FIG. 5 depicts microbend testing results for optical fibers that include a conventional primary coating and for optical fibers that include an exemplary primary coating according to the present invention.
FIG. 6 depicts microbend testing results (under rigorous temperature-cycle testing conditions) for optical fibers that include a conventional primary coating and for optical fibers that include an exemplary primary coating according to the present invention.
FIG. 7 depicts microbend testing results (under modified temperature-cycle testing conditions) for optical fibers that include a conventional primary coating and for optical fibers that include an exemplary primary coating according to the present invention.
FIG. 8 depicts microbend testing results demonstrating that exceptionally low microbending losses are achieved, in accordance with the present invention, by pairing a bend-insensitive glass fiber with a low-modulus primary coating.
FIG. 9 depicts microbend testing results (under rigorous temperature-cycle testing conditions) for conventional optical fibers and for optical fibers that, in accordance with the present invention, combine a bend-insensitive glass fiber with a low-modulus primary coating.
FIG. 10 depicts microbend testing results (under modified temperature-cycle testing conditions) for conventional optical fibers and for optical fibers that, in accordance with the present invention, combine a bend-insensitive glass fiber with a low-modulus primary coating.
FIG. 11 depicts attenuation (added loss) as a function of MAC number (i.e., mode field diameter divided by cutoff wavelength) for various exemplary optical fibers.
FIG. 12 depicts, on a logarithmic scale, microbend sensitivity as a function of MAC number (i.e., mode field diameter divided by cutoff wavelength) for various exemplary optical fibers.
DETAILED DESCRIPTION
In one aspect, the present invention embraces optical fibers possessing an improved coating system that reduces stress-induced microbending, even in exceptionally cold environments required for FTTx deployments. The coating system according to the present invention includes a primary coating that combines low in situ modulus (e.g., less than about 0.5 MPa as measured on the fiber) and low glass transition temperature (T g ) (e.g., less than about −50° C.) to reduce stresses caused by external force and temperature. In addition, the coating system can be processed at high production speeds (e.g., 15-20 msec or more).
The present invention achieves a microbend-resistant optical fiber, particularly a single-mode optical fiber, by employing as its primary coating a UV-curable, urethane acrylate composition. In this regard, the primary coating includes between about 40 and 80 weight percent of polyether-urethane acrylate oligomer as well as photoinitiator, such as LUCERIN TPO, which is commercially available from BASF. In addition, the primary coating includes one or more oligomers and one or more monomer diluents (e.g., isobornyl acrylate), which may be included, for instance, to reduce viscosity and thereby promote processing. A suitable composition for the primary coating according to the present invention is a UV-curable urethane acrylate product provided by DSM Desotech (Elgin, Ill.) under the trade name DeSolite® DP 1011.
In this regard, this application incorporates entirely by reference the following commonly assigned patent application publications and patent applications: U.S. Patent Application No. 60/986,737 for a Microbend-Resistant Optical Fiber, filed Nov. 9, 2007, (Overton); U.S. Patent Application No. 61/041,484 for a Microbend-Resistant Optical Fiber, filed Apr. 1, 2008, (Overton); U.S. Patent Application No. 61/112,595 for a Microbend-Resistant Optical Fiber, filed Nov. 7, 2008, (Overton); International Patent Application Publication No. WO 2009/062131 A1 for a Microbend-Resistant Optical Fiber, (Overton); and U.S. Patent Application Publication No. US2009/0175583 A1 and its counterpart U.S. patent application Ser. No. 12/267,732 for a Microbend-Resistant Optical Fiber, (Overton).
This application further incorporates entirely by reference the following commonly assigned patents, patent application publications, and patent applications: U.S. Pat. No. 4,838,643 for a Single Mode Bend Insensitive Fiber for Use in Fiber Optic Guidance Applications (Hodges et al.); U.S. Patent Application Publication No. US2007/0127878 A1 for a Single Mode Optical Fiber (de Montmorillon et al.); U.S. Pat. No. 7,587,111 for a Single-Mode Optical Fiber (de Montmorillon et al.); U.S. Pat. No. 7,356,234 for a Chromatic Dispersion Compensating Fiber (de Montmorillon et al.); U.S. Pat. No. 7,483,613 for a Chromatic Dispersion Compensating Fiber (de Montmorillon et al.); U.S. Pat. No. 7,555,186 for an Optical Fiber (Flammer et al.); U.S. patent application Ser. No. 12/098,804 for a Transmission Optical Fiber Having Large Effective Area (Sillard et al.), filed Apr. 7, 2008; U.S. Patent Application Publication No. US2009/0252469 A1 for a Dispersion-Shifted Optical Fiber (Sillard et al.); U.S. patent application Ser. No. 12/436,423 for a Single-Mode Optical Fiber Having Reduced Bending Losses, filed May 6, 2009, (de Montmorillon et al.); U.S. patent application Ser. No. 12/436,484 for a Bend-Insensitive Single-Mode Optical Fiber, filed May 6, 2009, (de Montmorillon et al.); U.S. patent application Ser. No. 12/489,995 for a Wavelength Multiplexed Optical System with Multimode Optical Fibers, filed Jun. 23, 2009, (Lumineau et al.); U.S. patent application Ser. No. 12/498,439 for a Multimode Optical Fibers, filed Jul. 7, 2009, (Gholami et al.); U.S. Patent Application No. 61/101,337 for a Bend-Insensitive Optical Fiber, filed Sep. 30, 2008, (de Montmorillon et al.); U.S. Patent Application No. 61/112,006 for a Bend-Insensitive Single-Mode Optical Fiber, filed Nov. 6, 2008, (de Montmorillon et al.); U.S. Patent Application No. 61/112,374 for a Bend-Insensitive Single-Mode Optical Fiber, filed Nov. 7, 2008, (de Montmorillon et al.).
One exemplary glass fiber, for instance, possesses a step-index core having a refractive index that is between about 0.003 and 0.006 higher than the refractive index of its adjacent silica cladding.
Exemplary single-mode glass fibers for use in the present invention are commercially available from Draka Comteq (Claremont, N.C.) under the trade name BendBright®, which is compliant with the ITU-T G.652.D requirements, and the trade name BendBright XS ®, which is compliant with the ITU-T G.657.A/B and ITU-T G.652.D requirements.
In particular and as set forth herein, it has been unexpectedly discovered that the pairing of a bend-insensitive glass fiber (e.g., Draka Comteq's single-mode glass fibers available under the trade name BendBright XS ®) and a primary coating having very low modulus (e.g., DSM Desotech's UV-curable urethane acrylate product provided under the trade name DeSolite® DP 1011) achieves optical fibers having exceptionally low losses (e.g., reductions in microbend sensitivity of at least 10× (e.g., 40× to 100× or more) as compared with a single-mode fiber employing a conventional coating system). Draka Comteq's bend-resistant, single-mode glass fiber available under the trade name BendBright XS ® employs a trench-assisted design that reduces microbending losses.
FIG. 1 depicts this outstanding result by comparing the aforementioned exemplary single-mode fiber according to the present invention with various single-mode fibers employing conventional coating systems. In this regard, FIG. 1 presents spectral attenuation data by measuring initial spectral attenuation on the optical fiber on a shipping spool, thereby obtaining the peaks and valleys typical of the attenuation across the full spectrum of wavelengths between the limits shown. The optical fiber is then wound onto a sandpaper-covered, fixed-diameter drum (i.e., measurement spool) as described by the IEC fixed-diameter sandpaper drum test (i.e., IEC TR62221, Method B), and another spectral attenuation curve is obtained.
The IEC fixed-diameter sandpaper drum test (i.e., IEC TR62221, Method B) provides a microbending stress situation that affects single-mode fibers even at room temperature. The sandpaper, of course, provides a rough surface that subjects the optical fiber to thousands, if not millions, of stress points. With respect to the test data presented in FIG. 1 , a 300-mm diameter fiber spool was wrapped with adhesive-backed, 40-micron grade sandpaper (i.e., approximately equivalent to 300-grit sandpaper) to create a rough surface. Then, 400-meter fiber samples were wound at about 2,940 mN (i.e., a tension of 300 gf on a 300-mm diameter cylinder), and spectral attenuation was measured at 23° C.
The curves presented in FIG. 1 represent the difference between the initial spectral curve and the curve when the fiber is on the sandpaper drum, thereby providing the added loss due to microbending stresses.
Those having ordinary skill in the art will recognize cable designs are now employing smaller diameter buffer tubes and less expensive materials in an effort to reduce costs. Consequently, when deployed in such cable designs, single-mode optical fibers are less protected and thus more susceptible to stress-induced microbending. As noted, the present invention provides an improved coating system that better protects optical fibers against stresses caused by external mechanical deformations and by temperature-induced, mechanical property changes to the coatings.
As noted, conventional solutions for protecting optical fibers involved using large-diameter buffer tubes, buffer tubes made of high-modulus materials that resist deformation and stresses upon the fiber, and stronger, thicker cable jackets to resist deformations that might pinch or otherwise squeeze the optical fibers. These solutions, however, are not only costly, but also fail to address the temperature-induced stresses caused by changes to the protective coatings. In other words, conventional primary coatings possess high modulus at temperatures below their respective glass transition temperatures.
As disclosed herein, the optical fiber according to the present invention includes a primary coating possessing lower modulus and lower glass transition temperature than possessed by conventional single-mode fiber primary coatings. Even so, the improved primary coating formulation nonetheless facilitates commercial production of the present optical fiber at excellent processing speeds (e.g., 1,000 m/min or more). In this regard, the primary coating employed in the optical fibers of the present invention possesses fast curing rates—reaching 50 percent of full cure at a UV dose of about 0.3 J/cm 2 , 80 percent of full cure at a UV dose of about 0.5 J/cm 2 , and 90 percent of full cure at a UV dose of about 1.0 J/cm 2 as measured on a standard 75-micron film at 20° C. and atmospheric pressure (i.e., 760 ton) (i.e., standard temperature and pressure—STP).
FIG. 2 schematically depicts the observed relationship between the in situ modulus of a primary coating and the attenuation (added loss) of the optical fiber, here a 50-micron graded-index multimode fiber. The primary coating modulus is measured as cured on the glass fiber and the added loss is measured using a fixed-diameter sandpaper drum procedure in accordance with the IEC TR62221 microbending-sensitivity technical report and standard test procedures e.g., IEC TR62221, Method B, Ed. 1), which are hereby incorporated by reference in their entirety.
As will be appreciated by those having ordinary skill in the art, prior, commercially available single-mode fibers typically include a Young's modulus of 100-150 psi measured in situ (i.e., on the fiber). The optical fiber according to the present invention possesses a primary coating having reduced modulus as compared with such commercially available primary coatings. Employing a lower modulus primary coating provides better cushioning around the glass fiber.
Although lower modulus of the in situ primary coating can be achieved by selectively undercuring, the present invention achieves in situ primary coating having lower modulus even approaching full cure (i.e., near full cure). In this regard, the modulus of the in situ primary coating according to the present invention is less than about 0.65 MPa (e.g., less than about 95 psi), typically less than about 0.5 MPa, and more typically less than 0.4 MPa (e.g., between about 0.3 MPa and 0.4 MPa or between about 40 psi and 60 psi). It has been determined that an in situ primary coating having a modulus of less than about 0.5 MPa significantly reduces bend sensitivity of the glass fiber. On the other hand, the modulus of the in situ primary coating according to the present invention is typically greater than about 0.2 MPa (e.g., 0.25 MPa or more).
To achieve its reduced modulus as compared with conventional optical fiber coatings, the present primary coating possesses a lower crosslink density, specifically a reduced concentration of the reactive acrylate groups. Those having ordinary skill in the art will appreciate that acrylate groups crosslink via free radical polymerization during photoinitiation (e.g., UV-induced curing during drawing operations). The reaction kinetics dictate reduced cure rates during processing. This is commercially undesirable, of course, and so the present invention implements processing modifications to provide satisfactory cure rate for the low-modulus primary coating.
There are at least two components of the curing process that retard the rate of polymerization of the primary coating. First, the combination of (i) high curing temperatures induced by exposure to a high-intensity, UV environment and (ii) the exothermic polymerization reaction slows the observed curing rate of the primary coating. Second, close proximity of stacked UV lamps, in effect, creates rapidly superposed, repeated photoinitiation periods. The reaction rate of acrylate groups under this configuration is likewise retarded—a somewhat counterintuitive result. With respect to the latter, disposing (i.e., positioning) UV lamps to increase the period between consecutive UV exposures significantly increases the degree of coating cure as compared with other conventional processes employing the same draw speed and UV dose. In this way, it is possible to process the reduced-modulus, primary coating according to the present invention in a way that achieves near-complete curing at fast fiber draw speeds, which are required for a commercially viable process. An exemplary method and apparatus for curing a coated fiber is disclosed in commonly assigned U.S. Pat. No. 7,322,122, which is hereby incorporated by reference in its entirety.
The temperature dependence of the modulus is an important consideration to ensure that the primary coating provides enhanced microbending protection in FTTx applications. A primary coating having low modulus only at room temperature would be inadequate because deployment in the field will expose the optical fiber to microbend-inducing stresses at extreme environmental temperatures (e.g., −40° C. and below). Therefore, a suitable primary coating according to the present invention possesses an exceptionally low glass transition temperature so that the primary coating remains soft and protective in extremely cold environmental conditions.
Example 1
Comparison of Mechanical Properties
FIGS. 3 and 4 , respectively, depict dynamic mechanical properties of a typical commercial primary coating (i.e., the conventional primary coating) and an exemplary primary coating used in making the optical fibers according to the present invention. The conventional primary coating was a UV-curable urethane acrylate provided by DSM Desotech (Elgin, Ill.) under the trade name DeSolite® DP 1007. The exemplary primary coating according to the present invention (i.e., employed to form optical fibers of the present invention) was a UV-curable urethane acrylate provided by DSM Desotech (Elgin, Ill.) under the trade name DeSolite® DP 1011.
The data for the conventional primary coating were obtained on a Dynamic Mechanical Analyzer (DMA) at an oscillatory stress rate of 1 Hz. In doing so, the strain was maintained within the linear region of stress-strain behavior. The sample of conventional primary coating was cured on polyester to form a standard 75-micron film. A UV dose of 1 J/cm 2 was applied using a mercury-halide bulb operating at a 300 W/in output. This UV exposure was sufficient to ensure that the coating was on the plateau of the dose-modulus curve.
Referring to FIG. 3 , the data show the equilibrium modulus to be approximately 1.5 MPa as measured on a 75-micron film. On a glass fiber (i.e., in situ), this conventional primary coating typically cures well to a modulus of about 0.8 MPa, a level indicative of many single-mode fiber primary coatings in the industry. Those having ordinary skill in the art will appreciate that modulus measurements of softer primary coatings tend to be lower on a glass fiber (i.e., in situ) as compared with on a 75-micron film.
The glass transition temperature of the conventional primary coating is estimated by the peak in tan δ to be approximately −30° C. Thus, the conventional primary coating (and similar formulations) will behave like a glassy polymer at extremely low temperatures (e.g., less than −40° C., particularly less than −50° C.). (Although stress induced by strain is time dependent at low temperatures, estimated glass transition temperature is a useful comparative property.)
A sample of the exemplary primary coating according to the present invention was likewise cured on polyester to form a comparable 75-micron film. As before, a UV dose of 1 J/cm 2 was applied to the primary coating using a mercury-halide bulb operating at a 300 W/in output. As noted, FIG. 4 depicts dynamic mechanical properties of the exemplary primary coating according to the present invention.
The exemplary primary coating according to the present invention exhibited an equilibrium modulus at just under 1 MPa in the cured film. The in situ modulus (i.e., measured on the glass fiber), was between about 0.3 MPa and 0.4 MPa. This is significantly lower than the respective modulus measurements for the conventional primary coating.
The glass transition temperature of the exemplary primary coating according to the present invention is estimated by the peak in tan δ at less than about −50° C. (e.g., about −60° C.). This is at least about 20° C. below the glass transition temperature of the comparative, conventional primary coating. Accordingly, primary coatings according to the present invention provide much more rapid stress relaxation during temperature excursions.
As set forth in Examples 2 and 3 (below), two different methods were used to evaluate the respective microbend sensitivities of glass fibers coated with (i) a typical commercial primary coating (i.e., the conventional primary coating) and (ii) an exemplary primary coating according to the present invention. As with Example 1 (above), the conventional primary coating was a UV-curable urethane acrylate provided by DSM Desotech (Elgin, Ill.) under the trade name DeSolite® DP 1007, and the exemplary primary coating according to the present invention (i.e., employed to form optical fibers of the present invention) was a UV-curable urethane acrylate provided by DSM Desotech (Elgin, Ill.) under the trade name DeSolite® DP 1011.
Each test method provided aggravated lateral stress conditions. Moreover, after measuring the effect on attenuation at room temperature, the test structures were temperature cycled to determine the additional loss induced by such temperature excursions.
Example 2
Comparison of Microbending Sensitivity
The first test method employed was a basket-weave, temperature cycling procedure known by those having ordinary skill in the art. According to this test procedure, optical fiber was wound at about 490 mN (i.e., a tension of 50 gf on a 300-mm diameter quartz cylinder with a 9-mm “lay”). Fifty layers were wound on the quartz drum to create numerous fiber-to-fiber crossovers. The testing procedure for Example 2 was an adaptation of IEC TR62221, Method D, which, as noted, is incorporated by reference in its entirety.
Those having ordinary skill in the art will appreciate that, at room temperature, such fiber crossovers can sometimes cause added loss (i.e., if the optical fiber is very sensitive) but that typically little or no added loss is observed. Consequently, the drum (with wound fiber) was temperature cycled twice from about room temperature through (i) −40° C., (ii) −60° C., (iii) +70° C., and (iv) +23° C. (i.e., near room temperature) while making loss measurements at 1550 nanometers. In both temperature cycles, fiber attenuation was measured after one hour at each test temperature.
FIG. 5 depicts exemplary results for single-mode glass fibers coated with, respectively, a conventional primary coating (i.e., DeSolite® DP 1007) and an exemplary primary coating according to the present invention (i.e., DeSolite® DP 1011). The respective fiber specimens were chosen to match the coating geometry, mode field diameter, and cutoff wavelength. Accordingly, the respective optical fibers employed different formulations of colored secondary coatings.
In summary, the conventional primary coating and the exemplary primary coating according to the present invention each provided good protection against microbending stresses at 23° C. Moreover, at −40° C., the optical fiber having the conventional primary coating demonstrated only a small added loss. (It would appear that at −40° C., the conventional primary coating provided adequate protection against microbending by stress relaxing in a reasonable timeframe, even though this was near its glass transition temperature.) By way of comparison, the optical fiber according to the present invention demonstrated essentially no added loss at −40° C. (i.e., better performance).
At −60° C., however, the optical fiber having the conventional primary coating demonstrated significant added loss. (This temperature extreme was well below the glass transition temperature of the conventional primary coating.) By way of comparison, the optical fiber according to the present invention demonstrated essentially no added loss at −60° C., which is close to the glass transition temperature of this embodiment of the primary coating according to the present invention.
Example 3
Comparison of Microbending Sensitivity
The second test method employed more aggressive environments (i.e., conditions) in order to evaluate the respective microbend sensitivities of (i) an optical fiber possessing a typical commercial primary coating (i.e., the conventional primary coating) and (ii) an optical fiber possessing an exemplary primary coating according to the present invention.
In particular, the second method modified the IEC fixed-diameter sandpaper drum test (i.e., IEC TR62221, Method B), which, as noted, is incorporated by reference in its entirety, to provide a microbending stress situation sufficiently harsh to affect single-mode fibers even at room temperature (i.e., a rougher drum surface than that used to measure the data depicted in FIG. 1 ). To do this, a 300-mm diameter quartz drum was wrapped with adhesive-backed, 220-grit sandpaper (i.e., approximately equivalent to 66-micron-grade sandpaper) to create a rough surface.
In an initial test condition, each of the respective fiber samples was wound in a single layer at about 980 mN (i.e., a tension of 100 gf on a 300-mm diameter quartz cylinder). In a modified test condition, three (3) each of the respective fiber samples was wound in a single layer at about 1,470 mN (i.e., a tension of 150 gf on a 300-mm diameter quartz cylinder). Thus, as compared with the first test condition, the second test condition increased the winding tension by 50 percent.
Using matched fiber samples (as with the basket weave/temperature cycling test of Example 2) fiber attenuation was measured after winding at room temperature (i.e., 23° C.) for each test condition. Then, the drum (with 400 meters of wound fiber) was temperature cycled from about room temperature through (i) −40° C., (ii) −60° C., and (iii) +23° C. (i.e., near room temperature) while making loss measurements at 1550 nanometers using an optical time domain reflectometer (OTDR).
The several samples of each kind of optical fiber were initially measured at 23° C. on the original spools (i.e., before winding on the roughened drum surface to establish baseline spectral attenuation) then were subjected to the foregoing rigorous testing conditions for one hour at each temperature. Fiber attenuation was measured after one hour (as in Example 2) at each test temperature.
FIG. 6 , a line chart, and FIG. 7 , a box plot, depict exemplary results under these more rigorous testing conditions for single-mode optical fibers that include a conventional primary coating (i.e., DeSolite® DP 1007 UV-curable urethane acrylate) and for single-mode optical fibers that include an exemplary primary coating according to the present invention (i.e., DeSolite® DP 1011 UV-curable urethane acrylate).
FIG. 6 , for instance, shows that, as compared with conventional optical fibers, exemplary optical fibers according to the present invention possess reduced microbend sensitivity (i.e., a reduction of about 40-60 percent).
Likewise, FIG. 7 shows that, as compared with conventional optical fibers, exemplary optical fibers according to the present invention possess substantially reduced microbend sensitivity at a higher winding tension (i.e., 150 gf on a 300-mm diameter quartz cylinder). FIG. 7 thus illustrates that the exemplary primary coating according to the present invention (i.e., DeSolite® DP 1011 UV-curable urethane acrylate) promotes both significantly reduced and significantly more uniform microbending performance.
In accordance with the foregoing, it has been found that, as compared with a conventional coating system, the present coating system provides significant microbending improvement when used in combination with a conventional single-mode glass fiber.
It has been further found that pairing a bend-insensitive glass fiber (e.g., Draka Comteq's single-mode glass fibers available under the trade name BendBright XS ®) and a primary coating having very low modulus (e.g., DSM Desotech's UV-curable urethane acrylate product provided under the trade name DeSolite® DP 1011) achieves optical fibers having exceptionally low losses. Additional testing was performed, therefore, to demonstrate the dramatic and unexpected reductions in microbend sensitivity provided in accordance with the present invention.
Example 4
Comparison of Microbending Sensitivity
The respective microbend sensitivities were measured for exemplary optical fibers, including (i) a conventional single-mode glass fiber with a conventional commercial coating, (ii) a bend-insensitive glass fiber with a conventional commercial coating, and (iii) a bend-insensitive glass fiber (e.g., Draka Comteq's single-mode glass fibers available under the trade name BendBright XS ®) with the coating according to the present invention (e.g., Draka Comteq's ColorLock XS brand coating system).
FIG. 8 demonstrates that the optical fiber according to the present invention, namely including a bend-insensitive glass fiber (e.g., Draka Comteq's single-mode glass fibers available under the trade name BendBright XS ®) and a primary coating having very low modulus (e.g., DSM Desotech's UV-curable urethane acrylate product provided under the trade name DeSolite® DP 1011), provides exceptionally low attenuation losses as compared with other optical fibers. Moreover, this bend-resistant optical fiber exhibits small wavelength dependence within the transmission window between 1400 nanometers and 1700 nanometers, and is essentially unaffected by the microbend-inducing test conditions across the test spectrum.
FIG. 8 presents exemplary spectral attenuation data obtained adhering to IEC TR62221, Method B (fixed-diameter drum). In accordance with IEC TR62221, Method B, initial spectral attenuation was measured on a 440-meter sample of optical fiber wound on a shipping spool (i.e., obtaining the peaks and valleys typical of the attenuation across the full spectrum of wavelengths between the limits shown). The optical fiber was then wound at about 3 N onto a 300-mm diameter measurement spool wrapped with adhesive-backed, 40-micron grade sandpaper (i.e., approximately equivalent to 300-grit sandpaper), and another spectral attenuation curve was obtained.
Like the curves presented in FIG. 1 , the curves depicted in FIG. 8 represent, at 23° C., the difference between the initial spectral curve and the curve when the fiber is on the sandpaper drum of fixed diameter, thereby providing the added loss due to microbending stresses (i.e., delta-attenuation across the spectral range).
Example 5
Comparison of Microbending Sensitivity
The respective microbend sensitivities were measured under rigorous test conditions for exemplary optical fibers, including (i) a conventional single-mode glass fiber with a conventional commercial coating and (ii) a bend-insensitive glass fiber (e.g., Draka Comteq's single-mode glass fibers available under the trade name BendBright XS ®) with the coating according to the present invention (e.g., Draka Comteq's ColorLock XS brand coating system).
FIG. 9 demonstrates that, even under extremely harsh conditions, the optical fiber according to the present invention, namely including a bend-insensitive glass fiber (e.g., Draka Comteq's single-mode glass fibers available under the trade name BendBright XS ®) and a primary coating having very low modulus (e.g., DSM Desotech's UV-curable urethane acrylate product provided under the trade name DeSolite® DP 1011), provides surprisingly low attenuation losses as compared with other optical fibers.
The testing procedure for Example 5 was an adaptation of IEC TR62221, Method B, which, as noted, is incorporated by reference in its entirety. For this modified IEC fixed-diameter sandpaper drum test, a 300-mm diameter quartz drum was wrapped with adhesive-backed, 180-grit sandpaper (i.e., approximately equivalent to 78-micron-grade sandpaper) to create an even rougher surface than that described in Example 3 (above). Then, 440-meter fiber samples were wound in a single layer at about 1,470 mN (i.e., a controlled back tension of 150 gf on the 300-mm diameter quartz cylinder using a Delachaux optical fiber winding apparatus), and spectral attenuation was measured.
FIG. 9 presents exemplary temperature-cycle data for three specimens of standard single-mode fiber (i.e., a conventional single-mode glass fiber with a conventional commercial coating) and three specimens of optical fiber according to the present invention (i.e., a bend-insensitive glass fiber with improved coating according to the present invention). As noted, 440 meters of optical fiber is wound onto the aforementioned sandpaper-covered, fixed-diameter drum. One hour after winding, fiber attenuation was measured at room temperature (i.e., 23° C.) using an optical time domain reflectometer (OTDR). Then, the drum (with 440 meters of wound fiber) was temperature cycled from about room temperature through (i) −40° C. and (ii) −60° C. in a temperature-controlled chamber. Fiber attenuation at 1550 nanometers was measured by an OTDR after one hour of equilibration at both −40° C. and −60° C.
Microbending sensitivity (S m ) may be described as αR/T, wherein α is the attenuation increase on the drum (dB/km), R is the radius of the fixed drum (mm), and T is the winding tension applied to the fiber (N). See e.g., IEC TR62221 Technical Report (Microbending Sensitivity). In addition to the parameters α, R, and T, however, the microbending-sensitivity metric obtained from the fixed-diameter sandpaper drum test is dependent on the coarseness of the sandpaper employed on the measurement drum.
Table 1 (below) presents the microbending-sensitivity metric obtained from the attenuation data (at a wavelength of 1550 nanometers) depicted in FIG. 9 (i.e., employing 180-grit sandpaper). Table 1 shows that, as compared with a conventional standard single-mode fiber, the optical fiber according to the present invention provides microbending sensitivity that is about 2×-10× lower at 23° C. and about 2×-5× lower at −40° C.:
TABLE 1
(Microbend Sensitivity)
−60° C.
Optical Fiber
23° C.
−40° C.
(dB/km)/
(Coating Color)
(dB/km)/(N/mm)
(dB/km)/(N/mm)
(N/mm)
Conventional SMF
139.9
220.6
331.8
(blue)
Conventional SMF
261.0
329.7
417.9
(red)
Conventional SMF
104.3
161.9
228.0
(aqua)
BendBright XS ® w/
35.8
76.5
163.4
ColorLock XS (slate)
BendBright XS ® w/
30.1
70.6
144.2
ColorLock XS (red)
BendBright XS ® w/
42.7
84.7
166.4
ColorLock XS (aqua)
Example 6
Comparison of Microbending Sensitivity
The respective microbend sensitivities were further measured for exemplary optical fibers, including (i) a conventional single-mode glass fiber with a conventional commercial coating and (ii) a bend-insensitive glass fiber (e.g., Draka Comteq's single-mode glass fibers available under the trade name BendBright XS ®) with the coating according to the present invention (e.g., Draka Comteq's ColorLock XS brand coating system).
The testing procedure for Example 6 was an adaptation of IEC TR62221, Method B, which, as noted, is incorporated by reference in its entirety. For this modified IEC fixed-diameter sandpaper drum test, a 300-mm diameter quartz drum was wrapped with adhesive-backed, 220-grit sandpaper (i.e., approximately equivalent to 66-micron-grade sandpaper) to create a rough surface like that described in Example 3. Each of the fiber samples was wound in a single layer at about 1,470 mN (i.e., a tension of 150 gf on a 300-mm diameter quartz cylinder). As compared with the test conditions of Example 5, the test conditions of Example 6 employed finer grade sandpaper (i.e., 220-grit rather than 180-grit).
As in Example 3, using matched fiber samples, fiber attenuation was measured after winding at room temperature (i.e., 23° C.). Then, the drum (with about 400 meters of wound fiber) was temperature cycled from about room temperature through (i) −40° C., (ii) −60° C., and (iii) +23° C. (i.e., near room temperature) while making loss measurements at 1550 nanometers using an optical time domain reflectometer (OTDR).
Three (3) samples of each kind of optical fiber were initially measured at 23° C. on the original spools (i.e., before winding on the roughened drum surface to establish baseline spectral attenuation) and then were subjected to the foregoing rigorous testing conditions for one hour at each temperature. Fiber attenuation was measured after one hour at each temperature.
FIG. 10 depicts exemplary results for single-mode optical fibers that include a conventional primary coating (i.e., DeSolite® DP 1007 UV-curable urethane acrylate) and for bend-insensitive glass fibers (e.g., Draka Comteq's single-mode glass fibers available under the trade name BendBright XS ®) that include a primary coating having very low modulus (i.e., DSM Desotech's UV-curable urethane acrylate product provided under the trade name DeSolite® DP 1011).
FIG. 10 demonstrates that the optical fiber according to the present invention, namely Draka Comteq's single-mode glass fibers available under the trade name BendBright XS ® with a primary coating having very low modulus (e.g., DSM Desotech's UV-curable urethane acrylate product provided under the trade name DeSolite® DP 1011), provides exceptionally low attenuation losses as compared with standard single-mode optical fibers (SSMF).
In addition, FIGS. 11 and 12 depict attenuation and microbend sensitivity, respectively, at a wavelength of 1550 nanometers as a function of MAC number (i.e., mode field diameter divided by cutoff wavelength) for various exemplary optical fibers in accordance with the standard IEC fixed-diameter sandpaper drum test (i.e., IEC TR62221, Method B). The respective attenuation data depicted in FIG. 11 (added loss) and FIG. 12 (microbend sensitivity) were obtained at 23° C. under the test conditions previously described with respect to FIG. 1 (i.e., 400-meter fiber samples were wound at about 2,940 mN (i.e., a tension of 300 gf) on a 300-mm diameter fiber spool wrapped with adhesive-backed, 40-micron grade sandpaper).
FIG. 11 shows that Draka Comteq's bend-resistant, single-mode glass fiber available under the trade name BendBright XS ® in combination with Draka Comteq's ColorLock XS brand coating system provides outstanding performance with respect to added loss.
FIG. 12 shows that Draka Comteq's bend-resistant, single-mode glass fiber available under the trade name BendBright XS ® in combination with Draka Comteq's ColorLock XS brand coating system provides superior microbend sensitivity (i.e., microbend sensitivity of 0.01 to 0.03 (dB/km)/(gf/mm)).
The optical fibers according to the present invention typically further include a tough secondary coating to protect the primary coating and glass fiber from damage during handling and installation. For example, the secondary coating might have a modulus of between about 800 MPa and 1,000 MPa (e.g., about 900 MPa) as measured on a standard 75-micron film. As disclosed herein, this secondary coating may be inked as a color code or, preferably, may be color-inclusive to provide identification without the need for a separate inking process.
In one embodiment according to the present invention, the secondary coating, which surrounds the primary coating to thereby protect the fiber structure, features an inclusive coloring system (i.e., not requiring an extra layer of ink to be added for color coding). The colors, which conform to Munsell standards for optical fiber color-coding, are enhanced for brightness and visibility under dim lighting (e.g., in deep shade or in confined spaces, such as manholes) and are easily distinguished against both light and dark backgrounds.
Furthermore, the secondary coating features a surface that provides an excellent interface with ribbon matrix material so that the matrix separates easily from the colored fiber in a way that does not sacrifice robustness. The mechanical properties of the colored secondary coating are balanced with those of the primary coating so that, in heat stripping, the coating/matrix composite separates cleanly from the glass fibers.
Employing Draka Comteq's bend-resistant, single-mode glass fiber available under the trade name BendBright XS ® (or the trade name BendBright-Elite™) with the present dual-coating system, which includes a low-modulus primary coating, has been found to reduce microbending sensitivity by between about one to two orders of magnitude relative to standard single-mode fiber (SSMF) at the key transmission frequencies of 1550 nanometers and 1625 nanometers. As noted, such optical fiber not only provides outstanding resistance to microbending and macrobending, but also complies with the ITU-T G.657.A/B and ITU-T G.652.D requirements.
In particular, Draka Comteq's bend-resistant, single-mode glass fiber available under the trade name BendBright XS ® (e.g., enhanced with Draka Comteq's ColorLock XS brand coating system) provides resistance to macrobending required for sustained bends having a radius as low as five (5) millimeters with an estimated failure probability of less than two (2) breaks per million full-circle bends (i.e., 360°) over 30 years in a properly protected environment. These bend-resistant optical fibers facilitate the rapid deployment of small, flexible cables for the delivery of fiber to the premises/business/home (i.e., FTTx) by virtue of the optical fiber's ability to sustain a loss-free transmission through small-radius bends. Cables employing such bend-resistant optical fibers may be routed around sharp bends, stapled to building frame, coiled, and otherwise employed in demanding environments while retaining clear and strong signal transmission.
In another aspect, the bend-insensitive optical fibers according to the present invention facilitate the reduction in overall optical-fiber diameter. As will be appreciated by those having ordinary skill in the art, a reduced-diameter optical fiber is cost-effective, requiring less raw material. Moreover, a reduced-diameter optical fiber requires less deployment space (e.g., within a buffer tube and/or fiber optic cable), thereby facilitating increased fiber count and/or reduced cable size.
Those having ordinary skill in the art will recognize that an optical fiber with a primary coating (and an optional secondary coating and/or ink layer) typically has an outer diameter of between about 235 microns and about 265 microns (μm). The component glass fiber itself (i.e., the glass core and surrounding cladding layers) typically has a diameter of about 125 microns, such that the total coating thickness is typically between about 55 microns and 70 microns.
With respect to the optical fiber according to the present invention, the component glass fiber typically has an outer diameter of about 125 microns. With respect to the optical fiber's surrounding coating layers, the primary coating typically has an outer diameter of between about 175 microns and about 195 microns (i.e., a primary coating thickness of between about 25 microns and 35 microns) and the secondary coating typically has an outer diameter of between about 235 microns and about 265 microns (i.e., a secondary coating thickness of between about 20 microns and 45 microns). Optionally, the optical fiber according to the present invention may include an outermost ink layer, which is typically between two and ten microns in thickness.
In one alternative embodiment, an optical fiber according to the present invention may possess a reduced diameter (e.g., an outermost diameter between about 150 microns and 230 microns). In this alternative optical fiber configuration, the thickness of the primary coating and/or secondary coating is reduced, while the diameter of the component glass fiber is maintained at about 125 microns. (Those having ordinary skill in the art will appreciate that, unless otherwise specified, diameter measurements refer to outer diameters.)
In such exemplary embodiments, the primary coating layer may have an outer diameter of between about 135 microns and about 175 microns (e.g., about 160 microns), typically less than 165 microns (e.g., between about 135 microns and 150 microns), and usually more than 140 microns (e.g., between about 145 microns and 155 microns, such as about 150 microns). Moreover, in such exemplary embodiments, the secondary coating layer may have an outer diameter of between about 150 microns and about 230 microns (e.g., more than about 165 microns, such as 190-210 microns or so), typically between about 180 microns and 200 microns. In other words, the total diameter of the optical fiber is reduced to less than about 230 microns (e.g., between about 195 microns and 205 microns, and especially about 200 microns).
One exemplary optical-fiber embodiment employs a secondary coating of about 197 microns at a tolerance of +/−5 microns (i.e., a secondary-coating outer diameter of between 192 microns and 202 microns). Typically, the secondary coating will retain a thickness of at least about 10 microns (e.g., an optical fiber having a reduced-thickness secondary coating of between 15 microns and 25 microns).
In accordance with the foregoing, a particular reduced-diameter, optical-fiber embodiment having exceptionally low losses employs Draka Comteq's 125-micron single-mode glass fiber available under the trade name BendBright XS ® with a 155-micron-diameter, low-modulus primary coating layer (e.g., Draka Comteq's ColorLock XS brand coating system) and a secondary coating (e.g., a nominal 200-micron-diameter secondary coating). As noted, BendBright XS ® bend-insensitive optical fiber complies with the ITU-T G.657.A/B and ITU-T G.652.D requirements. In this optical-fiber embodiment, the maximum tolerance with respect to the primary-coating thickness is +/−5 microns (i.e., a primary-coating outer diameter of between 150 microns and 160 microns), more typically about +/−2.5 microns (i.e., a primary-coating outer diameter of between about 152.5 microns and 157.5 microns).
Another particular reduced-diameter, optical-fiber embodiment having exceptionally low losses employs Draka Comteq's 125-micron single-mode glass fiber available under the trade name BendBright-Elite™ with a 155-micron-diameter, low-modulus primary coating layer (e.g., Draka Comteq's ColorLock XS brand coating system) and a secondary coating (e.g., a nominal 200-micron-diameter secondary coating). Like BendBright XS ® bend-insensitive optical fiber, BendBright-Elite™ bend-insensitive optical fiber complies with the ITU-T G.657.A/B and ITU-T G.652.D requirements. In this optical-fiber embodiment, the maximum tolerance with respect to the primary-coating thickness is +/−5 microns (i.e., a primary-coating outer diameter of between 150 microns and 160 microns), more typically about +/−2.5 microns (i.e., a primary-coating outer diameter of between about 152.5 microns and 157.5 microns).
The synergistic combination of (i) Draka Comteq's BendBright XS ® bend-insensitive single-mode glass fiber (or Draka Comteq's BendBright-Elite™ bend-insensitive glass fiber) and (ii) Draka Comteq's ColorLock XS brand coating system promotes significant reductions in optical-fiber diameter.
By way of example, Draka Comteq's 125-micron BendBright XS ® bend-insensitive single-mode glass fiber in combination with a 155-micron-diameter, low-modulus primary coating layer (e.g., Draka Comteq's ColorLock XS brand coating system) and a 200-micron-diameter secondary coating layer provides (i) comparable microbending performance to that of a 125-micron, standard single-mode glass fiber coated with a 185-micron-diameter, low-modulus primary coating layer (e.g., Draka Comteq's ColorLock XS brand coating system) and a 242-micron-diameter secondary coating layer and (ii) significantly better microbending performance than that of a standard single-mode optical fiber (SSMF) that employs conventional primary and secondary coatings (i.e., at an outer diameter of about 235-265 microns).
As noted previously, one suitable composition for the primary coating is a UV-curable urethane acrylate product provided by DSM Desotech (Elgin, Ill.) under the trade name DeSolite® DP 1011. It is believed that this UV-curable urethane acrylate product includes about 1.0 percent of adhesion promoter. Other suitable compositions for the primary coating include alternative UV-curable urethane acrylate products provided by DSM Desotech under various trade names, including DeSolite® DP 1014, DeSolite® DP 1014XS, and DeSolite® DP 1016. It is believed that these alternative compositions possess essentially the same low-modulus and glass-transition properties as those possessed by the aforementioned DeSolite® DP 1011 UV-curable urethane acrylate product, albeit with some compositional variation (e.g., adhesion promoter concentration increased to 1.25 percent). As will be appreciated by those having ordinary skill in the art, compositional variations may provide particular primary-coating properties that are desirable for particular applications. It appears that the DeSolite® DP 1014XS UV-curable urethane acrylate product, for instance, exhibits favorable processing characteristics and provides improved delamination resistance.
Those having ordinary skill in the art will appreciate that each of these exemplary UV-curable urethane acrylate products (i.e., DeSolite® DP 1011, DeSolite® DP 1014, DeSolite® DP 1014XS, and DeSolite® DP 1016) provides better microbending performance than do conventional primary coatings, such as other UV-curable urethane acrylate products provided by DSM Desotech under the respective trade names DeSolite® DP 1004 and DeSolite® DP 1007.
Example 7
Comparison of Microbending Sensitivity
The respective microbend sensitivities were further measured for exemplary optical fibers, including (i) an enhanced single-mode glass fiber (ESMF) with a low-modulus coating, (ii) various bend-insensitive glass fibers (e.g., Draka Comteq's single-mode glass fibers available under the trade names BendBright XS ®) with conventional primary coatings, and (iii) various bend-insensitive glass fibers and macrobend-resistant glass fibers (e.g., Draka Comteq's single-mode glass fibers available under the trade names BendBright XS ® and BendBright®) with low-modulus primary coatings.
The testing procedure for Example 7 was an adaptation of IEC TR62221, Method B, which, as noted, is incorporated by reference in its entirety. For this modified IEC fixed-diameter sandpaper drum test, a 300-millimeter diameter quartz cylinder was wrapped with adhesive-backed, 320-grit sandpaper (i.e., approximately equivalent to 36-micron-grade sandpaper) to create a rough surface—albeit a finer surface than the surfaces employed in Examples 3-6. Then, each 440-meter fiber sample was wound in a single layer at about 1,470 mN (i.e., a controlled tension of 150 gf on the 300-millimeter diameter quartz drum using a Delachaux optical fiber winding apparatus). For the sake of convenience, this particular modification of the IEC TR62221, Method B, is herein referred to as the “Reduced-Diameter Optical-Fiber Microbend Sensitivity Test.”
Two hours after winding, fiber attenuation was measured at room temperature (i.e., 23° C.) using an optical time domain reflectometer (OTDR). Then, the drum (with 440 meters of wound fiber) was temperature cycled in a temperature-controlled chamber from about room temperature through (i) −40° C. and (ii) −60° C. Fiber attenuation was measured by an optical time domain reflectometer (OTDR) after two hours of equilibration at both −40° C. and −60° C.
Absolute fiber attenuation measured at a wavelength of 1550 nanometers is provided (below) in Table 2.
TABLE 2
(Microbend Sensitivity - 1550 nm)
Optical Fiber
glass fiber w/primary coating
23° C.
−40° C.
−60° C.
Ex.
(glass fiber and coating diameters)
(dB/km)
(dB/km)
(dB/km)
200-micron bend-insensitive SMFs with
low-modulus primary coatings
A
BendBright XS ® w/DP1014XS
1.114
1.019
1.002
(125μ/155μ/199μ)
B
BendBright XS ® w/DP1014XS
1.786
1.612
1.542
(125μ/150μ/199μ)
C
BendBright XS ® w/DP1016
1.488
1.367
1.536
(125μ/150μ/199μ)
200-micron bend-insensitive SMFs with
conventional primary coatings
D
BendBright XS ® w/DSM 950-076
2.726
3.215
3.595
(125μ/160μ/199μ)
E
BendBright XS ® w/DSM 950-076
4.288
4.766
5.150
(125μ/150μ/199μ)
200-micron macrobend-resistant SMFs with
low-modulus primary coatings
F
BendBright ® w/DP1014XS
4.683
4.348
4.878
(125μ/150μ/199μ)
G
BendBright ® w/DP1016
5.985
5.800
6.399
(125μ/150μ/199μ)
242-micron enhanced SMF with low-modulus primary coatings
H
ESMF w/DP1014
0.705
0.663
0.648
(125μ/190μ/242μ)
Table 2 (above) shows that Draka Comteq's 125-micron BendBright XS ® bend-insensitive single-mode glass fiber facilitates a reduction in total optical-fiber diameter by permitting use of thinner primary and/or secondary coatings. In this regard, a 200-micron optical fiber using Draka Comteq's BendBright XS ® bend-insensitive single-mode glass fiber and relatively thin primary and secondary coatings provides microbending performance that approaches that of a 242-micron optical fiber having an enhanced standard single-mode fiber (ESMF) and thicker layers of comparable low-modulus primary and secondary coatings.
Absolute fiber attenuation measured at a wavelength of 1310 nanometers is provided (below) in Table 3:
TABLE 3
(Microbend Sensitivity - 1310 nm)
Optical Fiber
glass fiber w/primary coating
23° C.
−40° C.
−60° C.
Ex.
(glass fiber and coating diameters)
(dB/km)
(dB/km)
(dB/km)
200-micron bend-insensitive SMFs with
low-modulus primary coatings
A
BendBright XS ® w/DP1014XS
0.954
0.869
0.758
(125μ/155μ/199μ)
B
BendBright XS ® w/DP1014XS
1.574
1.426
1.478
(125μ/150μ/199μ)
C
BendBright XS ® w/DP1016
1.496
1.381
1.509
(125μ/150μ/199μ)
200-micron bend-insensitive SMFs with
conventional primary coatings
D
BendBright XS ® w/DSM 950-076
2.238
2.683
3.015
(125μ/160μ/199μ)
E
BendBright XS ® w/DSM 950-076
4.020
4.363
4.671
(125μ/150μ/199μ)
200-micron macrobend-resistant SMFs with
low-modulus primary coatings
F
BendBright ® w/DP1014XS
2.670
2.447
2.761
(125μ/150μ/199μ)
G
BendBright ® w/DP1016
3.725
3.550
3.927
(125μ/150μ/199μ)
The comparative 200-micron optical fiber designated Example D in Tables 2 and 3 (above) employed the secondary coating used in Draka Comteq's ColorLock XS brand coating system, albeit with a conventional primary coating. The comparative 200-micron optical fiber designated Example E in Tables 2 and 3 (above) employed both a conventional primary coating (i.e., DSM 950-076) and a conventional secondary coating (i.e., DSM 950-044).
Tables 2 and 3 (above) indicate that, all things being equal, the low-modulus primary coatings according to the present invention (e.g., Draka Comteq's ColorLock XS brand coating system) provide better microbending performance than do conventional coating systems. This superior microbending performance is especially important when employing a primary-coating layer at a significantly reduced thickness on a 125-micron glass fiber in order to achieve a nominal 200-micron optical fiber.
Moreover, Tables 2 and 3 (above) indicate that, all things being equal, Draka Comteq's single-mode glass fibers available under the trade name BendBright XS ®, which employ a trench-assisted design, provide better microbending performance than do single-mode fibers that do not employ trench-assisted and/or void-assisted design (e.g., Draka Comteq's single-mode glass fibers available under the trade name BendBright®). This is somewhat unexpected—trench-assisted and other bend-insensitive glass designs are generally understood to have more pronounced effects upon macrobending rather than microbending.
Example 8
Comparison of Microbend Sensitivity
The respective microbend sensitivities were further measured in accordance with the IEC fixed-diameter sandpaper drum test (i.e., IEC TR62221, Method B) for exemplary optical fibers, including (i) enhanced single-mode glass fibers (ESMF) with Draka Comteq's ColorLock brand coating system and (ii) Draka Comteq's single-mode glass fibers available under the trade name BendBright XS ® with Draka Comteq's improved ColorLock XS brand coating system.
As with Example 7 (above), the testing procedure for Example 8 was likewise an adaptation of IEC TR62221, Method B (i.e., the “Reduced-Diameter Optical-Fiber Microbend Sensitivity Test”). For this modified IEC fixed-diameter sandpaper drum test, a 300-millimeter diameter quartz cylinder was wrapped with adhesive-backed, 320-grit sandpaper (i.e., approximately equivalent to 36-micron-grade sandpaper) to create a rough surface. Then, each 440-meter fiber sample was wound in a single layer at about 1,470 mN (i.e., a controlled tension of 150 gf on the 300-millimeter diameter quartz drum using a Delachaux optical fiber winding apparatus). Two hours after winding, fiber attenuation was measured at room temperature (i.e., 23° C.) using an optical time domain reflectometer (OTDR).
Absolute fiber attenuation measured at a wavelength of 1550 nanometers is provided (below) in Table 4.
TABLE 4
(Microbend Sensitivity - 1550 nm)
Optical Fiber
glass fiber w/primary coating
23° C.
Ex.
(glass fiber and coating diameters)
(dB/km)
nominal 200-micron bend-insensitive SMFs with
low-modulus primary coatings
A
BendBright XS ® w/DP1014XS
0.97
(125μ/153μ/194μ)
B
BendBright XS ® w/DP1014XS
0.98
(125μ/154μ/197μ)
C
BendBright XS ® w/DP1014XS
1.05
(125μ/154μ/198μ)
D
BendBright XS ® w/DP1014XS
0.74
(125μ/158μ/200μ)
E
BendBright XS ® w/DP1014XS
0.70
(125μ/160μ/201μ)
242-micron enhanced SMFs with conventional primary coatings
F
ESMF w/DP1007
2.004
(125μ/190μ/242μ)
G
ESMF w/DP1007
1.661
(125μ/190μ/242μ)
H
ESMF w/DP1007
1.542
(125μ/190μ/242μ)
I
ESMF w/DP1007
1.568
(125μ/190μ/242μ)
J
ESMF w/DP1007
1.973
(125μ/190μ/242μ)
Table 4 (above) shows that, Draka Comteq's 125-micron BendBright XS ® bend-insensitive single-mode glass fiber in combination with (i) a low-modulus primary coating having an outer diameter of between about 150 microns and 160 microns and (ii) a secondary coating having an outer diameter of between about 195 microns and 200 microns provides significantly better microbending performance compared with that of conventional 125-micron enhanced single-mode glass fiber (ESMF) in combination with a 190-micron-diameter, conventional primary coating and a 242-micron-diameter, conventional secondary coating.
Stated otherwise, a nominal 200-micron optical fiber formed from Draka Comteq's 125-micron BendBright XS ® bend-insensitive single-mode glass fiber and Draka Comteq's ColorLock XS brand coating system provides superior microbending performance to that of a 242-micron, enhanced single-mode optical fiber (ESMF) that employs conventional primary and secondary coatings.
Moreover, a nominal 200-micron optical fiber formed from Draka Comteq's 125-micron BendBright XS ® bend-insensitive single-mode glass fiber and Draka Comteq's ColorLock XS brand coating system provides similar microbending performance to that of a 242-micron, enhanced single-mode optical fiber (ESMF) that employs a comparable low-modulus primary coating and a comparable secondary coating. By way of example, the 200-micron optical fibers designated Examples A-E in Table 4 (above) provide comparable microbending performance to that of the 242-micron optical fiber designated Example H in Table 2 (above), which, as noted, is a 242-micron optical fiber having an enhanced standard single-mode fiber (ESMF) and thicker layers of comparable low-modulus primary and secondary coatings.
As noted, whereas single-mode glass fibers that are commercially available from Draka Comteq under the trade name BendBright® are compliant with the ITU-T G.652.D requirements, single-mode glass fibers that are commercially available from Draka Comteq under the trade names BendBright XS ® and BendBright-Elite™ are compliant with the ITU-T G.652.D requirements and the ITU-T G.657.A/B requirements. The respective ITU-T G.652 recommendations and the respective ITU-T G.657 recommendations are hereby incorporated by reference in their entirety. Table 5 (below) depicts fiber attributes specified by the ITU-T G.657.A/B recommendations.
TABLE 5
(ITU-T G.657.A/B Fiber Attributes)
Attribute
Detail
G.657.A Value
G.657.B Value
Mode Field Diameter
Wavelength (nm)
1310
1310
Range of Nominal Values
8.6-9.5
6.3-9.5
(μm)
Tolerance (μm)
±0.4
±0.4
Cladding Diameter
Nominal (μm)
125
125
Tolerance (μm)
±0.7
±0.7
Core Concentricity Error
Maximum (μm)
0.5
0.5
Cladding Non-Circularity
Maximum (%)
1.0
1.0
Cable Cut-Off
Maximum (nm)
1260
1260
Wavelength
Macrobending Loss
Radius (mm)
15
10
15
10
7.5
Number of Turns
10
1
10
1
1
Maximum @1550 nm (dB)
0.25
0.75
0.03
0.1
0.5
Maximum @1625 nm (dB)
1.0
1.5
0.1
0.2
1.0
Proof Stress
Minimum (GPa)
0.69
0.69
Chromatic Dispersion
λ 0 min (nm)
1300
1300
Coefficient
λ 0 max (nm)
1324
1420
S 0 max (ps/(nm 2 · km))
≦0.092
≦0.10
In this regard, this application incorporates by reference product specifications for the following Draka Comteq single-mode optical fibers: (i) Enhanced Single Mode Fiber (ESMF); (ii) BendBright® single-mode optical fiber; (iii) BendBright XS ® single-mode optical fiber; and (iv) BendBright-Elite™ single-mode optical fiber. This technical information is provided as Appendices 1-4, respectively, in priority U.S. Provisional Application No. 61/248,319 for a Reduced-Diameter Optical Fiber (filed Oct. 2, 2009), which, as noted, is incorporated by reference in its entirety.
It is within the scope of the present invention to achieve reduced-diameter optical fibers by employing other kinds of trench-assisted, bend-insensitive glass fibers. In this regard, U.S. Patent Application Publication No. US 2008/0056654 A1 for a for a Low Bend Loss Single-Mode Optical Fiber (Bickham et al.), which is hereby incorporated by reference in its entirety, discloses a glass fiber that includes a cladding region with a depressed refractive index.
Furthermore, it is within the scope of the present invention to achieve reduced-diameter optical fibers by employing bend-insensitive glass fibers that include regular or random holes, whether continuous or discrete, in an annular region (e.g., an inner cladding). In this regard, U.S. Pat. No. 7,444,838 for a Holey Optical Fiber with Random Pattern of Holes and Method for Making the Same (Pickrell et al.) and U.S. Pat. No. 7,567,742 for a Holey Optical Fiber with Random Pattern of Holes and Method for Making Same (Pickrell et al.), each of which is hereby incorporated by reference in its entirety, disclose a glass fiber that includes a holey region (e.g., a cladding) with a random array of holes. Similarly, U.S. Pat. No. 7,450,806 for Microstructured Optical Fibers and Methods (Bookbinder et al.), which is hereby incorporated by reference in its entirety, discloses a microstructured glass fiber that includes voids within the cladding region.
Other trench-assisted and/or void-assisted optical fibers are disclosed in the following patents and patent application publications, each of which is hereby incorporated by reference in its entirety: U.S. Pat. No. 4,852,968 for an Optical Fiber Comprising a Refractive Index Trench (Reed); U.S. Pat. No. 5,044,724 for a Method of Producing Optical Fiber, and Fiber Produced by the Method (Glodis et al.); U.S. Pat. No. 6,901,197 for a Microstructured Optical Fiber (Hasegawa et al.); U.S. Pat. No. 7,095,940 for an Optical Fiber, Method for Manufacturing Same and Optical Transmission Channel (Hayami et al.); U.S. Pat. No. 7,228,040 for a Hole-Assisted Single Mode Optical Fiber (Nakajima et al.); U.S. Pat. No. 7,239,784 for an Optical Fiber, Method for Manufacturing Same and Optical Transmission Channel (Hayami et al.); U.S. Pat. No. 7,292,762 for a Hole-Assisted Holey Fiber and Low Bending Loss Multimode Holey Fiber (Guan et al.); U.S. Pat. No. 7,433,566 for a Low Bend Loss Optical Fiber with High Modulus Coating (Bookbinder et al.); U.S. Pat. No. 7,526,166 for a High Numerical Aperture Fiber (Bookbinder et al.); U.S. Pat. No. 7,526,169 for a Low Bend Loss Quasi-Single-Mode Optical Fiber and Optical Fiber Line (Bickham et al.); U.S. Pat. No. 7,555,187 for a Large Effective Area Fiber (Bickham et al.); U.S. Pat. No. 7,450,807 for a Low Bend Loss Optical Fiber with Deep Depressed Ring (Bickham et al.); U.S. Pat. No. 7,574,088 for an Optical Fiber and Optical Fiber Ribbon, and Optical Interconnection System (Sugizaki et al.); U.S. Patent Application Publication No. US 2008/0166094 A1 for a Bend Resistant Multimode Optical Fiber (Bickham et al.); U.S. Patent Application Publication No. US 2008/0304800 A1 for an Optical Fiber with Large Effective Area (Bickham et al.); U.S. Patent Application Publication No. US 2009/0060437 A1 for Bend Insensitivity in Single Mode Optical Fibers (Fini et al.); U.S. Patent Application Publication No. US 2009/0126407 A1 for Methods for Making Optical Fiber Preforms and Microstructured Optical Fibers (Bookbinder et al.); U.S. Patent Application Publication No. US 2009/0154888 A1 for a Bend Resistant Multimode Optical Fiber (Steele et al.); U.S. Patent Application Publication No. US 2009/0169163 A1 for a Bend Resistant Multimode Optical Fiber (Steele et al.); and International Patent Application Publication No. WO 2009/064381 A1 for Methods for Making Optical Fiber Preforms and Microstructured Optical Fibers (Bookbinder et al.).
It is believed that the foregoing glass fibers, as well as other glass fibers disclosed in previously incorporated-by-reference patent documents, might be combined with the low-modulus primary coatings as herein disclosed to achieve satisfactory, reduced-diameter optical fibers. As such, the resulting reduced-diameter optical fibers (e.g., holey fibers with low-modulus primary coatings) are within the scope of the present invention.
That said, it has been preliminarily observed that, with respect to reduced-diameter optical fibers having low-modulus primary coatings, bend-insensitive glass fibers having full-solid designs (e.g., 125-micron BendBright XS ® bend-insensitive single-mode glass fiber) seem to provide better microbending performance than do bend-insensitive glass fibers having hole-assisted designs.
Furthermore, it has been preliminarily observed that, with respect to reduced-diameter optical fibers, bend-insensitive glass fibers having full-solid designs (e.g., 125-micron BendBright XS ® bend-insensitive single-mode glass fiber) also seem to provide better mechanical performance than do bend-insensitive glass fibers having void-assisted designs (e.g., holey fibers). Those having ordinary skill in the art will appreciate that mechanical robustness is an important consideration when employing a bend-insensitive glass fiber within a nominal 200-micron optical fiber.
In this regard, 200-micron optical fibers that are formed from (i) Draka Comteq's 125-micron BendBright XS ® bend-insensitive single-mode glass fiber, which has a full-solid glass design, and (ii) Draka Comteq's ColorLock XS brand coating system demonstrate comparable mechanical reliability to that of a standard 242-micron optical fiber (e.g., a SSMF).
The 200-micron optical fibers that are formed from Draka Comteq's 125-micron BendBright XS ® bend-insensitive single-mode glass fiber and Draka Comteq's ColorLock XS brand coating system were tested for tensile strength and dynamic fatigue in accordance with the FOTP-28 standard, which is hereby incorporated by reference in its entirety. Representative mechanical reliability for these 200-micron optical fibers, which possessed differently colored secondary coatings, is provided (below) in Table 6.
TABLE 6
(Mechanical Reliability)
Tensile Strength
Tensile Strength
Dynamic
50% failure
15% failure
Fatigue
ColorLock XS color
(kpsi)
(kpsi)
(n-value)
Blue
711
539
22.5
Orange
712
626
22.0
Green
705
600
20.4
Brown
675
557
20.8
Slate
721
623
22.8
White
729
577
21.8
Red
708
577
20.9
Black
709
627
22.8
Yellow
715
540
21.4
Violet
713
580
21.6
Rose
723
557
21.9
Aqua
730
580
23.0
As will be understood by those having ordinary skill in the art, industry minimum requirements for tensile strength at fiber failure are 550 kpsi at the 50 th percentile of the optical-fiber tensile-strength distribution (i.e., the median tensile strength) and 455 kpsi at the 15 th percentile of the optical-fiber tensile-strength distribution.
The industry minimum requirement for the dynamic fatigue stress corrosion factor (n-value) is 18. In this regard, dynamic fatigue stress corrosion factor provides an indication of how fast a flaw in the glass fiber's silica structure propagates under strain.
As will be further understood by those having ordinary skill in the art, for both tensile strength and dynamic fatigue stress corrosion factor, an adequate sampling of optical fibers (e.g., n=30) provides a statistical estimate that facilitates characterization the optical-fiber population.
In another alternative embodiment, the outer diameter of the component glass fiber may be reduced to less than 125 microns (e.g., between about 60 microns and 120 microns), perhaps between about 70 microns and 115 microns (e.g., about 80-110 microns). This may be achieved, for instance, by reducing the thickness of one or more cladding layers.
As compared with the prior alternative embodiment, (i) the total diameter of the optical fiber may be reduced (i.e., the thickness of the primary and secondary coatings are maintained in accordance with the prior alternative embodiment) or (ii) the respective thicknesses of the primary and/or secondary coatings may be increased relative to the prior alternative embodiment (e.g., such that the total diameter of the optical fiber might be maintained).
By way of illustration, with respect to the former, a component glass fiber having a diameter of between about 90 and 100 microns might be combined with a primary coating layer having an outer diameter of between about 110 microns and 150 microns (e.g., about 125 microns) and a secondary coating layer having an outer diameter of between about 130 microns and 190 microns (e.g., about 155 microns). With respect to the latter, a component glass fiber having a diameter of between about 90 and 100 microns might be combined with a primary coating layer having an outer diameter of between about 120 microns and 140 microns (e.g., about 130 microns) and a secondary coating layer having an outer diameter of between about 160 microns and 230 microns (e.g., about 195-200 microns).
It seems that reducing the diameter of the component glass fiber might make the resulting optical fiber more susceptible to microbending attenuation. For example, as compared with a component glass fiber having a standard diameter of 125 microns, a component glass fiber having a diameter of 110 microns might be twice as susceptible to microbending losses. That said, the advantages of further reducing optical-fiber diameter may be worthwhile for some optical-fiber applications.
In view of the foregoing, commonly assigned U.S. Patent Application No. 61/177,996 for a Reduced-Diameter Optical Fiber, filed May 13, 2009, (Overton) and U.S. Patent Application No. 61/248,319 for a Reduced-Diameter Optical Fiber, filed Oct. 2, 2009, (Overton) are hereby incorporated by reference in their entirety.
As noted, the optical fiber according to the present invention may include one or more coating layers (e.g., a primary coating and a secondary coating). At least one of the coating layers—typically the secondary coating—may be colored and/or possess other markings to help identify individual fibers. Alternatively, a tertiary ink layer may surround the primary and secondary coatings.
As discussed previously, combining (i) a coating system according to the present invention with (ii) a glass fiber having a refractive index profile that itself provides bend resistance (e.g., low macrobending sensitivity) has been found to provide unexpectedly superior reductions in microbend sensitivity. Indeed, bend-insensitive glass fibers are especially suitable for use with the coating system of the present invention (e.g., Draka Comteq's ColorLock XS brand coating system).
The present optical fiber may be deployed in various structures, such as those exemplary structures disclosed hereinafter.
For example, one or more of the present optical fibers may be enclosed within a buffer tube. For instance, optical fiber may be deployed in either a single-fiber loose buffer tube or a multi-fiber loose buffer tube. With respect to the latter, multiple optical fibers may be bundled or stranded within a buffer tube or other structure. In this regard, within a multi-fiber loose buffer tube, fiber sub-bundles may be separated with binders (e.g., each fiber sub-bundle is enveloped in a binder). Moreover, fan-out tubing may be installed at the termination of such loose buffer tubes to directly terminate loose buffered optical fibers with field-installed connectors.
In other embodiments, the buffer tube may tightly surround the outermost optical fiber coating (i.e., tight buffered fiber) or otherwise surround the outermost optical-fiber coating or ink layer to provide an exemplary radial clearance of between about 50 and 100 microns (i.e., a semi-tight buffered fiber).
With respect to the former tight buffered fiber, the buffering may be formed by coating the optical fiber with a curable composition (e.g., a UV-curable material) or a thermoplastic material. The outer diameter of tight buffer tubes, regardless of whether the buffer tube is formed from a curable or non-curable material, is typically less than about 1,000 microns (e.g., either about 500 microns or about 900 microns).
With respect to the latter semi-tight buffered fiber, a lubricant may be included between the optical fiber and the buffer tube (e.g., to provide a gliding layer).
As will be known by those having ordinary skill in the art, an exemplary buffer tube enclosing optical fibers as disclosed herein may be formed of polyolefins (e.g., polyethylene or polypropylene), including fluorinated polyolefins, polyesters (e.g., polybutylene terephthalate), polyamides (e.g., nylon), as well as other polymeric materials and blends. In general, a buffer tube may be formed of one or more layers. The layers may be homogeneous or include mixtures or blends of various materials within each layer.
In this context, the buffer tube may be extruded (e.g., an extruded polymeric material) or pultruded (e.g., a pultruded, fiber-reinforced plastic). By way of example, the buffer tube may include a material to provide high temperature and chemical resistance (e.g., an aromatic material or polysulfone material).
Although buffer tubes typically have a circular cross section, buffer tubes alternatively may have an irregular or non-circular shape (e.g., an oval or a trapezoidal cross-section).
Alternatively, one or more of the present optical fibers may simply be surrounded by an outer protective sheath or encapsulated within a sealed metal tube. In either structure, no intermediate buffer tube is necessarily required.
Multiple optical fibers as disclosed herein may be sandwiched, encapsulated, and/or edge bonded to form an optical fiber ribbon. Optical fiber ribbons can be divisible into subunits (e.g., a twelve-fiber ribbon that is splittable into six-fiber subunits). Moreover, a plurality of such optical fiber ribbons may be aggregated to form a ribbon stack, which can have various sizes and shapes.
For example, it is possible to form a rectangular ribbon stack or a ribbon stack in which the uppermost and lowermost optical fiber ribbons have fewer optical fibers than those toward the center of the stack. This construction may be useful to increase the density of optical elements (e.g., optical fibers) within the buffer tube and/or cable.
In general, it is desirable to increase the filling of transmission elements in buffer tubes or cables, subject to other constraints (e.g., cable or mid-span attenuation). The optical elements themselves may be designed for increased packing density. For example, the optical fiber may possess modified properties, such as improved refractive-index profile, core or cladding dimensions, or primary-coating thickness and/or modulus, to improve microbending and macrobending characteristics.
By way of example, a rectangular ribbon stack may be formed with or without a central twist (i.e., a “primary twist”). Those having ordinary skill in the art will appreciate that a ribbon stack is typically manufactured with rotational twist to allow the tube or cable to bend without placing excessive mechanical stress on the optical fibers during winding, installation, and use. In a structural variation, a twisted (or untwisted) rectangular ribbon stack may be further formed into a coil-like configuration (e.g., a helix) or a wave-like configuration (e.g., a sinusoid). In other words, the ribbon stack may possess regular “secondary” deformations.
As will be known to those having ordinary skill in the art, such optical fiber ribbons may be positioned within a buffer tube or other surrounding structure, such as a buffer-tube-free cable. Subject to certain restraints (e.g., attenuation) it is desirable to increase the density of elements such as optical fibers or optical fiber ribbons within buffer tubes and/or optical fiber cables.
A plurality of buffer tubes containing optical fibers (e.g., loose or ribbonized fibers) may be positioned externally adjacent to and stranded around a central strength member. This stranding can be accomplished in one direction, helically, known as “S” or “Z” stranding, or Reverse Oscillated Lay stranding, known as “S-Z” stranding. Stranding about the central strength member reduces optical fiber strain when cable strain occurs during installation and use.
Those having ordinary skill in the art will understand the benefit of minimizing fiber strain for both tensile cable strain and longitudinal compressive cable strain during installation or operating conditions.
With respect to tensile cable strain, which may occur during installation, the cable will become longer while the optical fibers can migrate closer to the cable's neutral axis to reduce, if not eliminate, the strain being translated to the optical fibers. With respect to longitudinal compressive strain, which may occur at low operating temperatures due to shrinkage of the cable components, the optical fibers will migrate farther away from the cable's neutral axis to reduce, if not eliminate, the compressive strain being translated to the optical fibers.
In a variation, two or more substantially concentric layers of buffer tubes may be positioned around a central strength member. In a further variation, multiple stranding elements (e.g., multiple buffer tubes stranded around a strength member) may themselves be stranded around each other or around a primary central strength member.
Alternatively, a plurality of buffer tubes containing optical fibers (e.g., loose or ribbonized fibers) may be simply placed externally adjacent to the central strength member (i.e., the buffer tubes are not intentionally stranded or arranged around the central strength member in a particular manner and run substantially parallel to the central strength member).
Alternatively still, the present optical fibers may be positioned within a central buffer tube (i.e., the central buffer tube cable has a central buffer tube rather than a central strength member). Such a central buffer tube cable may position strength members elsewhere. For instance, metallic or non-metallic (e.g., GRP) strength members may be positioned within the cable sheath itself, and/or one or more layers of high-strength yarns (e.g., aramid or non-aramid yarns) may be positioned parallel to or wrapped (e.g., contrahelically) around the central buffer tube (i.e., within the cable's interior space). Likewise, strength members can be included within the buffer tube's casing.
In other embodiments, the optical fibers may be placed within a slotted core cable. In a slotted core cable, optical fibers, individually or as a fiber ribbon, may be placed within pre-shaped helical grooves (i.e., channels) on the surface of a central strength member, thereby forming a slotted core unit. The slotted core unit may be enclosed by a buffer tube. One or more of such slotted core units may be placed within a slotted core cable. For example, a plurality of slotted core units may be helically stranded around a central strength member.
Alternatively, the optical fibers may also be stranded in a maxitube cable design, whereby the optical fibers are stranded around themselves within a large multi-fiber loose buffer tube rather than around a central strength member. In other words, the large multi-fiber loose buffer tube is centrally positioned within the maxitube cable. For example, such maxitube cables may be deployed in optical ground wires (OPGW).
In another cabling embodiment, multiple buffer tubes may be stranded around themselves without the presence of a central member. These stranded buffer tubes may be surrounded by a protective tube. The protective tube may serve as the outer casing of the fiber optic cable or may be further surrounded by an outer sheath. The protective tube may tightly or loosely surround the stranded buffer tubes.
As will be known to those having ordinary skill in the art, additional elements may be included within a cable core. For example, copper cables or other active, transmission elements may be stranded or otherwise bundled within the cable sheath. Passive elements may also be placed within the cable core, such as between the interior walls of the buffer tubes and the enclosed optical fibers. Alternatively and by way of example, passive elements may be placed outside the buffer tubes between the respective exterior walls of the buffer tubes and the interior wall of the cable jacket, or, within the interior space of a buffer-tube-free cable.
For example, yarns, nonwovens, fabrics (e.g., tapes), foams, or other materials containing water-swellable material and/or coated with water-swellable materials (e.g., including super absorbent polymers (SAPs), such as SAP powder) may be employed to provide water blocking and/or to couple the optical fibers to the surrounding buffer tube and/or cable jacketing (e.g., via adhesion, friction, and/or compression). Exemplary water-swellable elements are disclosed in commonly assigned U.S. Pat. No. 7,515,795 for a Water-Swellable Tape, Adhesive-Backed for Coupling When Used Inside a Buffer Tube (Overton et al.), which is hereby incorporated by reference in its entirety.
Moreover, an adhesive (e.g., a hot-melt adhesive or curable adhesive, such as a silicone acrylate cross-linked by exposure to actinic radiation) may be provided on one or more passive elements (e.g., water-swellable material) to bond the elements to the buffer tube. An adhesive material may also be used to bond the water-swellable element to optical fibers within the buffer tube. Exemplary arrangements of such elements are disclosed in commonly assigned U.S. Pat. No. 7,599,589 for a Gel-Free Buffer Tube with Adhesively Coupled Optical Element (Overton et al.), which is hereby incorporated by reference in its entirety.
The buffer tubes (or buffer-tube-free cables) may also contain a thixotropic composition (e.g., grease or grease-like gels) between the optical fibers and the interior walls of the buffer tubes. For example, filling the free space inside a buffer tube with water-blocking, petroleum-based filling grease helps to block the ingress of water. Further, the thixotropic filling grease mechanically (i.e., viscously) couples the optical fibers to the surrounding buffer tube.
Such thixotropic filling greases are relatively heavy and messy, thereby hindering connection and splicing operations. Thus, the present optical fibers may be deployed in dry cable structures (i.e., grease-free buffer tubes).
Exemplary buffer tube structures that are free from thixotropic filling greases are disclosed in commonly assigned U.S. Patent Application Publication No. US2009/0003785 A1 for a Coupling Composition for Optical Fiber Cables (Parris et al.), which is hereby incorporated by reference in its entirety. Such buffer tubes employ coupling compositions formed from a blend of high-molecular weight elastomeric polymers (e.g., about 35 weight percent or less) and oils (e.g., about 65 weight percent or more) that flow at low temperatures. Unlike thixotropic filling greases, the coupling composition (e.g., employed as a cohesive gel or foam) is typically dry and, therefore, less messy during splicing.
As will be understood by those having ordinary skill in the art, a cable enclosing optical fibers as disclosed herein may have a sheath formed from various materials in various designs. Cable sheathing may be formed from polymeric materials such as, for example, polyethylene, polypropylene, polyvinyl chloride (PVC), polyamides (e.g., nylon), polyester (e.g., PBT), fluorinated plastics (e.g., perfluoroethylene propylene, polyvinyl fluoride, or polyvinylidene difluoride), and ethylene vinyl acetate. The sheath and/or buffer tube materials may also contain other additives, such as nucleating agents, flame-retardants, smoke-retardants, antioxidants, UV absorbers, and/or plasticizers.
The cable sheathing may be a single jacket formed from a dielectric material (e.g., non-conducting polymers), with or without supplemental structural components that may be used to improve the protection (e.g., from rodents) and strength provided by the cable sheath. For example, one or more layers of metallic (e.g., steel) tape along with one or more dielectric jackets may form the cable sheathing. Metallic or fiberglass reinforcing rods (e.g., GRP) may also be incorporated into the sheath. In addition, aramid, fiberglass, or polyester yarns may be employed under the various sheath materials (e.g., between the cable sheath and the cable core), and/or ripcords may be positioned, for example, within the cable sheath.
Similar to buffer tubes, optical fiber cable sheaths typically have a circular cross section, but cable sheaths alternatively may have an irregular or non-circular shape (e.g., an oval, trapezoidal, or flat cross-section).
By way of example, the present optical fiber may be incorporated into single-fiber drop cables, such as those employed for Multiple Dwelling Unit (MDU) applications. In such deployments, the cable jacketing must exhibit crush resistance, abrasion resistance, puncture resistance, thermal stability, and fire resistance as required by building codes. An exemplary material for such cable jackets is thermally stable, flame-retardant polyurethane (PUR), which mechanically protects the optical fibers yet is sufficiently flexible to facilitate easy MDU installations. Alternatively, a flame-retardant polyolefin or polyvinyl chloride sheath may be used.
In general and as will be known to those having ordinary skill in the art, a strength member is typically in the form of a rod or braided/helically wound wires or fibers, though other configurations will be within the knowledge of those having ordinary skill in the art.
Optical fiber cables containing optical fibers as disclosed may be variously deployed, including as drop cables, distribution cables, feeder cables, trunk cables, and stub cables, each of which may have varying operational requirements (e.g., temperature range, crush resistance, UV resistance, and minimum bend radius).
Such optical fiber cables may be installed within ducts, microducts, plenums, or risers. By way of example, an optical fiber cable may be installed in an existing duct or microduct by pulling or blowing (e.g., using compressed air). An exemplary cable installation method is disclosed in commonly assigned U.S. Pat. No. 7,574,095 for a Communication Cable Assembly and Installation Method, (Lock et al.), and U.S. Patent Application Publication No. US2008/0317410 for a Modified Pre-Ferrulized Communication Cable Assembly and Installation Method, (Griffioen et al.), each of which is incorporated by reference in its entirety.
As noted, buffer tubes containing optical fibers (e.g., loose or ribbonized fibers) may be stranded (e.g., around a central strength member). In such configurations, an optical fiber cable's protective outer sheath may have a textured outer surface that periodically varies lengthwise along the cable in a manner that replicates the stranded shape of the underlying buffer tubes. The textured profile of the protective outer sheath can improve the blowing performance of the optical fiber cable. The textured surface reduces the contact surface between the cable and the duct or microduct and increases the friction between the blowing medium (e.g., air) and the cable. The protective outer sheath may be made of a low coefficient-of-friction material, which can facilitate blown installation. Moreover, the protective outer sheath can be provided with a lubricant to further facilitate blown installation.
In general, to achieve satisfactory long-distance blowing performance (e.g., between about 3,000 to 5,000 feet or more), the outer cable diameter of an optical fiber cable should be no more than about 70 to 80 percent of the duct's or microduct's inner diameter.
Compressed air may also be used to install optical fibers in an air blown fiber system. In an air blown fiber system, a network of unfilled cables or microducts is installed prior to the installation of optical fibers. Optical fibers may subsequently be blown into the installed cables as necessary to support the network's varying requirements.
Moreover, the optical fiber cables may be directly buried in the ground or, as an aerial cable, suspended from a pole or pylon. An aerial cable may be self-supporting, or secured or lashed to a support (e.g., messenger wire or another cable). Exemplary aerial fiber optic cables include overhead ground wires (OPGW), all-dielectric self-supporting cables (ADSS), all dielectric lash cables (AD-Lash), and figure-eight cables, each of which is well understood by those having ordinary skill in the art. (Figure-eight cables and other designs can be directly buried or installed into ducts, and may optionally include a toning element, such as a metallic wire, so that they can be found with a metal detector.
In addition, although the optical fibers may be further protected by an outer cable sheath, the optical fiber itself may be further reinforced so that the optical fiber may be included within a breakout cable, which allows for the individual routing of individual optical fibers.
To effectively employ the present optical fibers in a transmission system, connections are required at various points in the network. Optical fiber connections are typically made by fusion splicing, mechanical splicing, or mechanical connectors.
The mating ends of connectors can be installed to the fiber ends either in the field (e.g., at the network location) or in a factory prior to installation into the network. The ends of the connectors are mated in the field in order to connect the fibers together or connect the fibers to the passive or active components. For example, certain optical fiber cable assemblies (e.g., furcation assemblies) can separate and convey individual optical fibers from a multiple optical fiber cable to connectors in a protective manner.
The deployment of such optical fiber cables may include supplemental equipment, which itself may employ the present optical fiber as previously disclosed. For instance, an amplifier may be included to improve optical signals. Dispersion compensating modules may be installed to reduce the effects of chromatic dispersion and polarization mode dispersion. Splice boxes, pedestals, and distribution frames, which may be protected by an enclosure, may likewise be included. Additional elements include, for example, remote terminal switches, optical network units, optical splitters, and central office switches.
A cable containing the present optical fibers may be deployed for use in a communication system (e.g., networking or telecommunications). A communication system may include fiber optic cable architecture such as fiber-to-the-node (FTTN), fiber-to-the-telecommunications enclosure (FTTE), fiber-to-the-curb (FTTC), fiber-to-the-building (FTTB), and fiber-to-the-home (FTTH), as well as long-haul or metro architecture. Moreover, an optical module or a storage box that includes a housing may receive a wound portion of the optical fiber disclosed herein. By way of example, the optical fiber may be wound with a bending radius of less than about 15 millimeters (e.g., 10 millimeters or less, such as about 5 millimeters) in the optical module or the storage box.
Moreover, present optical fibers may be used in other applications, including, without limitation, fiber optic sensors or illumination applications (e.g., lighting).
The present optical fibers may include Fiber Bragg Grating (FBG). As will be known by those having ordinary skill in the art, FBG is a periodic or aperiodic variation in the refractive index of an optical fiber core and/or cladding. This variation in the refractive index results in a range of wavelengths (e.g., a narrow range) being reflected rather than transmitted, with maximum reflectivity occurring at the Bragg wavelength.
Fiber Bragg Grating is commonly written into an optical fiber by exposing the optical fiber to an intense source of ultraviolet light (e.g., a UV laser). In this respect, UV photons may have enough energy to break molecular bonds within an optical fiber, which alters the structure of the fiber, thereby increasing the fiber's refractive index. Moreover, dopants (e.g., boron or germanium) and/or hydrogen loading can be employed to increase photosensitivity.
In order to expose a coated glass fiber to UV light for the creation of FBG, the coating may be removed. Alternatively, coatings that are transparent at the particular UV wavelengths (e.g., the UV wavelengths emitted by a UV laser to write FBG) may be employed to render coating removal unnecessary. In addition, silicone, polyimide, acrylate, or PFCB coatings, for instance, may be employed for high-temperature applications.
A particular FBG pattern may be created by employing (i) a photomask placed between the UV light source and the optical fiber, (ii) interference between multiple UV light beams, which interfere with each other in accordance with the desired FBG pattern (e.g., a uniform, chirped, or titled pattern), or (iii) a narrow UV light beam for creating individual variations. The FBG structure may have, for example, a uniform positive-only index change, a Gaussian-apodized index change, a raised-cosine-apodized index change, or a discrete phase shift index change. Multiple FBG patterns may be combined on a single optical fiber.
Optical fibers having FBG may be employed in various sensing applications (e.g., for detecting vibration, temperature, pressure, moisture, or movement). In this respect, changes in the optical fiber (e.g., a change in temperature) result in a shift in the Bragg wavelength, which is measured by a sensor. FBG may be used to identify a particular optical fiber (e.g., if the fiber is broken into pieces).
Fiber Bragg Grating may also be used in various active or passive communication components (e.g., wavelength-selective filters, multiplexers, demultiplexers, Mach-Zehnder interferometers, distributed Bragg reflector lasers, pump/laser stabilizers, and supervisory channels).
This application further incorporates entirely by reference the following commonly assigned patents, patent application publications, and patent applications: U.S. Pat. No. 5,574,816 for Polypropylene-Polyethylene Copolymer Buffer Tubes for Optical Fiber Cables and Method for Making the Same; U.S. Pat. No. 5,717,805 for Stress Concentrations in an Optical Fiber Ribbon to Facilitate Separation of Ribbon Matrix Material; U.S. Pat. No. 5,761,362 for Polypropylene-Polyethylene Copolymer Buffer Tubes for Optical Fiber Cables and Method for Making the Same; U.S. Pat. No. 5,911,023 for Polyolefin Materials Suitable for Optical Fiber Cable Components; U.S. Pat. No. 5,982,968 for Stress Concentrations in an Optical Fiber Ribbon to Facilitate Separation of Ribbon Matrix Material; U.S. Pat. No. 6,035,087 for an Optical Unit for Fiber Optic Cables; U.S. Pat. No. 6,066,397 for Polypropylene Filler Rods for Optical Fiber Communications Cables; U.S. Pat. No. 6,175,677 for an Optical Fiber Multi-Ribbon and Method for Making the Same; U.S. Pat. No. 6,085,009 for Water Blocking Gels Compatible with Polyolefin Optical Fiber Cable Buffer Tubes and Cables Made Therewith; U.S. Pat. No. 6,215,931 for Flexible Thermoplastic Polyolefin Elastomers for Buffering Transmission Elements in a Telecommunications Cable; U.S. Pat. No. 6,134,363 for a Method for Accessing Optical Fibers in the Midspan Region of an Optical Fiber Cable; U.S. Pat. No. 6,381,390 for a Color-Coded Optical Fiber Ribbon and Die for Making the Same; U.S. Pat. No. 6,181,857 for a Method for Accessing Optical Fibers Contained in a Sheath; U.S. Pat. No. 6,314,224 for a Thick-Walled Cable Jacket with Non-Circular Cavity Cross Section; U.S. Pat. No. 6,334,016 for an Optical Fiber Ribbon Matrix Material Having Optimal Handling Characteristics; U.S. Pat. No. 6,321,012 for an Optical Fiber Having Water Swellable Material for Identifying Grouping of Fiber Groups; U.S. Pat. No. 6,321,014 for a Method for Manufacturing Optical Fiber Ribbon; U.S. Pat. No. 6,210,802 for Polypropylene Filler Rods for Optical Fiber Communications Cables; U.S. Pat. No. 6,493,491 for an Optical Drop Cable for Aerial Installation; U.S. Pat. No. 7,346,244 for a Coated Central Strength Member for Fiber Optic Cables with Reduced Shrinkage; U.S. Pat. No. 6,658,184 for a Protective Skin for Optical Fibers; U.S. Pat. No. 6,603,908 for a Buffer Tube that Results in Easy Access to and Low Attenuation of Fibers Disposed Within Buffer Tube; U.S. Pat. No. 7,045,010 for an Applicator for High-Speed Gel Buffering of Flextube Optical Fiber Bundles; U.S. Pat. No. 6,749,446 for an Optical Fiber Cable with Cushion Members Protecting Optical Fiber Ribbon Stack; U.S. Pat. No. 6,922,515 for a Method and Apparatus to Reduce Variation of Excess Fiber Length in Buffer Tubes of Fiber Optic Cables; U.S. Pat. No. 6,618,538 for a Method and Apparatus to Reduce Variation of Excess Fiber Length in Buffer Tubes of Fiber Optic Cables; U.S. Pat. No. 7,322,122 for a Method and Apparatus for Curing a Fiber Having at Least Two Fiber Coating Curing Stages; U.S. Pat. No. 6,912,347 for an Optimized Fiber Optic Cable Suitable for Microduct Blown Installation; U.S. Pat. No. 6,941,049 for a Fiber Optic Cable Having No Rigid Strength Members and a Reduced Coefficient of Thermal Expansion; U.S. Pat. No. 7,162,128 for Use of Buffer Tube Coupling Coil to Prevent Fiber Retraction; U.S. Pat. No. 7,515,795 for a Water-Swellable Tape, Adhesive-Backed for Coupling When Used Inside a Buffer Tube (Overton et al.); U.S. Patent Application Publication No. 2008/0292262 for a Grease-Free Buffer Optical Fiber Buffer Tube Construction Utilizing a Water-Swellable, Texturized Yarn (Overton et al.); European Patent Application Publication No. 1,921,478 A1, for a Telecommunication Optical Fiber Cable (Tatat et al.); U.S. Pat. No. 7,570,852 for an Optical Fiber Cable Suited for Blown Installation or Pushing Installation in Microducts of Small Diameter (Nothofer et al.); U.S. Patent Application Publication No. US 2008/0037942 A1 for an Optical Fiber Telecommunications Cable (Tatat); U.S. Pat. No. 7,599,589 for a Gel-Free Buffer Tube with Adhesively Coupled Optical Element (Overton et al.); U.S. Pat. No. 7,567,739 for a Fiber Optic Cable Having a Water-Swellable Element (Overton); U.S. Patent Application Publication No. US2009/0041414 A1 for a Method for Accessing Optical Fibers within a Telecommunication Cable (Lavenne et al.); U.S. Patent Application Publication No. US2009/0003781 A1 for an Optical Fiber Cable Having a Deformable Coupling Element (Parris et al.); U.S. Patent Application Publication No. US2009/0003779 A1 for an Optical Fiber Cable Having Raised Coupling Supports (Parris); U.S. Patent Application Publication No. US2009/0003785 A1 for a Coupling Composition for Optical Fiber Cables (Parris et al.); U.S. Patent Application Publication No. US2009/0214167 A1 for a Buffer Tube with Hollow Channels, (Lookadoo et al.); U.S. patent application Ser. No. 12/466,965 for an Optical Fiber Telecommunication Cable, filed May 15, 2009, (Tatat); U.S. patent application Ser. No. 12/506,533 for a Buffer Tube with Adhesively Coupled Optical Fibers and/or Water-Swellable Element, filed Jul. 21, 2009, (Overton et al.); U.S. patent application Ser. No. 12/557,055 for an Optical Fiber Cable Assembly, filed Sep. 10, 2009, (Barker et al.); U.S. patent application Ser. No. 12/557,086 for a High-Fiber-Density Optical Fiber Cable, filed Sep. 10, 2009, (Lovie et al.); U.S. patent application Ser. No. 12/558,390 for a Buffer Tubes for Mid-Span Storage, filed Sep. 11, 2009, (Barker); U.S. Patent Application No. 61/112,845 for Single-Fiber Drop Cables for MDU Deployments, filed Nov. 10, 2008, (Overton); U.S. Patent Application No. 61/112,863 for Bend-Insensitive-Fiber Loose Tube Cables, filed Nov. 10, 2008, (Overton); U.S. Patent Application No. 61/112,912 for a Reduced-Size Flat Drop Cable with Bend-Insensitive Fiber, filed Nov. 10, 2008, (Overton); U.S. Patent Application No. 61/112,926 for ADSS Cables with Bend-Insensitive Fiber, filed Nov. 10, 2008, (Overton); U.S. Patent Application No. 61/112,965 for Reduced-Diameter Ribbon Cables with High-Performance Optical Fiber, filed Nov. 10, 2008, (Overton); U.S. Patent Application No. 61/113,067 for a Reduced-Diameter, Easy-Access Loose Tube Cable, filed Nov. 10, 2008, (Overton).
In the specification and/or figures, typical embodiments of the invention have been disclosed. The present invention is not limited to such exemplary embodiments. The figures are schematic representations and so are not necessarily drawn to scale. Unless otherwise noted, specific terms have been used in a generic and descriptive sense and not for purposes of limitation.
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Disclosed is a reduced-diameter optical fiber that employs a novel coating system. When combined with a bend-insensitive glass fiber, the novel coating system according to the present invention yields an optical fiber having exceptionally low losses. The coating system features (i) a softer primary coating with excellent low-temperature characteristics to protect against microbending in any environment and in the toughest physical situations and, optionally, (ii) a colored secondary coating possessing enhanced color strength and vividness. The secondary coating provides improved ribbon characteristics for structures that are robust, yet easily entered (i.e., separated and stripped). The optional dual coating is specifically balanced for superior heat stripping in fiber ribbons, with virtually no residue left behind on the glass. This facilitates fast splicing and terminations. The improved coating system provides optical fibers that offer significant advantages for deployment in most, if not all, fiber-to-the-premises (FTTx) systems.
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FIELD OF THE INVENTION
[0001] The present invention relates to glazing component connectors, glazing components connected by such connectors, structures incorporating such components, methods of connection of glazing components and methods of constructing structures incorporating such components.
BACKGROUND TO THE INVENTION
[0002] The present invention is particularly, though not exclusively, concerned with conservatory structures and their assembly.
[0003] In the construction of conservatory structures, a variety of connectors is required for various components within the structure. Such connections need to be quick, simple, robust and suitable for the wide variety of conservatory configurations provided in the modern market. Additionally, for the connection of a number of components, some angular flexibility is required. For instance, when a glazing bar is connected to a hip, the angle of their connection can vary between conservatory designs. Accordingly, a connector for connecting such components needs to provide the necessary amount of angular variation. Typically, the connection angle variation of up to about 40° is required.
[0004] Preferred embodiments of to the present invention aim to obviate or overcome a disadvantage of the prior art, whether such disadvantage or prior art is referred to herein or otherwise.
SUMMARY OF THE INVENTION
[0005] According to the present invention in a first aspect, there is provided a glazing component connector comprising a first part and a second part, the first part comprising a head for reception by a complementary channel, from which head extends a shank for enabling connection to another glazing component, and a locking clip for locating about the head thereby to secure the first part to the channel.
[0006] Suitably, the locking clip is generally C-shaped. Suitably, the ends of the C-shaped clip comprise diverging feet.
[0007] Suitably, the locking clip comprises at least one hole therethrough. Suitably, the hole is suitable for receiving a grub screw for securing the first part in position. Suitably, the hole is opposite the open part of the C-shaped clip. Suitably, the clip comprises three holes therethrough. Suitably, the locking clip comprises a shaped part to receive the shank of the first part.
[0008] Suitably, the locking clip comprises a guide tab extending therefrom.
[0009] Suitably, the head comprises a truncated ball.
[0010] Suitably, the shank comprises an external thread
[0011] According to the present invention in a second aspect, there is provided a first glazing component comprising a channel, a glazing component connector according to the first aspect of the present invention, wherein the head s fits within the channel and the locking clip fits between the outside of the head and the inside of the channel, and a second a glazing component connected to the first glazing component by the first part of the glazing component connector.
[0012] Suitably, the channel is a longitudinal channel.
[0013] Effectively, the locking clip increases the diameter of the head whereby the head can no longer be removed from the channel through the longitudinal opening therein formed by the channel. Thus, the head of the first part can be inserted into the channel through the longitudinal opening therein and the locking clip can be slid over the head axially.
[0014] Suitably, the channel is generally C-shaped.
[0015] Suitably, the first glazing component comprises a component selected from one of an eaves beam, a hip rafter, wall plate and a valley.
[0016] Suitably, the angle of the first glazing component relative to the second glazing component can be varied by pivotal movement of the connector.
[0017] According to the present invention in a third aspect, there is provided a structure comprising a first glazing component connected to a second glazing component in a manner according to the second aspect of the present invention.
[0018] Suitably, the structure comprises a conservatory s structure.
[0019] According to the present invention in a fourth aspect, there is provided a method of connection of a first glazing component to a second a glazing component, the first glazing component comprising a channel, the method comprising the steps of providing a glazing component connector according to the first aspect of the present invention, inserting one of the first part and the second part into the channel of the first glazing component, inserting the other of the first part and the second part into the channel of the first glazing component and connecting the second the glazing component to the first glazing component using the shank of the first part.
[0020] Suitably, the first part is inserted into the channel before the second part. Suitably, the channel comprises a longitudinal opening therein, and the first part is inserted into the longitudinal opening of the channel. Suitably, the locking clip is moved axially over the first part.
[0021] Alternatively, the channel comprises a longitudinal opening therein, and the locking clip is inserted into the longitudinal opening of the channel. Suitably, the first part is inserted axially into the channel inside the glazing clip.
[0022] According to the present invention in a fifth aspect, there is provided a method of constructing a structure, which method comprises connecting a first glazing component to a second glazing component according to the fourth aspect of the present invention.
[0023] Suitably, the structure is a conservatory structure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The present invention will now be described, by way of example only, with reference to the drawings that follow; in which:
[0025] FIG. 1 is an end elevation of a glazing component connector according to the present invention in a first glazing component.
[0026] FIG. 2 is an exploded view of FIG. 1 .
[0027] FIG. 3 is an end elevation showing the first part of the glazing component connector being inserted into the first glazing component.
[0028] FIG. 4 is an end elevation showing the second part of the glazing component connector being inserted into the first glazing component.
[0029] FIG. 5 is a functional flow diagram of a method according to the present invention.
[0030] FIG. 6 is a plan of the view of a first embodiment of a glazing component connector second part.
[0031] FIG. 7 is a cross-sectional end view of the part shown in FIG. 6 .
[0032] FIG. 8 is a plan view of a second embodiment of a glazing component connector second part.
[0033] FIG. 9 is a plan view of a third embodiment of a glazing component connector second part.
[0034] FIG. 10 is a schematic perspective elevation of a conservatory structure incorporating glazing components connected according to the present invention.
[0035] FIG. 11 is an enlarged cross-sectional end view of the glazing component connector of FIG. 1 showing the range of angles it can adopt.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0036] Referring to FIG. 1 of the drawings that follow, there is shown a glazing component connector 10 comprising a first part 12 and a second part 14 , which glazing component connector 10 is located in a C-shaped channel 16 of a first glazing component 18 , in this case an eaves beam.
[0037] Referring additionally to FIG. 2 of the drawings that follow, the first part 12 comprises a head 20 and a shank 22 . The head 20 consists of a truncated sphere, and from which extends the shank 22 which has a threaded portion 24 . First part 12 is formed from a steel casting or the like.
[0038] Second part 14 is a locking clip which comprises an elongate member, generally C-shaped in cross section, from the open part of which C-shape extend two diverging feet 26 . Approximately centrally located in the C-shaped part of the locking clip 14 are three holes 28 , 30 , 32 (see FIGS. 6-10 ). A tab 33 is provided at one end of the locking clip 14 . The locking clip 14 is pressed from sprung steel.
[0039] First glazing component 18 can be a generally standard component except that it provides the C-shaped channel 16 extending from end-to-end for approximately 270°. Channel 16 has open ends 34 . First glazing component 18 is a plastics extrusion. Channel 16 extends longitudinally along the length of first glazing component of 18 and the open ends 34 form a longitudinal opening in the C-shaped channel 16 .
[0040] As can be seen from FIGS. 3 and 4 of the drawings that follow, the head 20 of first part 12 can pass into channel 16 of the first glazing component 18 through the open ends 34 of channel 16 . Similarly, locking clip 14 can also pass into channel 16 of the first glazing component 18 through the open ends 34 of channel 16 . In the case of locking clip 14 , its normal diameter is greater than the spacing between the open ends 34 , but it can be squeezed by using feet 26 to fit in channel 16 .
[0041] In this embodiment, the external diameter of head 20 is approximately 0.5 mm smaller than the internal diameter of the C-shaped channel 16 and the glazing clip thickness is just less than 0.5 mm.
[0042] Referring to FIG. 5 of the drawings that follow, a method of use of the glazing component connector 10 will now be described.
[0043] In step 100 the first glazing component 18 having a C-shaped channel 16 is provided. In step 102 a glazing component connector 10 is provided. In step 104 head 20 of first part 12 is inserted into C-shaped channel 16 through the longitudinal opening therein. Tab 33 can aid the insertion of the head 20 , acting as a guide. In step 106 the locking clip 14 is slid axially into the gap between the outside of head 20 and the inside of the C-shaped channel 16 . In practice the position desired for the glazing component connector 10 may be spaced significantly from either end of the glazing component 18 , in which case (or otherwise) both the first and second parts 12 , 14 can be inserted into the longitudinal gap of C-shaped channel 16 , and then the glazing clip 14 can be slid axially (relative to the longitudinal axis of the C-shaped channel 16 ) over the head 20 of first part 12 .
[0044] In an alternative step 106 , instead the locking clip 14 can be inserted into C-shaped channel 16 first and then the head 20 of first past 12 can be slid axially into glazing clip 14 .
[0045] In step. 108 , the shank 22 of first part 12 is located at the desired angle and a grub screw 36 ( FIG. 11 ) is inserted through the base of C-shaped channel 16 to engage with a flat 38 ( FIG. 2 ) of head 20 . FIG. 11 of the drawings that follow illustrates the range of angles the first part 12 can adopt in the C-shaped channel 16 , over a range of 41°. Thus, the angle of the first glazing component relative to the second glazing component can be varied by pivotal movement of the connector. The centre of rotation of the pivoting action is within head 20 .
[0046] In step 110 a second glazing component 40 , such as in this case a hip rafter, is connected to first glazing component 18 using the shank 22 of first part 12 typically this will involve passing the shank to 22 into a hole in the second glazing component 40 and using a nut (not shown) to secure the second glazing component 40 in place. Alternatively, first part 12 is bolted to second glazing component 40 before being connected to first glazing component. Instead of a nut, the shank can tap into a port.
[0047] FIGS. 6-9 show various embodiments of locking clip 14 . In the embodiment of FIGS. 8 and 9 , the glazing clip 14 does not include the diverging feet 26 . However the edge of the C-shaped includes a shaped portion 42 for receiving a part of the shank 22 , helping to locate the shank 22 in place and stop it from moving unhelpfully when the second glazing component 40 is being located.
[0048] Referring to FIG. 9 of the drawings that follow, there is shown a third embodiment of a glazing clip 14 , the end view of which is similar to FIG. 9 .
[0049] Referring to FIG. 10 of the drawings that follow, there is shown a conservatory structure 100 comprising a plurality of glazing components connected using the glazing component connector described herein.
[0050] Thus, preferred embodiments of the present invention provide a glazing component connector that is simple to use, reliable and robust yet flexible in its applications.
[0051] Although described hearing a relation to the connection of an eaves beam to another glazing component, the glazing component connector 10 is not limited to eaves beams and can be used for, for instance, hips, valleys and wall plates.
[0052] Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.
[0053] All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.
[0054] Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.
[0055] The invention is not restricted to the details of the foregoing embodiment (s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.
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There is disclosed a glazing component connector ( 10 ) comprising a first part ( 12 ) and a second part ( 14 ), the first part ( 12 ) comprising a head ( 20 ) for reception by a complementary channel ( 16 ), from which head extends a shank ( 22 ) for enabling connection to another glazing component, and a locking clip ( 14 ) for locating about the head thereby to secure the first part ( 12 ) to the channel ( 16 ).
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FIELD OF THE INVENTION
The present invention relates to agricultural equipment and particularly to a field vehicle for compacting crop material within a large plastic storage bag.
BACKGROUND OF THE INVENTION
Storage of field crops, traditionally provided by structures such as silos and barns, can now be accomplished by large plastic storage bags. The bags, when filled with crop, extend typically up to twelve feet in diameter and up to 250 feet in length. A loading apparatus receives the field crop and controllably compacts the crop into the storage bag as the bag is deployed upon the ground behind the apparatus. The loading apparatus is equipped with an output feed rotor and the plastic storage bag is folded upon the loading apparatus with its open end exposed to the rotor to receive the crop material. The crop material is fed to the rotor and the rotor compacts the material in the bag as the bag is controllably deployed behind the loading apparatus. Thus, as the bag fills and unfolds from the loading apparatus, the apparatus moves away from the stationary portion of the bag lying on the ground.
A loading apparatus of this general type is described in U.S. Pat. No. 4,337,805 titled AGRICULTURAL BAG LOADING APPARATUS, issued Jul. 6, 1982 to Johnson et al., and assigned to the assignee of the present invention. The entire disclosure of U.S. Pat. No. 4,337,805 is incorporated herein by reference.
Forward propulsion for the loading apparatus results from the compacting force applied to the crop material within the bag. A stop positioned behind the bag and coupled to the loading apparatus by cables prevents rearward sliding of the bag. The cables wrap around drums on the loading apparatus and a brake mechanism of the drums resistively releases in response to pressure created as the rotor compresses the crop material. In other words, the loading apparatus is pushed forward by force feeding the crop material into the bag and against the stop. Thus, controlled crop compaction as well as forward propulsion is accomplished by resistively braking against forward movement resulting from loading of the storage bag.
The loading apparatus must be suitably positioned for each bagging operation. For example, to lay a storage bag along the edge of a field the loading apparatus must be first positioned along the field edge and pointed in a direction following the edge. If a second bag is to be laid down, the loading apparatus must be suitably repositioned within the field. Heretofore, such field repositioning between bagging operations has required manual wheel positioning, e.g., by crowbar, and coupling to a towing vehicle. Also, the loading apparatus must be movable between bagging sites, i.e., from field to field, typically along roadways. Such a loading apparatus typically cannot travel on roadways in its operational direction of travel due to its inordinate breadth. Accordingly, such a loading apparatus desirably travels also in a direction along its longitudinal axis, i.e., in a direction orthogonal to its operational direction of travel, for towing.
It has been suggested, in the above-noted U.S. Pat. No. 4,337,805, that the wheels of such a loading apparatus rotate through a steering angle of 90° whereby the loading apparatus may be moved for transport as well as for field positioning use. As noted above, such wheel manipulation has been provided only by manual means such as by crowbar use and such field positioning has been provided by towing the loading apparatus.
Given the basic structure and operation of such a loading apparatus, it may be appreciated that operational steering control, field positioning between bagging operations, and transportation between bagging sites along roadways, can be difficult. Generally, the direction of operational travel, i.e., during a bagging operation, has been largely uncontrolled resulting in meandering storage bag placement. Selective braking for steering, i.e. braking one side more than the other, has been attempted, but such braking complicates the crop compaction process because braking is used to control crop compaction within the storage bag.
Accordingly, it is desirable that a crop loading apparatus be capable of properly collecting field crop by controlled crop compaction within the storage bag, and be capable of traveling conveniently in both an operational direction and in a transport direction with steering functions independent of braking functions in both traveling directions.
SUMMARY OF THE INVENTION
In accordance with the present invention, an elongate agricultural crop loading vehicle includes a power assisted steering mechanism operable from an operator station providing a sufficiently broad range of steering for travel in mutually orthogonal directions, one an operational direction transverse to the elongate axis of the vehicle and the other a transport direction along the elongate axis of the vehicle. During operation, the vehicle compacts crop into a storage bag lying on the ground behind the vehicle with forward propulsion resulting from compacting pressure. During transport or field repositioning, propulsion is a accomplished by motors applying rotational force to the wheels. The operator can quickly switch steering modes between operational and transport, as well as enable crab steering.
The vehicle, given its broad range of steering and field positioning capabilities, is well suited for efficient crop storage and for transport between storage sites.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an agricultural field vehicle according to the present invention.
FIG. 2 is a view, as if taken along lines 2--2 at FIG. 1, of a steering mechanism of the vehicle of FIG. 1 but with the wheels turned 90 degrees relative to that shown in FIG. 1.
FIG. 3 is a top view of the steering mechanism of FIG. 2.
FIG. 4 is a top schematic view of the field vehicle of FIG. 1 in a field positioning configuration.
FIG. 5 is a top schematic view similar to FIG. 4, but showing the field vehicle in an operational configuration.
FIGS. 6--7 illustrate several of the variety of steering capabilities of the field vehicle of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 illustrates an agricultural crop collection field vehicle 10. In the illustrated embodiment, vehicle 10 is adapted for collecting silage 12 and compacting silage 12 into storage bag 14, shown in phantom in FIG. 1. Crop loading is provided by bag 14 being folded over output tunnel 16 to receive from rotor 18 the silage 12. Silage 12 is deposited upon conveyor table 19 for delivery to rotor 18. Stop 20 captures the closed end of bag 14 and couples by way of cables 21 to vehicle 10. Cables 21 controllably extend by resistive braking of cable drums 23 to control relative movement between the stationary closed end of bag 14 and vehicle 10. As rotor 18 compacts silage 12 into bag 14, vehicle 10 is urged in the forward direction 22 due to such compaction force. Drums 23 are braked against movement of vehicle 10 in the forward direction 22. By controllably braking against the compaction force and allowing cables 21 to resistively extend, vehicle 10 moves in the forward direction 22 just as the compaction force exceeds the braking force applied to drums 23. In this manner, a desired level of silage 12 compaction, i.e., material density, within bag 14 as well as forward propulsion of vehicle 10 is achieved.
Vehicle 10 is generally elongate with a wheel support including wheel sets 30 and 32 providing steering therefor. With reference to FIGS. 2 and 3, each wheel set 30 and 32 comprises four wheels, a front wheel pair 34, individually 34a and 34b, sharing a common axis of rotation 36 and a rear wheel pair 38, individually 38a and 38b, sharing a common axis of rotation 40. It will be understood that the wheel set 32 is of similar arrangement and operation to that shown for wheel set 30 in FIGS. 2 and 3. It may be noted that the orientation of wheel sets 30 and 32 in FIG. 1 is orthogonal relative to the orientation shown for wheel sets 30 and 32 in FIGS. 2 and 3. As will be discussed more fully below, vehicle 10 is capable of travel in mutually orthogonal directions.
Front wheel pair 34 and a rear wheel pair 36 each rotatably mount upon a corresponding one of vertical steering shafts 42 and 44, respectively. Shafts 42 and 44 rotatably mount to frame 46 of vehicle 10, as indicated at bearing mounts 48, for rotation about corresponding vertical axes of rotation 50 and 52, respectively. Shafts 42 and 44 are held by bearing mounts 48 against vertical movement relative to frame 46. Shafts 42 and 44 lie orthogonal to the corresponding one of wheel axes of rotation 36 and 40, respectively, Wheel pairs 34 and 38 thereby support vehicle 10 by way of shafts 42 and 44 and by way of frame 46.
Vehicle 10 steering is provided by suitably rotating shafts 42 and 44 about the vertical axes of rotation 50 and 52, respectively. More particularly, by simultaneously rotating shafts 42 and 44 while maintaining a parallel relation between wheel axes of rotation 36 and 40, wheel pairs 34 and 38 steer in a common direction. To accomplish coordinated rotation of shafts 42 and 44, each shaft 42 and 44 includes a lever arm 60 fixedly attached thereto and extending radially outward therefrom. A push rod 62 rotatably couples, at the pins 64, the distal ends of lever arms 60. Push rod 62 is of proper length to maintain lever arms 60 in parallel relation. Thus, a parallelogram is defined by the lever arms 60 at first opposite ends and by the frame 46 and push rod 62 at second opposite ends. A hydraulic cylinder 70 couples to frame 46 by way of pin 72 at its cylinder end and couples to push rod 62 by way of pin 74 at its rod end. Actuating hydraulic cylinder 70 causes coordinated rotation of shafts 42 and 44 to provide coordinated steering of the wheel pairs of wheel set 30.
Wheel set 30 has an unusually wide steering range 76 including mutually orthogonal directions of travel, one direction being along the longitudinal axis 80, shown orthogonal to frame 46 in FIG. 3, of vehicle 10 and the other being the above-noted forward direction 22 along the transverse axis 82, shown parallel to the frame 46 in FIGS. 2 and 3, of vehicle 10. In the illustrated embodiment, lever arms 60 and the throw of hydraulic cylinder 70 are of sufficient length to move shafts 42 and 44 through 128 degrees of rotation to define the steering range 76.
The line of travel 84 for wheel set 30 is, as illustrated in FIG. 3, in alignment for movement along the axis 80. Retraction of hydraulic cylinder 70 moves wheel pairs 34 and 38 clockwise, as seen in FIG. 3, by as much as 28 degrees to bring the line of travel 84 to a first steering extreme 86. Extension of hydraulic cylinder 70, relative to that shown in FIG. 3, moves wheel pairs 34 and 38 through as much as 100 degrees of counter-clockwise rotation, as seen in FIG. 3, to place line of travel 84 at the other steering extreme 88 of steering range 76. Accordingly, when positioned for travel along axis 80, vehicle 10 may be steered by at least 28 degrees in either direction and when positioned for travel along the axis 82 vehicle 10 may be steered by at least 10 degrees in either direction.
A hydraulic motor 90 rotationally drives the wheel pair 38 for propelling vehicle 10. Motor 90 is bi-directional for forward and reverse rotation of wheel pair 38. As will be more fully discussed below, motor 90 is generally used for field positioning of vehicle 10 in preparation for a bagging operation.
FIG. 4 is a top schematic view of the field vehicle 10 in a field positioning configuration, i.e., prior to a bagging operation. In FIG. 4, bag 14 is mounted to output tunnel 16 and ready to receive silage from rotor 10. As portrayed, however, bag 14 has not yet been deployed upon the ground. Boom 92 (shown in perspective in FIG. 1) of vehicle 10 supports bag 14 at the mouth of output tunnel 16. In such configuration, vehicle 10 may be suitably positioned in preparation for a bagging operation.
FIG. 4 shows details of the other wheel set 32 as well as a hydraulic power circuit for operation of vehicle 10. Reference numerals earlier applied to the elements of wheel set 30 are similarly applied to the wheel set 32. Wheel set 32 includes a motor in the form of a hydraulic cylinder 70 used to move all wheels of wheel set 32 through a steering range 76 similar to that shown for the wheel set 30. Wheel set 32 also includes a hydraulic motor 90 coupled for rotationally driving the corresponding wheel pair 38 in forward and reverse rotational directions about the corresponding axis 40.
Accordingly, it will be appreciated that by coordinated actuation of hydraulic cylinders 70, a desired direction of travel 84 for wheel sets 30 and 32 is achieved. For example, to maintain parallel the axes of rotation 36 and 40 of wheel set 30 with the axes of rotation 36 and 40 of wheel set 32, hydraulic cylinders 70 would extend in unison and retract in unison by similar amounts. Also, by retracting one cylinder 70 and extending the other cylinder 70, counter clockwise movement of one of wheel sets 30 and 32 results while clockwise rotation of the other one of wheel sets 30 and 32 results.
Field vehicle 10 includes a diesel power plant 100 which drives a hydraulic pump 102. Pump 102 couples by way of hydraulic lines 104 to an operator station 106 to thereby provide the controls for operator steering. Operator station 106 includes various lever controls and gauges for manipulation of the hydraulic system. Each motor 90 couples to operator station 106 by way of corresponding hydraulic lines 108. Each hydraulic cylinder 70 also couples by way of corresponding hydraulic lines 110 to operator station 106. Hydraulic lines 112 couple respective ones of cable drums 23 for controlled braking of drum 23 rotation. Rotor 18 is driven by a hydraulic rotor motor 114 which in turn receives power from operator station 106 by way of hydraulic lines 116. Table 19 comprises a conveyor belt 118 actuated by table motor 120 which in turn is driven from operator station 106 by way of hydraulic lines 122.
It will, therefore, be understood that a person positioned at operator station 106 has control over the various devices of vehicle 10. More particularly, the operator may independently control each hydraulic cylinder 70 in order to independently determine the steering direction of each wheel set 30 and 32 as well as control each motor 90 for propelling vehicle 10 in a desired direction.
With reference to FIG. 5, once the operator positions vehicle 10 in alignment for a bagging operation, bag 14 is released from boom 92 for deployment upon the ground. Table 19 then brings silage 12 deposited on conveyor 118 against the rotor 18. Rotor 18 is actuated by operation of rotor motor 114 and the silage 12 is delivered by way of output tunnel 16 to bag 14 for compaction therein. The operator controllably brakes the drums 23 in order to control deployment of bag 14 behind vehicle 10 as well as movement of vehicle 10 in the forward direction 22.
Wheel sets 30 and 32 are oriented, by way of hydraulic cylinder 70 actuation, for travel along the forward direction 22. Such forward motion, it is noted, results from the operation of rotor 18 compacting silage 12 within bag 14 and the yieldably resistant braking action of drums 23, cables 21, and stop 20. As vehicle lo moves in the forward direction 22, control over the steering of vehicle 10, and therefore the overall deployment of bag 14, is provided by operation of hydraulic cylinders 70. More particularly, by coordinated operation of cylinders 70, vehicle 10 is provided with crab steering during bagging operations for highly controlled positioning of vehicle 10. In this manner, deployment of bag 14 may be along a desired path, typically a straight line.
FIG. 6 illustrates a field positioning steering mode for vehicle 10 wherein wheel set 32 is oriented for travel along the longitudinal axis 80 and wheel set 30 is steered by operation of the corresponding hydraulic cylinder 70. In this mode of travel, forward and reverse propulsion is available by operation of hydraulic motors 90. The operator may also move (not shown) the wheel set 32, in the opposite rotational direction as that illustrated for the wheel set 30, in order to provide very tight turning radius for vehicle 10.
FIG. 7 illustrates a crab mode field positioning of vehicle 10. In FIG. 7, hydraulic cylinders 70 are actuated in unison, i.e., each extending and retracting in unison, such that the axes of rotation 36 and 40 of wheel sets 30 and 32 remain parallel whereby crab steering in forward and reverse directions within the steering range 76 is available if needed for field positioning.
As will be appreciated by those skilled in the art, given the bi-directional ability of motors 90 and the independent steering control of wheel sets 30 and 32 through 128 degrees of steering, vehicle 10 is well adapted for agile field positioning in preparation for bagging operations. The steering configurations shown in FIGS. 6 and 7 are only examples of the wide variety of vehicle 10 steering capabilities.
Thus, an improved steering and propulsion mechanism for a field crop loading vehicle has been shown and described. The field vehicle 10 may be provided with operational propulsion in the direction 22, along the transverse axis 82, by way of the compaction of silage 12 within bag 14. The second propulsion mechanism includes the motors 90 coupled to wheels set 30 and 32. The second propulsion mechanism includes both forward and reverse directions. The steering mechanisms of wheel sets 30 and 32 provide a broad range of steering capability whereby, in combination with the dual propulsion mechanisms provided by vehicle 10, efficient crop collection and storage within bag 14 is provided. The vehicle 10, having such broad range of steering capabilities and dual propulsion mechanisms, is well adapted for controlled deployment of bag 14 as well as convenient and rapid field positioning between each bagging operation.
It will be appreciated that the present invention is not restricted to the particular embodiment shown herein and that variations may be made thereon without departing from the scope of the invention as found in the appended claims and equivalents thereof.
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A field crop collection vehicle provides improved crop collection and storage. The vehicle steers through mutually orthogonal directions of travel and includes forward and reverse propulsion for accurate, quick and convenient field positioning in preparation for a bagging operation. During bagging, the vehicle is propelled by compaction force developed by placement of crop material with the storage bag and is steerable to more controllably place the storage bag upon the ground.
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BACKGROUND OF THE INVENTION
The present invention relates generally to drill bits, and more specifically relates to drill bits and methods for their construction which include an improved cutter configuration adapted to optimize the formation/cutter contact area while providing a desired volume of formation cutting material.
The use of drill bits for the drilling of wells in earth formations, or for taking cores of formations, is well known. Bits for either purpose may include either stationary cutting elements for cutting or abrading the earth formation, or cutting elements mounted on rotating cones. Bits as presently known to the industry which utilize stationary cutting elements typically use either natural or synthetic diamonds as cutting elements and are known as "diamond bits". References herein to "diamond bits" or "diamond drill bits" refer to all bits, for either drilling or coring, having primarily stationary cutters.
Conventional diamond drill bits include a solid body having a plurality of cutting elements, or "cutters," secured thereto. As the bit is rotated in the formation, the cutters contact and cut the formation. A flow of fluid is maintained through the bit to cool the cutters and to flush formation cuttings away from the cutters and into the annulus surrounding the drill string.
Conventional diamond drill bits may have a variety of different types of cutting surfaces, such as, for example, polycrystalline diamond compact (PDC) cutters, thermally stable diamond product (TSP) cutters, and mosaic-type cutters. Mosaic cutters are typically formed of a plurality of geometrically-shaped thermally stable diamond elements cooperatively arranged and retained in a desired shape, to form a unitary cutter.
With conventional diamond drill bits having such discrete cutters, the cutters are distributed on the bit to provide a desired volume of diamond for cutting the formation. The diamond volume will be determined partially in response to the amount of diamond which will provide adequate cutting of the formation, taking into consideration the wear of the cutters as the formation is cut. Additionally, as is well known, the cutters proximate the outer portion of the bit radius wear much more quickly because of the greater surface velocity as they encounter the formation. Accordingly, outer portions of the bit require much more diamond volume than do inner portions.
Conventional diamond drill bits having discrete cutters include individual cutters distributed across the face of the bit to establish the desired diamond volume. The cutters are distributed in greater numbers along outer portions of the bit radius, to provide greater diamond volume in such areas. Such conventional designs have inherent limitations, however. For example, the volume of diamond, and therefore the number of cutters, required to provide acceptable performance from the bit in terms of wear life, may require an undesirably high weight on bit to cause the bit to penetrate the formation. This is because a large number o cutters providing the diamond volume will also provide a large surface area in contact with the formation which resists penetration of the bit. Additionally, conventional bits, and particularly those with circular cutters, have surface contact areas which increase as the bit wears. For example, when an initial group of five one inch diameter cutters are initially contacting the formation, their curvilinear downward portions will only contact the formation across a chord (contact area), determined by the depth of cut, i.e., the depth to which each of the five cutters actually penetrates the formation. However, when these exemplary five cutters are half worn, their contact area is five full diameters of the cutters. With conventional bits, therefore, as the bit wears, the required weight on bit typically increases, while the rate of penetration typically decreases.
Bits have been proposed for use which have included cutting surfaces with increased depth toward the outer portions of the bit. However, these designs have achieved this increased depth through adjacent squares and rectangles of cutter facing, built up in steps forming large "fins" extending in stair-step blocks away from the body, forming a squared "fishtail" shape. An example of such a prior art bit is found in U.S. Pat. No. 3,059,708 issued Oct. 23, 1962, to Cannon et al. Such proposed designs have not been suitable for the use of different types of cutter facings. Additionally, the design produces a bit having a deep cone stepped profile, in clear contrast to favored generally flat or parabolic bit profiles. Such generally flat bits will be described herein as among those bits having "generally parabolic profiles." Thus, such "generally parabolic profiles," as used herein, may include bits having a generally flat, or slightly downwardly sloping (i.e., shallow-cone shaped) lower surface, as well as bits having upwardly sloping contours, such as, for example, generally "bullet-shaped" bits.
Accordingly, the present invention provides a new drill bit and method for constructing a drill bit wherein the total diamond volume may be varied independently of the diamond volume contacting the earth formation at a given time. Additionally, the diamond volume may be distributed along the radius of the bit to provide an optimal diamond volume at each point along the bit radius.
SUMMARY OF THE INVENTION
Drill bits may be constructed in accordance with the present invention which include a body member with cutter blades which have a generally parabolic bottom profile. The cutter blades will be constructed with a cutter face, preferably formed of diamond, which increases in vertical dimension generally as a function of increased distance from the centerline of the bit. In a particularly preferred embodiment, the cutting face will include a generally gradual flat or parabolic form, and the height of the cutting face will increase generally continually in response to increased distance from the centerline of the bit. The cutting face of the cutting blade may be formed of any desired type of diamond material, such as a PDC layer, a TSP layer, a composite mosaic surface, or an impregnated matrix filled with either PDC, TSP or natural diamond segments.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts an exemplary embodiment of a drill bit in accordance with the present invention, illustrated from a perspective view.
FIG. 2 depicts the drill bit of FIG. 1 from a lower plan view.
FIG. 3 schematically depicts a cutting blade of the drill bit of FIG. 1.
FIG. 4 depicts a cutting blade of the drill bit of FIG. 1 in perspective view.
FIG. 5 depicts the cutting blade of FIG. 4 illustrated from a side view and in vertical section.
FIG. 6 depicts an alternative embodiment of a cutter blade in accordance with the present invention.
FIG. 7 depicts an alternative embodiment of a cutter blade in accordance with the present invention.
FIG. 8 depicts an alternative embodiment of a cutter blade in accordance with the present invention.
FIG. 9 depicts an alternative configuration of a cutter blade suitable for use with drill bits in accordance with the present invention.
FIG. 10 depicts a drill bit adapted for coring a formation, in accordance with the present invention, illustrated from a bottom plan view.
FIG. 11 schematically depicts a cutting blade of the drill bit of FIG. 10.
FIG. 12 schematically depicts a cutter blade of the drill bit of FIG. 10 illustrated from a perspective view.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now to FIGS. 1-5, therein is depicted an exemplary embodiment of a drill bit 10 in accordance with the present invention. Drill bit 10 includes a body section 12 which includes cutting sections, indicated generally at 14, and gage pads, indicated generally at 16. Cutting sections 14 are each "blades" which may be formed from various diamond materials, as will be described in more detail later herein. Each of these blades 14 forms a single "cutter" of drill bit 10. Gage pads 16 may serve a cutting function, but normally would not unless extending radially beyond those portions of cutter blades 14 extending to the gage of drill bit 10.
Body 12 is preferably at least partially a molded component fabricated through conventional metal infiltration technology. Body 12 will preferably be formed of a tungsten carbide matrix. Body 12 is coupled to a shank 18 which includes a threaded portion adapted to couple to a drill string. Shank 18 and body 12 are preferably formed to be functionally integral with one another. Additionally, in this preferred embodiment, body 12 includes a steel form 20 coupled to shank 18, which generally follows the contours of body 12 proximate cutter 14. Drill bit 10 also includes an internal recess (not illustrated), through which hydraulic flow will pass.
In the depicted embodiment of drill bit 10, each cutter 14 extends from proximate the center line 24 of bit 10 to gage 26 of bit 10. Each cutter blade 14 is a mosaic cutter formed of a plurality of triangular-cross sectioned, thermally stable diamond product (TSP) elements bonded into the tungsten carbide matrix. Preferably, each TSP element will be coated to facilitate bonding of the material to the metal matrix of drill bit 10. An exemplary method and apparatus for coating TSP elements 28 is described in copending application Ser. No. 095,054, filed Sept. 15, 1987, in the names of Sung and Chen. The specification of application Ser. No. 095,054 is incorporated herein by reference for all purposes.
As can be seen from FIG. 3, each cutter blade 14 includes an initially generally flat profile across the surface of bit 10, indicated generally at 30. As can also be seen from FIG. 3, the vertical dimension, or height, of cutter blade 14 varies across the width of blade 14. Cutter blade 14 does not extend inwardly to centerline 24 of bit 10. A small core may be cut by blade 14 which will be broken by a core ejector during drilling. Because of anticipated increased wear proximate this core, the height of cutter blade 14 is increased at the innermost dimension 34 of blade 14, relative to an adjacent outer radial portion 35 of cutter blade 14. Similarly, with the exception of inner area establishing height 34, the height of cutter blade 14 generally increases in response to increased distance from centerline 24 of bit 10. The height 36 of cutter blade 14 proximate gage 26 of bit 10 is approximately 200% that of the shortest portions 35 of cutter blade 14.
The vertical dimension of cutter blade 14 is established in relation to the anticipated wear at each location along the bit radius 38. Cutter blade 14 is preferably formed of a single layer of TSP elements. Cutter blade 14 therefore has a generally uniform depth (or thickness), of approximately 0.106 inches (the nominal dimension of each TSP element 28), throughout its height.
As can be seen from a review of FIGS. 1-5, as bit 10 is rotated within a formation, even as wear to cutter blade 14 occurs, the volume of diamond per unit of length along bit radius 36 will remain generally constant. The only increase with respect to the volume of diamond contacting the formation which will occur is due to wear proximate primarily the outer half of the radius of bit 10 which establishes a radius on cutter blade 14, thereby effectively increasing the total length of cutter blade 14 between its innermost dimension and gage 26. The increasing of the vertical dimension of cutter blades 14 in an uphole direction facilitates both improved hydraulic cleaning of the cutter blades and improved flushing of the cuttings up the hole.
In FIG. 5, therein is depicted cutter blade 14 in vertical section. Steel form 20, discussed earlier herein, provides one means for optimizing the operation of drill bit 10. As noted earlier herein, steel form 20 preferably includes extensions 40 which extend into the matrix forming the rearward portion 42 of each blade, and which, in fact, form a substantial inner volume of such rearward portions. As bit 10 is operated in a formation, cutter blades 14 will gradually be worn down. The matrix forming the body of bit 10 is extremely hard and resistant to abrasion. If cutter blades 14 include solely a matrix backing behind the diamond cutting face, then as cutter blades 14 wear, the matrix may begin to form a standoff relative to the formation. However, where form 20 provides extensions 40 which form a substantial volume of the backup portions of each cutter blade 14, as each blade wears, the steel backing will gradually be exposed and will form an increasingly larger area of each exposed cutter blade backing. Because of the steel's relative abradability relative to the diamond (and to the matrix), the exposed steel backing provides only minimal resistance to the passage of each cutter blade 14 into the formation.
Referring now to FIG. 6, therein is depicted an alternative embodiment of a cutter blade 50 suitable for use with the present invention. Cutter blade 50, instead of being formed of a plurality of TSP segments of triangular cross-section, is formed of a plurality of generally cylindrical segments 52. Cylindrical segments 52 may be polycrystalline diamond compact (PDC) cutters, or may be cylindrical TSP segments. Cylindrical segments 52 will preferably be arranged as shown, in offset rows or horizons, in cutter blade 50, to provide maximum uniformity of diamond surface area at all horizons within cutter blade 50. Alternatively, different size cylinders may be arranged to form cutting blade 14. For example, large cylindrical segments as depicted could be arranged in aligned rows, with smaller cylindrical segments placed at intermediate horizons, in "voids" established between the larger cylindrical segments.
Referring now to FIG. 7, therein is depicted another alternative embodiment of a cutter blade 60 suitable for use with the present invention. Cutter blade 60 includes a plurality of cylindrical or partially cylindrical elements 62 which are cooperatively conformed and arranged to provide a generally uniform diamond volume per unit of surface length across cutter blade 60. Segments 62 are conformed with "scallops", where needed, to provide interlocking to cooperatively form cutter blade 60. Alternatively, segments 62 may include flats to facilitate their placement proximate one another. Such segments could then make use of used diamond cutters, which will often have flats worn in them naturally.
Referring now to FIG. 8, therein is depicted an alternative embodiment of a cutter blade 70 formed of PDC layers. Cutter blade 70 may be formed of one or more of such layers, depending upon the size of the cutter blade and the available PDC layers. In the depicted embodiment, cutter blade 70 is formed of three PDC layers 72a, 72b, 73c, with each layer being partially rectangular, but with one angled surface increasing the total height of each layer 72a, 72b, 72c.
Many configurations of cutter blades may be utilized in accordance with the present invention. A particular advantage of the present invention is that the blades may be conformed to provide optimal diamond distributions in various conformities of generally parabolic profile cutter blades. Referring now also to FIG. 9, therein is depicted an alternative embodiment of a cutter blade 80 believed to be generally representative of an embodiment having particular utility with the present invention. Cutter blade 80 has a generally parabolic profile with a height which increases generally continually from an inward portion of the blade to a gage cutting portion of the blade. The conformity may be considered as being defined by an upper surface 82 having a first general radius adapted to extend from the inner dimension to a point short of gage dimension 84, and by having a lower surface 86 of a radius smaller than the inner radius, but laterally displaced sufficiently to allow cooperative conforming of blade 80 with upper surface 82. As can be seen from FIG. 9, the height of cutter blade 80 reaches a maximum vertical dimension proximate gage dimension 84.
The depicted embodiment of cutter blade 80 is formed of an abrasive matrix material, but may be of any suitable diamond cutting material, such as, for example, those described and illustrated with respect to FIGS. 1-8. Preferably, the abrasive matrix material will be a diamond abrasive. Such a diamond abrasive matrix may be formed by placing diamond pieces in an abradable matrix. The matrix can be formed of the same tungsten carbide matrix used to form the body 12 of bit 10.
Referring now to FIGS. 10-12, therein is depicted a drill bit adapted for cutting cores (i.e., a "coring bit") 90, in accordance with the present invention. Coring bit 90 preferably includes four cutting blades 92 spaced at ninety degree intervals around body member 94 of bit 90. In the depicted embodiment, each cutting blade 92 is again a mosaic blade formed of a plurality of TSP segments 96. Cutting blades 92 again increase in height from a generally inner dimension 98, to exterior gage 100 of bit 90. As can be seen in FIG. 11, the increase in height is incremental across cutter blades 92. Additionally, the outer portion of each blade is above the inner portions (each figure depicts each bit in an inverted position, for clarity), providing an uphole slope on each cutter blade, facilitating improved hydraulic flow and removal of cuttings.
As with bit 10 of FIGS. 1-5, coring bit 90 again preferably includes a body 102 fabricated through metal matrix infiltration technology, and preferably includes a steel form member, partially illustrated at 104, which provides an extension behind each blade 92.
Many modifications and variations may be made in the techniques and structures and illustrated herein without departing from the spirit and scope of the present invention. For example, cutter blades may be formed of virtually any variety of geometric segments, including square and other shapes not particularly described or illustrated herein. Accordingly, it should be readily understood that the embodiments described and illustrated herein are illustrative only and are not to be considered as limitations upon the scope of the present invention.
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The subject drill bits include a body member with cutter blades having a generally parabolic bottom profile. The cutter blades each include a diamond cutting face which increases in vertical height generally as a function of increased distance from the center line of the bit. The increased height allows the bits to provide a desired total diamond cutting volume at each radius of the bit, while allowing the diamond contact area to remain generally constant as the bit wears.
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FIELD OF THE INVENTION
[0001] The present invention is related to a method and a device for safeguarding a digital process device, and more particularly to safeguard the personal computer (PC) by way of the safeguard key in the memory card. Therefore when the PC is powered on, a digital certification and BIOS(Basic Input Output System) update may be executed in order to promote the PC safety.
BACKGROUND OF THE INVENTION
[0002] The utility of the computer is well-known. It can process many important programs, documents or data. Therefore, once the computer is broken, the damage will follow. Unfortunately, an unpredictable accident can always happen, and above all, the damage from a computer virus is the most serious and the most unpreventable. The methods that viruses invade the computer are various. The anti-virus software may defense many viruses, but the new viruses overcoming the anti-virus are produced quickly. Therefore, how to reduce the loss caused by a virus is an important topic.
[0003] A new virus is able to invade computer BIOS(Basic Input Output System). The BIOS virus damaging to the computer system and obstructing the computer operation will cause a large loss. Therefore, it is necessary to reduce the loss when this accident happens.
[0004] The original method to resolve this kind of accident is to replace the damaged BIOS ROM with a new BIOS ROM(Read Only Memory) or to write a new BIOS into the EPROM (Erasable Program ROM), but his method is not convenient. Another method is to design a backup BIOS on the motherboard. When the main BIOS is invaded by a virus, the system can switch to the backup BIOS to start the computer, but it is obvious that this method will increase the cost of a motherboard.
SUMMARY OF THE INVENTION
[0005] An object of the present invention is to provide a new method for improving the mentioned weak points by way of using a memory stick or a storage card.
[0006] Another object of the present invention is to provide a new method for starting the computer by way of a storage card after the computer is invaded by a virus.
[0007] Another object of the present invention is to provide a new method for updating the BIOS of the motherboard by way of writing the correct version of BIOS into the EPROM when the computer is invaded by a virus but started by the storage card.
[0008] According to the present invention, a method for safeguarding a digital process device having a data storage slot, the method comprising steps of: providing a drawable storage device for storing a start-up code of the digital process device; and processing the starting code for executing a start-up operation of the digital process device when the drawable storage device insert into the data storage slot of the digital process device.
[0009] In accordance with one aspect of the present invention, the digital process device is a computer, and the data storage slot is a slot of a memory card.
[0010] In accordance with one aspect of the present invention, the drawable storage device is a storage card.
[0011] In accordance with one aspect of the present invention, the start-up code includes a password of the digital process device, the digital process device use the password to execute the start-up operation in order to proceed a digital certification operation.
[0012] In accordance with one aspect of the present invention, the start-up code includes a correct version of BIOS for starting up the digital process device.
[0013] In accordance with one aspect of the present invention, the start-up code includes a new version BIOS for updating an old version BIOS of the digital process device.
[0014] In accordance with one aspect of the present invention, before processing the start-up code, detect a BIOS of the digital process device, and depending on a damage of the BIOS, using the drawable storage device to start up the digital process device.
[0015] In accordance with one aspect of the present invention, a recovery operation is executed after the start-up operation.
[0016] According to the present invention, a device for safeguarding a digital process device comprising: a storage device independent from the digital process device, the storage device having a start-up code of the digital process device; and an interface electrically connected to the digital process device and being able to receive the storage device, the digital process device executing a start-up operation through the interface.
[0017] In accordance with one aspect of the present invention, the storage device has a drawable storage device and a data storage slot, and the data storage slot is a slot of the drawable storage device.
[0018] In accordance with one aspect of the present invention, the drawable storage device is a storage card.
[0019] In accordance with one aspect of the present invention, the digital process device is a computer.
[0020] In accordance with one aspect of the present invention, the start-up code includes a password of the digital process device, the digital process device use the password to execute the start-up operation in order to proceed a digital certification operation.
[0021] In accordance with one aspect of the present invention, the start-up code includes a correct version of BIOS for starting up the digital process device.
[0022] In accordance with one aspect of the present invention, the start-up code includes a new version BIOS for updating an old version BIOS of the digital process device.
[0023] In accordance with one aspect of the present invention, when the digital process device processes the start-up code, a BIOS of the digital process device is detected previously, and depending on a damage of the BIOS, the drawable storage device is used to start up the digital process device.
[0024] In accordance with one aspect of the present invention, a recovery operation is executed after the start-up operation.
[0025] The present invention may best be understood through the following description with reference to the accompanying drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] [0026]FIG. 1 is a flowchart for recovering the BIOS (Basic Input Output System) with the memory card according to the present invention;
[0027] [0027]FIG. 2 is a flowchart for digital certification with the memory card according to the present invention; and
[0028] [0028]FIG. 3 is a block diagram according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0029] Please refer to FIG. 1 showing flowchart for recovering the BIOS with the memory card( or storage card). The steps are as follows:
[0030] S 11 : Begin. The computer is powered on.
[0031] S 12 : After the computer is powered up, the program counter of the CPU (Central Process Unit) will point to the starting address of the BIOS. Then the the BIOS will be responsible for starting up the computer.
[0032] S 13 : Check the BIOS. If the BIOS are damaged, a hardware method can be used to make the program counter of the CPU pointing to the address of the memory card. The memory card is of one type of ROM (Read Only Memory). It stores the correct version BIOS. Therefore, when the program counter points to the exact address of the memory card, the BIOS stored in the memory card will be executed and the the computer will be started up.
[0033] S 14 : If the BIOS is not damaged, the computer will be started up normally. On the other hand, if the computer is started up with the memory card, the BIOS will be recovered after the computer are started. That is, the correct version BIOS stored in the memory card will be written to the flash ROM in the computer system, so next time the computer will be started up by itself.
[0034] [0034]FIG. 2 is a flowchart for digital certification with the memory card according to the present invention. The steps are as follows:
[0035] S 21 : Begin.
[0036] S 22 : Check whether the memory is inserted on the memory card slot.
[0037] S 23 : Generally, the personal data is stored in the memory card. The computer can certificate the user through the personal data. But, for the sake of security, a password may set into the memory card. Therefore, if the password is ignored, then jump to step S 25 .
[0038] S 24 : If the password is necessary, then check the password.
[0039] S 25 : If the password is correct, then start up the computer with the BIOS.
[0040] S 26 : If the password is wrong, then stop computer.
[0041] [0041]FIG. 3 is the block diagram according to the present invention. The chipset 35 , the BIOS ROM 34 , the memory card interface 33 , the control unit 32 , the memory card 31 and the memory card slot 30 are included. This hardware stucture is based on a computer. Therefore, the BIOS update, the BIOS recovery, the digital certification or the memory card start-up may be worked.
[0042] The memory card 31 is a drawable memory card. It can be drawn from the memory card slot 30 or insert into the memory card slot 30 . The start-up code is stored in the memory card. The start-up code includes the password data and correct version BIOS (or new version BIOS). Whe the memory card 31 are inserted into the memory card slot 30 , the system may process the start-up code for executing the start-up operation of the computer.
[0043] Due to the start-up code stored in the drawable memory card, the system on the start-up operation can address to the memory card and access the start-up code. When the BIOS on mother board is damaged, the BIOS wrong signal and memory card 31 inserting signal will enable the control unit 32 to drop down the CS# signal. If the CS# signal is dropped down, the BIOS ROM 34 will be inactive, so the BIOS in the memory card will execute the start-up operation of the computer. Certainly, the control unit 32 can be implemented by an AND gate.
[0044] For the application, the memory card may be a storage card, the memory card slot may be a storage card slot, and the the computer may be a digital process device.
[0045] The memory card having a password may execute the digital certification when the computer is powered on. The correct version BIOS stored in the memory card may be used to start up the digital process device. Certainly, the new version BIOS stored in the memory card may be used to update the old BIOS in the mother board. The system BIOS may be checked before the start-up operation. If the system BIOS is damaged, the BIOS in the drawable memory device may be used to start up the computer. The correct version BIOS in the memory card may be written into the BIOS ROM, after the computer is started up, if the system BIOS is damaged. The correct version BIOS or the new version BIOS is included in the start-up code.
[0046] Speaking of the technique detail, the storage card such as memory stick and memory card is used to start up the computer by detecting the BIOS damage or the check sum error at the start-up precedure. If the BIOS is damaged, a writing process to the flash memory can be proceeded, after the program in the storage card is read to the system RAM. If the ROM chip is broken completely, the storage card may replace it to start up the computer system. On the other hand, the storage card to start up the computer may be attain the object of protable BIOS and computer security&privacy.
[0047] The advantages of the present invention are as follows:
[0048] 1. The digital certification is implemented.
[0049] 2. The BIOS recovery or update with the start-up code in the memory card may safeguard the computer against the virus accidents.
[0050] 3. The memory card can be used to start up the computer, so the BIOS is protable, and the security or privacy of the computer will be improved.
[0051] While the invention has been described in terms of what are presently considered to be the most practical and preferred embodiments, it is to be understood that the invention need not be limited to the disclosed embodiment. On the contrary, it is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims which are to be accorded with the broadest interpretation so as to encompass all such modifications and similar structures.
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A method is proposed for safeguarding a digital process device having a data storage slot. The method comprises steps of: providing a drawable storage device for storing a start-up code of the digital process device; and processing the starting code for executing a start-up operation of the digital process device when the drawable storage device insert into the data storage slot of the digital process device.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an electronic controller including an electronic circuit board, which is provided with a connector at its end, and is housed in a case.
2. Description of the Related Art
An electronic controller used for controlling a vehicle or the like generally has the following structure. The electronic controller includes electronic components such as an input/output circuit, a communication circuit, a microcomputer, and a power supply circuit. The electronic components are provided on a printed circuit board which is an electronic circuit board. At the same time, a connector for connection to an external device is provided to the printed circuit board. Then, the printed circuit board is housed in a case.
As the above-mentioned type of electronic controller, the following electronic controller is known. The electronic controller uses a base and a cover which are vertically separated from each other. A printed circuit board, onto which connectors are mounted, is interposed between the base and the cover. Then, contact surfaces of the base, the cover, and the connectors are bonded with a water-proof sealing material (for example, see Japanese Patent Application Laid-open No. 2003-258454).
In the electronic controller having the configuration described above, however, the connectors are brought into contact with the base and the cover. Therefore, the connectors are required to be formed into a shape, for example, which can be brought into contact with the base and the cover. Therefore, there is a problem in that a general-purpose connector cannot be used as the connector for the electronic controller described above.
The shapes of the base and the cover may be changed according to the shape of the connector to cope with the above-mentioned problem. In this case, however, there is another problem in that the base and the cover are required to be set for each connector.
SUMMARY OF THE INVENTION
The present invention has been made to solve the problems described above, and has an object to provide an electronic controller which allows the use of a general-purpose connector and does not require the setting of a case for housing an electronic circuit board therein for respective connectors each having a different shape so as to enable a reduction in cost.
An electronic controller according to the present invention includes: an electronic circuit board onto which an electronic component is mounted; a connector provided at an end of the electronic circuit board; a case housing the electronic circuit board therein and including an opening portion on a side of the connector; and a connector retaining member provided between the connector and an inner wall surface of the opening portion so as to be held in close contact with the inner wall surface and to surround the connector.
The electronic controller according to the present invention includes the connector retaining member provided between the connector and the inner wall surface of the opening portion of the case so as to be held in close contact with the inner wall surface and to surround the connector. By changing the connector retaining member according to the shape of the connector, the case having the same shape can be generally used regardless of the shape of the connector. Thus, the cost of the case can be reduced by production volume effects.
Further, the outer shape of the connector itself is not required to be designed according to the shape of the case, and therefore an inexpensive general-purpose connector can be used. As a result, the cost can be further reduced.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings:
FIG. 1 is a perspective view illustrating an electronic controller according to Embodiment 1 of the present invention;
FIG. 2 is an exploded partial sectional view of the electronic controller illustrated in FIG. 1 ;
FIG. 3A is a view illustrating the relation between a connector and a connector retaining member in FIG. 1 , FIG. 3B and FIG. 3C are respectively other example views illustrating the relation between a connector and a connector retaining member;
FIGS. 4A to 4C are views illustrating an assembly procedure simultaneously sealing with a filling material a interfaces between the connector and the connector retaining member and a interface between the connector retaining member and a case in the electronic controller of FIG. 1 ;
FIG. 5 is an exploded perspective view of an electronic controller according to Embodiment 2 of the present invention;
FIG. 6 is an exploded partial sectional view of an electronic controller according to Embodiment 3 of the present invention;
FIG. 7A is a front view illustrating a principal part of an electronic controller according to Embodiment 4 of the present invention, FIG. 7B is a partial side sectional view of FIG. 7A ; and
FIG. 8 is a view illustrating a mode simultaneously sealing with a filling material a interfaces between the connector and the connector retaining member in FIG. 7 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinafter, an electronic controller according to each of embodiments of the present invention is described based on the accompanying drawings. In each of the drawings, the same or equivalent members and components are denoted by the same reference numerals for description.
Embodiment 1
FIG. 1 is a perspective view illustrating an electronic controller 1 according to Embodiment 1 of the present invention, and FIG. 2 is an exploded partial sectional view of the electronic controller 1 illustrated in FIG. 1 .
The electronic controller 1 mounted in an engine provided in an engine room includes an electronic circuit board 2 housed in a case 6 . Electronic components 16 are mounted onto the electronic circuit board 2 . The electronic circuit board 2 is electrically connected to terminals 3 a of connectors 3 at an end. The connectors 3 are electrically connected to another input/output device (not shown).
The connectors 3 are mounted to an opening portion 6 a of the case 6 through an intermediation of a connector retaining member 4 . In an inner wall surface of the case 6 , a groove portion 7 which is open toward the opening portion 6 a is formed over the entire circumference.
The shape of the connector retaining member 4 corresponds to that of the opening portion 6 a . A sealing material 8 is applied to the groove portion 7 . A distal end portion 4 a of the connector retaining member 4 is inserted into the groove portion 7 to be fitted into the opening portion 6 a of the case 6 . The interior of the connector retaining member 4 is filled with a filling material 5 made of, for example, a polyurethane resin. The filling material 5 prevents water from entering through interfaces A between the connectors 3 and the connector retaining member 4 .
As illustrated in FIG. 3A , the connector retaining member 4 has holes 4 b formed through a bottom surface. The connectors 3 are inserted into the holes 4 b to integrate the connector retaining member 4 with the connectors 3 .
Alternatively, as illustrated in FIG. 3B , a connector retaining member 4 A may be formed of two vertically separate members, that is, a first connector retaining member 4 A- 1 and a second connector retaining member 4 A- 2 . In this manner, the connector retaining members 4 A- 1 and 4 A- 2 are fitted into each other to vertically interpose the connectors 3 therebetween so as to be integrated with the connectors 3 .
Further alternatively, as illustrated in FIG. 3C , a connector retaining member 4 B may be formed by multiple-molding around the connectors 3 to be integrated with the connectors 3 .
Next, an assembly procedure of the electronic controller 1 having the configuration described above is described.
First, the connectors 3 are inserted into the holes 4 b of the connector retaining member 4 to integrate the connector retaining member 4 with the connectors 3 .
Next, the terminals 3 a of the connectors 3 and the electronic circuit board 2 are connected to each other.
Thereafter, the interior of the connector retaining member 4 is filled with the filling material 5 so as to leave the distal end portion 4 a uncovered. Then, the filling material 5 is cured.
Subsequently, the electronic circuit board 2 , to which the connectors 3 are mounted through the connector retaining member 4 , is inserted through the opening portion 6 a of the case 6 including the groove portion 7 , to which the sealing material 8 is previously applied.
As a result, the connector retaining member 4 is fitted to the opening portion 6 a , and the distal end portion 4 a is fitted into the groove portion 7 . Consequently, the connectors 3 are integrated with the case 6 through an intermediation of the connector retaining member 4 to fabricate the electronic controller 1 .
In the case where the filling material 5 filling the interior of the connector retaining member 4 has a small height which does not cover the terminals 3 a of the connectors 3 , each of the connector terminals 3 a , which is supported in a cantilever fashion without being covered with the filling material 5 , may be electrically connected to the electronic circuit board 2 after the interior of the connector retaining member 4 is filled with the filling material 5 and the filling material 5 is cured.
The electronic controller 1 according to this embodiment includes the connector retaining member 4 which is provided between the connectors 3 and the inner wall surface of the opening portion 6 a and is held in close contact with the inner wall surface so as to close the opening portion 6 a in cooperation with the connectors 3 . Therefore, by changing the connector retaining member 4 according to the shapes of the connectors 3 , the case 6 having the same shape can be generally used regardless of the shapes of the connectors 3 . Thus, the cost of the case can be reduced by production volume effects.
Moreover, the outer shapes of the connectors 3 themselves are not required to be designed according to the shape of the case 6 . Therefore, an inexpensive general-purpose connector can be used as each of the connectors 3 . Accordingly, the cost can be further reduced.
Further, although the filling material 5 fills the interior of the connector retaining member 4 so as to seal the interfaces A between the connectors 3 and the connector retaining member 4 , the filling material 5 does not fill the entire interior of the case 6 .
Therefore, a filling amount of the filling material 5 can be reduced to reduce a weight of the electronic controller 1 . In addition, when the electronic controller 1 is to be discarded, the electronic controller 1 can be easily disassembled, which can reduce an environmental load.
Moreover, the connector retaining member 4 has a bottomed cylindrical shape, which has the holes 4 b formed through the bottom surface. By inserting the connectors 3 into the holes 4 b , the connector retaining member 4 and the connectors 3 can be easily integrated with each other.
Further, the interfaces A between end surfaces of the holes 4 b of the connector retaining member 4 and the circumferential surfaces of the connectors 3 are sealed with the filling material 5 . Therefore, water can be prevented from entering the interior of the case 6 through the interfaces A.
The interfaces A between the connectors 3 and the connector retaining member 4 B, which are connected to each other by multiple-molding, are also sealed with the filling material 5 . Therefore, even in this case, water can be prevented from entering the interior of the case 6 through the interfaces A.
Moreover, an interface B between an outer circumferential surface of the connector retaining member 4 and the inner wall surface of the case 6 is sealed by the groove portion 7 , the sealing material 8 , and the distal end portion 4 a , which constitute sealing means. Therefore, water can be prevented from entering the interior of the case 6 through the interface B.
As described above, in the electronic controller 1 which is mounted to the engine and exposed to water, water can be more reliably prevented from entering the interior of the case 6 by sealing the interfaces A of the connector retaining member 4 with the filling material 5 and sealing the interface B of the connector retaining member 4 with the sealing means.
The groove portion 7 not only corresponds to one of the constituent elements of the sealing means but also serves as a positioning member for the connector retaining member 4 with respect to the case 6 .
The above-mentioned electronic controller 1 can also be fabricated by a procedure illustrated in FIGS. 4A to 4C .
First, the filling material 5 is injected into the case 6 with the opening portion 6 a being oriented upward ( FIG. 4A ).
Next, the electronic circuit board 2 , to which the connectors 3 and the connector retaining member 4 are mounted, is inserted into the case 6 ( FIG. 4B ). Thereafter, the electronic controller 1 is rotated at 180 degrees ( FIG. 4C ). Then, the filling material 5 is cured. As a result, the electronic controller 1 , in which the connectors 3 are integrated with the case 6 through an intermediation of the connector retaining member 4 , is fabricated.
In the case where the fabrication method is used, the sealing material 8 is not required to be previously applied to the groove portion 7 . Therefore, an application step is not needed. In addition, the interfaces A between the connectors 3 and the connector retaining member 4 and the interface B between the connector retaining member 4 and the case 6 are simultaneously sealed with the filling material 5 . Therefore, as compared to the electronic controller 1 illustrated in FIG. 2 , a fabrication time is reduced.
Embodiment 2
FIG. 5 is an exploded perspective view illustrating an electronic controller 1 A according to Embodiment 2 of the present invention.
In the electronic controller 1 A according to Embodiment 2, a case 6 A includes a base 9 and a cover 10 . The base 9 is made of a metal having high heat-radiating effects. The cover 10 houses the electronic circuit board 2 in cooperation with the base 9 . The base 9 , the connector retaining member 4 , and the cover 10 are bonded to each other by an adhesive 15 a . The cover 10 and the connector retaining member 4 are bonded to each other by an adhesive 15 b.
In this embodiment, the adhesive 15 b corresponds to the sealing means of Embodiment 1.
The adhesive 15 b , which is present between the cover 10 and the connector retaining member 4 , is applied to a surface of the connector retaining member 4 . In this case, when the adhesive is to be applied by using an adhesive application machine including a nozzle which is movable only horizontally, the adhesive is not applied to vertical surfaces.
However, the connector retaining member 4 according to this embodiment has a trapezoidal shape having inclined surfaces. Therefore, even when the adhesive application machine is used, the adhesive is applied to the inclined surfaces.
It is apparent that the connector retaining member is required to have the same shape as that of the opening portion 6 a of the case 6 A. However, the shape of the connector retaining member is not limited to the trapezoidal shape. The connector retaining member may have a rectangular shape although the adhesive cannot be applied by using the adhesive application machine.
The remaining configuration is the same as that of the electronic controller 1 according to Embodiment 1.
An adhesive (not shown) is present between the connector retaining member 4 and the opening portion 6 a of the case 6 A. The adhesive is applied to the surface of the connector retaining member 4 . In this case, when the adhesive is applied by using the adhesive application machine including a nozzle which is movable only horizontally, the adhesive is not applied to vertical surfaces.
However, the connector retaining member 4 according to this embodiment has the trapezoidal shape having the inclined surfaces. Therefore, even when the adhesive application machine is used, the adhesive is applied to the inclined surfaces.
It is apparent that the connector retaining member is required to have the same shape as that of the opening portion 6 a of the case 6 A. However, the shape of the connector retaining member is not limited to the trapezoidal shape. The connector retaining member may have a rectangular shape although the adhesive cannot be applied by using the adhesive application machine.
The electronic controller 1 A according to this embodiment is assembled by vertically interposing the electronic circuit board 2 , onto which the connectors 3 are mounted, between the cover 10 and the base 9 , instead of inserting the electronic circuit board 2 , onto which the connectors 3 are mounted, through the opening portion 6 a of the case 6 .
Therefore, even when the case 6 A has such a shape that makes the insertion of the electronic circuit board 2 through the opening portion 6 a of the case 6 A difficult, the electronic controller 1 A can be easily assembled.
Moreover, the base 9 is made of the metal having high heat-radiating effects. Therefore, heat from the electronic components 16 is efficiently radiated to outside through the base 9 .
The other functions and effects are the same as those of the electronic controller 1 according to Embodiment 1.
Embodiment 3
FIG. 6 is an exploded partial sectional view illustrating an electronic controller 1 B according to Embodiment 3 of the present invention.
The electronic controller 1 B according to Embodiment 3 includes a wall portion 17 on one of openings (on the right side of FIG. 6 ) of a connector retaining member 4 C having a cylindrical shape. The filling material 5 to fill the interior of the connector retaining member 4 C is injected from the side of the connectors 3 .
A gap is present between the connectors 3 and the connector retaining member 4 C. The filling material 5 is provided in the gap.
The remaining configuration is the same as that of the electronic controller 1 according to Embodiment 1.
The electronic controller 1 B according to Embodiment 3 can provide the same effects as those of the electronic controller 1 according to Embodiment 1. In addition, the filling material 5 is injected from the side of the connectors 3 and is stopped by the wall portion 17 . Therefore, a distal end portion 4 Ca of the connector retaining member 4 C is ensured to have a predetermined dimension without being affected by the filling material 5 . As a result, the distal end portion 4 Ca can be reliably fitted into the groove portion 7 of the case 6 .
Embodiment 4
FIG. 7A is a front view illustrating a principal part of an electronic controller 1 C according to Embodiment 4 of the present invention, and FIG. 7B is a partial side sectional view of FIG. 7A .
The electronic controller 1 C includes a connector retaining member 4 D having a U-shaped cross section with opposed sides being separated from each other downwardly.
In the case where the connector retaining member 4 having a four-sided frame is to be connected to the connectors 3 by multiple-molding, if distal end potions of the terminals 3 a , which are bent at 90 degrees in the middle, project from the frame of the connector retaining member 4 , the multiple-molding cannot be performed in view of a structure of a molding die.
However, the connector retaining member 4 D does not have a frame portion on the side from which the terminals 3 a project. Therefore, the multiple-molding can be performed.
In the electronic controller 1 C, the connectors 3 are surrounded by the connector retaining member 4 D having a three-sided frame. As illustrated in FIG. 8 , the interfaces A on the three sides between the connectors 3 and the connector retaining member 4 D are sealed by injecting the filling material 5 into the interior of the connector retaining member 4 D under a state in which the connector retaining member 4 D is inclined.
The remaining configuration is the same as that of the electronic controller 1 according to Embodiment 1.
The electronic controller 1 C according to Embodiment 4 can provide the same effects as those of the electronic controller 1 according to Embodiment 1. In addition, even when the distal end portions of the terminals 3 a which are bent at 90 degrees in the middle project from the frame of the connector retaining member 4 D, the multiple-molding can be performed.
Each of the electronic controllers 1 to 1 C according to Embodiments 1 to 4 is mounted to the engine provided in the engine room and is therefore under an environment which is subjected to a sudden change in temperature.
Therefore, if dew condensation or the like occurs inside the case 6 or 6 A, there is a fear in that an electronic circuit of the electronic circuit board 2 is short-circuited by water drops generated by the dew condensation to result in a failure.
In order to cope with the above-mentioned problem, for example, the electronic circuit board 2 may be coated with a coating material such as a silicon resin to provide moisture-proof coating.
The engine provided in the engine room is an example of the location at which each of the electronic controllers 1 to 1 C according to the present invention is mounted. It is apparent that each of the electronic controllers of the present invention can be provided at the location other than in the engine room.
Although the sealing means formed of the groove portion 7 , the sealing material 8 , and the distal end portion 4 a or 4 Ca is described as the sealing means for sealing the interface B between the case 6 and the connector retaining member 4 , 4 C, or 4 D in each of the embodiments described above, it is apparent that the sealing means is not limited thereto. For example, a groove portion may be provided in the case 6 or the connector retaining member 4 , 4 C, or 4 D so that an O-ring is fitted into the groove portion.
Further, although the filling material 5 is used as means for sealing the interfaces A between the connectors 3 and the connector retaining member 4 , 4 C, or 4 D, it is apparent that the means for sealing the interfaces A is not limited thereto. For example, the interfaces A may be sealed by using an adhesive in addition to the use of the filling material.
Further, each of the cases 6 and 6 A of the electronic controllers 1 to 1 C according to Embodiments 1 to 4 described above has a shape which is enlarged on the side of the connectors 3 . However, it is apparent that the present invention is applicable to a case having a uniform height over the entire case.
Further, the shape of each of the connector retaining members 4 , 4 C, and 4 D is not limited to that surrounds the connectors 3 with the four-sided or three-sided frame. The connector retaining member may have a frame with five or more sides to surround the connectors 3 .
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Provided is an electronic controller, which allows the use of a general-purpose connector, and does not require setting of a case for housing an electronic circuit board therein for respective connectors each having a different shape so as to enable a reduction in cost. An electronic controller ( 1 ) includes: an electronic circuit board ( 2 ) onto which an electronic component ( 16 ) is mounted; a connector ( 3 ) provided at an end of the electronic circuit board ( 2 ); a case ( 6 ) housing the electronic circuit board ( 2 ) therein and including an opening portion ( 6 a ) on a side of the connector ( 3 ); and a connector retaining member ( 4 ) provided between the connector ( 3 ) and an inner wall surface of the opening portion ( 6 a ) so as to be held in close contact with the inner wall surface and to surround the connector ( 3 ).
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This is a continuation-in-part of patent application Ser. No. 10/155,760 filed on May 24, 2003.
BACKGROUND OF THE INVENTION
[0002] Barrier coatings and barrier layers are used in a variety of applications; for example absorbent materials, nonwovens, and textiles. They are particularly important in absorbent materials for such products as absorbent pads, medical hygiene products, food bibs, food packaging, table top covers and the like where a hydrophobic layer covers but does not interfere with the absorbent material. The barrier layer prevents the absorbed fluid from penetrating through the side opposite from where fluid was absorbed. When the coatings are used on absorbent pads for food products, it is desirable that they have little or no formaldehyde and no alkylphenol ethoxylate surfactants.
[0003] Absorbent materials are frequently multi-layered in construction and can comprise a liquid-permeable cover sheet having one side designed for placement in contact with the wearer or food, an absorbent section, and an impervious backsheet. Polyethylene films are typically used as a backsheet for absorbent pads because it prevents passage of fluids to the opposite side of the film. In some cases, the polyethylene film is perforated in such a way as to allow water vapor to pass through the film but inhibit the passage of fluids. However, there are drawbacks to the use of polyethylene film for absorbent pads. For example, it is sometimes difficult to place and attach the polyethylene film to a substrate, creating waste when it skews off the substrate during secondary operations. In some cases, application of an adhesive, such as a hot melt adhesive, or some other method of attachment is needed to keep the polyethylene film in place. Also, the polyethylene film needs to be applied in a secondary operation which is separate from the production of the absorbent pad, textile, or nonwoven. A more practical substitute for the polyethylene backsheet would therefore benefit the industry.
[0004] Examples of coatings used as water repellents are disclosed in the following publications:
[0005] Colbert (“Fluorochemicals—fluid repellency for nonwoven substrates” ( TAPPI , September 1976, Vol. 59, No.9, pages 129-131)) discloses the use of fluorochemicals to provide fluid repellency to nonwoven substrates without the formation of continuous film barriers.
[0006] U.S. Pat. No. 4,062,818 (Mate, 1977) discloses an aqueous composition which imparts both flame resistance and water repellency properties to nonwoven textiles. The composition contains a poly(vinyl acetate), a chloro- or bromo-substituted phosphate plasticizer, a polyfluoroalkyl polyacrylate, water repellent, and an inorganic, water soluble salt.
[0007] U.S. Pat. No. 3,912,674 (Stahl, 1975) discloses a water repellent coating made up of an ethylene ionic copolymer, a paraffin wax, and a terpolymer of vinyl acetate, ethylene, and N-methylol acrylamide. The ethylene copolymer dispersion is held in dispersed phase by means of an amine soap surfactant.
[0008] WO98/14078 (Baumann, et al., 1998) discloses a face mask that allows gas to pass through while inhibiting passage of, liquid through it. The mask includes a face-contacting layer, an outer cover layer, a polymeric microfiber mat disposed between the face-contacting layer and the outer cover sheet, and a non-woven fibrous mat disposed between the face-contacting layer and the outer cover sheet. The non-woven fibrous mat includes polymeric fibers and a surface energy reducing agent, such as a fluorochemical, a wax, a silicon or a combination thereof.
[0009] US 2001/0021616 A1 and U.S. Pat. No. 6,251,210 B1 (Bullock et al, 2001) disclose a method of preparing a stain resistant and water repellant textile fabric in which the fabric is first treated with a fluorochemical textile treatment composition and dried at elevated temperature. The treated fabric is then provided with a polymeric film to one side of the treated fabric and dried again at elevated temperature. A detackifying wax may be part of the secondary treatment composition.
BRIEF SUMMARY OF THE INVENTION
[0010] This invention is directed to a coating formulation comprising a blend of a poly(vinyl acetate) emulsion and a paraffin wax emulsion or a vinyl acetate-ethylene (VAE) polymer emulsion and a paraffin wax emulsion. The coating formulation, when applied to a substrate, such as an absorbent or nonwoven material, and dried, has a hydrostatic head barrier sufficient to prevent passage of fluids but allow passage of water vapor through it. The term “fluids” used herein refers to liquids, especially aqueous-based liquids. The coating can be used to replace the backsheet in absorbent products, such as personal hygiene products, medical hygiene products, such as bed pads and nonwoven medical garments, and absorbent pads for food packaging. Other nonwoven products to which the coating can be applied include roofing substrates and housewrap where water barrier properties are required; however passage of water vapor is also required. The coating can also be used in other applications, such as textile fabrics, that require a water barrier to prevent penetration of water or other fluids but allow the escape of water vapor. This invention is also directed to a multi-layer material and a method of making the multi-layer material, wherein the multi-layer material comprises at least one layer of a nonwoven web, an absorbent pad, a textile fabric, or a nonwoven textile, and at least one layer of a blend of a poly(vinyl acetate) emulsion and a paraffin wax emulsion or a VAE polymer emulsion and a paraffin wax emulsion. The blend, after drying, has a hydrostatic head barrier sufficient to prevent passage of fluids through it but allow passage of water vapor. The blend can be applied to one or more of the nonwoven web, absorbent pad, textile fabric, or nonwoven textile that makes up the multi-layer material.
[0011] One embodiment of this invention is a blend comprising a poly(vinyl acetate) emulsion or a VAE polymer emulsion, a paraffin wax emulsion, and, optionally, other components, which, when applied on a substrate and dried, has a hydrostatic head barrier sufficient to prevent passage of fluids through it but allow passage of water vapor.
[0012] Another embodiment of this invention is a blend comprising a poly(vinyl alcohol)-stabilized VAE polymer emulsion and a paraffin wax emulsion which, when applied on a substrate and dried, has a hydrostatic head barrier sufficient to prevent passage of fluids through it but allow passage of water vapor.
[0013] Yet another embodiment of this invention is a multi-layer material comprising:
[0014] (a) at least one layer of a substrate, such as a nonwoven web, an absorbent pad, a textile fabric, or a nonwoven textile; and
[0015] (b) at least one layer of a coating formulation comprising a blend of a poly(vinyl acetate) emulsion and a paraffin wax emulsion or a VAE polymer emulsion and a paraffin wax emulsion;
[0016] said coating formulation, after drying, having a hydrostatic head barrier sufficient to prevent passage of fluids through it, but allow passage of water vapor.
[0017] Another embodiment of this invention is a method for making a multi-layer material which has a hydrostatic head barrier sufficient to prevent passage of fluids through it, but allow passage of water vapor, comprising:
[0018] (a) providing a substrate, such as a nonwoven web, an absorbent pad, a textile fabric, or a nonwoven textile;
[0019] (b) providing a coating formulation comprising a blend of a poly(vinyl acetate) emulsion and a paraffin wax emulsion or a VAE polymer emulsion and a paraffin wax emulsion.
[0020] (c) applying the coating formulation blend onto the substrate; and
[0021] (d) drying the coating formulation.
[0022] Some of the advantages of the coating formulation of this invention are:
[0023] the coating formulation can comprise polymer emulsions that are free of alkylphenol ethoxylate surfactant and have little or no formaldehyde, making them suitable for use on absorbent pads, nonwovens, textiles, or the like, having food or human skin contact;
[0024] the coating formulation can be applied directly to a substrate, eliminating the need for a separate backsheet; and
[0025] the coating formulation attaches directly to a substrate, eliminating the need for an additional procedure to attach a backsheet.
DETAILED DESCRIPTION OF THE INVENTION
[0026] The coating formulation of this invention comprises a poly(vinyl acetate) emulsion blended with a paraffin wax emulsion or a VAE polymer emulsion blended with a paraffin wax emulsion, and optionally a separate protective colloid, such as hydroxyethyl cellulose or poly(vinyl alcohol) (PVOH). The blend comprises 10 to 90 wt % poly(vinyl acetate) emulsion or VAE polymer emulsion, and 10 to 90 wt % paraffin wax emulsion, based on the total weight of the blend.
[0027] The polymer emulsion can be a poly(vinyl acetate) emulsion or a VAE polymer emulsion comprising a polymer of vinyl acetate and ethylene, and optionally one or more other ethylenically unsaturated monomer. Exemplary of other ethylenically unsaturated monomers are C 3 -C 10 alkenoic and alkenedioic acids, such has acrylic acid, crotonic acid, maleic acid, fumaric acid, and itaconic acid, and their mono- and diesters with C 1 -C 18 alkanols, such as methanol, ethanol, propanol, butanol, and 2-ethylhexanol; vinyl halides, such as vinyl chloride; and nitrogen containing monomers, such as nitriles, amides, N-methylol amides, lower alkanoic acid esters of N-methylol amides, lower alkyl ethers of N-methylol amides and allylcarbamates, such as acrylonitrile, acrylamide; and lower alkyl ethers and lower alkanoic acid esters of N-methylol acrylamide and N-methylol allylcarbamate.
[0028] Vinyl acetate in the VAE polymer typically ranges from 70 to 95 wt %, and ethylene ranges from 5 to 30 wt %, based on the total monomers in the copolymer. Up to 10 wt % of other ethylenically unsaturated monomers may be present in the copolymer. The combination of monomers in the VAE polymer is such that the polymer has a T g of −15 to 30° C.
[0029] The poly(vinyl acetate) emulsion and the VAE polymer emulsion can be formed by copolymerization of the monomers in the presence of a stabilizing system by aqueous emulsion polymerization techniques well known in the art. A review of known methods of making poly(vinyl acetate) emulsions can be found in Kirk - Othmer Encyclopedia of Chemical Technology, 4 th ed., Vol. 24, “Vinyl Polymers (Vinyl acetate),” by Cajetan F. Cordeiro, pages 949-958, and 975-977, Wiley, 1997, which is hereby incorporated by reference. VINAC® XX-210 emulsion, supplied Air Products and Chemicals, Inc., is an example of a commercial poly(vinyl acetate) emulsion that is suitable for this invention.
[0030] Examples of known methods of forming VAE polymer emulsions are disclosed in U.S. Pat. Nos. 4,164,489; 4,521,561; and 4,921,898; which are hereby incorporated by reference. AIRFLEX® RB-18 VAE polymer emulsion, available form Air Products and Chemicals, Inc., is an example of a commercial VAE polymer emulsion that can be used in this invention.
[0031] The stabilizing system used in making poly(vinyl acetate) or VAE polymer emulsions can comprise surfactants, emulsifiers, a protective colloid, or a combination of surfactants, emulsifiers, and protective colloid. Poly(vinyl alcohol) is a preferred protective colloid.
[0032] Poly(vinyl acetate) emulsions and VAE polymer emulsions that can be particularly effective in the coating formulation of this invention are PVOH-stabilized polymer emulsions having a T g ranging from −15 to 30° C. A coating formulation that has little (less than about 50 ppm) or no formaldehyde and is free of alkylphenol ethoxylate surfactants can be especially useful for absorbent pads that are in contact with food, and for personal and protective hygiene products.
[0033] Typical paraffin waxes have melt point temperatures of 114 to 160° F. (46 to 71° C.). Solids of the final paraffin wax emulsion can vary from 25% to 60%; more typically, 35 to 55%. The pH of the emulsion can range from 8 to 10, typically 8.9 to 9.8, but is dependent on the process used. The final particle size is dependent on a number of variables including the homogenization which is used at the end of the process. Particle size of the paraffin wax emulsion can vary between 0.02 to 1.5 microns. The particle size for paraffin wax alone is typically 0.2 to 0.8 microns. The paraffin wax emulsion can also be a blend of paraffin wax with other materials, such as polyethylene or ethylene acrylic acid. Emulsion blends of paraffin wax and polyethylene or paraffin wax and ethylene acrylic acid are commercially available from Michelman Inc under the product name Michem emulsion 62330 and Michem emulsion 34935, respectively.
[0034] The paraffin wax emulsion can be prepared by melting refined paraffin wax to a temperature above the melting point of the paraffin. Appropriate emulsifiers, such as stearic acid, oleic acid, diethylamine ethanol, 2-amino-2-methyl-1-propanol, can then be stirred into the wax emulsion at the elevated temperature. A base, such as potassium hydroxide or ammonium hydroxide, can then be dissolved in ethylene glycol or water at elevated temperatures and slowly added to the wax blend while increasing agitation speed of the mixer. After all the water/base mixture has been added to the molten wax, the resulting wax in water emulsion can be passed through a homogenizer to further adjust particle size of the emulsion. After homogenization, the resulting emulsion is cooled, for example, through a heat exchanger, and then filtered and packaged. Michem ME 70950, supplied by Michelman Inc, is an example of a commercially available paraffin wax emulsion that can be used in the blend of this invention.
[0035] The blend can contain other components such as pigments which may improve opacity or color; water soluble polymers or protective colloids, such as poly(vinyl alcohol) and hydroxyethyl cellulose, which may improve fiber bonding and aid in emulsion stability; and hydrophobic additives, such as fluoro surfactants, which may improve the hydrophobic character of the coating. Examples of fluoro surfactants are the perfluoroalkyl acrylic copolymers sold under the tradename Zonyl 8300 or Zonyl 7040, supplied by Ciba Geigy.
[0036] Representative blends are described in the following table:
Broad Preferred Most % dry wt % dry wt Preferred % Component (solids) (solids) dry wt (solids) Polymer Emulsion 10-90 20-80 40-60 Paraffin Wax Emulsion 10-90 20-80 40-60 Water Soluble Polymer or 0-80 0-10 0-5 Protective Colloid Fluoro Surfactant 0-5 0-3 0-2 Pigment 0-10 0-5 0-3 Total 100 100 100
[0037] Representative properties of the blends are summarized in the following table:
Property Broad Range Preferred Range Dry Solids 25-60% 35-55% Viscosity (cps)* 150 to 1200 200-1000 pH 8-10 8.9-9.8
[0038] The polymer emulsion and the paraffin wax emulsion can be blended together by well known methods, such as the following method:
[0039] Add an-appropriate amount of polymer emulsion to a blending vessel;
[0040] Mix in a correct amount of dilution water to form the targeted solids;
[0041] Adjust pH, under agitation, with ammonium hydroxide;
[0042] Under agitation, slowly add the appropriate amount of paraffin wax emulsion;
[0043] Optionally add, under agitation, other components; and
[0044] Continue agitation until ingredients are well blended.
[0045] An example of a substrate to which the coating formulation is applied is a nonwoven fiber web in a single layer or multiple layers. The nonwoven web can be 100% cellulosic web, a blend of synthetic fibers and cellulosic fibers, or all synthetic fibers, such as polyethylene, polypropylene, polyester, and polyamide fibers. The webs can be formed by a dry process, such as air-laid, carded, and rando, or by a wet process. A 100% synthetic web can also be produced through a spun laid or melt blown process or made by a combination of processes. Examples of other substrates include textiles that require a hydrophobic coating that prevents penetration of fluids but allows transmission of water vapor; such as, disposable protective work garments, medical garments, and tablecloths.
[0046] The coating formulations of this invention can be applied as a coating to a substrate using well know coating techniques; for example, spraying, saturation, foam application, print application, and roll application. Coat weights typically range from 5 to 30 g/m 2 of substrate.
[0047] Hydrostatic barrier properties are measured in order to determine the effectiveness of the coating in preventing penetration of fluids through the coating. Hydrostatic barrier properties can be measured according to European Disposables and Nonwovens Association (EDANA) Test Method ERT.120.1-80, Repellency/Wet Barrier Hydrostatic Head Test. When the blend of this invention is applied as a coating to a substrate and dried, the coated substrate will exhibit a hydrostatic head barrier of at least 30 mm, preferably at least 60 mm, using EDANA Test Method ERT.120.1-80, in order to be effective as a barrier coating.
[0048] The invention will be further clarified by a consideration of the following examples, which are intended to be purely exemplary of the use of the invention.
[0049] In all examples, blends were made as described above. The paraffin wax emulsion was Michem ME 70950 supplied by Michelman Inc. The coating was spray applied to the nonwoven substrates. After adjusting the dry solids level of the coating formulations to about 10 and 20% solids, they were sprayed under pressure onto a surface of a nonwoven substrate. The nonwoven substrates were either 100% cellulosic fibers or a structured nonwoven web made from a layer of a 100% cellulosic fibers and a layer of synthetic fibers. The coating was applied to the layer of synthetic fibers in the substrate containing the layer of cellulosic fibers and the layer of synthetic fibers. The coated substrate was then dried in an air oven at temperatures above the boiling point of water; typically 125-160° C. (257-320° F.). Hydrostatic barrier properties of the coated substrate were measured according to EDANA Test Method ERT.120.1-80.
EXAMPLE 1
Comparison of Surfactant-Protected, PVOH-Protected, and Surfactant and PVOH Protected Polymer Emulsions
[0050] Various polymer emulsions were blended with paraffin wax emulsions for the coating formulations. The results of measuring hydrostatic barrier properties of the coated substrates are presented in Table 1.
TABLE 1 Coat weight Coat weight on Hydrostatic Polymer on Cellulose Hydrostatic Structured Head of Emulsion Formula- Web, Head of Web, Coated used in tion, g/m 2 of Coated g/m 2 of Structured Coating % dry substrate Cellulose substrate Web, Sample Formulation solids surface Web, mm surface mm 1 AIRFLEX ® 55% 25.4 40 N/A N/A 4500 EVCI; Surfactant 45% Protected Paraffin Ethylene wax Vinyl Chloride (EVCI) 2 AIRFLEX 50% 23.1 63 27.3 79 192 VAE; Surfactant 50% Protected Paraffin VAE wax 3 AIRFLEX 45% 16.8 71 N/A N/A 100 HS VAE; Surfactant 55% Protected Paraffin VAE wax 4 AIRFLEX 50% 22.6 98 26.6 159 7200 VAE; PVOH / 50% Surfactant Paraffin Protected wax VAE 5 AIRFLEX 55% 25.4 106 25.2 242 RB-18 PVOH VAE; Protected 45% VAE Paraffin wax
[0051] These data show that PVOH-protected VAE polymer emulsions combined with the paraffin wax emulsion (samples 4 and 5) provided the best performance as a barrier coating. The VAE polymer emulsion that is protected with both PVOH and surfactant (sample 4) demonstrated good hydrostatic barrier properties on the cellulose substrate but was not as efficient on the structured substrate compared to sample 5.
EXAMPLE 2
Effect of Varying the Ratio of PVOH-Protected VAE AND Paraffin Wax Emulsion in the Blend
[0052] The ratio of the PVOH-protected AIRFLEX RB 18 VAE polymer emulsion and paraffin wax emulsion was varied to determine the effect of paraffin wax on the hydrostatic head properties of the coating on a 100% cellulosic web. Results are presented in Table 2.
TABLE 2 VAE/ Paraffin Wax formulation, Coat Weight, Hydrostatic Head Result, % dry solids g/m 2 mm 100% VAE 13.7 5 0% Paraffin wax 60% VAE 11.6 58 40% Paraffin wax 50% VAE 12.0 73 50% Paraffin wax 40% VAE 11.6 84 60% Paraffin wax 30% VAE 12.0 93 70% Paraffin wax
[0053] The data show that increasing the paraffin wax level from 0 to 70% of dry solids improved the hydrostatic head barrier properties of the coated substrate.
EXAMPLE 3
Effect of Varying the Amount of Paraffin Wax Emulsion
[0054] Effect of varying the amount of paraffin wax emulsion with AIRFLEX RB-18 VAE polymer emulsion in the coating formulation was studied. Coatings were spray applied at a 12% solids level and dried at 270° F. (132° C.) for 3 minutes. The results of measuring hydrostatic barrier properties of the coated substrates are presented in Table 3 below.
TABLE 3 VAE Polymer Emulsion to Coating Weight Hydrostatic Coating Weight, Hydrostatic Paraffin Wax on Cellulose Head Results, Structured head Result on Emulsion Ratio, Substrate, Cellulose Substrate, Structured % dry Solids g/m 2 Substrate, mm g/m 2 Substrate, mm 100/0 8.5 0 24.5 1 80/20 8.0 4 21.3 110 60/40 11.2 76 25.9 160 40/60 10.1 87 24.8 154 20/80 10.0 97 25.5 159 0/100 10.5 80 24.9 115
[0055] The data show that hydrostatic head increases with increased levels of paraffin wax up to 40% paraffin wax and then remains relatively level or declines.
EXAMPLE 4
Effect of Paraffin Wax Particle Size and Composition on Hydrostatic Barrier Head
[0056] A paraffin wax/polyethylene emulsion blend having a particle size of 0.035 microns was compared to the Michem ME 70950 paraffin wax emulsion having a particle size of 0.35 microns. Both were combined with AIRFLEX RB-18 VAE polymer emulsion. The results of measuring hydrostatic barrier properties of the coated substrates are presented in Table 4 below.
TABLE 4 VAE polymer emulsion/ Paraffin Hydrostatic Head Wax emulsion formulation, Coat Weight, Result, % dry solids g/m 2 mm 55% PVOH protected VAE 28.0 62 45% Paraffin/polyethylene wax 55% PVOH Protected VAE 25.4 106 45% Paraffin wax
[0057] The data show that although both formulations provide good hydrostatic head barrier properties, the formulation containing paraffin wax emulsion alone was more effective than the paraffin wax/polyethylene wax combination.
EXAMPLE 5
Water Vapor Transmission Rate on Nonwoven Substrate Coated with PVOH Protected VAE and Paraffin Wax Emulsion Blend
[0058] The water vapor transmission rate of a 100% cellulose nonwoven substrate coated with a blend of AIRFLEX RB-18 VAE polymer emulsion and paraffin wax emulsion was compared to the nonwoven substrate without the coating. The test followed TAPPI method (Technical Association of the Pulp and Paper Industry) T 448 entitled, “Water vapor transmission rate of sheets at standard temperatures and humidity.” The result of water loss or moisture vapor loss through the nonwoven substrates is shown in the table below:
TABLE 5 Coat Weight Water Loss Rate g/m 2 g/m 2 /24 hours Coated Substrate 21.1 647.4 Base Sheet 0 634.6
[0059] These results show that the coating did not hinder the moisture vapor rate of the nonwoven substrate.
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A waterborne hydrophobic barrier coating formulation comprising a blend of a poly(vinyl acetate) emulsion and a paraffin wax emulsion or a vinyl acetate-ethylene (VAE) polymer emulsion and a paraffin wax emulsion which, when applied to a substrate, such as a nonwoven web, an absorbent pad, or a textile, and dried, has a hydrostatic head barrier sufficient to prevent passage of fluids but allow passage of water vapor through it. A multi-layer material comprising at least one layer of a nonwoven web, an absorbent pad, or a textile, and at least one layer of a blend of a poly(vinyl acetate) emulsion and a paraffin wax emulsion or a VAE polymer emulsion and paraffin wax emulsion. The emulsion blend, after drying, has a hydrostatic head barrier sufficient to prevent passage of fluids through it but allow passage of water vapor.
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RELATED APPLICATIONS
This application claims the benefits of priority under 35 U.S.C. § 119 from French application No. 90 13874, filed Nov. 8, 1990, which is hereby incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to a process and an apparatus for substantial homogenization of a mixture of solid particles and of hydrocarbon vapors to be treated in a fluidized bed of solid particles in a tubular reactor for the cracking of hydrocarbons. More particularly, the invention relates to a process and an apparatus of this type applicable to the catalytic cracking in the fluid state of hydrocarbon feedstocks in a substantially upright tubular reactor operating with an upflow or downflow fluidized bed.
BACKGROUND OF THE INVENTION
It is known that the petroleum industry routinely employs hydrocarbon conversion processes, and particularly cracking processes, in which hydrocarbon molecules having a high molecular weight and a high boiling point are broken down into smaller molecules having a lower boiling point which are suitable for use.
Many of these processes make use of fluidized-bed conversion techniques. In these fluidized bed techniques, solid particles supply the heat necessary for the conversion reaction. The particles are contacted with hydrocarbons for a very short time. The particles can be catalytic.
The process most widely employed at present is the so-called Fluid Catalytic Cracking, or FCC, process. However, other fluidized-bed conversion processes, such as thermal cracking or visbreaking processes, have also been developed.
For the sake of simplicity, the description which follows will be confined to the presentation of the invention within the framework of the catalytic cracking process, it being understood that the invention is applicable to most fluidized-bed hydrocarbon conversion processes in which the feedstock to be cracked is contacted in the vapor phase with solid particles, whether catalytic or not.
Among the most important parameters which determine the efficiency of a cracking reaction are the rapidity with which the feedstock to be treated is contacted with the hot catalyst particles and the homogeneity of distribution of these catalyst particles in the fluidized bed throughout the reaction zone.
The research conducted by Applicants' Assignee with a view to improving the heat transfer between the solid particles in the fluidized bed and the feedstock to be treated has shown that the yields actually obtained in the highest-efficiency cracking units in use up to now are below those to be expected on the basis of theoretical studies, and that this shortfall is due in particular to poor distribution of the catalyst particles in the reaction zone, and especially in the zone where the feedstock to be treated is injected.
In its French and U.S. patent applications, French Nos. 2,585,030, and 89 14787 (and the equivalent U.S. Ser. No. 07/612,322, filed Nov. 13, 1990 pending, incorporated herein by reference), Applicants and the Applicants' Assignee have already proposed means designed to remedy, within the reactor, the axial irregularities in the flow of hot catalyst coming from the regeneration zone and to provide for improved fluidization of the solid catalyst particles upstream of the zone where the hydrocarbons are injected.
However, even when the flow of catalyst is regularized so as to render it as homogeneous as possible upstream of the injection zone of the feedstock to be treated, it has been found that downstream of that zone the distribution of the catalyst particles again becomes heterogeneous, the density of distribution of these particles being higher in the vicinity of the walls of the reactor than in its center.
This natural tendency of the catalyst and the gas phase to segregate due to the interaction between the catalyst and the wall is intensified by the sudden vaporization of the feedstock, which tends to throw the catalyst toward the wall of the reactor, thus producing a concentration of catalyst in the vicinity of the reactor wall. A portion of the catalyst then advances only slowly or even tends to swirl in a direction counter to the motion of the feedstock (an effect known in the art as backmixing) in both an upflow and downflow fluidized beds.
The work carried out by the Applicants and their Assignee have shown that the spread observed between the theoretical yields and those actually obtained are also due in part to this poor distribution of the particles in the reaction zone after injection of the feedstock. This unequal distribution is attributable to the vortices produced by the combined effect of the sudden vaporization of the feedstock and of the high speed of injection thereof, as well as to the chafing of the catalyst particles against the walls. The result is what is known to those skilled in the art as backmixing, which also accounts for the fact that at the periphery of the reactor the catalyst particles are only slightly fluidized, if at all. Consequently, the particles, preferentially disposed at the periphery of the reactor, may stagnate or even flow back along the wall. As a result, the temperature distribution is not uniform throughout the section of the reaction zone downstream of the feedstock injectors. The temperature is excessively high at the periphery of the reactor since the particle density is too high near the walls. These excessively high temperatures cause the feedstock to be overcracked, interfere with the desired liquid conversion; and thus, promote the production of dry gases. Conversely, when the atomized feedstock comes into contact with a stream of catalyst particles that is not dense enough in the central part of the reactor, the quantity of heat supplied by these particles is not sufficient to raise the temperature of the feedstock to the level necessary for the desired reactions to take place; and thus, substantial coking of the catalyst occurs which leads to its deactivation.
OBJECTS OF THE INVENTION
The present invention seeks to remedy the drawbacks of prior art fluidized beds by providing means for a homogeneous distribution of the hot solid particles, and more particularly of the catalyst particles, in an upflow or downflow fluidized-bed hydrocarbon cracking reactor. These means are preferably downstream of the zone of injection into the reactor of the hydrocarbon feedstock to be treated.
The invention further seeks to render the contact between the hot catalyst particles and the hydrocarbon vapors uniform throughout the reaction zone of such a fluidized-bed cracking reactor.
Finally, the invention seeks to render the velocity of the fluids uniform and to prevent any backmixing downstream of the zone of injection of the hydrocarbon feedstock to be cracked in such a hydrocarbon cracking reactor.
SUMMARY OF THE INVENTION
To this end, the present invention provides a process for the homogenization of a mixture of solid particles and of hydrocarbon vapors to be treated in a fluidized bed of hot solid particles within a tubular reactor for the cracking of hydrocarbons. In the process a stream of hot solid particles is preferably continuously fed to the tubular reactor, which is preferably disposed substantially upright; an upward or downward motion is imparted to these particles within the reactor while they are maintained in a dilute fluidized bed; at least one hydrocarbon feedstock to be cracked is brought into contact with these particles by injecting said feedstock into the dilute fluidized bed within the reactor; the gas phase resulting from the contacting of the hydrocarbons with these particles is separated from the latter; the gas phase and the particles so separated are recovered; these particles are optionally treated so as to reactivate them; and then they are recycled to the inlet of the reactor.
The inventive process especially comprises injecting into a tubular reactor for the cracking of a feedstock of hydrocarbons a fluid in the gaseous state. The injecting is preferably in a reaction zone comprising a fluidized bed of hot solid particles and is preferably downstream, more preferably directly downstream, of a zone of injection of the feedstock. The injecting is accomplished more preferably with at least 75 percent of the feedstock being vaporized. To accomplish this, the feedstock is usually vaporized from very fine droplets.
The fluid in the gaseous state is preferably injected into the reactor at a plurality of points evenly distributed over the interior surface of the reactor. These injection points can be distributed either annularly or helically.
This fluid in the gaseous state may be injected into the reactor in a plane which makes an angle of from about 30 to about 150 degrees with the axis of the reactor. The gaseous fluid may also be introduced into the reactor substantially tangentially to the reactor side wall.
The injection of the gaseous fluid directly downstream of the zone of injection of the hydrocarbon feedstock has the effect of causing the particles previously forced against the interior surfaces of the reactor walls by the sudden vaporization of the feedstock to flow back toward the center of the reactor. This results in a more homogeneous distribution of the hot solid particles in the reaction zone of the reactor located downstream of the injection zone of the hydrocarbon feedstock or feedstocks; and consequently in an improved conversion to liquid products from the hydrocarbons to be or being cracked. The improved conversion is accompanied by less deposition of coke on the solid particles and reduced production of dry gases.
The fluid in the gaseous state may be hydrogen, an inert gas such as nitrogen, argon and the like, a light hydrocarbon, for instance a hydrocarbon having from 1 to about 5 carbon atoms, such as methane, ethane, propane, butane or pentane, a vaporized gasoline, or also, and preferably, steam.
The throughput of injected fluid may represent from about 0.005 to about 1 percent by weight of the throughput of solid particles in circulation. The velocity of the fluid in the gaseous state at the outlet of the device injecting that fluid will generally range from about 1 to about 100 meters/second, and preferably from about 20 to about 50 m/s.
The pressure of injection of the fluid in the gaseous state will of course depend on the velocity of injection and on the operating conditions of the reactor.
The temperature of injection of the fluid does not have a significant effect on the temperature profile of the particles downstream of the zone of injection of the feedstock because of the low throughput of injected fluid in relation to the catalytic mass of the circulating fluidized bed.
The invention further provides an apparatus for the substantial homogenization of the mixture of solid particles and of the hydrocarbon vapors to be treated in a fluidized bed of hot solid particles within a tubular reactor for the cracking of hydrocarbons.
The reactor is preferably disposed substantially upright and comprises means for the continuous feeding of a stream of hot solid particles; means for imparting to the particles within the reactor an upward or downward motion while maintaining them in a dilute fluidized bed; means for injection within the reactor into the dilute fluidized bed of at least one hydrocarbon feedstock; means for separating the gas phase resulting from the contacting of the hydrocarbons with said particles; means for the separation and the recovery of the gas phase and of the solid particles; optionally means for the treatment of the recovered particles for the purpose of the reaction; and means for recycling the particles to the inlet of the reactor.
The inventive apparatus especially comprises a means for injection of a fluid in the gaseous state into a tubular reactor for cracking a hydrocarbon feedstock in a fluidized bed of hot solid particles; said reactor having a side wall and the side wall having an interior surface; said means being positioned downstream, preferably directly downstream, of a zone of injection of the hydrocarbon feedstock, and, at one or more points on the interior surface of the side wall of the reactor.
In the apparatus of the invention, the means for injection of the fluid in the gaseous state are preferably located downstream from the feedstock injectors and at a distance therefrom of about 0.5 to about 6 times the radius of the reactor.
In one embodiment of the invention, the injection means for the fluid in the gaseous state may comprise a chamber connected to a source of pressurized gas, said chamber opening into the reactor through at least one orifice. Preferably several chambers are provided and open into the reactor through a plurality of orifices preferably distributed evenly, for example in an annular or helical manner, relative to the axis of the reactor. These orifices are preferably in the form of slots.
In another embodiment of the invention, the means for injection of the gaseous fluid into the reactor may comprise at least one injector connected to a source of pressurized gas. The injection provides a jet of gaseous fluid into the reactor. The injector can be connected to a header which is in turn connected to the source of pressurized gas such that the injector is connected to the source of pressurized gas through the header. The axis of the injector preferably being substantially tangential to the interior surface of the side wall of the reactor. The reactor preferably has several injectors, preferably distributed evenly about its axis, and connected to a header. The header is supplied from the source of pressurized gas. In this embodiment, since the jets of gaseous fluid are introduced tangentially by the injectors, the solid particles near the interior surface of the wall of the reactor are caused to flow away from the surface of the wall, into the interior or center of the reactor, in a circular or helical movement or rotation.
BRIEF DESCRIPTION OF THE DRAWINGS
In this specification and in the accompanying drawings, we have shown and described preferred embodiments of the invention and have suggested various alternatives and modifications thereof; but it is to be understood that these are not intended to be exhaustive and that many other changes and modifications can be made within the scope of the invention. The suggestions herein are selected and included for purposes of illustration in order that others skilled in the art will more fully understand the invention and the principles thereof and will thus be enabled to modify it in a variety of forms, each as may be best suited to the conditions of a particular use.
In the drawings,
FIG. 1 is a diagrammatic view of an installation for the catalytic cracking of hydrocarbons which uses a dilute upflow of catalyst and is equipped with a first preferred embodiment of the homogenization apparatus of the invention;
FIG. 2 is a view of a detail of FIG. 1 in the vicinity of section line III--III on an enlarged scale;
FIG. 3 is a cross-section along the line III--III in FIG. 1;
FIG. 4 is a partial diagrammatic view of a dilute-upflow catalytic cracking reactor equipped with a second preferred embodiment of the homogenization apparatus of the invention;
FIG. 5 is a sectional view of the tangential gaseous-fluid injection device used in the reactor of FIG. 4; and
FIG. 6 is a partial diagrammatic view of a dilute-downflow catalytic cracking reactor equipped with a similar third preferred tangential embodiment of the homogenization apparatus of the invention.
DETAILED DESCRIPTION
Reference will now first be made to FIGS. 1 to 3, wherein a typical unit for catalytic cracking in the fluid state, but equipped with an embodiment of the invention, is depicted. In this unit the regenerated catalyst is introduced at the base of the tubular reactor 1 through a line 2 at a rate determined by the degree to which a valve 3 is opened or closed. The catalyst particles are then propelled toward the top of the reactor by the injection at its base of a gaseous fluid coming from a line 5, this injection being effected by means of a fluid distributor or diffuser 4. The feedstock to be cracked is introduced at a higher level through a line 7 by means of devices 6 for its appropriate atomization into the stream of catalyst particles.
The reactor 1 discharges at its top into an enclosure 8, which here is concentric therewith and in which the gaseous effluents are separated from the catalyst particles by means of a ballistic separator 9 and the deactivated catalyst particles are stripped. The reaction products are separated from any catalyst in a cyclone system 10 which is accommodated in the upper portion of the enclosure 8 and at the top of which a line 11 is provided for discharging the reaction effluents to the outside. The deactivated catalyst particles drop to the bottom of the enclosure 8, where a diffuser 13 supplies the fluidized bed with stripping gas (usually steam) from a line 12. The deactivated catalyst particles so stripped pass to a regenerator 14 through a pipe 15 provided with a control valve 16.
The regenerator 14 here comprises a single regeneration chamber where the deactivated catalyst particles are introduced into the upper portion of the fluidized bed 17 while the flue gases are discharged through a line 18 after having passed through a cyclone 19.
The catalyst particles are regenerated or reactivated, in a fluidized bed, by combustion of the coke and of the hydrocarbons still present on their surface or in their pores, through an injection of air or of oxygen by means of a diffuser 20, supplied from a line 21. The catalyst particles, brought to a high temperature by the heat of combustion, pass back to the base of the reactor 1 through a line 2.
As pointed out above, the hydrocarbon feedstock injected at 6, usually preheated to a temperature of from about 150° to about 400° C., is vaporized virtually instantaneously on contact with the catalyst particles, whose temperature ranges from about 600° to about 900° C. This sudden vaporization has the effect of throwing the catalyst particles toward the side wall of the reactor 1, which results in an uneven distribution of the catalyst particles downstream of the zone of injection of the hydrocarbon feedstock posing a risk of backmixing in the vicinity of the interior surface of the wall 25 of the reactor 1.
To overcome this drawback, a gas stream adapted to force the catalyst particles toward the axis of the reactor is, in accordance with the invention, injected into the reactor directly downstream of the devices 6 for atomization of the hydrocarbon feedstock.
In this embodiment of the invention, four chambers 26, distributed evenly about the axis of the reactor 1, are positioned within the thickness of the wall 25 of the reactor 1. These chambers 26 are connected through pipes 28 to a source of pressurized gas. The chambers 26 each discharge into the interior of the reactor 1 through two slots 29 which are orifices in the wall 25 (through the interior surface thereof). The eight slots 29 are distributed in an annular manner evenly about the axis of the reactor 1.
The jets of gas injected through the slots 29 are directed perpendicularly to the wall 25 toward the interior of the reactor 1, thus preventing the catalyst particles from accumulating in the vicinity of the wall 25, and providing for better contact between the hydrocarbon vapors and the catalyst particles.
The gas used may advantageously be steam of a temperature on the order of about 350° C. and an effective pressure of about 18 bars.
Turning now to FIG. 4 which shows an embodiment wherein the reactor 31 comprises two systems for fluidization of the regenerated catalyst particles recycled to the reactor through the line 32. A first diffuser 34, supplied through the line 35, injects at the base of the reactor 31, below the junction of line 32 and the reactor, a sufficient quantity of fluid to maintain a dense fluidization assuring the homogenization of the particles in this zone. A second diffuser 43, supplied through the line 44 and located downstream of the junction of line 32 and the reactor, then permits injection of a quantity of fluid necessary for creating the conditions of dilute fluidization, with a constant throughput of particles, which then flow upward in the reactor with an axial velocity preferably exceeding about 1.5 meters/second and more preferably ranging from about 2 to about 10 m/s. Reactor 31 is further equipped with injector(s) 36 which is supplied by line 37. Injector(s) 36 is for the introduction and atomization of the hydrocarbon feedstock into reactor 31. See, for example, U.S. Pat. No. 4,832,825, issued May 23, 1989. The improved homogenization derived from the use of the second diffuser 43 is partially disrupted by the effect of injector(s) 36 and subsequent feedstock vaporization.
In accordance with the illustrated, preferred embodiment of the invention, there is provided in the zone located directly downstream of the injector(s) 36 a gaseous fluid injection device which comprises injection tubes 46, fluid distributor 45 and line 47. Injection from the device (45, 46, 47) is preferably tangentially to the wall of the reactor, preferably at four points located symmetrically in a plane normal to the axis of the reactor.
Each of the injection tubes 46 is connected to the fluid distributor 45 which is supplied through line 47. The tangential injections are effected simultaneously at several points of the reactor and thus permit the fluidized phase situated in the vicinity of the wall of the reactor 31 to be set into rotation at a rotative speed that is directly proportional to the quantity of fluid injected. The gaseous fluid is preferably of the same type as that used for fluidization of the catalyst particles.
The angle between the injectors and the plane normal to the axis of symmetry of the reactor is preferably small so that the quantity of fluid to be injected to obtain the required rotation is kept to a minimum. Moreover, it is preferred that these injectors follow as closely as possible, the axial symmetry of the reactor in order to obtain good homogeneity of the fluidized bed.
Finally, FIG. 6 illustrates the use of a homogenization apparatus in accordance with the invention in a tubular reactor with dilute downflow of the catalyst particles.
In this embodiment, the regenerated catalyst particles are introduced into the upper part of the reactor 51 through the line 52 and flow by gravity. A valve 53 is provided for controlling the catalyst throughput. A diffuser 55, supplied with gas through the line 54, maintains the particles in a dense fluidized bed upstream of the valve 53. Downstream of that valve, the catalyst is maintained in a dilute fluidized phase by injection of a second gas into the reactor through the diffuser 58, supplied through the line 57.
The feedstock to be cracked is then introduced into the reactor 51 by means of atomizers 56, aimed in the direction of the stream of particles in the reactor and inclined relative to the axis thereof at an angle of from 30 to 60 degrees, for example.
Directly downstream of these atomizers 56 there is provided a homogenization apparatus in accordance with the invention and of the same type as that shown in FIG. 5, that is, comprising injectors 66 (akin to injection tubes 46) disposed tangentially to the reactor 51 and connected to a distributor 65 (akin to distributor 45) that is supplied with pressurized gas through a line 67 (akin to line 47).
The invention may be further illustrated by the following non-limiting example, many apparent variations of which are possible without departing from the spirit thereof.
EXAMPLE
Two catalytic cracking tests were performed with the same hydrocarbon feedstock in a catalytic cracking unit of the general type of FIG. 1 of the accompanying drawings. One of these tests (Test 1) was run without the use of a homogenization apparatus in accordance with the invention. The other test (Test 2) was carried out with the use of the devices shown in FIGS. 3 and 4.
The feedstock treated was a vacuum distillate having the following characteristics:
Gravity (°API): 21
Sulfur (wt. %): 1.3
Basic nitrogen (ppm by weight): 730
Vanadium (ppm): 2
Nickel (ppm): 1
Conradson carbon (wt. %): 1.5
The operating conditions during the two tests were as shown in Table 1 which follows.
TABLE 1______________________________________ Test 1 Test 2______________________________________Catalyst temperature upstream 734 720of point of injection (°C.)Feedstock injection temperature 250 250(°C.)Reactor outlet temperature (°C.) 529 529Catalyst type Zeolite USY Zeolite USYThroughput of fluid in gaseous 0 2state (t/h)Fluid injected (wt. %), based on 0 0.19fluidized bedVelocity of injection of gaseous -- 40fluid (m/s)______________________________________
The results of Tests 1 and 2 are presented in Table 2 which follows.
TABLE 2______________________________________ Test 1 Test 2______________________________________Dry gases (wt. % of feedstock) 4.65 4.35LPG (wt. %) 16.07 16.38Gasoline (wt. %) 45.82 46.90Light cutter stock (wt. %) 15.82 15.42Slurry (wt. %) 11.79 11.13Coke (wt. %) 5.40 5.36Conversion at 220° C. (vol. %) 72.39 73.45Yield, liquid hydrocarbons above C.sub.3 77.71 78.70______________________________________
As is apparent from this table, the conversion is improved (by more than 1 wt. %), as is the selectivity of the reaction. More gasoline is obtained, and less dry gas and catalyst slurry. Moreover, Table 1 shows an appreciable drop in catalyst temperature upstream of the point of feedstock injection, which translates into a reduction of the regenerator temperature by 14° C.
Having described in detail preferred embodiments of the present invention, it is to be understood that the invention defined by the appended claims is not to be limited by particular details set forth in the above description as many apparent variations thereof are possible without departing from the spirit or scope of the present invention.
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A process for the substantial homogenization of the mixture of hot solid particles and of the hydrocarbon vapors to be treated within a tubular reactor (preferably an FCC unit) for the cracking of hydrocarbons in a fluidized bed of hot solid particles. Directly downstream of the zone of injection, in the reaction zone of the feedstock to be or being treated, usually where at least 75 percent of the droplets of the feedstock are vaporized, there is injected into the reactor a fluid in the gaseous state at one or more points on the interior surface of the side wall of the reactor.
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FIELD
The present disclosure relates to shift assemblies for vehicular transmissions and more particularly to a shift assembly for manual or dual clutch vehicular transmissions having at least two shift forks disposed on a single shift rail.
BACKGROUND
The statements in this section merely provide background information related to the present disclosure and may or may not constitute prior art.
Gear changes in manual and dual clutch transmissions are generally achieved by a synchronizer clutch which is splined to and which rotates with an associated shaft. Adjacent the synchronizer clutch is one or a pair of gears which provide distinct gear or speed ratios. Axial motion of the synchronizer clutch first synchronizes and then couples the gear to the shaft and drive torque is then applied to the engaged gear or shaft.
Axial motion of the synchronizer clutch is commanded by a shift fork which engages a groove in the periphery of the clutch and which is slidably disposed on a shift rail. A linear output of a two or three position actuator may be directly connected to the shift fork or the shift fork may be secured to the shift rail, in which case the actuator is connected to and translates the shift rail.
Especially in the latter configuration, each shift fork requires a dedicated shift rail. Thus, in a five speed transmission which encompasses six gears with reverse, it is necessary to have at least three shift rails, actuators and shift forks. In a six or seven speed transmission (which encompasses seven or eight speeds when reverse is included), it is necessary to have at least four shift rails, actuators and shift forks.
Because each shift rail occupies space in the transmission and requires mounting bosses and/or linear bearings, they add to the complexity and cost of a transmission. Reducing their number is thus desirable.
SUMMARY
The present invention provides several embodiments of a multiple shift fork, single shift rail assembly. In a first embodiment, a stationary shift rail includes pluralities of detenting recesses and cooperating detent assemblies are mounted on the shift forks. Associated actuators translate the shift forks and synchronizer clutches. In a second embodiment, the detenting recesses reside on the outside surface of the shift forks and the detent assemblies are mounted in the transmission housing. In a third embodiment, one shift fork is slidably mounted on the shift rail and includes an external detent assembly. The shift rail itself translates and includes detenting recesses and a second shift fork connected thereto. In every embodiment, more than two shift forks may be associated with a single shift rail if desired.
Thus it is an object of the present invention to provide a single shift rail for a transmission having two shift forks disposed thereon.
It is a further object of the present invention to provide a single shift rail for a manual or a dual clutch transmission having two shift forks disposed thereon.
It is a still further object of the present invention to provide a stationary shift rail having detenting recesses and shift forks carrying detent assemblies.
It is a still further object of the present invention to provide a stationary shift rail which receives two shift fork having detenting recesses on their exterior surfaces.
It is a still further object of the present invention to provide an axially translating shift rail having detenting recesses and a first shift fork secured thereto and a second shift fork slidable thereon with detenting recesses on its exterior surface.
It is a still further object of the present invention to provide a single shift rail having more than two shift forks disposed thereon.
Further objects, advantages and areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
DRAWINGS
The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.
FIG. 1 is diagrammatic, side elevational view in partial section of a portion of a transmission incorporating a first embodiment of a single shift rail assembly according to the present invention;
FIG. 2 is a perspective view of a first embodiment of a single shift rail assembly according to the present invention;
FIG. 3 is diagrammatic, side elevational view in partial section of a portion of a transmission incorporating a second embodiment of a single shift rail assembly according to the present invention;
FIG. 4 is a perspective view of a second embodiment of a single shift rail assembly according to the present invention;
FIG. 5 is diagrammatic, side elevational view in partial section of a portion of a transmission incorporating a third embodiment of a single shift rail assembly according to the present invention; and
FIG. 6 is a perspective view of a third embodiment of a single shift rail assembly according to the present invention
DETAILED DESCRIPTION
The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses.
With reference now to FIG. 1 , a portion of a vehicular transmission is illustrated and generally designated by the reference number 10 . The transmission 10 may be either a manual transmission, a dual clutch transmission (DCT) or other configuration wherein synchronizers and face or dog clutches are utilized to connect a plurality of gears to one or more associated shafts. The transmission 10 includes an exterior housing 12 which typically includes openings, counterbores, shoulders, flanges and the like which locate, receive and retain various components of the transmission 10 .
Supported for rotation within the housing 12 on, for example pairs of ball or tapered roller bearing assemblies 14 are various shafts, one of which, a countershaft or layshaft 16 , is illustrated. The countershaft 16 freely rotatably receives a plurality of spur or preferably helical gears 22 , 24 , 26 and 28 . The gears 22 , 24 , 26 and 28 are paired and in constant mesh with adjacent gears (not illustrated) on one or more adjacent parallel shafts and together these pairs of gears provide a selection of forward (and reverse) speeds or gear ratios.
Between the adjacent gears 22 and 24 is disposed a first synchronizer clutch 30 . The first synchronizer clutch 30 includes both a pair of synchronizer assemblies and a pair of face or dog clutches. The first synchronizer clutch 30 is rotationally connected to the countershaft 16 by a first interengaging male and female spline set 32 but is free to axially translate therealong. When the first synchronizer clutch 30 is translated to the left or right on the countershaft 16 , it exclusively first synchronizes and then positively couples the gear 22 or the gear 24 to the countershaft 16 . The first synchronizer clutch 30 includes a circumferential channel or groove 34 .
Between the adjacent gears 26 and 28 is disposed a second synchronizer clutch 40 . The second synchronizer clutch 40 also includes both a pair of synchronizer assemblies and a pair of face or dog clutches. The second synchronizer clutch 40 is rotationally connected to the countershaft 16 by a second interengaging male and female spline set 42 but is free to axially translate therealong. When the second synchronizer clutch 40 is translated to the left or right on the countershaft 16 , it exclusively first synchronizes and then positively couples the gear 26 or the gear 28 to the countershaft 16 . The first synchronizer clutch 30 also includes a circumferential channel or groove 44 .
Referring now to FIGS. 1 and 2 , secured within suitable blind openings or bores 48 in the housing 12 is a stationary shift rail 50 . The shift rail 50 is preferably a round shaft and may be hollow to reduce its weight. The stationary shift rail 50 is spaced from and parallel to the countershaft 16 . The stationary shift rail 50 defines a first set of detenting recesses 52 A, 52 B and 52 C and a second set of detenting recesses 54 A, 54 B and 54 C which are spaced from the first set of recesses 52 A, 52 B and 52 C.
Received for bi-directional axial translation on the stationary shift rail 50 are a first shift fork assembly 60 and a second shift fork assembly 80 . The first shift fork assembly 60 includes a first cylindrical or tubular body 62 defining a through passageway 64 that receives the stationary shift rail 50 . A first pair of linear ball bearing assemblies 66 disposed within the passageway 64 and generally proximate the ends of the tubular body 62 reduce friction and stabilize the first shift fork assembly 60 on the stationary shift rail 50 . A first shift fork 68 extends radially from the cylindrical body 62 and includes a first yoke 70 which engages the circumferential channel or groove 34 in the first synchronizer clutch 30 .
The first cylindrical body 62 also includes a first radially oriented housing 72 which receives a first detent ball 74 which is biased toward the stationary shift rail 50 and the first set of detenting recesses 52 A, 52 B and 52 C by a first compression spring 76 . The output of a first bi-directionally translating, three position electric, pneumatic or hydraulic actuator or operator 78 is coupled to a first arm or extension 79 of the first cylindrical body 62 of the first shift fork assembly 60 and translates from a center, neutral position illustrated in FIG. 1 to a first active position to the left to cause synchronization and engagement of the first gear 22 or to a second active position the right to cause synchronization and engagement of the second gear 24 .
When the first shift fork assembly 60 is in the left, first active position, the detent ball 74 is in the first detenting recess 52 A and cooperation between the first recess 52 A and the detent ball 74 resists motion of the first shift fork assembly 60 . When the first shift fork assembly 60 is in the center, neutral position, the detent ball 74 is in the second detenting recess 52 B and cooperation between the second recess 52 B and the detent ball 74 again resists motion of the first shift fork assembly 60 . When the first shift fork assembly 60 is in the right, second active position, the detent ball 74 is in the third detenting recess 52 C and cooperation between the third recess 52 C and the detent ball 74 once again resists motion of the first shift fork assembly 60 .
The second shift fork assembly 80 also includes a second cylindrical or tubular body 82 defining a through passageway 84 that receives the stationary shift rail 50 . A second pair of linear ball bearing assemblies 86 disposed generally proximate the ends of the second tubular body 82 reduce friction and stabilize the second shift fork assembly 80 on the stationary shift rail 50 . A second shift fork 88 extends radially from the second cylindrical body 82 and includes a second yoke 90 which engages the circumferential channel or groove 34 in the second synchronizer clutch 40 .
The second cylindrical body 82 also includes a radially oriented second housing 92 which receives a second detent ball 94 which is biased toward the stationary shift rail 50 and the second set of detenting recesses 54 A, 54 B and 54 C by a second compression spring 96 . The output of a second bi-directionally translating, three position electric, pneumatic or hydraulic actuator or operator 98 is coupled by a second arm or extension 99 to the second cylindrical body 82 of the second shift fork assembly 80 and translates from a center, neutral position illustrated in FIG. 1 to a first active position to the left to cause synchronization and engagement of the third gear 26 or to a second active position the right to cause synchronization and engagement of the fourth gear 28 .
When the second shift fork assembly 80 is in the left, first active position, the second detent ball 94 is in the first detenting recess 54 A and cooperation between the first recess 54 A and the detent ball 94 resists motion of the second shift fork assembly 80 . When the second shift fork assembly 80 is in the center, neutral position, the second detent ball 94 is in the second detenting recess 54 B and cooperation between the second recess 54 B and the detent ball 94 again resists motion of the second shift fork assembly 80 . When the second shift fork assembly 80 is in the right, second active position, the second detent ball 94 is in the third detenting recess 54 C and cooperation between the third recess 54 C and the detent ball 94 once again resists motion of the second shift fork assembly 80 .
Referring now to FIGS. 3 and 4 , a second embodiment of a single shift rail assembly according to the present invention is illustrated and generally designated by the reference number 100 . FIG. 3 includes a portion of a vehicular transmission 110 . As above, the transmission 110 may be either a manual transmission, a dual clutch transmission (DCT) or other configuration wherein synchronizers and face or dog clutches are utilized to connect a plurality of gears to one or more associated shafts. The transmission 110 includes an exterior housing 112 which receives and supports, among other components, pairs of ball or tapered roller bearing assemblies 114 which, in turn, rotatably support a countershaft or layshaft 116 . The countershaft 116 freely rotatably receives a plurality of spur or preferably helical gears 122 , 124 , 126 and 128 . The gears 122 , 124 , 126 and 128 are paired and in constant mesh with adjacent gears (not illustrated) on one or more adjacent parallel shafts and together these pairs of gears provide a selection of forward (and reverse) speeds or gear ratios.
Between the adjacent gears 122 and 124 is disposed a first synchronizer clutch 130 . The first synchronizer clutch 130 includes both a pair of synchronizer assemblies and a pair of face or dog clutches. The first synchronizer clutch 130 is rotationally connected to the countershaft 116 by a first interengaging male and female spline set 132 but is free to axially translate therealong. When the first synchronizer clutch 130 is translated to the left or right on the countershaft 116 , it exclusively first synchronizes and then positively couples the gear 122 or the gear 124 to the countershaft 116 . The first synchronizer clutch 130 includes a circumferential channel or groove 134 .
Between the adjacent gears 126 and 128 is disposed a second synchronizer clutch 140 . The second synchronizer clutch 140 also includes both a pair of synchronizer assemblies and a pair of face or dog clutches. The second synchronizer clutch 140 is rotationally connected to the countershaft 116 by a second interengaging male and female spline set 142 but is free to axially translate therealong. When the second synchronizer clutch 140 is translated to the left or right on the countershaft 116 , it exclusively first synchronizes and then positively couples the gear 126 or the gear 128 to the countershaft 116 . The second synchronizer clutch 140 also includes a circumferential channel or groove 144 .
Secured within suitable blind openings or bores 148 in the housing 112 is a stationary shift rail 150 . The stationary shift rail 150 is spaced from and parallel to the countershaft 116 . Disposed in general radial alignment with the first synchronizer clutch 130 for bi-directional translation on the stationary shift rail 150 is a first shift fork assembly 160 and in general radial alignment with the second synchronizer clutch 140 for bi-directional translation on the stationary shift rail 150 is a second shift fork assembly 190 .
The first shift fork assembly 160 includes a first, relatively short cylindrical or tubular body 162 defining a through passageway 164 that receives the stationary shift rail 150 . A first pair of linear ball bearing assemblies 166 disposed within the passageway 164 generally occupy the length of the tubular body 162 , reduce friction and stabilize the first shift fork assembly 160 on the stationary shift rail 150 . A first shift fork 168 extends radially from the cylindrical body 162 and includes a first yoke 170 which engages the circumferential channel or groove 134 in the first synchronizer clutch 130 .
The first cylindrical body 162 also includes a first set of detenting recesses 172 A, 172 B and 172 C. The first set of detenting recesses 172 A, 172 B and 172 C are circumferentially and radially aligned with a first detenting assembly 174 which includes a detent ball 176 received within a cylindrical housing 178 which extends from and is secured to the housing 112 . A compression spring 182 biases the detent ball 176 toward the recesses 172 A, 172 B and 172 C. The cylindrical or tubular body 162 includes an arm or extension 184 that is coupled to the output of a first bi-directionally translating, three position electric, pneumatic or hydraulic actuator or operator 186 . The output of the actuator or operator 186 translates from a center, neutral position illustrated in FIG. 3 to a first active position to the left to cause synchronization and engagement of the first gear 122 or to a second active position the right to cause synchronization and engagement of the second gear 124 .
When the first shift fork assembly 160 is in the left, first active position, the detent ball 176 is in the third detenting recess 172 C and the first detenting assembly 174 resists motion of the first shift fork assembly 160 . When the first shift fork assembly 160 is in the center, neutral position, the detent ball 176 is in the second detenting recess 172 B and the first detenting assembly 174 again resists motion of the first shift fork assembly 160 . When the first shift fork assembly 160 is in the right, second active position, the detent ball 176 is in the first detenting recess 172 A and the first detenting assembly 174 once again resists motion of the first shift fork assembly 160 .
The second shift fork assembly 190 includes a second, relatively short cylindrical or tubular body 192 defining a through passageway 194 that receives the stationary shift rail 150 . A second pair of linear ball bearing assemblies 196 disposed within the passageway 194 generally occupy the length of the tubular body 192 , reduce friction and stabilize the second shift fork assembly 190 on the stationary shift rail 150 . A second shift fork 198 extends radially from the second cylindrical body 192 and includes a second yoke 200 which engages the circumferential channel or groove 144 in the second synchronizer clutch 140 .
The second cylindrical body 192 also includes a second set of detenting recesses 202 A, 202 B and 202 C. The second set of detenting recesses 202 A, 202 B and 202 C are circumferentially and radially aligned with a second detenting assembly 204 which includes a detent ball 206 received within a cylindrical housing 208 which extends from and is secured to the housing 112 . A second compression spring 212 biases the detent ball 206 toward the second set of recesses 202 A, 202 B and 202 C. The cylindrical or tubular body 192 includes an arm or extension 214 that is coupled to the output of a second bi-directionally translating, three position electric, pneumatic or hydraulic actuator or operator 216 . The output of the actuator or operator 216 translates from a center, neutral position illustrated in FIG. 3 to a first active position to the left to cause synchronization and engagement of the third gear 126 or to a second active position the right to cause synchronization and engagement of the fourth gear 128 .
When the second shift fork assembly 190 is in the left, first active position, the detent ball 206 is in the third detenting recess 202 C and the second detenting assembly 204 resists motion of the second shift fork assembly 190 . When the second shift fork assembly 190 is in the center, neutral position, the detent ball 206 is in the second detenting recess 202 B and the second detenting assembly 204 again resists motion of the second shift fork assembly 190 . When the second shift fork assembly 190 is in the right, second active position, the detent ball 206 is in the first detenting recess 202 A and the second detenting assembly 204 once again resists motion of the second shift fork assembly 190 .
Referring now to FIGS. 5 and 6 , a third embodiment of a single shift rail assembly according to the present invention is illustrated and generally designated by the reference number 300 . FIG. 5 includes a portion of a vehicular transmission 310 . Once again, the transmission 310 may be either a manual transmission, a dual clutch transmission (DCT) or other configuration wherein synchronizers and face or dog clutches are utilized to connect a plurality of gears to one or more associated shafts. The transmission 310 includes an exterior housing 312 which receives and supports, among other components, pairs of ball or tapered roller bearing assemblies 314 which, in turn, rotatably support a countershaft or layshaft 316 . The countershaft 316 freely rotatably receives a plurality of spur or preferably helical gears 322 , 324 , 326 and 328 . The gears 322 , 324 , 326 and 328 are paired and in constant mesh with adjacent gears (not illustrated) on one or more adjacent parallel shafts and together these pairs of gears provide a selection of forward (and reverse) speeds or gear ratios.
Between the adjacent gears 322 and 324 is disposed a first synchronizer clutch 330 . The first synchronizer clutch 330 includes both a pair of synchronizer assemblies and a pair of face or dog clutches. The first synchronizer clutch 330 is rotationally connected to the countershaft 316 by a first interengaging male and female spline set 332 but is free to axially translate therealong. When the first synchronizer clutch 330 is translated to the left or right on the countershaft 316 , it exclusively first synchronizes and then positively couples the gear 322 or the gear 324 to the countershaft 316 . The first synchronizer clutch 330 includes a circumferential channel or groove 334 .
Between the adjacent gears 326 and 328 is disposed a second synchronizer clutch 340 . The second synchronizer clutch 340 also includes both a pair of synchronizer assemblies and a pair of face or dog clutches. The second synchronizer clutch 340 is rotationally connected to the countershaft 316 by a second interengaging male and female spline set 342 but is free to axially translate therealong. When the second synchronizer clutch 340 is translated to the left or right on the countershaft 316 , it exclusively first synchronizes and then positively couples the gear 326 or the gear 328 to the countershaft 316 . The second synchronizer clutch 340 also includes a circumferential channel or groove 344 .
Secured within an aligned, opposed pair of mounting openings or bores 346 in the housing 312 are a respective pair of linear ball bearing assemblies 348 which slidably and rotatably receive a single shift rail 350 . Axial translation of the single shift rail 350 is, however, limited by the adjacent walls of the housing 312 and rotation is inhibited by components attached to the shift rail 350 . The shift rail 350 is spaced from and parallel to the countershaft 316 . Disposed in general radial alignment with the first synchronizer clutch 330 for bi-directional translation on the single shift rail 350 is a first shift fork assembly 360 and in general radial alignment with the second synchronizer clutch 340 for bi-directional translation with the single shift rail 350 is a second shift fork assembly 390 .
The first shift fork assembly 360 includes a first, relatively long cylindrical or tubular body 362 defining a through passageway 364 that receives the single shift rail 350 . A pair of linear ball bearing assemblies 366 disposed proximate the ends of the passageway 364 reduce friction and stabilize the first shift fork assembly 360 on the stationary shift rail 350 . A first shift fork 368 extends radially from the cylindrical body 362 and includes a first yoke 370 which engages the circumferential channel or groove 334 in the first synchronizer clutch 330 .
The first cylindrical body 362 also includes a first set of detenting recesses 372 A, 372 B and 372 C. The first set of detenting recesses 372 A, 372 B and 372 C are circumferentially and radially aligned with a first detenting assembly 374 which includes a detent ball 376 received within a cylindrical housing 378 which extends from and is secured to the housing 312 . A compression spring 382 biases the detent ball 376 toward the recesses 372 A, 372 B and 372 C. The cylindrical or tubular body 362 includes an arm or extension 384 that is coupled to the output of a first bi-directionally translating, three position electric, pneumatic or hydraulic actuator or operator 386 . The output of the first actuator or operator 386 translates the first shift fork assembly 360 from a center, neutral position illustrated in FIG. 5 to a first active position to the left to cause synchronization and engagement of the first gear 322 or to a second active position the right to cause synchronization and engagement of the second gear 324 .
When the first shift fork assembly 360 is in the left, first active position, the detent ball 376 is in the third detenting recess 372 C and the first detenting assembly 374 resists motion of the first shift fork assembly 360 . When the first shift fork assembly 360 is in the center, neutral position, the detent ball 376 is in the second detenting recess 372 B and the first detenting assembly 374 again resists motion of the first shift fork assembly 360 . When the first shift fork assembly 360 is in the right, second active position, the detent ball 376 is in the first detenting recess 372 A and the first detenting assembly 374 once again resists motion of the first shift fork assembly 360 .
The second shift fork assembly 390 includes a second, relatively short cylindrical or tubular body 392 defining a through passageway 394 that receives the single shift rail 350 . The second cylindrical or tubular body 392 is secured to the single shift rail 350 by any suitable fastener such as a set screw 396 , a taper pin or an interference fit. A second shift fork 398 extends radially from the second cylindrical body 392 and includes a second yoke 400 which engages the circumferential channel or groove 344 in the second synchronizer clutch 340 . The second cylindrical or tubular body 392 also includes an arm or extension 404 that is coupled to the output of a second bi-directionally translating, three position electric, pneumatic or hydraulic actuator or operator 406 . The output of the second actuator or operator 406 translates the second shift fork 398 from a center, neutral position illustrated in FIG. 5 to a first active position to the left to cause synchronization and engagement of the third gear 326 or to a second active position the right to cause synchronization and engagement of the fourth gear 328 .
Disposed adjacent the first detenting assembly 374 is a second detenting assembly 414 . The second detenting assembly 414 includes a second detent ball 416 received within a cylindrical housing 418 which extends from and is secured to the housing 312 . The cylindrical housing 418 is aligned with the single shift rail 350 . A compression spring 420 biases the detent ball 416 toward a plurality of detenting recesses 422 A, 422 B and 422 C in the single shift rail 350 .
When the second shift fork assembly 390 is in the left, first active position, the second detent ball 416 is in the third detenting recess 422 C and the second detenting assembly 414 resists motion of the single shift rail 350 and the second shift fork assembly 390 . When the second shift fork assembly 390 is in the center, neutral position, the detent ball 416 is in the second detenting recess 422 B and the second detenting assembly 414 again resists motion of the shift rail 350 and the second shift fork assembly 390 . When the second shift fork assembly 390 is in the right, second active position, the detent ball 416 is in the first detenting recess 422 A and the second detenting assembly 414 once again resists motion of the shift rail 350 and the second shift fork assembly 390 .
It will be appreciated that, first of all, the relatively long and the relatively short shift fork bodies, e.g. 362 and 162 , of the various embodiments may be arranged and exchanged on the single shift rails 50 , 150 and 350 as desired and, second of all, use of the relatively short shift fork bodies may readily permit the disposition of three shift fork bodies on either the stationary shift rail 50 of the first embodiment or the sliding shift rail 350 of the third embodiment.
It will also be appreciated that typically two of the single shift rail assemblies disclosed and claimed herein will be utilized with any given transmission. This configuration represents a reduction in at least one and possibly two shift rails as well as a reduction in the number of mounting features necessarily required to support such shift rails.
The description of the invention is merely exemplary in nature and variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.
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A multiple shift fork, single shift rail assembly reduces weight and complexity in manual and dual clutch transmissions. In a first embodiment, a stationary shift rail includes pluralities of detenting recesses and cooperating detent assemblies are mounted on the shift forks. Associated actuators translate the shift forks and synchronizer clutches. In a second embodiment, the detenting recesses reside on the outside surface of the shift forks and the detent assemblies are mounted in the transmission housing. In a third embodiment, one shift fork is slidably mounted on the shift rail and includes an external detent assembly. The shift rail itself translates and includes detenting recesses and a second shift fork connected thereto.
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CROSS REFERENCE TO RELATED APPLICATION
This application claims the benefit of U.S. Provisional Patent Application No. 61/419,017, filed Dec. 2, 2010, the disclosure of which is incorporated by reference herein in its entirety.
TECHNICAL FIELD
This invention relates to pressure-sensitive adhesives and adhesive sealants prepared from isobutylene copolymers, and tape articles prepared therefrom. The pressure-sensitive adhesives are characterized by exhibiting an overall balance of adhesive and cohesive characteristics and exceptional adhesion to low surface-energy substrates.
BACKGROUND
Pressure-sensitive tapes are virtually ubiquitous in the home and workplace. In its simplest configuration, a pressure-sensitive tape comprises an adhesive and a backing, and the overall construction is tacky at the use temperature and adheres to a variety of substrates using only moderate pressure to form the bond. In this fashion, pressure-sensitive tapes constitute a complete, self-contained bonding system.
According to the Pressure-Sensitive Tape Council, pressure-sensitive adhesives (PSAs) are known to possess properties including the following: (1) aggressive and permanent tack, (2) adherence with no more than finger pressure, (3) sufficient ability to hold onto an adherend, and (4) sufficient cohesive strength to be removed cleanly from the adherend. Materials that have been found to function well as PSAs include polymers designed and formulated to exhibit the requisite viscoelastic properties resulting in a desired balance of tack, peel adhesion, and shear holding power. PSAs are characterized by being normally tacky at room temperature (e.g., 20° C.). PSAs do not embrace compositions merely because they are sticky or adhere to a surface.
These requirements are assessed generally by means of tests which are designed to individually measure tack, adhesion (peel strength), and cohesion (shear holding power), as noted in A. V. Pocius in Adhesion and Adhesives Technology: An Introduction, 2 nd Ed., Hanser Gardner Publication, Cincinnati, Ohio, 2002. These measurements taken together constitute the balance of properties often used to characterize a PSA.
With broadened use of pressure-sensitive tapes over the years, performance requirements have become more demanding. Shear holding capability, for example, which originally was intended for applications supporting modest loads at room temperature, has now increased substantially for many applications in terms of operating temperature and load. So-called high performance pressure-sensitive tapes are those capable of supporting loads at elevated temperatures for 10,000 minutes. Increased shear holding capability has generally been accomplished by crosslinking the PSA, although considerable care must be exercised so that high levels of tack and adhesion are retained in order to retain the aforementioned balance of properties.
There are a wide variety of pressure sensitive adhesive (PSA) materials available today that include natural crude or synthetic rubbers, block copolymers, and acrylic ester based polymeric compositions. Central to all PSAs is a desired balance of adhesion and cohesion that is often achieved by optimizing the physical properties of the acrylic elastomer, such as glass transition temperature and modulus. For example, if the glass transition temperature (T g ) or modulus of the elastomer is too high and above the Dahlquist criterion for tack (storage modulus of 3×10 6 dynes/cm 2 at room temperature and oscillation frequency of 1 Hz), the material will not be tacky and is not useful by itself as a PSA material. Often in this case, low molecular weight, high T g resin polymers (tackifiers) or low molecular weight, low T g polymers (plasticizers) are often used to modulate the T g and modulus into an optimal PSA range.
SUMMARY
The adhesive (co)polymers of this disclosure comprise: a) an isobutylene copolymer having pendent alkoxysilane groups, b) a tackifier, and c) optionally a non-functionalized poly(isobutylene) polymer. In one aspect the pressure-sensitive adhesive comprises the interpolymerized reaction product of isobutylene and at least one monomer having a pendent alkoxysilane group.
The pressure-sensitive adhesives of this disclosure provide the desired balance of tack, peel adhesion, and shear holding power, and further conform to the Dahlquist criteria; i.e. the modulus of the adhesive at the application temperature, typically room temperature, is less than 3×10 6 dynes/cm at a frequency of 1 Hz.
In some embodiments, hot melt adhesive compositions are provided which applied to substrates from the melt. Such hot melt adhesive compositions are substantially solvent-free. Hot melt adhesives are versatile and widely used in industrial applications, such as bookbindings, cardboard boxes, plastic parts and wooden articles, among others. They are generally 100% solid adhesives with application temperatures which vary from about 150 to about 180° C.,
In recent years, there has been a significant increase of the usage of low surface energy, olefin-based thermoplastics (e.g., polyethylene, polypropylene, ethylene propylene diene monomer rubber (EPDM)) in automotives, paints, appliances and electronics markets. The advantages of the new materials include affordable cost, easy processibility, and excellent mechanical properties. However, this trend creates a challenge in terms of making adhesive bonds to these low energy surfaces.
When considering adhesive tapes, pressure-sensitive adhesive (PSA) tapes are the easiest to use, but for the most part, pressure-sensitive adhesives do not adhere well to low surface energy substrates. Additionally, most PSAs are unsuited for uses requiring good internal (cohesive) strength at elevated temperatures. For example, rubber-resin PSAs tend to soften and degrade when heated. PSAs based on styrene-containing block copolymers also do not retain good internal strength when heated, because styrene has a low T g and so softens at moderately elevated temperatures. Currently the bonding to low surface-energy surfaces is achieved by priming the substrate with polar liquid followed by application of PSAs. Even after this two step process, the existing PSAs do not fulfill customer requirements. There is need to develop primerless LSE PSAs at competitive cost but still with the most optimized properties.
Recently, polyisobutylene (PIB) has been considered as an attractive material for low surface energy (LSE) bonding applications due to its excellent adhering properties on olefin-based thermoplastics. In addition, the excellent moisture and oxygen barrier properties of PIB suggest that PIB-based materials have potential use in electronic and photovoltaic encapsulation applications. In spite of its beneficial properties, low cohesive strength of the material has limited the uses for high shear applications. Another possible application for PIB-based material is in the medical adhesive field. Most acrylate-based PSAs are not suitable for medical application since acrylate PSAs tend to give off toxic vapors at elevated temperatures. Acrylate-based PSAs typically contain monomeric materials which, even at ordinary room temperatures, exude odors that make acrylate PSA tapes generally unsuitable for medical uses. Polyisobutylene PSAs are often used for medical uses because they are physiologically inert, but again they tend to be deficient in internal strength.
The adhesive compositions of the present disclosure provide an improved pressure-sensitive and hot-melt adhesive composition which may be adhered to a variety of substrates, including low surface-energy (LSE) substrates, within a wide temperature range and provide good adhesive strength and holding characteristics. The adhesive compositions are easily handled, and are environmentally friendly due to the low volatile organic compound (VOC) content, such as solvents. The adhesive compositions of the present disclosure further provide a pressure-sensitive adhesive article, such as adhesive tapes and sealants.
As used herein
“Alkyl” means a linear or branched, cyclic or acrylic, saturated monovalent hydrocarbon having from one to about twelve carbon atoms, e.g., methyl, ethyl, 1-propyl, 2-propyl, pentyl, and the like.
“Alkylene” means a linear unsaturated divalent hydrocarbon having from one to about twelve carbon atoms or a branched saturated divalent hydrocarbon having from three to about twelve carbon atoms, e.g., methylene, ethylene, propylene, 2-methylpropylene, pentylene, hexylene, and the like.
“Alkenyl” means a linear saturated monovalent hydrocarbon having from one to about twelve carbon atoms or a branched unsaturated hydrocarbon having from three to about twelve carbon atoms.
“Aryl” means a monovalent aromatic, such as phenyl, naphthyl and the like.
“Arylene” means a polyvalent, aromatic, such as phenylene, naphthalene, and the like.
“Aralkylene” means a group defined above with an aryl group attached to the alkylene, e.g., benzyl, 1-naphthylethyl, and the like.
As used herein, “(hetero)hydrocarbyl” is inclusive of hydrocarbyl alkyl and aryl groups, and heterohydrocarbyl heteroalkyl and heteroaryl groups, the later comprising one or more catenary (in-chain) heteroatoms such as ether or amino groups. Heterohydrocarbyl may optionally contain one or more catenary (in-chain) functional groups including ester, amide, urea, urethane, and carbonate functional groups. Unless otherwise indicated, the non-polymeric (hetero)hydrocarbyl groups typically contain from 1 to 60 carbon atoms. Some examples of such heterohydrocarbyls as used herein include, but are not limited to, methoxy, ethoxy, propoxy, 4-diphenylaminobutyl, 2-(2′-phenoxyethoxy)ethyl, 3,6-dioxaheptyl, 3,6-dioxahexyl-6-phenyl, in addition to those described for “alkyl”, “heteroalkyl”, “aryl”, and “heteroaryl” supra.
DETAILED DESCRIPTION
The adhesive copolymer comprises: a) an isobutylene copolymer having pendent alkoxysilane groups, b) a tackifier, and c) optionally a non-functionalized poly(isobutylene) polymer. In one aspect the pressure-sensitive adhesive comprises the interpolymerized reaction product of isobutylene and at least one monomer having pendent alkoxysilane groups.
The isobutylene copolymer having pendent alkoxysilane groups may be represented by the general formula:
R 6 —R 2 Si(OR 3 ) x (R 3 ) 3-x ] y
where R 6 represents the polymeric isobutylene having at least 20 repeat units, R 2 is a (hetero)hydrocarbyl group, subscript y represents a fraction of those repeat units substituted by the alkoxysilane group, and each R 3 is an alkyl group or aryl group. Typically 1 to 5 percent of the repeat units of the isobutylene copolymer will be substituted by alkoxysilane groups. Preferably R 2 is a saturated alkylene of 1 to ten carbon atoms, optional containing one or more.
The monomer units having pendent, moisture curable alkoxysilane groups may be derived from halogenated butyl rubber and are of the general formula:
wherein Q is a multivalent, preferably divalent, linking group, Z is alkoxysilane group and R 7 is H or CH 3 . More particularly, the isobutylene copolymer may be of the formula;
wherein a is at least 20, and at least one of b and c are at least one, Q is a polyvalent linking group and Z is a alkoxysilane group; or
wherein a and d are at least 1, preferably a is at least 20, d is at least one, R 7 is H or CH 3 , Q is a polyvalent linking group and Z is alkoxysilane group.
With respect to the copolymers of Formulas I and II it will be recognized that the monomer units having the subscript “a” are interpolymerized isobutylene monomer units. The -Q-Z moiety may be of the formula:
—R 1 —X 1 —R 2 Si(OR 3 ) x (R 3 ) 3-x ] q III
where
R 1 is a multivalent alkylene or arylene group, X 1 is —O—, —O 2 C—, —NR 4 —, where R 4 is H or C 1 -C 4 alkyl; R 2 is a (hetero)hydrocarbyl group, preferably a saturated alkylene, R 3 is an alkyl group or aryl group, x is 1 to 3, preferably 3, and q is 1 or 2.
Further, with regard to Formulas I and II, the subscripts “b” and “c” or “d” are chosen such that the copolymer comprises 1 to 20 wt. % of the respective monomer units: e.g. b and c are such that the -Q-Z containing monomer units comprise 1 to 20 wt. % of the copolymer.
The copolymers of isobutylene may include those wherein isobutylene is copolymerized with another monomer, which may be subsequently modified to include the pendent unsaturated group. Synthetic rubbers include butyl rubbers which are copolymers of mostly isobutylene with a small amount of isoprene, for example, butyl rubbers available under the tradenames VISTANEX (Exxon Chemical Co.) and JSR BUTYL (Japan Butyl Co., Ltd.). In some embodiments, the copolymers are substantially homopolymers of isobutylene, for example, polyisobutylene resins, which may be subsequently modified to include the pendent unsaturated group, available under the tradenames OPPANOL (BASF AG) and GLISSOPAL (BASF AG). The copolymers also include copolymers of mostly isobutylene with n-butene or butadiene, which may be subsequently modified to include the pendent unsaturated group. In some embodiments, a mixture of copolymers may be used, i.e., the first polyisobutylene comprises a homopolymer of isobutylene and the second polyisobutylene comprises butyl rubber, or the first polyisobutylene comprises butyl rubber and the second polyisobutylene comprises a copolymer of isobutylene, subsequently modified. Blends of isobutylene homopolymer and modified poly(isobutylene) are also contemplated.
The isobutylene copolymer may comprise a random copolymer of isobutylene and modified paramethylstyrene units, wherein said random copolymer contains 1 to 20% by weight of said modified paramethylstyrene units and has a crosslinked structure. This random copolymer is, for example, commercially available from Exxon Chemical Co. under the trade name of EXXPRO series, and examples thereof include MDX90-10, MDX89-4. A portion of the methyl groups at the para-position of this paramethylstyrene can be brominated to form a site for the subsequent nucleophilic displacement by a compound of Formula III. Accordingly, a crosslinked structure can be formed by the technique described in detail hereinafter. Particularly, regarding the copolymer MDX90-10, 1.2% by mol of paramethylstyrene, which is contained in the copolymer in the amount of 7.5% by weight, is brominated. Regarding MDX89-4, 0.75% by mol of paramethylstyrene, which is contained in the copolymer in the amount of 5% by weight, is brominated. In addition, bromination of paramethylstyrene and random polymerization between isobutylene and paramethylstyrene, for the purpose of producing a random copolymer, can be performed by known techniques.
Paramethylstyrene monomer units can also impart heat resistance and strength to the copolymer by the cohesive force and hardness of paramethylstyrene itself. To obtain such an effect, paramethylstyrene is preferably contained in the copolymer in amounts of greater than zero, preferably about 1 to 20 parts by weight based on the total amount of the copolymer. When the amount of paramethylstyrene is smaller than 1 part by weight, the cohesive force is insufficient and it becomes difficult to obtain enough adhesion to endure practical use. On the other hand, when the amount of paramethylstyrene is larger than 20 parts by weight, the flexibility is drastically lowered and the adhesion as an important characteristics of the adhesive disappears and, therefore, it becomes impossible to refer to it as a pressure-sensitive adhesive any longer.
The copolymer of Formulas I and II are generally prepared by nucleophilic displacement of commercially available halogenated PIBs, including halogenated poly(isobutylene-co-methylstyrene), halogenated poly(isobutylene-co-isoprene). Alternatively, a non-halogenated PIB-based material may be halogenated, then subsequently substituted. The halogen moiety in those materials allows introduction of the pendent alkoxysilane groups using a nucleophilic alkoxysilane of the formula:
H—X 1 —R 2 Si(OR 3 ) x (R 3 ) 3-x ] q ,
where
X 1 is —O—, —S—, —NR 4 —, where R 4 is H or C 1 -C 4 alkyl; R 2 is a multivalent saturated or unsaturated alkylene or arylene, R 3 is an alkyl group or aryl group, x is 1 to 3, preferably 3, and q is 1 or 2.
The nucleophilic alkoxysilane compound has at least two reactive functional groups. The first reactive functional group “HX 1 —” is capable of displacing the halogen atom of the halogenated isobutylene copolymer. For example, reactive functionalities such as amino, hydroxyl, or mercaptan can displace with complementary halide, such as chloro-, bromo-, iodo present on the isobutylene copolymer.
Additional information on nucleophilic alkoxysilane compounds may be found in U.S. Pat. No. 5,204,219, issued to Van Ooij et al., U.S. Pat. No. 5,464,900, issued to Stofko et al., and U.S. Pat. No. 5,639,546, issued to Bilkadi and European Patent Application No. 0,372,756 A2.
Useful thiosilanes include (mercaptomethyl)dimethylethoxysilane, (mercaptomethyl)methyldiethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltriethoxysilane(mercaptomethyl)methyldiethoxysilane.
Some aminosilanes useful in the practice of this disclosure are described in U.S. Pat. No. 4,378,250 (Treadway et al., incorporated herein by reference) and include aminoethyltriethoxysilane, β-aminoethyltrimethoxysilane, β-aminoethyltriethoxysilane, β-aminoethyltributoxysilane, β-aminoethyltripropoxysilane, α-amino-ethyltrimethoxysilane, α-aminoethyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyltributoxysilane, γ-aminopropyltripropoxysilane, β-aminopropyltrimethoxysilane, β-aminopropyltriethoxysilane, β-aminopropyltripropoxysilane, β-aminopropyltributoxysilane, α-aminopropyltrimethoxysilane, α-aminopropyltriethoxysilane, α-aminopropyltributoxysilane, and α-aminopropyltripropoxysilane.
The reaction scheme involves a displacement reaction with a “nucleophilic alkoxysilane compound”; an organic compound with at least one nucleophilic functional group and least one alkoxysilane group.
where
R 7 is H or CH 3 , X 1 is —S—, —NR 4 —, where R 4 is H or C 1 -C 4 alkyl, R 1 is a multivalent alkylene or arylene, R 2 is a multivalent saturated or unsaturated alkylene or arylene, R 3 is an alkyl group or aryl group, x is 1 to 3, preferably 3, q is 1 or 2; X 2 is a leaving group such as a halide, and preferably a bromide.
The adhesives of this disclosure optional further comprise non-functional poly(isobutylene) polymers. The unfunctionalized isobutylene (co)polymeric synthetic rubbers are generally resins having a polyisobutylene main or a side chain. In some embodiments, the isobutylene (co)polymers are substantially homopolymers of isobutylene, for example, poly(isobutylene) resins available under the tradenames OPPANOL (BASF AG) and GLISSOPAL (BASF AG). In some embodiments, the isobutylene (co)polymeric resins comprise copolymers of isobutylene, for example, synthetic rubbers wherein isobutylene is copolymerized with another monomer. Synthetic rubbers include butyl rubbers which are copolymers of mostly isobutylene with a small amount of isoprene, for example, butyl rubbers available under the tradenames VISTANEX (Exxon Chemical Co.) and JSR BUTYL (Japan Butyl Co., Ltd.). Synthetic rubbers also include copolymers of mostly isobutylene with n-butene or butadiene. In some embodiments, a mixture of isobutylene homopolymer and butyl rubber may be used, i.e., a first polyisobutylene comprises a homopolymer of isobutylene and the second polyisobutylene comprises butyl rubber, or a first polyisobutylene comprises butyl rubber and a second polyisobutylene comprises a homopolymer of isobutylene.
The unfunctionalized isobutylene (co)polymeric synthetic rubber (e.g. PIB) material typically has substantially higher molecular weight than the amine-functionalized (e.g. PIB) synthetic rubber material (described further below). In some embodiments, the weight average molecular weight (M w ) of the unfunctionalized isobutylene (co)polymeric synthetic rubber (e.g. PIB) is at least 35,000 grams per mole, at least 100,000 grams per mole, at least 250,000 grams per mole, at least 500,000 grams per mole, or even at least 1,000,000 grams per mole. The weight average molecular weight is typically no greater than 4,000,000 g/mole.
The unfunctionalized isobutylene (co)polymeric synthetic rubber can be a homopolymer, copolymer, or a mixture thereof. Copolymers can be random or block copolymers. Block copolymers can include the polyisobutylene sections in the main backbone, in a side chain, or in both the main backbone and a side chain of the polymer. The polyisobutylene material is typically prepared by polymerizing isobutylene alone or by polymerizing isobutylene plus additional ethylenically unsaturated monomers, such as isoprene, in the presence of a Lewis Acid catalyst such as aluminum chloride, boron trichloride (with titanium tetrachloride as a co-catalyst), or boron trifluoride.
Unfunctionalized isobutylene (co)polymeric rubbers are commercially available from several manufacturers. Homopolymers are commercially available, for example, under the trade designation OPPANOL (e.g., OPPANOL B10, B15, B30, B50, B80, B100, B150, and B200) from BASF Corp. (Florham Park, N.J.). These polymers often have a weight average molecular weight (M w ) in the range of about 35,000 to 4,000,000 grams per mole. Still other exemplary homopolymers are commercially available from United Chemical Products (UCP) of St. Petersburg, Russia in a wide range of molecular weights. For example, homopolymers commercially available from UCP under the trade designation SDG have a viscosity average molecular weight (M v ) in the range of about 35,000 to 65,000 grams per mole. Homopolymers commercially available from UCP under the trade designation EFROLEN have a viscosity average molecular weight (M v ) in the range of about 480,000 to about 4,000,000 grams per mole. Homopolymers commercially available from UCP under the trade designation JHY have a viscosity average molecular weight in the range of about 3000 to about 55,000 grams per mole. These homopolymers typically do not have reactive double bonds. It is appreciated that the unfunctionalized (e.g. PIB) synthetic rubber may have a very small concentration of reactive double bonds or other functional groups that are residual to the polymerization thereof. The concentration of such reactive double bonds or other functional groups is typically less than 5, 4, 3, or 2 mol %. Such olefinic unsaturations are also typically not suitable functional groups for formation of covalent bonds via free-radical polymerization.
The concentration of unfunctionalized isobutylene (co)polymeric synthetic rubber material in the pressure sensitive adhesive composition is typically less than 50 wt. %, preferably greater than 10 wt. %, relative to the total weight of the composition.
Conventional adhesives do not adhere well to certain substrates, such as certain types of automotive paints and low energy surfaces. Efforts have been made to improve the adhesion of adhesives, i.e., develop more aggressive tack, to these types of surfaces; tackifying the base polymer is commonly practiced. Various types of tackifiers include phenol modified terpenes, hydrocarbon resins such as polyvinyl cyclohexane and poly(t-butyl styrene), and rosin esters such as glycerol esters of rosin and pentaerythritol esters of rosin.
Various types of tackifiers include phenol-modified terpenes and rosin esters such as glycerol esters of rosin and pentaerythritol esters of rosin that are available under the trade names Nuroz™, Nutac™ (Newport Industries), Permalyn™, Staybelite™, Foral™ (Eastman). Also available are hydrocarbon resin tackifiers that typically come from C5 and C9 monomers by products of naphtha cracking and are available under the trade names Piccotac™, Eastotac™, Regalrez™, Regalite™ (Eastman), Arkon™ (Arakawa), Norsolene™, Wintack™ (Cray Valley), Nevtack, LX (Neville Chemical Co.), Hikotack™, Hikorez™ (Kolon Chemical), Novares™ (Rutgers N.V.), Quintone™ (Zeon), Escorez™ (Exxonmobile Chemical), Nures™, and H-Rez™ (Newport Industries).
Conventional tackified pressure-sensitive adhesives can also appear cloudy, demonstrating a loss in the characteristic transparency found in many conventional pressure-sensitive adhesive compositions. The cloudiness is an indication of limited or incomplete compatibility of the tackifier and the polymers. The reduced compatibility can lead to a degradation of adhesive properties on aging, as evidenced by a loss of tack or reduced peel adhesion. In some cases, the addition of a tackifier to an adhesive composition can be clear and appear to be compatible. However, after removing the solvent, curing the adhesive, or on aging, the adhesive can become cloudy, indicating some incompatibility between the tackifier and acrylic base polymer.
In many embodiments, the present disclosure provides tackified adhesive compositions that overcome problems noted in the art. The tackifier is preferably selected from a material that is essentially free of any ethylenically or acetylenically unsaturated bonds. The tackifier includes, but is not limited to, hydrogenated rosin resins, hydrogenated and esterified rosin resins, hydrogenated terpene resins, aliphatic petroleum resins, aromatic petroleum resins, alicyclic petroleum resins obtained by hydrogenating aromatic petroleum resins, and the like. Preferably, the tackifier used is selected from hydrogenated C 9 petroleum resins such as but not limited to Regalrez™ tackifiers (Eastman) or Arkon™ (Arakawa) tackifiers. Such “hydrophobic tackifiers”, may be used in amounts of greater than zero, typically less than 50 wt. %, preferably greater than 1 wt. %, relative to the total weight of the composition.
Plasticizers may also be used in the adhesive formulation to provide wetting action and/or viscosity control. These plasticizers are well known in the art and may include hydrocarbon oils, liquid or soft tackifiers, including liquid hydrocarbon resins, liquid polyterpenes, liquid poly(isobutylenes) such as Glissopal™, and the like, waxes, and mixtures of oils. A plasticizer may be present in the pressure sensitive adhesive of the present invention in an amount of from is typically less than 30 wt. %, preferably greater than 1 wt. %, relative to the total weight of the composition.
In many embodiments, the adhesive composition may comprise comprising
a) greater than 30 wt. %, preferably greater than 50 wt. %, isobutylene copolymer having pendent alkoxysilane groups; b) 0 to 50 wt. % of tackifier, preferably 1 to 50 wt. %, and c) 0 to 50 wt. % non-functional poly(isobutylene), preferably 10 to 50 wt. %.
The adhesives of the present invention may be coated upon a variety of flexible and inflexible backing materials using conventional coating techniques to produce adhesive-coated materials. Flexible substrates are defined herein as any material which is conventionally utilized as a tape backing or may be of any other flexible material. Examples include, but are not limited to plastic films such as polypropylene, polyethylene, polyvinyl chloride, polyester (polyethylene terephthalate), polycarbonate, polymethyl(meth)acrylate (PMMA), cellulose acetate, cellulose triacetate, and ethyl cellulose. Foam backings may be used. Examples of inflexible substrates include, but are not limited to, metal, metallized polymeric film, indium tin oxide coated glass and polyester, PMMA plate, polycarbonate plate, glass, or ceramic sheet material. The adhesive-coated sheet materials may take the form of any article conventionally known to be utilized with adhesive compositions such as labels, tapes, signs, covers, marking indices, display components, touch panels, and the like. Flexible backing materials having microreplicated surfaces are also contemplated.
On exposure to water or humidity, the alkoxysilane groups hydrolyze to silanol groups, which crosslink the polymer by forming siloxane linkages with adjacent alkoxysilane groups. As a result of the hydrolysis and crosslinking, the adhesive's cohesive strength properties increase with time. The crosslinking and formation of siloxane groups is illustrated in Scheme V, where R 6 represents the polymeric isobutylene radical having at least 20 repeat units. No additional crosslinking agents, such as di- or polyvalent alcohols or amines are necessary to form the ionic crosslinking. It will be understood that siloxane bonds are labile in the presence of moisture, and constantly cleave and reform.
where
R 2 is a multivalent saturated or unsaturated alkylene or arylene R 3 is an alkyl group or aryl group, x is 1 to 3, preferably 3,
R 6 represents the polymeric isobutylene radical having at least 20 repeat units
Faster crosslinking is achieved in the presence of a silanol condensation catalyst. Suitable catalysts include organic metal compounds such as tin carboxylates and titanium esters or chelates, e.g., tetrabutyltitanate and bis(acetylacetonyl)di-isopropyl titanate; organic bases such as ethylamine, hexylamine and piperidine; and acids such as the mineral acids and fatty acids. The preferred catalysts are the organic tin compounds, for example, dibutyltindilaurate, dibutyltindiacetate and dibutyltindioctoate. Typically, such catalysts are added in amounts between one part to about 3 parts by weight per 100 parts by weight of the moisture-curable polyisobutylene polymer.
In the absence of a silanol condensation catalyst, hydrolysis proceeds slowly at low relative humidity (less than 50% relative humidity), so that it may be desirable to subject the coated tapes to conditions of high relative humidity (at least 50%) and moderately elevated temperature (e.g., 30.degree. to 100.degree. C.), preferably immediately following the coating step. Instead, the coating can be caused to pick up moisture (e.g., by being exposed to steam), and the moisture-bearing tape can be wound up into a jumbo roll, wherein the support can have a release coating on its backside, which is then heated in an oven until the PSA coating has become moisture-cured. Another technique involves blending a PIB polymer with one to ten weight percent, preferably one to two weight percent of a hydrated salt prior to coating and later heating the tape to produce the moisture-curing, either while the tape is in roll form or after it has been put to use. Suitable hydrated salts include CuSO 4 .5H 2 O, MgSO 4 .7H 2 O, BaSO 4 .2H 2 O, BaCl2.2H 2 O, CaSO 4 .2H 2 O.
The above-described compositions are coated on a substrate using conventional coating techniques modified as appropriate to the particular substrate. For example, these compositions can be applied to a variety of solid substrates by methods such as roller coating, flow coating, dip coating, spin coating, spray coating, knife coating, and die coating. These various methods of coating allow the compositions to be placed on the substrate at variable thicknesses thus allowing a wider range of use of the compositions. Coating thicknesses may vary, but coating thicknesses of 2-500 microns (dry thickness), preferably about 25 to 250 microns, are contemplated.
In one embodiment, the adhesive composition may be coated directly on a substrate (from a solution, emulsion or 100% solids) and exposed to a high humidity environment to effect the hydrolysis. In another embodiment adhesive composition may be coated as before, but passively hydrolyzed by exposure to ambient humidity. In either method, the isobutylene polymer may comprise both alkoxysilane groups and the siloxane linkages, as a function of the degree of crosslinking.
In some embodiments, the adhesive compositions, particularly pressure-sensitive adhesive compositions, are applied as a solvent solution or dispersion, the solvent evaporated, and the adhesive composition crosslinked on moisture. Crosslinking of such solvent-based compositions may occur before, but preferably occurs after coating and solvent removal. Suitable solvents such as alkanes, ethyl acetate, toluene and tetrahydrofuran which are unreactive with the functional groups of the components of the copolymer
Conventional hot melt adhesives have poor adhesion at temperatures above their melting points and low heat resistance, which limits the use. Since conventional hot melt adhesives cannot maintain sufficient adhesion at high temperatures, they cannot be used in many applications. The instant compositions provide reactive hot melt adhesives that overcome this deficiency. As the instant adhesive compositions crosslink after bonding, they provide improved heat resistance.
The adhesives of the present disclosure are particularly useful for forming strong bonds to low surface energy (LSE) substrates. As used herein, low surface energy substrates are those having a surface energy of less than about 45 dynes per centimeter, more typically less than about 40 dynes per centimeter, and most typically less than about 35 dynes per centimeter. Included among such materials are polypropylene, polyethylene (e.g., high density polyethylene or HDPE), polystyrene and poly(methyl methacrylate) (PMMA). Other substrates may also have properties of low surface energy due to a residue, such as an oil residue or a film such as paint, being on the surface of the substrate. However, even though the present adhesive bonds well to low surface energy surfaces, the invention is not limited to being bonded to low surface energy substrates, as it has been found that the inventive adhesive can also bond well to higher surface energy substrates such as, for example, other plastics, ceramics, glass and metals.
The substrate is selected depending on the particular application in which it is to be used. For example, the adhesive can be applied to sheeting products, (e.g., decorative graphics and reflective products), label stock, and tape backings. Additionally, the adhesive may be applied directly onto a substrate such as an automotive panel, or a glass window so that another substrate or object can be attached to the panel or window.
The adhesive can also be provided in the form of a pressure-sensitive adhesive transfer tape in which at least one layer of the adhesive is disposed on a release liner for application to a permanent substrate at a later time. The adhesive can also be provided as a single-coated or double-coated tape in which the adhesive is disposed on a permanent backing. Backings can be made from plastics (e.g., polypropylene, including biaxially oriented polypropylene, vinyl, polyethylene, polyester such as polyethylene terephthalate), nonwovens (e.g., papers, cloths, nonwoven scrims), metal foils, foams (e.g., polyacrylic, polyethylene, polyurethane, neoprene), and the like. Foams are commercially available from various suppliers such as 3M Co., Voltek, Sekisui, and others. The foam may be formed as a coextruded sheet with the adhesive on one or both sides of the foam, or the adhesive may be laminated to it. When the adhesive is laminated to a foam, it may be desirable to treat the surface to improve the adhesion of the adhesive to the foam or to any of the other types of backings. Such treatments are typically selected based on the nature of the materials of the adhesive and of the foam or backing and include primers and surface modifications (e.g., corona treatment, surface abrasion). Additional tape constructions include those described in U.S. Pat. No. 5,602,221 (Bennett et al.), incorporated herein by reference. Those skilled in the art will also know that other additives such as fillers, antioxidants, stabilizers, and colorants may be blended with the adhesive for beneficial properties.
For a single-sided tape, the side of the backing surface opposite that where the adhesive is disposed is typically coated with a suitable release material. Release materials are known and include materials such as, for example, silicone, polyethylene, polycarbamate, polyacrylics, and the like. For double coated tapes, another layer of adhesive is disposed on the backing surface opposite that where the adhesive of the invention is disposed. The other layer of adhesive can be different from the adhesive of the invention, e.g., a conventional acrylic PSA, or it can be the same adhesive as the invention, with the same or a different formulation. Double coated tapes are typically carried on a release liner.
EXAMPLES
As used in this section, the word polymer may be a homopolymer or a co-polymer, or a mixture thereof.
All tapes were conditioned at 23° C. and 50% relative humidity before testing for 90° Peel Adhesion and Static Shear Strength. The humidity provided sufficient moisture to cure the adhesive on the tapes.
The designation pph indicates parts per one hundred parts of solid polymer by weight, i.e, the weight of all of the polyisobutylene (co-)polymers, but not the weight of liquid polyisobutylene.
Test Methods:
90° Angle Peel Adhesion Strength Test.
Peel adhesion strength was measured at a 90° angle using an IMASS SP-200 slip/peel tester (available from IMASS, Inc., Accord Mass.) at a peel rate of 305 mm/minute (12 inches/minute) using the procedure described in ASTM International standard, D3330, Method F. Test panels were prepared by wiping the panels with a tissue wetted with the corresponding solvents shown in Table 1 using heavy hand pressure to wipe the panel 8-10 times. This procedure was repeated two more times with clean tissues wetted with solvent. The cleaned panel was allowed to dry. The adhesive tape was cut into strips measuring 1.27 cm×20 cm (½ in.×8 in.) and the strips were rolled down onto the cleaned panel with a 2.0 kg (4.5 lb.) rubber roller using 2 passes. Two samples were tested for each example and averaged values were expressed in N/dm. Failure mode was noted and recorded as COH—cohesive, i.e., the adhesive split leaving residue on both the tape and test surface, ADH—adhesive, i.e., the adhesive peeled cleanly from the test surface, and 2-B (2-Bond)—the adhesive peeled away from the backing
TABLE 1 Peel Adhesion Test Panel Materials Material Solvent HDPE—High density polyethylene Isopropyl alcohol PP—Polypropylene Isopropyl alcohol EPDM—Ethylene/propylene/diene monomer Isopropyl alcohol copolymer Santoprene—thermoplastic Elastomer (TPE) Isopropyl alcohol based on EPDM and Polypropylene SS—Stainless Steel Heptane Glass—Soda-lime glass Heptane
Static Shear Strength
The static shear strength was evaluated as described in ASTM International standard, D3654, Procedure A at 23° C. and 50% RH (relative humidity) using a 1000 g load. Tape test samples measuring 1.27 cm×15.24 cm (½ in.×6 in.) were adhered to 1.5 inch by 2 inch stainless steel (SS) panels using the method to clean the panel and adhere the tape described in the peel adhesion test. The tape overlapped the panel by 1.27 cm×2.5 cm. and the free end of the strip was folded over itself on the adhesive side, and then folded again. A hook was hung in the second fold and secured by stapling the tape above the hook. The 1000 g weight was attached to the hook and the panel was hung in a room set at 23° C./50% RH. The time to failure in minutes was recorded. If no failure was observed after 10,000 minutes, the test was stopped and a value of >10,000 minutes was recorded. The mode of failure described in the peel adhesion test was also noted.
Gel Content
The gel content by weight percent was determined according to the method described in the ASTM International standard, D3616-95. A round test specimen measuring 63/64 inch in diameter was die-cut from a tape coated with the polymer, and catalyst if used, and cured. The specimen and a tarred mesh basket measuring 3.8 cm×3.8 cm were weighed to the nearest 0.1 mg and the original specimen weight was determined (Original Wt). The basket and specimen were placed in a capped jar containing sufficient toluene to cover the sample. After 24 hours the basket and specimen were removed from the toluene, drained and dried in an oven at 120° C. for 30 minutes, and then weighed to determine the weight of unextracted gel on a backing (Residual Wt). The percent gel, by weight, (Wt % Gel) was determined by calculating the weight % of the unextracted portion to the original sample. A disc of the uncoated polyester backing material of the same size as the specimen was die-cut and weighed as the tare weight for the backing (Backing Wt). The formula used for percent gel determination is shown below.
Wt % Gel=[(Residual Wt−Backing wt.)/(Original Wt−Backing wt.)]×100
Materials Used for Examples
The following materials are available from ExxonMobil Corporation (Baytown, Tex.)
EXXPRO 3745 copolymer—Brominated poly(isobutylene co-methylstyrene) ESCOREZ 1310—Hydrocarbon based tackifier
The follow materials are available from Sigma Aldrich (St. Louis, Mo.)
TBAB—Tetrabutylammonium bromide CsCO 3 —Cesium carbonate Silane—3-Mercaptopropyltrimethoxysilane Toluene Acetone Lanxess 2030 copolymer (Bromo Butyl Rubber)—Copolymer of brominated isobutylene-isoprene; Lanxess; Frieberg Switzerland OPPANOL B15 polymer—unfunctionalized synthetic rubber (PIB; medium MW—80 kg/mol); BASF; Florham Park N.J. GLISSOPAL 1000 polymer—liquid plasticizer (unfunctionalized PIB; low MW—1000 g/mol); BASF; Florham Park N.J. DBTDL catalyst—Di-n-butyltin dilaurate; Alfa Aesar; Ward Hill Mass. Backing—Hostaphan® 3SAB primed polyester film; Mitsubishi; Greer S.C.
Preparation of Polymers
Polymer 1: 3-Mercaptopropyl Trimethoxysilane Modified Brominated Poly(Isobutylene-Co-Methylstyrene)
A polymer composition was prepared by adding 16.00 g of EXXPRO 3745 copolymer, 1.14 g 3-mercaptopropyl trimethoxysilane, 1.50 g Cs 2 CO 3 , and 144.00 g of toluene to a three-neck, round-bottomed flask equipped with a Dean-Stark trap, a thermometer, and a nitrogen inlet. The contents of the flask were stirred with a magnetic stir bar under nitrogen at room temperature. Once the copolymer completely dissolved, the flask was heated to 120° C., at which temperature the Cs 2 CO 3 reacted with the thiol (—SH) moiety on 3-mercaptopropyl trimethoxysilane to produce nucleophile cesium thiolate (—S − Cs + ) and water. The produced water was azeotropically removed from the system through the Dean-Stark trap. After 5 hours at 120° C. the reaction was cooled to room temperature and the composition was vacuum filtered through a fitted funnel (5 μm pore size) to remove unreacted Cs 2 CO 3 and salts. The filtrate was poured into acetone to coagulate the alkoxysilane modified polymer. The isolated polymer was washed with fresh acetone three times to remove residual 3-mercaptopropyl trimethoxysilane. The alkoxysilane modified polymer was filtered and then dried in a vacuum oven for 12 hours at 50° C., and then cooled to room temperature.
Polymer 2: 3-Mercaptopropyl Trimethoxysilane Modified Brominated Poly(Isobutylene-Co-Isoprene)
A polymer composition was prepared by adding 16.00 g of LANXESS 2030 copolymer, 1.14 g of 3-mercaptopropyl trimethoxysilane, 0.64 g of TBAB, and 144.00 g of toluene to a three-neck, round-bottomed flask equipped with a reflux condenser, a thermometer, and a nitrogen inlet. The contents of the flask were stirred with a magnetic stir bar under nitrogen at room temperature. Once all the components completely dissolved, the flask was heated to 105° C. After 5 hours, the reaction was cooled to room temperature and the composition was poured into acetone to coagulate the alkoxysilane modified polymer. The isolated polymer was washed with fresh acetone three times to remove residual silane and TBAB. The alkoxysilane modified polymer was filtered and then dried in a vacuum oven for 12 hours at 50° C., and then cooled to room temperature.
Examples 1-3 and Control Compositions C1-C3
Adhesive compositions for Examples 1-3 were prepared by adding the amounts of Polymer 1 and Oppanol B15 polymer shown in Table 2, 400 parts of toluene, 10 pph (parts per hundred parts of polymer) of ESCOREZ 1310 tackifier, 10 pph of Glissopal 1000 polyisobutylene, and 0.2 pph catalyst (DBTDL) in 100 mL glass jars. The jars were capped and mixed on a roller mill overnight. The resulting compositions were knife-coated onto a 6 inch by 25 inch strip of backing (Hostaphan® 3SAB) to a thickness of about 15 mils wet. The coated film was dried in an oven set at 70° C. for 20 minutes to provide a tape having an adhesive coating thickness of approximately 2 mils. After conditioning, the tapes were tested for Static Shear Strength and 90° Peel Adhesion Strength. Results are shown in Tables 2 and 3.
Adhesive compositions for Examples C1, C2, and C3, were prepared according to the procedure for Examples 1-3, and having the amounts of EXXPRO 3745 (unmodified copolymer) and Oppanol B15 shown in Table 2, 10 pph tackifier, 10 pph plasticizer and 400 parts of toluene. The adhesive compositions were coated into tapes according to the procedure for Examples 1-3. No catalyst was added to these compositions.
Tapes were conditioned and tested for Peel Adhesive and Static Shear Strength. Test results are shown in Tables 2 and 3.
TABLE 2
Adhesive Compositions and Shear Properties
Shear
Exxpro 3745
Polymer 1
Oppanol B15
Strength
Failure
Ex
(parts)
(parts)
(parts)
(min)
Mode
1
0
100
0
>10,000
—
2
0
70
30
>10,000
—
3
0
40
60
1,500
COH
C1
100
0
0
3500
COH
C2
70
0
30
300
COH
C3
40
0
60
50
COH
TABLE 3
90° Peel Adhesion of Moisture-Cured PIB-based PSAs
90° Peel Adhesion Strength (N/dm)
Example
HDPE
PP
EPDM
Santoprene
SS
Glass
1
7
35
34
10
23
31
2
9
31
44
70
32
32
3
13
39
59
57
35
39
Examples 4-6 and Control Compositions C4-C6
Adhesive compositions for Examples 4-6 were prepared by adding the amounts of Polymer 2 and Oppanol B15 polymer shown in Table 4, 400 parts of toluene, 10 pph of ESCOREZ 1310 tackifier, 10 pph of Glissopal 1000 polyisobutylene, and 0.2 pph catalyst (DBTDL) in 100 mL glass jars. The jars were capped and mixed on a roller mill overnight. The adhesive compositions were used to prepare tapes having a dry adhesive coating thickness of approximately 2 mils according to the procedure for Examples 1-3.
Adhesive compositions for Examples C4, C5, and C6, were prepared according to the procedure for Examples 4-6 having the amounts of LANXESS 2030 (unmodified copolymer) and Oppanol B15 shown in Table 2, 10 pph of tackifier, 10 pph of plasticizer, and 400 parts of toluene. The adhesives were coated into tapes according to the procedure for Examples 1-3. No catalyst was added to these compositions.
Tapes were conditioned and tested for Peel Adhesive and Static Shear Strength. Test results are shown Tables 4 and 5.
TABLE 4
Coating Formulation and Shear Property
Shear
LANXESS 2030
Polymer 2
Oppanol B15
Strength
Failure
Ex
(parts)
(parts)
(parts)
(min)
Mode
4
0
100
0
>10,000
—
5
0
70
30
70,000
—
6
0
40
60
1,600
COH
C4
100
0
0
840
COH
C5
70
0
30
160
COH
C6
40
0
60
40
COH
TABLE 5
90° Peel Adhesion of Moisture-Cured PIB-based PSAs
Example
90° Peel Strength (N/dm)
Number
HDPE
PP
EPDM
Santoprene
SS
Glass
4
19
52
45
79
31
25
5
29
72
75
95
53
36
6
22
41
70
35
120
52
Examples 7-8
Preparation of Tapes for Gel Content Testing
An adhesive composition for Example 7 was prepared for Gel Content Testing by dissolving 100 parts of Polymer 1 in 400 parts of toluene and adding 0.2 pph catalyst (DBTDL) in a capped jar and mixing overnight on a roller mill. The polymer dispersion was coated into a tape and dried according to the procedure for Examples 1-3.
A tape was prepared in the same manner for Example 8 except that Polymer 2 was used in the adhesive composition.
The tapes were conditioned and test for Gel Content. Results are shown in Table 6.
TABLE 6
Percent Gel Test Results
Example
Polymer
Thickness (mil)
Gel Content - %
7
1
2
61
8
2
2
59
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The disclose provides pressure-sensitive adhesives and adhesive sealants prepared from alkoxysilane modified, crosslinked isobutylene copolymers, and tape articles prepared therefrom.
| 2
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FIELD OF INVENTION
This invention relates to image recording, and more particularly to a system and method for simultaneously capturing substantially identical images of a subject on a video camera and a photographic film camera operating in synchronism with a single flash illumination.
BACKGROUND OF INVENTION
It is well known to be desirable to simultaneously record substantially identical photographic film and electronic video images of a subject. This is particularly useful in portrait photography, although other photographic situations may equally benefit from this capability. The recorded video images can be used, for example, as electronic "proofs" of the picture composition before the expense of developing and printing of the photographic negatives is incurred.
The use of flash illumination is required for most indoor and some outdoor photographic opportunities. During such flash exposure, the film camera lens remains open for a predetermined period of time, while the flash illumination is provided during a window of time within this predetermined period. Because the flash illumination substantially entirely defines the exposure onto the photographic film, and because the flash illumination time is short, the operation of the film and video cameras must be carefully synchronized to obtain substantially identical images.
U.S. Pat. No. 4,805,037, Noble et al, describes one form of synchronization system in which the synchronization is such that when the film camera captures a photographic image of the subject, the video camera captures substantially the same view of the subject as an image frame comprised of two consecutive interlaced video fields, the flash illumination being substantially entirely and equally distributed between the two fields of video information. The capturing of the video image is accomplished by inhibiting, during the flash illumination, any transfer of information from the image sensor in the video camera. Upon termination of the flash illumination, the next two video fields are transferred to provide a full video frame of the subject of interest. Although satisfactory for its intended purpose, this arrangement requires substantial modification of a conventional video camera and related synchronization circuits to provide means to inhibit the image transfer process and thus adds undesirable complexity and cost to the system.
It is therefore an object of the present invention, to provide a method and system for recording images of a subject in electronic and photosensitive mediums in which the film and video cameras are synchronized to capture substantially identical film and full frame video images with a single flash illumination.
It is another object of the present invention to provide a method and system of image recording system allowing simultaneous capture of flash illuminated film and video images of a subject that is simple and inexpensive to implement.
It is yet another object of the invention to provide a method and system of the type described wherein the flash illumination can be initiated in a random manner with respect to the operation of the video components of the system while maintaining full and even flash illumination distribution across a complete video frame (either interlace or non-interlace type) following completion of the flash illumination.
SUMMARY OF INVENTION
Thus, in accordance with the invention, an image recording system for simultaneously recording images of a subject in electronic and photosensitive media comprises a photographic camera for recording a photographic image of the subject on the photosensitive medium, the photographic camera including means for supplying a flash request signal and a video camera including a solid state image sensor for capturing an image of the subject on the image sensor, the video camera including video signal processing circuits for converting image information from the image sensor into a video signal and a timing generator including image transfer clocking means for controlling transfer of the image information from the image sensor to the video processing circuits. The system of the invention further includes flash means responsive to the flash request signal for flash illuminating the subject to allow simultaneous image capture by the photographic and video cameras and includes reset means responsive to the flash request signal for interrupting operation of the clocking means at the beginning of a flash illumination and for restarting the clocking means following conclusion of the flash illumination to initiate, at the beginning of an image field, the transfer of image information from the imaging device to the video signal processing circuits.
In one preferred embodiment of the invention, the timing generator includes means for supplying video timing signals to the video processing circuits and the reset means is adapted to interrupt and restart the video timing signals simultaneous with the image transfer clocking means to maintain synchronism between the two. In another preferred embodiment of the invention, the reset means includes means responsive to a field timing signal to synchronize restarting of the image transfer clocking means with the beginning of a desired field interval following conclusion of the flash illumination.
BRIEF DESCRIPTION OF DRAWINGS
In the drawings:
FIG. 1 is a block diagram of one preferred embodiment of an image recording system constructed in accordance with the present invention.
FIG. 2 is a timing diagram of signal conditions for the system of FIG. 1.
FIG. 3 is a block diagram of a portion of the system of FIG. 1 illustrating another preferred embodiment of the present invention.
FIG. 4 is a timing diagram signal of conditions for a signal recording system of FIG. 1 when modified as shown by the block diagram of FIG. 3.
DETAILED DESCRIPTION
Referring to FIG. 1, the illustrated image recording system includes a photographic film camera 10 and a video camera 12. A beamsplitter 14 is situated to direct light reflected from a subject 16 simultaneously to film camera 10 and video camera 12. Alternatively, beamsplitter 14 may be omitted and cameras 10 and 12 aimed directly at the subject 16. Film camera 10 is conventionally provided with a "PC" output terminal 18 for supplying a flash request electrical signal which is asserted when the film gate in the camera is completely opened and is deasserted when the film gate begins to close. The flash request signal from terminal 18 is conventionally applied via line 20 to flash apparatus 22 to initiate flash illumination on subject 16.
The video camera 12 includes an imaging lens 24 which focuses an image of subject 16 onto a solid state CCD imaging sensor 26 for capturing the video image of the subject 16. A video camera timing generator 28 includes conventional image transfer clocking means adapted to provide, in known manner, image transfer processing signals V, H and XSG via a clock driver circuit 27 to sensor 26 to control the timing at which sequential lines of image pixel data are transferred out of sensor 26 to video signal processing circuits 30. The details of this operation are well known in the art with the process of transferring image data out of sensor 26 being described in the above mentioned U.S. Pat. No. 4,805,037, the disclosure of which is incorporated herein by reference.
Timing generator 28 also provides timing signals to video signal processor 30 which operates in known manner to generate a composite video signal comprised of successive fields of video image signals derived from the image pixel data from sensor 26 and separated by vertical blanking intervals. The composite video signal output from the video processor 30 is furnished to image store apparatus 32 to store the video image signal, for example on still video floppy disks, for subsequent display on a video display monitor 34. As is well known, and depending on the nature of the video processing circuits employed, the video image signal may be stored as a non-interlaced image frame or, more typically, for NTSC type video signals, as a full frame of two successive interlaced image fields. In the latter case, either a single field of video information may be displayed with some loss of vertical resolution or, more preferably, a full frame of two successive interlaced fields is displayed for full resolution.
In accordance with a particular feature of the invention, the flash request signal from output terminal 18 of film camera 10 is also coupled to a one shot multivibrator circuit 36 in video camera 12 to generate a reset signal which is applied to clock generator circuit 28 and also to image store apparatus 32. One shot circuit 36 comprises reset means responsive to the flash request signal for interrupting operation of the clock generator circuit 28 at the beginning of a flash illumination by flash apparatus 22 and further serves according to the invention to restart the clock generator circuit 34 following conclusion of the flash illumination to initiate the transfer of image information from the image sensor 26 to the video processing circuits 30. The restarting of the image transfer process at the conclusion of the reset period is adapted so that regardless of when the image transfer process was interrupted at the beginning of reset, as a consequence of a randomly generated PC flash request, the process of image transfer out of image sensor 26 starts anew at the beginning of an image field. In this fashion, the flash illumination is assured of being evenly distributed across a full frame of video image signal, either two successive fields of interlace video or a single frame of non-interlace video.
This is best illustrated in the timing diagram of FIG. 2 wherein a PC flash request signal 40 is asserted at an arbitrary time following the occurrence of a vertical blanking pulse 42 generated in timing generator 28. The assertion of PC signal 40 causes one shot circuit 36 to generate a reset signal 44 of a predetermined duration preferably chosen to be at least equal to the maximum duration of the flash illumination by flash apparatus 22. In the system of FIG. 1, a reset duration of 3 ms is chosen as being adequate for most professional studio strobe flash units, although other durations might also be preferred. When reset signal 44 is asserted, i.e. goes low at falling edge 44a, the operation of timing generator 28 is interrupted which, in turn, interrupts the image transfer process at image sensor 26 by momentarily disabling the clocking signals applied via clock driver 27. The video timing signals applied to video process 30 are also momentarily disabled. At the conclusion of the flash illumination, as represented by the rising edge of pulse 46, the reset signal 44 desserts, i.e. goes high at 44b, thus enabling timing generator 28 to reinitiate generation of the image transfer and video signal timing signals as represented by XSG signal 47 and vertical blanking signal 48. Coincident with this, image store apparatus is set to respond to the reset signal 44 supplied on line 49 represented by "grab frame" signal 49 to initiate storage of the ensuing frame of video image signal from processor 30.
It will be appreciated from FIG. 2 that interrupting the process of image transfer out of sensor 26 any time a flash is initiated and restarting with the beginning of an image field assures that the flash illumination will be properly and fully present on the image stored in apparatus 32. In the case of full frame storage (non-interlaced fields), the full flash illumination will be captured and stored. In the case of NTSC type video signals with interlaced fields, the flash will be evenly distributed across two successive video image fields stored in apparatus 32. One difficulty with the system of FIG. 1, however, is that the resetting of video synchronization, as represented by the truncated interval between vertical blanking signals 42 and 48, will result in a momentary loss of synchronization of the video image on display 34. This is not thought to be serious problem, however, since the monitor is able to resynchronize on the new video timing in a matter of only one or two seconds.
In FIG. 3, a modification of the reset means is shown which obviates the problem of synchronization loss. In the modification of FIG. 3, the output of the one shot 36, rather than being applied directly to video timing generator 28', is coupled to one input terminal of a bistable flip-flop circuit 50. A field timing pulse, preferably the "field one" pulse, from timing generator 28 is applied to the other input terminal of flip-flop 50. The set output side of flip-flop 50 corresponding to the "field one" input is then used as the reset signal applied to the video timing generator 28' and image store apparatus 32. The operation of timing generator 28' in response to the reset signal from flip-flop 50 is similar to that of generator 28 in FIG. 1 except that only the image transfer clocking signals are interrupted by the reset signal in the system of FIG. 3. The video timing signals sent to video processor 30 are not affected. The effect of this can be seen with reference to the timing diagram of FIG. 4. Thus the random arrival of a PC flash request signal 40 generates an intermediate one shot pulse 41 applied to the R input terminal of flip-flop 50 causing the "1" output side to fall at 44a of the modified reset signal 44'. A flash illumination is simultaneously generated as represented by pulse 46. As long as the reset signal 44' is low, the image transfer process at sensor 26 is interrupted or suppressed as represented by the absence of an XSG pulse 47' shown in dotted outline below vertical blanking signal 56. Unlike the reset signal 44 of FIG. 2 which lasts for onlY the fixed 3 ms duration established by one shot circuit 36, the modified reset signal 44' of FIG. 4 is extended until the occurrence of the next "field one" pulse from timing generator 28'. The "field one" pulse is applied to the S terminal of flip 50 to set the "1" output side of flip-flop 50 high at 44b thus enabling XSG pulse 47 to reinitiate the image transfer process at the beginning of an image field and generating a Grab Frame pulse to initiate image storage in apparatus 32. As a consequence of this arrangement, the timing of vertical blanking (and other video timing signals) is uninterrupted and there is no disruption of the video sync at the display monitor. It will be appreciated that either field pulse may be used to terminate the reset signal 44' and that the frame pulse in a full frame, non-interlace video system may also be used. As used in the appended claims, the term field timing pulse is intended to refer either to an interlace field timing pulse or to a frame timing pulse of a non-interlace video system.
The invention has been described in detail with particular reference to a presently preferred embodiment, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.
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A system for simultaneous recording of a flash image on photographic film and video cameras in which flash operation during the process of image transfer out of an image sensor in the video camera is avoided by means of a simple synchronizing circuit. The synchronizing circuit operates in response to a flash request signal from the film camera to interrupt the transfer of image information out of the image sensor in the video camera for at least the duration of the flash illumination on the subject. Following conclusion of the flash illumination, the synchronizing circuit resets the image sensor processing circuits to restart transfer of the image information out of the image sensor at the beginning of an image field. The restart can coincide with conclusion of the flash illumination or can be delayed to coincide with a desired video frame in the composite video signal.
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BRIEF SUMMARY OF THE INVENTION
This invention relates to a building wall adapted to be erected with blocks that are pregrooved on the inner and outer faces and ends to form a matrix of grooves to receive a surface overcoat into which a variety of designs can be impressed or indented, and it also relates to a method of developing many designs in a surface coating for one or more surfaces of walls using grooved surfaces in underlying blocks.
The prior art is known to have a concrete or masonry block wall capable of being manufactured with surface designs. However, normally the wall blocks do not come with any pattern of grooves so that the grooving has to occur after the blocks are laid up in a wall. A special situation is known where concrete masonry blocks formed in apparatus of U.S. Pat. No. 3,381,345 of Charles L. Williams offer limited possibilities for surface decoration, as these blocks are sized and shaped only to simulate the appearance of standard brick wall lay ups. It is also known in the art that designers and architects like to call for esthetic characteristics in a lay up of blocks in a wall such that they form designs in or on the wall surface or designs with raised surfaces on two or more blocks which is repeated throughout the wall. Generally it requires several blocks to be matched to complete one design which is repetitive. These prior art examples are expensive and require many different blocks to complete a wall design. Great care is required to properly match blocks which takes time and increases costs and requires large inventories of blocks for each design. Each block design also requires its own mold parts, so an inventory of molds is required.
It is also known that an architect or designer will seldom use a design more than one time, and it is very unlikely that his competitors will use the same design or pattern. Therefore, special designed masonry units are very costly.
The objects of the present invention are to provide a modular matrix of grooves carried as a standard throughout many different sizes of molded concrete blocks so that a wall lay up with any one block size or even several sizes of blocks can have the matrix of grooves match up to form the basis for receiving a coating of suitable material capable of being impressed or indented in a variety of designs drawn out of the underlying matrix of grooves, to provide a coating for the surfaces of a building wall that can receive a design while it is in a workable state and hold a design thereafter, where the design or designs may be composed of lines selected from corresponding underlying grooves in the wall blocks, to provide a method of achieving ornamental designs in a masonry wall or walls with the use of simple well known jointer tools, and to provide architects with a generally common system of grooved blocks to quickly and economically choose different designs and form selected designs in one or all of the walls of a building or vary the designs for each wall of a building after the wall is laid up.
The invention is embodied in a decorative building wall, whether an internal partitioning wall or an exterior wall, which comprises in combination a plurality of blocks laid up in cooperative abutting relation in courses to form a wall surface, a plurality of grooves formed in each block with the grooves providing a matrix in the lay up of the wall, and a layer of a settable material covering the grooved matrix in which is impressed a pattern of grooves, following one or more of the grooves in the matrix whereby the surface of the wall formed by the blocks takes on a decorative appearance.
The invention is further embodied in a method of decorating the surface of an otherwise raw building wall, whether an interior partition or an exterior wall, composed of blocks arranged in abutting relation in courses to form a wall surface, which method consists in grooving the surfaces of the individual blocks, laying the blocks in abutment in the wall with the grooves exposed in cooperative adjacency to form a matrix of grooves and joints, covering the matrix with a coating of settable material, and impressing the coating material prior to setting with a decorative pattern of visible grooves which overlie one or more of the grooves in the covered matrix.
BRIEF DESCRIPTION OF THE DRAWINGS
This invention is embodied in certain forms of molded blocks with a selection of grooves forming a matrix in a wall lay up, and is represented in the accompanying drawings, wherein:
FIG. 1 is a perspective view of a typical block having a 4 inch thickness carrying a pattern of side and end grooves, the pattern on the visible end being duplicated in the hidden surfaces when necessary;
FIG. 2 is a perspective view of a typical 6 inch thick block carrying a pattern of grooves in the visible end and side, it being sometimes necessary to form similar grooves in the hidden surfaces;
FIG. 3 is a perspective view of a typical 8 inch thick block formed with a pattern of grooves in the end and sides, and when necessary with grooves in the hidden surfaces;
FIG. 4 is a perspective view of a typical 10 inch block having the pattern of grooves like those in the block of FIG. 2, and when necessary in the hidden surfaces;
FIG. 5 is a perspective view of a 12 inch thick block having the grooves compatible with those of the other blocks, and when necessary in the hidden surfaces;
FIGS. 6, 7 and 8 are perspective views of fragmentary wall lay ups using 8 inch thick blocks of FIG. 3, and showing the varieties of designs that can be impressed or indented in the coating applied to the wall; and
FIG. 9 is a fragmentary sectional view taken along line 9--9 in FIG. 6 to show a typical detail of the coating applied to the surfaces of blocks of FIG. 3.
DETAILED DESCRIPTION OF THE EMBODIMENTS
The molded concrete block 10 in FIG. 1 has a generally rectangular body with opposite vertical ends 11, opposite vertical faces 13 and top and bottom surfaces 14 and 15. The body is formed with cored openings 16 to reduce weight. The visible end 11 and face 13 are formed with aligned grooves 17, 18 and 19 and the face 13 is formed with parallel vertical grooves 20, 21 and 22. It is preferred to form block 10 with certain dimensions that have become standard in the concrete block industry. Therefore, block 10 is formed to be about 4 inches wide, about 8 inches high, and about 16 inches long. These dimension are then used to determine where to place the several horizontal grooves and the vertical grooves.
For example, if the block 10 is to be compatible with the standard brick, which is 21/4 inches, by 35/8 inches, by 75/8 inches, the groove 18 is located to divide the 8 inch height equally. The grooves 17 and 19 are then located in spaced relation from groove 18 to divide the 8 inch height into three equal parts. The vertical set of grooves 20, 2l and 22 (FIG. 1) are located to divide the length of 16 inches into quarters, or divisions of about 4 inches each. Obviously due allowance needs to be made for mortar joints, but for the simplicity of this disclosure the foregoing general arrangement of the horizontal set of grooves 17, 18, 19 in the ends as well as the sides will be followed throughout the other blocks.
If a wall is laid up using only the blocks of FIG. 1, the running bond between the first and second courses (FIG. 9) would be on a one quarter bond in which one space between the vertical groove 22 and the nearest end 11 would lap on the adjacent underlying block. This bond pattern is dictated by the way the blocks in a corner are overlapped. It is clear that the grooves 17, 18 and 19 and the grooves 20, 21 and 22 form a matrix of horizontal and vertical grooves out of which can be selected an infinite variety of designs from a design of a standard brick lay up to wide horizontal bands or vertical column effects.
Having now visualized the possible designs that can be selected, it is the next step of this invention to mask the entire matrix of grooves in a complete wall with a settable coating. The coating can be made up from a cement base with fine sand or crushed limestone, a bonding agent such as ACRYL 60 by Standard Dry Wall of Florida, and suitable waterproofing agents. Coloring can be mixed into the coating, or paint can be applied later. The coating can be laid on in any approved manner and has a thickness which may vary from about one-sixteenth to about three-sixteenth inch so as to completely cover all grooves and joints. It is preferred to rely upon the thinner coating for ease of tooling and following the underlying grooves. Before the coating sets up or hardens, the wall is tooled with a mason's jointer tool in the vertical and horizontal groove locations previously chosen. As the tooling progresses the selected design will emerge and give the wall a pleasing appearance. In this manner, a raw concrete block wall usually having the blocks boldly outlined in rectangles of 8 inches by 16 inches can be transformed into one that is made to look like a brick wall without actually having an underlying brick wall. Examples of generally standard designs for a raw uncoated wall are Coursed Ashlar, Vertical Stacking, Horizontal Stacking, Square Stacking, Basket Weave, and Patterned Ashlar. A coated wall with an underlying groove matrix is unique as patterns can be brought out in which the coating is indented with the pointing tool to build the selected design. It is important to allow the mortar used to hold the blocks in the wall to set up and become rigid so that the impressing of the design will not disturb the lay up. In creating a design, the tooling must progress right along with the application of the coating so the grooves can be followed.
In FIG. 2 there is shown a 6 inch wide block 23 formed with cored out openings 24 to reduce weight. This block is formed with a series of vertical and horizontal grooves on its 16 inch long face 25 which exactly duplicate the grooves in the face 13 of block 10, and these grooves have similar reference numbers. The pattern of grooves in the visible end 26 includes the continuation of the three horizontal grooves 17, 18 and 19 from face 25. The end 26 which is 6 inches wide is formed with a pair of vertical grooves 27 and 28 which are spaced from the corners of the block body so that groove 27 is spaced from the farthest corner 29 a distance equal to about the width of block 10. The other groove 28 is spaced a similar distance from the farthest corner 30 so as to maintain modular compatibility with block 10.
In like manner, the block 31 of FIG. 4 is formed on its face 32 with a pattern of horizontal grooves 17, 18 and 10 described before, and with a pattern of vertical grooves 20, 21 and 22 as before noted. The block 31 is cored out at 33 to reduce weight. Carrying out the modular pattern of the vertical grooves 27 and 28 in the end of block 23, it is now evident to have four such grooves in the end of block 31 and these are designated 27, 28, 27A and 28A.
The block 35 of FIG. 3 is the most widely used size, being about 8 inches wide and high and about 16 inches long. Cores 36 are formed to reduce weight. The pattern of grooves in the side face 37 are the same as for block 10 and are so designated by similar reference numbers. The end 38 is about 8 inches wide and, therefore, lends itself to be divided by a single vertical groove 39 into about 4 inch halves.
The remaining block 40 shown in FIG. 5 is 12 inches wide and is formed with cores 41 to reduce weight. Again, the side face 42 is formed with the now familar pattern of horizontal grooves 17, 18 and 19, and with the equally spaced vertical grooves 20, 21 and 22. The grooves in the end 43 include vertical grooves 44 and 45 which are spaced to divide the end into about 4 inch equal divisions. The spacing of grooves 44 and 45 is about the same as for the spacing of grooves 20, 21 and 22 in the side to maintain the modular dimensions.
Turning now to FIG. 6, it can be seen that the wall lay up is composed of the blocks seen in FIG. 3, and the wall includes a corner and two wall runs leading away from the corner. This perspective view illustrates the steps of the method of transforming the raw surface of a block wall into a wall having a pleasing appearance. The raw wall lay up of blocks 35 can be seen at the left so that the matrix of grooves 17, 18, 19, 20, 21 and 22 match up in a running bond with mortar joints 46 outlining the respective blocks. After the blocks 35 are laid up, a parget or coating 47 is applied over the blocks 35 so the several grooves are covered and the coating penetrates the grooves. FIG. 9 is a fragmentary section to show the coating 47 covering grooves 21, 22 and a mortar joint 46 between adjacent blocks 35. The grooves and joint 46 are raked or rectangular so the coating 47 will penetrate the same and preserve the integrity of the coating layer when tooling in the design. One example is to form the groove about 3/4 inch wide and 3/16 inch deep, and to apply the coating 47 to a depth of from about 1/16 inch to about 3/16 inch. The coating extends to the left from the corner and the area covered is about as large as is desirable for the purpose of allowing the worker to pick up the desired underlying grooves from those exposed ahead (to the left) of the application of the coating. The wall area to the right of the corner has a complete columnar design impressed therein by indentations 48.
The views of FIGS. 7 and 8 provide other examples of designs impressed in the coating 47 applied over a wall composed of blocks 35 having mortar joints 46. In the design of FIG. 7 the vertical indentations 48 are now blended into adjacent horizontal impressions 49 and by broken or discontinuous horizontals 50. The coating 47 is laid on and the design follows up closely behind the progressive laying on the coating. The view of FIG. 8 shows still another wall design which is a variant of the design of FIG. 7 but having smaller areas defined by the indentations. Thus the vertical indentations 48 are further blended into evenly spaced horizontal indentations 51, and by a combination of short vertical indentations 52 and cooperating horizontal indentations 53.
The blocks seen in FIGS. 1 to 5 can be commercially produced in known manner by providing the forming molds with vertical ribs or inserts which form the grooves 20, 21, 22, 27, 28, 27A, 28A, 39, 44 and 45 and allow the blocks to be ejected onto a conveyor. The blocks are then aligned and passed adjacent gang masonry saws or grooving discs and the respective grooves 17, 18 and 19 are formed in two passes, one for the sides and one for the ends.
As can be seen in FIG. 3, the block 35 is formed in the cored passages 36 with notches 55 extending through the heighth of the block, and with a central slot 56 in the body web between cored openings 36. The notches are supplied to make it easy to break off a portion of the block body so the reduced portion will fit a need for less than a complete or whole block. The slot 56 serves the same function when a one-half block is needed. The other blocks seen in FIGS. 1, 2, 4 and 5 may be similarly provided with notches and slots but these are not thought necessary to show as it can be readily appreciated from FIG. 3.
It can now be understood that a building wall laid up with blocks of the character described, having a resulting matrix of cooperating grooves in one or both surfaces, can be coated or pargetted with a settable material and impressed or indented with any of many designs or with a combination of designs overlying and guided as to location by the underlying grooves in the blocks. The resulting wall construction with a decorative surface design different from the regular running bond mortar joint scheme can be created by the unique method of selecting a pattern of guiding grooves from the wall block groove matrix, coating the blocks, and tooling the selected design into the coating. Where the blocks are used to form interior walls between adjacent spaces or areas, the unique method can be used to great advantage to impress a different design on the opposite surface of the common wall. Since it has been pointed out before that the blocks can be grooved on opposite ends or sides, it follows that a common wall, such as a partition separating adjoining spaces, can be made up of blocks having the same matrix of grooves on the opposite exposed faces and the decorative designs of FIGS. 6, 7 or 8 may be impressed in the opposite walls so that the monotony of repetitive designs is easily avoided.
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A building wall erected from blocks presenting one or more surfaces formed with a matrix of grooves generally horizontally and vertically related, and an overlay veneer or applied surface coating adapted to be impressed or indented with appropriate tools in a manner to produce a wide variety of designs by selection of different combination of the grooves in the matrix. A method of variously decorating one or more building wall surfaces or sides of walls with the guidance of a matrix of grooves and an overlay coating adapted to be impressed or indented in cooperation with preselected grooves of the matrix.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to French Patent Application No. 1462081 filed Dec. 8, 2014, the disclosure of which is hereby incorporated in its entirety by reference.
[0002] 1. Field of the Invention
[0003] This invention pertains to an iron comprising a body and a metal soleplate that is folded back against the body, the soleplate comprising a lower surface defining an ironing surface and having, at least locally, a folded-up edge that defines a peripheral edge of said ironing surface, and pertains more specifically to an iron in which the folded-up edge of the soleplate comes into contact with the body in order to help attach the soleplate to the body.
[0004] 2. Description of Related Art
[0005] There exists, in patent application EP 0 682 724 filed by the applicant, an iron comprising a soleplate, or cap, which is folded back against a heating body, the soleplate comprising a lower surface defining an ironing surface and comprising a folded-up edge defining a peripheral edge of the ironing surface. In this patent, the soleplate is attached mechanically against the body by bringing the folded-up edge into contact with the body.
[0006] Such a solution offers the advantage of providing a simple, inexpensive mechanical means of attaching the soleplate onto the heating body, as this mechanical attachment alone can attach the soleplate onto the body or supplement a layer of glue used to attach the soleplate to the body.
[0007] However, such a peripheral edge gripping the heating body presents the disadvantage of being relatively thick, which makes it difficult to iron around clothing buttons. Moreover, the significant thickness of such a peripheral edge also detracts from the visual appearance of the iron.
[0008] Consequently, the purpose of this invention is to provide a steam iron comprising an ironing bottom that is attached in a simple, inexpensive manner to the body of the iron, and that has a peripheral edge that is not very thick. Another purpose of the invention is to provide an iron in which the soleplate attachment offers complete freedom in the positioning of steam release holes in the soleplate.
SUMMARY OF THE INVENTION
[0009] To this end, the object of the invention is an iron comprising a body and a metal soleplate that is folded back against the body, the soleplate comprising a lower surface defining an ironing surface and comprising, at least locally, a peripheral edge, where the soleplate is folded up in the direction of the body and comes into contact with said body to help attach the soleplate to the body, characterized in that the peripheral edge comprises a portion that is folded 180° at the place where the soleplate extends parallel to the ironing surface, and in that the portion folded 180° is extended by a latch part that comes into contact with the body.
[0010] Such a characteristic makes it possible to obtain an iron in which the peripheral edge of the ironing surface is flat and thus not very thick, which makes ironing around clothing buttons easier.
[0011] In another characteristic of the invention, the peripheral edge of the ironing surface is of a thickness that is roughly equal to, or less than, twice the thickness of the soleplate.
[0012] In another characteristic of the invention, the latch part comprises, successively, starting from the portion folded 180°, an intermediate portion that is folded upward, and then a free end that is pressed down against the body to attach the soleplate to the body.
[0013] Such an attachment of the soleplate by the latch parts located at the periphery of the soleplate offers the advantage of being simple and inexpensive to implement. Moreover, this attachment is independent of the positioning of the steam release holes on the soleplate, such that the distribution of steam release holes on the soleplate can be modified without impacting the soleplate attachment.
[0014] In another characteristic of the invention, the intermediate portion extends perpendicular to the ironing surface.
[0015] In another characteristic of the invention, the free end of the latch part is aligned with the intermediate portion when the soleplate is set in place on the body, and then mechanically pressed down against the body to attach the soleplate.
[0016] In another characteristic of the invention, the ironing surface and the peripheral edge of the soleplate are covered with a coating, such as enamel.
[0017] Such a coating makes it possible to improve the mechanical characteristics of the ironing surface, and specifically how it slides and/or resists scratching.
[0018] In another advantageous characteristic of the invention, the latch part is not covered with the coating.
[0019] Such a characteristic prevents the coating from cracking when the latch part is folded.
[0020] In another characteristic of the invention, the latch part is covered with the coating at the same time as the peripheral edge and the ironing surface of the soleplate.
[0021] Such a characteristic simplifies the coating application process, as the coating can be applied without having to mask the latch parts.
[0022] In another characteristic of the invention, the soleplate is made of aluminum.
[0023] Such an aluminum soleplate offers the advantage of being easy to manufacture and of transferring heat well.
[0024] In another characteristic of the invention, the thickness of the soleplate is between 0.8 mm and 1.5 mm.
[0025] In another characteristic of the invention, the body is a heating body that contains an electrical resistor.
[0026] The purposes, aspects and advantages of this invention will be better understood through the description provided below of one particular method of implementing the invention, as well as one variation of implementation, presented as non-limiting examples, in reference to the attached drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] FIGS. 1 and 2 are exploded perspective views of an iron bottom set in one particular method of implementing the invention, the bottom set comprising a soleplate and a heating body;
[0028] FIG. 3 is a perspective view of the iron bottom set in FIG. 1 , with the heating body and the soleplate assembled;
[0029] FIG. 4 is a view from above of the iron bottom set in FIG. 3 ;
[0030] FIG. 5 is a cross-section view along Line V-V in FIG. 4 ;
[0031] FIG. 6 is a cross-section view, similar to FIG. 5 , before folding the latch part against the heating body;
[0032] FIG. 7 is a view from above of the soleplate before folding; and
[0033] FIG. 8 depicts a detailed view, in a transverse cross-section, of a bottom set according to one variation of implementing the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0034] FIG. 1 shows an iron bottom set situated traditionally below a container of water, not depicted in the drawings, this set comprising a metal soleplate ( 1 ) and a heating body ( 2 ) designed to be folded back onto the soleplate ( 1 ).
[0035] The heating body ( 2 ) advantageously consists of an aluminum casting comprising an electrical resistor ( 20 ) bent into a horseshoe shape, as well as an indentation ( 21 ) arranged to house a temperature-regulating thermostat.
[0036] The heating body ( 2 ) comprises, in its upper portion, a steam chamber ( 22 ) designed to be closed by a closure plate, not depicted in the drawings.
[0037] The water in the iron's container is brought, in a self-evident manner, by a drip mechanism, into the steam chamber ( 22 ), and the steam thus generated is distributed by a peripheral channel ( 23 ) extending around the steam chamber, on the upper surface of the heating body ( 2 ).
[0038] As shown in FIGS. 2 through 4 , the channel ( 23 ) has holes ( 24 ) through the heating body ( 2 ) and leading into a steam distribution chamber ( 25 ) extending on the lower surface of the heating body ( 2 ), the distribution chamber ( 25 ) supplying a network of steam release holes ( 10 ) in the soleplate ( 1 ).
[0039] The soleplate ( 1 ) comprises a flat lower surface that defines an ironing surface, comprising an area equipped with steam release holes ( 10 ), that extends through the network of steam release holes, and at which place the upper surface of the soleplate ( 1 ) comes into contact with the surfaces of the heating body ( 2 ) so as to ensure proper heat transfer from the heating body ( 2 ) to the soleplate ( 1 ), an airtight seal being arranged at the periphery of the heating body ( 2 ) to ensure a seal that is airtight against the steam between the soleplate ( 1 ) and the heating body ( 2 ).
[0040] As shown in FIGS. 5 and 6 , the soleplate ( 1 ) comprises a peripheral edge ( 11 ) that defines the perimeter of the ironing surface, the peripheral edge comprising a portion ( 12 ) that is folded 180°, obtained by successively folding the soleplate ( 1 ) upward, and then toward the interior of the ironing surface, and by pressing it down against the upper surface of the soleplate ( 1 ).
[0041] The soleplate ( 1 ) comprises, locally, in the extension of the portion ( 12 ) that is folded 180°, latch parts ( 13 ) comprising an intermediate portion ( 13 A) directed upward to form a 90° bend with the folded-up portion, said intermediate portion ( 13 A) being extended by a free end ( 13 B) that extends vertically upward, such that the heating body ( 2 ) can be inserted between the latch parts ( 13 ) and applied against the soleplate ( 1 ) during the iron assembly process.
[0042] Such a free end ( 13 B) is then pressed down horizontally on the edge of the heating body ( 2 ), such that the latch parts ( 13 ) exert pressure on the heating body ( 2 ), which holds the soleplate ( 1 ) in contact with the heating body ( 2 ).
[0043] As shown in FIG. 1 , these latch parts ( 13 ) are advantageously distributed along the periphery of the heating body ( 2 ), the soleplate ( 1 ) comprising, in the example illustrated in the drawings, two lateral latch parts ( 13 ) consisting of flaps extending from each side of the soleplate ( 1 ) from one pointed forward end of the soleplate ( 1 ), over roughly two-thirds the length of the soleplate ( 1 ), and a back latch part ( 13 ) consisting of a flap extending to the back end of the soleplate ( 1 ), the heating body ( 2 ) advantageously comprising, at the height of these latch parts ( 13 ), a flat peripheral edge with a casing ( 26 ), shown in FIG. 1 , that is adapted to receive the latch part ( 13 ).
[0044] The soleplate ( 1 ) may also advantageously comprise guide parts ( 14 ) consisting of divider flaps that remain oriented vertically and that cooperate with the edge of the heating body ( 2 ) to laterally guide the soleplate ( 1 ) with respect to the heating body ( 2 ).
[0045] FIG. 7 depicts, as an example, the shape of the soleplate ( 1 ) prior to folding, said soleplate ( 1 ) being obtained by cutting an aluminum sheet that is between 0.8 mm and 1.5 mm thick. This soleplate ( 1 ) then undergoes a first folding step, in which the latch parts ( 13 ) and the guide parts ( 14 ) are folded 90°, and then a second folding step in which the soleplate ( 1 ) is folded 180° along the perimeter of the ironing surface, illustrated by a dotted line in FIG. 7 , in order to obtain a soleplate as illustrated in FIG. 1 , in which the peripheral edge ( 11 ) of the ironing surface has a thickness that is roughly equal to twice the thickness of the soleplate ( 1 ).
[0046] Preferably, the soleplate ( 1 ) thus made, is partially coated in enamel prior to its assembly with the heating body ( 2 ), as the enamel-coated surface can be limited to the ironing surface and to the peripheral edge ( 11 ) of the soleplate ( 1 ), while the latch parts ( 13 ) can remain in the as-cast state, which is to say not coated in enamel, in order to prevent cracks from forming in the enamel when the latch parts ( 13 ) are folded.
[0047] However, in one variation of implementing the invention, the latch parts ( 13 ) may also be coated in enamel at the same time as the ironing surface, in order to simplify the coating application process. Indeed, the latch parts ( 13 ) offer the advantage of being hidden by the casing of the iron when the heating body ( 2 ) is assembled to the iron, such that any cracks forming in the coating of the latch parts will not be visible to the user.
[0048] The bottom set thus made offers the advantage of being simple and inexpensive to produce, the soleplate offering the advantage of being mechanically connected to the heating body by a simple process of folding the latch parts.
[0049] Moreover, the iron equipped with such a bottom set offers the advantage of possessing a soleplate with a flat peripheral edge that is not very thick, allowing for easy ironing around clothing buttons.
[0050] FIG. 8 depicts one variation of implementing the bottom set illustrated in the previous drawings, in which the soleplate ( 1 ) comprises one or more steam release holes ( 10 A) arranged immediately alongside the peripheral edge ( 11 ) of the soleplate ( 1 ), and advantageously near the front point of the soleplate ( 1 ).
[0051] In this variation of implementation, the soleplate ( 1 ) advantageously comprises a smaller thickness at the periphery of the ironing surface, in order to promote the diffusion of steam toward the external edge of the ironing surface.
[0052] Such an ironing variation offers the advantage of comprising steam release holes at the periphery of the ironing surface for greater efficacy when ironing difficult-to-reach corners of clothes, such as the curves of buttons or shirt collars.
[0053] Of course, the invention is in no way limited to the methods of implementation described and illustrated, which are provided only as examples. Modifications remain possible, particularly with respect to the constitution of the various components or by substituting equivalent techniques, while still remaining within the scope of protection of the invention.
[0054] Thus, in one variation of implementing the invention that is not depicted, the latch parts may cover the entire perimeter of the heating body or be located only in several places distributed along the periphery of the heating body.
[0055] Thus, in one variation of implementing the invention that is not depicted, the soleplate may be made of stainless steel.
[0056] Thus, in one variation of implementing the invention that is not depicted, the soleplate may be coated with an inorganic polymer-type coating applied using a sol-gel process.
[0057] Thus, in one variation of implementing the invention that is not depicted, the body onto which the soleplate is attached may not be a heating body.
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Iron including a body ( 2 ) and a metal soleplate ( 1 ) that is folded back against the body ( 2 ), the soleplate including a lower surface defining an ironing surface and including, at least locally, a peripheral edge ( 11 ) where the soleplate is folded up in the direction of the body ( 2 ) and comes into contact with the latter to help attach the soleplate ( 1 ) to the body, wherein the peripheral edge ( 11 ) includes a portion ( 12 ) that is folded 180° at the place where the soleplate ( 1 ) extends parallel to the ironing surface, and in that the portion ( 12 ) that is folded 180° is extended by a latch part ( 13 ) that comes into contact with the body ( 2 ).
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BACKGROUND OF THE INVENTION
Certain diseases and conditions, such as old age, chronic or major diseases, accidents, surgeries, etc., often cause a serious mobility problem for a person. They can bring about their own major complications, such as ulcerations and bedsores, etc., especially when a person cannot move and stays in the bed, mostly in one position. In these circumstances, the pressure on the skin area, constantly pressed by the adjacent bones (mostly joints) from one side and by the surface of the mattress from the other, will cause gradual deterioration of the nutrition of the skin and underlying tissues, and ultimately ulcerations in that spot. Unfortunately, they are usually bad and very hard to treat, when the cause cannot be cured or eliminated. Ulceration does occur in any place where the skin is pressed against a hard surface, but is specially common in the lower back over the spine, in the ankles, in the heels, and sometimes in the knee area and side of the legs, back of the head, and again in any spots of skin over the bone that for one reason or another are pressed against a surface for a long time. The treatment is not easy as long as the cause cannot be eliminated and the pressure to the area continues to occur.
Observation of such patients during my career as a doctor made me think and finally offer a technique for supporting these areas and sores as well as for preventing damage to the areas. To my knowledge, this is new and genuine, and I believe it will work most of the time if used properly. It will also allow local treatment to be provided without a need for opening the whole unit. The technique, with some modification, can also be very helpful after many surgeries, as well as supporting the neck of a patient.
BRIEF EXPLANATION OF THE INVENTION
This invention is primarily related to making units from a piece of balloon that can be permanently or temporarily inflated to maintain air inside it. This balloon has a rather flat surface covered by a layer or layers of soft material, such as soft, non-irritant, thick fabric with fluffy surface, or a lambskin and/or soft plastic bubbles. This unit is made either from one balloon or preferably combinations of multiple balloons that absorb pressure and stay in place appropriately. The main balloon may be divided by walls to make compartment of balloons that will serve this purpose. This basic unit is shaped in different ways to construct other units that are used for protection of the back, ankles, elbows, neck, etc. In these cases, the units are shaped to go around the place desired to be used and joint(s) and the area which are intended to be protected. However, when the skin has ulceration in the area, then the unit has an opening or hole or empty protected space in the area over the ulceration so that the pressure on the ulcer spot is prevented. This unit is kept in place with the use of Velcro™ patches. Very importantly, the opening in the unit allows the skin care to be given when necessary, without a need to remove the whole unit. For example, the unit for the back allows the patient's skin to be cleaned and dressed with medications. Another unit goes around the neck and is held in proper position as required. Units that support and help in shaping operated sites are also mentioned in this application.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top view of a first embodiment.
FIG. 2 is a front view of FIG. 1.
FIG. 3 is a right end view of FIG. 2.
FIG. 4 is a top view of a second embodiment.
FIG. 5 is a front view of a third embodiment.
FIG. 6 is a front view of a fourth embodiment.
FIG. 7 is a top view illustrating a use position of FIG. 6.
FIG. 8 is a side view of the FIG. 7 embodiment in use.
FIGS. 9, 10, and 11 are right side, top, and left side views of a fifth embodiment in use.
FIGS. 12, 13, and 14 are left side, rear, and front views of a sixth embodiment in use.
FIGS. 15, 16, and 17 are left side, rear, and front views of a seventh embodiment in use.
FIGS. 18, 19, and 20 are left side, rear, and front views of an eighth embodiment in use.
FIGS. 21, 22, and 23 are front, left side, rear, and rear views of a ninth embodiment in use.
FIGS. 24 and 25 are top and side views of a part that is used with a preceding embodiment.
FIGS. 26 and 27 are front and right side views of a tenth embodiment in use.
FIGS. 28 and 29 are right side and front views of an eleventh embodiment in use.
FIG. 30 is a front view of a twelfth embodiment.
FIG. 31 is a top view of a balloon by itself.
FIG. 32 is a front view of FIG. 31.
FIG. 33 is a front view of a thirteenth embodiment containing balloons like those of FIGS. 31 and 32.
FIG. 34 is a front view of a fourteenth embodiment containing balloons like those of FIGS. 31 and 32.
FIG. 35 shows the embodiment of FIG. 34 in use.
FIG. 36 is a front view of a fifteenth embodiment containing balloons.
FIG. 37 is a top view of FIG. 36.
FIG. 38 is a cross section through a usage of the fifteenth embodiment.
FIGS. 39 and 40 are rear and side views of a sixteenth embodiment.
FIG. 41 is a view similar to FIG. 40 showing a different position for this embodiment.
FIG. 42 is an end view of the sixteenth embodiment.
DETAILED DESCRIPTION OF THE INVENTION
The invention generally involves specially shaped balloons to protect the areas and spots that are under pressure. A unit is made from balloons that can be permanently or temporarily inflated to maintain air or fluids inside. The fluid may be chosen with different consistency and different temperature. (When the fluid is used, an opening for air escape is added to the balloon.) This balloon has a rather flat surface on one side covered by a layer, or layers of soft material, such as soft, non-irritant, thick fabric with fluffy surface, or a lambskin and/or layer of soft plastic with a layer of soft bubbles under the soft cover. The main body of this unit is made either from one balloon, or preferably combinations of multiple balloons, that absorb the pressure, and have a shape and are supported to stay in the intended places appropriately. The main balloon can be divided by walls to make compartments of smaller balloons that will serve this purpose. A balloon which is divided into smaller balloons or is made from combinations of balloons may then have different ports of inflation to allow different groups of the balloons to be inflated either at different times or with different pressures or to give the important chance of inflating them periodically or alternatively.
The soft material covering the inner surface of this unit gives the skin a chance to enjoy a soft, cozy, and non-irritating surface of the unit while the outer surface, the thickness and shape of the unit prevent the surface of the mattress from touching it. I would like to indicate that unfortunately most mattresses, even some of the soft-covered beds, have not been an answer to this problem of bedsores, since they do not prevent the prominent parts of the body from touching the surface of the bed and standing on it for a long time, which is the unfavorable condition that occurs when the area is sore. The use of sponges has not been the answer either, since they are compressed and act like rough units themselves. My basic unit explained above is shaped to match the different anatomy of the areas with which it is intended to be used.
A matrix of plastic made from combinations of hard and soft plastic allows the shaping of my unit to be obtained and pieces of harder plastic help to avoid pressure of the balloons at certain important areas. It is intended to use this matrix to make a skeleton that may be needed in giving shape to the unit and having the shape of the balloons under control. Some pieces of this matrix may be like a thread going over the balloons to control their shape.
A plastic cover will be useful to protect the ulcer spots from pressure too. Since after the ulcer is healed, or in cases where the ulcer has not yet developed, a complete opening over the spot may not be truly necessary, and at this stage, if the prominent spot was only protected from the pressure, it should be sufficient. Therefore, for such uses, units are chosen that although the opening is not present, have a protective plastic piece that is used to prevent the unit from pressing on the point of sore or tender spot. Again, a screen of softer, non-stretchable plastics, or units like screens with desired shapes, is quite helpful in giving the shape to this unit.
These units are also very useful for treatment of injuries to the joints. In these cases, a unit can be chosen to immobilize the joint for the period for which it is required. For this purpose, the shapes that are made from one solid balloon combination will be more useful. Also, these are the cases for which use of fluid for filling the balloons will be more desirable, since it will give the chance of choosing the temperature, which can be very beneficial. For example, in early trauma where immobilization and the use of ice are recommended, the balloon may be filled with ice water to keep the area cold, and later, when heat is recommended to diminish the pain, warm water can be infused into the balloon. Also, if higher pressure were to be used to prevent spread of hematoma and swelling, then the pressure inside the balloon can be increased. These are all new possibilities with the use of one unit.
Alternatively, a support unit can be made from a soft but non-stretchable fabric that has a surface covered with patches of Velcro™. This unit allows sticking different sizes of balloons having a surface covered with matching patches of Velcro™. A combination will allow the balloons to be changed, and different balloons to be used when a balloon is popped or ruptured.
In order to further secure the shape and effectiveness of the unit, a cover of latex may be used and rolled or pulled to go over all of the unit in place. When functional, then the elasticity of this piece with its internal capacity of adapting the shapes will be very beneficial in helping to reach its overall purpose so that it will hold the whole unit in place and protect it. This elastic cover also gives the advantage that prevents dirt from going into the unit. An exchange is easily possible if needed. A model of this unit may also have a soft fortified rim in its ends so that it prevents water from reaching inside the unit, and this allows the areas above and below the unit to be washed without disturbing the covered area. The rim may be further fortified by having three parallel lines of round fortified latex lines to function like three parallel collars around the limb, and this will most probably prevent water from entering under the unit most of the time. The areas on the tip of joints are designed to have extra wall, like a wall of an accordion, that allows the wall to be functional when the joint is bent. This is very advantageous to prevent disfigurement of the unit when it is bent. This cover would make a distinct advantage in many cases. At the time of use, this cover can be pulled or rolled over the unit.
FIGS. 1-3 show a general embodiment of the invention. The base of the unit is a soft cover 1. The surface of the balloon is 2, the short inner walls of the balloon are 3, one small compartment of the balloon is 6, a soft Velcro™ piece 4 is at one end and a rough Velcro™ piece 5 is at the other end. The long walls are shown by dotted lines 8. One side of the balloon is 7.
FIG. 4 is very similar to FIG. 1, except this unit has a layer of soft plastic bubbles 9, which is on the base 10 of the big balloon. The spaces between the smaller bubbles, or balloons, are 11. FIG. 4 also shows an optional disposable inner liner 11A for placement in underlying relation to cover 1 so as to be between the person and cover 1 when the support is applied to the person.
FIG. 5 shows a unit that is made from a unit very similar to the one shown in FIG. 1, except this unit has an upper and a lower layer of soft balloon that are specially shaped so that this unit can work as a cervical collar as shown in FIG. 8. The center balloon is shown with its upper wall 24 and its lower wall 25, and it is divided by the long horizontal walls 8 and the shorter vertical walls 3 into compartments 6. The upper horizontal balloon 19 has a valley 20 in its upper rim for the lower chin/upper neck area. The lower horizontal balloon has valleys 22 and 23 to allow it to stand on top of the upper shoulders and a rise 21 that is to stand in the front of the lower neck/upper chest area. The upper balloon has an inflation port 17, and the lower balloon, an inflation port 18. One end has a soft Velcro™ piece 15 and the other end, a rough Velcro™ piece 16.
FIG. 6 is similar to the unit shown in FIG. 5, except this unit has protective pieces 30, 31, 32 of plastic in its wall to protect the sensitive areas of the neck from excessive pressure by balloons. The borders of these plastic walls are shown by dash and dot lines.
FIG. 7 is a view of a unit similar to the one shown in FIG. 6 that is curled to go around the neck of a person. The inner space where the neck will be placed is shown at 34, and the inner surface is shown at 1. A protective screen of plastic is shown by a heavy broken line 35 and has protective pieces of plastic 30, 31, 32 in its front area. Borders of the balloon are shown by dotted line 37, and the balloon's inner lumen by 36. The ends of this unit come together and are connected to each other by straps, one end of one of which is shown in the upper side of this Fig. at 15.
FIG. 8 shows a person using a unit similar to the one shown in FIG. 6. This figure shows the upper border to this unit, including valley 20, and the upper horizontal balloon 19. The middle large balloon divided by horizontal lines 8 and vertical lines 3 is shown in the center. The valley 22 is also shown, and the rear ends of this unit are held together by straps 40 and 41.
The cervical collar is made from a body of the balloons similar to one mentioned earlier that has been divided by internal walls to many compartments. This unit is covered by a soft comfortable lining as mentioned. This unit has a size and shape to wrap around and stand around the neck and to hold the neck in proper position. This unit is to be held in place by having the ends of the unit stick to each other and held in place with use of Velcro™ patches, or straps that will go from one side to stick to the other. The center piece has upper and lower balloons with the special shape shown in FIG. 5 and 6. This units to have their own independent inflation ports and are individually inflatable so that their size and relative shape can be changed and adjusted easily to match the shape of the neck of the user. These pieces have their own inflation port with related valves. These valves may have an automatic closure system so that they will close after the inflation bulb or the syringe is removed. The advantage of this unit is that in contrast to the readily available units, it will be lighter and importantly its shape is adjustable and the pressure inside can be controlled. The upper and lower balloons will make it possible for the unit to match the shape of the upper chest and the lower chin area of the person using it so that it would be more comfortable. This would be possible due to the fact that the balloon's shape will adjust and it will reshape and remodel to some degree, to give more room for the more pressured area and to fill the areas that have lesser pressure. While the body of the unit will maintain the desired shape for the whole unit. It will be possible to make the construction of the middle part more stiffer if it is desired. Alternatively, a colorful stiffer piece may be added to go around the middle balloons to make it more stiffer too. The inner part of the unit may have a piece of stiff plastic embedded under its lining in front of the great vessels of the neck and the trachea to prevent from the pressure to these sensitive parts. Also, a network or skeleton of plastic can be used to give shape and protection and body to the units when and as much as required. Pieces of synthetic foams may also be used in construction of this unit. This unit is to be used to support the neck of a patient and keep it in a medically desired position.
FIGS. 9-11 show a person's ankle that is wearing an ankle support made from a unit similar to the unit shown in FIG. 1. This unit has a matching shape that goes around the ankle and has one end sticking to the other in front with the use of Velcro™ patches. This unit has openings in front of the prominent points of the heel and the inner and outer sides of the ankle joints. The lower leg is 62, and the upper surface of the tip of the foot is 59. The lower piece of this unit, which is a balloon standing and covering the sole of the foot, is shown at 50. The outer surface of this piece is shown at 51, and the inner surface of this unit which has a soft cover is shown at 52. The upper rear side of this unit is shown at 53, and it has an outer surface shown at 54 and an inner surface shown at 63. The hole in front of the rear prominent point of heel 56 is shown at 55, and the opening of the wall in front of the prominent point of the outer ankle 58 is shown at 57. The front of this unit is in front of the foot and its edges are held together by the short straps 60 and 61 containing the Velcro™ patches. The outer surface of the inner side of the unit is shown at 66, and the opening in front of the prominent point 67 of the inner surface of the ankle is shown by broken line 65.
The unit for the ankle is made to have a shape to go around the ankle joint and to cover its rear surface and sides by an inflated balloon and to come and join together in the front by a fabric (which may have some elastic component in its construction to hold the unit together) with use of short straps or bands with pieces of Velcro™ patches on the surface of their ends. These openings 55, 57, 65 will give the unique chance that the sore and ulcer spots can be cleaned and dressed and medicated and even exposed to air and heat if desired without a need for removing the whole unit.
A matching patch of the soft balloon will be used to deliver medications. This patch of balloon will have a soft surface which may be covered with layers of gauze and medications that can be placed on the sore spot to provide the treatment. The thickness of this balloon can be chosen and will vary. This smaller balloon patch can be held in place by being taped on the surface of the unit. Alternatively, the main unit may have a strap that will go over and across the opening of the unit to be stuck to the other side of the unit. The tip of this strap will be held in place by having its end to stick to the side of the unit by a Velcro™ patch. When there are sores in the inner or outer prominent areas of the ankle, then a unit may be used with open spaces in front of those sore spots, again to allow the same advantages to be taken, with use of heating lamp cleaning, medicating, etc. Units will be made for the left and right ankles, having shapes where the unit to be used in left ankle is the mirror image of the unit for the right ankle. A universal unit may be made that can be used in each side. A disposable lining may be used under this unit which is explained more later in this application. Among lots of advantages this unit has, it may also prove to save a lot of time when it is used instead of bandaging the ankle in traumas, since it can be easily placed and stuck rather than having a need for skill and time of medical personnel to apply the wrap in the area.
FIGS. 12-14 show a person wearing a hip support made from a unit similar to the unit shown in FIG. 1. This unit has a matching shape that goes around the hip and buttocks and has one end sticking to the other in the front with the use of Velcro™ patches. This unit has openings in front of the prominent points of the hip joint. The trunk of the body is shown by 75 and the left thigh by 76. The balloon that is standing and protecting the buttock is shown by 79 and its outer surface by 78. The front of this unit is shown by 77, its upper rim by 80, and its lower rim by 81. The wall of the opening in front of the prominent part of the hip joint 83 is 82. The ends of this unit come and are held together at the lower part of the abdomen by a strap 85 that goes through a snap 86 to make a U-turn and come and stick to its own matching surface. The lower parts of this unit are held in place around the upper thigh areas by ends of the unit which come and are held tight with a matching part by a strap similar to the one mentioned above. This strap in left side is shown by no. 87.
FIGS. 15-17 show a person wearing a hip support unit which is similar to unit shown in FIG. 12, except this unit is made from two pieces, upper and lower, that are held together in front by a common front unit and also by strap 91 in the side that has an elastic component in it. The trunk of the body is 75, and the left thigh 76. The balloon that is standing and protecting the buttock is 79, and the wall of the opening in front of the prominent point of the buttock is shown at 92. The balloon that is standing and protecting the upper thigh and lower buttock is shown at 90. The upper rim of the upper unit is 80 and lower rim of this unit is 94. The upper rim of the lower unit is shown at 93 and lower rim of this unit at 81. The left and right side pieces of the lower unit are held together by a strap 100. The ends of this unit come and are held together in lower side of the abdomen by straps 101 and 102, and the lower parts of this unit are held in place around the upper thigh areas by the ends of the unit coming and being held tight with the matching part by a strap similar to the one mentioned above. These straps are shown at 103 and 104.
The hip support is similar to the other units mentioned earlier. This unit also will be made from combinations of the balloons having a soft cover on the inside surface to prevent discomfort, irritation and inflammation of the skin. The body of the balloons prevents pressure from being applied to the prominent areas or the sore or ulcerated spots. A skeleton or combinations of pieces of soft and hard plastics may be used in make up and the shaping of this unit.
Again, in order to allow the hip joint to bend, this unit will be made from combination of an upper piece and a lower pieces of balloons, which are separated along a horizontal line in the back and in the sides, and the end pieces of these units come to join in front by a common soft and strong pieces of fabric that may have an elastic component in it to be held together by straps to stay in place securely. In the lateral sides, one or more pieces of elastic bands will connect to the upper and lower pieces to help to hold these pieces together securely. This separated construction will allow the hip joints to bend and be functional. The upper piece of this unit has balloons in the back as well as the right and the left side to stand over the buttocks and sides of the hips. The center area of this upper piece has an opening in the back to allow separation of the right and left side pieces for easier mobility of the patient. The lower piece of this unit comprises balloon units that stand around the upper thigh area and its rear and lateral sides but have a fabric piece in the front and inner surface. The front parts of the upper and lower pieces are connected to each other as mentioned above by a natural or synthetic fabrics or straps or wraps which may have elastic components in them. The front piece is to pull the sides and give shape to the unit and allow it to stand in the area as desired. The ends of these units come and are connected to each other by use of straps and snaps and Velcro™ patches. This construction is to give the mobility required for easy mobilization the patient needs. The thickness of this unit and combinations of the balloons will also allow the unit to absorb the pressure and to protect the hip (to some degree) when the person falls down. The fact that the balloons are pressurized will allow dissipation and absorption of some of the pressure from the fall and to prevent the hip injury or to diminish its impact. Pieces of foam, such as used in foam cups, may also be used to help in this purpose. And a layer of latex may also be used in construction of this unit to help in better functioning of the unit in the same way mentioned for previous units. This unit can be worn by some people in order to protect their hip joint and the buttock area from the full impact of a fall.
Such a unit with some modifications may also be used by some concerned persons who may wish to wear it when they go for a walk when there is some chance of falling or for the older vulnerable persons to use in their home when they are subject to fall and injury. The degree of the protection will depend on the size and construction of the balloons and their material so it will be possible to make more protective units that may get heavier and bulkier.
FIGS. 18-20 show a person wearing a hip support unit which is similar to the unit shown in FIG. 15, except this unit also has an opening in front of the prominent point of the side of the hip. This opening will prevent pressure to that spot and protect an ulcer when present. The fact that this unit is made from two separate upper and lower pieces held together gives the advantage that the person can bend his or her hip joint. This unit has also a common front piece, with an elastic component to pull the ends and hold them together. The trunk of the body is shown at 75 and the left thigh 76. The balloon that is standing and protecting the buttock is 79, and the wall of the opening in front of the prominent point of the buttock is 92. The balloon that is standing and protecting the upper thigh and lower buttock is 90. The prominent area of the side of the hip is 83, and its wall is 82. The lower rim of the upper unit is 94, and the upper rim of the lower unit is 93. The common front piece is 77. The upper rim of the upper unit is shown at 80. The ends of this unit come and join and are held together at the lower side of the abdomen by a strap 85 that goes through a snap 86 to make a U-turn and to come and stick to the rear side of its own unit. The lower parts of this unit are held in place around the upper thigh areas by the ends of the unit being held reasonably tight with use of matching straps shown in left side by 87.
The unit for the hip sore provides protection and allow certain care to be provided for patients with ulcerations in their lower back or sides of the hip area due to constant pressure from the bed (bedsores). The general structure and shape of this unit is very similar to the unit mentioned for the hip support. Again, this unit also will be made from combinations of the balloons with a soft cover on their inside surface to prevent discomfort, irritation and inflammation of the skin. Pieces of foam may also be used in construction of this unit. However, in order to allow patient to be able to bend his or her hip joint, this unit may consist from two pieces connected to each other--one upper and one lower. The upper piece of this unit will be similar to one mentioned above except this unit will have openings in the sides, in front of the prominence of the joints in the right and left side, which is to stand on the sides of the hips. The center rear area of this upper piece will have an opening in front of the prominence of the sacrum and prominent points of the spine to allow the ulceration on that area to be exposed to air but not to the pressure. In other words, the opening area will be surrounded by balloons that are higher than the skin and therefore will prevent the ulcer area from touching the surface of the bed. This opening will also allow the local medical therapy to be provided to the area of the ulcer through the opening. The walls of these openings may be fortified by use of pieces of plastics to prevent their collapse under pressure.
The separated construction of the units will allow separation of the right and left side pieces for easy mobility of the patient. The lower piece of this unit will be very similar to the lower piece previously mentioned unit for hip support, which is pieces of balloons that cover the back and sides of the upper thigh area, and the inner ends of those as well as the front side are made from synthetic fabric, straps or wraps. The front part of these pieces are connected to each other by fabric, straps, or a similar material which may have an elastic component in it. The front piece has again the job of pulling the sides to hold the unit together and to give a shape to the unit and allow it to stand in the area as desired. The ends of these units comes and stick to each other by straps and snaps and Velcro™ patches. This construction is to give the mobility required for easy mobilization the patient needs. The thickness of this unit and combinations of the balloons will keep the sore spot above the mattress surface. The walls of these openings may be fortified by use of pieces of plastic to prevent their collapse under the pressure. (Pieces of synthetic foam may also be used in construction of this unit.) While the opening will allow the medical care to be provided to the patient. This opening will also make it possible for a matching piece of soft balloons covered with a piece of gauze to be inserted into the open space and be held by tapes connected to the sides of the unit or by a short strap that goes on this opening. This gauze can be medicated to allow application of antibiotics and different medications to the sore (ulcer area). This will give an unusually unique and great chance for the wound to improve when the medicine can be applied and other skin care to be provided when the pressure is being avoided. Exposure to air and use of heat lamps will also be possible through this opening.
This unit will give the chance that when the patient is lying on his back, the prominent area of the back does not touch the mattress, and also when he sleeps on the sides, the prominent points of his sides would not touch the mattress very much either.
FIGS. 21-23 show a support unit around the knee. This unit is made from a unit similar to one shown in FIG. 1, and this unit has openings in each side in front of the prominent points of the knee. The lower thigh is shown by 110 and the upper leg by 111. The body of the unit is shown by 117. The upper rim of this unit is shown by 115, the lower rim by 116, prominent side of the knee by 112, the upper wall of the opening in front of this prominence by 113 and the lower wall of this opening by 114. FIG. 23 shows how the ends of this unit come together and are connected. In this view, the edge of one end is shown by 119, and a strap 121 from the other side comes to go through a snap 120 and make a U-turn and to stick to the back of the unit from which the strap came. A lower strap is shown by 122.
The unit for the knee is basically similar to the unit mentioned for the ankle, except it has a shape to match and to go around and be held on the knee joint. Its ends come and join together by snaps or a piece of Velcro™. The shape of this unit will have a design to allow the knee to bend due to its special construction with having separate pieces in its front. So, this unit is made from combinations of two (at times more) pieces of balloon units in front; one upper piece and one lower piece. Importantly, these pieces may be connected to each other by a layer of latex. This layer of latex may be stuck or glued to the rear surface of the balloon units. This will give a great advantage of keeping their relation and shape under control and bringing them to the appropriate shape when the joint changes from a closed position to an open one. Alternatively, elastic pieces may be used to do the same job. The rear ends of the front pieces are connected to a common end and then connected to each other in the popliteal area. When the person bends the knee, the upper and lower pieces will separate to allow the bending of the joint to occur. And, when the knee is straightened, the latex layer will pull the upper and lower pieces to come together and stay close, as they should. This unit may have an opening in each side of the knee in front of its prominent points to prevent the very pointed or prominent point of its sides from touching the surface of the mattress or the inside prominence of the opposing knee. Therefore, the prominent point of the knee will be held in the air and away from the pressure. This will also give the best chance for skin care as mentioned earlier.
FIG. 24 shows front view of a piece of balloon that can be inserted inside opening 118 of this unit to provide a method of application of medications and support on an ulcer. Here the border of this unit is shown by 123 and its body by 124. FIG. 25 shows the side view of a piece of balloon shown in FIG. 24. The upper rim of this unit is shown by 123, body by 124, the outer surface by 125, and the soft gauze on it by 126.
FIG. 26 shows a support unit around an elbow of a patient. This unit is made from a unit similar to one shown in FIG. 1 and has openings in each side in front of the prominent points of the elbow, as well as in front of the tip of the elbow. The lower arm is shown by 130 and the upper forearm by 133. The body of the unit is shown by 139, the upper rim by 131, the lower rim by 136, the prominent side of the elbow by 132, the rim of upper wall of the opening in front of this prominence by 134, the lower wall of this opening by 135, the tip of the elbow by 137, and the wall of the opening around the tip by 138. FIG. 27 is to show how using two pieces will allow the person to bend his or her elbow and this unit allows this to happen. In this figure, the elbow is bent. The body of the upper unit is shown by 140. The upper wall of the opening around the tip of the elbow is 142 and the lower wall of this opening is 143.
The unit for the elbow also is very similar to the units mentioned earlier for the ankle and the knees. Similar to the knee unit the shape of this unit will be made to allow the elbow to bend easily due to the separation in the posterior part of the elbow unit in front of the tip of the elbow. Also, this unit may have the openings in each side of the prominent sides of the elbow joint. Again, this construction is to prevent the direct pressure on those important prominent spots, and to allow therapeutic modalities to be given to the sore spot through the openings.
FIGS. 28 and 29 show a patient using a unit made for the head. This unit has a construction similar to the other units, except its shape is different to protect the desired places in the head. This figure shows a unit that goes around the front and the occipital area of the head and also provides protection to the ears. It is held in place by a strap going under the chin and another one connected to the back of the unit that also connects to the piece around the neck or the strap that goes to the lower chin. This unit does also allow a unit that stands against the top of the head to be held in place by its ends connecting to the sides of the unit. A front piece is shown by 151, the body of the balloon by 150, the border of the opening around the ear by 153, the strap that is in the back by 155, the top piece by 156 and its right and left sides by 155, 157. The portion in front of the ear is shown by 152. The sides of this unit are connected to each other under the chin to hold the unit in place.
The Unit for the Head
The dressing of cuts and ulcerated areas of the scalp has been a longstanding problem due to the hair in the scalp, as well as the anatomy of the area. However, this job can be very much simplified with use of a unit that has the same basic construction similar to the previous units. Naturally, this unit has a shape to go around the head and the front area. This is held in place by straps that go under the chin and in the back. This unit allows protection of different parts of the face, ears and the head, and its opening protects the areas and spots intended. It can have an opening to protect the back of the head from pressure too. A particular unit that has an opening in the top allows the bandaging and support of the operated areas of the top of the head to be provided easily after certain skull or brain operations. Like the other units, these openings allow selective dressing of the area protected by openings. The other therapeutic modalities similar to the one mentioned earlier can also be provided through the openings without a need to dismantle the whole unit. The balloon patch that is used is a piece of balloon that matches the size of the opening and it may have a soft cover that will go over the dressing of the scalp and then be held in place by straps that go and stick to the sides of the unit. This is a unique way of dressing the scalp of patients, and it will make it possible to have the dressings changed easily. Importantly, a layer of thin latex with a shape to go over the scalp like a stocking with holes around the eyes and nose and face may be used to hold the pieces of this unit together and on the head and in desired way which will pull and hold the pieces in place properly. This piece will be of great help since it does not have much volume and will not take space. It will be very adaptive to the shape of the area and easily will assume the shape of the area. And, it will prevent change in the shape of the unit. This may prove to save significant time in dressings of lesions of the head.
FIG. 30 shows a series of balloons that are next to each other and are made by dividing one larger balloon by walls to make the smaller balloons. This unit has tubing in its upper and lower sides that works as inflation means for the alternate balloons so that each other balloon can be selectively inflated and also this will make it possible to have alternative and periodic inflation of these balloons two adjacent balloons are shown by 165 and 166, each of which is connected to a different tube. The balloon 165 is connected by opening 170 to tube 171 and finally to inflation port 172. The balloon 166 is connected by opening 169 to tube 167 and then to inflation port 168.
FIG. 31 shows a front view of a balloon which has an almost triangular shape. It has its own inflation port 181.
FIG. 32 shows the side view of the balloon shown in previous figure with the rear surface of this balloon covered by a rough Velcro™ patch 182 and the front face covered by a soft cover 183. The body of the balloon is shown by 180.
FIG. 33 shows a support unit with a surface covered by Velcro™ shown by 184. At the left side of this unit, two balloons similar to the one of FIG. 31 and 32 are stuck. The ends of this unit are shown by 185 and 186.
FIG. 34 shows a support unit similar to the one shown in the previous figure, except this unit has a shape which is rounded and is covered by units of balloons similar to the one shown in FIG. 31. In FIG. 34, the body of the support unit is shown by 190 and a balloon by 193. One end of this support unit has straps 191, and the other end has openings 192 that will allow the straps to go through them.
FIG. 35 shows a patient having a support similar to the one shown in the previous Fig. wrapped around his leg. In this view, the wrap 196 is around leg 195.
FIG. 36 shows a support unit similar to the one shown in FIG. 33 which is covered by three balloons 201, 202, 203 that have different sizes and thicknesses. In this view, the body of the support is shown by 200, its one end by 205, and another end by 204.
FIG. 37 shows the side view of the support unit shown in FIG. 36. This view is to shown how the thicknesses of these balloons may be different. The balloon 201 has more than twice volume of the balloon 203. This view also shows the base of these units connected to the support unit by a Velcro™ system 206.
FIG. 38 shows a supposedly obese patient who is operated with significant amount of fat removed from her one side of abdomen in the right side of the picture. Then, a combination of balloons similar to those shown in the previous Fig. is applied to prevent leakage of blood and fluid, disfigurement of the area, and to help in displacement and shaping of the area. In this view, the balloons are wrapped around the body and the abdomen. This is a cross-cut view and shows the inside of the abdomen in the center at 210 surrounded by the fat layer 211 which has some part of that removed in the right side of the picture and replaced by the balloons. The support 200 is shown with its ends 204, 205 extending to the sides to wrap around the body. The balloons 201, 202, 203 almost match and compensate for the amount of fat removed.
FIGS. 39-42 show a latex unit that here is chosen to show a prototype of this unit. In this case, it is a unit that will go over and around the elbow joint to hold the unit in place and also to allow the washing of the areas above and below this area to occur. This unit has a shape to go over the protective unit of the elbow and to stay in place due to its internal elastic function. In the upper as well as the lower openings of this unit, which is made to stand like a sleeve in place, there will be a couple of lines of fortified latex which are intentionally made to go all around the limb and prevent water from coming inside the unit. (This fortified area will be like adding a rubber band to the unit, and, in some cases, a rubber band may also be used for such purpose.) This will give the opportunity for a patient's body and arm to be washed and cleaned without contaminating the area. Small tabs of elastic are placed outside of the ends of this unit to make it possible for the elastic ends to be held and pulled. The upper end of this unit is 220, the one of the fortified lines in the upper area is 225, the body of the unit is 221, and expandable area to stand in front of the tip of elbow is 224. The lower end is 223 and one line of fortified latex is 226. The tabs of the upper end are 230, 231 and 232, and in the lower end they are 233, 234 and 235.
FIG. 40 shows the special design of the area which is to stand at the tip of elbow. This area is shown by 224 and is designed to have extra latex which will make a wall like that of an accordion. This will allow the unit to expand in this side when the elbow is bent. I believe this is a great advantage that will prevent change of shape and function of the unit in this area when the elbow is bent. This will also be true in units made for knee or hip, etc. to give a better functional unit.
FIG. 41 shows a patient using the unit on his elbow. This figure shows how the upper and lower ends of this unit function like a sleeve and are reasonably tight around the place. This figures show that the bend of the elbow has not caused much of a problem in the tip of the elbow.
FIG. 42 shows the opening of the upper part of this unit and the positions of the small tabs. In this Fig., 220 is the inside of the opening and 229 is the wall of the opening. The small tabs look in this view like a line and they are marked in each side by 232, 231, 230 and 236.
A Unit for the Wrist (not shown) is basically similar to the previous units for the support of the other joints except the shape of the unit will match the shape of the wrist and upper hand. The unit is made from one piece for immobilization of the wrist, and a unit made from multiple pieces will allow motion of the wrist to occur. The unit can be wrapped and be closed from the front or the back, whichever appears more appropriate for the case.
In order to prevent skin problems and infections and to give better care and cleanness to an area, a disposable lining made from soft absorbing material, such as cotton, that will have a shape to match and go around the joints mentioned above will stay under the units and be exchanged daily for better care of the skin and the area. The ends of this lining have an adhesive rim or bands with adhesive surface covered and supported by a layer of plastic that is removed to allow the connection of the edges to occur. The size and shape of this lining will vary. In practice, this lining is used under the unit and the unit is applied on it. In these cases, the inner surfaces of the unit do not need to have a very fine lining since the liners will do their job. However still the inner surface of the unit has to be soft and comfortable.
The idea of using balloons for support is very unique and useful and can be used in other cases too. I believe it will be very helpful in many other circumstances. This will be specially true after surgeries for prevention of bleeding and holding the operation site stable. I would like to say though that it is not always possible for a complete unit to be made for every case. To solve this problem and to have more choices which always is better, a support unit can be made from a soft, non-stretchable fabric that has a surface covered with patches of Velcro™. This unit will allow sticking different size and shapes of balloons that have a rear surface with a matching patches of Velcro™ so that these combinations will allow particular and more appropriate balloons to be chosen and be applied in place with use of the support system. This will also give the chance of changing the balloons when it comes to be necessary and also when a balloon is popped or torn.
These balloons may have their own inflation ports to allow them to be inflated individually to the level desired or to be connected to a connection tube that will allow groups of the balloons to be inflated by one port. This unique construction will give the chance to choose different size balloons and to make a customized unit for a particular patient to match his or her size and condition and special location , the need for use exists. The shapes of the balloons can be different and vary significantly.
The need for such units may be easy to understand when we consider that the size of people and the types of surgery they undergo is different, and that a need for many options is real for choosing a unit to be used in special circumstances. For example, I want to be open and give my own reason for stressing this matter. In my free imaginations, one time I thought to find a way to help a nice nurse that I see occasionally in my job. She is not my patient and has not complained to me about her problem. However this has not prevented me from thinking about a solution for that young lady and the people like her that in my observation do suffer tremendously from the very heavy weight they have. I have no question in my mind that their morbid weight will cause them a major complication if not corrected. This has been true about some of my other patients, and I have reached a conclusion in my own mind that we should be able to operate on these patients to remove fat or to do lipo-suction periodically to remove the tremendous extra fat and related heavy weight to diminish the job of their heart and lungs and joints, etc. The fact that my patients, even after referral to major centers have not received help, make me believe that there is no help available. This makes me think about removing those fat masses surgically with a strong medical back up. In finding a solution I thought that after a mass of fat is removed, it would be much better, if not necessary, to apply a pressurized balloon in the area to prevent bleeding from the area, fluid accumulation in the area, and looseness of the skin, etc.
The balloons will help to maintain a symmetrical shape for the patient until the total plan of treatment is carried out. Also, more importantly, the pressure from the unit and the balloons may help in reshaping the rest of the fat in the operation area under the skin to prevent lumps of fat from being accumulated and to stay in one point when more likely the pressure will help in reshaping the surface under it to be smoother and better. To illustrate my reason behind the need for many and multiple shape balloons, I would like to use this example that in such case a surgeon may have to remove the fat only from one side of the abdomen to prevent very extensive intervention and to leave the other side for the next time, and also to work in another side such as the thigh or leg or arm, etc. Also, let us consider a case after surgery for varicose veins which I believe a long balloon to apply pressure to the procedure site will be very beneficial, and this is also a case to show a need for different units. And for this reason, I decided to introduce these particular units that will give the chance of making a variety of different balloons. And I want also to choose this example to claim that these units will also be very useful after many surgeries for prevention of hematoma and bleeding, etc., after the surgery.
So there is need for variety of balloons that some may be inflated as group and, in some cases, we may wish to inflate them periodically to avoid a constant pressure to one area to compromise circulation, etc. In some cases, the time may dictate us to change the size of the balloon, etc. However I have no doubt in my mind that these units will be very effective.
I also believe that these units may be used effectively to press a focal site such as side of the thigh or legs or buttocks of people, mostly ladies, to help them to lose fat in that particular spot which is a very, very important cosmetic problem for some women and unfortunately brings it's psychological reaction and problem with their self-image and does cause marital problems.
I believe the units I introduced will prove over the time to show their great advantages and to help many patients. That is the reason I am proceeding with this application.
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Various support devices have one or more balloons that are strapped around a portion of the body with a soft layer between them and the body. In some devices, the balloons are separably mounted a strap that encircles a portion of the body. Various forms of balloons are disclosed. In other devices, the balloon has an open area that is disposed over a bony prominence or ulcerated area. An insert for applying medicine may be disposed within the open area. Certain devices are for body joints and therefore have multiple parts that can move toward and away from each other as the joint flexes.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 61/644,275 entitled “WIFI MOTOR” filed on May 8, 2012 which is hereby incorporated by reference for all purposes in its entirety.
BACKGROUND
[0002] Window coverings can be used to cover a window and/or a portion of a wall. In many cases, window coverings can be used for managing sunlight, creating privacy, or other functional purposes. Window coverings can additionally provide a variety of decorative features to enhance the enjoyment of a space. Some window coverings are attached to a motorized window covering assembly to aid a user in opening and closing the window covering.
[0003] Motorized window covering assemblies holding window coverings such as curtains and blinds are often unattractive due to the visual appearance of the motor assembly and related parts. For example, motors used to automate the opening and closing of the window coverings may be located in plain sight or may be covered by a light window covering fabric, creating an unpleasant visual experience for the user. Where control lines or wires are needed to control the motors, they may be run so as to create an eye sore. A setup box has historically been needed to integrate traditional motors into WiFi systems for controlling the motors remotely. The setup box may be located in plain sight or in a location that is visually unattractive. There is a need for motor assemblies that increase the attractiveness of motorized window covering assemblies.
[0004] Motorized window covering assemblies are costly. The setup boxes, which have historically been needed to integrate traditional motors into WiFi systems for controlling the motors remotely, have a limited range. Consequently, a number of setup boxes may be needed when the motors are spread over a wide range (e.g., throughout a house or building). Additionally, the setup boxes are costly, increasing the cost of installing motorized window covering assemblies. There is further cost associated with devices used by users, such as remote controls, to send commands to the window covering assemblies to open and close the window coverings. There is a need to reduce the cost of installing motorized window covering assemblies.
[0005] Motorized window covering assemblies historically could only be controlled by a user when the user was within a limited range. The devices used by users to send commands to the window covering assemblies have a limited range. A user outside of this range will not be able to control, for example, a window shade in their bedroom or living room. In houses or buildings with a large number of motorized window covering assemblies, a single user with a single device may not be able to control each of the window covering assemblies in the house or building. This prevents, for example, a central command center in a large building from controlling all the motorized window covering assemblies in the building. There is a need to improve the ability to control motorized window covering assemblies.
SUMMARY
[0006] Various embodiments of the present invention are directed to apparatuses and methods of motorized window covering assemblies. More specifically, various embodiments of the present invention relate to apparatuses and methods of attractive motorized window covering assemblies, of low cost motorized window covering assemblies, of controllable motorized window covering assemblies, or of other features of motorized window covering assemblies. It is not necessary for all embodiments of the invention to have all the advantages of the invention or fulfill all the purposes of the invention. The use of a motor with an integrated WiFi interface enables the elimination of the setup box, resulting in a lower cost. Eliminating the setup box and any lines or wires associated with the setup box additionally eliminates the eye sore that they may pose. This, along with an elongated motor assembly used in some embodiments, enables the motor assembly to be made less noticeable by, for example, making the motor assembly easier to hide or camouflage.
[0007] As one example of hiding the motor assembly, an elongated motor assembly, comprising an elongated casing surrounding the motor and the control board, is hidden inside of the window covering holder. As another example, the elongated motor assembly is integrated into other parts of the physical structure of the window covering assembly in a manner that makes the motor assembly less noticeable. Hiding or camouflaging the motor assembly makes the motorized window covering assembly correspondingly more attractive.
[0008] Using a remote device (e.g., a laptop), an IP address can be assigned to each motor, enabling each motor to be individually addressed and controlled from any remote device located anywhere in the world with access to the internet. This enables an increased ability to control the motorized window assemblies. For example, a user in an office building control station can, using one remote device, or one server configured as a central control system, control any of the motorized window covering assemblies in the building.
[0009] Some embodiments of the disclosed apparatus comprise a motor, a window covering holder coupled to the motor, and a control board communicably coupled to the motor. The control board includes a WiFi interface to receive control signals. The control board controls, by providing current or voltage, operation of the motor in accordance with the control signals received through the WiFi interface. The motor causes at least a portion of the window covering holder to move such that a window covering attached to the window covering holder would also move. The motor can be a DC motor, a brushed DC motor, a brushless DC motor, an AC motor, or a stepper motor. The control board can include a motor control unit having at least one control interface. The window covering can be attached to the window covering holder. The window covering can be a curtain, a blind, a drape, a screen, a shade, a roller, or a shutter. The control board provided current or voltage to control the operation of the motor can communicate digital signals. Some of the embodiments can further include a power supply board, a step-down transformer, or a rectifier, and can additionally include an RF interface communicably coupled to the control board. An RF device can send control signals which are received through the RF interface, and the control board can control the operation of the motor in accordance with the received control signals. The WiFi interface and the RF interface can be an integrated WiFi/RF module.
[0010] In some embodiments, an elongated casing surrounds the motor and the control board. The window covering holder can be the elongated casing surrounding the motor and the control board. The window covering holder and the elongated casing can both have a cylindrical shape. A portion of the window covering holder can be hollow, and the elongated casing, including the motor and the control board that it surrounds, can be located inside of the hollow portion of the window covering holder. The hollow portion of the window covering holder can extend from a first end of the window covering holder to a second end of the window covering holder, and the elongated casing can extend from the first end of the window covering holder to the second end of the window covering holder. The second end of the window covering holder can have an end cap, and the second end of the casing can have an end cap. The elongated casing can be made of a composite material, for example plastic. The elongated casing can be made be for dissipating heat, absorbing noise, reducing weight, or preventing electrical conduction.
[0011] Some embodiments comprise an elongated motor assembly and a window covering holder coupled to the elongated motor assembly. The elongated motor assembly includes a motor, a control board communicably coupled to the motor, and an elongated casing enclosing the motor and the control board. The control board controls operation of the motor in accordance with received control signals. The window covering holder and the elongated casing both have a cylindrical shape. A portion of the window covering holder is hollow, and the elongated motor assembly is located inside of the hollow portion of the window covering holder. The operation of the motor causes at least a portion of the window covering assembly to move such that a window covering attached to the window covering holder would also move. Some of the embodiments can include an RF interface communicably coupled to the control board. The received control signals, which can be sent by an RF device, can be received via the RF interface.
[0012] Some embodiments are methods for controlling a WiFi motorized window covering assembly, the method comprising receiving control signals and controlling the operation of a motor in accordance with the received control signals. The control signals are received by a WiFi interface on a control board communicably coupled to a motor. An elongated casing surrounds the motor and the control board. The motor is mechanically coupled with a window covering holder. The operation of the motor causes at least a portion of the window covering holder to move such that a window covering attached to the window covering holder would also move. The control signals that are received by the WiFi interface can be generated by a remote device. The remote device can download an application to enable the remote device to generate the control signals that are received by the WiFi interface. The control signals can be transmitted through a network, or they can be received by the WiFi interface directly from the remote device. Some of the embodiments further comprise receiving, by an RF interface on the control board, control signals from an RF device. The WiFi interface and the RF interface can be an integrated WiFi/RF module. The remote device generated control signals can be received by a plurality of WiFi interfaces, each WiFi interface on a control board communicably coupled to a motor.
[0013] Some embodiments comprise a plurality of WiFi motorized window covering assemblies, a network, a central control system, and at least one remote device. The central control system sends a common command to at least two of the plurality of WiFi motorized window covering assemblies. A user undertakes one sequence of steps that causes the central command system to send the common command. Some of the embodiments further comprise at least one RF device.
[0014] While multiple embodiments are disclosed, still other embodiments of the present invention will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the invention. As will be realized, the invention is capable of modifications in various aspects, all without departing from the scope of the present invention. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Embodiments of the present invention will be described and explained through the use of the accompanying drawings in which:
[0016] FIG. 1 illustrates a motor assembly;
[0017] FIG. 2 illustrates a casing;
[0018] FIG. 3 illustrates a motorized window covering assembly with an attached window covering;
[0019] FIG. 4 is a block diagram illustrating a control board;
[0020] FIG. 5 is a flow chart illustrating operations for controlling a WiFi motorized window covering assembly; and
[0021] FIG. 6 illustrates a network of WiFi/RF motorized window covering assemblies.
[0022] The drawings are not necessarily drawn to scale. For example, the dimensions of some of the elements in the figures may be expanded or reduced to help improve the understanding of the embodiments of the present invention. Similarly, some components and/or operations may be separated into different blocks or combined into a single block for the purposes of discussion of some of the embodiments of the present invention. Moreover, while the invention is amenable to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and are described in detail below. The intention, however, is not to limit the invention to the particular embodiments described. On the contrary, the invention is intended to cover all modifications, equivalents, and alternatives falling within the scope of the invention as defined by the appended claims.
DETAILED DESCRIPTION
[0023] Various embodiments of the present invention are directed to apparatuses and methods of motorized window covering assemblies. More specifically, various embodiments of the present invention relate to apparatuses and methods of attractive motorized window covering assemblies, of low cost motorized window covering assemblies, of controllable motorized window covering assemblies, or of other features of motorized window covering assemblies. It is not necessary for all embodiments of the invention to have all the advantages of the invention or fulfill all the purposes of the invention.
TERMINOLOGY
[0024] Brief definitions of terms, abbreviations, and phrases used throughout this application are given below.
[0025] The terms “connected” or “coupled” and related terms are used in an operational sense and are not necessarily limited to a direct physical connection or coupling. Thus, for example, two devices may be coupled directly, or via one or more intermediary media or devices. As another example, devices may be coupled in such a way that information can be passed there between, while not sharing any physical connection with one another. Based on the disclosure provided herein, one of ordinary skill in the art will appreciate a variety of ways in which connection or coupling exists in accordance with the aforementioned definition.
[0026] The phrases “in some embodiments,” “according to various embodiments,” “in the embodiments shown,” “in one embodiment,” “in other embodiments,” “various embodiments,” “some embodiments,” and the like generally mean the particular feature, structure, or characteristic following the phrase is included in at least one embodiment of the present invention, and may be included in more than one embodiment of the present invention. In addition, such phrases do not necessarily refer to the same embodiments or to different embodiments.
[0027] If the specification states a component or feature “may”, “can”, “could”, or “might” be included or have a characteristic, that particular component or feature is not required to be included or have the characteristic.
[0028] The term “module” refers broadly to software, hardware, or firmware (or any combination thereof) components. Modules are typically functional components that can generate useful data or other output using specified input(s). A module may or may not be self-contained. An application program (also called an “application”) may include one or more modules, or a module can include one or more application programs.
General Description
[0029] FIG. 1 illustrates a motor assembly in accordance with various embodiments of the present invention. As illustrated in FIG. 1 , the motor assembly is an elongated motor assembly and includes a control board 105 , a WiFi/RF module 110 , a motor 115 , a casing 120 , a heat sink 125 , and a power supply board 130 . Other embodiments of the present invention can include some or all of these components. Still yet, additional components and/or modules can be included in some embodiments of the motor assembly.
[0030] Control board 105 includes an interface module for transmitting and receiving data and/or commands for controlling motor 115 . The interface module is an integrated WiFi/RF module 110 . The WiFi/RF module 110 is configured to transmit and/or receive data, control signals, or commands through a network, such as network 605 in FIG. 6 , or directly to/from an RF device, such as RF device 625 in FIG. 6 , or a remote device, such as remote device 620 in FIG. 6 . The control signals received through the WiFi/RF module 110 are converted, by control board 105 , into a current or voltage to control the operation of the motor in accordance with the control signals. The current or voltage can communicate digital signals which represent the control signals and/or the commands for controlling the operation of the motor 115 .
[0031] The digital signals can be received by one or more components or devices that convert the received digital signals into a second current or voltage that powers the motor such that motor operates in accordance with the received digital signals which represent the control signals. Alternatively, the control board 105 converted current or voltage can power the motor such that motor operates in accordance with the received control signals. The powering of the motor by the current or voltage can involve the current or voltage powering the motor directly, or can involve the current or voltage entering components, devices, or circuits such as rectifiers, transformers, step down transformers, waveform conditioning circuits, and/or waveform amplifying circuits and being transformed into a third current or voltage which can power the motor such that motor operates in accordance with the received control signals. The WiFi/RF module can be used to interface with wireless networks, remote devices, and/or RF devices, such as RF device 625 of FIG. 6 , which can be an RF remote control, or an RF remote using touch, Wii technology, or voice interface.
[0032] Remote devices, such as remote device 620 in FIG. 6 , include smart phones, tablets, laptops, personal computers, computers, servers, and/or other devices used to control the operation of the motor. Using a remote device, an IP address can be assigned to each motor. Various embodiments allow the user to download one or more applications to a remote device to provide a user interface on the remote device to control the operation of the motor. Once a motor is assigned an IP address, it can send and/or receive data, control signals, or commands to/from any other device with an IP address, and the operation of the motor can be controlled according to any received control signals or commands. Using a remote device, a user can control the operation of the motor from anywhere in the world as long as the remote device has Internet access at that location. The remote device can send and/or receive data, control signals, or commands to/from the motor over a network, for example, a local area network, a wide area network, a cellular network, and/or the internet. The data, control signals, or commands can be sent/received over the network to/from a device that can relay the data, control signals, or commands over a wireless network to/from the WiFi module 110 . Once received through the WiFi/RF module 110 , the control board controls the operation of the motor in accordance with the received control signals or commands.
[0033] Motor 115 can be any type of motor and can be chosen based on the desired application, cost, power requirements, availability, and/or other criteria. For example, the motor can be a DC motor, a brushed DC motor, a brushless DC motor, an AC motor, a stepper motor, and the like. Depending on the type of motor and application, a motor control module/unit can be communicably coupled to control board 105 . The motor control module/unit can provide the necessary interface signals for controlling motor 115 .
[0034] Casing 120 is an elongated casing and can be used to surround control board 105 and motor 115 . Additionally, other components can be enclosed within casing 120 such as, but not limited to heat sink 125 , power supply board 130 , a step-down transformer, a rectifier, waveform conditioning circuits, waveform amplifying circuits, and/or other components.
[0035] FIG. 2 illustrates an exemplary casing. Casing 205 is an elongated casing and can have a variety of properties such as, but not limited to, preventing electrical conduction (i.e. being an electrical insulator), quick heat dissipation, noise absorption, and/or being light weight. Casing 205 can be made of one or more composite materials such as plastic. Casing 205 can have any elongated shape. For example, casing 205 can have a cylindrical shape. The cylindrically shaped elongated casing 205 has a circular cross section 210 . The elongated casing 205 can have an elongated shape where the cross section is a square, a rectangle, an oval, a triangle, a pentagon, a trapezoid, a hexagon, an octagon, or some other shape.
[0036] In some embodiments, the shape of the elongated casing is chosen to optimize the ability to locate the motor assembly (e.g., the elongated casing 205 and an enclosed motor and control board) inside of a window covering holder, so as to hide the motor assembly from view. To enable the hiding of the motor assembly, the window covering holder can have a hollow portion inside of which the motor assembly is located. In some of the embodiments where the window covering holder has a cylindrical shape and a cross section that is a circle, the window covering holder can have a hollow portion that has a similar but smaller cross section and shape. In order to locate the motor assembly inside of this window covering holder, the motor assembly can have a similar and even smaller cross section and shape, sized so as to enable the elongated casing 205 , including an enclosed motor and circuit board, to fit in the hollow portion of the window covering holder. In some of the embodiments, the window covering holder can have a complex shape and can have a hollow portion that has, for example, a square or rectangular or irregularly shaped cross section.
[0037] In each of these examples, the elongated casing can have a shape that is optimized to fit inside of the hollow portion of the window covering holder. In the case of the window covering holder having a hollow portion with a rectangular or square cross section, the casing can have a similar but smaller cross section sized so as to enable the elongated casing 205 , including an enclosed motor and circuit board, to fit in the hollow portion of the window covering holder. In the case of the window covering holder having a hollow portion with an irregularly shaped cross section, the elongated casing can have a shape and associated cross section chosen to optimize the ability to locate the motor assembly inside of the hollow portion of the window covering holder.
[0038] FIG. 3 illustrates an exemplary motorized window covering assembly with an attached window covering. Window covering holder 330 holds window covering 325 . Window covering holder 330 has a hollow portion, inside of which the motor assembly is located, the motor assembly comprising the elongated casing 320 , the enclosed motor 315 and the enclosed circuit board 305 , both the motor 315 and circuit board 305 enclosed in the elongated casing 320 . The circuit board includes WiFi/RF module 310 . The hollow portion of window covering holder 330 can extent a portion of the length of window covering holder 330 , or can extend the entire length of window covering holder 330 . The elongated casing 320 can extend a portion of the length of window covering holder 330 , or can extend the entire length of window covering holder 330 . The window covering holder 330 can have an end cap on one end, and the elongated casing 320 can similarly have an end cap on one end. In some embodiments, window covering holder 330 is the elongated casing enclosing motor 315 and control board 305 (i.e. there is no separate elongated casing and window covering holder, they are one and the same).
[0039] Window covering holder 330 can hold the window covering by the window covering 325 being attached to the window covering holder 330 . The window covering 325 can be attached to the window covering holder 330 by an adhesive. The window covering 325 can be attached to the window covering holder 330 by a portion of the window covering 325 being inserted into a slot, hole, groove or a trench of window covering holder 330 . The window covering 325 can be attached to the window covering holder 330 with fasteners such as screws, nails, pins, clips, rivets, clamps, staples, and other types of fasteners.
[0040] Window covering holder 330 can have various shapes and still be functional. As a non-limiting example, window covering holder 330 can be a curtain track and associated curtain carriers. The curtain track can accommodate a curtain carrier that rolls/glides in the track of the curtain track. The curtain carrier can have a hook for attaching to the window covering, an example of the window covering being a curtain. In this example, the operation of the motor causes a portion of the curtain holder (i.e. the curtain carrier) to move (i.e. to roll/glide in the track), such that a window covering (i.e. a curtain) attached to the window covering holder (i.e. a curtain hung on the curtain carrier hooks) would also move. As is well known to those skilled in the art, there are many different types of window covering holders and many different ways of attaching window coverings to those window cover holders. Some examples of window covering holders and methods of attaching window coverings to the window covering holder are provided to help make the disclosure more understandable, and the examples are not intended to be limiting in any way. One skilled in the art will be able to select a variety of window covering holders and, for each, an appropriate method of attaching a window covering to the window covering holder.
[0041] FIG. 4 illustrates a block diagram of an exemplary control board. An exemplary control board 405 comprises processor(s) 410 , main memory 420 , non-volatile memory 425 , WiFi/RF module 430 , and bus 415 . The WiFi/RF module 430 receives and/or transmits control signals, commands and/or data, the receiving and/or transmitting accomplishing communication between WiFi/RF module 430 and an RF device, such as RF device 625 of FIG. 6 , or a remote device, such as remote device 620 of FIG. 6 , or with both devices. The RF device or remote device can download an application to enable the device to communicate with the WiFi/RF module 430 . The received and/or transmitted control signals, commands and/or data can be communicated with the remote device through a network, such as network 605 in FIG. 6 , in which case the control signals, commands and/or data will be relayed between the WiFi module and the network by a device which communicates with WiFi/RF module 430 using a wireless network, an example of the device being a WiFi router. The received or transmitted control signals, commands and/or data can additionally be communicated directly with a remote device and/or an RF device.
[0042] Bus 415 provides a communication means for communicating between main memory 420 , non-volatile memory 425 , WiFi/RF module 430 and/or processor(s) 410 . Any or all of main memory 420 , non-volatile memory 425 , and/or WiFi/RF module 430 can be integrated with processor(s) 410 . Bus 415 can be entirely on control board 405 , can be partially on control board 405 and partially integrated with processor(s) 410 , or can be entirely integrated with processor(s) 410 . A person having ordinary skill in the art will recognize that there are many options well known in the art for implementing bus 415 .
[0043] Control board 405 further comprises main memory 420 . Main memory 420 can be any device, mechanism, or populated data structure for storing information and can encompass any type of, but is not limited to, volatile memory, non-volatile memory, and dynamic memory. For example, main memory 420 can be a random access memory (RAM), dynamic random access memory (DRAM), flash memory including NAND or NOR flash, SDRAM, SIMM, DIMM, RDRAM, DDR RAM, or any other type of memory device. Main memory 420 can be a device communicably coupled to control board 405 or can be integrated with processor(s) 410 . Main memory 420 is coupled to bus 415 and stores information and instructions to be executed by processor(s) 410 . Main memory 420 can further be used for storing temporary variables or other intermediate information during execution of instructions by processor(s) 410 .
[0044] Control board 405 further comprises non-volatile memory 425 . Non-volatile memory 425 , for example, can be a read only memory (ROM), EPROM, EEPROM, or a flash memory including NAND or NOR flash. Non-volatile memory 425 can be a device communicably coupled to control board 405 or can be integrated with processor(s) 410 . Non-volatile memory 425 is coupled to bus 415 and stores information and instructions to be executed by processor(s) 410 . Main memory 420 and non-volatile memory 425 can be separate memories, or can both be a single non-volatile memory (i.e. a single non-volatile memory provides the function of both main memory 420 and non-volatile memory 425 ).
[0045] Control board 405 further comprises processor(s) 410 . The processor(s) 410 can be, or can include, one or more programmable general-purpose or special-purpose microprocessors, digital signal processors (DSPs), programmable controllers, application specific integrated circuits (ASICs), programmable logic devices (PLDs), trusted platform modules (TPMs), or the like, or a combination of such devices. Any or all of main memory 420 , non-volatile memory 425 , and/or WiFi/RF module 430 can be integrated with processor(s) 410 . Bus 415 can be entirely on control board 405 , can be partially on control board 405 and partially integrated with processor(s) 410 , or can be entirely integrated with processor(s) 410 .
[0046] Control board 405 can further be communicably coupled to other components such as, but not limited to, a WiFi module/interface, an RF module/interface, a power supply board, a step-down transformer, a rectifier, a waveform conditioning circuit or device, a waveform amplifying circuit or device, a mass storage device such as a hard disk drive or a solid-state drive, a removable storage media device such as a USB memory device, a thumb drive or a flash card, a capacitor, a resistor, or an inductor. Circuit board 405 and/or any device associated with circuit board 405 can additionally be connected to a heat sink.
[0047] FIG. 5 is a flow chart illustrating exemplary operations for controlling a WiFi motorized window covering assembly. In accordance with some embodiments of the present invention, one or more of the operations illustrated in FIG. 5 can be performed by the RF device, the remote device, and/or the various components/devices comprising the motorized window covering assembly. As illustrated at operation 505 , an application is downloaded which enables the remote device to generate control signals. An example of the remote device is remote device 620 of FIG. 6 . The application can be additionally downloaded by the RF device. The application can be software or firmware and can be initially provided to the RF device or remote device by downloading it from a remote system. The software or firmware of the application can further be pre-installed on the RF device or remote device, or can be installed from a non-volatile storage device. The non-volatile storage device can be, for example, a CD ROM, a DVD, a Blu-ray disc, a hard disk drive, a solid-state drive, a removable storage media device such as a USB memory device, a thumb drive or a flash card. When the application is run by the RF device or the remote device, the application configures the device enabling it to send control signals to the WiFi and/or RF module/interface.
[0048] Operation 510 transmits the control signals, through a network or directly, to a WiFi interface. An example of the network is network 605 of FIG. 6 . The WiFi interface is synonymous with the WiFi module (i.e. they are one and the same). The control signals can additionally be transmitted to the RF module/interface. The RF interface is similarly synonymous with the RF module. The remote device transmits the control signals, and the control signals are communicated to the WiFi module/interface. The control signals can be transmitted through a network, in which case the control signals will be relayed by a device, for example a WiFi router, over a wireless network to the WiFi module/interface. The control signals can additionally be transmitted directly from the remote device to the WiFi module/interface, the remote device transmitting electromagnetic waves that are directly received by the WiFi module/interface. The control signals can additionally be transmitted directly from the RF device to the RF module/interface, the RF device transmitting electromagnetic waves that are directly received by the RF module/interface. An example of the RF device is RF device 625 of FIG. 6 .
[0049] Operation 515 receives, by the WiFi interface on a control board communicably coupled to a motor, control signals. The control signals can further be received by an RF interface or by an integrated WiFi/RF interface on a control board communicably coupled to a motor. The control signals can further be received by an RF interface, a WiFi interface, or an integrated WiFi/RF interface, the interface integrated with the processor(s) on the control board communicably coupled to the motor.
[0050] Operation 520 controls the operation of the motor in accordance with the received control signals. The control board is communicably coupled to the motor, the communicable coupling enabling the control board to control the operation of the motor. The control board can control the operation of the motor by sending digital signals representing the received control signals or, alternatively, analog waveforms. The digital signals can be received by one or more components or devices that convert the received digital signals into a second current or voltage that powers the motor such that motor operates in accordance with the received control signals. The analog waveforms are a current or voltage that can power the motor such that motor operates in accordance with the received control signals. The powering of the motor by the current or voltage can involve the current or voltage entering components, devices, or circuits such as rectifiers, transformers, step down transformers, waveform conditioning circuits, and/or waveform amplifying circuits and being transformed into a third current or voltage which can power the motor such that motor operates in accordance with the received control signals.
[0051] Operation 525 moves a window covering by the operation of the motor. The operation of the motor, being controlled by the control board in accordance with the received signals, converts electrical energy to mechanical energy. The motor is mechanically coupled to the window covering holder, and a portion of the mechanical energy of the motor is transferred to the window covering holder through this mechanical coupling, resulting in at least a portion of the window covering holder moving. As one non-limiting example, the window covering can be a blind and the blind can be attached to a cylindrically shaped window covering holder with adhesive. As the window covering holder spins around the central axis of the cylindrical window covering holder, the blind wraps around the holder, or unwraps from the holder, thereby raising or lowering the blind. As a second non-limiting example, the window covering can be a drape and the window covering holder can be a curtain track and associated curtain carriers. The curtain carrier can have a hook that is used to attach the drape to the curtain carrier. A portion of the mechanical energy of the motor is transferred through a mechanical coupling to the curtain carriers, the curtain carriers resultantly moving along the track of the curtain track. As the curtain carriers move, they open or close the attached curtain.
[0052] Operation 530 receives, by an RF interface on the control board, control signals from an RF device. The RF interface can be a module on the control board, can be part of an integrated WiFi/RF interface on the control board, can be an RF interface integrated with the processor(s) on the control board, or can be part of an integrated WiFi/RF interface integrated with the processor(s) on the control board.
[0053] FIG. 6 illustrates an exemplary network of WiFi/RF motorized window covering assemblies. The exemplary network of WiFi/RF motorized window covering assemblies comprises network 605 , a plurality of WiFi/RF motorized window covering assemblies 610 , server 615 , remote device 620 , and RF device 625 . As long as remote device 620 and server 615 have access to the network, remote device 620 and/or server 615 can transmit and/or receive control signals, commands, and/or data though network 605 to/from the WiFi interface of an integrated WiFi/RF module of any or all of the plurality of WiFi/RF motorized window covering assemblies 610 . As long as a selected one of the plurality of WiFi/RF motorized window covering assemblies 610 is within the range of RF device 625 , RF device 625 can transmit and/or receive control signals, commands and/or data directly to/from the RF interface of the integrated WiFi/RF module of the selected one of the plurality of WiFi/RF motorized window covering assemblies 610 .
[0054] Network 605 is an IP based communications link between the plurality of WiFi/RF motorized window covering assemblies 610 , remote device 620 , and server 615 . Network 605 can be a local area network, a wide area network, a cellular network, a WiFi network, the internet, or various other communications networks supporting IP based communications. In some cases, the communications link may be comprised of multiple networks, even multiple heterogeneous networks, such as one or more border networks, voice networks, broadband networks, service provider networks, Internet Service Provider (ISP) networks, and/or Public Switched Telephone Networks (PSTNs), interconnected via gateways operable to facilitate communications between and among the various networks.
[0055] Server 615 provides the function of a central control system by providing the ability to manage the plurality of WiFi/RF motorized window covering assemblies 610 . One or more applications can be downloaded which enable Server 615 to generate control signals to control the operation of the plurality of WiFi/RF motorized window covering assemblies 610 and/or to provide the function of a central control system. The application(s) can be software or firmware and can be initially provided to server 615 by downloading it from a remote system. The software or firmware of the application(s) can further be pre-installed on server 615 , or can be installed from a non-volatile storage device. The non-volatile storage device can be, for example, a CD ROM, a DVD, a Blu-ray disc, a hard disk drive, a solid-state drive, a removable storage media device such as a USB memory device, a thumb drive or a flash card. When the application(s) is run by server 615 , the application(s) configures server 615 enabling it to send control signals to control the operation of the plurality of WiFi/RF motorized window covering assemblies 610 and/or to provide the function of a central control system.
[0056] The central control system can undertake various tasks or provide various functions that span or are optimized to support the plurality of WiFi/RF motorized window covering assemblies 610 . The central control system can, as one non-limiting example, track the current position of the window coverings attached to the plurality of WiFi/RF motorized window covering assemblies 610 . This can be accomplished by, for example, tracking the current position of the motor, the motor's current position corresponding to the window covering in a certain position The central control system can, as a second example, track the functionality status of the plurality of WiFi/RF motorized window covering assemblies 610 .
[0057] The central control system can also provide functionality intended to optimize the control of the plurality of WiFi/RF motorized window covering assemblies 610 . For example, the system can provide the ability for a user to send a common command to each of the plurality of WiFi/RF motorized window covering assemblies 610 . Rather than the user having to repeat a sequence of steps each time the user sends a common command to each of the plurality of WiFi/RF motorized window covering assemblies 610 (e.g., a sequence of 3 steps repeated for each of 10 WiFi/RF motorized window covering assemblies for a total of 30 steps undertaken by the user in order to cause the common command to be sent to each of the 10 WiFi/RF motorized window covering assemblies), the central control system can provide functionality that enables the user to undertake one sequence of steps that causes the common command to be sent to each of the plurality of WiFi/RF motorized window covering assemblies 610 (e.g., the user undertakes a sequence of 5 steps which causes a common command to be sent to each of 10 WiFi/RF motorized window assemblies).
[0058] Numerous specific details are set forth in order to provide a thorough understanding of embodiments of the present invention. It will be apparent, however, to one skilled in the art that embodiments of the present invention may be practiced without some of these specific details. In other instances, well-known structures and devices are shown in block diagram form.
[0059] Embodiments of the present invention include various steps. The steps may be performed by hardware components or may be embodied in machine-executable instructions, which may be used to cause a general-purpose or special-purpose processor programmed with the instructions to perform the steps. Alternatively, the steps may be performed by a combination of hardware, software and/or firmware.
[0060] Embodiments of the present invention may be provided as a computer program product, which may include a machine-readable medium having stored thereon instructions, which may be used to program a computer (or other electronic devices) to perform a process. The machine-readable medium may include, but is not limited to, floppy diskettes, optical disks, compact disc read-only memories (CD-ROMs), and magneto-optical disks, ROMs, random access memories (RAMs), erasable programmable read-only memories (EPROMs), electrically erasable programmable read-only memories (EEPROMs), field programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), magnetic or optical cards, flash memory, or other type of media/machine-readable medium suitable for storing electronic instructions.
[0061] Moreover, embodiments of the present invention may also be downloaded as a computer program product or data to be used by a computer program product, wherein the program, data, and/or instructions may be transferred from a remote computer to a requesting computer by way of data signals embodied in a carrier wave or other propagation medium via a communication link (e.g., a modem or network connection). For other parts of the program, data, or instructions, this communication link may include external networks such as the telephony network (e.g., Public Switched Telephony Network, cellular, WiFi, and other voice and wireless networks) and/or the internet. In some cases, the communications link may be comprised of multiple networks, even multiple heterogeneous networks, such as one or more border networks, voice networks, broadband networks, service provider networks, Internet Service Provider (ISP) networks, and/or Public Switched Telephone Networks (PSTNs), interconnected via gateways operable to facilitate communications between and among the various networks.
CONCLUSION
[0062] In conclusion, the present invention provides novel apparatuses, methods, and arrangements for a motorized window covering holder. While detailed descriptions of one or more embodiments of the invention have been given above, various alternatives, modifications, and equivalents will be apparent to those skilled in the art without varying from the spirit of the invention. For example, while the embodiments described above refer to particular features, the scope of this invention also includes embodiments having different combinations of features and embodiments that do not include all of the described features. Accordingly, the scope of the present invention is intended to embrace all such alternatives, modifications, and variations as fall within the scope of the claims, together with all equivalents thereof. Therefore, the above description should not be taken as limiting the scope of the invention, which is defined by the appended claims.
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Various embodiments relate to apparatuses and methods of attractive, low cost, controllable, or other featured motorized window covering assemblies. The use of a motor assembly with an integrated WiFi interface enables eliminating a setup box, resulting in lower cost. Eliminating the setup box and any associated wires further eliminates the eye sore that they may pose. These eliminations, along with an elongated motor assembly used in some embodiments, further enable the motor to be made less noticeable by, for example, making it easier to hide or camouflage. As one example, an elongated motor assembly, comprising an elongated casing surrounding the motor and the control board, is hidden inside a window covering holder. An IP address can be assigned to each motor, which enables addressing and controlling each motor individually from any remote device located anywhere with access to the internet.
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RELATED APPLICATIONS
This application claims priority of U.S. Provisional Patent Application No. 60/354,816 filed Feb. 6, 2002, which is incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to devices for collecting atmospheric water with a super absorbent polymer and, more particularly, to devices with particular applications in dehumidification, fog dispersal, water retrieval, pollution control, and military applications.
BACKGROUND OF THE INVENTION
Atmospheric moisture represents a peril and a resource. Fog represents a navigation hazard, and dehumidification of living space represents a considerable energy consumption component of air conditioning. Yet, in arid conditions, dew condensation represents one of the few reliable water resources. Additionally, in rural areas where arsenic and other undesirable minerals occur in well water, or in other areas where potable water is not readily available, humidity represents a clean and sustainable water supply.
While the prior art details numerous processes for removing atmospheric moisture, all of these processes suffer one or more limitations that preclude widespread feasibility. Cooling of air is a well known method to reduce the dew point and thereby condense atmospheric moisture, yet equipment and energy intensive. Alternatively, passive dew condensing traps are labor intensive to prepare and are inefficient in collecting condensate. Thus there exists a need for a device able to absorb large quantities of atmospheric moisture and to release the resulting water in a strong response to external stimuli.
Agriculture operations, particularly cattle, hog, and poultry feeding operations, produce large amounts of manure that, when processed by means of lagoons, present social and health concerns. Similar situations occur and exist in canning, manufacturing, and other industries. There is a need for a device that can be used in a manure management program to absorb and collect the atmospheric moisture and dissolved odorous substances, some of which can be recycled, that present social and health concerns. This device can be similarly used in other industrial and commercial situations.
This invention has military application for use in refugee care, water supply, and human waste pollution control, humidity control in tents, and aid to air conditioning in medical facilities and field hospitals.
This invention has application for military personnel, in field conditions, for use in supplemental water supply for equipment care and maintenance, and human needs, and latrine operation and pollution control.
SUMMARY OF THE INVENTION
A device for absorbing atmospheric moisture includes a support member with a net extending therefrom. The net includes a super absorbent polymer that has the property of being able to absorb a multiple of the polymer mass in atmospheric water and to thereafter release the water in response to an external stimulus. The device is in this way reusable. The device has particular application in the clearing of fog, manure odor clearance, and collection of potable water in remote locations.
A process for extracting atmospheric moisture is also detailed that includes the step of extending a super absorbent polymer net into contact with an atmosphere. Thereafter, with that being in contact with the atmosphere for a sufficient amount of time moisture is absorbed from the atmosphere. The application of a stimulus to the super absorbent polymer containing atmospheric moisture causes the release of liquid water therefrom. The super absorbent polymer is then suitable for reuse to again absorb atmospheric water.
BRIEF DESCRIPTION OF THE INVENTION
A better understanding of the present invention will be had upon reference to the following detailed description when read in conjunction with the accompanying drawing, wherein like reference characters refer to like parts throughout the several views, and in which:
FIG. 1 illustrates an atmospheric absorbing device according to the present invention;
FIG. 2 illustrates an atmospheric absorbing device embodiment suited for use as a room dehumidifier; and
FIG. 3 illustrates an atmospheric absorbing device embodiment suited for use as a pollution control tool in a manure management program.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention has utility in absorbing atmospheric moisture with a super absorbent polymer having the property of being able to absorb a multiple of the super absorbent polymer mass of atmospheric water and to release this water in response to external stimuli. A water swellable super absorbent polymer as described herein is a synthetic or natural polymer. Super absorbent polymers and optional matrices therefor are detailed in U.S. Pat. No. 6,051,317 which is incorporated herein by reference.
Grain sizes for super absorbent polymer particles range from 0.1 micron to 20,000 microns. Preferably, super absorbent particles are used in the range from 1 micron to 5,000 microns, and more preferably, from 50 to 1,000 microns.
This invention employs super absorbent polymer placed in nets or sheets hung to passively absorb atmospheric moisture. This collected water may then be retrieved from the polymer. The retrieved water may be discarded or used depending on the application. Various specific embodiments are described in detail: room dehumidifier, fog dispersal, water retrieval, and a manure management tool, and military applications; however, these specific embodiments in no way are meant to limit the scope of the invention.
Referring now to FIG. 1 , a device 10 is detailed having at least one mounting post 1 braced to support a super absorbent polymer net 2 . Typically two vertical posts are used and a net 2 suspended therebetween on suspension cable 14 by snap hooks 15 and net pulley 3 , after being raised into position by means of pulley rope 4 .
The posts 1 are typically 4 to 20 feet in height and spaced according to the load strength of the net 2 when fully loaded with atmospheric water. The net 2 is preferably in the form of a cargo net structure with ropes of hollow tubes of water-permeable cloth filled in isolated sections with super absorbent polymer beads and or gel therein. The tubes are mounted vertically within a frame of conventional rope. Preferably, the isolated sections are between 3 and 24 inches in length, more preferably the tubes are spaced from 1 inch to 12 inches apart, typical area being defined by a conventional rope frame is anywhere from 1 to 200 square feet. It is appreciated that such a frame can be scaled to nearly any size based upon mechanical weight bearing properties of construction components and expected atmospheric moisture content and environmental conditions.
The base trough 13 is located below the net 2 to collect loaded water within the net 2 after it is released therefrom by application of an external stimulus by stimuli applicator 11 . The base trough 13 has a swivel drain pipe 17 to facilitate removal of the water.
Preferably, the frame is selectively extended from post 1 to collect atmospheric moisture through the use of the pulley wheel 3 attached to a cable 4 and the crank 5 . It is appreciated that a selectively deployable super absorbent polymer net will have a greater serviceable lifetime if stored when not in use. In order to afford greater rigidity, preferably a frame 7 is affixed to a base trough 13 to support the net 2 in an undeployed position. More preferably, the base trough 13 is mechanically coupled to the selective frame extension system including the pulley wheel 3 , cable 4 and the crank 5 . It is appreciated that a selective frame extension according to the present invention is in the form of any conventional system illustratively including an electric winch, a telescoping post, a cantilevered rail and extendible wheel for bridge use, retractable tethered helium balloons for park authority establishing remote wildlife drinking ponds. Still more preferably, a second bottom slat 9 is attached to the bottom frame during extension.
A liquid trough 13 is located below the net 2 when in an extended position. The trough 13 extends the length of the frame 7 to collect water within the net 2 after it is released therefrom by application of an external stimulus. Preferably, the liquid trough has a swivel drain pipe 17 in order to facilitate removal of released water from the net 2 that has collected in the trough 13 .
The moisture absorbent device as detailed herein has application in a fog dispelling embodiment. For a highway fog pocket situation, an inventive device as detailed herein is mounted on a flatbed truck base 16 , suspended from guardrail posts or devoted use posts in locations where fog is known to regularly occur. It is appreciated that the inventive device is readily coupled to wireless communication technology to remotely activate the inventive device. Remote activation requires the addition of an antenna receiver and conventional automated operation components relating to extension and recycle (not shown). Power to operate a remotely activated device is supplied from line voltage, solar, wind, or other available power sources. In operation an inventive device is assembled at a selected location. The super absorbent polymer net upon exposure to moisture in a fogged area becomes engorged with the atmospheric moisture thereby increasing significantly in weight. The increased weight associated with the engorged net triggers a stimulus applicator thereby inducing release of water from the net. Preferably, the stimulus applicator is then reset and the cycle of water loading and discharge repeat automatically. It is appreciated that the device materials other than the super absorbent polymer are constructed of a variety of materials illustratively including wood, metal, and plastic consistent with water quality, cost, and local material availability conditions.
In another application, the inventive device is used at airports and other large area situations. Through the strategic placement of inventive devices as described above, the atmosphere in the vicinity of the inventive device becomes too dry to support fog formation. As a result, a comparatively dry pocket of air is formed. A dry pocket extends into a fogged area and absorbs additional atmospheric moisture thereby diluting the fog. As the engorgement and release of liquid water continues from the inventive device, dilution of the fog in adjacent areas continues thereby decreasing fog thickness and enhancing ground visibility. The rate of fog thinning with the inventive device depends on several factors illustratively including the size of the device, the placement and number of inventive devices deployed, terrain, topography, temperature, wind speed and direction, and humidity.
In another embodiment, the inventive device is operative as a room dehumidifier. Referring now to FIG. 2 a trough-shaped base 21 is supported above a floor F on legs 22 with optional height adjusters 23 . Inside the base 21 is a support block 24 for the ends of a curtain winding rod 26 . The support block 24 also secures two curtain support rods 28 . Preferably, the base 21 has a slight angle, and a swivel drain tube 30 is attached thereto. The base 21 is typically constructed of materials illustratively including wood, metal, and plastic. The curtain 34 has a bottom edge 36 that is attached to the curtain winding rod 26 . The bottom end of the curtain rod 34 fits into block 24 inside the base 21 . The curtain support rods 28 encompass the curtain 34 . The curtain rod 26 is secured to support rods 28 by angle post lock brackets 40 . Preferably the curtain rod 26 has a hook 42 adapted to engage the curtain 34 . The curtain 34 in a typical configuration includes one inch diameter hollow tubes of water permeable cloth fitted in isolated sections with super absorbent polymer beads or gel. Tubes are spaced vertically. More preferably, the tubes are affixed to a continuous sheet of water permeable cloth.
Additional reinforcement members (not shown) are provided based upon the polymer water absorbing capability and structural properties of device components elements. Preferably, the top edge 50 of the curtain 34 includes at least one loop 52 adapted to engage the hook 42 of the rod 26 .
A stimulus applicator 54 is affixed to the rod 26 and activated by the curtain attaining a preselected water weight. The stimulus applicator 54 is appreciated to operate and reset either automatically or manually.
In still another application, a super absorbent polymer net as described herein is suspended in a louvered structure, attached or built as part of a structure to provide a mist spring of potable water. In this application, a housing is provided to protect the super absorbent polymer net associated apparatus from wildlife contamination. In such an application, a released water collection base has an inner lining of plastic or stainless steel to facilitate cleaning and maintenance of sanitary conditions. It is appreciated that device materials other than the super absorbent polymer are constructed of materials illustratively including wood, metal, and plastic consistent with water quality, cost, and local material available conditions. An automatic stimulus applicator provided with the inventive device is preferably utilized to deliver released water at user specified intervals under a variety of humidity conditions. It is appreciated that the instant device is readily operated absent external line power and is well suited for rural and remote environment uses.
FIG. 3 illustrates an atmospheric moisture absorbing device embodiment well suited for use as an odor reducing and urea recovery manure management tool.
Referring now to FIG. 3 , a device shown generally at 60 is detailed having at least one mounting post 61 braced to support a super absorbent polymer net 62 . Typically two vertical posts 61 on each side on the manure lagoon M and two nets, net 62 supported therebetween across the manure lagoon M.
A cover support post 63 is located on each side of the manure lagoon M to support and anchor the cover 69 .
Three metal post holes 64 are located on each side of the manure lagoon M to locate and engage the mounting posts 61 and the cover support posts 63 .
A liquid trough 74 is located below each net 62 and is angled slightly to drain into liquid manifold 65 .
Liquid manifold 65 is located at the lower end of liquid troughs 74 and collects and directs the liquid beyond the edge of the manure lagoon M for disposal.
Support cable 67 supports net 62 through support straps 66 and liquid trough 74 and liquid manifold 65 .
Cover cable 68 supports and anchors plastic cover 69 .
Stimuli applicator 70 is mounted on mounting posts 61 for each net 62 .
On each side of the manure lagoon M located 2 feet from the side, 3 metal post holes are inserted typically 4 feet into the ground at points typically 8 feet, 14 feet, and 22 feet from the end of the lagoon M. Two mounting posts 61 and one cover support post 63 are installed in the metal post holes 8 feet, 14 feet, and 22 feet, respectively, on each side of the manure lagoon M.
Support cable 67 extends horizontally across the manure lagoon M from about one foot below the top of each mounting post 61 . Super absorbent polymer net 62 and liquid trough 74 and liquid manifold 65 are suspended from support cable 67 . Mounting post 61 typically is about 14 feet in length, cover support post 63 typically is about 12 feet in length, and metal post hole 64 typically is about 4 feet in length. Plastic cover 69 is supported and anchored by cover cable 68 .
This device has application in manure management programs of large dairy, beef, pork, and poultry operations.
The stimulus applied herein to release water from an engorged super absorbent polymer illustratively includes pH change or protonation/deprotonation as detailed in Department of Energy, Office of Science—Feature Article May 7, 2001 Polymer Improvements, which is incorporated herein by reference.
While the forms of the invention herein described constitute presently preferred embodiments, many others are possible. It is not intended herein to mention all the possible equivalent forms or ramifications of the invention. It is understood that the terms used herein are merely descriptive rather than limiting and various changes may be made without departing from the spirit or scope of the invention. Such changes will be apparent to one skilled in the art.
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A device for absorbing atmospheric moisture includes a support member with a net extending therefrom. The net includes a super absorbent polymer that has the property of being able to absorb a multiple of the polymer mass in atmospheric water and to thereafter release the water in response to an external stimulus. The device is in this way reusable. The device has particular application in the clearing of fog, manure odor clearance, and collection of potable water in remote locations. A process for extracting atmospheric moisture is also detailed that includes the step of extending a super absorbent polymer net into contact with an atmosphere. Thereafter, with that being in contact with the atmosphere for a sufficient amount of time moisture is absorbed from the atmosphere. The application of a stimulus to the super absorbent polymer containing atmospheric moisture causes the release of liquid water therefrom. The super absorbent polymer is then suitable for reuse to again absorb atmospheric water.
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RELATED U.S. APPLICATION DATA
[0001] This application is a continuation of U.S. application Ser. No. 11/010,163, filed Dec. 10, 2004, now pending, which is a divisional of U.S. application Ser. No. 10/364,447, filed Feb. 11, 2003, now U.S. Pat. No. 6,829,862, which claims the benefit of U.S. Provisional Application No. 60/356,521, filed Feb. 13, 2002.
BACKGROUND OF THE INVENTION
[0002] This invention relates generally to pergolas, and more particularly to pergola end caps.
[0003] Prior art pergolas have generally been made from wood or metal. Wood and metal are adversely affected by weather, structurally and aesthetically deteriorating over time. To overcome the weather limitations of prior art materials, vinyl is becoming a popular substitute material. Vinyl provides the structural and aesthetic qualities of prior art materials with the added advantage of being nearly impervious to the effects of weather.
[0004] The vinyl components used in constructing pergola structures are pre-made rigid extrusions. Vinyl extrusions have generally hollow, rectangular shapes. End caps are required to finish protruding pergola ends. Prior art vinyl end caps have been flat pieces. Aesthetically, it is desirable to have shaped pergola ends, especially if decorative ends are desired in the pergola structure.
SUMMARY OF THE INVENTION
[0005] The present invention provides a shaped, decorative pergola vinyl end cap, a method of shaping pergola vinyl component ends, and a portable tool used for shaping pergola vinyl component ends.
[0006] These together with other objects of the invention, along with various features of novelty which characterize the invention, are pointed out with particularity in the claims annexed hereto and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated a preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a rectangular vinyl extrusion before shaping;
[0008] FIG. 2 is a rectangular vinyl extrusion after shaping;
[0009] FIG. 3 is a perspective view, partly in section, of a pergola structure.
[0010] FIG. 4 is a perspective view of a template.
[0011] FIG. 5 is a perspective view of 2×6 and 2×8 pergola end caps.
[0012] FIG. 6 is a shaped rectangular vinyl extrusion end with pergola end cap applied.
[0013] FIG. 7 is a perspective view of a 2×8 pergola end cap.
[0014] FIG. 8 is a perspective view of a 2×6 pergola end cap.
[0015] FIG. 9 is a front view of a 2×6 pergola end cap.
[0016] FIG. 10 is a rear view of a 2×6 pergola end cap.
[0017] FIG. 11 is a side view of a 2×6 pergola end cap.
[0018] FIG. 12 is a bottom view of a 2×6 pergola end cap.
[0019] FIG. 13 is a top view of a 2×6 pergola end cap.
[0020] FIG. 14 is a rear view of a 2×8 pergola end cap.
[0021] FIG. 15 is a front view of a 2×8 pergola end cap.
[0022] FIG. 16 is a side view of a 2×8 pergola end cap.
[0023] FIG. 17 is a bottom view of a 2×8 pergola end cap.
[0024] FIG. 18 is a top view of a 2×8 pergola end cap.
[0025] FIG. 19 is a front perspective view of a shaped end piece.
[0026] FIG. 20 is a rear perspective view, partly in section, of a shaped end piece.
[0027] FIG. 21 is a front perspective view of the shaped end piece attached to an extrusion end.
[0028] FIG. 22 is a front perspective view of the shaped end piece attached to an extrusion end by means of tabs.
[0029] FIG. 23 is a front perspective view of the shaped end piece attached to an extrusion end by means of an external collar.
DETAILED DESCRIPTION OF THE INVENTION
[0030] Referring to the drawings in detail wherein like elements are indicated by like numerals, there is shown a rectangular vinyl extrusion 10 before ( FIG. 1 ) and after ( FIG. 2 ) shaping. The extrusions 10 are major vinyl components used to form a pergola structure 1 . Unlike wood, vinyl pergola elements must have their shapes assembled as opposed to simple mitering. A pergola is an arbor formed of horizontal trellis work supported on columns or posts. See FIG. 3 . The pergola 1 has a trellis work “roof” 2 formed of horizontal carrying beams 3 and horizontal rafters 4 . The beams 3 are supported by vertical posts 5 . The beams 3 and rafters 4 are made from vinyl extrusions 10 with ends 11 which extend over the support posts 5 and carrying beams 3 . The extrusion ends 11 are shaped prior to being formed into the pergola structure 1 , typically by cutting with a CNC machine. Alternatively, a tool comprised of a template 50 may be fitted over the extrusion end 11 and the extrusion end 11 manually routed. See FIG. 4 . A typical router used would be a laminate trimmer-style router with a collar or bearing able to follow the outline of the invention template. Each shaped extrusion end 11 then has an end cap 30 applied. See FIG. 5 . Each end cap 30 is glued onto a shaped extrusion end 11 . See FIG. 6 . The end caps 30 may be preformed with a mold. Alternatively, a shaped end piece 60 as described in detail below may be preformed and then applied to an unshaped extrusion end 11 .
[0031] Each extrusion 10 is comprised of a first side 12 , an opposing second side 13 , a top side 14 and a bottom side 15 , said sides 12 , 13 , top side 14 and bottom side 15 defining an extrusion interior 16 . The extrusion interior 16 has one or more internal bracing walls 17 perpendicularly joined to first side 12 and second side 13 , said bracing walls 17 being parallel to said top side 14 and bottom side 15 .
[0032] The invention template 50 has a first side 52 , an opposing second side 53 , a top side 54 , an open bottom side 55 , a forward, shaped end 56 , and an open rear end 57 , said sides 52 , 53 , top side 54 , open bottom side 55 , forward shaped end 56 and open rear end 57 defining a template interior 51 . The template forward shaped end 56 may have side connectors 58 , said side connectors being elongated, narrow elements connecting said first side 52 with said second side 53 , thereby providing stiffening to the template 50 . The template 50 is slid over the extrusion 10 , template open rear end 57 over an extrusion end 11 first. The template 50 is then moved along the extrusion 10 until the top 54 of the template forward shaped end 56 is aligned with the top 14 of the extrusion end 11 . The portion of the extrusion 10 protruding 18 forward of the template forward end 56 is then cut away. This results in an extrusion 10 with a shaped end 11 ′. See FIG. 2 .
[0033] An invention end cap 30 is then applied to the shaped extrusion end 11 ′. For purposes of exposition, applicant assumes that two cross-sectional sizes of extrusions will be used, i.e., 2×6 and 2×8. A 2×6 extrusion will generally have two bracing walls 17 as shown in FIGS. 1 and 2 . A 2×8 extrusion will generally have three bracing walls 17 . Each end cap 30 has an outside, forward side 31 , an inside, rear side 32 , a top portion 33 , a bottom portion 34 , and two opposite side edges 35 . Each side edge has one or more rearwardly protruding shaped side flanges 36 . The end cap top portion 33 and bottom portion 34 each have a rectangular arrangement of rearwardly protruding flanges 37 . The rearwardly protruding flanges 36 , 37 are adapted to engage the interior portions of the extrusion sides 12 , 13 , top 14 and bottom 15 . The flanges 36 , 37 are arranged to fit between and around the bracing walls 17 . Each end cap 30 is placed against a shaped extrusion end 11 ′ wherein the end cap inside, rear side 32 is positioned against the extrusion shaped end 11 ′ and the flanges 36 into the extrusion interior 17 , said end cap top portion 33 abutting the extrusion top 14 and said end cap bottom 34 portion abutting the extrusion bottom 15 .
[0034] Referring more particularly to FIGS. 19-21 , in an alternate embodiment, a shaped end piece 60 may be preformed and then applied to an unshaped extrusion end 11 . The shaped end piece 60 has a first side 62 , an opposing second side 63 , a top side 64 , a bottom side 65 , a forward, closed, shaped end 66 , and an open rear end 67 , said sides 62 , 63 , top side 64 , bottom side 65 , forward shaped end 66 and open rear end 67 defining an end piece interior 61 . The shaped end piece forward end 66 may be formed as described above with an end cap 30 applied. The shaped end piece open rear end 67 is fitted against and joined to an unshaped extrusion end 11 as shown in FIGS. 1 and 21 . The shaped end piece 60 has a cross section dimensionally equal to the cross section of the extrusion 10 .
[0035] The shaped end piece 60 may be glued to the extrusion end 11 by means of tabs 68 protruding from the shaped rear end into the extrusion end interior 16 . See FIG. 22 . The heavy duty glue used fuses the vinyl pieces, i.e., extrusion 10 and shaped end piece 60 , together. Alternatively, the shaped end piece 60 may be joined to the extrusion end 11 by means of an external collar 69 fitted about the seam formed by the extrusion end 11 and shaped end piece rear 67 . See FIG. 23 .
[0036] It is understood that the above-described embodiment is merely illustrative of the application. Other embodiments may be readily devised by those skilled in the art which will embody the principles of the invention and fall within the spirit and scope thereof.
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A shaped, decorative pergola vinyl end cap and end piece, a method of shaping pergola vinyl component ends, and a portable tool used for shaping pergola vinyl component ends.
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This is a division of application Ser. No. 944,953, filed Jan. 5, 1987, now U.S. Pat. No. 4,760,083, which in turn is a continuation-in-part of U.S. application Ser. No. 850,015, filed Apr. 10, 1986, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to indolines and more particularly to 3,3-heterocyclic-disubstituted indolines, pharmaceutical compositions containing them, processes for preparing them and methods of using them in mammals to treat cognitive deficiencies and/or neurological function deficits and/or mood disturbances such as found, for example, in degenerative nervous system diseases.
2. Background Including Prior Art
There is a steadily growing need for effective treatment for Nervous System Disorders causing cognitive and neurological deficiencies. Many of these diseases, of which the incidence generally rises with increasing age, are due to degenerative changes in the nervous system. Although in early stages of some diseases certain systems are rather specifically affected (e.g. cholinergic systems in Alzheimer's Disease, and Myasthenia Gravis, the dopaminergic system in Parkinson's Disease, etc.), multiple neurotransmitter system deficiencies (acetylcholine, dopamine, norepinephrine, serotonin) are generally found at later stages of these diseases and are thought to exist at all stages of diseases such as senile dementia, multi-infarct dementia, Huntington's disease, mental retardation, etc. This may explain the generally observed multiple symptomatology which includes cognitive, neurological and affective/psychotic components (see Gottfries, Psychopharmacol. 86, 245, 1985). Deficits in the synthesis and release of acetylcholine in the brain are generally thought to be related to cognitive impairment (see Francis et al., New England J. Med., 313, 7, 1985) whereas neurological deficits (e.g., Parkinsonian Symptoms) and mood/mental changes may be related to impairment of dopaminergic and serotonergic systems, respectively. Other neurological deficits (e.g., Myasthenia Gravis) are related to cholinergic deficiencies in the peripheral nervous system.
Treatment strategies employed hitherto encompass vascoactive drugs like vincamine and pentoxifylline; "metabolic enhancers" like ergoloid mesylates, piracetam and naftidrofuryl; neurotransmitter precursors like 1-DOPA, choline and 5-hydroxytryptamine; transmitter metabolizing enzyme inhibitors like physostigmine; and neuropeptides like adrenocorticotropic hormone and vasopressin-related peptides. Except for 1-DOPA treatment in Parkinson's disease and cholinesterase inhibitor treatment in Myasthenia Gravis, these treatment strategies have generally failed to produce clinically significant improvements (Hollister, Drugs, 29, 483, 1985). Another strategy to treat these multiple symptoms is to enhance the residual function of the affected systems by enhancing the stimulus-induced release of neurotransmitters. Theoretically, such an enhancement would improve the signal-to-noise ratio during chemical transmission of information, thereby reducing deficits in processes related to cognition, neurological function and mood regulation.
To date, there are not many patent or literature references which describe 3,3-heterocyclic disubstituted indolines. Most pertinent, are Japanese Patent No. 55-129284, issued Oct. 6, 1980 and M. Ogata et al., Eur. J. Med. Chem-Chim. Ther., 16(4), 373-378 (1981), which describe antifungal compounds having the formula: ##STR4## wherein R is H, halogen, alkyl, or alkoxy;
R 1 is H, alkyl, aryl or acyl; and
R 2 is thienyl, or imidazole, amongst nonheterocyclic groups.
R. W. Daisley, et al. , J. Heterocyclic Chem., 19, 1913-1016, (1982), report 1-methyl-3,3-dipiperidinoindol-2-(3H)-one as product from the reaction of the corresponding (Z) or (E) 2-arylmethylidene-indol-3(2H)-one with ethyl cyanoacetate in the presence of excess piperidine. No utility for the compound is described.
Japanese Patent No. 59-98896 describes high sensitivity, high stability recording medium containing a 3,3-disubstituted-2-oxo-2,3-dihydroindole derivative of the formula shown below as a near infrared absorber. ##STR5## wherein R 1 , R 2 , same or different, are a saturated heterocyclic ring including morpholino, pyrrolidinyl, amongst others containing at least one nitrogen atom; and
R 3 is H or alkyl.
3,3-bis(morpholino)oxoindole is also disclosed in U.S. Pat. No. 4,273,860, to A. Adin, June 16, 1981 and in A. Adin, et al., Research Disclosures, 184, 446-454 (1979), as a destabilizer material in a photoinhibitor composition utilizing cobalt (111) complexes.
The above references, other than J55-129284, and M. Ogata et al., Eur. J. Med. Chem-Chim. Ther., 16(4), 373-378 (1981) all describe 3,3-disubstituted indolones wherein the heterocyclic groups are both saturated rings. In all of the above references, the heterocyclic ring is attached to the indoline by a ring nitrogen. Furthermore in the references other than J55-129284, there is no suggestion of pharmaceutical utility for these 3,3-disubstituted indolines.
SUMMARY OF THE INVENTION
It has now been found that compounds of Formula (I) enhance the stimulus-induced release of neurotransmitters, specifically acetylcholine and, in addition, dopamine and serotonin in nervous tissue and improve processes involved in learning and memorization of an active avoidance task.
More particularly, according to the present invention there is provided a pharmaceutical composition comprising a suitable pharmaceutical carrier and a therapeutically effective amount of a compound having the formula: ##STR6## wherein: p is 0 or 1;
Z is O or S;
R is C 1 -C 10 alkyl, C 3 -C 8 cycloalkyl, 2-pyridyl, 3-pyridyl, 4-pyridyl or ##STR7## V, W, X, and Y independently are H, halo, C 1 -C 3 alkyl, OR 1 , NO 2 , CF 3 , CN or NR 1 R 2 ; R 1 and R 2 independently are H or C 1 -C 3 alkyl; ##STR8## independently are 6-membered heterocyclic rings containing at least one nitrogen atom as a part of the ring optionally substituted with one substituent selected from the group C 1 -C 3 alkyl, halo, OR 1 or NR 1 R 2 ; or an N-oxide or pharmaceutically suitable acid addition salt thereof.
Also provided is a method for the treatment of a cognitive deficiency and/or neurological function deficit and/or mood/mental disturbance such as found for instance in degenerative nervous system disease in a mammal, said method comprising administering to the mammal a therapeutically effective amount of at least one of the above-described compounds of Formula (I).
Additionally provided is a novel class of compounds of Formula (I) active in treating cognitive and/or neurological deficiencies and/or mood/mental disturbances such as found, for instance in degenerative nervous system disease.
Further provided is a process for preparing a compound of Formula (I) comprising
(a) contacting an oxindole of the formula ##STR9## wherein p, X, Y, and R are as defined above, with a base; (b) contacting the product of step (a) with a compound of the formula ##STR10## wherein ##STR11## is as defined above and D is a halide, methanesulfonate, or p-toluenesulfonate;
(c) contacting the product of step (b) with a compound of the formula ##STR12## wherein ##STR13## is defined above and D is a halide, methanesulfonate, or p-toluenesulfonate; and
(d) optionally contacting the product of step (c) with Lawesson's reagent or with P 4 S 10 to prepare the thiooxindole.
PREFERRED EMBODIMENTS
Preferred compounds are those of formula (I) where:
p is 0; or
Z is O; or
X and Y are H; or
R is CH 3 , phenyl or m-chlorophenyl; or ##STR14## are each pyridyl attached by a ring carbon atom.
Specifically preferred for their ability to enhance stimulus-induced acetylcholine release are:
3,3-Bis(2-pyridylmethyl)-1-phenylindolin-2-one;
3,3-Bis(3-pyridylmethyl)-1-phenylindolin-2-one;
3,3-Bis(4-pyridylmethyl)-1-phenylindolin-2-one;
3,3-Bis(4-pyridylmethyl)-1-methylindolin-2-one;
3,3-Bis(4-pyridylmethyl)-1-(3-chlorophenyl)-indolin-2-one;
and pharmaceutically suitable acid addition salts thereof.
DETAILED DESCRIPTION OF THE INVENTION
Synthesis
Most of the oxindole compounds of this invention are prepared by the synthetic sequence represented by Scheme 1. ##STR15## X, Y, p, R, ##STR16## are as defined above, D represents a displaceable group such as halogen (I, Br, Cl, or F) or methanesulfonate or p-toluenesulfonate. These reactions result from formation of an anion at the 3-position of the oxindole of Formula (II) by reaction of the oxindole with a suitable base followed by displacement of D by the anion and formation of the 3-mono-substituted compound (III). This mono-substituted product (III) can then either be isolated prior to the next step or, preferably, especially when ##STR17## are the same, treated again with another equivalent of base without prior isolation, to give the 3,3-disubstituted oxindole (IV).
Suitable bases for forming the anion include sodamide, lithium diisopropylamide, sodium hydride, potassium tert-butoxide, sodium alkoxide, potassium alkoxide, lithium alkoxide, potassium hydride, lithium 2,2,6,6-tetramethylpiperidide, butyl lithium, sec-butyl lithium, tert-butyl lithium, and lithium, sodium or potassium hexamethyldisilazide. The reaction is run in an aprotic solvent, generally in an ether such as diethylether, glyme, tetrahydrofuran or dioxane. However, if the oxindole is soluble in a nonpolar solvent, the reaction may be run in a hydrocarbon such as hexane, heptane, cyclohexane, methylcyclohexane, benzene or toluene.
In running the reaction, the oxindole is dissolved in an appropriate solvent, and, depending upon the strength of the base, the solution is cooled to a temperature between -40° C. and room temperature. When a more reactive base such as lithium diisopropylamide (LDA) is used, the solution is cooled to a temperature of -30° C. and a solution of the LDA in an appropriate solvent, such as tetrahydrofuran, is added dropwise over a period of 15 minutes to one hour, while maintaining the temperature at approximately -30° C.
If one chooses to use sodamide instead of LDA, benzene is the preferred solvent. The sodamide is added to a solution of the indolinone in benzene at room temperature. In order to drive the reaction to completion, the solution is refluxed until ammonia can no longer be detected evolving from the reaction.
A solution of the electrophile ##STR18## is then added to the indolinone anion. Again, if a very reactive base such as LDA is used to generate the anion, the reaction is cooled to -30° C. and the electrophile is added dropwise. If a less active base is used to generate the anion, the electrophile is added at a temperature between 0° C. and room temperature and then the reaction mixture is refluxed.
The bisubstituted product (IV) can be prepared by generation of a second anion at the three position of the indolinone. The anion formation followed by alkylation can be done in the same manner as described above for the preparation of a mono-substituted compound of Formula (III).
Instead of running the reaction sequentially, one may at times, add two equivalents of base to the indolinone, followed by two to three equivalents of the alkylating agent. In some cases, especially those where ##STR19## it may be convenient to accomplish alkylation of the oxindole under phase transfer conditions, e.g., using a base such as sodium hydroxide dissolved in water, a water immiscible solvent such as benzene or toluene, a phase transfer catalyst such as benzyltriethylammonium chloride and two molar equivalents of the alkylating agent ##STR20## Under such conditions, vigorous stirring and elevated reaction temperatures, e.g., 60°-80° C., may facilitate conversion to the 3,3-dialkylated oxindole.
When the reaction is complete as evidenced by thin layer chromatography, excess anion is decomposed with saturated ammonium chloride solution, and the reaction is taken through an acid-base cycle to remove neutral starting materials. Purification of the basic product generally involves conventional purification techniques such as flash chromatography followed by recrystallization if necessary. The pure base (one spot on thin layer chromatography and analytical HPLC) is converted to the dihydrochloride by adding a slight excess of 25% hydrochloric acid in a solvent such as ethanol. Generally, adding an equal volume of acetone to the boiling solution affords a crop of pure colorless crystals upon cooling. Other methods that will be obvious to one skilled in the art can be used to obtain a crystalline product. The hydrochloride salt can be recrystallized from isopropanol, 1-propanol, ethanol, 95% ethanol, methanol, or mixtures of an alcohol with acetone, ethyl acetate, isopropyl acetate, or acetonitrile.
The hydrochloride salt can be converted to the corresponding free base by treatment with an inorganic base, e.g., sodium hydroxide, potassium hydroxide, sodium phosphate, ammonium hydroxide, or potassium carbonate, and then can be taken up in an organic solvent such as methylene chloride, ether, or ethyl acetate, and reprecipitated as a salt with some other pharmacologically acceptable acid such as maleic acid, methanesulfonic acid, napthalene-2-sulfonic acid, tartaric acid, hydrogen bromide, etc.
Alternatively, thallium (I) ethoxide can be used as the base as illustrated by Scheme 2. The indolinone is dissolved in a suitable solvent, preferably warm benzene, and an equimolar quantity of thallium (I) ethoxide is added rapidly to it. The organothallium compound (V) which precipitates out as a poisonous, yellowish, crystalline stable solid, is filtered affording the thallium compound in yields of 85-95%. Care must be exercised in handling thallium compounds because of their toxicity. ##STR21##
Organothallium compounds generally react with electrophiles to form the monoalkylated products. However, with very reactive electrophiles such as picolyl chlorides, benzyl bromide or the like, the 3,3-bis-alkylated products are obtained, as shown in Scheme 2, and as is exemplified by Example 1.
The thallium indoline (V) is heated with an electrophile such as picolyl chloride in an inert solvent, such as benzene or toluene, at 30° C. to the boiling point of the solvent, for several hours to 24 hours. Preferred is a temperature of 80° C. for 24 hours. When the reaction is complete as indicated by thin layer chromatography and the precipitated thallium chloride is filtered off, the remaining organic solution is taken through an acid-base cycle and purification, and optional shift formation is carried out as described above.
Preparation of the starting oxindole (II) represented in Scheme I and Scheme 2 can be carried out by one or more of a large number of general synthetic methods described in the chemical literature. For instance the reaction of an N-substituted aniline (VI) with chloroacetyl chloride to form an amide (VII) is a well known reaction. This is illustrated in Scheme 3. ##STR22##
Requisite diarylamine syntheses (VI; where p=0, R=substituted phenyl) are widely known in the chemical literature. Many involve conversion of N-arylphenyl-enediamine by diazotization and for example Sandmeyer reaction with the appropriate substituted diarylamine. Again, one skilled in the art of organic synthesis can select a suitable synthesis for preparation of the appropriate diarylamine required to extend the Examples to the related compound of this invention. Recent useful syntheses include those described by Katritzsky et al., J. Chem Soc., Perkin. Trans. I, 2611 (1983), Gorwin et al., Chem. Commun., 4, 238 (1985), and Malz et al. in U.S. Pat. No. 4,431,841A (1984).
Other N-substituted anilines (VI; where p=1) can be made by conventional synthetic methods commonly used in organic chemistry, e.g., by reaction of a suitable carboxylic acid chloride with an aniline to afford an amide which is then reduced by lithium aluminum hydride or diborane in tetrahydrofuran at about 67° C. to afford the N-substituted aniline (V1), as depicted in Scheme 4 below. ##STR23##
The starting oxindole (II) can then be prepared by Friedel-Crafts ring closure of an amide of Formula (VII) in the presence of a Lewis acid such as aluminum chloride (AlCl 3 ). Other Lewis acids such as tin tetrachloride (SnCl 4 ) or boron trifluoride (BF 3 ) can be used depending on the chemical structure of the amide (VII). Choice of solvent if any is dependent on the actual compound of Formula (VII) to be cyclized and on the Lewis acid used. Nitrobenzene, tetrachloroethane, ethylene dichloride and methylene chloride are often used as solvents. Generally, the use of AlCl 3 without a solvent is preferred.
If substituents X and Y are electron withdrawing and deactivate the aromatic ring to which they are attached towards electrophilic substitution and if V and W are electron donating or activate the ring (where R is substituted phenyl) other methods may be more convenient for synthesis of oxindoles (II). These methods will be known to one skilled in the art of organic synthesis who is familiar with the literature of oxindole synthesis.
For example, in addition to the Friedel-Crafts cycloalkylation illustrated by Scheme 2, X and Y substituted oxindoles can be made by the general "azasulfonium ion" rearrangement methods of Gassman [U.S. Pat. Nos. 3,897,451 (1975), 3,996,264 (1976), and 3,972,894 (1976); see also J. Am. Chem. Soc., 96, 5512 (1974) etc.] or in some instances from o-nitrophenyl acetic acid [see Walker, J. Am. Chem. Soc., 77, 3544 (1955) and Hardigger et al., Helv. Chim. Acta., 39, 514 (1956)].
Other more direct synthesis of 3,3-disubstituted 2-oxindoles can be carried out by use of the Brunner reaction of N-arylhydrazides [Org. Synthesis, 37, 60 (1957); Rohrscheidt et al., Liebigs Ann. Chem., 680 (1978)] and by processes involving direct oxidation of substituted indoles [Lawson et al., J. Org. Chem., 26, 263 (1961); R. L. Hinman et al., ibid, 29, 1206 (1964); Lawson et al., J. Am. Chem. Soc., 82, 5918 (1960); Szabo-Pusztag et al., Synthesis, 276 (1979). Other methods for making oxindoles are described by A. P. Kozikowski, et al., J. Am. Chen. Soc., 43 (10), 2083 (1978); T. Nakashima, et al., Chem. Pharma. Bull., 17 (11), 2293 (1969); Y. Tamura, et al., Synthesis, 534 (1981); J. F. Bunnett, J. Org. Chem., 28 (1), 1 (1963); R. R. Goehring, J. Am. Chem. Soc., 107 (z), 435 (1985); T. Hamada, et. al., Chem. Pharm. Bull., 29 (1), 128 (1981); D. Ben-Ishai, et al., Tet. Lett., 21 (6), 569-72 (1980); J. F. Wolfe, J. Am. Chem. Soc., 102 (10), 3646 (1980); J. G. Atkinson, Tet. Lett., (31), 3857 (1979); M. Mori, et al., Tet. Lett., (21) 1807 (1976); P. Parimoo, Indian J. Chem., 10 (17), 764 (1972); D. Klamann, et al., Chem Ber., 100 (6), 1870 (1967)].
This bibliographic list is intended to be illustrative of the great variety of methods available to make the 2-oxindole intermediates useful in this invention.
The 2-thiooxindoles (VIII) of this invention can be made by reaction of the oxindoles with Lawesson's reagent or with phosphorus pentasulfide (P 4 S 10 ) as is illustrated in Scheme 5. ##STR24##
Lawesson reagent is 2,4-bis(4-methoxyphenyl)-1,3-dithia-2,4-diphosphetane-2,4-disulfide. Its use in the thiation of carboxamides and lactams is well known, as is the use of phosphorus pentasulfite for similar reactions. The reactions are customarily carried out in methylene chloride, benzene, acetonitrile, or piperidine depending on the solvent power and reaction temperature required for the particular oxindole involved. Usually the P 4 S 10 works better if it is first purified by extraction into methylene chloride by Soxhlet extraction. Ordinarily thiation reactions can be carried out at mild temperatures (25°-80° C.) and the products can be isolated by chromatography or crystallization.
The nitrogen-containing heterocyclic compounds ##STR25## used as intermediates in Schemes 1 and 2 are available by methods described in standard works on heterocyclic chemistry such as Katritzsky and Rees, Comprehensive Heterocyclic Chemistry, Vols. 2-5, Pergamon Press, N.Y., 1984. In some instances the preparation of the corresponding hydroxy compounds (D=OH) is described in the literature; these can be converted to the corresponding halo compounds (e.g. D=Br) for the alkylation reaction indicated in Schemes 1 and 2 by mild reagent (such as Ph 3 P, CBr 4 ). Alternatively the hydroxy compounds can be converted to the corresponding sulfonate esters (e.g. D=CH 3 SO 2 O) by reaction with the corresponding sulfonylchloride in the presence of pyridine or triethylamine at cold temperatures. Generally, temperatures of about 0° C. to -20° C. are preferred for formation of these sulfonates.
The compounds useful in the present invention can be used as their free base or their pharmaceutically suitable salts. Salt formation is well known to those skilled in the art.
The invention can be further understood by the following examples in which parts and percentages are by weight unless otherwise indicated; all temperatures are in degrees centigrade.
EXAMPLE 1
3,3-Bis(2-pyridylmethyl)-1-phenylindolin-2-one
To a solution of 0.1 mole of N-phenylindolin-2-one in 200 ml of benzene under N 2 was rapidly added 0.1 mole of thallium ethoxide. The solution was heated briefly to boiling. At about 50°, a heavy precipitate started to form. After refluxing for 5 minutes, the mixture was cooled and 200-300 ml of hexane was added to complete precipitation. The solid was filtered off and dried to yield 85% of the thallium salt of N-phenylindolin-2-one as a yellow solid.
0.22 Mole of picolylchloride hydrochloride was carefully converted to the free base by dissolving in 30 ml cold water, cooling to 0°-5° and basifying with ammonium hydroxide. The free base was extracted out (3×100 ml benzene), dried with Na 2 SO 4 and filtered, while maintaining the temperature no higher than 10°.
To this solution was added the thallium salt of the N-phenylindolin-2-one, followed by 200 ml benzene. This mixture was refluxed overnight and after cooling, the precipitated thallium chloride was filtered off. The basic product was extracted out of the filtrate with 0.5N hydrochloric acid and was then reconverted to the base with ammonium hydroxide and extracted into methylene chloride, dried with anhydrous potassium carbonate, filtered and evaporated. The remaining thick dark red oil was dissolved in 50 ml ether and trituration with a glass rod started crystallization, which was complete in a short while. The solid was filtered off, washed with ether and dried to yield 11.2 g of product; m.p. 107°-111°. The product was purified by flash chromatography using 40-60 micron silica gel 60 (E. Merck) on a column 10" long×2" in diameter. Elution with 95:5 methylene chloride-methanol (detection with a 256 μm Gow-Max detector) afforded 8.2 g of pure free base in fractions 5 through 10 (100 ml each), R f 0.33 (silica gel; 95:5 methylene chloride/methanol); m.p. 129°-130°.
Anal. Calcd. for C 26 H 21 N 3 O: C, 79.77; H, 5.41; N, 10.73. Found C, 80.05; H, 5.65; N, 10.67.
EXAMPLE 2
3,3-Bis(2-pyridylmethyl)-1-phenylindolin-2-one dihydrochloride
8.2 g of 3,3-Bis(2-pyridylmethyl)-1-phenylindolin-2-one was converted to the dihydrochloride salt by dissolving it in 25 ml methylene chloride and adding 25 ml of 25% hydrochloric acid in ethanol. The solution was evaporated and the glassy residue was dissolved in 75 ml boiling acetone. Cooling to room temperature and trituration started crystallization. After sitting at room temperature for 6 hours, the mixture was kept at 0° overnight. The product was then filtered, washed with cold acetone and dried in a vacuum oven for 1 hour at 60° C. over Granusic to yield 8.55 g; m.p. 250°-251°. The product was recrystallized from isopropanol affording 8.29 g; m.p. 250°-251°.
EXAMPLE 3
3,3-Bis(3-pyridylmethyl)-1-phenylindolin-2-one dihydrochloride
To 0.3 mole of N-phenylindolinone in 300 ml of benzene was added 0.36 mole of sodamide in one batch. The mixture was refluxed for 3 hours (until ammonia evolution ceases), and the reaction was then cooled to room temperature. 0.5 Mole of 3-picolylchloride was carefully prepared from the hydrochloride salt in the same manner previously described for 2-picolylchloride and was then extracted into benzene, dried with sodium sulfate and filtered. This benzene solution of 3-picolylchloride was added dropwise with vigorous mechanical stirring to the N-phenylindolinone anion solution under nitrogen over a period of 30 minutes at 20°. After completion of addition, the reaction was refluxed for an additional 3 hours.
The reaction mixture was cooled to room temperature and a second portion of 0.36 mole of sodamide was added in one batch. As above, the mixture was refluxed until ammonia evolution from the reaction ceased (3 hours).
The reaction mixture was cooled to room temperature and an additional 0.5 mole of 3-picolylchloride base in benzene was added dropwise with vigorous stirring to the indolinone anion solution over a period of 30 minutes at 20°. After completion of addition of the 3-picolylchloride, the reaction mixture was refluxed 3 hours. The reaction mixture was then cooled in an ice bath and 1N HCl was added (300 ml) in conjunction with vigorous mechanical stirring. The HCl phase was separated and the organic phase was extracted twice more with 100 ml of 1N HCl. The combined acid extracts were made basic, extracted with methylene chloride, washed with water, dried with sodium sulfate, filtered and evaporated. The dark oil was triturated with ether to yield a crop of dense crystals, which were filtered, washed with ether until the washings were colorless, to afford 3.1 g of solid; m.p. 136.5°-138°. A portion (2.8 g) was dissolved in 10 ml of 25% hydrochloric acid in ethanol. Scratching started crystallization (dense crystals). After one hour at 0°, the white crystals were filtered off and dried to yield 3.2 g of the title compound; m.p. 156°. The product was dissolved in 115 ml boiling ethanol, to which 10 ml of boiling acetone was carefully added. The solution was allowed to cool undisturbed for 8 hours, then overnight at 0°. The pure white crystals were filtered, washed with cold 1:1 ethanol-acetone and dried under infrared lamps, to afford 2.6 g of pure product; mp 156°-156.5°.
EXAMPLE 4
3,3-Bis(4-pyridylmethyl)-1-phenylindolin-2-one dihydrochloride
N-phenylindolinone (0.05 mole) was dissolved in the minimum amount of dry tetrahydrofuran in a multi-neck flask under N 2 . Lithium diisopropylamide (0.05 mole) was weighed out in a dry box into a dropping funnel and then dry tetrahydrofuran was added to the lithium diisopropylamide to dissolve it. The dropping funnel containing the lithium diisopropylamide-tetrahydrofuran solution was sealed and removed from the dry box. The indolinone solution was cooled to -30° and the lithium diisopropylamide solution was added to it dropwise at -30° over a period of 15 minutes. After the addition, the reaction was allowed to warm to room temperature. The reaction mixture was again cooled to -30° and 4-picolylchloride (0.06 mole), which had been converted to the free base as previously described and then dissolved in 25 ml tetrahydrofuran, was added dropwise during 30 minutes at -30°.
After completion of addition, the reaction was allowed to warm to room temperature for 30 minutes. It was then cooled to -30° and the second portion of lithium diisopropylamide (0.05 mole) in tetrahydrofuran was added dropwise over a period of 15 minutes at -30°. After completion of addition, the reaction mixture was allowed to warm to room temperature as a second batch of 4-picolylchloride hydrochloride (0.06 mole) was converted to the free base.
The room temperature anion reaction mixture was again cooled to -30° and the second portion of 4-picolylchloride in 25 ml tetrahydrofuran was added dropwise over a period of 30 minutes at -30°. The reaction mixture was brought to room temperature and maintained at room temperature for 1-17 hours depending on convenience. Any remaining anion was destroyed by carefully adding 50 ml saturated ammonium chloride solution. The tetrahydrofuran was then evaporated and the residue was dissolved in methylene chloride and extracted out of the methylene chloride with 3×100 ml portions of 0.5N hydrochloric acid. The combined HCl portions were made basic (pH=12) and product extracted with (3×100 ml) methylene chloride. The methylene chloride was dried with sodium sulfate, filtered and evaporated to yield 20 g of product. Purification by chromatography in 10 g batches (40-63 μm silica gel on a column 8" long×2" diameter; eluting with: EtOAc 69.46%, Hexane 29.75%, and Et 3 N 0.79%) gave 19.2 g of the base (93%); m.p. 186.0°-186.5°.
3,3-Bis(4-pyridylmethyl)-1-phenylindolin-2-one (19 g) was converted to the dihydrochloride by treatment with 40 ml 25% hydrochloric acid in ethanol. To the mixture was added 50 ml isopropanol and the solution was heated to boiling. Boiling acetone was added until thick needles just started to form (total volume of solvents: 200-250 ml). The solution was allowed to cool to room temperature, then allowed to stand overnight at 0°. The solid was filtered and washed with cold isopropanol to yield 19.5 g (84%) of the title compound; m.p. 257°-8°. (Note: degree of drying has an effect on m.p. of the dihydrochloride; very slowly increasing the temperature of the melting point apparatus gives a melting point of 275°-276°). A second crop was obtained by evaporating the filtrate, dissolving the residue in isopropanol and adding approximately an equal volume of acetone; the mixture was allowed to sit overnight at room temperature, and then 6 hours at 0° C. to yield an additional 2.8 g, m.p. 252°-253°. Recrystallization yielded 2.4 g, of the second crop: m.p. 257°-258° C. The total dihydrochloride yield was 21.9 g (94%).
EXAMPLE 5
3,3-Bis(4-pyridylmethyl)-1-methylindolin-2-one dihydrochloride
To a solution of 0.05 mole of 1-methylindolin-2-one in 50 ml of tetrahydrofuran cooled to -30° was added 0.1 mole of lithium diisopropylamide in 100 ml of tetrahydrofuran in a dropwise fashion over 30 minutes. The reaction mixture was allowed to warm to room temperature after completion of addition, and was then cooled back down to -30°. Following the careful conditions described previously for the conversion of picolylchloride hydrochloride to picolylchloride base, 0.21 mole of 4-picolylchloride hydrochloride was converted to the anhydrous free base and was then dissolved in tetrahydrofuran (150 ml). This solution was added dropwise during 60 minutes at -30° to the reaction mixture.
After completion of addition, the reaction mixture was allowed to warm to room temperature for one hour, then was cooled and carefully decomposed by the dropwise addition of saturated ammonium chloride.
When the addition was complete, the tetrahydrofuran was evaporated and the residue was partitioned between benzene and 0.5N HCl. This residue was transferred to a separatory funnel and the organic phase was extracted twice more with 0.5N HCl. The combined acid extracts were basified, extracted with benzene, dried with Na 2 SO 4 , filtered and evaporated. The residue was triturated with ether, filtered and washed with a small amount of ether to yield 2.9 g; m.p. 149.9°-150.9°. This product was converted to the dihydrochloride salt with 25% hydrochloric acid and ethanol and crystallized from ethanol-acetone to yield 1.9 g of the title compound, m.p. 274.5°.
EXAMPLE 6
3,3-Bis(4-pyridylmethyl)-1-(3-chlorophenyl)indolin-2-one dihydrochloride
Using the procedure of Example 3, the title compound was prepared from N-(3-chlorophenyl)indolin-2-one in a yield of 24%, m.p. 275°-276° C.
EXAMPLES 7 AND 8
3,3-Bis(4-pyridylmethyl-1-oxido)-1-phenylindolin-2-one and 3-(4-pyridylmethyl)-3-(4-pyridylmethyloxido)-1-phenylindolin-2-one
A solution of 4.14 g (0.024 mole) of 80-85% m-chloroperbenzoic acid in 50 ml methylene chloride was added dropwise with magnetic stirring to 3,3-bis(4-pyridylmethyl)-1-phenylindolin-2-one in 100 ml methylene chloride, and solution was stirred overnight. Checking for peroxide with moist starch iodide paper was negative, so the methylene chloride solution was washed with 3×75 ml 5% sodium bicarbonate, dried with sodium sulfate, filtered and evaporated.
The residue was triturated with 5:1 ether/ethyl acetate to yield 2.14 g of a solid containing the bis-N-oxide, the mono-N-oxide, and a small amount of starting material. The reaction mixture was purified by flash chromatograpy (silica gel, 40-63 μm, eluting with 90:10 chloroform/methanol) affording 1.18 g, of the major product, R f =0.34; m.p. 265.3°-265.7° (after recrystallization from 10 ml water). The high resolution mass spectrum confirmed the major product as the bis N-oxide; m/e 423.1595 (M+, calcd. for C 26 H 21 N 3 O 3 423.1582).
A second fraction (200 mg) obtained from the flash chromatography was identified as the mono-N-oxide; 3-(4-pyridylmethyl)-3-(4-pyridylmethyloxido)-1-phenylindolin-2-one, R f =0.41; m.p. 217°-7°-218.5°.
Mass spectrum m/e 407.1631 (M+, calcd. for C 26 H 21 N 3 O 2 407.1634).
The compounds of Examples 1-8, and other compounds which can be prepared by such procedures and procedures described in the synthesis disclosure are illustrated by the structures represented in Table 1. This Table is intended to illustrate the invention, but not to limit its breadth.
TABLE 1 ##STR26## Ex. No. X Y R V W p ○H ○H' Z m.p. °C. 1 H H ##STR27## H H 0 ##STR28## ##STR29## O 129-130 2 H H ##STR30## H H 0 ##STR31## ##STR32## O 250-251(2 HCl) 3 H H ##STR33## H H 0 ##STR34## ##STR35## O 156-156.5(2 HCl)136.5-138(free base) 4 H H ##STR36## H H 0 ##STR37## ##STR38## O 257-258(2 HCl)186-186.5(free base) 5 H H CH.sub.3 -- -- 0 ##STR39## ##STR40## O 274-275(2 HCl)149.5-150.9(free base) 6 H H ##STR41## 3-Cl H 0 ##STR42## ##STR43## O 275-276(2 HCl) 7 H H ##STR44## H H 0 ##STR45## ##STR46## O 265.3-265.7 8 H H ##STR47## H H 0 ##STR48## ##STR49## O 217.7-218.5 9 H H ##STR50## -- -- 1 ##STR51## ##STR52## O 173-174(3 HCl) 10 H H ##STR53## H H 0 ##STR54## ##STR55## O 196.1-196.7 11 H H ##STR56## H H 0 ##STR57## ##STR58## O 201.7-202.0 12 H H ##STR59## H H 0 ##STR60## ##STR61## O Amorphous 13 H H ##STR62## H H 0 ##STR63## ##STR64## O Amorphous 14 H H ##STR65## H H 0 ##STR66## ##STR67## S 15 H H ##STR68## H H 0 ##STR69## ##STR70## O 230.8-231.4 16 H H CH.sub.3 CH.sub.2 CH.sub.2 -- -- 0 ##STR71## ##STR72## O 227-228(2 HCl) 17 H H ##STR73## H H 0 ##STR74## ##STR75## O 18 H H ##STR76## H H 0 ##STR77## ##STR78## O 19 6-CH.sub.3 H ##STR79## H H 0 ##STR80## ##STR81## O 217-219 20 6-OCH.sub.3 H ##STR82## H H 0 ##STR83## ##STR84## O 21 5-Cl H ##STR85## H H 0 ##STR86## ##STR87## O 22 H H S -- -- 0 ##STR88## ##STR89## O 23 H H ##STR90## H H 1 ##STR91## ##STR92## O 24 H H C.sub.2 H.sub.5 -- -- 0 ##STR93## ##STR94## O 25 H 7-NHC.sub.3 H.sub.7 ##STR95## H H 0 ##STR96## ##STR97## O 26 H H ##STR98## H H 0 ##STR99## ##STR100## S 27 H H ##STR101## 4-OCH.sub.3 3-OCH.sub.3 0 ##STR102## ##STR103## O 28 5-OCH.sub.3 6-OCH.sub.3 ##STR104## H H 0 ##STR105## ##STR106## O 29 H H ##STR107## 3-Cl 4-Cl 1 ##STR108## ##STR109## O 30 H H ##STR110## -- -- 1 ##STR111## ##STR112## O 31 H H ##STR113## 2-NO.sub.2 H 0 ##STR114## ##STR115## O 32 H H n-C.sub.10 H.sub.21 -- -- 1 ##STR116## ##STR117## O 33 5-CH.sub.3 4-CH.sub.3 ##STR118## H H 0 ##STR119## ##STR120## S 34 4-NO.sub.2 H ##STR121## -- -- 1 ##STR122## ##STR123## O 35 4-N(CH.sub.3).sub.2 H ##STR124## H 4-CF.sub.3 0 ##STR125## ##STR126## O 36 H H ##STR127## H 4-CN 0 ##STR128## ##STR129## O 37 H H ##STR130## H 4-CF.sub.3 1 ##STR131## ##STR132## O 38 H H ##STR133## H 3-N(C.sub.2 H.sub.5).sub.2 0 ##STR134## ##STR135## O 39 H H ##STR136## H H 0 ##STR137## ##STR138## S 40 H H ##STR139## 3-Cl 4-Cl 0 ##STR140## ##STR141## O 41 H 4-CF.sub.3 ##STR142## H H 0 ##STR143## ##STR144## O 42 ##STR145## H ##STR146## -- -- 1 ##STR147## ##STR148## O 43 H H ##STR149## H H 0 ##STR150## ##STR151## O 167.5-169 44 H H ##STR152## 3-NO.sub.2 H 0 ##STR153## ##STR154## S 45 H H ##STR155## H H 0 ##STR156## ##STR157## O 123-124 46 H H ##STR158## H H 0 ##STR159## ##STR160## O 152 47 H H ##STR161## 4-CN H 0 ##STR162## ##STR163## O 48 5-OC.sub.2 H.sub.5 H ##STR164## H H 0 ##STR165## ##STR166## O 49 H H ##STR167## H H 0 ##STR168## ##STR169## O 233-235 50 H H ##STR170## H H 0 ##STR171## ##STR172## O 51 H H ##STR173## H H 0 ##STR174## ##STR175## O 52 H H ##STR176## H H 0 ##STR177## ##STR178## O 53 H H ##STR179## H H 0 ##STR180## ##STR181## O 54 H H ##STR182## H H 0 ##STR183## ##STR184## O 131-133 55 H H ##STR185## H H 0 ##STR186## ##STR187## O 56 H H ##STR188## H H 0 ##STR189## ##STR190## O 57 H H ##STR191## H H 0 ##STR192## ##STR193## O 58 H H ##STR194## H H 0 ##STR195## ##STR196## O 59 H H ##STR197## H H 0 ##STR198## ##STR199## O 60 H H ##STR200## -- -- 1 ##STR201## ##STR202## O
BIOCHEMICAL TEST PROCEDURE
The effect of compounds on the release of acetylcholine (ACh) from rat cerebral cortex slices was tested essentially using a slice superfusion procedure described by Mulder et al, Brain Res., 70, 372, (1974), as modified according to Nickolson et al, Naunyn Schmied. Arch. Pharmacol., 319, 48 (1982).
Male Wistar rats (Charles River) weighing 175-200 grams were used. They were housed for at least seven days before the experiment in the animal facility under a 12--12 hour light/dark cycle (light on 6.00 h, light off 18.00 h). They had ad lib access to standard rat chow (Purina) and deionized water.
Rats were decapitated and brains were dissected immediately. Slices (0.3 mm thick) from the parietal cortex were prepared manually using a recessed Lucite® guide and subsequently cut into 0.25×0.25 mm squares.
Slices (approximately 100 mg wet weight) were incubated in 10 ml Krebs-Ringer (KR) medium containing (mM): NaCl (116), KCl (3) CaCl 2 (1.3), MgCl 2 (1.2), KH 2 PO 4 (1.2), Na 2 SO 4 (1.2), NaHCO 3 (25), glucose (11), to which 10 μCi H-Choline (spec. act. approx. 35 Ci/mmol; NEN) and 10 nmoles unlabelled choline had been added to give a final concentration of 10 -6 M. Incubation was carried out for 30 minutes at 37° C. under a steady flow of 95% O 2 /5% CO 2 . Under these conditions, part of the radioactive choline taken up is converted into radioactive ACh by cholinergic nerve endings, stored in synaptic vesicles and released upon depolarization by high-K + -containing media.
After labelling of the ACh stores, the slices were washed 3 times with non-radioactive KR-medium and transferred to a superfusion apparatus to measure the drug effects on ACh release. The superfusion apparatus consisted of 10 thermostated glass columns of 5 mm diameter which were provided with GF/F glass fiber filters to support the slices (approximately 10 mg tissue/column). Superfusion was carried out with KR-medium (0.3 ml/min) containing 10 -5 M hemicholinium-3 (HC-3). HC-3 prevents the uptake of choline, formed during the superfusion from phospholipids and released ACh, which would be converted into unlabelled ACh, and released in preference to the pre-formed, labeled ACh. The medium was delivered by a 25-channel peristaltic pump (Ismatec; Brinkman) and was warmed to 37° C. in a thermostated stainless steel coil before entering the superfusion column. Each column was provided with a 4-way slider valve (Beckman Instruments) which allowed rapid change of low-to high-K + -KR -medium and with two 10-channel, 3-way valves which were used to change from drug-free to drug-containing low-and high-K + -KR-medium.
After 15 minutes washout of non-specifically bound radioactivity, the collection of 4 minute fractions was started. After 3 four-min. collections, the KR medium was changed for KR medium of which the KCl concentration had been increased to 25 mM (high-K + -KR-medium) (S1). Depolarization-induced stimulation of release by high-K + -KR-medium lasted for 4 minutes. Drug free low-and high-K + -KR-medium were then substituted by drug- or vehicle-containing low- and high-K + -KR-medium and superfusion was continued for 3 four-min. collections with low-K + -KR-medium, 1 four-min. collection with high-K + -KR-medium (S2) and 2 four-min. collections with low-K + -KR-medium.
Drug was added to the media by 100-fold dilution of appropriate concentrations of the drug (in 0.9% NaCl/H 2 O) with either low- or high-K + -KR-medium.
All superfusion fractions were collected in liquid scintillation counting vials. After superfusion the slices were removed from the superfusion columns and extracted in 1.0 ml of 0.1N HCl. To superfusion fractions and extracts 12 ml Liquiscint counting fluid (NEN) was then added and samples were counted in a Packard Tricarb Liquid Scintillation Counter. No corrections were made for quenching.
The ratio of S2/S1 (as compared to controls where no drug is present during S2) in a measure of the ability of the drug to enhance or depress stimulus-induced acetylcholine release. The in vitro ACh release data is summarized in Table 2.
TABLE 2______________________________________% INCREASE OF STIMULUS-INDUCED ACh RELEASEIN RAT CEREBRAL CORTEX IN VITROExample 10.sup.-6 10.sup.-5 10.sup.-4 (M)______________________________________1 -- -- +349*2 +11 +61* +265*3 +06 +88* +238*4 +94* +475* +433*5 +14 +78* +355*6 +195* +313* --7 -- 0 +30*8 -- +37* +429*9 0 +54* +275*12 -- +11 +48*13 0 +13 +100*16 +01 +47* --19 +34* +323* --43 +34* +210* --45 -- +12 +97*46 +20 +218* --49 +16* +49* --______________________________________ *Significantly different from control P < 0.05, student's ttest.
Using similar test procedure, the compounds of Examples 2 and 4 were also found to enhance the release of acetylcholine from hippocampal slices and that of acetylcholine and dopamine from caudate nucleus slices in vitro. The compound of Example 4, in addition, was found to also enhance the release of serotonin from cortical slices.
BEHAVIORAL TEST PROCEDURE
The effect of compounds on rat active avoidance (pole-climb) performance was studied as follows: Male Sprague-Dawley rats (Charles River), weighing 150-200 grams, received two blocks of five learning trials daily (1 AM, 1 PM), for four days. A trial consisted of placing a rat in a cage (Coulbourn Model E10--10, equipped with a removable shock gridfloor), facing a pole (wood, with parallel diagonal notches, mounted from the ceiling). The trial was started by closing the cage door and switching on the cage light. After 10 seconds, shock was applied through the gridfloor for 10 seconds by a Coulbourn Model E13-08 shocker. Footshock intensity ranged from 0.6 to 1.2 mA. At the end of the trial, the light and shock were turned off and the rat was removed from the cage. If the rat jumped on the pole prior to the onset of shock, it was considered to have avoided; if it jumped after the shock, it was considered to have escaped. Groups of 6 to 9 rats were subcutaneously treated with various doses of a compound or the corresponding vehicle 30 minutes prior to the first training trial of each block.
Active avoidance performance data were analyzed by regression analysis (see Snedecor and Cochran, Statistical Methods, 6th Edition, page 432) of the cumulative number of avoidances versus blocks of trials curve. The means slope and SEM (Standard Error of the Mean) of this curve were calculated for each treatment group and taken as a measure of active avoidance performance. Drug effects were expressed as percent change in slope compared to the slope of the control curve. The results are summarized in Table 3.
TABLE 3______________________________________% ENHANCEMENT OF ACTIVE AVOIDANCEPERFORMANCE IN RATSDrug Dose (mg/kg s.c.)Example 0.1 0.3 1 3 5 10 20______________________________________2 -- -- -- -- 54* 53* 214 +59* +91* +84* +57 -- -- --______________________________________ *Significantly different from control, P < 0.5, student's ttest.
UTILITY
The foregoing test results suggest that compounds of this invention have utility in the treatment of cognitive deficiencies and/or neurological function deficits and/or mood and mental disturbances, in patients suffering from nervous system disorders like Alzheimer's disease, Parkinson's disease, senile-dementia, multi-infarct dementia, Huntington's disease, mental retardation. Myasthenia Gravis etc. Compounds of this invention can be administered to treat said deficiencies by any means that produces contact of the active agent with the agent's site of action in the body of a mammal. The compounds can be administered by any conventional means available for use in conjuction with pharmaceuticals, either as individual therapeutic agents or in a combination of therapeutic agents. They can be administered alone, but are generally administered with a pharmaceutical carrier selected on the basis of the chosen route of administration and standard pharmaceutical practice.
The dosage administered will, of course, vary depending on the use and known factors such as the pharmacodynamic characteristics of the particular agent, and its mode and route of administration; age, health, and weight of the recipient; nature and extent of symptoms, kind of concurrent treatment, frequency of treatment, and the effect desired. For use in the treatment of said diseases, a daily oral dosage of active ingredient can be about 0.001 to 100 mg/kg of body weight. Ordinarily a dose of 0.01 to 10 mg/kg per day in divided doses one to four times a day or in sustained release form is effective to obtain the desired results.
Dosage forms (compositions) suitable for administration contain from about 1 milligram to about 100 milligrams of active ingredient per unit. In these pharmaceutical compositions the active ingredient will ordinarily be present in an amount of about 0.5-95% by weight based on the total weight of the composition.
The active ingredient can be administered orally in solid dosage forms, such as capsules, tablets, and powders, or in liquid dosage forms, such as elixirs, syrups, and suspensions. It can also be administered parenterally, in sterile liquid dosage forms.
Gelatin capsules contain the active ingredient and powdered carriers, such as lactose, starch, cellulose derivatives, magnesium stearate, stearic acid, and the like. Similar diluents can be used to make compressed tablets. Both tablets and capsules can be manufactured as sustained release products to provide for continuous release of medication over a period of hours. Compressed tablets can be sugar coated or film coated to mask any unpleasant taste and protect the tablet from the atmosphere, or enteric coated for selective disintegration in the gastrointestinal tract.
Liquid dosage forms for oral administration can contain coloring and flavoring to increase patient acceptance.
In general, water a suitable oil, saline, aqueous dextrose (glucose), and related sugar solutions and glycols such as propylene glycol or polyethylene glycols are suitable carriers for parenteral solutions. Solutions for parenteral administration preferably contain a water soluble salt of the active ingredient, suitable stabilizing agents, and if necessary, buffer substances. Antioxidizing agents such as sodium bisulfite, sodium sulfite, or ascorbic acid, either alone or combined, are suitable stabilizing agents. Also used are citric acid and its salts and sodium EDTA. In addition, parenteral solutions can contain preservatives, such as benzalkonium chloride, methyl-or propyl-paraben, and chlorobutanol.
Suitable pharmaceutical carriers are described in Remington's Pharmaceutical Sciences, A. Osol, a standard reference text in this field.
Useful pharmaceutical dosage-forms for administration of the compounds of this invention can be illustrated as follows:
CAPSULES
A large number of unit capsules are prepared by filling standard two-piece hard gelatin capsules each with 100 milligrams of powdered active ingredient, 150 milligrams of lactose, 50 milligrams of cellulose, and 6 milligrams magnesium stearate.
SOFT GELATIN CAPSULES
A mixture of active ingredient in a digestable oil such as soybean oil, cottonseed oil or olive oil is prepared and injected by means of a positive displacement pump into gelatin to form soft gelatin capsules containing 100 milligrams of the active ingredient. The capsules are washed and dried.
TABLETS
A large number of tablets are prepared by conventional procedures so that the dosage unit is 100 milligrams of active ingredient, 0.2 milligrams of colloidal silicon dioxide, 5 milligrams of magnesium stearate, 275 milligrams of microcrystalline cellulose, 11 milligrams of starch and 98.8 milligrams of lactose. Appropriate coatings may be applied to increase palatability or delay absorption.
INJECTABLE
A parenteral composition suitable for administration by injection is prepared by stirring 1.5% by weight of active ingredient in 10% by volume propylene glycol. The solution is made to volume with water for injection and sterilized.
SUSPENSION
An aqueous suspension is prepared for oral administration so that each 5 milliliters contain 100 milligrams of finely divided active ingredient, 100 milligrams of sodium carboxymethyl cellulose, 5 milligrams of sodium benzoate, 1.0 grams of sorbitol solution, U.S.P., and 0.025 milliliters of vanillin.
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Cognitive deficiencies and/or neurological function deficits and/or mood and/or mental disturbances are treated by the administration of 3,3-disubstituted indolines. The indolines have the formula: ##STR1## wherein: p is 0 or 1;
Z is O or S;
R is C 1 -C 10 alkyl, C 3 -C 8 cycloalkyl, 2-pyridyl, 3-pyridyl, 4-pyridyl or ##STR2## V, W, X, and Y independently are H, halo, C 1 -C 3 alkyl, OR 1 , NO 2 , CF 3 , CN or NR 1 R 2 ;
R 1 and R 2 independently are H or C 1 -C 3 alkyl; ##STR3## independently are 6-membered heterocyclic aromatic rings containing at least one nitrogen atom as a part of the ring optionally substituted with one substituent selected from the group C 1 -C 3 alkyl, halo, OR 1 or NR 1 R 2 ; or
an N-oxide or pharmaceutically suitable acid addition salt thereof.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a composition obtained from plant extracts, and more particularly to the composition comprising a specific ratio of green tea extract to turmeric extract. The present invention also relates to an application of the composition, and more particularly for promoting weight loss and reducing body fat. The present invention also relates to a pharmaceutical composition, and more particularly to the pharmaceutical composition comprising the above-said composition. The present invention also relates to an application of the pharmaceutical composition, and more particularly for promoting weight loss and reducing body fat.
[0003] 2. Description of the Prior Arts
[0004] As defined by the World Health Organization (WHO), the body mass index (BMI) greater than 25 is classified as overweight and BMI greater than 30 as obesity. According to the global statistics in 2014, the population of overweight and obesity is over 2.7 billion, of which approximately 13% population would be obese. These obese people suffer from cardiovascular diseases, hyperlipidemia, diabetes, and cancers at sharply higher probabilities than the average. According to the report of the WHO, among the global leading risks for mortality caused by diseases, overweight and obesity ranked 6th, and at least more than 3.4 million adults die of chronic diseases caused by overweight or obesity in 2013, wherein the medical burden of 44% of diabetes and 23% of ischemic heart disease are attributable to obesity. Studies also showed that the age of obese people is in a gradually downward trend. Approximately 40 million children under age five are overweight worldwide in 2011. According to the report by the Johns Hopkins University Bloomberg School of Public Health published in 2007, approximately 75% and 41% adults would be overweight and obese, respectively, in the USA in 2015. With the rising of developing countries, the population of obesity is rapidly increasing and obesity becomes one of the major epidemics. The Centers for Disease Control and Prevention (CDC) in the USA noted that the population of obese adults in the USA is more than 72 million, and 40% of global obese population is in Asia. The population of overweight and obese adults was increased from 25% to 38.5% in China from 2002 to 2010. Moreover, in 2015, the overweight population will be 50% to 57% in China.
[0005] Obesity is a health problem around the world, and the causes of obesity are complex with multiple factors involved. More and more evidences show that obesity is not only a simple self-control problem, but also involves appetite regulation and energy metabolism. Obesity not only increases mortality and causes huge medical burden to mankind, but also affects life quality. Though the cause of obesity is not completely established, it is believed to be related to genetics, metabolism, biochemistry, culture and psychological factors. Accordingly, many causes of death are considered to be correlated with obesity including cancers, cardiovascular diseases, diabetes, chronic lower respiratory diseases, chronic hepatic disease and liver cirrhosis, hypertensive diseases, renal disease, etc., all of which make obesity a global issue. Recently, the prevalence of obesity is rising accompanied by the metabolic abnormality in blood pressure, blood sugar, insulin resistance, and dyslipidemia, which gradually leads to the incidence of diabetes, cardiovascular diseases, atherosclerosis, cerebrovascular disease, stroke, myocardial infarction, and eventually death.
[0006] The mechanisms of current drugs for losing weight can be divided into two categories, one is appetite suppression, and the other is blocking the intestinal absorption of dietary fat; wherein the main mechanism of marketed weight loss drugs is appetite suppression, the drugs comprising Sibutramine (Reductil®), Lorcaserin (Belviq®), Qsymia®, Contrave, etc, which have severe side effects and high risk of cardiovascular diseases. Take off-shelve weight loss drug Sibutramine (Reductil®) for example, once having a market share as high as 70 percent, Sibutramine (Reductil®) is to dually increase the satiety effect through the central nervous system and the metabolic rate in the periphery to achieve the weight loss effect. Sibutramine (Reductil®) is a noradrenaline and serotonin reuptake inhibitor which increases satiety to suppress appetite and therefore achieves the purpose of weight loss, wherein satiety increase is through the inhibiting of serotonin and noradrenaline reuptake via α1-adrenoceptors, β1-adrenoceptors and 5-HT2 receptor subtypes. Sibutramine (Reductil®) may cause high blood pressure and increase heart rate and was proved to increase cardiovascular risks in recent years, therefore, the drugs containing Sibutramine (Reductil®) ingredients were recalled from the markets of Europe, the United States, Australia, Taiwan and other countries in 2010.
[0007] Orlistat (Xenical®) blocks the intestinal dietary fat absorption and is the only legitimate weight loss drug for long-term use in most countries. It is a specific, reversible gastrointestinal lipolysis enzyme inhibitor in the stomach and small intestine. Orlistat (Xenical®) and lipase secreted from stomach and pancreas will form a covalent bond in the serine of the activation site of lipase to inactivate lipase activity as to inhibit the hydrolysis of triglyceride in dietary fat to absorbable free fatty acids and monoglycerides. Undigested triglycerides are unabsorbable and will be excreted directly. By means of inhibiting digestion enzymes secreted from pancreatic and intestine, the intestinal absorption of fat could be reduced up to 25% to 30%. Moreover, as the mechanism of Orlistat (Xenical®) is blocking fat absorption, some significant side effects were found including oil stool, increasing bowel movement, bloating related to gastrointestinal tract, interfering fat-soluble vitamin absorption, liver damage, gallstones, etc.
[0008] Massive demand and high profits of weight loss drugs have drawn pharmaceutical companies to researches and investment thereon. However, the safety of weight loss drugs is a challenging issue, especially severe side effects and the risk of cardiovascular disease. Therefore, the FDA had stopped approving weight loss drugs for years before 2012, causing inactivity of the pharmaceutical market. In 2012, FDA finally approved another four weight loss drugs, respectively Lorcaserin (Belviq®), Qsymia®, Contrave and Saxenda®, expected to bloom the market of weight loss drugs again.
[0009] The main ingredients of Qsymia® and Lorcaserin (Belviq®) are respectively phentermine-topiramate and lorcaserin, the main mechanism of them is increasing satiety and suppressing appetite to achieve weight loss purposes. Phentermine and topiramate are both old components of drug ingredients, wherein phentermine is a central sympathomimetics, and the mechanism of phentermine is suppressing appetite by stimulating adrenal gland to secret norepinephrine through hypothalamus; wherein the mechanism of topiramate is to promote the activity of the neurotransmitter GABA, blocking sodium channels, antagonizing glutamine receptor and inhibiting carbonic anhydrase to inhibit appetite and increase satiety. However, as early as in 1997, 24 cases of valvular heart disease were reported after taking weight loss drugs containing phentermine Fen-Phen (fenfluramine/dexfenfluramine-phentermine) drove FDA to recall fenfluramine and dexfenfluramine from the market. Phentermine is contraindicated for patients at high cardiovascular risk in many countries. Topiramate has been approved to treat epilepsy. The side effects of Phentermine-topiramate drug include tingling hands and feet, dizziness, dysgeusia, insomnia, constipation, and dry mouth. Lorcaserin (Belviq®) is a 5-HT2C receptor activator, by activating hypothalamic pro-opiomelanocortin neurons (POMC neurons) to produce melanocyte stimulating hormone (α-MSH), and followed by inducing satiety, suppressing appetite and reducing dietary energy intake. Lorcaserin (Belviq®) is highly specific to 5-HT2C receptors instead of 5-HT2A and 5-HT2B receptors hence reduced the risk of severe cardiovascular diseases. As the side effects of Lorcaserin (Belviq®) include valve damage, headache, nausea, fatigue and urinary tract infections, FDA still requires the industry to conduct follow-up clinical monitoring, medication should be ceased if no significant weight loss after three months of Lorcaserin (Belviq®) treatment.
[0010] Contrave® is a dopamine and norepinephrine reuptake inhibitor, acting on the central nervous system to suppress appetite. The side effects of Contrave® are suicidal tendency, nausea, constipation, headache, vomiting, and dizziness. Saxenda® is a weight-loss drug administered by subcutaneous injection, and the main mechanism of Saxenda is mainly by reducing the rate of gastric emptying and increasing satiety to achieve the purpose of weight loss; the side effects are nausea, hypoglycemia, diarrhea, constipation, vomiting, headache, loss of appetite and etc. Overall, the risk of cardiovascular disease and the safety of long-term use of new weight loss drugs remained to be monitored for longer period. Because of numerous side effects and safety concerns, these new weight loss drugs are not suitable for patients with cardiovascular diseases, especially Qsymia® which contains phentermine and reported to cause severe cardiovascular diseases made Qsymia® still forbidden in Taiwan and many other countries.
[0011] The main concern of weight loss drugs is the cardiovascular risk or mental safety such as dizziness, insomnia, palpitations, constipation and other side effects for long-term use. As the currently approved weight loss drugs have severe side effects, poor tolerance, and cardiovascular risk, the pharmaceutical market of weight loss drugs has not grown in pace with the global obese population and demand. Five among ten approved anti-obesity drugs from 1957 to 2014 which act through the mechanism involving appetite inhibition were recalled by FDA for their CVD risks or psychiatric safety concern included Sibutramine (trade name Reductil®) which launched in 2002 and shared 70% market revenue.
[0012] To overcome the described side effects and safety concern found in the launched weight loss products, better drugs developed based on weight loss function and reduction of CVD risk factors are urgently required.
SUMMARY OF THE INVENTION
[0013] To overcome the shortcomings of side effects and cardiovascular risks of currently weight loss drugs. The objective of the present invention is to provide a plant extract composition for promoting weight loss and reducing body fat. The composition comprises a green tea extract and a turmeric extract, and the percentages of green tea extract and turmeric extract are respectively 30 wt % to 75 wt % and 20 wt % to 55 wt % of a total weight of the composition. Preferably, the plant extract composition further comprises resveratrol, wherein a percentage of the resveratrol is between 0 wt % and 30 wt % of the total weight of the composition. It is notable that treatment of resveratrol or turmeric extract alone in animal experiments has no significant effects on reducing body weight and body fat which was consistent with the previous findings. More importantly, the plant extract composition of the present invention administered simultaneously with high fat diet significantly reduced body weight and body fat in animal model. Furthermore, the plant extract composition of the present invention also significantly reduced body weight and body fat in diet-induced obese mice model. Compared to that of the commercially available weight loss drug Orlistat (Xenical®), the reduction effect of body weight and body fat of the plant extract composition of the present invention is significantly better (p <0.001). The better effect of the present invention was proved in the diet-induced obesity model which is more difficult than the model simultaneous administered with compositions and obesity induction to reduce body weight and body fat and is much closer to the clinical treating of overweight and obesity patients. Under the circumstances of animal model with obesity, the effects of the present invention on reduction of body weight and body fat are better than those of commercial drug or single plant extract explained the nonobviousness and novelty of the composition of the present invention.
[0014] According to the present invention, the term “turmeric extract” as used herein mainly comprises curcumins. Preferably, the amount of the curcumins in the turmeric extract is from 80% to 100%. The term “green tea extract” as used herein mainly comprises catechins, and the amount of the catechins of the total amount of the green tea extract is from 75% to 100%.
[0015] In one preferred embodiment, the present invention further provides a method for preparing the plant extract composition containing a green tea extract and a turmeric extract comprising the following steps: mixing the plant extract composition containing a green tea extract and a turmeric extract with a pharmaceutically acceptable salt, a pharmaceutically acceptable stabilizer or a pharmaceutically acceptable excipient to form capsules, tablets, film-coated tablets or injection fluids.
[0016] Preferably, the method further comprises resveratrol to form a composition containing a green tea extract, a turmeric extract and resveratrol.
[0017] Preferably, the stabilizers include, but are not limited to, xylitol, sorbitol, polydextrose, isomalt, and dextrose.
[0018] The present invention also provides a pharmaceutical composition for reducing body weight and body fat, containing the plant extract composition and the pharmaceutically acceptable excipient.
[0019] Preferably, the pharmaceutical composition further comprises an effective amount of resveratrol for reducing body weight and body fat.
[0020] According to the present invention, the term “a pharmaceutically acceptable excipient” as used herein includes, but is not limited to, disintegrant, binder, filler, lubricant, suspending agent, solubilizer, and glidant. The amount of excipient employed will depend upon quantity of the active agent. One excipient can perform more than one function.
[0021] Preferably, examples of disintegrant include, but are not limited to, agar, alginic acid, calcium carbonate, carboxymethylcellulose, cellulose, clays, colloidal silica, croscarmellose sodium, cross-linked povidone, gum, magnesium aluminum silicate, methyl cellulose, polacrilin potassium, sodium alginate, low substituted hydroxypropyl cellulose, crosslinked polyvinylpyrrolidone hydroxypropylcellulose, sodium starch glycolate, or starch.
[0022] Preferably, examples of binder include, but are not limited to, microcrystalline cellulose, hydroxymethyl cellulose, hydroxypropyl cellulose, or polyvinyl pyrrolidone.
[0023] Preferably, examples of filler include, but are not limited to, calcium carbonate, calcium phosphate, dibasic calcium phosphate, tribasic calcium sulfate, calcium carboxymethylcellulose, cellulose, dextrin, salt, dextrin, dextrose, fructose, lactitol, lactose, carbonate, magnesium oxide, maltitol, maltodextrin, maltose, sorbitol, starch, sucrose, sugar, or xylitol.
[0024] Preferably, examples of lubricant include, but are not limited to, agar, calcium stearate, ethyl oleate, ethyl laureate, glycerin, glyceryl palmitostearate, hydrogenated vegetable oil, magnesium oxide, magnesium stearate, mannitol, poloxamer, ethylene glycol, sodium benzoate, sodium lauryl sulfate, sodium stearoyl acid, sorbitol, stearic acid, talc or zinc stearate.
[0025] Preferably, examples of suspending agent include, but are not limited to, mannitol, carboxymethyl cellulose (CMC), or CMC-Na.
[0026] Preferably, examples of solubilizer include, but are not limited to, hydroxypropyl-beta-cyclodextrin, tween 80, castor oil or polyethylene glycol (PEG).
[0027] Preferably, examples of glidant include, but are not limited to, magnesium stearate, silicon dioxide, magnesium trisilicate, powdered cellulose, starch, talc, tribasic calcium phosphate, calcium silicate, magnesium silicate, colloidal silica or silicon hydrogel.
[0028] In accordance with the present invention, the pharmaceutical composition for reducing body weight and body fat is prepared for multiple forms, including, but not limited to, liquid, semi-solid and solid dosage, such as liquid solution (including injectable and infusible solution), dispersions, suspensions, tablets, pillars, powders, liposomes or suppositories. Preferred form depends on the mode of administration and therapeutic application of expectations. Preferably, the pharmaceutical composition of the present invention is administered orally or in the form of infusion solutions. In an embodiment of the present invention, the pharmaceutical composition at the effective amount is orally administered. According to the present invention, the formulation is preferred for pill, granules, film-coated tablets, capsules, tablets and other solid formulations are also contemplated within the scope of the present invention.
[0029] The present invention further provides a method for reducing body weight and body fat comprising a step of administering to a subject in need thereof a therapeutically effective amount of the pharmaceutical composition comprising a green tea extract and a turmeric extract; wherein the subject is an animal or a human.
[0030] Preferably, the formulation of the pharmaceutical composition is orally administered or administered by injection.
[0031] Preferably, the therapeutically effective amount of the pharmaceutical composition for a human is from 1.8 mg/kg body weight (B.W.) to 145 mg/kg B.W. More preferably, the therapeutically effective amount of the pharmaceutical composition for a human is from 5.4 mg/kg B.W. to 70 mg/kg B.W.
[0032] According to the present invention, the term “effective dose” could be calculated according to different subjects from the announcement of Table 1 of “estimating the maximum safe starting dose in initial clinical trials for therapeutics in adult healthy volunteers” from the Food and Drug Administration (FDA).
[0033] According to the present invention, the term “reducing body weight and body fat” as used herein refers to the body weight and body fat both less than the control group after administration of an effective amount of the composition comprising a green tea extract and a turmeric extract. As shown in the embodiment of the present invention, reducing body fat can be determined by administering the composition comprising a green tea extract and a turmeric extract or further comprising resveratrol in a specific dosage, and measuring the difference of epididymis fat, perinephric fat, mesenteric fat, groin fat and fat outside of peritoneal cavity in a specific period.
[0034] The components of the plant extract composition of the present invention are all extracted from plants, and the results in accordance with the present invention show that the composition of the present invention neither affects appetite or food intake, nor affects serum biochemical indicators. Therefore, the composition of the present invention is safer and less side effects compared to those of commercially available weight loss drugs. Furthermore, compared to conventional weight loss drugs, the plant extract composition not only reduces body weight, but also inhibits adipocytes growth, increases the metabolism of body fat and energy expenditure. In other words, the plant extract composition of the present invention can improve obesity fundamentally, so as to reduce the regain of body weight, improve the cardiovascular indicator including blood lipids and blood sugar as to reduce cardiovascular risks.
[0035] Therefore, the plant extract composition of the present invention provides a safer solution for modern global obesity and overweight issues, and can effectively reduce body weight and body fat for application of pharmaceutical composition or health food.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] FIG. 1 illustrates the bar chart in each group for inhibiting preadipocytes growth through MTT assay;
[0037] FIG. 2 illustrates the bar chart in each group for inhibiting differentiating adipocytes growth through MTT assay;
[0038] FIG. 3A illustrates the bar chart of body weight gain of mice administered with obesity induction and indicated composition simultaneously.
[0039] FIG. 3B illustrates the bar chart of fat mass of visceral fat, subcutaneous fat, and total fat mass of mice administered with obesity induction and indicated composition simultaneously.
[0040] FIG. 4A illustrates the bar chart of body weight gain of diet-induced obese mice administered with indicated compositions.
[0041] FIG. 4B illustrates the bar chart of fat mass of visceral fat, subcutaneous fat, and total fat mass of diet-induced obese mice administered with indicated compositions.
[0042] FIG. 5A illustrates the difference of body weight gain of rat administered with obesity induction and indicated composition simultaneously.
[0043] FIG. 5B illustrates the bar chart of fat mass of visceral fat of rat administered with high fat diet and indicated composition simultaneously.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0044] Other objectives, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.
Example 1
Preadipocytes Inhibition Assay
[0045] 3T3-L1 preadipocytes (purchased from FIRDI, Taiwan) were seeded at a density of 1×10 4 cells/well in 96-well plates. Three repeated cell experiments were examined using 1% DMSO as control group, and 50 ppm resveratrol, 50 ppm turmeric extract, 80 ppm green tea extract and 100 ppm of the formulations ME008A, ME008D, ME001, ME00C1, and ME00D1 respectively for nine groups. After incubation for 48 hours, the inhibitory effect on 3T3-L1 preadipocytes was analyzed by MTT assay. The formulation ME008A in accordance with the present invention has 50 wt % green tea extract, 25 wt % green coffee bean extract, and 25 wt % resveratrol. The formulation ME008D in accordance with the present invention has 40 wt % green tea extract, 45 wt % green coffee bean extract, and 15 wt % resveratrol. The formulation ME001 in accordance with the present invention has 60 wt % green tea extract, 10 wt % turmeric extract, and 30 wt % resveratrol. The formulation ME00C1 in accordance with the present invention has 40 wt % green tea extract, 50 wt % turmeric extract, and 10 wt % resveratrol. The formulation ME00D1 in accordance with the present invention has 75 wt % green tea extract and 25 wt % turmeric extract. All data are presented as Mean ±SD. The letters a, b, c, d, e, f, and g represent the results of the statistics, and the different letters represent statistical difference among the groups (p<0.05).
[0046] As shown in FIG. 1 , compared to the control group, the formulations ME00C1, ME001, and ME008D of the present invention all could inhibit preadipocytes growth (p<0.05); wherein the formulation ME00C1 had the best inhibitory effect on preadipocytes (p<0.05). The inhibitory effect of the formulation ME00C1 was greater than that of the resveratrol, the turmeric extract, or the green tea extract (p<0.05).
Example 2
Differentiating Adipocytes Inhibition Assay
[0047] 3T3-L1 cells were seeded at a density of 1×10 5 cells/well in 12-well plates. After seeding for about four day, medium was changed and replaced with 5 μg/ml insulin (differentiation agent), 1 μM dexamethasone, 0.5 mM 3-isobutyl-1-methylxanthine. Three repeated cell experiments were examined using 1% DMSO as control group, and 50 ppm resveratrol extract, 50 ppm turmeric extract, 80 ppm green tea extract, 100 ppm formulations ME008A, ME008D, ME001, ME00C1, and ME00D1 respectively for nine groups. After incubation for another 48 hours, the inhibitory effect on differentiating adipocytes 3T3-L1 was analyzed by MTT assay. All data are presented as Mean ±SD. The letters a, b, c, d, e, and f represent the results of the statistics, and the different letters represent statistical difference among the groups (p<0.05).
[0048] As shown in FIG. 2 , compared to the control group, the formulations of the present invention all could inhibit differentiating adipocytes growth significantly, wherein formulation ME00C1 had the best inhibitory effect on differentiating adipocytes. The inhibitory effect of the formulation ME00C1 was greater than that of the resveratrol, the turmeric extract, or the green tea extract (p<0.05).
Example 3
Animal Assay (I) (Obesity Induction and Administration Simultaneously)
[0049] C57/BL6 female mice aged 8 weeks were used in this example. There were five groups for test, respectively as a control group, an obese group, a resveratrol group (formulation: 61.5 mg/kg B.W.), a green tea extract group (formulation: 123 mg/kg B.W.), and an experimental group (the formulation of ME001 of the present invention: 676.5 mg/kg B.W.). Five female mice were used in each group. In duration, high fat diets were fed for all groups to induce obesity except for the control group, and resveratrol, green tea extract and the formulation of ME001 were administered respectively and simultaneously for 8 weeks, the obese group was tube-fed with sterile water to evaluate the difference of bodyweight gain and body fat of each group; meanwhile, body weight and average food intake were recorded weekly. The mice were sacrificed, the fat around the ovary, perinephric fat, and mesenteric fat were weighed and calculated to obtain visceral fat mass, and the fat around the groin and peritoneal cavity was calculated to obtain subcutaneous fat mass. All data are presented as Mean ±SD. The letters a, b, c, d, e, and f represent the results of the statistics, the different letters represent statistical difference among the groups (p<0.05), and the identical letter represents no statistical difference among the groups (p>0.05).
[0050] As shown in FIGS. 3A and 3B , the body weight gain of the formulation ME001 was significantly lower than that of obese group by 47.2% (p <0.05). Therefore, the formulation ME001 of the present invention can reduce the body weight effectively (p <0.05). In contrast, the body weight gain, the amount of visceral fat, subcutaneous fat, and body fat of the resveratrol group showed no statistical difference compared to the obese group (p>0.05).
[0051] Compared to the obese group, the formulation ME001 of the present invention could reduce the amount of visceral fat, subcutaneous fat, and body fat significantly (p <0.05). Besides, compared to those of other groups, the formulation ME001 of the present invention can also reduce body weight and body fat, and the effect was better than those of single plant extract groups such as the resveratrol group and the green tea extract group (p <0.05). In experimental periods, no statistical difference was found in the daily food intake in mice fed with a high-fat diet (p>0.05).
Example 4
Animal Assay (II) (Obesity Induction First and Then Administration)
[0052] C57/BL6 female mice aged 8 weeks were used in this example. All groups were fed with high fat diets except the control group for six weeks to obtain diet-induced obese mice (the weight gain was over 20%). The obese mice were divided into seven groups for test, respectively as an obese group, an Orlistat (Xenical®) group (formulation: 34.8 mg/kg B.W.), a turmeric extract group (formulation: 41 mg/kg B.W.), and four experimental groups such as the formulation ME008A (formulation: 676.5 mg/kg B.W.), the formulation ME008D (formulation: 676.5 mg/kg B.W.), the formulation ME001 (formulation: 676.5 mg/kg B.W.), and the formulation ME00C1 (formulation: 651.9 mg/kg B.W.). Five female mice were used in each group. High fat diets were fed for all groups to induce obesity except for the control group, and Orlistat (Xenical®), turmeric extract and the formulations of ME008A, ME008D, ME001, and ME00C1 were administered respectively, the obese group was tube-fed with equal volume sterile water for eight weeks, to evaluate the difference of body weight gain and body fat of each group; meanwhile, the body weight and the average food intake were recorded weekly. The mice were sacrificed, the fat around the ovary, perinephric fat, and mesenteric fat were weighed and calculated to obtain visceral fat mass, and the fat around the groin and peritoneal cavity was calculated to obtain subcutaneous fat mass. All data are presented as Mean ±SD. The letters a, b, c, d, and e represent the results of the statistics, the different letters represent statistical difference among the groups (p<0.05), and the identical letter represents no statistical difference among the groups (p>0.05).
[0053] As shown in FIGS. 4A and 4B , the body weight gain of the obese group was significantly higher than that of the control group by 87.7% (p <0.05) representing that obesity was induced successfully. The formulations of ME008D, ME001, and ME00C1 of the present invention can reduce the gain of body weight significantly (p <0.05), wherein the formulation ME00C1 had the best reduction effect on the gain of body weight, specifically, better than that of the Orlistat (Xenical®) group (p <0.05) and the turmeric extract group (p <0.05).
[0054] The body fat mass(comprising visceral fat and subcutaneous fat) of the groups of formulations ME008D, ME001, and ME00C1 of the present invention were reduced significantly (p <0.05), wherein the body fat was decreased by 10.3%, 36.9%, and 64.1% respectively. The formulation ME00C1 had the best reduction effect on the gain of body fat, better than those of the Orlistat (Xenical®) group (p <0.05) and the turmeric extract group (p <0.05). Therefore, the formulation ME00C1 of the present invention can reduce body weight and body fat more effectively than other groups. In experimental duration, mice in each group fed with a high-fat diet showed no statistical difference (p>0.05).
Example 5
Animal Assay (III) (Obesity Induction and Administration Simultaneously)
[0055] Sprague-Dawley (SD) male rats aged 8 weeks were used in this example. There were four groups for test, respectively as a control group, an obese group, two experimental groups with formulation ME00C1 (formulation: 199.6 mg/kg BW) and formulation ME00C1A (formulation: 186 mg/kg BW), wherein the formulation ME00C1A in accordance with the present invention has 55.5 wt % green tea extract and 44.5 wt % turmeric extract. Six rats were used in each group. High fat diets were fed for all groups to induce obesity except for the control group, and the formulations of ME00C1 and ME00C1A were administered respectively and simultaneously, the obese group was tube-fed with equal volume sterile water for eight weeks to evaluate the difference of body weight gain and body fat of each group; meanwhile, the body weight and the average food intake were recorded weekly. The rats were sacrificed, and epididymal fat, perinephric fat, and mesenteric fat were weighed and calculated to obtain visceral fat mass. All data are presented as Mean ±SD. The letters a, b, c, and d represent the results of the statistics, the different letters represent statistical difference among the groups (p<0.05), and the identical letter represents no statistical difference among the groups (p>0.05).
[0056] As shown in FIG. 5A , the gains of body weight of the groups of the formulations ME00C1 and ME00C1A of the present invention were decreased significantly compared to that of obese group. The gain of body weight of the formulation ME00C1 was decreased by 23.0% (p<0.01 valued by t-test), and the gain of body weight of the formulation ME00C1A was decreased by 29.8% (p<0.01 valued by t-test). As shown in FIG. 5B , the visceral fat (comprising epididymal fat, perinephric fat, and mesenteric fat) of the formulation ME00C1A of the present invention was reduced significantly (p <0.05), wherein the visceral fat was decreased by 35.7%, representing that the formulation ME00C1A had the best reduction effect on the gain of body weight and body fat.
[0057] Even though numerous characteristics and advantages of the present invention are revealed and described as above, together with details of the structure and features of the invention, the disclosure is illustrative only. Changes may be made in the details, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
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Provided is a plant extract composition and a pharmaceutical composition thereof for reducing body weight and body fat, wherein the plant extract composition comprises a green tea extract and a turmeric extract respectively 30 wt % to 75 wt % and 20 wt % to 55 wt % of a total weight of the composition. In diet-induced obesity models, either obesity is induced first or simultaneously with administration, the plant extract composition and a pharmaceutical composition thereof can reduce body weight and body fat more significantly than a single plant extract or commercially available weight loss drugs.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of The Invention
[0002] Applicant's invention relates to a purified natural zeolite pigment composition for filling and/or coating paper. More particularly, the present invention relates to a purified natural zeolite pigment composition that can be used for coating paper that produces a paper that exhibits improved characteristics over existing uncoated and coated papers made with other pigments.
[0003] 2. Background Information
[0004] Pigments are used in papermaking and paper coating to improve the appearance, optical properties and printability of papers. Commonly used pigments include kaolin clay, calcium carbonate, titanium dioxide, alumina trihydrate and polystyrene. These pigments are useful in manufacture of conventional printing and writing papers and paperboards that are printed or imaged by common processes including offset lithography, gravure and xerography. Recently developed imaging technology has created needs for new types of coated and uncoated papers with properties not achievable with conventional pigments. Ink jet printing is a useful example.
[0005] Ink jet printing technology has undergone several changes in addressing the demands of existing and future digital printing applications that require high quality printed images. High quality ink jet printing typically occurs on coated paper; therefore, to produce such high quality printed images the coating composition and the ink formulation must be considered.
[0006] Current ink jet papers rely on the novel properties of the coating material to create desired properties to dry and set the ink solutions. Jet inks typically contain 2.5% by weight of organic dyes. The dye is fixed to the paper surface either by evaporation of a base such as ammonia, by migration of a base such as diethanolamine into the paper, or by changes in ionic environment when the ink meets the coating material layer.
[0007] The paper must exhibit unique properties in order to produce a high quality printed image when the ink is fixed to the paper surface. Once the ink drop is accepted by the paper, the ink must adhere to the paper and spread minimally in all directions to generate sharp edges for print contrast 1 and image fidelity. The paper must be smooth to give high print densities 2 . In addition, the paper should minimize bleeding 3 and wicking while promoting the absorption of ink to set the dye onto the coated surface since this promotes higher print densities. Ink jet droplets must be adsorbed quickly to avoid image smearing and multiple drop splatter. The dyes should be deposited near the paper surface to maximize color density and contrast while minimizing show through 4 .
[0008] Coating, which generally contains pigment, binders, and additives, is applied to the paper surface to improve the properties of the paper. The ink interacts with the coating to produce a high quality image. The coating prevents the ink from penetrating into the substrate. More specifically, the coating can optimize drying time for high water content dyes and separate the water-soluble organic dyes from the water vehicle and hold the dye on the surface so it doesn't strike through to the base sheet. Smoothness and thickness of the coating layer are two important physical properties that impact print quality. Pore structure and contact angle wettability effect print quality by preventing ink spreading. In order to prevent wicking and feathering 5 , it is important that the thickness of the coating layer be homogenous to a scale of a few microns in depth which also helps in the absorption of successive droplets of ink at high delivery rates and any water present.
[0009] Paper made for ink jet printing should have a hydrophilic, high porosity surface with no macroscopic structure in order to absorb ink jet droplets quickly with little spreading, wicking or dye penetration. Therefore the preferred coating for the paper surface should contain a highly porous, high surface area pigment that wets almost instantly with water. If the coating has sufficient thickness and void volume, it should be able to absorb successive droplets in multicolor printing at the highest delivery rates of commercial ink jet printing. The dye should react with the coating material to make it waterfast and rub resistant. The coating should have near neutral or alkaline pH to avoid shifts from the intended color of the dyes.
[0010] The rate of ink penetration has a large effect on final optical density through its effect on drying time and setting of the dye on the coated surface. The rate of ink penetration can be explained by the Lucas Washburn Equation of capillary flow:
I 2 =γr (cos θ) t/ 4 v
[0011] where I is the depth of ink penetration, r is the pore radius, t is time, γ is the surface tension, θ is the contact angle, and v is the viscosity of the ink. In generating high print quality, the rate of ink penetration must be modified to allow sufficient wetting to occur. The hydrophilic/hydrophobic surface chemistry of the coating plays an important role in the development of image quality through the control of dot gain. Sufficient dot gain requires the dot spreading on a smooth surface and is a function of contact angle. The contact angle is itself a function of the interactions between the surface tension of the liquid, surface vapor, and liquid vapor interfaces. The determination of sufficient dot gain can be characterized through the surface tension of the interfaces from Young's equation:
γ slv =γ si +γ iv cos θ
[0012] This equation evaluates the development of the contact angle which controls spread of liquid through the surface tensions involved. If the contact angle is less than 90 degrees, surface roughness will reduce the contact angle even more. Whereas if the contact angle is greater than 90 degrees the surface roughness will increase the contact angle. Porosity also effects the measured contact angle.
[0013] The interactions between ink and the coated substrate play a vital role in producing images that are long lasting, well defined and of high strength regardless of printer application. The main interaction occurs at the surface of the substrate, where the type of bonding that occurs between the colorant and the media dictates the final print quality. The interactions that take place between the colorant and the plain paper are controlled by hydrogen bonding and Van der Waals forces, while ionic and electrostatic forces are responsible for the interactions between the colorant and the coated paper.
[0014] Hydrogen bonding is the most significant bonding that takes place between color and media, where cellulosic material is involved. For a large dye molecule, a large number of sites are available for hydrogen bonding which encourage the interaction between the colorant and the media. Hydrogen bonding between color and media increases the strength of the color binding on the media. Furthermore, the hydroxyl groups of the cellulose may interact with the δ cloud of an aromatic group on the colorant by hydrogen bonding.
[0015] Van der Waals forces are very weak when the interacting groups are far apart and a weak repulsion typically exists between the media and anionic dyes. The interaction between colorant and media becomes strong as the dyes start penetrating into the base sheet.
[0016] Electrostatic forces occur due to coloumbic attraction. The cationic groups on the media, such as Ti 3+ , Al 3+ , and Ca 2+ attract anionic dyes, such as water-soluble groups of SO 3 2− , COO − , and PO 4 3− . The result is strong attraction between these groups, which causes an effective immobilization of the dye molecules, resulting in excellent print quality.
[0017] The δ-δ interactions are very strong interactions that typically occur between dye molecules. These interactions normally generate either dye aggregation or crystallization 6 . If dye-dye interactions on the paper substrate are stronger than dye-paper interactions, dye may aggregate on the substrate causing printing problems. Thus a strong interaction between colorant and media is required.
[0018] Hydrogen bonding and Van der Waals forces are the main interactions that occur in plain papers. Plain papers mainly consist of cellulose and therefore the main interactions are between the color and the cellulose. The penetration of color into the substrate will be controlled by capillary adsorption. If the paper has been internally or surface sized the rate of penetration of the colorant will be decreased which may lead to some ink bleeding and feathering problems.
[0019] The interaction of the colorant with coated paper is different however. The selection of the coating and ink formulation will have a significant effect on the ink absorption rate, image quality, and water/light fastness properties of the liquid ink. Electrostatic or ionic interactions play the key role in colorant coated paper interactions. Electrostatic interaction is stronger than hydrogen bonding and Van der Waals interactions. These interactions are more efficient, as the colorant is fixed in the vicinity where it was printed. The nature of the anionic dyes and the oxides will determine the print quality of ink jet printing since electrostatic interactions of the colorant with coated media occur between the anionic groups of the dyes and oxides. The binding energies of the dyes are greatly increased by electrostatic interactions resulting in high bonding strength.
[0020] Existing coated ink jet papers are mainly dependent on amorphous and gelled silica, which possess high micro porosity and macro porosity. The porous coating structure provides the driving force for the rapid diffusion of ink liquid into the coating layer and internal pore volume of the coating for storing large amounts of ink. These two properties interact to set the anionic dye at or near the coating surface, generating higher optical printing densities. The high surface area of the silica requires a strong binder to maintain adhesion to the paper and cohesion within the coating structure. Therefore, polyvinyl alcohol, the strongest binder available, is used.
[0021] Unfortunately, the current use of silica and polyvinyl alcohol has several limitations that effect the coating. The internal porosity of the silica pigments and the degree of hydrolysis of the polyvinyl alcohol limits running the coating solids at 20%. Silica pigments pose production problems and high cost because they must be coated at relatively slow speeds. Coating solids level is a major limiting factor with silica pigments because of viscosity, water absorption, and drying issues. Silica slurries alone do not usually flow well at levels above 15 to 20% solids, so dispersants are used to increase their concentrations. Also, silica has a great affinity for water given its high pore volume so it forms a paste as water is added until all the voids are filled. Only then is it fluid enough for the coating formulation. This behavior decreases the vehicle available for the slurry, so formulators must start at a lower solids concentration. The absorbed water in the pores also demands extra energy during drying. Calcium carbonate is another material sparingly used for ink jet printer coatings that dry similar to silica, but its surface area and void volume are much lower than silica—resulting in inferior image quality. It is also abrasive and can exhibit poor coater runnability. Its use is limited to cast coated ink jet papers for glossy photo prints where it is used as a supplementary pigment to silica.
[0022] With the compositions for coating paper currently on the market higher quality coated ink jet papers must be coated off-machine and are not cost effective. Producing a paper sheet with the desired properties is difficult due to the need to find ways to coat ink jet paper on-machine at commercial speeds with no loss in quality. The preferred finished ink jet paper should be smooth, strong, opaque, bright, and able to handle the demands of ink jet printing while providing excellent print results, such as excellent ink adherence, high scratch and ink resistance, and bleed control for sharp edges. It was therefore necessary to develop the composition for coating paper of the present invention that produces a coated paper that overcomes the disadvantages of the existing art while presenting a high print quality image at a reduced cost. More specifically, the present invention contemplates substituting a zeolite pigment for silica in matte ink jet coating formulations.
[0023] A zeolite pigment that possesses the desirable combination of brightness, color, particle size distribution, surface area, internal void volume, rheology and hardness could also be useful in overcoming the limitations of conventional and other specialty pigments in various papermaking and paper coating applications including but not limited to: (1) toner bond improvement in laser and other dry toner imaged digital papers; (2) elimination of smudging and improvement of print quality in direct print flexography on coated linerboard used in corrugated containers; (3) elimination of print through on newsprint and ultra light weight coated papers; (4) improvement of dot fidelity and print quality on coated rotogravure printing papers; (5) low abrasion extender for titanium dioxide pigments; (6) improvement of coefficient of friction of paper and paperboard; (7) production of technical specialty papers such as anti-tarnish, gas filtration, and absorbent papers with improved properties and lower cost of manufacture; (8) more economical microparticulate retention system chemistry; (9) additive to improve the efficiency of deinking systems.
[0024] Zeolites are crystalline, hydrated aluminosilicates of the alkali and alkaline earth metals. More particularly, zeolites are framework silicates consisting of interlocking tetrahedrons of SiO 4 and AlO 4 . In order to constitute a zeolite the ratio of silicon and aluminum to oxygen must be ½. The alumino-silicates structure is negatively charged and attracts the positive cations that reside within. When exposed to higher charged ions of a new element, zeolites will exchange the lower charged element contained within the zeolite for a higher charged element. Unlike most other tectosilicates, zeolites have large vacant spaces or cages in their structures that allow space for large cations such as sodium, potassium, barium, and calcium and relatively large molecules and cationic molecules, such as water, ammonia, carbonate ions, and nitrate ions. In most useful zeolites, the spaces are interconnected and form long wide channels of varying sizes depending on the mineral. These channels allow ease of movement of the resident ions and molecules into and out of the structure.
[0025] Zeolites are characterized by 1) a high degree of hydration, 2) low density and large void volume when dehydrated, 3) stability of the crystal structure of many zeolites when dehydrated, 4) uniform molecular sized channels in the dehydrated crystals, 5) ability to absorb gases and vapors, 6) catalytic properties, and 7) cation exchange properties.
[0026] The use of natural zeolites in paper making has a long history, but has been almost unique to Japan where zeolite has been used as filler to improve bulkiness and printability. Natural zeolites have also been used as fillers for paper in Hungary. These natural zeolites however are a low brightness material and this renders it unsatisfactory for application in the United States on coated ink jet paper where high brightness is expected.
[0027] Numerous families of natural zeolites exist and each has varying characteristics. Unfortunately, natural zeolites exhibit nonuniform properties that makes them difficult to work with in many applications because ores from one location can vary with any other. It is however possible to manufacture zeolites with uniform properties. The preferred zeolite for use in the present invention is a processed form of the natural mineral clinoptilolite which is a hydrated sodium potassium calcium aluminum silicate having the formula (Na, K, Ca) 2-3 Al 3 (Al,Si) 2 Si 13 ) 36 —12H 2 O. This zeolite is within the family Heulandite that also includes the mineral heulandite which is a hydrated sodium calcium aluminum silicate. The physical characteristics of raw clinoptilolite are listed in Table 1.
TABLE 1 PHYSICAL CHARACTERISTICS OF CLINOPTILOLITE Color is colorless, white, pink, yellow, reddish and pale brown. Luster is vitreous to pearly on the most prominent pinacoid face and on cleavage surfaces. Transparency: Crystals are transparent to translucent. Crystal System is monoclinic; 2/m. Crystal Habits include blocky or tabular crystals with good monoclinic crystal form. More tabular and proportioned than heulandite. Also commonly found in acicular (needle thin) crystal sprays. Cleavage is perfect in one direction parallel to the prominent pinacoid face. Fracture is uneven. Hardness is 3.5-4, maybe softer on cleavage surfaces. Specific Gravity is approximately 2.2 Streak is white.
[0028] Clinoptilolite's structure is sheet like with a tectosilicate structure where every oxygen is connected to either a silicon or an aluminum ion (at a ratio of [Al+Si]/O=½). The sheets are connected to each other by a few bonds that are relatively widely separated from each other. The sheets contain open rings of alternating eight and ten sides. These rings stack together from sheet to sheet to form channels throughout the crystal structure. The size of these channels controls the size of the molecules or ions that can pass through them. Clinoptilolite is well suited for various applications, such as in paper coating compositions, because it exhibits large pore space, high resistance to extreme temperatures, and has a chemically neutral structure.
SUMMARY OF THE INVENTION
[0029] An object of the present invention is to provide a novel purified natural zeolite pigment for coated ink jet papers and digital printing papers to replace silica pigments.
[0030] Another object of the present invention is to provide a novel purified natural zeolite pigment that can be used as a specialty coating pigment in coated linerboard for direct post print flexography to prevent smudging and to improve image fidelity.
[0031] Still another object of the present invention is to provide a novel purified natural zeolite pigment that can act as a supplementary coating pigment in ultra lightweight coated publication papers.
[0032] It is yet another object of the present invention to provide a novel purified natural zeolite pigment that can act as a supplementary coating pigment for water based gravure 7 printing papers.
[0033] An additional object of the present invention is to provide a novel purified natural zeolite pigment that can replace calcined kaolin as a titanium dioxide extender in coated recycled paperboard and coated solid unbleached sulfate (SUS) beverage carrier stock.
[0034] It is still another object of the present invention to provide a novel purified natural zeolite pigment that can act as filler in newsprint to prevent print-through.
[0035] It is yet another object of the present invention to provide a novel purified natural zeolite pigment that can act as filler in specialty technical papers such as anti-tarnish, gas filtration, filter, and absorbent papers.
[0036] Another object of the present invention is to provide a novel purified natural zeolite pigment that can be used as a microparticulate retention aid.
[0037] Still another object of the present invention is to provide a novel purified natural zeolite pigment that can be used as a deinking aid in combination flotation-washing systems.
[0038] Yet another object of the present invention is to provide a novel purified natural zeolite pigment that can be used as a coefficient of friction (COF) control aid in recycled linerboard.
[0039] Another object of the present invention is to provide a novel purified natural zeolite pigment for use in a coating composition that has improved rheology compared to silica and other specialty pigments.
[0040] Still another object of the present invention is to provide a novel purified natural zeolite pigment for use in a coating composition that improves coater runnability.
[0041] It is yet another object of the present invention to provide a novel purified natural zeolite pigment for use in a coating composition that has decreased energy consumption in drying.
[0042] It is an object of the present invention to provide a novel composition for coating paper that has water slurries with a higher percentage of solids and good shear thinning rheology compared to existing compositions.
[0043] Another object of the present invention is to provide a novel composition for coating paper that has higher coating formulation solids compared to existing compositions.
[0044] Still another object of the present invention is to provide a novel composition for coating paper that has enhanced on-machine coating run ability and therefore enhanced production rates over existing compositions.
[0045] It is yet another object of the present invention to provide a novel composition for coating paper that has low Einlehner abrasion which results in reduced wear to process equipment and no metallic marks are left on the paper by the gripper bars.
[0046] Another object of the present invention is to provide a novel composition for coating paper that has a low bulk density.
[0047] Still another object of the present invention is to provide a novel composition for coating paper that has faster on-machine drying rates because of higher percent solid coatings than existing compositions which results in lower drying costs and reduced print smear.
[0048] Yet another object of the present invention is to provide a novel composition for coating paper that has a low crystalline silica content.
[0049] It is another object of the present invention to provide a novel composition for coating paper that coats with essentially no dusting.
[0050] It is still another object of the present invention to provide a novel composition for coating paper that has improved first pass retention in paper machine trials compared to existing compositions.
[0051] Another object of the present invention is to provide a novel composition for coating paper that has improved optical/reflective densities of four-color cyan, magenta, yellow, black (CMYK) ink jet print.
[0052] An additional object of the present invention is to provide a novel composition for coating paper that makes lighter coat weights possible because of higher internal void volume.
[0053] Still another object of the present invention is to provide a novel composition for coating paper with a slightly basic pH.
[0054] Yet another object of the present invention is to provide a novel composition for coating paper that has a high brightness of 90% or more.
[0055] Another object of the present invention is to provide a novel composition for coating paper that has a narrow particle size distribution with few fines.
[0056] An additional object of the present invention is to provide a novel composition for coating paper that improves ink jet print density.
[0057] It is yet another object of the present invention to provide a novel composition for coating paper that improves ink receptivity in printing papers.
[0058] Still another object of the present invention is to provide a novel composition for coating paper that has improved opacity.
[0059] An additional object of the present invention is to provide a novel composition for coating paper that has less soak-in and reduced roughening of the base sheet during application which results in a smoother coated sheet.
[0060] Another object of the present invention is to provide a novel composition for coating paper that allows higher operating speeds and higher production rates.
[0061] It is still an additional object of the present invention to provide a novel composition for coating paper that has the capability to coat on high speed paper machines rather than only on low speed off machine coating lines which reduces waste and costs.
[0062] In satisfaction of these and related objectives, Applicant's present invention provides a purified natural zeolite pigment composition for coating and/or filling of paper. Applicant's invention permits its practitioner to manufacture coated paper for use in ink jet printers that exhibits improved characteristics over existing uncoated and coated papers such as high print quality images and reduced cost. It also permits the practitioner to make other specialty and technical papers that exhibit quality and economic advantages over papers made with existing technology and commercially available materials.
BRIEF DESCRIPTION OF THE DRAWINGS
[0063] [0063]FIG. 1 is a graph of the dynamic contact angle versus time in seconds for coating compositions both with and without the zeolite pigment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0064] The processed zeolite used in the present invention has several specific characteristics as indicated in Table 2.
TABLE 2 Characteristics of Zeolite Pigment Samples Zeolite Pigment Zeolite Pigment Specification Sample 1 Sample 2 GE Brightness 8 % 94+ 90+ L 9 98.46 98.00 a 0.43 0.44 b 1.25 1.72 Yellowness Index 2.48 2.05 Particle Size μ, <D90 2.0 2.0 Einlehner Abrasion, mg loss 12 18 Loose Density, lbs./cu. ft. 8 8 Packed Density, lbs./cu. ft. 12 12 Refractive Index 1.48 1.48 Surface Area, sq. m./g. 40-50 40-50 Oil Absorption, lbs./100 lbs. 70-80 70-80 Density, g/cc 2.2 2.2 pH in Water 5.0 8.5 Cation Exchange Capacity 1.6-1.8 1.8-2.0 Brookfield Viscosity, 20 rpm @ 1000 cPs 1000 cPs 40% solids* Hercules Viscosity @ 1 dyne 1 dyne 1100 rpm* # when plus, greenness when minus and zero for gray; “b” represents yellowness when plus, blueness when minus, and zero for gray. This is referred to as TAPPI Test Method T 524 om-94 “Color of Paper and Paperboard (45°/0° Geometry).”
[0065] In evaluating the usefulness of the present zeolite, its material properties were tested. The first step was to determine whether the zeolite pigment could be dispersed using commonly available dispersants.
[0066] The colorants used in aqueous ink jet printer inks are anionic. A cationic material is used along with the pigment to fix the printed image to the paper. It is most desirable that an ink jet pigment be dispersible with a cationic dispersant with the dispersant providing dual functionality in the coating. The standard cationic dispersant for silica ink jet coatings is poly-dimethyl-diallyl ammonium chloride (DMDAAC) which has a common usage rate of 5% on dry pigment.
[0067] Evaluation of dispersants was done by adding a pre-weighed amount of pigment (enough to yield a 50% solids dispersion) to water under high shear using a Cowles Dissolver™ disperser. 10 The pigment was added slowly to the water until the viscosity of the pigment began to substantially increase. This occurred around the 46% solids point. The dispersant being evaluated was then added to drop the viscosity, and the remainder of the pigment was added. Samples of the pigment dispersion were taken for Brookfield viscosity and Hercules high-shear rheology testing. The final solids content was determined by oven drying a sample of the pigment dispersion.
[0068] The present zeolite was successfully dispersed with 5% DMDAAC to provide 50.7% slurry solids with Brookfield viscosity of 414 cPs at 100 rpm with a No.4 spindle. The 20-rpm viscosity at 50.7% solids was 1520 cPs. The lower viscosity at 100 rpm indicates that the present zeolite pigment has a shear thinning rheology which is highly desirable for application on blade, rod, and metering size press coaters. With silica pigments, such as Grace-Davison's Sylojet™, J. M. Huber's Optisil™ or ICI Crosfield's Gasil®, use of 5% DMDAAC provides dispersion at <30% maximum solids. The lower solids of silica dispersions severely limit application solids for formulated coating colors. Silica pigments are also known to be dilatant or shear thickening, which causes running problems on blade and rod coaters. The rheology of silica pigments makes it impractical to run them in on-machine metering size press coatings at solids content high enough to prevent soak-in and binder migration. Hercules high-shear rheograms of the present zeolite pigment confirmed that the present pigment provides rheology suitable for good coater runnability and sheet surface quality.
[0069] For use in applications other than ink jet printing—for example as an adjunct pigment in coating formulations including kaolin clay, calcium carbonate and titanium dioxide—it is desirable that the zeolite pigment be dispersible with a standard dispersant used for conventional pigments. The present zeolite was also successfully dispersed with 2% AMP-95™ (2-amino, 2-methyl, 1-propanol) 11 to provide a stable dispersion at 50.34% solids with Brookfield viscosity of 470 cPs at 100 rpm with a No. 4 spindle. The 20-rpm viscosity at 50.34% solids was 1680 cPs. Hercules high-shear rheograms showed the AMP-95™ zeolite dispersion to be thixotropic and shear thinning—desirable rheology for paper and paperboard coating.
[0070] Drawdowns 12 of pure dispersed zeolite pigment of the present invention on a 76.6% brightness base sheet gave 86.0% GE brightness.
[0071] Drawdowns were made with various ratios of pigment to PVOH (polyvinyl alcohol) binder to determine the CPVC. 13 The CPVC was found to be 50%, that is a pigment to binder ratio of 1:1.
[0072] Dusting was also evaluated. Dusting 14 (sometimes called “rub off” or “chalking” is a major potential problem with ink jet papers made with silica pigments. Many coaters find that they must add polyvinyl pyrolidone (PVP) to control dusting. Drawdowns were made with the present zeolite and polyvinyl alcohol at pigment binder ratios up to 14:1 to evaluate the dusting potential. No PVP was added. The present zeolite pigment coatings did not dust at pigment to binder ratios up to 14:1, which provides a significant performance advantage.
[0073] The results showed that the present processed zeolite pigment could act as an ink jet coating pigment.
[0074] Laboratory coating formulation experiments were performed to determine the viscosity at highest obtainable coating solids. The present zeolite was dispersed with 5% DMDAAC at 50.7% solids. A 30% solution of Airvol® 203 PVOH 15 was prepared by dispersing the granules in cold water, heating to 85° C. and holding at 85° C. for 30 minutes. The dispersed zeolite slurry and PVOH solutions were blended to obtain pigment to binder ratios of 2:1, 4:1, 6:1 and 8:1 with no dilution water added.
[0075] Viscosity determination of the coating formulations was made using a Brookfield RVT viscometer with a #5 spindle. The data obtained from these experiments is contained in Table 3a and can be compared to data from three major suppliers of silica pigments as contained in Table 3b and to data from Engelhard™ regarding a modified kaolin based pigment as contained in Table 3c.
TABLE 3a Brookfield Viscosity of Zeolite Formulations Pigment:Binder Ratio % Coating Solids 20 rpm 100 rpm 2:1 40.17 4000 1750 4:1 41.87 5400 1972 6:1 43.09 6760 2100 8:1 45.93 7880 2368
[0076] [0076] TABLE 3b Coating Formulation Solids Content from Silica Suppliers' Data Sheet and/or the sheet surface. Coating pigment particles are easily dislodged from the coated sheet surface by rubbing and/or when the coated sheet is folded, slit, or die cut. Airvol ® 203 is a partially hydrolyzed (87.0-89.0% hydrolysis) polyvinyl alcohol produced by Air Products and Chemicals, Inc. Allentown, PA. Supplier Grace-Davison J. M. Huber ICI Crosfield Product Sylojet ™ Optisil ™ Gasil □ Pigment:Binder Ratio 2.49:1 1.00-1.67:1 2.5:1 % Solids 18.4 14-18 18
[0077] [0077] TABLE 3c Coating Solids Recommendation from Engelhard Data Sheet Supplier Engelhard Product Digitex ™ Pigment:Binder Ratio 2.5:1 Coating % Solids 30 to 33%
[0078] As can be seen from these data, the present zeolite pigment provides coating color solids more than twice as high as any of the currently used silica pigments. It provides coating solids 21% higher than the highest coating solids claimed from the Engelhard Digitex™ hybrid kaolin pigment. The present zeolite pigment provides shear-thinning rheology to facilitate application by blade, rod, or metering size press coaters. The higher solids attainable with the zeolite pigment of the present invention provide substantial operating benefits to producers of ink jet papers including less soak in and reduced roughening of the base sheet during application resulting in a smoother coated sheet, improved coater runnability, decreased energy consumption in drying, higher operating speeds and higher production rates and capability to coat on high speed paper machines rather than only on low speed off machine coating lines which reduces waste and costs.
[0079] Test printing of the drawdowns on Canon and Epson ink jet printers showed that density improved as the pigment to binder ratio was decreased from 8:1 to 2:1. At 2:1 pigment to binder ratio, the present zeolite pigment drawdowns came close to the value for commercial papers Weyerhaeuser Satin Ink Jet™ and International Paper Great White™ Premium Matte Ink Jet Paper. The commercial papers had been produced on full-scale machinery with optimized formulations and calendered to improve performance. Due to these results, it was determined that pilot coating trials should be performed.
[0080] The zeolite of the present invention was evaluated as a coating pigment and filler with an emphasis on coating ink jet papers as a replacement for silica. For the pilot coating, Cylindrical Laboratory Coater (CLC) trials were performed. The CLC 16 is a laboratory device that simulates coating at commercial machine speeds while consuming only small amounts of coating materials. It provides not only coated paper samples for evaluation, but also indications of runnability in commercial production. The coating experiments were performed using the zeolite of the present invention as the sole pigment with polyvinyl alcohol binder at varying pigment to binder ratios. More specifically, the experimental design used was based on E-Chip using the following parameters: 1) pigment: binder ratios of 2:1, 5:1, and 8:1; 2) polyvinyl alcohol types from Air Products™ including Airvol® 103 (fully hydrolyzed 98.0-98.8% hydrolysis) and Airvol® 203 (partially hydrolyzed 87.0-89.0% hydrolysis); 3) Amp 95™ and DMDAAC as dispersants; 4) coat weights of 6, 9 and 12 grams/square meter; 5) 23 combinations of conditions; and 6) 29 total runs. The CLC trials were run at 2500-3600 feet/minute. Blade metering was done with 0.015-inch thick coating blade and a 0.018-inch thick backing blade using a 0.4-inch extension. The results of these trials are indicated in Table 4.
TABLE 4 Results of Cylindrical Laboratory Coater (CLC) Pilot Trials Pigment:binder ratio PVOH Speed Runnability/Coverage 2:1 203 2000 Excellent 2:1 203 2500 Excellent 6:1 203 2000 Excellent 6:1 203 3000 Good 6:1 203 3200 Good 6:1 203 3600 Uneven 8:1 203 2000 Excellent 8:1 203 2800 Good 8:1 203 3200 Uneven at start 8:1 103 3200 Good 8:1 103 3400 Uneven
[0081] The trials demonstrated that excellent runnability and coverage could be achieved at 2500 feet/minute, a speed substantially higher than the 900-1500 feet/minute common on off-machines producing coated ink jet papers. Optimization of the coating formulation of the present invention can increase the speeds at which the present zeolites can be used to coat ink jet paper.
[0082] In evaluating the present zeolite for use in coating ink jet paper it was important to take into account the effects of calendering 17 . Commercial coated ink jet papers are usually soft nip calendered to improve image density. In order to determine the effects of calendering, test prints were made with both uncalendered and laboratory calendered CLC coated papers. As expected, calendering improved print density. The samples were printed on three different commercial ink jet printers, Canon BJ500™, HP 932C™, and Epson 800™. Two commercial premium coated ink jet papers, Weyerhaeuser Satin Ink Jet™ and International Paper Great White™ Premium Matte Ink Jet Paper, and a plain paper specially surface sized for ink jet printing were printed as bench marks. The ink densities of the printed sample were compared using an X-Rite densitometer. The ink densities of the present zeolite coated papers were found to be statistically equal to or better than the premium commercial papers for all three printers. The best quality was achieved at 2:1 pigment to binder ratio. The results of this experiment are contained in Table 5, which presented the data for the laboratory-calendered samples. Laboratory calendering increased densities of all four colors on all three printers. No attempt was made to optimize the zeolite formulations in contrast to the commercial silica coated papers that are made with optimized formulations and manufacturing procedures. In commercial practice, each paper manufacturer will optimize its formulation to match the characteristics of the base paper to be coated and the coating equipment to be used.
TABLE 5 Printability Tests of CLC Coated with Zeolite CLC SAMPLES (Flexible Blade Coated) Airvol 203 2:1 Pigment to Binder (35% solids) Average Reflective Densities-X-Rite Densitometer Cyan Magenta Yellow Black Printed on HP932C (600 × 600 dpi) CLC Coated Samples Coat Weight-gsm 3.6 1.334 1.398 0.962 1.536 4.6 1.312 1.412 0.974 1.522 5.4 1.316 1.338 0.964 1.498 8.8 1.302 1.404 0.958 1.566 13.9 1.354 1.438 0.980 1.530 Commercial Paper Control Samples Great White 1.110 1.162 0.896 1.494 Weyerhaeuser 1.408 1.478 1.026 1.612 Plain Multi-Purpose 1.100 1.150 0.900 1.500 Printed on EPSON 800 series (720 × 1440 dpi) CLC Coated Samples Coat Weight-gsm 3.6 0.988 1.186 0.890 1.514 4.6 1.054 1.190 0.906 1.530 5.4 1.016 1.190 0.898 1.548 8.8 1.042 1.184 0.892 1.498 13.9 1.048 1.200 0.898 1.522 Commercial Paper Control Samples Great White 1.030 1.250 0.960 1.636 Weyerhaeuser 0.888 1.020 0.860 1.280 Plain Multi-Purpose 0.946 1.036 0.836 1.306 Printed on CANON BJC 5000 (720 × 1440 dpi) CLC Coated Samples Coat Weight-gsm 3.6 1.524 1.568 0.934 1.420 4.6 1.532 1.422 0.898 1.410 5.4 1.474 1.510 0.908 1.396 8.8 1.548 1.602 0.932 1.500 13.9 1.468 1.608 0.946 1.530 Commercial Paper Control Samples Great White 1.438 1.486 0.972 1.560 Weyerhaeuser 1.146 1.308 0.866 1.748 Plain Multi-Purpose 0.978 1.052 0.802 1.448
[0083] In addition to its high quality performance, the zeolite pigment provides other significant advantages compared to silica pigments. The zeolite pigment produces higher slurry solids with 50% for zeolite compared to 30% maximum for silica and 42-45% for specialty hybrid kaolin pigments which is a significant advantage in coating preparation. In addition, the zeolite pigment has higher coating solids with 36-40% for zeolite pigment compared to <20% for silica and 30-33% for specialty hybrid kaolin pigments which means significantly lower cost for drying and higher coating line operating speeds. Coating at higher solids not only saves energy and increases production rate, but also results in a higher quality coated surface. The zeolite pigment also has a low binder demand. Coatings prepared at pigment-to-binder ratios as high as 14:1 did not show signs of cracking orflaking. With silica pigment, it is essential to use polyvinyl alcohol, which is the strongest available binder. An inexpensive starch cobinder can be used with the zeolite pigment of the present invention. This capability can be a key to making a higher fidelity mid-priced coated ink jet paper. The zeolite pigment additional has excellent rheology for use in various types of coaters including on-machine metering size presses. Silica coatings must be applied on low speed (1000 to 1500 feet/minute) off machine coaters, which significantly increases costs. Coating with the zeolite pigment of the present invention on-machine at speeds in the 3000-4000 feet/minute range combined with elimination of the extra costs associated with off machine coating can facilitate serving a larger market.
[0084] The best ink jet densities were obtained using polyvinyl alcohol binder at 2:1 pigment to binder ratio. Density was reduced at higher pigment-to-binder ratios. This confirms the function of the superior pigment void volume of the zeolite pigment. The implication of this is that the zeolite pigment of the present invention can be effective in several applications including improvement of flexo ink vehicle receptivity to prevent smudging in direct post print of corrugated containers and use of the pigment as filler in newsprint and uncoated ground wood papers to eliminate print-through. Calcined kaolin, silicas, and silicates currently used in this second application are not cost effective.
[0085] Changes in retailing are driving the need for high quality multi-color printing on corrugated containers. In-line printing via flexography 18 without drying is the current preferred process. If the ink vehicle is not rapidly absorbed the surface smudges. Use of coating pigments with good void volume can prevent smudging. The best performing current pigments are calcined kaolin and calcium carbonate; however, both are abrasive. Abrasive coating pigments make the surface prone to metal marking producing gray streaks on the printed image. Use of the zeolite pigment of the present invention which is nonabrasive as 10 to 15% of the total coating pigment should provide the needed ink vehicle absorption without metal marking.
[0086] Coating drawdowns on linerboard were performed to determine the impact of the zeolite pigment on dynamic contact angle wetability, which is a good predictor of performance in direct print flexo on corrugated. Linerboard was precoated with 10 gsm of precoat formulation. The precoated samples were then top coated with 15 gsm of a standard formulation and also a formulation substituting 10 parts ZOBrite pigment.
[0087] The coating formulations used were:
Precoating-Applied at 10 gsm Dry Parts Component 100 Exsilon ™ chemically structured kaolin 15 Acetate latex-Rohm & Haas 3103 3 Pro-Cote ® 4200 cold water dispersible soy protein 0.9 AZC crosslinker-HTI AZ-Cote ® 5800 M 0.1 Polyacrylate dispersant-Dispex ® N-40 0.28 Ammonia-as required for pH 8.5
[0088] [0088] Top Coat Without Zeolite-Applied at 15 gsm Dry Parts Component 40 No. 1 high brightness coating clay-Ultra-White 90 40 Fine ground calcium carbonate-Hydrocarb ® 90 20 Titanium dioxide-rutile-TiPure ® RPS Vantage 14 Acetate latex-Rohm & Haas 3103 4 Pro-Cote 4200 cold water dispersible soy protein 0.7 Calcium stearate lubricant-Nopcote ® C-104-HS 1.6 AZC crosslinker-HTI AZ-Cote ® 5800 M 0.1 Polyacrylate dispersant-Dispex ® N-40 0.42 Ammonia-as required for pH 8.5
[0089] [0089] Top Coat With Zeolite-Applied at 15 gsm Dry Parts Component 10 Zeolite pigment 35 No. 1 high brightness coating clay-Ultra-White 90 35 Fine ground calcium carbonate-Hydrocarb ® 90 20 Titanium dioxide-rutile-TiPure ® RPS Vantage 14 Acetate latex-Rohm & Haas 3103 4 Pro-Cote 4200 cold water dispersible soy protein 0.7 Calcium stearate lubricant-Nopcote ® C-104-HS 1.6 AZC crosslinker-HTI AZ-Cote ® 5800 M 0.1 Polyacrylate dispersant-Dispex ® N-40 0.42 Ammonia-as required for pH 8.5
[0090] The dynamic contact angle of the coated samples was measured and the results shown in Table 6 and FIG. 1. It was found that substitution of 10 parts zeolite in the top coat formulation provided a significant improvement in dynamic contact angle wetability. This shows the zeolite provides the capability to capture flexo ink in direct print (without drying) on a flexo-folder-gluer or case-making machine. The top coat coated with the zeolite composition was evaluated for metal marking by rubbing the surface with a nickel coin. No metal marking was observed.
TABLE 6 Dynamic Contact Angle Measurements of Coated Linerboard Time No Time 10 Parts Seconds Zeolite Seconds Zeolite 0.0 63.42 0.0 51.91 22.5 62.52 6.3 51.53 45.0 60.69 54.5 51.07 57.0 59.27 67.1 49.85 64.5 58.98 79.8 50.51
[0091] Further trials were run on the CLC to determine the effect of substitution of the present zeolite for No. 1 high brightness clay in a standardized paperboard topcoat formulation:
Standardized Topcoat Formulation Dry Parts Component 40 No. 1 high brightness coating clay-Ultra-White 90 ® 40 Fine ground calcium carbonate-Hydrocarb ® 90 20 Titanium dioxide-rutile-TiPure ® RPS Vantage 14 Acetate latex-Rohm & Haas 3103 4 Pro-Cote 4200 cold water dispersible soy protein 0.7 Calcium stearate lubricant-Nopcote ® C-104-HS 1.6 AZC crosslinker-HTI AZ-Cote ® 5800 M 0.1 Polyacrylate dispersant-Dispex ® N-40 0.42 Ammonia-as required for pH 8.5
[0092] The control topcoat was made up at 55% solids and pH 8.5. Brookfield viscosity was 600 cPs using a No. 6 spindle at 100 rpm. Experimental coatings were made by substituting 5, 10, 15 and 20 parts zeolite pigment for No. 1 coating clay. These coatings were also prepared at 55% solids and pH 8.5. Each of the coatings was evaluated on a Hercules high shear rheometer using Bob E, 6600 rpm and spring set 200. Rheograms showed all coatings to be shear stable. Torque at 6600 maximum rpm for each of the coatings was:
Parts Zeolite Torque-kilodyne-cm 0 1750 5 1800 10 2128 15 2053 20 2507
[0093] The topcoats were applied to precoated recycled paperboard using a CLC laboratory coater with a blade application and a target coat weight of 4 to 5 pounds per 1000 square feet. Three replicates were done for the control and each of the four experimental coatings for a total of 15 samples. Each sample was then calendered on a hard/soft nip calender at 600 pli for three passes before evaluation.
[0094] The coated and calendered unprinted paperboard samples were tested for dynamic contact angle. The results of the dynamic contact angle showed that the 15 parts of zeolite had the best absorption followed closely by the 5 and 10 parts of zeolite pigment. The more rapid drop of the contact angle with the specimens containing zeolite pigment shows that the zeolite pigment adds a greater absorption rate into the coated surface. Increasing the zeolite pigment fraction to 20 parts did not provide better absorption than achieved with 15 parts zeolite pigment.
[0095] The coated and calendered unprinted paperboard samples were tested for brightness with the following results:
Parts Zeolite Brightness 0 82.1 5 83.8 10 84.1 15 80.5 20 80.5
[0096] There was a gain in brightness from the control (0 parts zeolite pigment) with 5 and 10 parts of zeolite pigment, then the brightness dropped with higher levels of zeolite pigment. This is encouraging for two reasons: (1) there is an increase in brightness with the addition of small amounts of zeolite pigment and (2) this increase in brightness could allow for more intense calendering of the formulations with 5 and 10 parts zeolite pigment to increase gloss.
[0097] The coated and calendered paperboard samples were printed on a GMS Flexo Print Proofer. Ink density was measured with an X-Rite densitometer. Ink density for all samples was in the range of 2.2-2.3; a density change of 2.0 points is considered significant. There is no apparent change in ink density with increasing amounts of zeolite pigment substitution. This is important in that the coated surface with the addition of zeolite pigment allows for increased absorptivity of the ink vehicle without absorbing the ink pigment into the sheet. These results are also an indication that inclusion of the zeolite pigment would be useful in improving water-based gravure printing quality.
[0098] Due to increasing postage and handling costs, the basis weight of newsprint and other uncoated groundwood printing papers continues to be reduced. At the same time, newspapers are doing more color process printing. The thinner sheets are unfortunately prone to print-through. Use of a porous filler pigment cannot only help to reduce print-through, but can also increase opacity. Newsprint is made at acid pH which prevents the use of calcium carbonate for this application since it provides too alkaline of an environment. Calcined clay works in preventing print-through, but it is difficult to retain and is also abrasive. The current products of choice are lower grade silicas and precipitated silicates, but the use of the products is not cost effective. The zeolite pigment of the present invention is not only nonabrasive, but also cost-effective.
[0099] Pilot paper machine trials were run comparing the use of the zeolite of the present invention to precipitated calcium carbonate (PCC) as filler. The trials showed significant advantages of the present zeolite pigment as filler. These pilot machine filler trials were run without use of retention aid polymers. It was found that the filler retention for the present zeolite was 2.5 to 4 times as high as PCC which facilitates running a cleaner wet end with improved sheet formation and uniform optical properties. The significantly higher retention achieved with the zeolite of the present invention is an indication that it can perform well as a substitute for silica in microparticulate retention systems. Silicas currently used in this application are not cost effective. The improved retention of the zeolite pigment is an indication that it would be useful as an alternative to costly silica as a deinking aid.
[0100] In addition, porosity tests showed that the present zeolite produced a more open sheet, which would facilitate the use of this pigment in specialty gas filtration papers and anti-tarnish papers. It was also found that the zeolite pigment of the present invention produced papers that had higher tensile strength and tensile energy absorption or stretch. Papers filled with the present zeolite also had a higher coefficient of friction, which decreases the likelihood of misfeed and jams in copiers and also improves performance in converting equipment and print shops. The zeolite of the present invention can also be useful as a frictionizer for coefficient of friction control in recycled linerboard.
[0101] The capability of the zeolite pigment to reduce print-through was evaluated by printing samples from the pilot paper machine trials on a proof press and visually inspecting them for evidence of print show-through. The control sample with no filler showed severe print-through. The sample filled with 100 pounds of zeolite pigment (4.59% measured ash content) showed no evidence of print-through. Samples filled with PCC at levels up to 250 pounds per ton showed little improvement over the unfilled control with regard to print-through. The superior performance of the zeolite pigment in minimizing print-through is an indication that it would be useful in production of ultra lightweight-coated publication papers.
[0102] A short pigmented size press coating trial was performed during the pilot paper machine run. The zeolite of the present invention was formulated in a 2:1 ratio with size press starch and applied via conventional pond size press. Runnability was good and the sheet was free from dusting. Samples of the pigmented size press coated paper were printed on the three ink jet printers. This preliminary trial work showed that the zeolite of the present invention can be used as pigment for size press coating.
[0103] Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limited sense. Various modifications of the disclosed embodiments, as well as alternative embodiments of the inventions will become apparent to persons skilled in the art upon the reference to the description of the invention. It is, therefore, contemplated that the appended claims will cover such modifications that fall within the scope of the invention.
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A high performance purified natural zeolite pigment composition for use in papermaking and paper coating is disclosed. Use of the pigment facilitates manufacture of coated ink jet and digital printing papers with improved quality and economics. The novel zeolite pigment composition can also be used as a supplementary pigment to improve the properties of coated paper and paperboard for flexographic and water-based gravure printing. When used as filler, the novel zeolite pigment composition is readily retained and eliminates print-through in uncoated papers. The novel zeolite pigment is low in abrasion and provides improved coefficient of friction. The novel zeolite pigment is also useful as a microparticulate retention aid in papermaking and as an additive to improve the performance of deinking processes.
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BACKGROUND OF THE INVENTION
The present invention relates to the field of air/fuel ratio control devices for internal combustion engines such as those internal combustion engines used for automotive vehicles, and more particularly relates to the field of such air/fuel ratio control devices for internal combustion engines which are equipped with double barreled carburetors in their fuel intake systems and three way catalytic converters in their exhaust systems.
Three way catalytic converters for internal combustion engines are per se well known in various different forms. Such a three way catalytic converter is capable of converting HC, CO, and other products of incomplete combustion in the hot exhaust gases of the internal combustion engine into harmless end products by an oxidizing reaction, and also of simultaneously converting nitrogen oxides (so called NOx) in the exhaust gases into harmless end products by a reducing reaction, provided that the air/fuel ratio of the exhaust gases passing into said three way catalytic converter is maintained within a rather narrow range about the stoichiometric condition. If, however, the air/fuel ratio of the exhaust gases passing into said three way catalytic converter wanders towards the lean side of stoichiometric, then although the above detailed oxidizing reaction for converting HC, CO, and other products of incomplete combustion in the hot exhaust gases of the internal combustion engine into harmless end products continues, the reducing reaction for converting nitrogen oxides in the exhaust gases into harmless end products will substantially cease; and, if the air/fuel ratio of the exhaust gases passing into said catalytic converter wanders towards the rich side of stoichiometric, then although the reducing reaction for converting nitrogen oxides in the exhaust gases of the internal combustion engine into harmless end products continues, the oxidizing reaction for converting HC, CO, and other products of incomplete combustion in the hot exhaust gases into harmless end products will substantially cease.
It is possible to control the air/fuel ratio of the exhaust gases passing into the three way catalytic converter within a narrow range about the stoichiometric condition by controlling the air/fuel ratio of the air-fuel mixture being supplied to the internal combustion engine through its intake system within a narrow range about the stoichiometric condition, and therefore conventionally many different sorts of fuel/air ratio control systems have heretofore been proposed which have as their goal maintaining the air/fuel ratio of the air-fuel mixture being supplied to the internal combustion engine close to the stoichiometric condition.
A typical such prior art system has an oxygen sensor fitted to the exhaust manifold of the internal combustion engine, upstream of the three way catalytic converter, so as to sense the presence of oxygen in the exhaust gases therein. The signal from this oxygen sensor is then sent to a device which provides extra air into the intake system of the engine at some point therein. In this case, the basic air/fuel ratio of the air-fuel mixture provided by the carburetor of the internal combustion engine is set to be rather on the rich side of stoichiometric, and thus by addition of a proper amount of extra air to the intake system and air/fuel ratio of the air-fuel mixture provided to the internal combustion engine may be controlled to be substantially the stoichiometric air/fuel ratio. Conventionally, the extra air can either be added directly into the intake manifold of the engine, downstream of the carburetor; but it is better from the point of view of mixing of air and of fuel for the extra air to be provided into a passage of the carburetor as an additional amount of bleed air to be mixed with the fuel being provided by the carburetor, in a per se well known fashion. In either case, by feedback control performed by the extra air control device based upon the signal from the oxygen sensor, the air/fuel ratio of the air-fuel mixture provided into the cylinders of the internal combustion engine can be satisfactorily controlled to be substantially the stoichiometric air/fuel ratio, and thereby the air/fuel ratio of the exhaust gases passing into the three way catalytic converter can be satisfactorily maintained within a narrow range about the stoichiometric condition.
This kind of prior art feedback system is effective in the case of a single barreled carburetor, but in the case of a double barreled carburetor, the use of which is becoming more and more frequent nowadays, certain difficulties tend to arise which will now be outlined.
Such a double barreled type of carburetor is provided with a main or primary air intake passage and fuel supply system and a secondary air intake passage with its own fuel supply system. A primary throttle valve is mounted in the primary air intake passage so as to control its opening amount, and a secondary throttle valve is mounted in the secondary air intake passage so as to control its opening amount. Conventionally the primary throttle valve is opened and closed according to the depression of an accelerator pedal or the like of a vehicle to which the internal combustion engine incorporating the carburetor is fitted, and the secondary throttle valve remains closed until the primary throttle valve is opened to a predetermined throttle opening amount, and then, provided that the intake air flow is greater than a certain predetermined air flow amount, opens progressively as the primary throttle valve opens beyond said predetermined opening amount.
The question therefore arises as to at what place in such a double barreled carburetor with two fuel supply systems the extra bleed air, described above, regulated by the extra air control device based upon the signal from the oxygen sensor, should be injected. A system such as for the primary fuel system of the carburetor to have one bleed air supply system incorporating its own primary extra or bleed air control device and for the secondary fuel system to have its own independent secondary bleed air supply system also incorporating its own secondary extra or bleed air control device (the two systems may of course share the same oxygen sensor in the exhaust system of the engine) would solve this question satisfactorily. In this case, air/fuel ratio control would be performed for both the primary fuel system and also the secondary fuel system independently, and accordingly both the air/fuel ratio of the air-fuel mixture produced by the primary fuel system would be kept within a reasonably small range around the stoichiometric value and also the air/fuel ratio of the air-fuel mixture produced by the secondary fuel system would be kept within a reasonably small range around the stoichiometric value. Further, during transient operating conditions such as quick opening or closing of the primary and secondary throttle valves the deviations from the approximately stoichiometric air/fuel ratio of the air-fuel mixture provided by the primary and secondary fuel systems would not be very great. However, the disadvantages of such a system are that two control devices are necessary, and this causes the amount of mechanism to be large, and the cost and the bulk of the system also becomes excessive.
Further, as a general principle, since in fact the secondary throttle valve is not actually opened very often in normal vehicle operation, it is really rather wasteful to provide a special secondary extra or bleed air control device just for the secondary air bleed control system.
An alternative system that has been practiced in the prior art is, therefore, for the primary fuel system of the carburetor to have a bleed air supply system incorporating a primary bleed air control device, and for air bleeding control to be carried out only on the primary fuel supply system of the carburetor, and not on the secondary fuel supply system at all. This system of course avoids the disadvantages outlined above of high cost and duplication of mechanism, and of course when the primary throttle valve is opened but the secondary throttle valve is not opened the regulation of the amount of bleed air, in the above mentioned feedback manner, is performed properly. However, when both the primary throttle valve is opened and also the secondary throttle valve is opened, because the air/fuel ratio of the air-fuel mixture supplied by the carburetor as a whole must be kept substantially at the stoichiometric value by the above described feedback operation, with air bleeding only being performed into the primary fuel supply system, the air/fuel ratio of the air-fuel mixture supplied by the primary fuel supply system will be substantially higher, i.e. leaner, than stoichiometric, while the air/fuel ratio of the air-fuel mixture supplied by the secondary fuel supply system needs to be maintained less, i.e. richer, than stoichiometric.
Now, provided that the air-fuel mixture which is being produced by the primary fuel supply system is well mixed with the air-fuel mixture which is being produced by the secondary fuel supply system before being distributed between the cylinders of the engine, under normal operating conditions of the engine the system will operate correctly in the feedback manner outlined above. However, when for example the vehicle incorporating the engine is quickly decelerated and the accelerator pedal thereof is released quickly from the above described high load condition in which both the primary throttle valve and also the secondary throttle valve are open, i.e. the secondary throttle valve is quickly closed to its completely closed position and the primary throttle valve is still opening at an opening amount substantially less than the aforementioned predetermined opening amount, then the operation of the secondary fuel supply system, which was supplying air-fuel mixture of air/fuel ratio substantially richer than stoichiometric, stops immediately, but the operation of the primary fuel supply system, which was supplying air-fuel mixture of air/fuel ratio substantially leaner than stoichiometric, continues; and, during the inevitable time delay interval before the above described feedback system brings the opening of the bleed air control valve to the equilibrium opening amount which provides an air/fuel ratio for the air-fuel mixture being supplied by the primary fuel system of approximately stoichiometric (this time delay is inevitable because of the time taken for the physical elements of the bleed air control valve to move to their new positions, as well as other factors), the air/fuel ratio of the air-fuel mixture being supplied by the primary fuel supply system is the same as it was while the secondary fuel supply system was operating, i.e. is substantially larger or leaner than stoichiometric; and during this time delay interval therefore a substantially leaner air-fuel mixture than stoichiometric is supplied to the internal combustion engine. In this over lean engine operation condition the very undesirable consequences are liable to occur of deterioration of engine drivability and also of increase in the emission of nitrogen oxides or NOx in the exhaust gases of the engine, due to the poor operation of the three way catalytic converter in its mode of removing nitrogen oxides from the exhaust gases by a reducing reaction in the state of the exhaust gases of containing an excess of oxygen, i.e. of being over lean.
SUMMARY OF THE INVENTION
Accordingly, it is the primary object of the present invention to provide an air/fuel ratio control system for an internal combustion engine equipped with a double barreled carburetor and a three way catalytic converter, incorporating only one air bleed control valve, which can provide sufficiently good regulation of the air/fuel ratio delivered by the carburetor, even during rapid changing of the load on the internal combustion engine.
It is a further object of the present invention to provide an air/fuel ratio control system for an internal combustion engine equipped with a double barreled carburetor and a three way catalytic converter, incorporating only one air bleed control valve, in which the air/fuel ratio of the exhaust gases of the internal combustion engine is kept fairly near stoichiometric even when the accelerator pedal of the vehicle incorporating the engine is abruptly released from a position thereof in which both the primary throttle valve and also the secondary throttle valve of the carburetor are open to a position in which only the primary throttle valve is at all open.
It is a further object of the present invention to provide an air/fuel ratio control system for an internal combustion engine equipped with a double barreled carburetor and a three way catalytic converter, incorporating only one air bleed control valve, in which the air/fuel ratio of the exhaust gases of the internal combustion engine does not become so high (i.e. lean) as to cause improper functioning of said three way catalytic converter in its mode of purifying the exhaust gases of nitrogen oxides, even during abrupt deceleration of the vehicle incorporating the engine.
It is a further object of the present invention to provide an air/fuel ratio control system for an internal combustion engine equipped with a double barreled carburetor and a three way catalytic converter, incorporating only one air bleed control valve, which operates in the above described feedback fashion to keep the air/fuel ratio of the air-fuel mixture supplied to the engine near the stoichiometric one when the internal combustion engine is operating, even during rapid changing of the load on the internal combustion engine.
It is a further object of the present invention to provide an air/fuel ratio control system for an internal combustion engine equipped with a double barreled carburetor and a three way catalytic converter, which is cheap to manufacture.
It is a further object of the present invention to provide an air/fuel ratio control system for an internal combustion engine equipped with a double barreled carburetor and a three way catalytic converter, which is simple in operation.
It is a further object of the present invention to provide an air/fuel ratio control system for an internal combustion engine equipped with a double barreled carburetor and a three way catalytic converter, which is reliable in operation.
According to the present invention, these and other objects are accomplished by, for an internal combustion engine, comprising: (a) an exhaust system through which exhaust gases are vented; and (b) a carburetor, comprising: (b1) a primary fuel supply system comprising a primary intake passage and a primary throttle valve which controls the air flow resistance of said primary intake passage; (b2) a secondary fuel supply system comprising a secondary intake passage and a secondary throttle valve which controls the air flow resistance of said secondary intake passage, so as to keep said secondary intake passage closed when said primary throttle valve is opened to less than a certain predetermined opening amount, and so as progressively to open said secondary intake passage as said primary throttle valve is opened beyond said predetermined amount, if and only if the intake air flow through said carburetor is greater than a certain predetermined amount; (b3) a primary main fuel supply nozzle opening into said primary intake passage, fuel being supplied to said primary main fuel supply nozzle so as to be sucked therefrom into said primary intake passage by the depression in said primary intake passage, when air is flowing through said primary intake passage; and (b4) a secondary main fuel supply nozzle opening into said secondary intake passage, fuel being supplied to said secondary main fuel supply nozzle so as to be sucked therefrom into said secondary intake passage by the depression in said secondary intake passage, when air is flowing through said secondary intake passage; an air/fuel ratio control system, comprising: (c) a sensor, mounted to said exhaust system, which detects the concentration of a component in the exhaust gases in said exhaust system, and which produces a sensor electrical signal representative thereof; (d) an electrical control unit, which receives said sensor electrical signal from said sensor, and which produces a valve control electrical signal based thereon; (e) an air bleed control valve which receives said valve control electrical signal from said electrical control unit, comprising: (e1) an air inlet open to air at substantially atmospheric pressure, and (e2) an air outlet; (e3) said air bleed control valve varying its resistance to flow of air from said air inlet to said air outlet, according to said valve control electrical signal; (f) a primary air bleed path system, leading from said air outlet of said air bleed control valve, which supplies primary bleed air into the fuel which is being supplied through said primary main fuel supply nozzle into said primary intake passage; (g) a secondary air bleed path system, leading from said air outlet of said air bleed control valve, which supplies secondary bleed air into the fuel which is being supplied through said secondary main fuel supply nozzle into said secondary intake passage; and (h) a one way air valve, comprising an inlet and an outlet, fitted in said secondary air bleed path system so as to allow air flow in said secondary air bleed path only in the direction from said air outlet of said air bleed control valve towards said secondary main fuel supply nozzle.
Let us assume that said primary air bleed path system has an air flow resistance R 1 , said secondary air bleed path system has an air flow resistance R 2 , and said bleed control valve provides an air flow resistance Rch 1 when the carburetor is operating at a high load with both said primary and said secondary throttle valves being substantially opened. In this case, the amount of bleed air supplied through said first and second air bleed path systems is inversely proportional to Rch 1 +R 1 R 2 /(R 1 +R 2 ), provided that the intake manifold vacuum remains at a constant value.
On the other hand, if the same amount of bleed air to be supplied only through a single air bleed path system provided in a conventional two barrel type carburetor, assuming that said single air bleed path system has an air flow resistance R 0 and that the bleed control valve which controls said single air bleed path system provides an air flow resistance Rch 2 at that time, then:
Rch.sub.2 +R.sub.0 =Rch.sub.1 +R.sub.1 R.sub.2 /(R.sub.1 +R.sub.2)(*)
Now, if the engine load is abruptly decreased from the above operating condition to a lower load condition in which said primary throttle valve is set at an opening amount less than said predetermined opening amount and therefore said secondary throttle valve is set at its completely closed position, said air bleed control valve in the carburetor, according to the present invention, and that of the abovementioned conventional carburetor, still provide for a certain delay time the air flow resistances of Rch 1 and Rch 2 , respectively. During this delay time, the amount of bleed air supplied now only through said primary air bleed path system, according to the present invention, will be inversely proportional to Rch 1 +R 1 , whereas the amount of bleed air supplied through said single air bleed path system in the conventional carburetor will be inversely proportional to Rch 2 +R 0 . If the values of R 1 and R 2 are designed to be comparable to each other, so as for example to be equal, then in view of equation (*) above, and in view of the fact that in this case R 1 is twice as large as R 1 R 2 /(R 1 +R 2 ), the amount of bleed air supplied through said primary air bleed path system will be much smaller than that supplied through said single air bleed path system in the conventional carburetor, thereby avoiding to a certain extent the problem due to over lean air-fuel mixture supplied to the engine in such a transient period. In fact, if the air bleed system is so designed that the air flow resistance of said air bleed control valve is comparable with that of said primary and secondary air bleed path systems, so as for example to be equal, the ratio between the amount of bleed air supplied to the engine in said transient period by the carburetor, according to the present invention, and that supplied by the conventional carburetor becomes as much as 1.5 versus 2.
Further, according to another aspect of the present invention, these and other objects are more particularly and concretely accomplished by an air/fuel ratio control system of the sort described above, said sensor being an oxygen sensor which detects the concentration of oxygen in the exhaust gases within said exhaust system, and said electrical control unit producing such a valve control electrical signal, in response to said sensor electrical signal, as by supply of said bleed air to keep the air/fuel ratio of the air-fuel mixture supplied to said internal combustion engine by said carburetor substantially in a small range about the stoichiometric ratio.
Further, according to a first particular aspect of the present invention, these and other objects are more particularly and concretely accomplished by an air/fuel ratio control system of the sort described above, said carburetor further comprising a primary well within which fuel is maintained at a first predetermined fuel level, a secondary well within which fuel is maintained at a second predetermined fuel level, a primary air bleed tube protruding into said primary well below said first predetermined fuel level and formed with a plurality of air bleed holes below said first predetermined fuel level, and a secondary air bleed tube protruding into said secondary well below said second predetermined fuel level and formed with a plurality of air bleed holes below said second predetermined fuel level, a flow of basic primary bleed air being admitted into said primary air bleed tube, and a flow of basic secondary bleed air being admitted into said secondary air bleed tube, fuel-air mixture formed within said primary well being supplied to said primary main fuel supply nozzle so as to be sucked therefrom into said primary intake passage by the depression in said primary intake passage when air is flowing through said primary intake passage, and fuel-air mixture formed within said secondary well being supplied to said secondary main fuel nozzle so as to be sucked therefrom into said secondary intake passage by the depression in said secondary intake passage when air is flowing through said secondary intake passage; said primary air bleed path system supplying bleed air into fuel-air mixture formed within said primary well downstream of said primary well and upstream of said primary main fuel supply nozzle, and said secondary air bleed path system supplying bleed air into fuel-air mixture formed within said secondary well downstream of said secondary well and upstream of said secondary main fuel supply nozzle.
According to such a structure, the primary bleed air admitted via said primary air bleed path system is admitted to mix the the air-fuel mixture which has been formed by mixing the fuel within said primary well with the basic primary bleed air which has passed through said air bleed holes in said primary bleed air tube, before said air-fuel mixture passes out of said primary main fuel nozzle; and, when provided, the secondary bleed air admitted via said secondary air bleed path system is admitted to mix with the air-fuel mixture which has been formed by mixing the fuel within said secondary well with the basic secondary bleed air which has passed through said air bleed holes in said secondary bleed air tube, before said air-fuel mixture passes out of said secondary main fuel nozzle.
Further, according to another alternative particular aspect of the present invention, these and other objects are alternatively more particularly and concretely accomplished by an air/fuel ratio control system of the sort described above, said carburetor further comprising a primary well within which fuel is maintained at a first predetermined fuel level, a secondary well within which fuel is maintained at a second predetermined fuel level, a primary air bleed tube protruding into said primary well below said first predetermined fuel level and formed with a plurality of air bleed holes below said first predetermined fuel level, and a secondary air bleed tube protruding into said secondary well below said second predetermined fuel level and formed with a plurality of air bleed holes below said second predetermined fuel level, a flow of basic primary bleed air being admitted into said primary air bleed tube, and a flow of basic secondary bleed air being admitted into said secondary air bleed tube, fuel-air mixture formed within said primary well being supplied to said primary main fuel supply nozzle so as to be sucked therefrom into said primary intake passage by the depression in said primary intake passage when air is flowing through said primary intake passage, and fuel-air mixture formed within said secondary well being supplied to said secondary main fuel supply nozzle so as to be sucked therefrom into said secondary intake passage by the depression in said secondary intake passage when air is flowing through said secondary intake passage; said primary air bleed path system supplying bleed air into said primary air bleed tube to be added to said basic primary bleed air therein, and said secondary air bleed path system supplying bleed air into said secondary air bleed tube to be added to said basic secondary bleed air therein.
According to such a structure, the primary bleed air admitted via said primary air bleed path system is admitted to mix with said flow of basic primary bleed air, before said combined bleed air passes through said air bleed holes in said primary bleed air tube and mixes with the fuel within said primary well to form air-fuel mixture which passes out of said primary main fuel nozzle; and, when provided, the secondary bleed air admitted via said secondary air bleed path system is admitted to mix with said flow of basic secondary bleed air, before said combined bleed air passes through said air bleed holes in said secondary bleed air tube and mixes with the fuel within said secondary well to form air-fuel mixture which passes out of said secondary main fuel nozzle.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will now be shown and described with reference to several preferred embodiments thereof, and with reference to the illustrative drawings. It should be clearly understood, however, that the description of the embodiments, and the drawings, are all of them given purely for the purposes of explanation and exemplification only, and are none of them intended to be limitative of the scope of the present invention in any way, since the scope of the present invention is to be defined solely by the legitimate and proper scope of the appended claims. In the drawings:
FIG. 1 is a partly schematic side view, showing an internal combustion engine incorporating an exhaust system including a three way catalytic converter and a double barreled carburetor, which is equipped with an air/fuel ratio control system according to the present invention, this figure being applicable to both the first and the second preferred embodiments of the present invention;
FIG. 2 is a part sectional view of the above mentioned double barreled carburetor to which the first preferred embodiment of the air/fuel ratio control system according to the present invention is applied, and also shows in schematic view the constituent parts of said first preferred embodiment of the present invention; and
FIG. 3 is a part sectional view, similar to FIG. 2, of the double barreled carburetor to which the second preferred embodiment of the air/fuel ratio control system according to the present invention is applied, and also shows in schematic view the constituent parts of said second preferred embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will now be described with respect to two preferred embodiments thereof, and with respect to the accompanying drawings.
FIG. 1 is a partly schematic side view, which is applicable to both of the two preferred embodiments of the air/fuel ratio control system according to the present invention which will be described. An internal combustion engine 1 sucks in air through an air cleaner 2, and liquid fuel such as gasoline is mixed with this air in a carburetor 3, the air-fuel mixture thus produced being conducted through an intake manifold 4 and being sucked into and combusted in the combustion chambers of said internal combustion engine 1. These combustion chambers are not shown in the figures. The exhaust gases produced by combustion of this air-fuel mixture are vented from the internal combustion engine 1 into an exhaust manifold 5, and via an exhaust pipe 6 are conveyed to a three way catalytic converter 7, within which they are catalytically purified of various harmful exhaust components contained therein, such as HC, CO, and NOx, in a per se well known manner. From the three way catalytic converter 7 these purified exhaust gases are then vented through an exhaust pipe 8 to the atmosphere.
An oxygen sensor or O2 sensor 64 is mounted to the side of the exhaust pipe 5 so as to sense the concentration of oxygen in the exhaust gases which are being vented through the exhaust pipe 5, and an electrical sensor output signal produced by the oxygen sensor 64 and representative of said concentration is fed to an electrical control unit 65, which, based on said electrical sensor output signal, outputs a valve control electrical signal which is fed to two air bleed control valves 56 and 61 which will be more particularly described hereinafter. Via these air bleed control valves 56 and 61, via air bleed conduits 55 and 60, via a T junction 51, and via air bleed conduits 50, 52, and 53, bleed air is supplied from the atmosphere to various points within the carburetor 3, as will also be more particularly described hereinafter.
The general operation of this air/fuel ratio control system, including the operation of the electrical control unit 65, is as follows.
If the oxygen sensor 64 is detecting a surplus of oxygen in the exhaust gases which are being exhausted from the internal combustion engine 1 through the exhaust manifold 5, which indicates that the air/fuel ratio of the air-fuel mixture which is being produced by the carburetor 3 is substantially higher than the stoichiometric value, i.e. that this air-fuel mixture is over lean, then, based on the signal which the electrical control unit 65 receives from said O2 sensor 64, said electrical control unit 65 produces a valve control electrical signal which has the effect of increasing the flow resistance of the air bleed control valves 56 and 61, and thereby the amount of bleed air fed into the air-fuel mixture which is being produced by the carburetor 3 is diminished, thus decreasing the air/fuel ratio of the air-fuel mixture being produced by said carburetor 3, i.e. richening said air-fuel mixture.
On the other hand, if the oxygen sensor 64 is detecting no oxygen in the exhaust gases which are being exhausted from the internal combustion engine 1 through the exhaust manifold 5, which indicates that the air/fuel ratio of the air-fuel mixture which is being produced by the carburetor 3 is substantially lower than the stoichiometric value, i.e. that this air-fuel mixture is over rich, then, based on the signal which the electrical control unit 65 receives from said O2 sensor 64, said electrical control unit 65 produces a valve control electrical signal which has the effect of decreasing the air flow resistance of the air bleed valves 56 and 61, and thereby the amount of bleed air fed into the air-fuel mixture which is being produced by the carburetor 3 is increased, thus increasing the air/fuel ratio of the air-fuel mixture being produced by said carburetor 3, i.e. weakening said air-fuel mixture.
Various considerations arise with regard to the response time of this feedback control system, and the stability of its operation; but they are per se well known in the art, and not strictly relevant to the principles of the present invention, and will therefore not be further herein discussed. The present invention is applicable to any system of the general sort outlined herein above.
In relation to the operation of this feedback control system for bleed air amount, it will be understood by one skilled in the art that variation of the air flow within the carburetor 3, and/or variation of the amount of fuel which is being mixed into this air flowing through the carburetor 3 to produce air-fuel mixture, may be coped with in a feedback fashion by the air/fuel ratio control system comprising this electrical control unit 65, etc., provided that such variations are reasonably slow. On the other hand, if the variation in the air flow in the carburetor 3, or the variation in the amount of fuel being mixed in therewith by the carburetor 3, is rather quick, then, because of the time taken for air-fuel mixture to pass through the internal combustion engine 1 and for the exhaust gases resulting from the combustion of this air-fuel mixture to be exhausted into the exhaust pipe 5 so as to affect the oxygen sensor 64, and because also of the finite response time of the electrical control unit 65 and of the air bleed control valves 61 and 56, etc., then for a certain transient time the air/fuel ratio of the air-fuel mixture being conducted through the inlet manifold 4 into the combustion chambers of the internal combustion engine 1 will deviate from the stoichiometric value. If this deviation is too great and is maintained for too long a time, this will cause improper operation of the three way catalytic converter 7, and therefore undesirable pollutants such as HC, CO, or nitrogen oxides (depending upon whether the deviation from the stoichiometric condition of the exhaust gases has been in the direction of over rich or over lean air-fuel mixture) will be emitted in the exhaust gases expelled through the exhaust pipe 8 to the atmosphere, which is very undesirable, especially in view of the fact that the standards for quality control of such exhaust gases are becoming more and more severe nowadays. Accordingly, it is desirable that the rate of variation of the air flow through the carburetor 3, and the rate of variation of the amount of fuel being mixed into this air to form air-fuel mixture, should be minimized or kept reasonably low, or at least that this variation should not actually be discontinuous.
In FIG. 2, there is presented a sectional view of the carburetor 3, and also a schematic view of other parts of the first preferred embodiment of the air/fuel ratio control system according to the present invention. In FIG. 2, reference numerals which denote parts which correspond to parts shown in FIG. 1 are the same as the numerals used in FIG. 1.
The carburetor 3 is a double barreled carburetor, and in fact in this case is a down draft double barreled carburetor. In the carburetor 3 there are formed a primary intake passage 10 and a secondary intake passage 30.
In the primary intake passage 10 there is provided a primary large venturi 11, and in the secondary intake passage 30 there is provided a secondary large venturi 31. In the throat of the primary large venturi 11 there is provided a primary small venturi 12, and, similarly, in the throat of the secondary large venturi 31 there is provided a secondary small venturi 32. Downstream from the primary large venturi 11 in the primary intake passage 10 there is mounted a butterfly type primary throttle valve 13, and, similarly, downstream from the secondary large venturi 31 in the secondary intake passage 30 there is mounted a butterfly type secondary throttle valve 33. Further, upstream of the primary small venturi 12 in the primary intake passage 10 there is mounted a choke valve 14, which will not be further discussed herein, because it is not relevant to the present invention.
In a per se well known fashion, as the accelerator pedal (which is not shown) of the vehicle in which this system is incorporated is progressively depressed, the primary throttle valve 13 is progressively opened; and, again in a per se well known fashion, when the primary throttle valve 13 has opened to a certain predetermined amount, then the secondary throttle valve 33 commences to be opened, and, as the primary throttle valve 13 progressively opens beyond this predetermined amount, progressively the secondary throttle valve 33 is opened along therewith, provided that the rate of intake air flow is also greater than a certain predetermined amount.
Into the throat portion of the primary small venturi 12 there opens a primary main fuel supply nozzle 15, and, similarly, into the throat portion of the secondary small venturi 32 there opens a secondary main fuel supply nozzle 35. A common float chamber 16, which serves both the primary fuel supply system and also the secondary fuel supply system, is kept filled to a certain predetermined level with liquid fuel, which in the present case is gasoline, by a float and needle valve system of a conventional kind not fully shown in the drawings and not further discussed here. A primary main fuel supply passage 18 leads from a lower part of the float chamber 16 to a primary well 19, the flow rate of gasoline from the float chamber 16 into the end joining thereto of this primary main fuel supply passage 18 being regulated by a primary main fuel jet 17 fitted into said end of said primary fuel supply passage 18. Similarly, a secondary main fuel supply passage 38 leads from another lower part of the float chamber 16 to a secondary well 39, the flow rate of gasoline from the float chamber 16 into the end joining thereto of this secondary main fuel supply passage 38 being regulated by a secondary main fuel jet 37 fitted into said end of said secondary main fuel supply passage 38. The upper part of the primary well 19 is communicated to the primary main fuel supply nozzle 15, and, similarly, the upper part of the secondary well 39 is communicated to the secondary main fuel supply nozzle 35.
A primary air bleed tube 20 formed with a plurality of small primary air bleed holes 20' extends downwards into the primary well 19, and the upper end of this primary air bleed tube 20 is communicated, via a fixed metering primary air bleed jet 21, to the atmosphere. As can be seen in FIG. 2, these small primary air bleed holes 20' are arranged to be below the level of the surface of the liquid fuel within the primary well 19, when this fuel is in a state of static equilibrium with the fuel in the float chamber 16.
Similarly, a secondary air bleed tube 40 formed with a plurality of small secondary air bleed holes 40' extends downwards into the secondary well 39, and the upper end of this secondary air bleed tube 40 is communicated, via a fixed metering secondary air bleed jet 41, to the atmosphere. Similarly to the primary air bleed holes 20' in the primary fuel system, these small secondary air bleed holes 40' are arranged to be below the level of the surface of the liquid fuel within the secondary well 39, when this fuel is in a state of static equilibrium with the fuel in the float chamber 16.
Thus, during operation of the internal combustion engine 1, when air is flowing through the primary intake passage 10, depression in the primary small venturi 12 in this primary intake passage 10 in the vicinity of the primary main fuel supply nozzle 15 sucks liquid fuel out from the float chamber 16, through the primary main fuel jet 17 which meters its flow, along the primary main fuel supply passage 18, and into the primary well 19. Atmospheric air is also sucked in through the primary fixed air bleed jet 21 (which meters its flow) into the primary air bleed tube 20 and out through the plurality of primary air bleed holes 20' therein to be mixed with this liquid fuel present within the primary well 19, and this mixture of liquid gasoline together with bleed air is sucked along towards and out of the primary main fuel supply nozzle 15, so as to be ejected within the primary small venturi 12 and therein sprayed into and mixed with the air which is flowing through the primary intake passage 10. In an exactly similar fashion, when air is flowing through the secondary intake passage 30, depression in the secondary small venturi 32 in this secondary intake passage 30 in the vicinity of the secondary main fuel supply nozzle 35 sucks liquid fuel out of the float chamber 16, through the secondary main fuel jet 37 which meters its flow, along the secondary main fuel supply passage 38, and into the secondary well 39. Atmospheric air is also sucked in through the secondary fixed air bleed jet 41 (which meters its flow) into the secondary air bleed tube 40 and out through the plurality of secondary air bleed holes 40' therein to be mixed with this liquid fuel present within the secondary well 39, and this mixture of liquid gasoline together with bleed air is sucked along towards and out of the secondary main fuel supply nozzle 35, so as to be ejected within the secondary small venturi 32 and therein sprayed into and mixed with the air which is flowing through the secondary intake passage 30.
This system ensures that the amount of fuel ejected from the primary and secondary main fuel supply nozzles 15 and 35 is reduced, according to the amount of bleed air supplied thereinto, so that the air/fuel ratio of the air-fuel mixture passing into the inlet manifold 4 from the primary and secondary intake passages 10 and 30 is increased, i.e. this air-fuel mixture is made leaner. In fact, the air/fuel ratio of the air-fuel mixture thus produced is set to be still a somewhat richer air/fuel ratio than the stoichiometric value, so that the basic air-fuel mixture produced by the carburetor 3 in the fashion described above is still somewhat rich.
Within the primary intake passage 10 there is provided a primary slow fuel port 22, which opens to a point on the inner surface of the primary intake passage 10 which is upstream of the primary throttle valve 13 when the primary throttle valve 13 is in the substantially closed position as shown in FIG. 2, but which is downstream of the primary throttle valve 13 when the primary throttle valve 13 is opened by more than a very small amount. Similarly, within the secondary intake passage 30 there is provided a secondary slow fuel port 42, which opens to a point on the inner surface of the secondary intake passage 30 which is upstream of the secondary throttle valve 33 when the secondary throttle valve 33 is in the substantially closed position as shown in FIG. 2, but which is downstream of the secondary throttle valve 33 when the secondary throttle valve 33 is opened by more than a very small amount. Further, a primary idle port 23 is provided within the primary intake passage 10, and opens at a point on the surface thereof which is always downstream of the primary throttle valve 13. No idle port is provided within the secondary intake passage 30, for reasons which will be obvious to one skilled in the art.
A primary slow fuel passage 24 branches off from an intermediate point of the primary main fuel supply passage 18, and this primary slow fuel passage 24 supplies fuel to the primary slow fuel port 22 and also to the primary idle port 23. Similarly, a secondary slow fuel passage 44 branches off from an intermediate point of the secondary main fuel supply passage 38, and this secondary slow fuel passage 44 supplies fuel to the secondary slow fuel port 42. A fixed amount of bleed air is admitted to an intermediate part of the primary slow fuel passage 24 through a fixed primary slow air bleed jet 27, and, similarly, a fixed amount of bleed air is admitted to an intermediate part of the secondary slow fuel passage 44 through a fixed secondary slow air bleed jet 47. Further, the rate of ejection of fuel and bleed air mixture through the primary idle port 23 may be regulated by a manually settable idle adjuster screw 26 in a per se well known fashion.
These arrangements regarding the primary and secondary slow fuel passages 24 and 44, the primary and secondary slow ports 22 and 42, and the primary idle port 23, are not directly relevant to the gist of the present invention, and are only described here for the purposes of completeness of explanation.
There will now be described the arrangements for providing a variable amount of extra bleed air into the mixture, composed of fuel and the above described basic bleed air, which is being ejected from the primary main fuel supply nozzle 15 and from the secondary main fuel supply nozzle 35.
To the base end of the primary main fuel supply nozzle 15, close to where said nozzle 15 opens into the primary well 19, there opens the lower end of a primary extra air bleed passage 28. The other end of this primary extra air bleed passage 28 is connected to the lower end of an air bleed conduit 29, which projects upwards as seen in FIG. 2 out of the body of the carburetor 3. According to the present invention, similarly, to the base end of the secondary main fuel supply nozzle 35, close to where said nozzle 35 opens into the secondary well 39, there opens the lower end of a secondary extra air bleed passage 48. The other end of this secondary extra air bleed passage 48 is connected to the lower end of an air bleed conduit 49, which projects upwards as seen in FIG. 2 out of the body of the carburetor 3.
The end remote from the carburetor 3 of the primary air bleed conduit 29 is connected to one end of an air bleed conduit 50, already mentioned, and the end remote from the carburetor 3 of the air bleed conduit 49 is connected to one end of another air bleed conduit 52. The other end of the air bleed conduit 52 is connected to the outlet of a one way air valve 53. The inlet of the one way air valve 53 is connected to one end of an air bleed conduit 54. The other end of the air bleed conduit 50 and the other end of the air bleed conduit 54 are connected to the two outlets of a T junction or pipe branch 51, and the inlet of this T junction 51 is connected to one end of an air bleed conduit 55, the other end of which is connected to the outlet 57 of the above mentioned air bleed control valve 56.
The direction of flow available through the one way air valve 53, as intimated above, is such that bleed air can flow from the air bleed conduit 54 through the one way air valve 53 into the air bleed conduit 52, but cannot flow in the reverse direction from the air bleed conduit 52 through the one way air valve 53 into the air bleed conduit 54. The one way air valve 53 prevents air flowing from the secondary main fuel supply nozzle 35 to the primary air bleed path system when only the primary air bleed path system is operating.
Further, arrangements are provided for admitting a certain variable amount of extra bleed air into the liquid fuel which is being emitted from the primary slow fuel port 22 and/or from the primary idle port 23, which will now be described. A bleed air conduit 59 has its outer end projected from the outside of the carburetor 3, while its inner end extends into a well formed at an intermediate portion of the primary slow fuel passage 24, the base of the primary slow fuel port 22 also opening into this well. Thus, when bleed air is supplied to this bleed air conduit 59, it is mixed in to the mixture of liquid fuel flowing within the primary slow fuel passage 24 and the fixed amount of bleed air which has been mixed in therewith by passage thereof in through the fixed primary slow air bleed jet 27, said air-fuel mixture being supplied both to the primary slow fuel port 22 and to the primary idle port 23.
To the outside end of the air bleed conduit 59, i.e., to its end remote from the carburetor 3, there is connected one end of the above mentioned air bleed conduit 60, and the other end of this air bleed conduit 60 is connected to the outlet 62 of the above mentioned air bleed control valve 61.
The air flow passage provided by the air bleed conduit 50, the air bleed conduit 29, and the air bleed passage 28 connected in series forms a primary air bleed path system which has a certain first air flow resistance, while the air flow passage provided by the air bleed conduit 54, the one way air valve 53, the air bleed conduit 52, the air bleed conduit 49, and the air bleed passage 48 connected in series forms a secondary air bleed path system which has a certain second air flow resistance.
The air bleed control valve 56 and the air bleed control valve 61 are both of the same sort, which is a sort conventionally well known and used in the art. Each of these air bleed control valves 56 and 61 has an air inlet, these air inlets being denoted respectively by the reference numerals 58 and 63, which is open to the atmosphere, and an air outlet, denoted respectively by 57 and 62, at which a regulated amount of bleed air is provided. Each of these air bleed control valves 56 and 61, according to the value of an electrical signal which is supplied to an input terminal thereof, varies the resistance to air flow between its inlet 58 or 63 and its outlet 55 or 62 in a progressive fashion; that is, according to the value of the above mentioned valve control electrical signal, the air flow resistance of each of these bleed air control valves 56 and 61 can be varied relatively smoothly from an essentially infinite value, when no air bleed is provided by the valve and its inlet is shut off from its outlet, down to a certain basic or fully open value, through a range of values of air flow resistance. Such bleed air control valves are well known in the art, and, for example, include electric air control valves which comprise a valve element which responds to an electrical impulse provided to the input terminal of the value, and which may be of the linear motor type, the linear solenoid type, or the step motor type.
As has been outlined above, an oxygen sensor or O2 sensor 64 is fitted to the exhaust manifold 5. An output signal is produced by this oxygen sensor 64, and is representative of the concentration of oxygen in the exhaust gases in the exhaust pipe 5. The electrical control unit 65 receives this electrical sensor output signal, and, based thereupon, outputs the valve control electrical signal, which, in the shown first preferred embodiment of the present invention, is fed to both of the air bleed control valves 56 and 61, so as to cause them to regulate their air flow resistance and so as thereby to regulate the amount of bleed air which is admitted, respectively, into the air bleed conduits 55 and 60. In more detail, the electrical control unit 65 is so constituted that when it receives an electrical sensor output signal from the oxygen sensor 64 indicative of the presence of substantially no oxygen in the exhaust gases in the exhaust pipe 5, then said electrical control unit 85 generates such a valve control electrical signal as, when fed to the air bleed control valves 56 and 61, causes their opening amounts to increase, i.e. causes their flow resistances to decrease; and, conversely, when the electrical control unit 65 receives an electrical sensor output signal from the oxygen sensor 64 indicative of the presence of a substantial amount of oxygen in the exhaust gases in the exhaust pipe 5, then said electrical control unit 65 generates such a valve control electrical signal as, when fed to the air bleed control valves 56 and 61, causes their opening amounts to decrease i.e. causes their flow resistances to increase.
Thus, suppose that the internal combustion engine is operating steadily at a certain load level, with the primary throttle valve 13 open by a certain amount and possibly the secondary throttle valve 33 open by a certain amount. Now, in this state which for the moment should be assumed to be fairly steady, when the oxygen sensor 64 is not detecting the presence of substantially any oxygen in the exhaust gases of the internal combustion engine 1 in the exhaust pipe 5, which indicates that the air/fuel ratio of the air-fuel mixture being supplied to the engine by the carburetor 3 is substantially richer, i.e., smaller, than stoichiometric, then the electrical control unit 65, which is receiving an electrical sensor output signal representative of this state of affairs from the oxygen sensor 64, is outputting a valve control electrical signal to the air bleed control valves 56 and 61 which is causing their opening amounts to increase. By the increasing opening of the air bleed control valve 61, an increasing amount of bleed air is supplied into the fuel which is being ejected from the primary slow port 22 and/or from the primary idle port 23, if any such fuel is in fact being ejected; and by the increasing opening of the air bleed control valve 56 an increasing amount of bleed air is supplied into the fuel which is being ejected from the primary main fuel nozzle 15 due to the depression in the primary inlet passage 10 in the vicinity of the primary small venturi 12, and, in the case that the secondary throttle valve 33 is opened and significant depression exists in the secondary inlet passage 30 in the vicinity of the primary small venturi 32, an increasing amount of bleed air is supplied into the fuel which is being ejected from the primary main fuel nozzle 15 due to this depression in the primary inlet passage 10 in the vicinity of the primary small venturi 12. (On the other hand, if no significant depression exists in the secondary inlet passage 30 in the vicinity of the primary small venturi 32, the provision of the one way valve 53 prevents reverse flow of air at atmospheric pressure from the secondary main fuel nozzle 35, through the conduit 52, the one way valve 53, the conduit 54, and into the conduit 50 to be mixed in with the bleed air from the air bleed control valve 56 which is being supplied via the conduit 50 to the primary main fuel nozzle 15). Thus, the air/fuel ratio of the air-fuel mixture being supplied to the engine by the carburetor 3 is steadily increased, so as to bring it closer to stoichiometric.
On the other hand, if in this state which for the moment is assumed to be fairly steady the oxygen sensor 64 is detecting the presence of a substantial amount of oxygen in the exhaust gases of the internal combustion engine 1 in the exhaust pipe 5, which indicates that the air/fuel ratio of the air-fuel mixture being supplied to the engine by the carburetor 3 is substantially leaner, i.e. larger, than stoichiometric, then the electrical control unit 65, which is receiving an electrical sensor output signal representative of this state of affairs from the oxygen sensor 64, is outputting a valve control electrical signal to the air bleed control valves 56 and 61 which is causing their opening amounts to decrease. By the decreasing opening of the air bleed control valve 61, a decreasing amount of bleed air is supplied into the fuel which is being ejected from the primary slow port 22 and/or from the primary idle port 23, if any such fuel is in fact being ejected; and by the decreasing opening of the air bleed control valve 56 a decreasing amount of bleed air is supplied into the fuel which is being ejected from the primary main fuel nozzle 15 due to the depression in the primary inlet passage 10 in the vicinity of the primary small venturi 12, and, in the case that the secondary throttle valve 33 is opened and significant depression exists in the secondary inlet passage 30 in the vicinity of the primary small venturi 32, a decreasing amount of bleed air is supplied into the fuel which is being ejected from the primary main fuel nozzle 15 due to this depression in the primary inlet passage 10 in the vicinity of the primary small venturi 12. (Again, on the other hand, if no significant depression exists in the secondary input passage 30 in the vicinity of the primary small venturi 32, the provision of the one way valve 53 prevents reverse flow of air at atmospheric pressure from the secondary main fuel nozzle 35, through the conduit 52, the one way valve 53, the conduit 54, and into the conduit 50 to be mixed in with the bleed air from the air bleed control valve 56 which is being supplied via the conduit 50 to the primary main fuel nozzle 15). Thus, the air/fuel ratio of the air-fuel mixture being supplied to the engine by the carburetor 3 is steadily decreased, so as to bring it closer to stoichiometric.
Thus, by a feedback process of the sort outlined above, the air/fuel ratio of the air-fuel mixture being supplied to the engine by the carburetor 3 is kept more or less at the stoichiometric value, i.e. is kept within a fairly narrow range about the stoichiometric value, during steady state operation of the internal combustion engine 1 at a definite load value, i.e. a definite throttle opening. In this case, as so far described, the effect of the operation of the air/fuel ratio control system according to this first preferred embodiment of the present invention is substantially the same as the effect of a conventional or prior art system; although in the present system the bleed air regulated by the bleed air control valve 56 is in fact injected into the carburetor both through the primary main fuel nozzle 12 and also through the secondary main fuel nozzle 32 (in the case that the secondary throttle valve 33 is significantly open) as bleed air, this produces no particular novel effects in the steady state operational condition.
Suppose now however that the load on the internal combustion engine 1, i.e. the throttle opening thereof, varies. The operation of the air/fuel ratio control system according to this first preferred embodiment of the present invention, and its superiority over the prior art conventional systems, will now be described with reference to the case that: first the internal combustion engine 1 is operating at high load, with both the primary throttle valve 13 and also the secondary throttle valve 33 opened; and then the load is quickly or abruptly diminished, so that the secondary throttle valve 33 is suddenly completely closed.
When the internal combustion engine 1 is operating at high load, with both the primary throttle valve 13 and also the secondary throttle valve 33 opened, bleed air will be supplied through the bleed air control valve 56, the conduit 55, the T junction 51, and the conduit 50 to the primary air bleed conduit 29 to be supplied into the primary extra air bleed passage 28 to mix with the air-fuel mixture being ejected from the primary main fuel nozzle 15 on the one hand, while on the other hand bleed air will pass through the conduit 54 and the one way air valve 53 and the conduit 52 to the secondary air bleed conduit 49 to be supplied into the secondary extra air bleed passage 48 to mix with the air-fuel mixture being ejected from the secondary main fuel nozzle 35. In this state, by the feedback action explained above the opening of the air bleed control valve 56 will be brought to such an opening as to provide such an amount of bleed air as to make the air/fuel ratio of the air-fuel mixture being supplied by the carburetor 3 substantially the stoichiometric value.
At this time--in contradistinction to the operation of the conventional prior art type system discussed above in the section of this specification entitled "BACKGROUND OF THE INVENTION" in which the additional bleed air supplied through the bleed air control valve is added only to the air-fuel mixture which is being discharged through the primary main fuel nozzle into the primary air intake passage and not to the air-fuel mixture which is being discharged through the secondary main fuel nozzle into the secondary air intake passage and in which prior art system therefore in such high load operational conditions as these the air/fuel ratio of the air-fuel mixture being generated in the primary air intake passage is substantially leaner than stoichiometric while the air/fuel ratio of the air-fuel mixture being generated in the secondary air intake passage is substantially richer than stoichiometric--because according to the essence of the present invention the additional bleed air supplied through the bleed air control valve is added both to the air-fuel mixture which is being discharged through the primary main fuel nozzle into the primary air intake passage and also to the air-fuel mixture which is being discharged through the secondary main fuel nozzle into the secondary air intake passage, the air/fuel ratio of the air-fuel mixture being generated in the primary air intake passage is quite close to stoichiometric while the air/fuel ratio of the air-fuel mixture being generated in the secondary air intake passage is also quite close to stoichiometric.
Suppose now that, from the operational condition the load on the internal combustion engine 1 is abruptly decreased, so that the secondary throttle valve 33 is now completely closed. At this time the flow of air through the secondary air intake passage 30 will abruptly cease, and thus the depression within the secondary air intake passage 30 in the vicinity of the secondary small venturi 35 will abruptly disappear, thus causing the ceasing of the sucking out of fuel out of the secondary main fuel nozzle 35 and also the sucking in of bleed air to be mixed in with this fuel, both main bleed air through the secondary fixed air bleed jet 41 and also additional bleed air from the bleed air control valve 56 through the conduit 55, the T junction 51, the conduit 54, the one way air valve 53 in the direction of flow allowed by it, the conduit 52, and the secondary air bleed conduit 49 and the secondary extra air bleed passage 48. In the same way as detailed above, therefore, based upon the signal from the oxygen sensor 64, the electrical control unit 65 will generate such a control signal for the bleed air control valves 56 and 61 as to control them to provide a proper amount of bleed air in this new operational condition to bring the air/fuel ratio of the air-fuel mixture generated by the carburetor 3 as a whole to substantially the stoichiometric one.
However, the closing of the bleed air control valves 56 and 61 to their new lesser opening amounts, although quite quick, is by no means instantaneous as described above. However, in the present invention, because according to the essence of the present invention the additional bleed air supplied through the bleed air control valve when both the primary throttle valve and also the secondary throttle valve were open was added both to the air-fuel mixture which was being discharged through the primary main fuel nozzle into the primary air intake passage and also to the air-fuel mixture which was being discharged through the secondary main fuel nozzle into the secondary air intake passage, and therefore as detailed above the air/fuel ratio of the air-fuel mixture being generated in the primary air intake passage was quite close to stoichiometric while the air/fuel ratio of the air-fuel mixture being generated in the secondary air intake passage was also also quite close to stoichiometric, and further the air flow resistance of the primary air bleed path system and the secondary air bleed path system can each be increased as compared with the case of the conventional single air bleed path system, for the short transient time after the quick closing of the secondary throttle valve until the bleed air control valves 56 and 61 have reached their proper new opening amounts, the deviation of the air/fuel ratio of the air-fuel mixture supplied only through the primary fuel supply system from that of the air-fuel mixture which was previously being generated in the primary and secondary air intake passages is quite small. Thus it is avoided, in the operation of the present invention, that when the secondary throttle valve 33 of the carburetor 3 is quickly completely closed the exhaust gases of the engine should deviate from the stoichiometric condition toward the lean side by a substantial amount for a certain transient time; in other words, it is avoided that for such a transient time the functioning of the three way catalytic converter 7 for purifying the exhaust gases passing therethrough of nitrogen oxides or NOx by a reducing reaction should be significantly interrupted.
In FIG. 3, there is presented a sectional view of the carburetor 3, and also a schematic view of other parts of, a second preferred embodiment of the air/fuel ratio control system according to the present invention, in a fashion similar to FIG. 2. In FIG. 3, parts of the second preferred embodiment shown, which correspond to parts of the first preferred embodiment shown in FIG. 2, and which have the same functions, are designated by the same reference numerals and symbols as in that figure.
In this second preferred embodiment, the only differences are that the bleed air which is being supplied via the bleed air control valve 56 to the primary fuel system of the carburetor 3 via the the primary air bleed conduit 29 to be supplied into the primary extra air bleed passage 28 is not mixed directly with the air-fuel mixture which is being ejected through the primary main fuel nozzle 15, just before it is so ejected, but is instead added to the basic bleed air which has passed through the the primary fixed air bleed jet 21 (which meters its flow) into the primary air bleed tube 20, so as to pass out through the plurality of primary air bleed holes 20' therein to be mixed with the liquid fuel present within the primary well 19, so that this fuel mixed with both the basic bleed air and also the additional bleed air supplied through the bleed air control valve 56 is sucked along towards and out of the primary main fuel supply nozzle 15 to be ejected within the primary small venturi 12 and sprayed into and mixed with the air which is flowing through the primary intake passage 10, and similarly the bleed air which is being supplied via the bleed air control valve 56 to the secondary fuel system of the carburetor 3 via the the secondary air bleed conduit 49 to be supplied into the secondary extra air bleed passage 48 is not mixed directly with the air-fuel mixture which is being ejected through the secondary main fuel nozzle 35, just before it is so ejected, but is instead added to the basic bleed air which has passed through the secondary fixed air bleed jet 41 (which meters its flow) into the secondary air bleed tube 40, so as to pass out through the plurality of secondary air bleed holes 40' therein to be mixed with the liquid fuel present within the secondary well 39, so that this fuel mixed with both the basic bleed air and also the additional bleed air supplied through the bleed air control valve 56 is sucking along towards and out of the secondary main fuel supply nozzle 35 to be ejected within the secondary small venturi 32 and sprayed into and mixed with the air which is flowing through the secondary intake passage 20. It will be readily apparent to one skilled in the art, based upon the foregoing disclosure, that the operation of this second preferred embodiment of the air/fuel ratio control system according to the present invention is almost the same as that of the first preferred embodiment, mutatis mutandis, although the place of injection of the bleed air into the primary and secondary fuel systems of the carburetor 3 affects the air flow resistance of the primary and secondary air bleed path systems; what is important for the essence of the present invention is that this bleed air should be supplied both to the primary fuel system of the carburetor 3 and also to the secondary fuel system thereof, from the one bleed air control valve 56, with the interposition of the one way air valve 53 in the conduit leading to the secondary fuel system. Accordingly, further description of the operation of this second preferred embodiment of the air/fuel ratio control system according to the present invention will be foregone here, in the interests of avoiding redundancy of description.
Although the present invention has been shown and described with reference to several preferred embodiments thereof, and in terms of the illustrative drawings, it should not be considered as limited thereby. Various possible modifications, omissions, and alterations could be conceived of by one skilled in the art to the form and the content of any particular embodiment, without departing from the scope of the present invention. Therefore it is desired that the scope of the present invention, and of the protection sought to be granted by Letters Patent, should be defined not by any of the perhaps purely fortuitous details of the shown embodiments, or of the drawings, but solely by the scope of the appended claims, which follow.
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An engine includes a double barreled carburetor. A sensor mounted to the exhaust system detects the concentration of a component in the exhaust. A control unit, based on a signal from the sensor, dispatches a control signal to an air bleed control valve to vary its resistance. Primary and secondary path systems lead from the outlet of the air bleed control valve and respectively supply primary bleed air into the fuel which is being supplied into the primary barrel of the carburetor and secondary bleed air into the fuel which is being supplied into the secondary barrel of the carburetor. A one way valve is fitted in the secondary path system so as to allow air flow only towards the secondary barrel, and not away therefrom. Thus, when both barrels are opened, bleed air is sucked in to the primary barrel through the primary path system, and also bleed air is sucked in to the secondary barrel through the secondary path system past the one way valve; but, when only the primary barrel is opened, bleed air is sucked in to the primary barrel through the primary path system, but no bleed air is sucked in to the secondary barrel through the secondary path system, and the one way valve prevents reverse flow of air from the secondary barrel through the secondary path system and thencefrom into the primary path system towards the primary barrel.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of the US national stage designation of International application PCT/FR01/01179 filed Apr. 17, 2001, the entire content of which is expressly incorporated herein by reference thereto.
BACKGROUND ART
The invention relates to cutting at least one thin layer from a substrate or ingot, in particular of semiconductor material(s), for making an electronic, optoelectronic or optical component or sensor.
In numerous applications associated with the fields of microelectronics, optoelectronics, and sensors, the technological operation of transferring a layer of one substrate onto another represents a key operation that enables numerous materials structures or specific components to be fabricated. The layer for transfer may or may not include components that are complete or in a partial state of completion.
One example of such applications is in making silicon on insulator (SOI) substrates. Typically, the insulator used is SiO 2 of amorphous structure on which it is not possible to deposit silicon of monocrystalline quality. One category of techniques for making such structures relies on molecular adhesion techniques referred to as “wafer bonding”. These techniques are known to the person skilled in the art and in particular are described in the text “Semiconductor Wafer Bonding Science and Technology” by Q. Y. Tong and U. Gösele, a Wiley Interscience Publication, Johnson Wiley & Sons. Inc. As described in that text, using such techniques, two substrates (generally silicon substrates) are assembled together, one that is used to form the SOI layer (the “source” substrate) that is to be transferred onto the other substrate. This other substrate thus becomes the new “support” substrate that supports the SOI layer. A layer of insulation, typically of SiO 2 is previously formed on at least one of the faces of the substrates prior to assembly, thus obtaining a buried insulator situated beneath the SOI layer.
Certain variants are known as “bonded SOI” (BSOI) or indeed “bond etch back SOI” (BESOI). In addition to molecular adhesion, these variants rely on physically removing the source substrate either by techniques of the polishing or mechanical lapping type and/or by techniques of the chemical etching type. Other variants rely on splitting along a zone of weakness in addition to molecular adhesion on separation. These methods are described in U.S. Pat. No. 5,374,564 (or EP-A-0 533 551) and U.S. Pat. No. 6,020,252 (or EP-A-0 807 970) where splitting occurs along a weakened zone of implanted ions, or in European patent application 0 925 888, where splitting occurs through a buried layer that has been made porous.
Those layer transfer techniques present are of a generic nature since they enable structures to be made that combine various types of material with one another, and specifically that they enable structures to be obtained that are not possible to make otherwise, and in particular by deposition. Examples are monocrystalline silicon substrates on quartz, AsGa substrates on silicon, and the like.
The advantage of the methods that split along a buried fragile layer is that it is possible to make layers based on crystalline silicon (or on SiC, InP, AsGa, LinbO 3 , LiTaO 3 , and the like) in a range of thicknesses that extends from a few tens of angstroms (Å) to a few micrometers (μm), with very good uniformity. Even greater thicknesses are possible. other examples of applications in which layer transfer techniques can provide a suitable solution for integrating components or layers on a support that would otherwise be unsuitable for receiving such components or layers. These layer transfer techniques are also very useful when it is desired to isolate a fine layer, with or without components, from its initial substrate, e.g., by separating or eliminating the substrate.
By way of example, more and more components are expected to be integrated on supports that are different from those which enabled them to be made. By way of example, mention can in addition to making substrates, there are numerous be made of components on substrates made of plastics or on substrates that are flexible. The term “components” is used herein to mean any microelectronic device, optoelectronic device, or sensor device (e.g. a chemical, mechanical, thermal, biological, or biochemical sensor device) that is fully or partially “processed”, i.e. that has been made in full or in part. In order to integrate such components on flexible supports that are otherwise incompatible with such components, it is possible to use a layer transfer method which is performed after the components have been made on a substrate which is compatible with them.
Still in the same spirit, turning a fine layer over while transferring it to another support provides engineers with a degree of freedom that is very useful for designing structures that would otherwise be impossible. Taking and turning over such thin films make it possible, for example, to make so-called “buried” structures such as buried capacitors for dynamic random access memories (DRAMs) where, contrary to the usual case, the capacitors are made first and then transferred onto another silicon substrate, after which the remainder of the circuits are fabricated on the new substrate. Another example lies in the manufactures of double gate transistors. The first gate of a CMOS transistor is made using conventional technology on one substrate, and it is then turned over and transferred onto a second substrate where the second gate of the transistor is made and the transistor is finished, thus leaving the first gate buried within the structure (see for example K. Suzuki, T. Tanaka, Y. Tosaka, H. Horie, and T. Sugii, “High speed and low power n+-p+ double gate SOI CMOS”, IEICE Trans. Electron., Vol. E78-C, 1995, pp. 360-367).
An identical situation is to be found for example in the field of applications associated with telecommunications and microwaves. Under such circumstances, it is preferable for components finally to be integrated on a support presenting high resistivity, typically several kilo ohm-centimeters (kΩ.cm) at least. However a highly resistive substrate is not necessarily available at the same cost and quality as the standard substrates that are usually used. With silicon, silicon wafers having a diameter of 200 millimeters (mm) and wafers having a diameter of 300 mm are available at standard resistivity, whereas for resistivities greater than 1 kΩ.cm availability is quite inadequate at 200 mm and non-existent at 300 mm. One solution consists in making the components on standard substrates and then in transferring them during the final stages to a fine layer containing components on an insulating substrate of glass, quartz, sapphire, or the like.
From a technical point of view, these transfer operations have the major advantage of de-correlating the properties of the layer in which the components are made from those of the final support layer, and consequently they are advantageous in many other circumstances.
Relating more specifically to layer transfer techniques based on the splitting (i.e., breaking or separating) along a zone of weakness (“weakness” to be understood broadly and from a mechanical point of view) or a zone predefined to originate separation selectively (e.g., separation by chemical etching), several techniques are known concerning the step or combination that gives rise to the cut.
For example, certain combinations are based more specifically on mechanical separation (e.g., the high pressure water jet disclosed in EP 0 925 888). Certain techniques based on the so-called “lift-off” principle also enable a thin layer to be separated from the remainder of the initial support, without necessarily consuming it. Those methods generally make use of chemical etching that acts selectively on a buried intermediate layer, optionally associated with the application of mechanical forces. That type of method is in widespread use for transferring III-V elements on to various types of support (see C. Camperi et al. IEEE Transactions and Photonics Technology, Vol. 3, 12 (1991) 1123).
As another example, EP 0 925 888 describes slitting by means of a fracture along a buried layer that is made porous by mechanical means represented by a jet of water under pressure applied in the vicinity of the zone to be cut. A jet of compressed air can also be used as described in French patent application FR 2 796 491, or it is also possible to exert traction as disclosed in PCT published application WO 00/26000. It can also be appropriate to insert a blade.
Other examples rely on a zone of weakness obtained by implantation. A cut can be obtained along this zone of weakness, optionally by combining said implantation with the specific means for applying mechanical forces as mentioned above (or other such means) and/or chemical etching and/or heat treatments, etc. A few examples of such techniques are to be found in documents U.S. Pat. No. 5,374,564 (or EP-A-0 533 551) and U.S. Pat. No. 6,020,252 (or EP-A-0 807 970), and PCT published application WO 00/61841.
Numerous means can be adopted to trigger or assist splitting along a zone of weakness. U.S. Pat. Nos. 6,020,252 and 6,013,563 and European patent applications 0 961 312 and 1 014 452 provide more detailed explanations of, for example, mechanical forces in tension, in shear, in twisting, heat treatments using a wide variety of hot or cold sources of heat (conventional ovens, light means, lasers, electromagnetic fields, electron beams, cryogenic fluids, etc.), laser ablation of an intermediate layer, and the like.
The layer transfer techniques mentioned in the introduction nevertheless present certain specific drawbacks.
Techniques based on thinning down (mechanically, chemically, etc.) suffer from the drawback of consuming and sacrificing a substrate, which is inefficient from an economic standpoint. Such thinning techniques are also often quite difficult and expensive to implement.
Combinations based on applying external mechanical stresses (shear, twisting, bending, tension, and the like) suffer from the drawback of generally requiring adhesion (molecular or otherwise) that is sufficiently strong to avoid breaking under the stress needed for rupturing the weak zone. A method for obtaining such adhesion is not always available in certain manufacturing methods or applications which are subject to very severe specifications (e.g., where it is impossible to heat, impossible to use specific solvents or other chemicals, impossible to apply traction to the structure because of the risk of destroying sensitive components, etc.).
In certain applications, techniques based on annealing and other heat treatments come up against incompatibility with the step of raising temperature, e.g., the temperature of the final support on which the layer is to be integrated. For example, the new support may not be capable of withstanding the temperatures required. This generally applies to plastic materials. By way of another example, the incompatibility can stem from the combination of materials, in particular because they have too great a difference in thermal expansion coefficients which would cause an assembly that is not sufficiently uniform to break during a temperature rise. This would apply for example to a structure that combines silicon and quartz.
Techniques based on chemical etching are aggressive and this can make them incompatible with the final support on which the layer for transfer is to be integrated, or with components that might already be present on that layer.
Among other combinations, U.S. Pat. No. 6,013,563 and European patent application 1 014 452 describe or mention techniques based on applying beams of light and/or electrons. U.S. Pat. No. 6,013,563 refers to applying a beam of photons and/or electrons in order to heat the structure, while EP 1 014 452 describes a method in which an arbitrary source of photons (X rays, UV light, visible light, infrared light, microwaves, lasers, etc.) is suitable for giving rise to separation. The implementation described when using a laser, for example, refers to laser ablation of the intermediate layer which leads the authors to prefer using laser pulses of relatively high power (“preferably for energy densities lying in the range 100 millijoules per square centimeter (mJ/cm 3 ) and 500 mj/cm 3 ”) and of relatively long duration (“preferably for durations lying in the range 1 nanosecond (ns) to 1000 ns, and especially for durations lying in the range 10 ns to 100 ns”). The authors also state that that method of implementation requiring relatively large amounts of energy to be delivered in order to operate suffers from the drawback of possibly damaging the layer that is to be transferred.
Thus there is a need for further manufacturing processes that do not possess the disadvantages of the prior art.
SUMMARY OF THE INVENTION
The present invention provides a new method of cutting a semiconductor material along a zone of weakness which does not rely on raising temperature, chemical etching or decomposing the layer of weakness (whether by ablation or otherwise). In this method, a layer of weakness is cut by injecting a pulse of energy into the substrate so as to generate a sound wave of amplitude suitable for causing cleavage to take place in the layer of weakness.
The invention specifically relates to a method of cutting at least one thin layer from a substrate or ingot forming element for an electronic, optoelectronic or optical component or sensor. This method comprises forming a weakened zone in the substrate or ingot forming element, wherein the weakened zone has a thickness that corresponds to that of the layer that is to be removed; and directing a pulse of energy into the substrate or forming element wherein the pulse has a duration shorter than or of the same order as that needed by a sound wave to pass through the thickness of the weakened zone. The energy of the pulse is sufficient to cause cleavage to take place in the weakened zone as the energy of the pulse is absorbed therein.
In this method, the weakened zone can be a porous zone, in particular, one formed by deposition or by implantation. When implantation is used, the implantation is of phosphorus, arsenic, protons, or rare gas ions. Also, the substrate or ingot forming element advantageously comprises semiconductor material(s), LiNbO 3 , LiTaO 3 , or a composite material thereof. Especially preferred are Silicon, SiC, GaAs, InP, GaN, SiGe, Ge, LiNbO 3 , LiTaO 3 , or a composite material thereof.
After the weakened zone forming step, the substrate or ingot forming element is generally bonded onto a support to form a block. When this is done, the energy pulse is directed into the block. The block can be formed by bonding the substrate or ingot forming element onto the support by molecular adhesion bonding or by adhesive bonding. If desired, the block can include a layer of SiO 2 , Si 3 N 4 , or a combination thereof.
The energy pulse is preferably generated by a laser beam, although it also can be a beam of electrons. The energy pulse is of short duration so as to not cause heating of the block. Generally, a duration of less than 1 ns is used. The energy pulse may be a single pulse or repeated multiple times, as necessary to cause cutting of the layer.
In one embodiment, the substrate or ingot forming element has a polished face and the energy pulse is directed through that face and into the substrate or ingot forming element. When implantation is used to provide a weakened zone, the energy pulse can be directed into the substrate or ingot forming element through the same face as the implanted ions, or through a second face that is on an opposite side of the substrate or ingot forming element.
In a preferred embodiment, the energy pulse is directed to be selectively absorbed directly on the weakened zone. The substrate or ingot forming element can be doped so that the energy pulse is selectively absorbed in the weakened zone. If so, the doping preferably includes ionically implanting phosphorus or arsenic into the substrate or ingot forming element. The selective absorption can be performed in a metal layer, or within a deposited layer. Typically, the selective absorption is obtained within a layer whose properties have been modified by implantation.
The energy pulse may be directed onto the substrate or ingot forming element after all or part of a component of an electronic, optoelectronic or optical component or sensor has been made.
In this regard, the invention also relates to a method of making an electronic or optoelectronic or optical component or sensor which includes a method of cutting at least one thin layer from a substrate or ingot forming element according to the methods disclosed herein.
The invention also relates to an apparatus for carrying out these methods. This apparatus comprises means for directing a pulse of energy into the substrate or forming element wherein the pulse has a duration shorter than or of the same order as that needed by a sound wave to pass through the thickness of the weakened zone, and the energy of the pulse is sufficient to cause cleavage to take place in the weakened zone as the energy of the pulse is absorbed therein.
The energy pulse directing means preferably comprises a YAG or a neodymium-doped glass laser suitable for delivering pulses that have a duration of less than 1 ns. It may comprise a laser or a sheet of solid lasers, or a pulsed diode type pulse accelerator for delivering a beam of electrons that have a duration of less than 1 ns.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
The characteristics and advantages of the invention appear better from the following description referring to the accompanying figures in which:
FIGS. 1 a and 1 b are cross-sectional views taken through the set of semiconductor and insulating substrates after implantation ( FIG. 1 a ) and bonding ( FIG. 1 b );
FIGS. 2 a and 2 b are graphs showing the relationship for energy deposited in the material when the energy is deposited with a laser;
FIG. 3 is a graph that shows a sound wave at a given instant in the form of a curve P(x);
FIG. 4 is a graph that shows the sound wave behind a break in material in the form of the relationship P(x);
FIG. 5 illustrates an apparatus for depositing energy by laser pulse; and
FIG. 6 illustrates an apparatus for depositing energy when using an electron beam to heat the surface layer of a semiconductor substrate.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In a preferred first implementation of the invention, the procedure is as follows. The starting material is a semiconductor wafer, e.g. of silicon 2 (see FIG. 1 ) having a thickness of about 500 μm, which is polished on one of its faces 1 . Protons are implanted in its face at an energy such that their penetration depth into the semiconductor is a little greater than the thickness λ of the thin layer of semiconductor that is to be made. For example, to make a layer that is about 1 μm thick, protons are used at an energy of about 150 kilo-electon volts (keV).
Thereafter, an insulating substrate 4 is prepared, and in the example shown in FIG. 1 this is a substrate of silicon covered in a layer of SiO 2 having a typical thickness of a few tenths of a micrometer.
Thereafter, the substrates ( 4 and 2 ) are bonded together by molecular adhesion using a method that is now well known (see for example the text “Semiconductor wafer bonding Science and Technology” by Q. Y. Tong and U. Gösele, a Wiley Interscience Publication, Johnson Wiley & Sons. Inc.).
This produces the block shown in FIG. 1 b . This block is then impulse heated from the free surface of the semiconductor wafer 2 , i.e., the face 13 shown in FIG. 1 b . The purpose of the heating is to raise the pressure in the thickness ε 0 affected by the heating, with this being necessary in order to generate the sound wave that is to be used for breaking the implanted layer 7 that is weakened by implantation or by any other means. To heat the layer of thickness ε 0 beneath the surface 13 , it is necessary to implement or come close to implementing “constant volume heating” conditions. Heating causes expansion, but this can occur only in the form of a sound wave propagating at the speed of sound. If the heating is performed at a time t that is shorter than the time taken by the sound wave to pass through half the thickness of the heated layer (of thickness equal to ε 0 ), it will readily be understood that the center of this layer will not be able to expand throughout the duration of the heating. Heating is thus performed at “constant volume”, providing the following relationship is complied with, where C is the speed of sound:
t < ɛ 0 2 C
The orders of magnitude implied by this relationship are dominated by the need to implement a sound wave that is very short in three-dimensional space.
Specifically, it is deemed that this is satisfied when the duration of the energy pulse is less than or of the same order as the duration needed by a sound wave to pass through the thickness of the zone that absorbs the energy of the pulse. This pulse has the requisite energy to cause cleavage to take place in the weakened zone.
In order to ensure that the rupture mechanism is effective, it is necessary for ε 0 to be of the same order of magnitude as the thickness λ of the layer that is to be detached, which is of micrometer order. It is also known that in a semiconductor, e.g., silicon, the speed of sound is about 2×10 3 meters per second (m.s −1 ). The above relationship thus indicates that the duration of the pulse must be of the same order as or shorter than 1 ns, and preferably less than 0.5 ns, which is extremely brief but which can be achieved using special lasers or electron beams.
Once the above conditions are satisfied, the amplitude ΔP of the sound wave in compression or in expansion can be expressed by the Grüneisen relation:
Δ P = 1 2 Γ · ρ · ⅆ E ⅆ m
where:
Γ is the Grüneisen constant which for silicon is about 1.5; ρ is the density of the medium and is about 2.5×10 3 (S.I. units);
ⅆ E ⅆ m
is the variation in the specific internal energy of the medium. It is equal to the impulse heating per unit mass.
By way of example, it is assumed that the impulse heating gives rise to a temperature rise Δθ=75° C. in silicon having specific heat of 0.75 joules per gram, which gives:
ⅆ E ⅆ m = 5.62 × 10 4 ( S . I . units ) .
Inserting these values into the above equation, it is found that a typical pressure is 105 megapascals (MPa), or in other words 1.05 kilobars (kbar). It should be observed that this wave amplitude, when implemented in the form of expansion, is of the same order of magnitude as the cohesion strength of the material, and that it is therefore designed to break the layer that is weakened by ion implantation. Finally, it should be observed that such a high pressure is obtained merely by a modest temperature rise of 75° C. at the point where the energy is deposited, and that as soon as this energy disperses into the thickness of the substrate, the temperature rise becomes less than 1° C. It is thus genuinely possible to speak of a “cold” method of delamination, i.e., one that does not cause any appreciable heating of or damage to the material.
The sound waveform depends on how the deposited energy is distributed in the material. If it were possible to deposit the energy in zero time and if its distribution ε(x) as a function of depth x in the semiconductor ( 2 ) were of exponential appearance as shown diagrammatically in FIG. 2 a , then at the instant the pressure would be P(x) as represented by the curve shown in FIG. 2 b . In reality, the distribution Po(x) is deformed by the prorogation of expansion throughout the duration of deposition, and is never instantaneous.
This initial pressure splits into two waves, one going rearwards (in the increasing x direction) and the other going in the opposite direction, reflecting on the free face, and then also travelling rearwards, but this time in the form of an expansion wave. FIG. 3 shows the complete wave at a given instant during its propagation through wafer 2 . It will be observed that the total impulse, i.e., the area beneath the curve, is zero, which is necessary since the laser or electron beam responsible for the heating is of quasi-zero impulse. When the expansion wave reaches the implanted layer whose breaking stress is assumed to be T, then the wave as transmitted downstream is truncated, as shown in FIG. 4 . Thus, the impulse received by layer 2 and by its support 4 is not zero, causing the mass to be ejected at low speed.
There follows an examination of how the face 13 is impulse heated. It is shown above that the heated thickness should be about 1 μm, corresponding to a mass of material of about 2.5×10 −4 grams per square centimeter (g/cm 2 ). Thus, in order to achieve the above-mentioned impulse temperature rise of 75° C., it is necessary for the energy density of the beam to be about 1.87×10 −4 J/cm 2 . This ideal energy is very weak. In order to separate a layer from a wafer of 300 mm diameter, it would suffice for the laser pulse or electron beam to have energy of 0.13 J.
In reality, it is necessary to use much higher energy because of the expansion which occurs while energy is being deposited and also because absorption does not take place in ideal manner, i.e., it includes a distribution tail which is ineffective in raising pressure. In practice, the energy needed to separate a wafer over 300 mm diameter is about 13 joules.
In order to deposit the required energy in the surface 13 , it is possible either to use a very short pulse laser such as a yttrium aluminum garnet (YAG) laser, for example, using one or two stages of amplification and a Q-switched pilot with wavefront steeping by saturatable plates so as to achieve pulses of 0.1 ns to 1 ns duration. For higher energies per pulse, the final stages of amplification may be made of neodymium glass. A setup of the type shown in FIG. 5 is then obtained. A system of lenses L 1 , L 2 serves to apodize and expand the beam 9 so that the energy density is completely uniform over the entire surface 13 whose diameter can be as great as 300 mm using present-day technology. Once the apparatus has been set up, the laser beam having a wavelength close to 1.06 μm must be coupled with the semiconductor constituting the substrate 2 . When this semiconductor is made of silicon, if the 1.06 μm beam were to be used directly, then absorption would take place over a mean thickness of about 100 μm, which is much too great. In order to reduce the thickness of the energy deposition, it is necessary to increase the absorption of the medium 2 . This can be done by:
1) doubling, tripling, quadrupling the frequency of the laser beam using the now well known techniques based on non-linear effect plates;
2) surface doping, e.g. by ionically implanting phosphorus or arsenic in order to reduce resistivity and thus increase absorption of the material at 1 μm wavelength;
3) depositing a thin absorbent layer on the face 13 , e.g. a metal layer having at thickness of 1 μm.
To deposit the energy, it is also possible to use a pulsed electron beam ( 10 , see FIG. 6 ) obtained using a pulse diode 12 . To ensure that penetration in layer 2 is on the order of 1 μm, the energy of the electrons needs to be limited to about 30 keV. For a surface of 300 mm diameter, in order to deposit energy of about 3 joules, and taking account of the better absorption by layer 2 , the current delivered to the diode should be 150 kiloamps (kA), which is easily achievable.
In another preferred implementation of the invention, given by way of non-limiting indication, energy is deposited by means of a 1.06 μm laser beam as described above directly into the implanted layer 7 where it is desired to cause splitting or fracture. The description relates to the case where the semiconductor 2 is constituted by silicon. Given that silicon is rather transparent at the YAG wavelength, it is possible to reach the layer 7 in the center of the stack 2 , 4 by illuminating either face 13 or the opposite face of the structure. Advantage is taken of the implanted layer being naturally much more highly absorbent than the initial crystal, even when implantation is performed using protons. It is also possible to increase its absorption strongly by implanting ions of phosphorus or of arsenic or of any other suitable element. It should be observed that under such circumstances, the expansion wave created is about twice that obtained in the preceding case, other parameters remaining identical. Furthermore, implementation is simplified since it is no longer necessary to ensure that the layer where the energy is deposited is parallel with the implanted layer since they are now the same layer. This disposition also presents the advantage of not requiring the bonding operation whose traction strength must be very high. Each of the two portions that result from cleaving the implanted layer 7 receives a clean impulse. In other words, the bonded interface 3 is subjected only to a compression wave, providing that the face opposite to the surface 13 has deposited thereon a mechanically matching medium that enables the compression sound wave to be received so that it does not reflect in expansion from that face. This medium or damper can be constituted by a plate of silica having a thickness of 10 mm or 20 mm and which is permanently or temporarily bonded to the face opposite to face 13 .
The invention can be used for industrial manufacture of a substrate of the SOI type.
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A method of cutting at least one thin layer from a substrate or ingot forming element for an electronic or optoelectronic or optical component or sensor. This method includes the steps of forming a weakened zone in the substrate or ingot forming element, wherein the weakened zone has a thickness that corresponds to that of the layer that is to be removed; and directing a pulse of energy into the substrate or forming element wherein the pulse has a duration shorter than or of the same order as that needed by a sound wave to pass through the thickness of the weakened zone. The energy of the pulse is sufficient to cause cleavage to take place in the weakened zone as the energy of the pulse is absorbed therein.
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FIELD OF INVENTION
The present invention relates to hoisting devices. Particularly it pertains to a new lifting device used in conjunction with a ladder for raising construction materials onto the roof of a building.
BACKGROUND OF INVENTION
Construction workers are often called upon to transport construction materials and equipment onto the roof portion of a building. The materials may include roofing shingles, plywood sheets, bricks, ventilation units or even ornamental structures. Various lifting devices have been employed to accomplish this task. Such devices often require multiple persons to operate, have limited safety features and are often quite expensive to purchase and maintain.
Applicant proposes a load lifting system used in conjunction with a ladder to move a load to the roof of a building. The system is comprised of a carriage that rolls along the rails of conventional extension ladders and a self-contained hoisting mechanism for raising a load to the roof surface of a building.
The carriage of Applicant's lifting system includes a dual braking mechanism that reduces the risk of a loaded carriage sliding or rolling down the ladder during a lift or off of the roof once the load is brought to the roof surface. Applicant's lifting system also includes ladder rail adaptors to provide for a smooth transition of the carriage as it rolls along the rails of extension ladders and an eave adaptor to provide for a smooth roll surface between the ladder rails and the roof surface. The proposed lifting system also includes an infinitely adjustable ladder support to provide an intermediate support to the extension ladder.
SUMMARY OF INVENTION
The present invention provides a hoisting system for use in conjunction with a ladder to lift loads to a roof surface. The device is primarily intended to lift materials to the surface of pitched roofs typically used in residential construction. The device may also be employed to raise loads to flat or substantially flat roofs or to various levels of a wall during its construction and it may be of particular use in the construction of masonry walls.
The hoisting system is comprised of a load-bearing carriage having a roller axle and wheel assembly that allows the loaded carriage to roll up the rails of a ladder on its axels and then roll along a roof surface on the provided wheels to a desired unloading area. A rail guide is provided to maintain alignment of the carriage as it travels on the ladder rails.
A self-contained hoisting means is provided to roll the carriage along the ladder rails and along the roof surface. The hoisting means includes a roof anchor mechanism that adapts to the pitch of the roof in which it is used and thus allows for its employment on roofs having a variety of different roof slopes. The hoisting means is further comprised of a winch mechanism and pull cable arrangement having a support that works in cooperation with the roof anchor mechanism.
The carriage is further provided with a dual breaking mechanism as a safety device. The first breaking mechanism is comprised of a breaking bar that slides over the ladder rungs during a lift up the ladder but provides a positive stop against a ladder rung in the event of an untoward reversal of the carriage during the lift. The second breaking mechanism is comprised of elongated spikes that dig into the roofing surface and serve to hold the carriage on the roof in the event of an untoward reversal of the carriage while it is on a roofing surface.
Adaptors are provided for the ladder rails to allow for a smooth transition of the carriage between ladder rail extensions and from the ladder rails to the roof surface.
An infinitely adjustable ladder support is provided to give support to the extension ladder a point between its ends. This allows the user of the device to reduce the angle of the lift and as a consequence increase the lift capacity of the hoisting device.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a perspective view of the ladder hoisting assembly.
FIG. 2 is a perspective top view of the ladder hoist carriage.
FIG. 3 is a perspective bottom view of the ladder hoist carriage.
FIG. 4 is an end view of the ladder hoist carriage on a ladder.
FIG. 5 is a side perspective view of the winch assembly.
FIG. 6 is a perspective view of the roof anchor.
FIG. 7 is a perspective view of the roof eave guide bar.
FIG. 8 is a perspective view of the ladder extension rail transition assembly.
FIG. 9 is a cross sectional view of the hoisting apparatus.
FIG. 10 is a perspective view of the ladder hoisting assembly ready for a hoist.
FIG. 11 is a perspective view of a load carriage.
FIG. 12 is a cross sectional view of the hoisting apparatus during a hoist.
FIG. 13 is a side view of the hoisting assembly on a roof surface.
FIG. 14 is a perspective view of the ladder support.
FIG. 15 is a cross sectional view of the ladder support adjustment clamp.
DRAWINGS
Reference Numerals
10
Lifting Hoist System
12
Carriage
14
Hoisting Assembly
16
Winch Assembly
18
Roof Anchor
20
Winch Cable
22
Ladder
23
Ladder Rail
23A
Ladder Extension Rail
24
Ladder Rungs
25
Ladder Support
26
Carriage Frame
27
Carriage Deck Assembly
27A
First Deck Portion
27B
Second Deck Portion
28
Carriage Deck Hinge
29
Deck Load Support Bar
29A
Load Support Bar
30
Carriage Axle
Adjustment Screw
30A
Axle Bearing
32
Carriage Axle
32A
Axle Bearing
34
Carriage Wheel
36
Carriage load stop
38
Lower Load Stop Frame
40
Lower Load Stop Frame
42
Upper Load Stop Frame
Columns
44
Upper Load Stop Columns
46
Load Stop Brace
46A
Load Stop Brace Support
48
Load Stop Adjustment Screw
50
Carriage Brake Assembly
52
Ladder Rung Brake Bar
54
Carriage Ladder Brake
56
Carriage Ladder Brake Rung
bearing
Stop
58
Carriage Roof Brake
60
Carriage Roof Brake Claw
Assembly
62
Carriage Roof Brake
64
Carriage Ladder Brake
Bearing
Support Pins
66
Carriage Brake Engagement
68
Brake Engagement Lever
Lever
Bearing
69
Brake/Carriage Deck Latch
70
Carriage Hitch Bar
71
Carriage Hitch Ring
72
Rail Guide Assembly
74
Rail Guide
75
Rail Guide Adjustment plate
76
Rail Guide Adjustment Slot
78
Rail Guide Adjustment Screw
80
Winch
81
Winch spool
82
Winch Support Frame
83
Cable Guide
84
Winch Support Roof
85
Winch Support Carriage Hitch
Anchor Stops
86
Roof Anchor Bar
86A
Roof Anchor legs
86B
Roof Anchor legs
87
Roof Anchor Winch Supports
88
Roof Anchor Cable Hitch
89A
Roof Anchor Pad
89B
Roof Anchor Pad
90
Roof Anchor Pad Bearing
91
Roof Anchor Spike Guide
92
Ladder Roof Eave Guide Bar
93
Eave Guide Bar Attachment
95
Eave Guide Bar Bolt
Tab
96
Ladder Extension Rail
Transition Assembly
97
Ladder Transition Rail
98
Ladder Transition Rail
Support Plate
98A
Transition Rail Filler Plate
99
Ladder Transition Support
Plate Bolt
101
Ladder Support Base
102
Ladder Base Legs
103
Ladder Support Pole
103A
Lower Support Pole Segment
103B
Upper Telescoping Support
Pole Segment
104
Ladder Support Adjustment
104A
Ladder Support Adjustment
Clamp
Clamp
104B
Ladder Support Spring
104C
Ladder Support Spring Stop
105
Ladder Rung Support Bar
106
Ladder Rung Cradle
200
Building
210
Roof
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings and more particularly FIG. 1 , there is shown a prospective view of the hoisting system 10 of applicant's invention. The hoisting system 10 is typically used to lift materials from the ground or from a truck bed onto the roof of a building 200 . The system 10 is comprised of a hoisting assembly 14 used to hoist loads up a ladder 22 that extends to the roof 210 of the building 200 . The ladder 22 is shown as an extension ladder having lower ladder rails 23 and upper ladder extension rails 23 A, though single section, non-extending, ladders may also be utilized. As may be required, the extension ladder 22 may be supported as desired by a telescoping ladder support 25 .
The hoisting assembly 14 is comprised of a carriage 12 that rolls along and is supported by the rails 23 and 23 A of the ladder assembly. A winch assembly 16 having a winch cable 20 is used, in conjunction with a roof anchor 18 attached to the ridge of the roof 210 , to roll the carriage 12 along the ladder 22 to the roof 210 .
FIG. 2 , a top prospective view of the carriage 12 , and FIG. 3 , a bottom prospective view of the carriage 12 show the components of the carriage 12 . The carriage 12 is comprised of a frame 26 having carriage axles 30 and 32 supported on axle bearings 30 A, 32 A for rollably supporting the carriage 12 on the rails 23 and 23 A of the extension ladder 22 . Each carriage axle 30 , 32 has carriage wheels 34 that allow the carriage 12 to be rolled along the roof surface 210 when the carriage transitions from the rails 23 , 23 A of the ladder 22 to the roof surface 210 .
A carriage deck assembly 27 is supported on the frame 26 . The carriage deck assembly 27 has a first deck portion 27 A a second deck portion 27 B. These deck portions 27 A and 27 B are pivotally attached to the carriage frame 26 by means of carriage deck hinges 28 . To minimize load shifting during a lift the carriage 12 is provided with a deck load support bar 29 adjustably mounted to the frame 26 by means of a load support bar adjustment screw 29 A.
The carriage 12 has a carriage load stop 36 which is comprised of a lower load stop frame 38 having tubular lower load stop frame columns 40 and an upper load stop frame 42 having upper load stop columns 44 that slidably fit into the tubular support columns 40 and held in place by means of adjustment screw 48 . This arrangement allows for telescopic adjustment of the height of the load stop 36 . The load stop 36 has a load stop brace 46 mounted on load stop brace support 46 A attached to the upper load stop frame 42 . The upper load stop frame 42 may be reversed to position the load support brace 46 atop a load carried on the deck surface 27 .
The carriage 12 is provided with a carriage hitch bar 70 mounted to the frame 26 of the carriage 12 . The carriage hitch bar 70 has a carriage hitch ring 71 for attachment of the cable 20 from the winch assembly 16 .
Referring to FIG. 3 , the carriage brake assembly 50 is shown below the deck 27 of the carriage 12 . The carriage brake assembly 50 is comprised of a ladder rung brake bars 52 having an upwardly canted configuration that pivots about the axle 30 by means of a ladder brake bearing 54 . This pivotal mounting allows the brake bar 52 to slide over ladder rungs 23 , 23 A as the carriage 12 is pulled up the ladder 22 . The ladder brake bars 52 support a ladder brake rung stop 56 at their ends. The rung stop 56 will slide over the ladder rungs 23 and 23 A during a lift but will fall down to engage a ladder rung 24 in the event the carriage 12 rolls down the ladder 22 during the hoisting of a load.
The carriage brake assembly 50 also includes a roof brake assembly 58 . The roof brake assembly 58 is comprised of a roof brake claw 60 that is pivotally mounted on the axle 30 between the ladder rung brake bars 52 by means of roof brake bearings 62 . Upper and lower carriage ladder support pins 64 attached to the claw 60 impede the full rotation of the roof brake claw 60 on the axle 30 . The pins 64 engage the brake bars 52 and allow the carriage brake claw 60 to dig into a roof surface when the carriage 12 rolls down a roof surface.
The carriage brake assembly 50 and roof brake assembly 58 are engaged and disengaged by means of a brake engagement lever 66 that pivots on a brake engagement lever bearing 68 mounted on the roof brake claw assembly 58 . When the brake assembly is disengaged the lever 66 is upwardly biased against the carriage hitch bar 70 . To engage the braking system prior to making a lift, the engagement lever 66 is pivoted off of the hitch bar 70 to allow the claw 60 of the roof brake assembly 58 and the brake bars 52 of the carriage brake assembly 50 to freely pivot on the axle 30 .
The carriage brake assembly 50 and roof brake assembly 58 can also be completely disengaged, as shown in FIG. 9 , to avoid its contact with the ladder rungs 23 , 23 A and roof 210 to allow the carriage 12 to roll down the roof and the ladder. This is accomplished by means of a brake deck latch 69 positioned below the carriage deck 27 B. Raising the carriage bar 52 for engagement in the deck latch 69 allows the carriage 12 to be rolled down the ladder and/or roof and also identifies to a user that the brake assemblies 50 and 58 are disengaged.
In FIG. 4 , an end view of the carriage 12 , rail guide assemblies 72 are shown mounted to the carriage frame 26 to steer the carriage 12 as it rolls along the rails 23 , 23 A of the ladder 22 . Each rail guide assembly 72 is comprised of a rail guide bar 74 positioned along the outside edges of the ladder rail 23 . The position of the rail guide bar 74 with respect to the ladder rail 23 may be adjusted by means of the rail guide adjustment plate 75 having an adjustment slot 76 and rail guide adjustment screw 78 . The adjustment of the rail guide assembly 72 allows for the carriage 12 to be adapted to fit the various widths of a selected ladder 22 .
The winch assembly 16 of the hoist assembly 14 is shown in FIG. 5 . The winch assembly 16 is comprised of a winch 80 having a winch spool 81 and winch cable 20 . The winch 80 may be electrically powered though other sources of power may also be employed. The winch 80 may be remotely controlled by mechanical or electronic means. The winch 80 is mounted on a winch support frame 82 having a cable guide 83 . The winch support frame 82 has winch support roofing anchor stops 84 for supporting and securing the winch assembly 16 on the roof anchor 18 . The anchor stops 84 are spaced apart so as to allow them to also be supported on the ladder rails 24 if lifting the carriage to the roof surface is not desired. Winch support frame 82 also has a carriage hitch 85 for attaching the winch assembly 16 on the carriage frame 26 .
The roof anchor assembly 18 is shown in FIG. 6 . The roof anchor assembly is comprised of a roof anchor bar 86 having vertically oriented roof anchor legs 86 A and 86 B positioned along the axis of the anchor bar 86 . Transversely positioned anchor bars 87 are positioned on the anchor bar 86 for corresponding engagement with winch anchor stops 84 . Roof anchor legs 86 A, 86 B have corresponding support pads 89 A, 89 B that have perforations serving as nail, spoke or screw guides 91 . The spike guide 91 allows the anchor pads 89 A, 89 B to be secured to the roof surface 210 by nails or other means. The roof anchor leg 86 B is somewhat longer than roof leg 86 A to allow it to engage the roof surface on the opposite side of the roof ridgeline. The roof anchor leg 86 B is pivotally attached by means of roof anchor leg bearing 90 to the roof support pad 89 B to facilitate its alignment with the roof surface. While the roof anchor 18 may be utilized without the use of nailing the pads to the roof surface, such nailing allows a further measure of safety for the user.
FIG. 7 shows an adaptor piece for a typical extension ladder 22 to more readily allow the carriage 22 to be moved from the ladder 22 onto the roof 210 . This is accomplished by means of attaching an eave guide bar 92 to the ends of the ladder rails 23 or 23 A, as may be the case. Each eave guide bar 92 is pivotally attached to the ladder rails 23 A, as shown in FIG. 7 , by means of an attachment tab 93 and a guide bar bolt 94 . The pivotal attachment of the guide bar 92 allows for adjustment to roofs of various pitches or inclines.
FIG. 8 shows a rail transition assembly 96 for use in adapting a typical extension ladder to facilitate travel of the carriage 12 along the ladder rails 23 to ladder rails 23 A. When the rails of the typical extension ladder are extended, there is a difference in rail height and in rail spacing width from one section of the ladder to the other. The ladder rail transition assembly 96 adapts the ladder rails to allow for a smooth transition in rail height and rail spacing width from one rail section to another. The rail transition assembly 96 is comprised of a ladder transition rail 97 secured to ladder extension rail 23 A. The ladder transition rail rests on the top of ladder rail 23 as shown in FIG. 8 . Transition rail 97 is pivotally attached to the transition rail 23 A by means of transition support plate bolt 99 and transition rail filler plate 98 A if required. The transition rail assembly 96 is thus adaptable to ladders of varying dimensions.
Referring again to FIG. 1 , the hoisting assembly 10 is shown being prepared for an initial lift to the roof surface. To make such a lift, a user would climb the ladder 22 to the roof surface 210 and secure the anchor assembly 18 at the ridge of the roof. The cable 20 is then extended from the winch assembly 16 , mounted on the carriage 12 by means of the winch carriage hitch 85 , to the roof anchor assembly 18 and attached to the cable hitch 88 . Engagement of the winch 80 of the winch assembly 16 will pull the carriage 12 by means of the cable 20 on the axle rollers 30 , 32 along the ladder rails 23 , 23 A to the surface of the roof 210 . When the carriage 12 reaches the roof's surface, the carriage 12 will roll along the roof 210 by means of the wheels 34 . At this stage, the carriage 12 is held in place on the roof surface by means of wheel chocks or an intermediate support cable (not shown) temporarily placed between the carriage 12 and the anchor assembly 18 . This allows for the winch assembly 16 to be removed from the carriage 12 and mounted on to the anchor assembly 18 by means of the winch supports 87 and winch anchor stops 84 . The cable 20 is extended from the roof anchor 18 and winch assembly 16 and attached to the carriage hitch ring 71 of the carriage hitch bar 70 .
To lower the carriage 12 from the roof surface to 210 and down the extension ladder 22 , the break assemblies 50 and 58 are disengaged by means of lifting the deck 27 B to expose the brake/carriage deck latch 69 and then lifting the ladder rung brake bar 52 and placing the brake rung stop 56 on the deck latch 69 . This procedure will disengage the break assemblies 50 and 58 , by holding the bars 52 and the claw 60 above the roof surface 210 and the ladder rungs 24 , so that the unloaded carriage 12 may be rolled along the roof 210 and ladder 22 . FIG. 9 shows a cross sectional view of the carriage brake assembly 50 disengaged by means of the brake/carriage brake latch 69 as described.
FIG. 10 shows the hoisting assembly 14 just prior to loading the deck 27 and hoisting the carriage 12 and the accompanying load. At this step in the process, the winch assembly 16 is mounted on the roof anchor assembly 18 , the cable 20 is connected to the carriage hitch ring 71 of the carriage 12 , and the carriage brake assembly 50 and the roof brake assembly 58 have been engaged by rotating and moving the lever 66 from its fixed position against the ladder hitch bar 70 .
FIG. 11 shows a loaded carriage 12 made ready for a lift. As shown the carriage 12 is loaded with boxes 250 representing roof materials, shingles or the like. These boxes 250 are supported on the carriage bed 27 and are prevented from shifting by means of the adjustable deck load support bars 29 . The Boxes 250 stacked on the carriage deck 27 are further supported by the load stop brace 46 . Load stop brace adjusts for the height of the boxes 250 as the upper load stop frame 42 has columns 44 which slide into the lower load stop columns 40 of the lower load stop frame 38 and the orientation can be reversed to allow the load support brace 46 to rest on top of the boxes 250 . The upper load stop frame 42 can then be held in place by means of adjustment screws 48 .
FIG. 12 shows a cross sectional view of a loaded carriage 12 in place on the ladder 22 . As it can be seen, the carriage 12 is supported on axles 30 and 32 as it rolls along the rails 23 and 23 A of the ladder 22 . The ladder break assembly 50 is shown in its engaged position impede the backward movement of the carriage 12 on the ladder 22 but allow its forward movement up the ladder 22 . Engagement of the winch 80 will pull the carriage 12 upward on the ladder 22 by means of the cable 20 . As the carriage 12 moves forward and upward on the ladder 22 , the pivoting claw 60 and the ladder rung brake bar 52 of the brake assemblies 50 and 58 glide over the ladder rungs 24 . Any downward movement of the carriage 12 on the ladder 22 would provide for engagement of the rung stop 56 of the ladder rung brake bar 52 with a rung 24 to prevent further downward movement of the carriage 12 .
FIG. 12 also shows the adjustable ladder support 25 in place to provide additional support to the ladder 22 as may be thought necessary on lifts made on longer ladder spans. The ladder support pole 103 has a lower support pole segment 103 A and an upper telescopic support pole segment 103 B that may be adjusted by means of support adjustment clamp 104 to place ladder rung cradle 106 in a desired position against a desired ladder rung 24 .
FIG. 13 shows the carriage 12 on a roof surface 210 . At this stage the carriage 12 has transitioned from the ladder 22 to the roof surface 210 by means of the ladder roof guide bar 92 . The wheels 34 allow the carriage 12 to be rolled along the roof surface by means of the cable 20 and winch assembly 16 . Should the cart 12 roll downward on the roof surface due to a defect of the winch 80 or other reason, the roof brake claw 60 of the roof brake assembly 58 will engage and dig into the roof surface 210 . Because the roof brake claw 60 pivots on roof brake bearing 62 , the roof brake claw 60 is adaptable to different types of roof surfaces and roof pitches. The carriage ladder brake support pins 64 engage and hold the pivoting brake claw 60 in place to prevent over pivoting and rotation of the claw 60 .
FIG. 14 shows the telescopically adjustable ladder support 25 . The ladder support 25 has a base 101 on which is vertically mounted a telescoping support pole 103 . The telescoping support pole 103 is comprised of a lower pole 103 A and an extendable upper support pole 103 B that is telescopically adjustable in length by means of pole adjustment mechanism 104 . The support pole 103 B includes a rung support bar 105 to which is mounted lateral rung cradles 106 . In use, the ladder support 25 is placed at a desired position under the ladder 22 and the pole 103 B is extended as desired to place the rung cradle 106 under the desired ladder rung 24 to support the ladder 22 as may be desired.
FIG. 15 shows a cross sectional detail of the ladder rung adjustment assembly 104 . The ladder support adjustment assembly 104 is comprised of a ladder support adjustment clamp 104 A and ladder support 104 B that places the adjustment clap 104 A in bias contact with support spring stop 104 C. This allows for an infinite adjustment of the extension of ladder support pole 103 B.
As can be seen from the illustrations, the carriage 12 , in combination with the ladder 22 , the roof ridge anchor 18 , and the hoist assembly 16 , provides for a self-contained hoisting assembly 14 . This hoisting assembly 14 allows the winch 60 to be transported to the roof 210 on the carriage 12 , detached from the carriage 12 , and mounted on the roof anchor 18 . The cable 20 may then be attached to the hitch ring 71 of the carriage 12 to allow the carriage 12 to be lowered down the roof and ladder 22 . The user never has to manually bring the winch 60 to the roof surface 210 to facilitate a hoisting of a load. Once the carriage 12 is off the roof 210 and on the ground or a truck bed, the deck 27 may be loaded and pulled up the ladder 22 by means of the winch assembly 16 . The process may be is repeated as necessary.
The carriage 12 may also be moved on the ladder 22 in the matter described above by placing the anchor stops 84 of the winch support frame 80 on the rungs 24 of the ladder and attaching the cable 20 to the carriage winch ring 71 . This will allow loads to move up a ladder positioned against a wall without the use of the anchor assembly 18 .
The foregoing is considered illustrative only of the principles of the invention. It may be apparent to those skilled in the art that numerous modifications and changes may be made in such details without departing from the spirit and principles of the invention.
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A hoisting device and method for hoisting material up an extension ladder. The device includes a load-carrying carriage having a wheel and roller axle assembly that also serves as rollers for engagement with the rails of the ladder. The wheel and roller axle assembly allows the cart to transition from the ladder rails to the roof surface. Also provided is a dual braking means that serves to prevent the carriage from rolling back down the ladder or off of the roof in cases of cable malfunction. The method employs a hoisting mechanism having a removable winch used in conjunction with a releasable coupled pull cable that is brought to the roof surface on the carriage, detached from the carriage, mounted on the roof and used to return the carriage to and from the roof during hoisting operations. An infinitely adjustable ladder support is provided to support the ladder during a hoist.
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[0001] This invention relates to methods of making hydrophobic matrices containing silicone pressure sensitive adhesives and solid powdered hydrophilic drugs and/or solid powdered hydrophilic excipients. More particularly, the improvement according to the invention resides in pre-forming a semi-solid composition containing the solid powdered hydrophilic drug and/or the solid powdered hydrophilic excipient, and a silicone polyether. The pre-formed semi-solid composition is then added to a silicone pressure sensitive adhesive or to a solution containing a solvent and a silicone pressure sensitive adhesive.
[0002] Silicone adhesive compositions can be pressure sensitive adhesives or permanent bonding type adhesives. Permanent bonding implies that the adhesive will actually cement two surfaces together, i.e., it behaves like a glue. Pressure sensitive, on the other hand, means that the adhesive can be stripped from a surface and re-adhered to a surface, i.e., it has the nature of the adhesive present on SCOTCH® brand tapes. While the focus of this invention is the pressure sensitive type of adhesive, the same components used herein can be used to create permanent bonding type adhesives with such components, if desired. Thus, in order to prepare an adhesive which will provide a permanent bond, it is required that a suitable crosslinking agent such as a hydrogen bearing silicone polymer and a catalyst be included along with the components of the pressure sensitive adhesive.
[0003] Typically, a silicone pressure sensitive adhesive comprises (i) a silicone resin containing monofunctional (M) units R 3 SiO 1/2 and tetrafunctional (Q) units SiO 4 , i.e., an MQ silicone resin, wherein R is a hydrocarbon group, optionally a hydrocarbon group having 1-20 carbon atoms such as methyl, ethyl, propy, hexenyl, phenyl and the like; and (ii) a polydiorganosiloxane fluid or gum, optionally a high molecular weight hydroxyl endblocked polydiorganosiloxane fluid with a viscosity of 100 to 1,000,000, alternatively 5,000 to 1,000,000 centistokes (mm 2 /s) or a high molecular weight hydroxyl endblocked polydiorganosiloxane gum where viscosity is expressed in terms of plasticity. Other ingredients know for use in silicone pressure sensitive adhesives can also be incorporated.
[0004] Silicone pressure sensitive adhesives can be prepared by simply mixing components (i), (ii) and any other optional pressure sensitive adhesive ingredients. Generally, this takes place in the presence of a mutual solvent such an organic, aromatic, hydrocarbon or silicone solvent, i.e., ethyl acetate, heptane, xylene, or toluene. However, the solvent can be omitted. As soon as the components are mixed, the composition is ready for use as a pressure sensitive adhesive without further treatment. It can simply be applied to the surfaces to be adhered by any suitable means, and then the surfaces are brought together. Typically, if the composition contains a solvent, the solvent is allowed to evaporate before adhering the two surfaces. The coating can be cured for a short time by heating it briefly, although curing is not generally required. Likewise, a catalyst can be added to assist in the curing, although a catalyst is not generally required.
[0005] While the focus of this invention is primarily directed to silicone pressure sensitive adhesives of the type described in U.S. Pat. No. 4,655,767 (Apr. 7, 1987), the '767 patent, which is considered incorporated herein by reference, other types of silicone pressure sensitive adhesives can be used, if desired. Thus, other types of silicone pressure sensitive adhesives which can be used are described, for example, in U.S. Pat. No. 2,736,721 (Feb. 28, 1956); U.S. Pat. 2,814,601 (Nov. 26, 1957); U.S. Pat. No. 2,857,356 (Oct. 21, 1958); U.S. Pat. No. 4,584,355 (Apr. 22, 1986); U.S. Pat. No. 4,585,836 (Apr. 29, 1986); U.S. Pat. No. 4,591,622 (May 27, 1986); and U.S. Pat. No. 5,482,988 (Jan. 9, 196), the '988 patent; all of which are considered incorporated herein by reference. In addition, other types of adhesives having a more suitable surface pressure sensitive adhesion property can be used, such as the so-called Soft Skin Adhesive, i.e., the siloxane gel compositions described in detail in U.S. Pat. No. 5,145,933 (Sep. 8, 1992), which are prepared from (A) alkenyl-containing polydiorganosiloxanes, (B) hydrosilicon compounds having at least three SiH groups, (C) SiH end-blocked polydiorganosiloxanes, and a (D) catalyst.
[0006] None of these references, however, either describe or suggest the method of making silicone pressure sensitive adhesive compositions according to this invention. In addition, and with particular regard to the '988 patent, the compositions prepared according to the method described in the present invention exhibit a greater resistance to deformation than the compositions in the '988 patent which possess a much lower resistance to deformation. Furthermore, while it's possible in some instances, to use the waxy type silicone polyethers of the '988 patent, in the method according to this invention, the benefits derived and attributed to the method of the present invention would be compromised.
[0007] It is known that hydrophilic drugs and/or hydrophilic excipients are not soluble in hydrophobic matrices of silicone pressure sensitive adhesives. It is also known that the addition of hydrophilic materials to silicone pressure sensitive adhesives, generally results in the formation of large crystals and/or agglomerates, and that the crystals and agglomerates cannot be evenly distributed in the matrices of silicone pressure sensitive adhesives. This results in products containing low levels of drug and/or excipient, or products containing varying and inconsistent quantities of drugs and/or excipients.
[0008] However, and in accordance with the present invention, by preparing a slurry of the hydrophilic drug and/or excipient in a silicone polyether, and then adding the pre-prepared slurry of the hydrophilic drug and/or hydrophilic excipient to a silicone pressure sensitive adhesive or to a solvated silicone pressure sensitive adhesive, the hydrophilic drug and/or the hydrophilic excipient become stable in their soluble form, or are present in the hydrophobic matrix of the silicone pressure sensitive adhesive in very small discrete particles.
[0009] Among the benefits achieved according to this invention are products containing the silicone pressure sensitive adhesive and the hydrophilic drugs and/or hydrophilic excipients possess improved physical stability and an improved rate of drug release. The presence of the silicone polyether also results in additional tack-adhesion properties which increase wear properties of transdermal patches containing the hydrophobic silicone pressure sensitive adhesive matrix. Cohesiveness of the silicone pressure sensitive adhesive is not compromised, and the silicone polyether enables skilled artisans to successfully include hydrophilic materials into the hydrophobic matrices of silicone pressure sensitive adhesives.
[0010] In particular, the present invention is directed to a method of making a hydrophobic adhesive matrix, for example one containing a silicone pressure sensitive adhesive, and a solid powdered hydrophilic drug or a solid powdered hydrophilic excipient. The steps of the method consist of (i) the formation of a semi-solid composition, i.e., slurry, containing a solid powdered hydrophilic drug or a solid powdered hydrophilic excipient, and a silicone polyether. In the second step, a silicone pressure sensitive adhesive or a solution containing a solvent and a silicone pressure sensitive adhesive are combined with the semi-solid composition. The semi-solid composition and the silicone pressure sensitive adhesive or the solution containing the solvent and the silicone pressure sensitive adhesive are mixed together to form a hydrophobic matrix. The hydrophobic matrix can then be applied to a substrate, typically human skin by means of a transdermal patch for the continuous and controlled transdermal administration of drugs.
[0011] Generally, the ratio of the solid powdered hydrophilic drug and/or the solid powdered hydrophilic excipient to the silicone polyether in the semi-solid composition is not critical. It can, for example, be in a ratio of 1:100 to 100:1, alternatively 1:10 to 10:1, and alternatively 1:1 weight ratio. When a solution of silicone pressure sensitive in a solvent is used, it typically contains 10-90 percent by weight of the silicone pressure sensitive adhesive and 10-90 percent by weight of the solvent, alternatively 30-80 percent by weight of the silicone pressure sensitive adhesive and 20-70 percent by weight of the solvent.
[0012] These and other features of the invention will become apparent from a consideration of the detailed description.
DESCRIPTION
[0013] The term drug as used herein is intended to mean substances defined as drugs under the Federal Food, Drug, and Cosmetic Act, Pub. L. No. 75-717, 52 STAT. 1040 (1938), 21 USC Sec. 201. [321]. Generally, drugs according to Sec. 201 [321] (g)(1) (B) and (C) are substances intended for use in the diagnosis, cure, mitigation, treatment, or prevention of disease in man or other animals; and substances, other than food, intended to affect the structure or any function of the of the body of man or other animal.
[0014] Some representative examples of such substances are (i) drugs that act upon the central nervous system such as clozapine, risperidone, chordiazepoxide, buspirone, desipramine, maprotiline, amitriptyline, timolol, selegiline, naloxone and nalbuphine; (ii) drugs affecting renal and cardiovascular function such as acetazolamide, isosorbide, furosemide, chlorothiazide, amiloride, captopril, enalapril, lisinopril, isosorbide nitrate, nifedipine, verapamil, phenytoin, lidocaine, propranolol, amiodarone, pravastatin, probucol and ciprofibrate; (iii) drugs affecting gastrointestinal function such as cimetidine, omeprazole and ranitidine; (iv) drugs for the treatment of helminthiasis such as thiabendazole and mebendazole; (v) drugs for the treatment of microbial diseases such as trimethoprim, norfloxacin, ciprofloxacin, penicillin G nafcillin, cephalothin cefazolin, kanamycin A, neomycin, doxycycline minocycline, clarithromycin, clindamycin, flucytosine, ketoconazole, fluconazole, acyclovir and ganciclovir; (vi) drugs for the treatment of neoplastic diseases such as dacarbazine, busulfan, and triazenes; (vii) drugs for the treatment of nutrient deficiency such as folic acid, niacinamide, ascorbic acid and thiamine; (viii) drugs for hormonal replacement therapy such as estradiol, ethinyl estradiol and norethindrone; (ix) drugs that inhibit the synthesis and actions of adrenocortical hormones such as cortisol, cortisone and prednisone; and (x) drugs used in dermatology for the treatment of dermatoses such as betamethasone dipropionate, hydrocortisone, dexamethasone sodium phosphate, retinal, tretinoin, isotretinoin, dapsone, calipotriene, ketoconazole, clotrimazole, itraconazole and arotinoid.
[0015] The term excipients as used herein is intended to mean substances as defined in the Handbook of Pharmaceutical Excipients , Ray. C. Rowe, Paul J. Weller, and Arthur H. Kibbe, (Editors), as additives used to convert pharmacologically active compounds into pharmaceutical dosage forms suitable for the administration to patients. Some representative examples of such additives are (i) sugars and sugar derivatives such as acacia, dextrin, dextrose, fructose, lactose, maltodextrin, mannitol, sorbitol, sucrose, and xylitol; (ii) starch derivatives; (iii) cellulosic materials such as sodium carboxymethylcellulose, microcrystalline cellulose, cellulose acetate phthalate, sodium croscarmellose, methyl cellulose, ethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, and hydroxypropylmethylcellulose phthalate; (iv) polysaccharides such as dextrates, guar gum, and xanthan gum; (v) polyethers such as poloxamer and polyoxyethylene alkyl ethers; (vi) polyvinyl alcohols; (vii) acrylic and methacrylic acid polymers such as Carbopol, Carbomer, polacrilin potassium, and polymethacrylates; (viii) pyrrolidone derivatives such as povidone and crospovidone; (ix) glycuronam polymers and derivatives such as alginic acid and the calcium and sodium alignate salts thereof; (x) solid diluents such as the calcium and magnesium salts of carbonates, calcium phosphate derivatives, calcium sulfate, magnesium oxide, potassium chloride, and potassium citrate; (xi) solid lubricants such as calcium and magnesium stearate derivatives, talc, and zinc oxide; (xii) suspending agents such as kaolin, magnesium aluminum silicate, carbon, and cyclodextrins; and (xiii) others excipient substances such as cholesterol, fumaric acid, lecithin, gelatin, malic acid, sodium bicarbonate, sodium citrate salts, sodium stearyl fumarate, titanium dioxide, and zinc oxide.
[0016] While nearly any silicone polyether can be used, the silicone polyethers are preferably copolymeric silicone polyethers containing dimethylsiloxy units and oxyalkylene units in their molecule. These materials often have a degree of polymerization (DP) generally less than about twenty. Such silicone polyethers are well know in the art, commercially available, and described in detail in detail in U.S. Pat. No. 3,402,192 (Sep. 17, 1968), and more recently in, for example, U.S. Pat. No. 6,121,373 (Sep. 19, 2000). If desired, other types of silicone polyethers can be used, but it may result in failure to obtain all of benefits of the invention.
[0017] Thus, some representative examples of other types of silicone polyethers which may be considered can be found described in detail in the following Patents, (i) crosslinked silicone polyethers in U.S. Pat. No. 5,136,068 (Aug. 4, 1992); (ii) waxy silicone polyethers in U.S. Pat. No. 5,482,988 (Jan. 9, 1996); (iii) oligomeric silicone polyethers in U.S. Pat. No. 5,488,124 (Jan. 30, 1996); (iv) short chain low molecular weight silicone polyethers and cyclic silicone polyethers in U.S. Pat. No. 5,623,017 (Apr. 22, 1997); (v) oxyalkylene functional silanes in U.S. Pat. No. 5,707,550 (Jan. 13, 1998); (vi) elastomeric silicone polyethers in U.S. Pat. No. 5,811,487 (Sep. 22, 1998); and (vii) silicone polyethers containing arylalkyl groups in U.S. Pat. No. 6,133,370 (Oct. 17, 2000); all of which are considered incorporated herein by reference thereto.
[0018] In the context of the present invention, the term slurry is intended to mean a semi-solid composition containing a solid powdered drug and/or a solid powdered excipient, and a silicone polyether. The components of the semi-solid composition are generally present in a weight ratio of 1:100 to 100:1, alternatively 1:10 to 10:1, and alternatively 1:1, i.e., one part of the silicone polyether and one part of the drug, excipient, or drug and excipient.
[0019] The pressure sensitive adhesives used in the invention are described above. Some mutual and compatible solvents for the pressure sensitive adhesives which can be used in the method according to the invention include organic, aromatic and hydrocarbon solvents such as ethyl acetate, heptane, benzene, xylene, or toluene. Silicone fluids can also be used as solvent including low molecular weight short chain linear siloxanes such as hexamethyldisiloxane, octamethyltrisiloxane, and decamethyltetrasiloxane, and cyclic siloxanes such as octamethylcyclotetrasiloxane (D 4 ) and decamethylcylocpentasiloxane (D5). These compositions can be used in the dilution/solvation of silicone pressure sensitive adhesives. The use of a solvent is optional, however, and a solvent can be omitted in those instances where solventless silicone pressure sensitive adhesives are desired. This is common practice, for example, in the customization of solventless silicone pressure sensitive adhesives having adjustable tack.
[0020] The method of the present invention consists of first making a slurry, i.e., a semi-solid composition, of the solid powdered hydrophilic drug and/or the solid powdered hydrophilic excipient, and a silicone polyether. This slurrying process allows any agglomerations of the solid powdered hydrophilic drugs to be broken up into solutions/finely dispersed particles, which in turn prevents their random and uncontrolled crystallization. It also facilitates incorporation of such materials into other liquid silicones, i.e., liquids into liquids by matching liquid viscosity. Typically, the slurrying process provides a lower shear system, and therefore the drug stability is not significantly affected. Additionally, the use of silicone polyethers as the surfactant enables their participation in the release kinetics of the blend. Thus, it is know that hydrophilic materials such as silicone polyethers can function to increase release kinetic profiles by (i) homogeneously dispersing the hydrophilic phase, i.e., the excipient phase, and by (ii) stabilizing hydrophilic phases into hydrophobic silicone containing phases, with the result that the hydrophilic behavior or property of the blend is increased.
[0021] In the second step, the pre-formed semi-solid composition is mixed with a silicone pressure sensitive adhesive or a solution containing a solvent and the silicone pressure sensitive adhesive to form the hydrophobic matrix. As noted before, the process of this invention will function with nearly any adhesive matrix, alternatively any hydrophobic adhesive matrix.
[0022] The hydrophobic matrix can be applied to suitable backing materials or substrates by any conventional means such as roller coating, dip coating, extrusion, knife coating, or spray coating. No special equipment is needed to carry out the method, and simple laboratory mortars and pestles can be employed, as well as air-driven or electric general purpose mixers.
EXAMPLES
[0023] The following examples are set forth in order to illustrate the invention in more detail.
[0024] The silicone polyether used in these examples was a copolymeric silicone polyether containing dimethylsiloxy units and oxyalkylene units. It had a degree of polymerization (DP) of about fifteen, and its structure generally corresponded to the structure of the silicone polyether of Formula (I) in U.S. Pat. No. 6,121,373 (Sep. 19, 2000), wherein the sum of x and y were 15.
[0025] The silicone pressure sensitive adhesive used in the examples was composed of (i) an MQ resin, and (ii) a hydroxyl endblocked polydiorganosiloxane fluid having a degree of polymerization (DP), i.e., the number of repeat units, of about 1,000. It was a composition generally of the type described in U.S. Pat. No. 4,655,767 (Apr. 7, 1987).
Example 1
[0000] Ascorbyl Phosphate
[0026] Following the mixing procedure detailed above in the specification, three compositions were prepared, and the contents and amounts of the ingredients used to form the compositions are shown in Table 1. In this example, the compositions contained varying amounts of the silicone pressure sensitive adhesive (PSA), the drug sodium ascorbyl phosphate (SAP), and the silicone polyether (SPE).
TABLE 1 Silicone Pressure Sensitive Adhesive/Drug/Silicone Polyether (percent by weight) COMPOSITION PSA SAP SPE Observations 1 97 3 0 Poor dispersion and large agglomerates 2 94 3 3 Uniform slurry, fine dispersion, good tack and adhesion 3 91 3 6 Uniform slurry, fine dispersion, good tack and adhesion
[0027] In Table 1, Compositions 2 and 3 which are according to the invention, provided better dispersion properties than Composition 1 which was formulated without a silicone polyether.
Example 2
[0000] Niacinamide
[0028] Example 1 was repeated and four more compositions were prepared containing a different drug. The contents and amounts of the ingredients used to form the compositions are shown in Table 2. In this example, the compositions contained varying amounts of the silicone pressure sensitive adhesive (PSA), the drug niacinamide (NIAC), and the silicone polyether (SPE).
TABLE 2 Silicone Pressure Sensitive Adhesive/Drug/Silicone Polyether (percent by weight) COMPOSITION PSA NIAC SPE Observations 4 85 15 0 Poor dispersion and large agglomerates 5 90 5 5 Good dispersion and no agglomerates 6 80 10 10 Good dispersion and no agglomerates 7 70 15 15 Good dispersion and no agglomerates
[0029] In Table 2, Compositions 4 - 7 provided drug release rates of 46.5 percent, 64.9 percent, 51.4 percent, and 45.7 percent, respectively. This shows that Compositions 5 - 7 , which are according to the present invention, each achieved significantly improved performance than Composition 4 , which was formulated without a silicone polyether. Also, Compositions 5 - 7 , which are according to the invention, provided better dispersion properties than Composition 4 , which was formulated without a silicone polyether.
Example 3
[0030] Niacinamide and ketoconazole, the silicone polyether surfactant, and a solid excipient, were added to a solvated silicone pressure sensitive adhesive. The silicone polyether and the silicone pressure sensitive adhesive were the same compositions used in the previous examples. Laminates were prepared by using a table coater and some shims. The laminates were allowed to desolvate at ambient conditions. The laminates contained 90-100 percent by weight of the silicone pressure sensitive adhesive (PSA), 5 percent by weight of a silicone component which was either the silicone polyether (SPE) or a polydimethylsiloxane (PDMS) fluid having a viscosity of 10 centistoke (mm 2 /sec) used for comparison, and 5 percent by weight of the drugs Niacinamide or ketoconazole, based on the weight of the silicone matrix.
[0031] The drug dissolution was performed by means of Franz static diffusion cells. The drug analysis was performed by UV analysis. The physical properties of these compositions were evaluated by electron microscopy and dynamic rheological testing. The rheological testing protocol and the dynamic rheological testing equipment used herein are well known in the art, described in detail in the '767 patent, and reference may be had thereto. Thus, the rheological complex viscosity (Eta*), the elastic modulus (G′), and the viscous modulus (G″) properties, were all evaluated and determined. It should be noted that dynamic rheological testing is a useful tool for evaluating the physicochemical properties of silicone matrices over time.
[0032] The rheological results according to this example are shown in Table 3. In the Table, values such as 3.0 E+06 mean 3.0×10 6 . Table 3 indicates that there is a strong interaction of the drug and the silicone polyether in the silicone matrix. These materials, when added to the silicone pressure sensitive adhesive, increase the Eta* (complex viscosity) and the G′ (elastic modulus), which is beneficial. For example, the elastic modulus G′ is a factor used in rheological profiles for calculating cross linking density. Another contributing factor to the high rheological values for these formulations is the presence in the silicone polyether of a hydrophobic moiety which is partitioned in the hydrophobic silicone matrix. Generally, therefore, the presence of the silicone polyether in the silicone matrix increases the cohesiveness of the matrix. This is beneficial as it permits drug formulators to add additional and other types of excipients such as permeation enhancers and drug release modulators, which excipients are known to decrease rheological properties and even contribute to cold flow resulting in oozing of adhesives.
TABLE 3 Silicone Matrix Containing Silicone Pressure Sensitive Adhesive, Silicone Polyether or Polydimethylsiloxane Fluid, and Drug (Percent by Weight). Rheology Values @ 0.01 rad./sec. Matrix PSA Drug Silicone Eta* (P) G′ (dyne/cm 2 ) G″ (dyne/cm 2 ) 1 100% 0 0 3.0E+06 1.0E+04 2.5E+04 2 95% 5% 0 8.5E+07 4.4E+05 7.3E+05 Niacinamide 3 90% 5% SPE 7.4E+08 5.0E+06 4.9E+06 Niacinamide 4 95% 5% 0 7.0E+06 4.2E+04 5.6E+04 Ketoconazole 5 90% 5% SPE 1.2E+09 8.8E+06 8.2E+06 Ketoconazole 6 90% 5% PDMS 2.0E+06 1.1E+04 1.7E+04 Ketoconazole 7 90% 5% PDMS 1.6E+07 9.0E+04 1.3E+05 Niacinamide 8 90% 5% SPE 6.5E+08 4.3E+06 4.9E+06 Ketoconazole 9 90% 5% SPE 2.9E+08 1.8E+06 2.3E+06 Niacinamide
[0033] These examples also demonstrate that the presence and use of a silicone polyether as a component of the silicone matrix provides several formulating advantages. Thus, (i) the silicone polyether functions as a carrier for incorporating solid drugs in a silicone matrix, (ii) acts as a crystal retardant for the drug and the excipient, and (iii) provides good in vitro flux rates and delivery profiles. As a processing aid, it enables the content uniformity compliance. Lastly, it is multi-functional to the extent that it compatiblizes solid drugs and hydrophilic excipient solids in the silicone matrix, thereby allowing the use of a hydrophobic silicone pressure sensitive adhesive for making transdermal patches containing hydrophilic solid drugs.
[0034] Other variations may be made in compounds, compositions, and methods described herein without departing from the essential features of the invention. The embodiments of the invention specifically illustrated herein are exemplary only and not intended as limitations on their scope except as defined in the appended claims.
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A hydrophobic matrix is prepared by forming a semi-solid composition containing a solid powdered hydrophilic drug and/or a solid powdered hydrophilic excipient, and a silicone polyether, and then adding the semi-solid composition to a silicone pressure sensitive adhesive or a solution containing a solvent and a silicone pressure sensitive adhesive, and mixing the composition and the silicone pressure sensitive adhesive or the solution containing the solvent and the silicone pressure sensitive adhesive together to form the hydrophobic matrix. The hydrophobic matrix can be applied to a substrate, typically the human skin by means of a transdermal patch for continuous and controlled transdermal administration of drugs.
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CROSS-REFERENCES TO RELATED PATENT APPLICATION
[0001] The present application claims priority under 35 U.S.C 119(a) to Korean Application No. 10-2009-0032364, filed on Apr. 14, 2009, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety as set forth in full.
BACKGROUND
[0002] 1. Technical Field
[0003] The present invention relates to a semiconductor memory apparatus and, more particularly, to a memory cell of a semiconductor memory apparatus and a control circuit thereof.
[0004] 2. Related Art
[0005] A conventional dynamic random access memory (DRAM) includes numerous memory cells that are each composed of one transistor and one capacitor to store data. However, a general structure having those memory cells is not suitable to decrease an area of a memory core region, such that there is a technical limitation in improving an integration degree of a semiconductor memory apparatus. Therefore, a floating body cell (FBC) technology for implementing the transistor and the capacitor of the memory cell as one transistor has been developed.
[0006] Hereinafter, the FBC technology will be described in more detail with reference to the accompanying drawings.
[0007] FIG. 1 is a cross-sectional view of a transistor implementing an FBC and illustrates an N-type transistor as an example. It is understood herein that the drawings are not necessarily to scale and in some instances proportions may have been exaggerated in order to more clearly depict certain features of the invention.
[0008] As shown in FIG. 1 , like a general N-type MOS transistor, the transistor implementing the FBC has a structure in which a source 1 and a drain 2 doped with N-type impurities are configured on a semiconductor substrate and a gate electrode 3 and a gate oxide layer 4 are formed at a predetermined region of a top part of the source 1 and the drain 2 . However, an insulating layer 5 is provided in a center portion of a body region. Therefore, the body region is divided into a floating body part 6 and a substrate part 7 . At this time, the floating body part 6 and the substrate part 7 are doped with P-type impurities.
[0009] The insulating layer 5 is interposed between the floating body part 6 and the substrate part 7 , such that holes are accumulated in the floating body part 6 by voltages respectively applied to the source 1 , the drain 2 , and the gate electrode 3 . Therefore, a virtual capacitor is formed in the FBC. Due to characteristics of the capacitor generated as above, the transistor can be utilized as a memory cell having a structure in which a switching transistor and the memory cell are combined with each other.
[0010] In order to implement the FBC technology, a predetermined voltage must be accurately applied to each of the source, the drain, and the gate of the transistor in a read operation or a write operation. Further, in the FBC technology, a support for a hold operation is required as well as the read and write operations and an operation of inputting a logical value of ‘1’, and an operation of inputting a logical value of ‘0’ need to be distinguished even during the write operation.
[0011] Likewise, levels of voltages to be applied to the source, the drain, and the gate are shown in Table 1 depending on each operation.
[0000]
TABLE 1
Write ‘1’
Write ‘0’
Read
Hold
operation
operation
operation
operation
Source
2.5 V
2.5 V
2.5 V
0 V
voltage
Drain
0 V
0.5 V
0 V
0 V
voltage
Gate voltage
0.5 V
0.5 V
−1.0 V
−1.5 V
[0012] As seen from Table 1, a cell transistor in the FBC technology should be applied with voltages set at a source, a drain, and a gate thereof at the time of performing four different operations. For this, a circuit for supplying a voltage to each of the source, the drain, and the gate of the cell transistor for each operation should be provided.
[0013] Up to now, the FBC technology is difficult to utilize as the memory cell of the semiconductor memory apparatus because circuits for supplying voltages to the source, the drain, and the gate of each cell transistor have not yet been developed. Moreover, data of the semiconductor memory apparatus adopting the FBC technology are also volatile like in the DRAM. Therefore, even herein, a refresh operation should be performed and the relevant technical configuration should be provided. As such, development of relevant circuits is keenly necessary in order to adopt the FBC technology for improving the integration degree of the semiconductor memory apparatus.
SUMMARY
[0014] The present invention provides a semiconductor memory apparatus and a refresh control method of the same that can implement an FBC technology in a cell transistor of a memory core region.
[0015] In a first embodiment, a semiconductor memory apparatus includes a memory cell block comprising a plurality of floating body cell (FBC) transistors, each FBC transistor having a gate connected to a word line, a drain connected to a bit line, and a source connected to a source line, wherein FBC transistor pairs are formed by sharing the source lines in the FBC transistors, wherein when a refresh signal is enabled, the semiconductor memory apparatus is configured to read data stored in the memory cell block in response to an enabled refresh read signal and then rewrite the read data in the memory cell block in response to an enabled refresh write signal.
[0016] In a second embodiment, a semiconductor memory apparatus includes a refresh controller configured to generate a refresh enable signal, a refresh read signal, a refresh write signal, and a refresh sense amp enable signal in response to a refresh signal; a row operation controller configured to supply voltages to a word line and a source line of a memory cell block in response to the refresh read signal and the refresh write signal when the refresh enable signal is enabled; a column operation controller configured to amplify data transferred from a bit line of the memory cell block in response to the refresh read signal, the refresh sense amp enable signal, and the refresh write signal when the refresh enable signal is enabled and configured to supply a voltage corresponding to the amplified data to the bit line; and a data bus switch configured to interrupt outputting of the amplified data to a data input/output bus when the refresh enable signal is enabled.
[0017] In a third embodiment, a semiconductor memory apparatus includes a row refresh counter configured to generate a row counting signal and a source counting signal by performing a counting operation when a refresh enable signal is enabled; a row address decoder configured to generate a row selection signal by decoding the row counting signal; a source address decoder configured to generate a source selection signal by decoding the source counting signal; a row operation controller configured to sequentially supply voltages to a plurality of word lines and a plurality of source lines of a memory cell block in response to the row selection signal and the source selection signal when the refresh enable signal is enabled; a column refresh counter configured to generate a column counting signal by performing the counting operation when the refresh enable signal is enabled; a column address decoder configured to generate a column selection signal by decoding the column counting signal; and a column operation controller configured to sequentially rewrite data of a plurality of bit lines of the memory cell block in response to the column selection signal when the refresh enable signal is enabled.
[0018] In a fourth embodiment, a refresh control method of a semiconductor memory apparatus including a memory cell block having a plurality of floating body cell (FBC) transistors having a gate connected to a word line, a drain connected to a bit line, and a source connected to a source line, wherein FBC transistor pairs are formed by sharing the source lines in the FBC transistors, the refresh control method includes enabling a refresh read signal when a refresh signal is enabled; outputting data from any one memory cell by supplying voltages to the word line, the source line, and the bit line in response to the refresh read signal; disabling the refresh read signal and enabling a refresh write signal; and rewriting the data in the bit line by supplying a voltage having a level corresponding to a logical value of data output from the memory cell in response to the refresh write signal.
[0019] In a fifth embodiment, a refresh control method of a semiconductor memory apparatus including a memory cell block composed of a plurality of floating body cell (FBC) transistors, each FBC transistor having a gate connected to a word line, a drain connected to a bit line, and a source connected to a source line, wherein FBC transistor pairs are formed by sharing the source lines in the plurality of the floating body cell transistors, the refresh control method includes supplying voltages for a read operation or a write operation to a first word line and a first source line when a refresh enable signal is enabled; sequentially performing a rewriting operation of data in the plurality of bit lines; deactivating the first word line and supplying a voltage for the read or write operation to a second word line; sequentially re-performing the rewriting operation of data for the plurality of bit lines; and deactivating the second word line and the first source line and activating a third word line and a second source line.
[0020] These and other features, aspects, and embodiments are described below in the section “Detailed Description.”
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Features, aspects, and embodiments are described in conjunction with the attached drawings, in which:
[0022] FIG. 1 is a cross-sectional view of a transistor implementing an FBC;
[0023] FIG. 2 is a block diagram illustrating a configuration of a memory core region of a semiconductor memory apparatus according to one embodiment;
[0024] FIG. 3 is a waveform diagram for illustrating an operation of a refresh controller of FIG. 2 ;
[0025] FIG. 4 is a configuration diagram of an exemplary memory cell block of FIG. 2 according to one embodiment;
[0026] FIG. 5 is a configuration diagram of an exemplary word line driver of FIG. 2 according to one embodiment;
[0027] FIG. 6 is a configuration diagram of an exemplary source line driver of FIG. 2 according to one embodiment;
[0028] FIG. 7 is a configuration diagram of an exemplary bit line multiplexer of FIG. 2 according to one embodiment; and
[0029] FIG. 8 is a configuration diagram of exemplary sense amplifier and bit line driver of FIG. 2 according to one embodiment.
DETAILED DESCRIPTION
[0030] FIG. 2 is a block diagram illustrating a configuration of a memory core region of a semiconductor memory apparatus according to one embodiment.
[0031] As shown in FIG. 2 , the semiconductor memory apparatus can include a refresh controller 10 , a row refresh counter 11 , a row address decoder 12 , a source address decoder 13 , a row operation controller 14 , a column refresh counter 15 , a column address decoder 16 , a column operation controller 17 , a data bus switch 18 , and a memory cell block 19 .
[0032] The refresh controller 10 can generate a refresh enable signal ‘rfen’, a refresh read signal ‘rfrd’, a refresh write signal ‘rfwt’ and a refresh sense amp enable signal ‘rfsaen’ in response to a refresh signal ‘rfsh’. The row refresh counter 11 can generate a plural-bit row counting signal ‘rcnt’ and a plural-bit source counting signal ‘scnt’ by performing a counting operation in response to the refresh enable signal ‘rfen’. The row address decoder 12 can generate a plural-bit row selection signal ‘xs’ by decoding the row counting signal ‘rcnt’ in response to the refresh enable signal ‘rfen’. The source address decoder 13 can generate a plural-bit source selection signal ‘ss’ by decoding the source counting signal ‘scnt’ in response to the refresh enable signal ‘rfen’. The row operation controller 14 can supply voltages to a plurality of word lines ‘WL’ and a plurality of source lines ‘SL’ in response to the refresh enable signal ‘rfen’, a normal row read signal ‘nrrd’, the refresh read signal ‘rfrd’, a normal row write signal ‘nrwt’ the refresh write signal ‘rfwt’ the plural-bit row selection signal ‘xs’ and the plural-bit source selection signal ‘ss’.
[0033] The column refresh counter 15 can generate a plural-bit column counting signal ‘ccnt’ by performing the counting operation in response to the refresh enable signal ‘rfen’. The column address decoder 16 can generate a plural-bit column selection signal ‘ys’ by decoding the plural-bit column counting signal ‘ccnt’ in response to the refresh enable signal ‘rfen’. The column operation controller 17 can amplify and output data transmitted from any one of a plurality of bit lines ‘BL’ as amplification data ‘d_amp’ or drive and transfer input data ‘d_in’ to any one of the plurality of bit lines ‘BL’ in response to the refresh enable signal ‘rfen’ a normal column read signal ‘ncrd’ the refresh read signal ‘rfrd’, a normal column write signal ‘ncwt’, the refresh write signal ‘rfwt’, a normal sense amp enable signal ‘nsaen’, the refresh sense amp enable signal ‘rfsaen’, and the plural-bit column selection signal ‘ys’. The data bus switch 18 can interrupt outputting the amplification data ‘d_amp’ to a data input/output bus IOBUS and inputting data transferred from the data input/output bus IOBUS into the column operation controller 17 in response to the refresh enable signal ‘rfen’. The memory cell block 19 are connected to the plurality of word lines ‘WL’, the plurality of source lines ‘SL’, and the plurality of bit lines ‘BL’. The memory cell block 19 includes a plurality of memory cells.
[0034] The refresh controller 10 can generate the refresh enable signal ‘rfen’, the refresh read signal ‘rfrd’, the refresh write signal ‘rfwt’, and the refresh sense amp enable signal ‘rfsaen’ in response to the refresh signal ‘rfsh’, as described above. Waveforms of the signals are shown in FIG. 3 .
[0035] FIG. 3 is a waveform diagram for illustrating an operation of a refresh controller of FIG. 2 .
[0036] Referring to FIG. 3 , the refresh enable signal ‘rfen’ has a predetermined enable interval. In this interval, after the refresh read signal ‘rfrd’ is enabled and then disabled, the refresh write signal ‘rfwt’ is enabled and then disabled. The refresh sense amp enable signal ‘rfsaen’ has a wave form similar to the refresh read signal ‘rfrd’.
[0037] This waveform is illustrated for only a refresh operation with respect to one memory cell that is included in the memory cell block 19 . The operation is repeated at as many times as memory cells during the refresh operation is performed. A configuration of the refresh controller 10 that generates the signals having the waveform can be easily implemented by those skilled in the art. Therefore, a detailed configuration of the refresh controller 10 will be omitted.
[0038] The memory cell block 19 includes a plurality of memory cells implemented by an FBC transistor. The word lines ‘WL’ are provided as many as the rows of the plurality of memory cells, the source lines ‘SL’ are provided a half as many as the word lines ‘WL’, and the bit lines ‘BL’ are provided as many as the columns of the plurality of memory cells.
[0039] As a result, in order to perform the refresh operation for each memory cell, the row refresh counter 11 performs a counting operation in respects to the plural-bit row counting signal ‘rcnt’ two times faster than a counting operation in respects to the plural-bit source counting signal ‘scnt’. Further, the column refresh counter 15 performs a counting operation in respects to the plural-bit column counting signal ‘ccnt’ times as many as all the bit lines ‘BL’ faster than the counting operation of the row refresh counter 11 in respects to the plural-bit row counting signal ‘rcnt’. Accordingly, a logical value of the plural-bit column selection signal ‘ys’ generated from the column address decoder 16 varies times as may as all the bit lines ‘BL’ faster than and a logical value of the plural-bit source selection signal ‘ss’ varies two times slower than the plural-bit row selection signal ‘xs’ generated from the row address decoder 12 .
[0040] That is, the semiconductor memory apparatus sequentially performs the refresh operation in respects to the plurality bit lines ‘BL’ in a state where a predetermined word line ‘WL’ and a predetermined source line ‘SL’ are activated. Thereafter, the semiconductor memory apparatus deactivates the word line ‘WL’ and activates the other word line ‘WL’ and then repeats the above-mentioned operation. The predetermined source line ‘SL’ is activated while two word lines ‘WL’ are sequentially activated. Thereafter, when the other word line ‘WL’ is activated, the other source line ‘SL’ is activated. The semiconductor memory apparatus repetitively performs the operation so as to perform the refresh operation in respects to each of a plurality of memory cells included in the memory cell block 19 .
[0041] The row address decoder 12 and the source address decoder 13 receive a plural-bit row address ‘add_row’ in the case when the refresh enable signal ‘rfen’ is not enabled, that is, in a normal mode and performs a decoding operation in respects to the plural-bit row address ‘add_row’. Further, the column address decoder 16 receives a plural-bit column address ‘add_clm’ in the normal mode and performs a decoding operation in respects to the plural-bit column address ‘add_clm’. On the contrary, when the refresh enable signal ‘rfen’ is enabled, the row address decoder 12 and the source address decoder 13 performs the decoding operation in response to the plural-bit row counting signal ‘rcnt’ and the column address decoder 16 performs the decoding operation in response to the plural-bit column counting signal ‘ccnt’.
[0042] The row operation controller 14 can supply voltages to the plurality of word lines ‘WL’ and the plurality of source lines ‘SL’ of the memory cell block 19 in response to the normal row read signal ‘nrrd’ the normal row write signal ‘nrwt’, the plural-bit row selection signal ‘xs’, and the plural-bit source selection signal ‘ss’ in the normal mode. However, when the refresh enable signal ‘rfen’ is enabled, the row operation controller 14 can supply voltages to the plurality of word lines ‘WL’ and the plurality of source lines ‘SL’ of the memory cell block 19 in response to the refresh read signal ‘rfrd’, the refresh write signal ‘rfwt’, the plural-bit row selection signal ‘xs’, and the plural-bit source selection signal ‘ss’. At this time, the row operation controller 14 can sequentially supply predetermined voltages to the plurality of word lines ‘WL’ and the plurality of source lines ‘SL’ depending on variations of the logical values of the plural-bit row selection signal ‘xs’ and the plural-bit source selection signal ‘ss’.
[0043] Herein, the normal row read signal ‘nrrd’ and the normal row write signal ‘nrwt’ are generated when a row command decoder (not shown) decodes row commands transferred from the outside. Likewise, the normal column read signal ‘ncrd’, the normal column write signal ‘ncwt’, and the normal sense amp enable signal ‘nsaen’ are generated when a column command decoder (not shown) decodes column commands transferred from the outside.
[0044] The row operation controller 14 can include a word line driver 142 and a source line driver 144 .
[0045] The word line driver 142 can supply voltages to the plurality of word lines ‘WL’, respectively, in response to the refresh enable signal ‘rfen’, the normal row read signal ‘nrrd’, the refresh read signal ‘rfrd’, the normal row write signal ‘nrwt’, the refresh write signal ‘rfwt’, and the plural-bit row selection signal ‘xs’. The source line driver 144 can supply voltages to the plurality of source lines ‘SL’, respectively, in response to the refresh enable signal ‘rfen’, the normal row read signal ‘nrrd’, the refresh read signal ‘rfrd’, the normal row write signal ‘nrwt’, the refresh write signal ‘rfwt’, and the plural-bit source selection signal ‘ss’.
[0046] The column operation controller 17 can amplify and output data of any one of the plurality of bit lines ‘BL’ or drive and transfer the input data ‘d_in’ transferred through the data bus switch 18 from the data input/output bus IOBUS to any one of the plurality of bit lines ‘BL’ in response to the normal column read signal ‘ncrd’, the normal column write signal ‘ncwt’, the normal sense amp enable signal ‘rfsaen’, and the plural-bit column selection signal ‘ys’ in the normal mode. However, when the refresh enable signal ‘rfen’ is enabled, the column operation controller 17 amplifies data transferred from any one of the plurality of bit lines ‘BL’ in response to the refresh read signal ‘rfrd’ and the refresh sense amp enable signal ‘rfsaen’ and outputs the data as the amplification data ‘d_amp’ and thereafter, rewrites the amplification data ‘d_amp’ in the bit line ‘BL’ that outputs the data in response to the refresh write signal ‘rfwt’, in response to the plural-bit column selection signal ‘ys’. Herein, the amplification data ‘d_amp’ is rewritten by supplying a voltage at a predetermined level to the corresponding bit line ‘BL’. The plural-bit column selection signal ‘ys’ controls data to be sequentially output and rewritten from/to the plurality of bit lines ‘BL’.
[0047] Like this, in order to support the operation of rewriting the data output from the bit lines ‘BL’ during the refresh operation, the data bus switch 18 is turned off to interrupt connection between the column operation controller 17 and the data input/output bus IOBUS. However, the data bus switch 18 is turned on during the normal operation to connect the data input/output bus IOBUS with the column operation controller 17 .
[0048] The column operation controller 17 can include a sense amplifier 172 , a bit line driver 174 , and a bit line multiplexer 176 .
[0049] The sense amplifier 172 can output the amplification data ‘d_amp’ by amplifying output data ‘d_out’ in response to the refresh enable signal ‘rfen’, the normal column read signal ‘ncrd’, the refresh read signal ‘rfrd’, the normal sense amp enable signal ‘nasen’, and the refresh sense amp enable signal ‘saen’. The bit line driver 174 can output driving data ‘d_drv’ by driving the input data ‘d_in’ in response to the refresh enable signal ‘rfen’, the normal column write signal ‘ncwt’, and the refresh write signal ‘rfwt’. The bit line multiplexer 176 can transfer the driving data ‘d_drv’ to any one of the plurality of bit lines ‘BL’ or transfer data transferred by any one of the plurality of bit lines ‘BL’ to the sense amplifier 172 as the output data ‘d_out’.
[0050] The word line driver 142 can supply any one of a write gate voltage, a read gate voltage, and a hold gate voltage to an activated word line ‘WL’ depending on each of a read operation mode, a write operation mode, and a hold operation mode that are divided in response to the normal row read signal ‘nrrd’ and the normal row write signal ‘nrwt’ during the normal operation. On the contrary, the word line driver 142 can supply the voltages to the activated word line ‘WL’ in response to the refresh read signal ‘rfrd’ and the refresh write signal ‘rfwt’ that are sequentially enabled during the refresh operation. At this time, the word line driver 42 can supply a read gate voltage of −1.0V when the refresh read signal ‘rfrd’ is enabled and a write gate voltage of 0.5V when the refresh write signal ‘rfwt’ is enabled, and a hold gate voltage of −1.5V in other cases in consideration of characteristics of the FBC transistor.
[0051] Further, the source line driver 144 can supply an active source voltage or a hold source voltage to an activated source line ‘SL’ depending on each of a hold operation mode and an active operation mode (the active operation mode includes the read operation mode and the write operation mode.) that are divided in response to the normal row read signal ‘nrrd’ and the normal row write signal ‘nrwt’ during the normal operation. On the contrary, the source line driver 144 can supply the voltages to the activated source line ‘SL’ in response to the refresh read signal ‘rfrd’ and the refresh write signal ‘rfwt’ that are sequentially enabled during the refresh operation. At this time, the source line driver 144 can supply an active source voltage of 2 . 5 V when the refresh read signal ‘rfrd’ and the refresh write signal ‘rfwt’ are enabled and a hold source voltage of 0V in other cases in consideration of the characteristics of the FBC transistor.
[0052] The bit line driver 174 distinguishes whether or not to enter the write operation mode in response to the normal column write signal ‘ncwt’ during the normal operation and supplies a write drain voltage to an output line of the driving data ‘d_drv’ after determining whether the logical value of the input data ‘d_in’ is ‘0’ or ‘1’ during the write operation. On the contrary, the bit line driver 174 supplies a voltage to a bit line ‘BL’ connected through the bit line multiplexer 176 in response to the refresh write signal ‘rfwt’ during the refresh operation. In this case, the amplification data ‘d_amp’ generated when the refresh read signal ‘rfrd’ is enabled is input as the input data ‘d_in’. At this time, the write drain voltage of 0V or 0.5V is supplied to the connected bit line ‘BL’ depending on the logical value of the input data ‘d_in’ in consideration of the characteristics of the FBC transistor.
[0053] The names of the gate voltage, the source voltage, and the drain voltage are granted because the word line ‘WL’ is connected to a gate of the cell transistor in the memory cell block 19 , the source line ‘SL’ is connected to a source of the cell transistor, and the bit line ‘BL’ is connected to a drain of the cell transistor. Voltage generators for varying voltage levels of the gate voltage, the source voltage, and the drain voltage can be implemented by using various voltage generators that are provided in the semiconductor memory apparatus depending on the operation modes. It will be apparent that it is not technologically particular to those skilled in the art.
[0054] FIG. 4 is a configuration diagram of an exemplary memory cell block of FIG. 2 according to one embodiment and illustrates only an arrangement relationship of 16 cell transistors for convenience of description.
[0055] As shown in FIG. 4 , the memory cell block 19 can include four word lines ‘WL<1:4>’ four bit lines ‘BL<1:4>’, two source lines ‘SL<1:2>’, and sixteen cell transistors ‘CTR<1:16>’.
[0056] Each of the two source lines ‘SL<1:2>’ is disposed between two word lines ‘WL<1:2>’ and two word lines ‘WL<3:4>’. Each of the sixteen cell transistors ‘CTR<1:16>’ includes a gate connected to a corresponding word line ‘WL’, a source connected to a corresponding source line ‘SL’, and a drain connected to a corresponding bit line ‘BL’. The cell transistors ‘CTR<1:16>’ include transistor pairs, wherein a transistor pair is composed of two transistors that share the corresponding source line ‘SL’.
[0057] As described above, since the cell transistors according to one embodiment are fabricated by implementing the FBC technology, each memory cell needs not to have a switching transistor and a cell capacitor and each transistor can operate as the memory cell. Herein, voltages applied to a gate, a source, and a drain of each transistor should have voltage levels set depending on the operation modes, such that each transistor can perform the read, write, and hold operations. Therefore, each cell transistor can implement each operation mode depending on a voltage supplied through the word line ‘WL’, a voltage supplied through the source line ‘SL’, and the a voltage supplied through the bit line ‘BL’.
[0058] In the refresh mode, the four word lines ‘WL<1:4>’, the two source lines ‘SL<1:2>’, and the four bit lines ‘BL<1:4>’ are activated depending on sequences thereof, such that the refresh operation for each of the cell transistors ‘CTR<1:16>’ becomes possible. For example, in a state when the first word line ‘WL< 1 >’ of the four word lines ‘WL<1:4>’ and the first source line ‘SL< 1 >’ of the two source lines ‘SL<1:2>’ are activated, the four bit lines ‘BL<1:2>’ are sequentially activated, such that refresh operations for four cell transistors ‘CTR< 1 , 5 , 9 , 13 >’ are sequentially performed. Thereafter, the first word line ‘WL< 1 >’ is deactivated and the second word line ‘WL< 2 >’ is activated and the above-mentioned operation is again performed, such that refresh operations for another four cell transistors ‘CTR< 2 , 6 , 10 , 14 >’ are sequentially performed Thereafter, both the second word line ‘WL< 2 >’ and the first source line ‘SL< 1 >’ are deactivated and the third word line ‘WL< 3 >’ and the second source line ‘SL< 2 >’ are activated. In this state, the four bit lines ‘BL<1:4>’ are sequentially activated, such that refresh operations for the other four cell transistors ‘CTR< 3 , 7 , 11 , 15 >’ are sequentially performed. The semiconductor memory apparatus can perform all the refresh operations for the sixteen cell transistors ‘CTR<1:16>’ by performing the above-mentioned operations.
[0059] FIG. 5 is a configuration diagram of an exemplary word line driver of FIG. 2 according to one embodiment and illustrates only a configuration in which a voltage is supplied to any one ‘WL<i>’ of a plurality of word lines for convenience of description. It will be able to be easily analogized by those skilled in the art that the components shown in FIG. 5 are provided as many as the word lines ‘WL’.
[0060] As shown in FIG. 5 , the word line driver 142 can include a first operation mode determining unit 1422 , a first operation mode setting unit 1424 , and a first switching unit 1426 .
[0061] The first operation mode determining unit 1422 can selectively output the normal row write signal ‘nrwt’ or the refresh write signal ‘rfwt’ as a first row write signal ‘wt_r 1 ’ and selectively output the normal row read signal ‘nrrd’ or the refresh read signal ‘rfrd’ as a first row read signal ‘rd_r 1 ’, in response to the refresh enable signal ‘rfen’. The first operation mode determining unit 1422 can include a first multiplexer MUX 1 and a second multiplexer MUX 2 .
[0062] The first operation mode setting unit 1424 can generate a write mode signal ‘wtmd’, a read mode signal ‘rdmd’, and a first hold mode signal ‘hdmd 1 ’ in response to a corresponding row selection signal ‘xs<i>’ of the plurality of row selection signals ‘xs’ the first row write signal ‘wt_r 1 ’, and the first row read signal ‘rd_r 1 ’. The first operation mode setting unit 1424 can include a first NAND gate ND 1 , a second NAND gate ND 2 , a first inverter IV 1 , a second inverter IV 2 , and a first NOR gate NR 1 .
[0063] The first NAND gate ND 1 can receive the row selection signal ‘xs<i>’ and the first row write signal ‘wt_r 1 ’. The first inverter IV 1 can receive an output signal of the first NAND gate ND 1 and output the write mode signal ‘wtmd’. The second NAND gate ND 2 can receive the row selection signal ‘xs<i>’ and the first row read signal ‘rd_r 1 ’. The second inverter IV 2 can receive an output signal of the second NAND gate ND 2 and output the read mode signal ‘rdmd’. The first NOR gate NR 1 can receive the first row write signal ‘wt_r 1 ’ and the first row read signal ‘rd_r 1 ’ and output the first hold mode signal ‘hdmd 1 ’.
[0064] The first switching unit 1426 can supply any one of the write gate voltage ‘Vgwt’, the read gate voltage ‘Vgrd’, and the hold gate voltage ‘Vghd’ to the corresponding word line ‘WL<i>’ in response to the write mode signal ‘wtmd’ the read mode signal ‘rdmd’, and the first hold mode signal ‘hdmd 1 ’. The first switching unit 1426 can include a third inverter IV 3 , a fourth inverter IV 4 , a fifth inverter IV 5 , a first path gate PG 1 , a second path gate PG 2 , and a third path gate PG 3 .
[0065] The third inverter IV 3 can receive the write mode signal ‘wtmd’. The first path gate PG 1 can transfer the write gate voltage ‘Vgwt’ to the word line ‘WL<i>’ in response to the write mode signal ‘wtmd’ and an output signal of the third inverter IV 3 . The fourth inverter IV 4 can receive the read mode signal ‘rdmd’. The second path gate PG 2 can transfer the read gate voltage ‘Vgrd’ to the word line ‘WL<i>’ in response to the read mode signal ‘rdmd’ and an output signal of the fourth inverter IV 4 . The fifth inverter IV 5 can receive the first hold mode signal ‘hdmd 1 ’. The third path gate PG 3 can transfer the hold gate voltage ‘Vghd’ to the word line ‘WL<i>’ in response to the first hold mode signal ‘hdmd 1 ’ and an output signal of the fifth inverter IV 5 .
[0066] Herein, levels of the write gate voltage ‘Vgwt’, the read gate voltage ‘Vgrd’, and the hold gate voltage ‘Vghd’ may be varied depending on characteristics of the cell transistor, but are preferably 0.5V, −1.0V, and −1.5V, respectively.
[0067] The first operation mode determining unit 1422 can output the normal row read signal ‘nrrd’ and the normal row write signal ‘nrwt’ as the first row read signal ‘rd_r 1 ’ and the first row write signal ‘wt_r 1 ’, respectively, when the refresh enable signal ‘rfen’ is disabled. On the contrary, the first operation mode determining unit 1422 can output the refresh read signal ‘rfrd’ and the refresh write signal ‘rfwt’ as the first row read signal ‘rd_r 1 ’ and the first row write signal ‘wt_r 1 ’ respectively, when the refresh enable signal ‘rfen’ is enabled.
[0068] The first operation mode setting unit 1424 can enable the write mode signal ‘wtmd’ when the row selection signal ‘xs<i>’ is enabled in a state where the first row write signal ‘wt_r 1 ’ is enabled. The first switching unit 1426 can supply the write gate voltage ‘Vgwt’ to the word line ‘WL<i>’ in response to the case that the write mode signal ‘wtmd’ is enabled.
[0069] On the contrary, the first operation mode setting unit 1424 can enable the read mode signal ‘rdmd’ when the row selection signal ‘xs<i>’ is enabled in a state where the first row read signal ‘rd_r 1 ’ is enabled. The first switching unit 1426 can supply the read gate voltage ‘Vgrd’ to the word line ‘WL<i>’ in response to the case that the read mode signal ‘rdmd’ is enabled.
[0070] Meanwhile, when both the first row write signal ‘wt_r 1 ’ and the first row read signal ‘rd_r 1 ’ are not enabled, the first operation mode setting unit 1424 can enable the first hold mode signal ‘hdmd 1 ’. The first switching unit 1426 can supply the hold gate voltage ‘Vghd’ to the word line ‘WL<i>’ in response to the case that the first hold mode signal ‘hdmd 1 ’ is enabled.
[0071] Therefore, the refresh read signal ‘rfrd’ and the refresh write signal ‘rfwt’ are sequentially enabled in the refresh mode and the signals serve as the first row read signal ‘rd_r 1 ’ and the first row write signal ‘wt_r 1 ’, respectively, such that the read gate voltage ‘Vgrd’ and the write gate voltage ‘Vgwt’ are sequentially applied to the word line ‘WL<i>’. The hold gate voltage ‘Vghd’ is applied to the word line ‘WL<i>’ during an interval where the refresh read signal ‘rfrd’ and the refresh write signal ‘rfwt’ are both disabled.
[0072] FIG. 6 is a configuration diagram of an exemplary source line driver of FIG. 2 according to one embodiment and illustrates only a configuration in which a voltage is supplied to any one ‘SL<i>’ of a plurality of source lines for convenience of description. It will be able to be easily analogized by those skilled in the art that the components shown in FIG. 6 are provided as many as the source lines ‘SL’.
[0073] As shown in FIG. 6 , the source line driver 144 can include a second operation mode determining unit 1442 , a second operation mode setting unit 1444 , and a second switching unit 1446 .
[0074] The second operation mode determining unit 1442 can selectively output the normal row write signal ‘nrwt’ or the refresh write signal ‘rfwt’ as a second row write signal ‘wt_r 2 ’ and selectively output the normal row read signal ‘nrrd’ or the refresh read signal ‘rfrd’ as a second row read signal ‘rd_r 2 ’, in response to the refresh enable signal ‘rfen’. The second operation mode determining unit 1442 can include a third multiplexer MUX 3 and a fourth multiplexer MUX 4 .
[0075] The second operation mode setting unit 1444 can generate a second hold mode signal ‘hdmd 2 ’ in response to the second row write signal ‘wt_r 2 ’ and the second row read signal ‘rd_r 2 ’. The second operation mode setting unit 1444 can include a second NOR gate NR 2 that can receive the second row write signal ‘wt_r 2 ’ and the second row read signal ‘rd_r 2 ’ and output the second hold mode signal ‘hdmd 2 ’.
[0076] The second switching unit 1446 can supply the active source voltage ‘Vsac’ or the hold source voltage ‘Vshd’ to the corresponding source line ‘SL<i>’ in response to a corresponding source selection signal ‘ss<i>’ of the plural-bit source selection signals ‘ss’ and the second hold mode signal ‘hdmd 2 ’. The second switching unit 1446 can include a first transistor TR 1 , a second transistor TR 2 , a third transistor TR 3 , and a fourth transistor TR 4 .
[0077] The first transistor TR 1 includes a gate that receives the source selection signal ‘ss<i>’ and a source that is applied with the active source voltage ‘Vsac’. The second transistor TR 2 includes a gate that receives the second hold mode signal ‘hdmd 2 ’, a source that is connected to a drain terminal of the first transistor TR 1 , and a drain that is connected to the source line ‘SL<i>’. The third transistor TR 3 includes a gate that receives the second hold mode signal ‘hdmd 2 ’ and a source that is connected to the source line ‘SL<i>’. The fourth transistor TR 4 includes a gate that receives the source selection signal ‘ss<i>’, a drain that is connected to the source terminal of the third transistor TR 3 , and a source that is applied with the hold source voltage ‘Vshd’.
[0078] Herein, levels of the active source voltage ‘Vsac’ and the hold source voltage ‘Vshd’ may be varied depending on the characteristics of the cell transistor, but are preferably 2.5V and 0V, respectively.
[0079] According to the above-mentioned configuration, it can be appreciated that the second hold mode signal ‘hdmd 2 ’ is enabled when the second row write signal ‘wt_r 2 ’ and the second row read signal ‘rd_r 2 ’ are both disabled.
[0080] Therefore, when the source selection signal ‘ss<i>’ is enabled and the active operation mode, that is, the write operation mode or the read operation mode are performed, the active source voltage ‘Vsac’ is supplied to the source line ‘SL<i>’. On the contrary, when a source line activation signal ‘slact’ is enabled and the hold operation mode is performed, the hold source voltage ‘Vshd’ is applied to the source line ‘SL<i>’.
[0081] The refresh read signal ‘rfrd’ and the refresh write signal ‘rfwt’ are sequentially enabled in the refresh mode and the signals serve as the second row read signal ‘rd_r 2 ’ and the second row write signal ‘wt_r 2 ’, respectively, such that the active source voltage ‘Vsac’ is applied twice to the source line ‘SL<i>’. On the contrary, the hold source voltage ‘Vshd’ is applied during an interval where the refresh read signal ‘rfrd’ and the refresh write signal ‘rfwt’ are both disabled.
[0082] FIG. 7 is a configuration diagram of an exemplary bit line multiplexer of FIG. 2 according to one embodiment and illustrates only a configuration in which the bit line multiplexer is connected to four bit lines ‘BL<1:4>’ of a plurality of bit lines for convenience of description. Therefore, four column selection signals ‘ys<1:4>’ are also input into the configuration.
[0083] As shown in FIG. 7 , the bit line multiplexer 176 can include an input/output node Nio, a fifth transistor TR 5 , a sixth transistor TR 6 , a seventh transistor TR 7 , and an eighth transistor TR 8 .
[0084] The input/output node Nio is transferred with the driving data ‘d_drv’ from the bit line driver 174 and transmits the output data ‘d_out’ to the sense amplifier 172 . The fifth transistor TR 5 includes a gate that receives a first column selection signal ‘ys< 1 >’ and is disposed between a first bit line ‘BL< 1 >’ and the input/output node Nio. The sixth transistor TR 6 includes a gate that receives a second column selection signal ‘ys< 2 >’ and is disposed between a second bit line ‘BL< 2 >’ and the input/output node Nio. The seventh transistor TR 7 includes a gate that receives a third column selection signal ‘ys< 3 >’ and is disposed between a third bit line ‘BL< 3 >’ and the input/output node Nio. The eighth transistor TR 8 includes a gate that receives a fourth column selection signal ‘ys< 4 >’ and is disposed between a fourth bit line ‘BL< 4 >’ and the input/output node Nio.
[0085] According to the above-mentioned configuration, the bit line multiplexer 176 connects the input/output node Nio with any one of the plurality of bit lines ‘BL’ according to control of the plural-bit column selection signal ‘ys’ output from the column address decoder 16 without dividing the read operation mode, the write operation mode, and the hold operation mode. Since the sense amplifier 172 is deactivated and the bit line driver 174 is activated in the write operation mode, the driving data ‘d_drv’ can be transferred to the memory cell through any one bit line ‘BL’. On the contrary, since the bit line driver 174 is deactivated and the sense amplifier 172 is activated in the read operation mode, the output data ‘d_out’ output from any one memory cell through a predetermined bit line ‘BL’ can be output through the sense amplifier 172 .
[0086] FIG. 8 is a configuration diagram of exemplary sense amplifier and bit line driver of FIG. 2 according to one embodiment.
[0087] As shown in FIG. 8 , the sense amplifier 172 can include a third operation mode determining unit 1722 , a third operation mode setting unit 1724 , and an amplification unit 1726 .
[0088] The third operation mode determining unit 1722 can selectively output the normal sense amp enable signal ‘nsaen’ or the refresh sense amp enable signal ‘rfsaen’ as a sense amp enable signal ‘saen’ in response to the refresh enable signal ‘rfen’ and output the normal column read signal ‘ncrd’ or the refresh read signal ‘rfrd’ as a column read signal ‘rd_c’ in response to the refresh enable signal ‘rfen’. The third operation mode determining unit 1722 can include a fifth multiplexer MUX 5 and a sixth multiplexer MUX 6 .
[0089] The third operation mode setting unit 1724 can set a read operation mode in response to the column read signal ‘rd_c’ and pass the output data ‘d_out’. The third operation mode setting unit 1724 can include a ninth transistor TR 9 .
[0090] The amplification unit 1726 can output the amplification data ‘d_amp’ by amplifying the output data ‘d_out’ transmitted through the third operation mode setting unit 1724 in response to the sense amp enable signal ‘saen’. The amplification unit 1726 can be easily implemented by using a general differential amplifier circuit that operates by receiving a refresh voltage ‘Vref’.
[0091] Meanwhile, the bit line driver 174 can include a fourth operation mode determining unit 1742 , a driving unit 1744 , and a fourth operation mode setting unit 1746 .
[0092] The fourth operation mode determining unit 1742 can selectively output the normal column write signal ‘ncwt’ or the refresh write signal ‘rfwt’ as a column write signal ‘wt_c’ in response to the refresh enable signal ‘rfen’. The fourth operation mode determining unit 1742 can include a seventh multiplexer MUX 7 .
[0093] The driving unit 1744 can output a first write drain voltage ‘Vdwt 1 ’ or a second write drain voltage ‘Vdwt 2 ’ in response to the input data ‘d_in’. The driving unit 1744 can include a tenth transistor TR 10 and an eleventh transistor TR 11 .
[0094] The tenth transistor TR 10 includes a gate that receives the input data ‘d_in’, a source that is applied with the first write drain voltage ‘Vdwt 1 ’, and a drain that is connected to a first node N 1 . The eleventh transistor TR 11 includes a gate that receives the input data ‘d_in’, a drain that is connected to the first node N 1 , and a source that is applied with the second write drain voltage ‘Vdwt 2 ’.
[0095] The fourth operation mode setting unit 1746 can set a write operation mode in response to the column write signal ‘wt_c’ and output the driving data ‘d_drv’ in response to the voltage transferred from the driving unit 1744 . The fourth operation mode setting unit 1746 can include a twelfth transistor TR 12 that is controlled by the column write signal ‘wt_c’, and is connected to the first node N 1 at one end thereof and outputs the driving data ‘d_drv’ through the other end thereof.
[0096] Herein, a transmission line of the output data ‘d_out’ that is transmitted to the sense amplifier 172 and a transmission line of the driving data ‘d_drv’ that is output from the bit line driver 174 are connected to the bit line multiplexer 176 . Further, a transmission line of the amplification data ‘d_amp’ that is output from the sense amplifier 172 and a transmission line of the input data ‘d_in’ that is transmitted to the bit line driver 174 are the same line and are connected to the data bus switch 18 .
[0097] During the normal operation, the normal sense amp enable signal ‘nsaen’ and the normal column read signal ‘ncrd’ serve as the sense amp enable signal ‘saen’ and the column read signal ‘rd_c’, respectively, and the normal column write signal ‘ncwt’ serves as the column write signal ‘wt_c’. Therefore, the sense amplifier 172 and the bit line driver 174 operate in response to the normal column read signal ‘ncrd’ and the normal column write signal ‘ncwt’, respectively.
[0098] However, during the refresh operation, the refresh sense amp enable signal ‘rfsaen’ and the refresh read signal ‘rfrd’ serve as the sense amp enable signal ‘saen’ and the column read signal ‘rd_c’, respectively, and the refresh write signal ‘rfwt’ serves as the column write signal ‘wt_c’. As described above, in this case, the refresh sense amp enable signal ‘rfsaen’ and the refresh read signal ‘rfrd’ are enabled and thereafter, the refresh write signal ‘rfwt’ is enabled.
[0099] Therefore, when the refresh operation is started, the operation of the bit liner driver 174 is started after the sense amplifier 172 outputs the amplification data ‘d_amp’. At this time, since the data bus switch 18 is turned off, the amplification data ‘d_amp’ is input into the bit line driver 174 as the input data ‘d_in’. When the refresh write signal ‘rfwt’ is enabled, the bit line driver 174 applies the first write drain voltage ‘Vdwt 1 ’ or the second write drain voltage ‘Vdwt 2 ’ to a data output line depending on the logical value of the input data ‘d_in’, such that the driving data ‘d_drv’ is output.
[0100] Herein, levels of the first write drain voltage ‘Vdwt 1 ’ and the second write drain voltage ‘Vdwt 2 ’ may be varied depending on the characteristics of the cell transistor, but are preferably 0.5V and 0V, respectively.
[0101] As described above, a semiconductor memory apparatus can implement a memory cell block by using a transistor implementing an FBC technology. For this, the semiconductor memory apparatus includes a plurality of word lines that are connected to gates, a plurality of source lines that are connected to sources, and a plurality of bit lines that are connected to drains of a plurality of cell transistors of the memory cell block and applies voltages set depending on operations modes. The cell transistors that implement an FBC by the above-mentioned configuration can perform operations depending on the operation modes by dividing a read operation, a write operation and a hold operation. Like this, it is possible to remarkably reduce an occupied area of a memory core region and considerably improve an integration degree of the semiconductor memory apparatus by implementing the memory cell using the FBC technology.
[0102] Further, since data may be lost due to characteristics of an FBC transistor, a refresh operation should be implemented. For this, when a refresh signal is enabled, the semiconductor memory apparatus enables a refresh read signal and outputs data from any one memory cell by supplying voltages to a word line, a source line, and a bit line. Thereafter, the semiconductor memory apparatus disables the refresh read signal and enables a refresh write signal, and then rewrites the data in the bit line by supplying a voltage having a level corresponding to a logical value of the data output from the memory cell to the bit line.
[0103] The semiconductor memory apparatus sequentially performs refresh operations for a plurality of bit lines in a state when a word line and a source line are activated and performs the above-mentioned operations after activating the other word line again. Thereafter, the semiconductor memory apparatus performs the above-mentioned operations again after activating the other word line and another source line. The semiconductor memory apparatus can perform refresh operations for all memory cells in the memory cell block by repetitively performing the operations. The semiconductor memory apparatus can stably store the data by performing the refresh operation.
[0104] While certain embodiments have been described above, it will be understood to those skilled in the art that the embodiments described are by way of example only. Accordingly, the apparatus described herein should not be limited based on the described embodiments. Rather, the apparatus described herein should only be limited in light of the claims that follow when taken in conjunction with the above description and accompanying drawings.
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A semiconductor memory apparatus and refresh control method are presented. The semiconductor memory apparatus includes a memory cell block composed of a multiplicity of floating body cell (FBC) transistors. Each FBC transistor has a gate connected to a word line, a drain connected to a bit line, and a source connected to a source line. FBC transistor pairs are formed by sharing the source lines in the plurality of the floating body cell transistors. When a refresh signal is enabled, the semiconductor memory apparatus is configured to read data stored in the memory cell block by enabling a refresh read signal and then configured to rewrite the read data in the memory cell block by enabling a refresh write signal.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an air-fuel ratio detecting device and a method therefore and particularly, to an air-fuel ratio detecting device and a method which correctly and very precisely detects the air-fuel ratio in an internal combustion engine based upon the characteristics of each limiting current type air-fuel ratio sensor and each air-fuel ratio sensor circuit.
2. Description of the Related Art
There has been known a linear air-fuel ratio sensor which is disposed in the exhaust system of an internal combustion engine (hereinafter referred to as an engine), and which detects the air-fuel ratio in the engine from the exhaust gas of the engine and generates an output which is proportional to the air-fuel ratio that is detected. In a device for controlling the air-fuel ratio by feedback with the use of the air-fuel ratio sensor according to the prior art, a map for calculating the air-fuel ratio in the engine corresponding to the output of the air-fuel ratio sensor is formed in advance through a bench test, the formed map is stored in a storage circuit, the air-fuel, ratio in the engine is calculated from the map and from the output of the air-fuel ratio sensor mounted on the real engine, and the air-fuel ratio in the engine is so controlled by feedback as to approach a target air-fuel ratio, for example, a stoichiometric air-fuel ratio at which the exhaust gas of the engine is best purified.
However, in such an air-fuel ratio feedback control device according to the prior art as described above, an air-fuel ratio sensor and a processing circuit (hereinafter referred to as an air-fuel ratio sensor circuit) for supplying electric power to the air-fuel ratio sensor and processing the output from the air-fuel ratio sensor, used for the bench check to form the map for calculating the air-fuel ratio in the engine, are different from those really use for the engine. Therefore, the air-fuel ratio in the engine that is really detected involves an error. In other words, it does not serve as a correct value, lacks reliability in controlling the air-fuel ratio by feedback, and makes it difficult to purify the exhaust gas of the engine to a high degree.
To solve this-problem, the same application as in the present patent application proposed an air-fuel ratio detecting device in Japanese Patent Application No. 7-12325, which corrects an error in the output caused by the air-fuel ratio sensor and the air-fuel ratio sensor circuit and correctly and precisely detects the air-fuel ratio in the engine. This device is designed to take into consideration that a first output data from the air-fuel ratio sensor circuit when the air-fuel ratio sensor is inactive equals to a second output data from the air-fuel ratio sensor circuit corresponding to the stoichiometric air-fuel ratio when the air-fuel ratio sensor is active, and to correct the error of the output data from the air-fuel ratio sensor circuit when determining the air-fuel ratio in the engine after defining that the first output data is equals to the second output data, thereby obtaining the accurate air-fuel ratio.
However, in the device proposed by the Japanese Patent Application. No. 7-12325, whether or not the air-fuel ratio sensor is inactive is determined by water temperature of the engine. Therefore, it is possible to determine incorrectly when the water temperature of the engine does not match the temperature of a sensing element in the air-fuel ratio sensor and, as a result, it is possible that the device may incorrectly detect the above first output data corresponding to the stoichiometric air-fuel ratio.
SUMMARY OF THE INVENTION
The present invention has been made in view of the foregoing problems and it is therefore an object of the present invention to provide an air-fuel ratio detecting device and a method therefor which surely determines an inactive state of the air fuel ratio sensor and avoids incorrectly detecting the output data of the air-fuel ratio sensor circuit corresponding to the stoichiometric air-fuel ratio, thereby accurately and precisely detecting the air-fuel ratio in the engine.
FIG. 1 is a diagram showing the constitution of fundamental blocks according to the present invention. In FIG. 1, the part surrounded by broken lines is the air-fuel ratio detecting device of the present invention.
In order to accomplish the above object, an air-fuel ratio detecting device 1 for detecting the air-fuel ratio in an internal combustion engine 10 comprises a limiting current type air-fuel ratio sensor 20 and an air-fuel ratio sensor circuit 30 which detects the air-fuel ratio in the engine based on the output of the air-fuel ratio sensor circuit 30.
In the air-fuel ratio detecting device, the limiting current type air-fuel ratio sensor 20 is arranged in an exhaust system of the engine 10, generates an electric current when an electric voltage is applied thereto and is made from solid electrolyte, and the air-fuel ratio sensor circuit 30 applies the electric voltage to the sensor 20 within a range of the limiting current, detects the concurrent limiting current and outputs a signal proportional to the magnitude of the detected current.
The air-fuel ratio detecting device is characterized in that it comprises: a detecting means 40 for detecting a change in output voltage of the sensor circuit 30 when an applied voltage to the sensor 20 is changed from a voltage within the range of the limiting current to a voltage out of the range of the limiting current at a determined time after the engine 10 is started; a determining means 50 for determining whether the change in the output voltage of the sensor circuit 30 detected by the detecting means is less than a determined value or not; and a correcting means 60 for correcting the output error of the sensor circuit 30 corresponding to the air-fuel ratio based on the output voltage of the sensor circuit 30 when the determining means 50 determines that the output voltage change is less than the determined value.
The above air-fuel ratio detecting device 1 outputs a voltage corresponding to the air-fuel ratio in the engine 10 from the air-fuel ratio sensor circuit 30 connected to the limiting current type air-fuel ratio sensor 20 exposed to the exhaust gas of the engine 10. The correcting means 60 inputs the correct data corresponding to the air-fuel ratio in the engine 10 to a fuel injection amount controlling means 70 after correcting the output data from the sensor circuit 30. The fuel injection amount controlling means 70 calculates and supplies the fuel injection amount so that the air-fuel ratio in the engine 10 becomes a target ratio based on the data output from the correcting means 60.
In order to accomplish the above object, an air-fuel ratio detecting method for detecting the air-fuel ratio in an internal combustion engine 10 uses an air-fuel ratio detecting device 1 which comprises a limiting current type air-fuel ratio sensor 20 in real use and an air-fuel ratio sensor circuit 30 in real use, and detects the air-fuel ratio in the engine based on the output of the air-fuel ratio sensor circuit 30. In the air-fuel ratio detecting device, the limiting current type air-fuel ratio sensor 20 in real use is arranged in an exhaust system of the engine 10, generates an electric current when an electric voltage is applied thereto and is made from solid electrolyte. The air-fuel ratio sensor circuit 30 in real use applies the electric voltage to the sensor 20 within a range of the limiting current, detects the concurrent limiting current and outputs a signal proportional to the magnitude of the detected current.
The air-fuel ratio detecting method according to the present invention is characterized in that it comprises the steps of: detecting a change in output voltage of the sensor circuit 30 when an applied voltage to the sensor 20 is changed from a voltage within the range of the limiting current to a voltage out of the range of the limiting current at a determined time after the engine 10 is started; determining whether the change in the output voltage of the sensor circuit 30 detected in the first step is less than a determined value or not; reading a first output data of the sensor circuit 30 in real use when it is determined in the second step that the output voltage change is less than the determined value; reading a second output data of a reference sensor circuit corresponding to the stoichiometric air-fuel ratio from a previously created map with the use of a reference sensor and the reference sensor circuit, said map being made for calculating output data of the reference sensor circuit corresponding to the air-fuel ratio in the engine 10; correcting each output data of the sensor circuit 30 in real use after said determined time has passed from the engine start up based on an output error between the first output data and the second output data; and calculating each air-fuel ratio corresponding to the corrected output data corrected in the fifth step.
The mode of operation of the present invention will be explained below.
The detecting means changes an applied voltage to the sensor from a voltage within the range of the limiting current to a voltage out of the range of the limiting current at a predetermined time after the engine is started, and detects a change in output voltage of the sensor circuit. When the sensor element is warmed up, the determining means can surely determine whether or not the change in the output voltage of the sensor circuit is less than a determined value, namely, the inactive state of the sensor can be more accurately determined. The correcting means compares the output voltage of the sensor circuit at a time when the sensor is inactive as to the output voltage of the sensor circuit corresponding to the stoichiometric air-fuel ratio in the engine at a time when the sensor is active and, thereby, the output voltage of the sensor circuit corresponding to the stoichiometric air-fuel ratio can be accurately detected. The correcting means then corrects the error between a first output voltage of the sensor circuit in real use corresponding to an air-fuel ratio in the engine and a second output voltage of a reference air-fuel ratio sensor circuit corresponding to the same air-fuel ratio in the engine based on the output voltage of the sensor circuit in real use corresponding to the stoichiometric air-fuel ratio in the engine. The second output voltage is obtained when detecting the air-fuel ratio in the engine with the use of the reference air-fuel ratio sensor and the reference air-fuel ratio sensor circuit. Thus the air-fuel ratio in the engine is more accurately detected.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be more clearly understood from the description as set forth below with reference to the accompanying drawings, wherein:
FIG. 1 is a diagram showing the constitution of fundamental blocks according to the present invention;
FIG. 2 is a diagram illustrating an air-fuel ratio sensor circuit employed by an embodiment;
FIG. 3 is a diagram illustrating output waveforms of the air-fuel ratio sensor circuit immediately after the start of an engine;
FIG. 4 is a diagram illustrating characteristic curves of an air-fuel ratio sensor;
FIG. 5 is a diagram illustrating a conversion map of air-fuel ratios in an internal combustion engine corresponding to the outputs of an air-fuel ratio sensor circuit;
FIG. 6 is a flowchart showing a processing sequence of a routine for detecting an air-fuel ratio (A/F) according to the present invention;
FIG. 7 is a flowchart showing a processing sequence of a routine for calculating a cranking fuel injection period (TAUST) according to the present invention;
FIG. 8 is a flowchart showing a processing sequence of a routine for calculating a post-cranking fuel injection period (TAU) according to the present invention; and
FIG. 9 is a flowchart showing a processing sequence of a fuel injection control routine according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The preferred embodiments of the present invention will be described below with reference to the accompanying drawings.
FIG. 2 is a diagram, illustrating an air-fuel ratio sensor employed by an embodiment of the present invention. In FIG. 2, reference numerals R1 to R6 and R9 to R16 denote resistors, C1 and C2 denote capacitors, D1 to D4 denote diodes, Tr1 to Tr4 denote transistors, and OP1 to OP3 denote operational amplifiers. Constant voltages V1 and V2 are applied to the air-fuel ratio sensor circuit (hereinafter referred to as a sensor circuit), and a limiting current type air-fuel ratio sensor (hereinafter referred to as a sensor) that is not shown is connected between electrodes S+ and S- between the operational amplifiers OP1 and OP2 as shown in FIG. 2. Then, a constant voltage set by the operational amplifiers OP1 and OP2 is applied to the sensor connected across the above electrodes. The resistor R10 works to detect an electric current generated by the sensor. The voltage V1 is applied to drive the transistors Tr1 to Tr4, operational amplifiers OP1 to OP3, and the sensor. A voltage V2 is applied to provide a very precise reference voltage to the operational amplifier OP1. The voltage V2 is about 5 volts, so a voltage of 3.0 volts divided by the resistors R1 and R2 is input to the operational amplifier OP1.
A digital to analog converter DAC is provided between an input terminal IT and an input of the OP2. The input terminal IT is connected to an electronic control circuit ECU (not shown) which supplies the digital signal to the DAC. Output voltage V3 of the DAC is controlled by means of the ECU to become 2.8 volts at a time when the engine is started and 3.3 volts after a determined time has passed from the start of the engine, and is input to the operational amplifier OP2. Next, the output of the OP2 varies in response to a voltage applied to the sensor connected between the electrodes S+ and S- an air-fuel ratio in the exhaust gas of the engine. The output of the OP2 becomes equal to the voltage V3 when the sensor is inactive or when the air-fuel ratio in the exhaust gas of the engine is stoichiometric because the internal electric current of the sensor becomes 0 mA at this time. Next, the output of the OP2 is input to the operational amplifier OP3 that works as an integrating circuit, thus a stable voltage which does not transiently change is output from an output terminal OT of the sensor circuit in response to the air-fuel ratio in the engine. In the present invention, the electronic control unit ECU is, for example, made by a micro-processor system including a CPU, a RAM, a ROM, input/output interfaces and the like, and performs basic engine controls such as the fuel injection amount control, the ignition timing control and the like.
FIG. 3 is a diagram illustrating output waveforms of an air-fuel ratio sensor circuit shown in FIG. 2 immediately after the start of the engine, wherein the abscissa represents the time and the ordinate represents the output voltage of the sensor circuit. When the engine is, started at the moment t 0 , voltages are applied from a battery and the ECU to the sensor circuit and to the sensor, and the output voltage of the sensor circuit which is 0 volt at the moment t 0 , suddenly rises up to 2.8 volts which is same as the voltage V3 at the moment t 1 , that is, for example, two seconds after the moment t 0 because the voltage V3 shown in FIG. 2 is preset so as to become 2.8 volts at the start of the engine, namely, at the moment t 0 , by means of the ECU. The output of the sensor circuit suddenly rises up to 3.3 volts at the moment t 2 that is five seconds after the moment t 0 because the voltage V3 is preset so as to become 3.3 volts at the moment t 2 by means of the ECU. The output voltage of the sensor circuit remains constant at 3.3 volts as long as the sensor is in an inactive state. As the air-fuel ratio sensor becomes partially active, however, the output voltage fluctuates at a low frequency, with 3.3 volts as a center, as shown. Then, as the sensor becomes active at the moment t 3 that is ten seconds after the moment t 0 , the output voltage fluctuates at a high frequency with 3.3 volts as a center. As described earlier, the output current generated by the sensor becomes zero (0 mA) when the air-fuel ratio in the exhaust gas detected by the sensor is stoichiometric or when the sensor is in the inactive state. Therefore, the output voltage of the sensor circuit under these conditions becomes 2.8 volts at the engine start up time and 3.3 volts after the engine started up.
Next, an output of the operational amplifier OP2 will be explained below. The air-fuel ratio sensor comprising an electrolyte connected between the electrodes S+ and S- is arranged in the exhaust system of the engine, exposed to the exhaust gas from the engine, and the internal current of the sensor varies. The output of OP2 changes in response to changes of the current generated in the sensor. As long as a voltage, for example, 3.3 volts that is within the limiting current range is applied to the sensor, the sensor does not generate the internal current when the exhaust gas from the engine is stoichiometric or the sensor is inactive. Therefore, the air-fuel ratio detecting device proposed in the Japanese Patent Application No. 7-12325 determines that the sensor is inactive when the coolant of the engine is below 30 degrees (°C.), continually supplies 3.3 volts to the sensor when the engine is running, and corrects the output error of the sensor circuit after regarding an average output voltage of the sensor circuit for a determined period from the start of the engine as the stoichiometric voltage that is the output voltage of the sensor circuit when the sensor detects the stoichiometric air-fuel ratio in the exhaust gas from the engine.
However, the sensor is not always in an inactive state during a determined period of time from the engine start up but the sensor may be in a half-active state or an active state as shown in FIG. 3 even though the coolant temperature is below 30 degrees. For example, the sensor is in a half-active state or an active state during a period of time after the engine is restarted soon after a short stop of the engine although the coolant temperature is, for example, 25 degrees. In this case, if the output voltage of the sensor circuit is regarded as the stoichiometric voltage, the fluctuated output voltage of the sensor circuit at the time when the sensor is in a half-active state or the active state as shown in FIG. 3, is detected, so that an accurate stoichiometric voltage cannot be detected.
Hereinafter, characteristics of the air-fuel ratio sensor will be explained.
FIG. 4 is a diagram illustrating characteristic curves of an air-fuel ratio sensor which are different depending on air-fuel ratios. In FIG. 4, the abscissa represents the supply voltage to an air-fuel ratio sensor and the ordinate represents the current generated by the sensor. In FIG. 4, a thick solid direct line A represents a characteristic curve of an air-fuel ratio sensor when the temperature of the sensor element is about 400 degrees, that is an inactive state, while other characteristic curves represent when the temperature of the sensor element is about 700 degrees, that is an active state. From FIG. 4, it can be understood that the internal current of the sensor is 0 mA when the air-fuel ratio to be detected by the sensor is stoichiometric, namely, about 14.5 and that the current linearly changes in response to the changes of the air-fuel ratio, under the conditions that the power supply to the sensor is, for example, 0.3 volts which is in the limiting current range and when the sensor is in an active state in which temperature of the sensor element is 700 degrees. On the other hand, it can be understood that the internal current of the sensor is constant at 0 mA as indicated A in FIG. 4 when the sensor is in an inactive state in which the temperature of the sensor element is 400 degrees, and is about -15 mA when the sensor is in an active state in which the temperature of the sensor element is 700 degrees, regardless the changes in the air-fuel ratio, under the conditions that the power supply to the sensor is, for example, -0.2 volts which is out of the limiting current range.
If this phenomena are applied to determine the sensor's inactive state, more accurate determination of the sensor's inactive state can be realized as comparing with determination by the coolant temperature of the engine. By the way, -0.2 volts power supply to the sensor can be realized by setting 2.8 volts at V3 in FIG. 2, while 0.3 volts power supply to the sensor can be realized by setting 3.3 volts at V3. Therefore, the ECU transmits digital signals to the input terminal ITP of the sensor circuit such that the input voltage V3 to the operational amplifier OP2 is set to 2.8 volts at the start of the engine and 3.3 volts after a determined time has passed from the start of the engine, as explained before. The output voltage of the OP2 becomes 2.8 volts at the start of the engine and 3.3 volts after a determined time has passed from the start of the engine because the current generated from the sensor is 0 mA when the sensor detects the stoichiometric air-fuel ratio in the exhaust gas or when the sensor is inactive. However, the sensor generates about -15 mA and both outputs, OP2 and OP3, become about 2.0 volts when the sensor is in inactive state even though 2.8 volts is applied to the sensor at the start of the engine. It should be understood that more accurate determination of the sensor's active state can be realized by determining it based on the changes of the output voltages of the OP2 and OP3 than by determining it based on the coolant temperature of the engine.
FIG. 5 is a diagram illustrating a conversion map of the air-fuel ratios in an engine corresponding to the outputs of the air-fuel ratio sensor circuit. In FIG. 5, the abscissa represents the air-fuel ratio ABF in the engine detected by the air-fuel ratio sensor and the ordinate represents the output voltage VAF of the sensor circuit. In FIG. 5, a thick solid line represents a characteristic curve of the conversion map found in advance, by bench testing, in order to calculate the air-fuel ratios in the engine corresponding to the outputs of the sensor circuit. The data for forming the conversion map are measured in advance, by bench testing, by using a reference air-fuel ratio sensor and a reference air-fuel ratio sensor circuit, and are stored in the storage circuit RAM. In FIG. 5, broken lines represent a characteristic curve of an air-fuel ratio sensor circuit used in a real engine and formed in a manner as described below. The characteristic curve shown in FIG. 5 is somewhat exaggerated to ease understanding. First, a point S is plotted at which the output voltage VAF of the sensor circuit equals to a stoichiometric voltage VAFS that is measured by using the sensor and the sensor circuit that are mounted on the real engine and the air-fuel ratio is stoichiometric, i.e., 14.5.
Next, a procedure to calculate the stoichiometric voltage VAFS will be explained. As explained before, when a digital signal is transmitted to the input terminal IT of the sensor circuit from the ECU such that the power supply to the sensor becomes -0.2 volts, namely, the input voltage V3 to the OP2 in the sensor circuit becomes 2.8 volts for five seconds after the start of the engine, the output voltage of the sensor circuit remains almost constant, about 2.8 volts, as long as the sensor is inactive. Thus, the stoichiometric voltage VAFS can be obtained by reading the output voltage of the sensor circuit at this time, and adding 0.5 volts to the read data because the current generated from the sensor is 0 mA regardless of the detected air-fuel ratio as long as the sensor is in an inactive state when a voltage out of the limiting current, in the case of this embodiment, -0.2 volts, is applied to the sensor.
Next, the point MS corresponding to the stoichiometric air-fuel ratio is plotted on a characteristic curve of a conversion map indicated by a solid line as shown in FIG. 5, and an output voltage VAFMS of the sensor circuit corresponding to the point MS is read. Then, a plurality of points on the characteristic curve of the conversion map are shifted and plotted in the direction of the axis of ordinate with the distance of VAFS-VAFMS, and a new characteristic curve of the conversion map for real use is created by connecting these plotted points with broken lines. The output voltage VAF of the sensor circuit corresponding to an air-fuel ratio, measured in the real engine, approximately coincides with the output voltage corresponding to the same air-fuel ratio, read from the newly created characteristic curve shown by the broken lines. Therefore, an accurate air-fuel ratio in the engine can be calculated by executing the steps of reading output voltage VAF of the sensor circuit, calculating the equation VAF-(VAFS-VAFMS), updating VAF by the results of the calculation VAF-(VAFS-VAFMS), and reading the air-fuel ratio corresponding to a point for the updated VAF on the characteristic curve originally made by bench testing.
FIG. 6 is a flowchart showing a processing sequence of a routine for detecting an air-fuel ratio (A/F) according to the present invention. This flowchart shows a routine that accurately detects the air-fuel ratio (A/F) according to the present invention with the use of an air-fuel ratio sensor and an air-fuel ratio sensor circuit carried on a real automobile. This routine is executed every predetermined number of degrees in the crank angle of the engine, for example, every 180 degrees in crank angle (180° CA) or every predetermined period of time, for example, every 100 msec. The detecting means, the determining means and the compensating means of the present invention are carried out by executing processes of steps 601 to 619, a step 621 and steps 623 to 649 respectively. The flowchart shown in FIG. 6 will be explained in detail below.
First in step 601, it is determined whether or not the ignition switch is changed over from off to on. If it is determined yes, the processing cycle of the routine proceeds to step 603, if it is determined no, the cycle proceeds to step 605. In the step 603, a preset start flag STFLG and a timer T are reset, and the cycle proceeds to the step 605. In the step 605, it is determined whether or not the engine is started. This is determined by whether or not the number of revolutions NE of the engine exceeds 400 RPM (revolution per minute). If the number NE is equal or more than 400 RPM (NE≧400), it is determined that the engine is started and the cycle proceeds to step 607, if the number NE is less than 400 RPM (NE<400), the cycle ends. In the step 607, it is determined whether or not conditions for the air-fuel ratio feedback control of the engine are met. If the result is yes, the cycle proceeds to step 641, if the result is no, the cycle proceeds to step 611. It is determined that the above conditions are met if all the following conditions (1) to (4) are met.
(1) The engine is not in the start-up time. (T>5 sec)
(2) The fuel cut control is not being executed.
(3) The coolant temperature THW of the engine is equal to or greater than 40° C. (THW≧40° C.).
(4) The air-fuel ratio sensor is active.
Next, in the step 611, a digital signal is transmitted from the ECU to the D/A converter in the air-fuel ratio sensor circuit so that the voltage V3 shown in FIG. 2 is set 2.8 volts. In step 613, it is determined whether or not a determined time t 2 , for example, 5 seconds or more has passed, from the start-up of the engine, if the result is yes, the cycle proceeds to step 641, if the result is no, the cycle proceeds to step 615. In the step 615, the current output voltage VAF of the sensor circuit is read, and the difference .increment.VAF.sub.(K) between an output voltage VAF.sub.(k-1) of the previous processing cycle and an output voltage VAF.sub.(k) of the current processing cycle is calculated in accordance with the equation .increment.VAF.sub.(K) =VAF.sub.(k) --VAF.sub.(k-1), and the cycle proceeds to step 617. In the step 617, the current output voltage VAF.sub.(K) read in the step 615 is replaced as the previous output voltage VAF.sub.(K-1) for the use in the next processing cycle.
Next, in step 619, it is determined whether the current output voltage VAF.sub.(K) is equal to or greater than a value of (V G1 --A) wherein V G1 is a learned value of the air-fuel ratio when the air-fuel ratio sensor is in an inactive state and A is a predetermined value, for example, 0.1 volt. If the result in the step 619 is yes, the cycle proceeds to step 621, if the result is no, the cycle ends. As shown in FIG. 3, the output voltage VAF of the sensor circuit increases when the engine is started at t 0 and saturates at t 1 up to the voltage of 2.8 volts equal to the voltage of V3. Therefore, in the step 619, it is determined whether the output voltage VAF of the sensor circuit has saturated or not at t 1 , after the engine is started. Next, in step 621, it is determined whether the output voltage VAF of the sensor circuit is changed or not in response to a change in state of the air-fuel ratio sensor from inactive to active. This is determined by whether or not .increment.VAF.sub.(K) calculated in the step 615 is within a predetermined value. That is, if |.increment.VAF.sub.(K) |<B, the cycle proceeds to step 623 because it is determined that the air-fuel ratio sensor is in an inactive state resulting from no change in the output voltage of the air-fuel ratio sensor circuit in response to the change in state in the sensor from inactive to active. If |.increment.VAF.sub.(K) |≧B, the cycle ends because it is determined that the air-fuel ratio sensor is in an active state. In this embodiment, B is set, for example, 0.02 volts.
Next, in the step 623, it is determined whether or not the start flag STFLG is 0, if the result is yes, the cycle proceeds to step 625, if the result is no, the cycle ends. Next, in the step 625, the start flag is set to 1. Accordingly, processes in the steps 625 to 631 are executed in only the first cycle after the engine is started, but are not executed from the second cycle after the engine is started and the cycle ends because the result in the step 623 is no. Next, in step 627, the learned value V G1 of the inactive air-fuel ratio is replaced by executing the following calculation.
V.sub.G1 ←V.sub.G1 +C(VAF.sub.(K) --V.sub.G1)tm
Wherein, C is a moving averaging constant of which value is, for example, 1/16. As can be understood, the learned value V G1 is given by deducting the learned value V G1 in the previous processing cycle from the output voltage VAF.sub.(K) of the sensor circuit read in the current processing cycle, multiplying the moving averaging constant C by the result of the reduction and adding the learned value V G1 to the result of the multiplication, and by replacing the learned value V G1 with the result of the calculation. The learned value V G1 of the inactive state air-fuel ratio and the learned value V G2 of the stoichiometric air-fuel ratio are preset to 2.8 and 3.3 volts, respectively, when shipping automobiles equipped with the air-fuel ratio detecting device according to the present invention. Next, in step 629, the learned value V G2 of the stoichiometric air-fuel ratio with the use of the air-fuel ratio sensor and the sensor circuit carried on a real automobile is calculated by the following calculation.
V.sub.G2 ←V.sub.G1 +0 5
Next, in step 631, the flag FBFLG that indicates whether or not the conditions for the air-fuel ratio feedback control of the engine are met is reset to 0 and the cycle ends.
On the other hand, if it is determined that conditions for the air-fuel ratio feedback control of the engine are met in the step 607, or if it is determined that five seconds or more has passed after the engine is started in the step 613, the cycle proceeds to the step 641 and a digital signal is transmitted to the D/A converter in the sensor circuit from the ECU so as to set the voltage of V3 shown in FIG. 2 at 3.3 volts. Next, in step 643, it is determined whether or not a predetermined time t 3 , for example, ten seconds or more, has passed since the engine started. If the result is yes, the cycle proceeds to step 645, the flag FBFLG is set to 1 and the cycle ends. If the result is no, the cycle proceeds to step 631, the flag FBFLG is reset to 0 and the cycle ends.
Next, in step 647, the output voltage VAF of the sensor circuit used for the real automobile is calibrated in accordance with the following equation:
VAF=VAF.sub.K) --(VAFS--VAFMS)
based upon (1) the learned value V G2 for stoichiometric air-fuel ratio obtained by executing the step 629, namely, the stoichiometric voltage VAFS, (2) the output voltage VAFMS of the reference air-fuel ratio sensor circuit corresponding to, for example, the stoichiometric air-fuel ratio 14.5 on the conversion map that has been made in advance by the bench test with the use of the reference air-fuel ratio sensor and the reference air-fuel ratio sensor circuit, and (3) the output voltage VAF.sub.(K) of the air-fuel ratio sensor circuit detected in this processing cycle, and the cycle then proceeds to step 649.
In the step 649, the air-fuel ratio in the engine corresponding to the output voltage VAF of the air-fuel ratio sensor circuit obtained by the calibration in the step 647 is calculated, i.e., the air-fuel ratio after correction is calculated based on the conversion map that has been formed in advance and stored in a storage circuit such as a RAM. This corresponds to finding a point on a characteristic curve represented by broken lines shown in FIG. 5 by shifting a point on the characteristic curve of the conversion map formed in advance by the bench test represented by a solid line shown in FIG. 5 in the direction of the axis of ordinate with the distance of VAFS--VAFMS corresponding to an output voltage VAF.sub.(K) of the air-fuel ratio sensor circuit detected at this processing cycle. Hereinafter, the fuel injection amount controlling means of the present invention will be described.
FIG. 7 is a flowchart showing a processing sequence of a routine for calculating a cranking fuel injection period (TAUST) according to the present invention. This routine is executed in a main routine of the EUC. In step 701, the coolant temperature THW of the engine is read from a coolant temperature sensor arranged in a water jacket of the engine block. In step 702, a basic fuel injection period TAUSTB is calculated from a map stored in the ROM based on the coolant temperature THW read in the step 702. In step 703, the number of revolutions NE of the engine is read from the crank angle sensor and the battery voltage BA is read via an A/D converter (not shown). In step 704, the correction coefficients KNETAU and NBATAU are calculated from maps stored in the ROM based on the number of revolutions NE of the engine and the battery voltage BA both read in the step 702. In step 705, an ineffective fuel injection period Ts is calculated from a map stored in the ROM based on the battery voltage read in the step 702. In step 706, the post-cranking fuel injection period TAUST is calculated in accordance with the following equation based on the basic fuel injection period TAUSTB, the correction coefficients KNETAU and NBATAU and the ineffective fuel injection period Ts, each obtained in the steps 702, 704 and 705.
TAUST=TAUSTB*KNETAU*NBATAU+Ts(msec)
FIG. 8 is a flowchart showing a processing sequence of a routine for calculating a post-cranking fuel injection period (TAU) according to the present invention. In step 801, different kinds of signals are read as input data. In step 802, the basic fuel injection period TP corresponding to the engine operational condition is calculated from a two dimensional map stored in the ROM based on the number of revolutions NE and the intake air pressure PM of the engine read in the step 801. In step 803, a correction coefficient a is calculated based on the coolant temperature THW, the throttle opening TA, the intake air temperature THA and etc.. Next, in step 804, the ineffective fuel injection period Ts is calculated from a map stored in the ROM based on the battery voltage BA. In step 805, the air-fuel ratio correction coefficient DAF is calculated from the difference between the air-fuel ratio in the engine calculated in the step 649 in the flowchart shown in FIG. 6 and a target air-fuel ratio, for example, the stoichiometric air-fuel ratio in this embodiment such that the correction coefficient DAF is decreased when the air-fuel ratio in the engine is rich, while it is increased when the air-fuel ratio in the engine is lean. The air-fuel ratio correction coefficient DAF is calculated in response to the output value of the air-fuel ratio sensor circuit in such a way that DAF=1.0 when an increase or a decrease correction is not made, 0.8<DAF<1.0 when a decrease correction is made, and 1.0<DAF<1.2 when an increase correction is made. This air-fuel ratio correction coefficient DAF is a feedback correction coefficient to control the air-fuel ratio in the engine to be a stoichiometric. In step 806, the post-cranking fuel injection period TAU is calculated in accordance with the following equation based on the basic fuel injection period TP, the correction coefficient a, the ineffective fuel injection period Ts and the air-fuel ratio correction coefficient DAF, in the steps of 802, 803, 804 and 805 respectively.
TAU=TP*α(DAF+β)+Ts
Wherein βis another coefficient different from DAF.
FIG. 9 is a flowchart showing a processing sequence of a fuel injection control routine according to the present invention. The fuel injection means of the present invention is carried out by executing processes in the flowchart shown in FIG. 9. This fuel injection routine is executed for each cylinder every 30 degrees in crank angle (30° CA) at the time when the 30° CA sensor outputs the signal to the ECU. This 30° CA interrupt routine starts when the ignition switch is turned on and ends when the ignition switch is turned off. First, in step 901, it is determined whether or not it is the timing for fuel injection from the crank angle sensor signal. If the result is yes, the cycle proceeds to step 903, if the result is no, the cycle ends. In the step 903, it is determined whether or not the previously set flag FBFLG is 0 (indicating the conditions are not met) by executing the air-fuel ratio detecting routine explained with reference to FIG. 6, wherein the flag FBFLG=1 indicates that conditions for the air-fuel ratio feedback control of the engine are met. If the result is yes, the cycle proceeds to step 905, if the result is no, the cycle proceeds to step 907. In the step 905, the cranking fuel injection period TAUST of the engine as explained with reference to FIG. 7 is set as the current fuel injection period tTAU. In the step 907, the post-cranking fuel injection period TAU of the engine as explained with reference to FIG. 8 is set as the current fuel injection period tTAU. Next, in step 909, the fuel injection valves are opened to inject the fuel toward the cylinders of the engine in accordance with the fuel injection period tTAU calculated in the step 905 or 907.
As heretofore explained, according to the air-fuel ratio detecting device and the method of the present invention, the air-fuel ratio can be accurately detected and the exhaust gas of the engine can be more purified by controlling the amount of the fuel injection based on the air-fuel ratio detected by the air-fuel ratio detecting device.
It will be understood by those skilled in the art that the foregoing description is a preferred embodiment of the disclosed device and that various changes and modifications may be made in the invention without departing from the spirit and scope thereof.
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A device for detecting the air-fuel ratio in an engine comprises a limiting current type air-fuel ratio sensor 20, an air-fuel ratio sensor circuit 30, a detecting means 40, a determining means 50 and a correcting means 60. The air-fuel ratio sensor 20, which is arranged in an exhaust system of the engine 10, generates an electric current when a voltage is applied thereto and is made from solid electrolyte. The sensor circuit 30 applies a voltage to the sensor 20 within a range of the limiting current, detects a concurrent limiting current and outputs a signal proportional to the magnitude of the detected current. The detecting means 40 detects a change in the voltage output from the sensor circuit 30 when the voltage applied to the sensor 20 is changed from a voltage within the range of the limiting current to a voltage outside the range of the limiting current a predetermined time after the engine 10 is started. The determining means 50 determines whether the change in output voltage of the sensor circuit 30 is less than a predetermined and correcting means 60 corrects an output error of the sensor circuit 30 based on the voltage output from the sensor circuit 30 when it is determined that the output voltage change is less than the predetermined value.
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This claims the benefit to U.S. Provisional Patent Application No. 61/898,943, filed on Nov. 1, 2013, which is hereby incorporated by reference herein.
The present disclosure relates generally to clutch assemblies for motor vehicle transmissions and more particularly to release springs for pistons in clutch assemblies.
BACKGROUND
U.S. Pat. No. 6,095,941 discloses a clutch assembly including a release spring retained by a snap ring.
SUMMARY OF THE INVENTION
A clutch assembly for a motor vehicle drive train is provided. The clutch assembly includes a clutch pack; a piston for engaging the clutch pack; a housing including a surface for slidably supporting the piston; a release spring for disengaging the piston from the clutch; and a bearing supporting the clutch pack. The bearing limiting axial movement of the release spring away from the piston.
A method of assembling a clutch assembly for a motor vehicle drive train is also provided. The method includes sliding a piston onto a surface of a housing; sliding a retainer spring against the piston; and sliding an inner race of a bearing onto the housing such that the inner race of the bearing limits axial movement of the release spring away from the piston.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is described below by reference to the following drawings, in which:
FIG. 1 shows a clutch assembly for a transmission in a motor vehicle drive train in accordance with a first embodiment of the present invention; and
FIG. 2 shows a clutch assembly for a transmission in a motor vehicle drive train in accordance with a second embodiment of the present invention.
DETAILED DESCRIPTION
The present disclosure provides a one-way clutch inner race used as a reaction point for a clutch pack release spring. In the embodiments discussed below, the outer race serves as a clutch carrier for a series of clutch plates. The piston is released by a release spring acting between the piston and the inner race.
FIG. 1 shows a clutch assembly 10 for a transmission in a motor vehicle drive train in accordance with a first embodiment of the present invention. Clutch assembly 10 includes a clutch pack 11 formed by a plurality of clutch plates 12 including friction surfaces 14 on both sides thereof that are axially slidable along an outer radial surface of a bearing 18 and a plurality of clutch plates 20 that are axially slidable along an outer support 22 of a housing 24 . An axially slidable piston 26 is forced toward and away from the end clutch plate 20 to engage and disengage clutch pack 11 with an axial extension 27 thereof. In order to engage clutch pack 11 , a force exerted on piston 26 in the direction of clutch pack 11 needs to overcome a force exerted by a return spring 28 onto piston 26 . Return spring 28 is positioned radially inside of axial extension 27 and contacts piston 26 with a radially outer portion 30 thereof. An inner radial end 32 of return spring 28 is held axially in place by a snap ring 34 , which contacts return spring 28 on a side of return spring 28 opposite of a side return spring 28 that contacts piston 26 .
Snap ring 34 includes an inner radially extending portion 36 and an outer radially extending portion 38 that are axially offset from each other by an axially extending portion 40 connecting radially extending portions 36 , 38 . Outer radially extending portion 38 is arranged axially further away from bearing 18 than inner radially extending portion 36 and contacts inner radial end 32 of return spring 28 . In contrast to U.S. Pat. No. 6,095,941, snap ring 34 is not machined into housing 24 . Instead, snap ring 34 is sandwich axially between a radially extending surface 68 of an axially protruding lip 44 of housing 24 and a radially extending surface 66 of inner race 56 that aligns with a radially extending surface 68 . Axially protruding lip 44 hangs over an annularly shaped blind hole 46 formed by an inner radial surface 48 of lip 44 , an axial stop 50 and a first radial support surface 52 of housing 24 . Housing 24 also includes a second radial support surface 54 radially outside of the axially protruding lip 44 , which piston 26 slides axially along during engagement and disengagement of clutch pack 11 .
Bearing 18 is supported by first radial support surface 52 and includes an inner race 56 contacting first radial support surface 52 , a rolling element 58 riding along inner race 56 and an outer race 60 radially outside of rolling bearing 58 that includes a splined surface for receiving clutch plates 12 . Bearing 18 , at inner race 56 , includes an axial protrusion 62 received radially inside of axially protruding lip 44 and contacting axial stop 50 . Protrusion 62 includes an outer radial surface 64 aligned with inner radial surface 48 of lip 44 that extends axially from a radial extending surface 66 of inner race 56 that aligns with a radially extending surface 68 of lip 44 .
To assemble clutch assembly 10 , piston 26 is first slid onto second radial support surface 54 , then retainer spring 28 is slid against piston 26 . Next, snap ring 34 is slid onto housing 24 such that inner radially extending portion 36 contacts a radially extending surface 68 of lip 44 and inner race 56 , either alone or with rolling element 58 and possibly outer race 60 , is slid onto first radial support surface 52 of housing 24 such that protrusion 62 is received radially inside of axially protruding lip 44 and contacts axial stop 50 and radially extending surface 66 of inner race 56 contacts snap ring 34 at inner radially extending portion 36 to fix return spring 28 and snap ring 34 in place.
FIG. 2 shows a clutch assembly 110 for a transmission in a motor vehicle drive train in accordance with a third embodiment of the present invention. Clutch assembly 110 is formed in substantially the same manner as clutch assembly 10 , with the only differences being the constructions of housing 124 , the elimination of snap ring 34 and replacing return spring 28 with a longer return spring 128 . In this embodiment, because snap ring 34 is not used for retaining return spring 128 , housing 124 , like housing 24 from the first embodiment, does not include an annular groove machined therein. Additionally, axially protruding lip 44 is replaced by a more compact axially protruding lip 124 that is spaced away from radially extending surface 66 . Instead of using the housing to help retain return spring 128 , return spring 128 is retained directly by inner race 56 . Inner race 56 is fixed in place on a first support surface 152 of housing such that inner race 56 directly contacts inner radial end 132 of return spring 128 . Radially extending surface 66 of inner race 56 forms an axial stop contacting release spring 128 to limit the axial movement of release spring 128 away from piston 26 .
Axially protruding lip 144 hangs over an annularly shaped blind hole 146 formed by an inner radial surface 148 of lip 144 , an axial stop 150 and first radial support surface 152 of housing 124 . Housing 124 also includes a second radial support surface 154 radially outside of the axially protruding lip 144 , which piston 26 slides axially along during engagement and disengagement of clutch pack 11 .
To assemble clutch assembly 110 , piston 26 is first slid onto second radial support surface 154 , then retainer spring 128 is slid against piston 26 . Next, inner race 56 , either alone or with rolling element 58 and possibly outer race 60 , is slid onto first radial support surface 152 of housing 124 such that an end of protrusion 62 is received radially inside of axially protruding lip 144 and contacts axial stop 150 and radially extending surface 66 of inner race 56 directly contacts inner radial end 132 of return spring 128 to fixed return spring 128 in place.
In comparison with a clutch assembly having an annular groove machined into the housing, clutch assemblies 10 , 110 may be advantageous in that the elimination groove 42 and snap ring 34 saves cost.
In the preceding specification, the invention has been described with reference to specific exemplary embodiments and examples thereof. It will, however, be evident that various modifications and changes may be made thereto without departing from the broader spirit and scope of invention as set forth in the claims that follow. The specification and drawings are accordingly to be regarded in an illustrative manner rather than a restrictive sense.
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A clutch assembly for a motor vehicle drive train is provided. The clutch assembly includes a clutch pack; a piston for engaging the clutch pack; a housing including a surface for slidably supporting the piston; a release spring for disengaging the piston from the clutch; and a bearing supporting the clutch pack. The bearing limiting axial movement of the release spring away from the piston. A method of assembling a clutch assembly is also provided.
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CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority to U.S. Provisional Application No. 61/563,352 filed Nov. 23, 2011. The entire disclosure of the above-referenced application is incorporated herein by reference in its entirety.
TECHNICAL FIELD
The present subject matter relates generally to a movable highlight strip that can be used, for example, with a notebook.
BACKGROUND
Known office supplies include a number of marking, flagging, and/or highlighting products. For example, tabbed partitions (e.g., dividers inserted between sets of pages with tabs protruding from the pages), such as those described in U.S. patent application No. 2003/0178837 and U.S. Pat. Nos. 1,614,838 and 4,970,984, provide a way for users to mark certain pages or sections for ease of reference. Flags with an even greater customizable placement, such as those described in U.S. Pat. Nos. 4,637,149, 4,898,115, and 5,283,091, provide a way for users to mark specific locations, lines, and/or words. The '091 patent describes the well known “sign here” flag, with a temporary adhesive for temporary use and subsequent removal.
Known office supplies also include translucent colored ink marking pens or “highlighters,” which can mark existing indicia and the surrounding area with a colored coating, leaving the indicia legible and emphasized. Highlighters are very common office tools, but suffer from a number of drawbacks, such as seepage to the other side of a page and/or onto the next page. Highlighter pens are also permanent, which can be a desired attribute in some contexts, but is often another drawback. U.S. Pat. No. 4,175,777 discloses transparent colored sheets that can be affixed to cover subject matter desired to be marked or highlighted and extend to the margin of the page to be visible when the book is closed. The strips in this patent are provided individually, each on a release backing of a larger size.
It is desirable to provide an improved highlighter arrangement.
SUMMARY
A movable highlighting system that can include a base portion having a first surface that includes: a principal area of at least 80% of the base portion; and a marginal area. The system can include a binding or fastening member configured for holding a stack of paper on the principal area, and a supply of stickers in the marginal area. The stickers can include an adhesive configured to adhere to the paper in the stack. The stickers can include a plurality of highlighter strips that have a uniform translucent color configured for legibly highlighting indicia on the paper when adhered thereover. The adhesive can be disposed on a center portion of each strip, with one or both longitudinal ends of the strip being free of adhesive for permitting the end to be lifted from an adjacent sticker in the supply to which it is adhered.
The adhesive stickers can be stacked and releasably adhered to each other in the marginal area, which can be located on a side opposite the binding member. The base portion can be made from a cardboard sheet affixed to the stack by the binding portion that includes a binding on an upper edge. The paper can include marking areas, and can be ruled (e.g., with guidelines) of any number of standard or non-standard spacings. Each highlighter strip can be the same or proportional size of the rule spacing.
The base can include an attached flap, which can act as a bookmark or divider, and can include a plurality of the highlighter strips attached. The strips can also be configured in a roll, e.g., a dispensing roll, configured to dispense strips one at a time.
BRIEF DESCRIPTION OF DRAWINGS
The drawing figures depict one or more implementations in accord with the present concepts, by way of example only, not by way of limitations, In the figures, like reference numerals refer to the same or similar elements.
FIG. 1 is a view of a notepad with included highlighter strips, according to an exemplary embodiment of the present disclosure;
FIG. 2 is a side view of a single highlighter strip;
FIG. 3 is another notepad with pages flipped and strips affixed;
FIG. 4 is another notepad with a flap affixed to it, according to another exemplary embodiment of the present disclosure;
FIG. 5 is another view of FIG. 4 , with the flap in an opened position;
FIG. 6 is another view of FIGS. 4 and 5 , with the flap positioned as a page divider;
FIG. 7 is a stack of highlighter strips, according to another exemplary embodiment of the present disclosure;
FIG. 8 is a roll of highlighter strips, according to another exemplary embodiment of the present disclosure;
FIG. 9 is a ring-binder with included highlighter strips, according to another exemplary embodiment of the present disclosure;
FIG. 10 is a single highlighter strip, according to another exemplary embodiment of the present disclosure.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Exemplary embodiment can include various devices designed for receiving writing, such as a notepad, journal, or three-ring binder, etc. Referring to FIG. 1 , an exemplary embodiment is illustrated as a notepad 100 , including a base portion 110 , such as the cardboard backing of the notepad 100 . Base portion 110 can include a principle area 112 , and a marginal area 114 . These may be uniform portions of base portion 110 , or may be divided, e.g., by different material, appearance, texture, etc. Marginal area 114 is preferably smaller and longitudinally shorter than principle area 112 , and more preferably marginal area 114 will have up to about 20% of the area of base portion 110 and/or have a length 115 of up to about 20% of the length 117 of the base portion 110 , and in other embodiments below about 10%, 5%, or 3%. Preferably, the marginal area 114 will have at least about 3% of the area of base portion 110 and/or have a length 115 of at least about 3% of the length 117 of the base portion 110 . Marginal area 114 can be in any location, preferably on an edge, more preferably on an edge without binding (e.g., 118 ), and more preferably on an edge opposite a binding.
The exemplary notepad 100 of the exemplary embodiment illustrated in FIG. 1 , can include a binding member, such as exemplary binding 118 . This binding member 118 can be configured to hold a stack of paper 120 on the principle area 112 , and typically is provided as a notepad binding arrangement, which can include glue, staples, thread, clamps, etc., or any. combination of suitable binding arrangements. The binding 118 preferably has an end cover layer 121 that is wrapped around the top and longitudinal edge of the stack 120 and bottom of the base portion 110 to cover the longitudinal end portion of the notepad 100 and the staples 123 or other binding components. In this way, base portion 110 can include a common dimension (e.g., width) as paper 120 , while having a larger dimension (e.g., length) exposing marginal area 114 . The exemplary embodiment shown in FIG. 1 , e.g., as a notepad, can include sheets of paper 120 permanently bound by staples 123 . Paper 120 can be permanently fixed to backing 110 , or can include a perforation line 122 , which can allow pages to be removed from the fixed binding 118 . Whether fully attached or attached via a weakened perforation line 122 , pages can be flipped over the binding to access subsequent pages without removing previous pages (e.g., as shown in FIG. 2 ).
The exemplary embodiment illustrated in FIG. 1 , can include a supply of stickers 125 , 137 in the marginal area 114 . These stickers 125 can include an adhesive configured to form a releasable or permanent bond with paper in the stack 120 . The stickers 125 can be in any number of shapes, including the illustrated strip shape, and may be referred to in this and other exemplary embodiments as stickers or strips 125 . The adhesive can be included as a layer over part or all of each sticker 125 . FIG. 2 illustrates stickers 125 with an adhesive 129 provided on the underside of each sticker in a middle area 128 thereof, e.g., spanning between two end areas 126 , which are free of adhesive, for example to facilitate grabbing and removing of a sticker from either lateral side thereof. Any of the exemplary strips can include adhesive in any area, unless otherwise specified for those specific embodiments. For example, FIG. 2 illustrates an adhesive over a central portion 128 , which generally covers a centered portion of some fractional length, but could easily be included off-center (e.g., over portion 128 and the right end 126 , but not the left end 126 , etc. and vice versa), be included in non-continuous patches/sections, in patterns, or other partially covered arrangements. The adhesive region of sticker 125 can include any minimum area of adhesion, such as 1% of the overall area, but preferably can include over 50% of the area. The one or more adhesive free ends 126 can together or individually include any proportion of the total area (e.g., 1%), but preferably include about 10 to 20 percent each, or about 15% each. Thus, the adhesive to adhesive-free ratio can be any relative ratio, including about 9:1, 8:1, 7:1, 6:1, half-and-half or any ratio there between. These ratios can refer to the area of a single side, and the other side of strip 125 can preferably be free of adhesive on all or most of the surface, preferably all of the upper surface is free of adhesive.
In FIG. 1 , the lateral edges of the adhesive in middle area 128 is shown with hidden lines. The stickers 125 in the supply shown are releasably adhered to each other, to remain in a stack, and the bottom sticker 125 is adhered, preferably releasably to the base portion 110 . The base portion 110 can be provided with a release layer. The release layer can include wax, plastic, or any other material cooperatively selected to form a releasable bond with adhesive layer 129 . A release layer can be affixed to a substrate, sprayed onto the substrate, or be integrally formed from the material of the substrate.
FIG. 1 also illustrates strips 125 as including attached flags 137 . Each flag 137 can be translucent like strip 125 , discussed below, or opaque. Whether translucent or opaque, the flag 137 can be the same or different color as strip 125 . Flag 137 can be detachable or permanently connected. Further, flag 137 can include an adhesive like central portion 128 , or be free of adhesive like end portion 126 . The exemplary strip of FIG. 1 can be configured to be affixed at a page edge, such that flag 137 remains off the edge to act as an outside marker of a highlighted section, visible when the marked section is otherwise covered (e.g., the notepad/book is closed). In other exemplary embodiments, all of strip can include a layer of adhesive, including central portion, end portion, and optional second end portion, while flag 137 facilitates removal and grabbing by being free or partially free of adhesive. Flag 137 can be configured to receive writing, e.g., on its outer surface. Flag 137 can include adhesive on all or part of its under surface, for highlighting or flagging additional sections of indicia (e.g., by being detached from strip 124 ).
Each of the stickers 125 can have a translucent color, such that when placed over indicia (e.g., 65 ), the indicia remains legible through the sticker and any included adhesive (as shown by sticker 60 ). The translucent color is preferably uniform so to have the appearance of highlighter ink when placed on the paper over writing. Alternatively, the color and shading of the stickers can be varied or patterned. Further, the translucent color can span the entire strip 125 , or alternatively just the center portion 128 , just the ends 126 , or other combinations. Various colors or textures can be provided for each element or different parts of each sticker. Additionally, in the preferred embodiment, the stickers 125 are free of any printing or markings, such as lines or preprinted words, so that they resemble a line of highlighting when stuck to the paper, although alternative embodiments can have printed matter thereon for other purposes. Not only can the indicia remain legible, but the translucent color can highlight that indicia, flagging it among other indicia.
FIG. 1 also illustrates exemplary page 120 that includes ruling or guidelines. The ruling (e.g., the guidelines) can include the evenly spaced lines 142 , and/or margin line 143 , which may be printed on either side or both sides. The ruling can also include evenly spaced vertical lines (not shown), e.g., as in common graph paper. The ruling can be configured at any number of distances 30 . For example, common spacing for rules 142 include: wide ruled (or legal ruled) as 11/32 inches (8.7 mm), medium ruled (or college ruled) as 9/32 inches (7.1 mm), or narrow ruled as ¼ in (6.35 mm). Any other spacing dimensions 30 are also possible. Also, the distance 10 from an edge of the paper 140 and margin line 143 can be any number of widths, including a common 1¼ in (31.75 mm). The main writing area (e.g., outside the margin or between dual margins), can have a distance 20 , which can include any number of widths, including standard widths (e.g., letter, legal, A4) less an associated margin or pair of margins.
FIG. 3 shows another exemplary embodiment of the present invention, similar to FIG. 1 , with right end 126 being used to peal top strip 124 from the stack of stickers. Each strip 124 can include two ends 126 without adhesive or only one end 126 (not shown) without adhesive. Preferably, a central area 128 of each strip 124 includes an adhesive layer. The bottom most strip 124 of the stack can be adhered to the marginal area 114 , while each other strip 124 is releasably adhered to the back of the previous strip 124 to form the stack. Each strip can also include a tab area 130 , which may be part of the end 126 . Tab area 130 can be configured to accept indicia (e.g., by a common ink pen or common pencil). This can allow a user to affix a strip off the edge of the paper (e.g., as illustrated), to provide an external tab or flag marker. Additionally or alternatively, strips can still be affixed fully within the edges of the paper, and tab area 130 can act as a customizable area on highlight strip 124 . FIG. 3 illustrates exemplary stickers 124 without a flag portion 137 , and about the same width or slightly smaller than the illustrated papers.
The exemplary highlight strips, e.g., 124 or 125 , can be configured in a number of lengths and heights. For example, highlighter strips can be at least three times longer than they are high. They may have a height proportional to a standard line spacing (e.g., 120%, 110%, 100%, or 90% of 11/32 inch line spacing, or of ¼ inch line spacing). Highlighter strips can have a length proportional to page width dimensions. For example, standard letter sized pages can be about 8.5 inches by 11 inches, with a first margin line at about 1.25 inches from the left edge, and with an optional second margin line at about 1.25 inches from the right edge, e.g., 144 . The highlighter strip 124 can then be proportioned with respect to one of these values, e.g., a full page width of about 8.5 inches, a width outside the margin of about 7.25 inches, or a width outside two margins of about 6 inches. Highlighter strips 124 and/or 125 can be longer than a page width, e.g., the central portion 128 can be about 8.5 inches or central portion 128 and a tab 126 can be about 8.5 inches, while another tab 126 can extend beyond the 8.5 inch page width. Highlighter strips 124 can also be some fractional portion of these values, e.g., 120%, 110%, 100%, or 90% of 8.5 inches, or of 6 inches, etc.
FIG. 4 illustrates another exemplary embodiment, in which base portion 110 includes a flexible flap 150 extending from the bottom end (opposite the binding 118 ) of the base portion 110 . Flap 150 can extend as a continuation of the end of the base portion 110 , e.g., from the end of marginal area 114 , or at a hinge 153 , such as a living hinge. Flap 150 can alternatively extend from a lateral side of the base 110 , and in a certain embodiment from the binding 118 side, and will preferably be connected to a side without the binding member 118 , and more preferably to the side opposite binding member 118 (e.g., the bottom side, as illustrated).
The supply stack of highlighter strips 125 , 137 can then be included on the marginal area 114 and covered by the flap 150 when folded over the stack of sheets 120 . In an alternative embodiment, the stickers 125 can be positioned on the inner side 151 of the flap 150 , such as in an embodiment that does not include a marginal area of the base portion. This flap 150 can be used to hold the bottom of papers 120 (e.g., as illustrated in FIG. 4 ), and/or can be used as a bookmark or divider of two sections of papers 120 (e.g., as shown in FIG. 6 , partitioning paper group 158 and group 156 ). This flap can be configured as a markable surface (e.g., dry erase, cardboard, paper, etc.), and/or a durable surface (e.g., plastic, metal, etc.). Hinge 153 can be removable so that flap 150 can be detached, either permanently, temporarily, or interchangeably. This flap 150 can be transparent or translucent, and in at least one embodiment can be used without the stickers 125 .
FIG. 7 illustrates another exemplary embodiment, including an exemplary stack of highlighter strips 725 . These strips can also include a central portion 728 with adhesive included, an end portion 726 without adhesive included, and an optional second end portion 727 , with or without adhesive included. Highlighter stack 725 can be a stand alone set of highlighter strips, can be included on a base layer (e.g., a release coated substrate) (not shown), within a dispensing container (not shown), or as a refill set of highlighter strips, configured to be affixed to other exemplary embodiments. One or both sides can be free of adhesive. The adhesive-free ends 726 , 727 can be stacked in an alternative position so that when the top strip is lifted, the strips are lifted in a zigzag patterns, which can be useful when used with a container to draw up the next strip with the top one is removed.
FIG. 8 illustrates another exemplary embodiment, including a dispensing roll 860 of a plurality of highlighter strips 825 , e.g., within a dispenser 865 . The roll 860 can include a backing/release carrier tape 880 on which the strips 825 are carried. The tape 880 can have perforations in the backing layer between strips for removing individual strips 828 , 826 . Another detachment arrangement can include a tearable tape 880 to be torn by hand (e.g., a paper based backing with a release coating or layer for example).
In another exemplary embodiment, the roll 860 may rotate about an axis 867 , and each strip 825 can be connected to the next strip, such that pulling on strip 825 can bring the next strip part of the way out of the dispenser 825 . Each strip 825 can be affixed within the roll 860 to include at least some part of central portion 828 over (e.g., affixed to) the next strip's end portion 826 (e.g., a portion without adhesive), which can facilitate a first strip 828 at least partially removing a next strip from roll 860 . The user can then manually separate the first strip from the remaining strips. The roll 860 can be configured to dispense the strips in one long connected string of affixed strips, or can be configured to automatically pull one strip off at a time.
The exemplary roll of strips 860 illustrated in FIG. 8 can be provided as a stand alone entity tape, or can be provided in conjunction with other entities, such as was described in previous embodiments. For example, dispensing entity 870 can be included on the back of notepad base portion 110 or on flap 150 ,
FIG. 9 illustrates another exemplary embodiment where base portion 910 includes a cover of a binder (e.g., a three ring binder). Highlighter strip stack 925 can be included on base portion 910 at any number of locations, e.g., spots 980 - 985 , or any other suitable location. These locations can also include a dispenser roll 870 , or any other configuration of a plurality of highlighter strips. Dashed line 911 illustrates the possible profile of included sheets of paper, making each of spots 980 - 984 a marginal area. While a marginal area may be a preferable location for strips 925 , the highlighter strips can be located anywhere else on the binder, including on the outside cover area.
FIG. 10 illustrates an exemplary embodiment of a single highlighter strip, including grabbing end 126 , optional second end 127 , and a central portion 128 (which can extend to include end 127 in embodiments with only one end 126 ) with a removable adhesive. The strip 128 and removable adhesive can be configured such that indicia 132 is legible beneath strip 124 . The adhesive can cause a temporary, releasable, or permanent bond with various substrates. Initially, the adhesive can form a temporary or releasable bond with at least a first release layer (e.g., the back of another highlighter strip), and subsequently can form a temporary or permanent bond with a substrate (e.g., paper with indicia thereon). Preferably, the bond will remain releasable, allowing highlighter strips to be used, re-used, removed, or otherwise moved to different locations within a substrate or multiple substrates. Other implementations can allow for strips to form a permanent bond once applied to a second substrate (e.g., for applications where a user wants to ensure highlighting is not altered or undone).
All of the references specifically identified in the detailed description section of the present application are expressly incorporated herein in their entirety by reference thereto. The term “about,” as used herein, should generally be understood to refer to both the corresponding number and a range of numbers. Moreover, all numerical ranges herein should be understood to include each whole integer within the range. Moreover, various adhesives and/or bonds are described as temporary and/or permanent. These can relate to a general relative strength between the two, whether the bond would cause structural damage if removed, whether the adhesive can be reused after a previous use, or any number of other relative strength distinctions between permanent, semi-permanent, temporary, and/or removable. In the case of paper envelopes, a permanent adhesion would typically remove a layer of paper along with the strip as it is pulled off. References to more permanent adhesion indicates a noticeably stronger adhesion that a temporary adhesion. Also, exemplary envelopes can be of any size, shape, and/or material, including standards sizes configured to receive one or more standard sized papers, e.g., letter, legal, A4, etc.
In exemplary embodiments described herein, indicia may be used to describe any number of markings, pre-printed text, hand-written text, graphics, images, symbols, or similar. Further, when legibility is discussed, legible can refer to being technically legible (e.g., able to be read), equally legible, and/or highly legible (e.g., near-equal, equal, or even of greater readability). Moreover, certain exemplary highlighter strips can be described as being configured to be placed over indicia while the indicia remains legible, which can include all suitable configurations of the highlighter strips, even if specialized configurations of the indicia would render that indicia illegible. For example, a highlighter strip of a certain color (e.g., yellow) can be configured to be placed over indicia while the indicia remains legible, if certain indicia-characteristics allow it to be legible (e.g., black colored indicia), even if certain other specific indicia-characteristics do not allow it to be legible (e.g., indicia of the exact or near same yellow color).
While illustrative embodiments of the invention are disclosed herein, it will be appreciated that numerous modifications and other embodiments may be devised by those skilled in the art. For example, the features for the various embodiments can be used in other embodiments. Therefore, it will be understood that the appended claims are intended to cover all such modifications and embodiments that come within the spirit and scope of the present invention.
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A highlighter strip including adhesive to form a removable bond with a substrate, constructed from a translucent and colored material. The highlighter strip can be affixed over writing or other markings, which highlights the indicia that remains legible. One or both ends of the strip can omit the adhesive, thereby providing a grabbing portion to facilitate removal from an initial position and optionally subsequent positions. The strip can be included in a set of strips affixed to each other and optionally affixed to another base; such as a notebook, binder, or other entity where one would expect writing, text, or other indicia requiring highlighting.
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TECHNICAL FIELD
The present invention relates to a wavelength selective heat radiation material which selectively radiates heat radiation light corresponding to an infrared ray transmission wavelength region of a resin member and to a method for manufacturing the wavelength selective heat radiation material, and in particular, the present invention relates to a method for manufacturing a wavelength selective heat radiation material which selectively radiates, at a high emissivity, heat radiation light corresponding to an infrared ray transmission wavelength region of a resin member from a heat radiation surface of the wavelength selective heat radiation material toward the resin member, by placing the wavelength selective heat radiation material between a heat generation source and the resin member in an electronic device in which the heat generation source is covered with the resin member having the infrared ray transmission wavelength region.
BACKGROUND ART
In recent years, in association with miniaturization and weight reduction, speeding-up, and multi-functionality of an electronic device, speeding-up and high integration of a semiconductor component have been promoted, and thus, a heat generation density of each element has increased and the local concentration of heat generation has been resulting. In addition, since a variety of resin materials are used in an electronic device-related component, due to the characteristic of the resin material that is the inferiority in heat conductivity, heat generated by the electronic device is caught by a cover or the like made of the resin and is accumulated, thereby leading to the problem in that the temperature increase causes a failure rate of the electronic device to be increased and the life of each component to be shortened.
Therefore, in order to solve the above-mentioned problem, as disclosed in Japanese Patent Application Laid-Open Publication No. 2010-27831 (Patent Literature 1) and Japanese Patent Application Laid-Open Publication No. 2014-33062 (Patent Literature 2), the present inventors et al. developed a method in which in an electronic device in which a heat generation source is covered with a resin member having an infrared ray transmission wavelength region, a wavelength selective heat radiation material in which a multitude of microcavities forming a periodic surface fine uneven pattern are two-dimensionally arrayed is placed between the heat generation source and the resin member, thereby enhancing an infrared ray transmitting property of the resin member with which the heat generation source is covered (providing the resin member with transparency) and improving a heat radiation efficiency of the electronic device; and a wavelength selective heat radiation material used to selectively radiating heat radiation light corresponding to the infrared ray transmission wavelength region of the resin member and a method for manufacturing the same.
In the wavelength selective heat radiation material disclosed in each of Patent Literature 1 and Patent Literature 2, an opening size of each of the microcavities is approximately several μm, and the microcavities are extremely fine depressions. Therefore, in Patent Literature 1, by combining semiconductor photolithography technology and an electrolytic etching method, the microcavities are formed in the wavelength selective heat radiation material, and in Patent Literature 2, by employing nanoimprint technology, a surface fine uneven pattern, periodically repeated in a plane formed on a die, is transcribed and molded to a metal material, thereby forming the microcavities in the wavelength selective heat radiation material.
However, in the conventional technology in which the semiconductor photolithography technology and the electrolytic etching method are combined, an upper portion of a cavity wall of each of the obtained microcavities is chipped or thin-walled, thereby leading to a problem in that it is impossible to selectively radiate the heat radiation light corresponding to the infrared ray transmission wavelength region of the resin member at the emissivity as originally designed. In addition, with respect to the chipping or thin-walling of the upper portion of the cavity wall, there also is a problem in that any finding on what influence to be exerted on the radiation characteristic of the heat radiation light corresponding to the infrared ray transmission wavelength region of the resin member has not been obtained.
In the wavelength selective heat radiation material disclosed in each of Patent Literature 1 and Patent Literature 2, it is preferable that an aspect ratio of each of the microcavities is in a range of 0.8 to 3.0. This is because if the aspect ratio of each of the microcavities is below 0.8, a disadvantage in that a selective radiant intensity is reduced is caused, and on the other hand, if the aspect ratio is above 3.0, a disadvantage in that the formation of the microcavities is extremely difficult is caused.
However, in the conventional technology in which the semiconductor photolithography technology and the electrolytic etching method are combined or the nanoimprint lithography, there is a problem in that it is difficult to form microcavities each having an aspect ratio larger than 3.0 without roughening the upper portion of the cavity wall. Therefore, as the wavelength selective heat radiation material which selectively radiates the heat radiation light corresponding to the infrared ray transmission wavelength region of the resin member, a wavelength selective heat radiation material in which the microcavities each having the aspect ratio larger than 3.0 has not been known. In addition, there also is a problem in that any finding on what emissivity at which the wavelength selective heat radiation material, if the aspect ratio of each of the microcavities is larger than 3.0, is capable of selectively radiating the heat radiation light corresponding to the infrared ray transmission wavelength region of the resin member has not been obtained.
CITATION LIST
Patent Literature
[Patent Literature 1] Japanese Patent Application Laid-Open Publication No. 2010-27831
[Patent Literature 2] Japanese Patent Application Laid-Open Publication No. 2014-33062
[Patent Literature 3] Japanese Patent Application Laid-Open Publication No. 11-74162
[Patent Literature 4] Japanese Patent Application Laid-Open Publication No. 2013-57101
SUMMARY OF THE INVENTION
Technical Problem
Therefore, objects of the present invention are to provide a method for manufacturing, as a wavelength selective heat radiation material which selectively radiates heat radiation light corresponding to an infrared ray transmission wavelength region of a resin member, a wavelength selective heat radiation material in which a surface roughness of an upper portion of a cavity wall defining each microcavity (a size of a chipped portion or a thin-walled portion of the upper portion of the cavity wall) is suppressed or a wavelength selective heat radiation material in which microcavities each having an aspect ratio larger than 3.0 are formed; and a wavelength selective heat radiation material having a form of each of the microcavities, which are effective for selectively radiating the heat radiation light corresponding to the infrared ray transmission wavelength region of the resin member, by investigating heat radiation characteristics of the obtained wavelength selective heat radiation material.
Solution to Problem
The present inventors et al. have made intensive studies on a method for manufacturing a wavelength selective heat radiation material which selectively radiates heat radiation light corresponding to an infrared ray transmission wavelength region of a resin member. As a result, the present inventors et al. have found that a base material to whose one surface a mask having predetermined openings is previously caused to tightly adhere or a base material in which depressions are previously formed on the one surface thereof by pressing a die having projections arrayed so as to correspond to positions of microcavities thereagainst is subjected to anisotropic etching, thereby allowing a wavelength selective heat radiation material in which a surface roughness of an upper portion of a cavity wall defining each of the microcavities is suppressed or a wavelength selective heat radiation material having an aspect ratio of each of the microcavities larger than 3.0 to be obtained.
In addition, by investigating characteristics of the obtained wavelength selective heat radiation material, the present inventors et al. have found the form of each of the microcavities which are effective for selectively radiating the heat radiation light corresponding to the infrared ray transmission wavelength region of the resin member (an opening ratio, an aspect ratio, and a surface roughness of an upper portion of a cavity wall), thereby reaching the completion of the present invention.
Specifically, according to the present invention, by employing a first method for manufacturing a wavelength selective heat radiation material, the method including the steps of: (a) placing a mask having predetermined openings on one surface of a base material and causing the mask to tightly adhere to the one surface; (b) etching the base material at the openings of the mask and forming microcavities in the base material; and (c) exfoliating the mask from the base material, provided is a wavelength selective heat radiation material for selectively radiating heat radiation light corresponding to an infrared ray transmission wavelength region of a resin member, the wavelength selective heat radiation material having a heat radiation surface, the heat radiation surface having a multitude of microcavities formed therein, the microcavities having rectangular openings being periodically repeated and being two-dimensionally arrayed in a grating-like manner, and the microcavities each having an opening ratio a/Λ (a: opening size, Λ: opening period) in a range of 0.5 to 0.9 and each having 1 μm or less of a surface roughness Rz (a size of a chipped portion or a thin-walled portion of an upper portion of a cavity wall) of the upper portion of the cavity wall each defining the microcavities.
In addition, according to the present invention, also by employing a second method for manufacturing a wavelength selective heat radiation material, the method including the steps of: (a) forming depressions in one surface of a base material by pressing a die having projections against the one surface, the projections being arrayed so as to correspond to positions of microcavities; and (b) forming the microcavities in the base material by etching the base material, provided is a wavelength selective heat radiation material for selectively radiating heat radiation light corresponding to an infrared ray transmission wavelength region of a resin member, the wavelength selective heat radiation material having a heat radiation surface, the heat radiation surface having a multitude of microcavities formed therein, the microcavities having rectangular openings being periodically repeated and being two-dimensionally arrayed in a grating-like manner, and the microcavities each having an opening ratio a/Λ (a: opening size, Λ: opening period) in a range of 0.5 to 0.9 and each having 1 μm or less of a surface roughness Rz (a size of a chipped portion or a thin-walled portion of an upper portion of a cavity wall) of the upper portion of the cavity wall each defining the microcavities.
It is to be noted that as shown in FIG. 11 and FIG. 13 , the surface roughness Rz of the upper portion of the cavity wall denotes a depth of a chipped portion of the cavity wall from an upper surface of each of the microcavities in the upper portion of the cavity wall each defining the microcavities or a length of a portion, which is thinner than an originally planned thickness of the cavity wall, from the upper surface of each of the microcavities.
The wavelength selective heat radiation material according to the present invention is applicable to a wavelength selective heat radiation material which in an electronic device or the like whose heat generation source is covered with a resin member having an infrared ray transmission wavelength region, is placed between the heat generation source and the resin member so as to cover said heat generation source; to which heat energy from the heat generation source is transferred or inputted by heat radiation; and which selectively radiates heat radiation light included in the infrared ray transmission wavelength region of the resin member from a heat radiation surface of the wavelength selective heat radiation material toward the resin member.
In particular, in a case where the aspect ratio d/a (d: opening depth, a: opening size) of each of the microcavities is 3.3 or more, the wavelength selective heat radiation material according to the present invention exhibits a high emissivity, which is 0.85 or more, with respect to the heat radiation light corresponding to the infrared ray transmission wavelength region of the resin member. Therefore, the wavelength selective heat radiation material according to the present invention is beneficial for enhancing a heat radiation efficiency of the heat generation source covered with the resin member having the infrared ray transmission wavelength region.
In the wavelength selective heat radiation material according to the present invention, as indicated by the simulation test shown in FIG. 12 , when the surface roughness Rz of the upper portion of the cavity wall each defining the microcavities becomes larger than 1 μm, a peak of a spectral emissivity in a wavelength range of 4.75 to 5.75 μm in particular is reduced. In addition, when the surface roughness Rz of the upper portion of the cavity wall becomes larger than 1 μm, regardless of a depth d of an opening of each of the microcavities, a spectral emissivity in a wavelength range of 1 to 10 μm is reduced, and a peak of a spectral emissivity in a wavelength range of 3 to 5.5 μm in particular is reduced. Therefore, it is made difficult to selectively radiate the heat radiation light included in the infrared ray transmission wavelength region of the resin member.
In the present invention, it is preferable that the opening ratio of each of the microcavities formed in the heat radiation surface of the wavelength selective heat radiation material is in a range of 0.5 to 0.9.
This is because when the opening ratio of each of the microcavities is less than 0.5, brought about is a disadvantage in that selectivity for the heat radiation light corresponding to the infrared ray transmission wavelength region of the resin member is reduced; and conversely, when the opening ratio is above 0.9, brought about is a disadvantage in that structure stability of a fine structure is reduced.
In addition, it is preferable that the aspect ratio d/a (d: opening depth, a: opening size) of each of the microcavities formed in the heat radiation surface of the wavelength selective heat radiation material is 3.3 or more.
This is because in a region in which the aspect ratio d/a of each of the microcavities is less than 3.3, in accordance with an increase in the aspect ratio d/a, an emissivity of the heat radiation light corresponding to the infrared ray transmission wavelength region of the resin member is sharply increased up to approximately 0.85, whereas in a region in which the aspect ratio d/a is 3.3 or more, with respect to a rate of an increase in the aspect ratio d/a, a rate of an increase in the emissivity of heat radiation light corresponding to the infrared ray transmission wavelength region of the resin member is sharply decreased and nearly levels off in a range of 0.85 to 1.0.
As described above, in order to maximize the heat radiation efficiency of the heat generation source, it is preferable that the wavelength selective heat radiation material according to the present invention is placed between the heat generation source and the resin member so as to cover said heat generation source. Furthermore, it is preferable that as the heat radiation light included in the infrared ray transmission wavelength region of the resin member, infrared light which exerts great influence on heat transfer is targeted.
In the heat radiation surface of the wavelength selective heat radiation material according to the present invention, the multitude of microcavities whose surface have been textured (surface texturing) are present. It is preferable that each of these microcavities is opened in a rectangular shape or a circular shape so as to have a predetermined opening ratio and a predetermined aspect ratio; and each of the microcavities is formed at the substantially same period as a period of a wavelength in the infrared ray transmission wavelength region of the resin member covering the heat generation source or at a period being shorter by 1 μm than the period of the wavelength in the infrared ray transmission wavelength region of the resin member covering the heat generation source.
The reason is that when the period at which each of the microcavities is formed is made the substantially same period of the wavelength of the infrared ray transmission wavelength region of the resin member covering the heat generation source, surface plasmon resonance occurs in the periodic structure and an electromagnetic field of the heat radiation light, and therefore, the emissivity in the infrared ray transmission wavelength region of the resin member is increased (resonance effect).
In addition, the reason is that when the period at which each of the microcavities is formed is made the period being shorter by 1 μm than the period of the wavelength in the infrared ray transmission wavelength region of the resin member covering the heat generation source, a wavelength of a mode having the strongest intensity among the electromagnetic waves confined within the microcavities and the wavelength of the infrared ray transmission wavelength region of the resin member can coincide with each other, and as a result, an emissivity in the infrared ray transmission wavelength region of the resin member is increased (cavity effect).
It is preferable that the microcavities are arrayed in a grating-like manner in a radiation surface in a plane view. This is because the grating-like array efficiently increases an emissivity of heat energy rays. It is to be noted that the present invention is not limited to the grating-like array only, but other array such as an array having a honeycomb structure may be adopted.
In addition, it is preferable that the wavelength selective heat radiation material in which the microcavities are formed is formed of a metal material whose emissivity in an infrared region of a wavelength of 1 to 10 μm is 0.4 or less. This is because when the emissivity in the infrared region exceeds 0.4, a disadvantage in that selective radiation characteristics are reduced is brought about.
In addition, it is preferable that a period at which each of the microcavities is arrayed is 4 to 7 μm and only the infrared light in the infrared ray transmission wavelength region of the resin member covering the heat generation source can be selectively radiated. This is because although an absorption wavelength region and a transmission wavelength region of the infrared light are slightly different from each other, depending on a kind of resin, it is often the case that most of the resin materials currently used as a material for an electronic device indicate the above-mentioned wavelength region.
Therefore, it is preferable that the wavelength selective heat radiation material according to the present invention is placed between the heat generation source and the resin member covering said heat generation source.
As described above, the base material to whose one surface the mask having the predetermined openings is previously caused to tightly adhere or the base material in which the depressions are previously formed on the one surface thereof by pressing the die having the projections arrayed so as to correspond to the positions of microcavities thereagainst is subjected to the anisotropic etching, thereby allowing the wavelength selective heat radiation material according to the present invention to be manufactured.
In the manufacturing of the wavelength selective heat radiation material according to the present invention, when the anisotropic etching process is conducted by employing an electrochemical etching method or a chemical etching method, the etching is started preferentially from the openings of the mask or the depressions, thereby allowing the formation of etching pits, whose etching starting positions are controlled at a high precision, to be realized. As a result, the wavelength selective heat radiation material in which the high precision microcavities whose surface roughness Rz of the upper portion of the cavity wall defining each of the microcavities is suppressed to be 1 μm or less or the microcavities each having an aspect ratio larger than 3.0 whose surface expansion efficiency is high are formed can be easily obtained.
In addition, in the above-mentioned anisotropic etching process, it is preferable that the base material used for manufacturing the wavelength selective heat radiation material is constituted of a metal foil of aluminum or an aluminum alloy whose area occupancy ratio of a (100) crystal plane is 93% or more. In order to obtain a large (100) crystal plane, it is advantageous to use a metal foil constituted of aluminum or an aluminum alloy which has been subjected to an annealing process.
When the metal foil whose (100) crystal plane is oriented preferentially with respect to a surface and which is constituted of the aluminum or the aluminum alloy whose area occupancy ratio is 93% or more is used, the microcavities oriented perpendicularly to the heat radiation surface can be easily obtained.
In the above-mentioned anisotropic etching process, in the case where the mask having the predetermined openings is previously caused to tightly adhere to the one surface of the base material, it is preferable that said mask is constituted of a flexible polymer. Having the flexibility facilitates the adhesion and exfoliation operations for the mask, thereby facilitating the manufacturing of a desired wavelength selective heat radiation material.
In the case where the mask is constituted of the polymer, although a material of the mask is not particularly limited, a polycarbonate, polypropylene, polyethersulfone, polyamide, cellulose acetate, triacetylcellulose, polytetrafluoroethylene, an epoxy-based polymer, or the like may be used.
In addition, it is preferable that the mask is caused to tightly adhere to the metal foil by exerting a load thereon from the surface. In consideration of adhesiveness of the mask and the prevention of damage to the base material, it is preferable that the load exerted on the mask is in a range of 10 4 to 10 6 Pa.
By exerting the load on the mask, the mask is caused to tightly adhere to the metal foil surface, thereby allowing a desired tight adhesion state to be more accurately obtained. By causing the mask to accurately adhere tightly to the foil surface, an unnecessary etching liquid or the like comes not to enter between the mask surface and the foil surface, thereby allowing desired etching to be more precisely and accurately conducted through the openings of the mask.
More specifically, by using a stamp having a semi-cylindrical-shaped pressing surface and performing pressing and swinging, the mask can be transcribed. In addition, it is preferable that the pressing surface of the semi-cylindrical-shaped stamp has a curvature of 0.01 to 0.2.
The pressing surface of the stamp has the semi-cylindrical-shaped curvature, and thus, it can be prevented that entering of air between the metal foil in which the microcavities are formed and the mask or between the metal foil and the stamp upon the transcription of the mask hinders the transcription of the pattern. In addition, when the pressing surface of the stamp has the semi-cylindrical-shaped curvature, the load exerted on the mask can also be reduced.
Furthermore, in the anisotropic etching process, in the case where the mask having the predetermined openings is previously caused to tightly adhere to the one surface of the base material, it is preferable that prior to the etching, a thin film of copper having a thickness of 5 to 20 nm is formed on an upper surface of the mask by evaporation or sputtering, since the formation of uniform microcavities is promoted.
In the above-mentioned anisotropic etching process, it is preferable that the metal foil is subjected to a chemical polishing process or an electrolytic polishing process, prior to causing the mask having the predetermined openings to tightly adhere to the one surface of the metal foil in the case where the mask having the predetermined openings is previously caused to tightly adhere to the one surface of the metal foil or prior to forming the depressions in the one surface of the metal foil in the case where by pressing the die having the projections arrayed so as to correspond to the positions of microcavities thereagainst, the depressions are previously formed on the one surface of the metal foil.
On the surface of the metal foil constituted of the aluminum or the aluminum alloy, in the manufacturing processes including the annealing process, an ununiform oxide film layer, dirt, flaws, and the like are present. Therefore, by removing these through the polishing process, the oxide film layer or the like formed on the surface of the metal foil is uniformized and homogenized. As a result of this, selectivity with respect to the starting of the etching from the depressions is enhanced, thereby making it possible to realize enhancement in a precision at which a starting point of the etching is controlled.
In addition, in a case where the polishing process is the electrolytic polishing process, by using, for example, a mixed solution of perchloric acid and ethanol, the electrolytic polishing can be conducted.
The anisotropic etching process used for forming the microcavities can be conducted by employing either of the electrochemical etching method or the chemical etching method. However, in particular, the electrolytic etching allows the microcavities to be formed at an excellent precision without using complex equipment. Therefore, the electrolytic etching is suitable for manufacturing the wavelength selective heat radiation material according to the present invention. The electrolytic etching can be conducted, for example, by using a 5M to 7M hydrochloric acid aqueous solution and at a temperature of 25° C. to 45° C. or more.
In addition, in the electrolytic etching process, in the case where the mask having the predetermined openings is previously caused to tightly adhere to the one surface of the metal foil, it is preferable that a small amount of a surfactant, any of alcohols, or the like, as a component which allows wettability of the mask to be improved, is added to an electrolysis liquid, in order to allow the electrolysis liquid in the electrolytic etching to quickly infiltrate into fine pores of the mask and of a support or the like of the mask, which is placed continuously with the mask.
When the electrolysis liquid to which the small amount of the surfactant, any of alcohols, or the like is added is used, since the metal foil is electrolytically etched through the openings of the mask, the metal foil in which the microcavities are formed at an excellent precision can be manufactured.
As specific conditions under which the electrolytic etching is conducted, it is preferable that an electrolytic bath whose bath composition is a 5M to 7M hydrochloric acid aqueous solution and whose bath temperature is 25° C. to 45° C. is used; a current density upon starting electrolysis is 1500 mA/cm 2 ; and after decreasing the current density at a current density decrease rate of 150 mA/cm 2 /s up to 200 mA/cm 2 , the current density of 200 mA/cm 2 is retained for 5 to 40 seconds, and it is more preferable that the bath temperature in the electrolytic etching is 30° C. to 40° C. and a retention time at the current density of 200 mA/cm 2 is 5 to 15 seconds.
According to the present invention, the base material to whose one surface the mask having the predetermined openings is previously caused to tightly adhere or the base material in which the depressions are previously formed on the one surface thereof by pressing the die having the projections arrayed so as to correspond to the positions of microcavities thereagainst is subjected to the anisotropic etching. Thus, it is made possible to obtain the wavelength selective heat radiation material whose surface roughness (the size of the chipped portion or the thin-walled portion of the upper portion of the cavity wall) of the upper portion of the cavity wall defining each of the microcavities is suppressed and whose aspect ratio of each of the microcavities is larger than 3.0.
In addition, according to the present invention, the method for manufacturing the wavelength selective heat radiation material, which includes the step of previously transcribing the mask on the one surface of the base material by using the stamp having the semi-cylindrical-shaped pressing surface, can be provided. Thus, it can be prevented that upon the transcribing for the mask, entering of air between the metal foil and the mask hinders the transcription of the pattern. In addition, since adhesiveness of the mask is enhanced, the unnecessary etching liquid or the like is prevented from entering between the surface of the mask and the surface of the metal foil, thereby allowing the desired etching to be more precisely and accurately conducted through the openings of the mask.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram illustrating microcavities formed in a wavelength selective heat radiation material according to the present invention.
FIG. 2 shows electron microscope photographs of the wavelength selective heat radiation material obtained by changing a bath temperature of an electrolytic bath in a method according to the present invention for manufacturing the wavelength selective heat radiation material.
FIG. 3 is a characteristic curve graph showing a relationship between a wavelength and a spectral emissivity of the wavelength selective heat radiation material obtained by changing the bath temperature of the electrolytic bath in the method according to the present invention for manufacturing the wavelength selective heat radiation material.
FIG. 4 shows electron microscope photographs of a wavelength selective heat radiation material obtained by changing an electrolysis time in the method according to the present invention for manufacturing the wavelength selective heat radiation material.
FIG. 5 is a characteristic curve graph showing a relationship between a wavelength and a spectral emissivity of the wavelength selective heat radiation material obtained by changing the electrolysis time in the method according to the present invention for manufacturing the wavelength selective heat radiation material.
FIG. 6 shows electron microscope photographs of a wavelength selective heat radiation material obtained under optimal electrolysis conditions in the method according to the present invention for manufacturing the wavelength selective heat radiation material.
FIG. 7 is a characteristic curve graph showing a relationship between a wavelength and a spectral emissivity of the wavelength selective heat radiation material obtained under the optimal conditions in the method according to the present invention for manufacturing the wavelength selective heat radiation material.
FIG. 8 is a schematic diagram illustrating an outline of a stamp used in the transcription of a mask.
FIG. 9 are characteristic curve graphs, each showing a relationship between a wavelength and a spectral emissivity of a wavelength selective heat radiation material, in cases where depths of each microcavity are different from one another.
FIG. 10 is a characteristic curve graph showing a relationship between a wavelength and a spectral emissivity, in a case where opening sizes of each microcavity are different from one another.
FIG. 11 are schematic diagrams each illustrating a wavelength selective heat radiation material, in a case where a surface roughness Rz of an upper portion of a cavity wall is changed.
FIG. 12 is a characteristic curve graph showing a relationship between a wavelength and a spectral emissivity of a wavelength selective heat radiation material, obtained by conducting a numerical analysis with respect to an analytical model, in case where the surface roughness Rz of the upper portion of the cavity wall is changed.
FIG. 13 are schematic diagrams each illustrating a wavelength selective heat radiation material, in a case where a depth of each microcavity having a surface roughness Rz of an upper portion of a cavity wall, which is 2 μm, is changed.
FIG. 14 is a characteristic curve graph showing a relationship between a wavelength and a spectral emissivity of a wavelength selective heat radiation material, obtained by conducting a numerical analysis with respect to the analytical model, in case where the depth of each microcavity having the surface roughness Rz of the upper portion of the cavity wall, which is 2 μm, is changed.
FIG. 15 is a schematic diagram illustrating a wavelength selective heat radiation material in a case where the depth of each microcavity is changed.
FIG. 16 is a characteristic curve graph showing a relationship between a wavelength and a spectral emissivity of a wavelength selective heat radiation material, obtained conducting a numerical analysis with respect to the analytical model, in a case where the depth of each microcavity is changed.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinafter, with reference to Examples and Comparative Examples, a preferred embodiment of the present invention will be described. It is to be noted that the present invention is not limited to Examples described below and a variety of modifications within the scope not departing from the technical ideas of the present invention are possible.
Example 1
An aluminum foil whose area occupancy ratio of a (100) crystal plane of a surface was 93% or more was used, said aluminum foil was subjected to electrolytic polishing by using a perchloric acid/ethanol bath, and thereafter, a neoprene thin film layer having a structure in which fine pores each having a size of 2 μm were regularly arrayed at intervals of 5 μm was caused to tightly adhere to the surface thereof for formation. Copper was attached to said aluminum foil by conducting a sputtering process; thereafter, by using an electrolytic bath having a bath temperature of 25° C. and containing a 7M hydrochloric acid aqueous solution, electrolytic etching to the resultant was conducted under the conditions that a current density upon starting electrolysis was 1500 mA/cm 2 and after decreasing the current density at a current density decrease rate of 150 mA/cm 2 /s up to 200 mA/cm 2 , the current density of 200 mA/cm 2 was retained for 15 seconds. Thereafter, the resultant was immersed in a 1 wt % aqueous solution of a sodium hydroxide; ultrasonic cleaning was conducted for 1 minute and 30 seconds; and the neoprene thin film layer was thereby removed, thereby obtaining a wavelength selective heat radiation material in which microcavities each having a length a of one side of 3 μm and an opening ratio a/Λ (a: opening size, Λ: opening period) of 0.6 were formed. An electron microscope photograph of a heat radiation surface of the obtained wavelength selective heat radiation material is shown in FIG. 2A .
Example 2
Under the same conditions as in Example 1, except that the bath temperature of the electrolytic bath was 30° C., electrolytic etching was conducted, thereby obtaining a wavelength selective heat radiation material in which microcavities each having a length a of one side of 3 μm and an opening ratio a/Λ (a: opening size, Λ: opening period) of 0.6 were formed.
Example 3
Under the same conditions as in Example 1, except that the bath temperature of the electrolytic bath was 35° C., electrolytic etching was conducted, thereby obtaining a wavelength selective heat radiation material in which microcavities each having a length a of one side of 3 μm and an opening ratio a/Λ (a: opening size, Λ: opening period) of 0.6 were formed.
Example 4
Under the same conditions as in Example 1, except that the bath temperature of the electrolytic bath was 40° C., electrolytic etching was conducted, thereby obtaining a wavelength selective heat radiation material in which microcavities each having a length a of one side of 3 μm and an opening ratio a/Λ (a: opening size, Λ: opening period) of 0.6 were formed. An electron microscope photograph of a heat radiation surface of the obtained wavelength selective heat radiation material is shown in FIG. 2B .
Example 5
Under the same conditions as in Example 1, except that the bath temperature of the electrolytic bath was 45° C., electrolytic etching was conducted, thereby obtaining a wavelength selective heat radiation material in which microcavities each having a length a of one side of 3 μm and an opening ratio a/Λ (a: opening size, Λ: opening period) of 0.6 were formed.
Example 6
Under the same conditions as in Example 1, except that the bath temperature of the electrolytic bath was 50° C., electrolytic etching was conducted, thereby obtaining a wavelength selective heat radiation material in which microcavities each having a length a of one side of 3 μm and an opening ratio a/Λ (a: opening size, Λ: opening period) of 0.6 were formed. An electron microscope photograph of a heat radiation surface of the obtained wavelength selective heat radiation material is shown in FIG. 2C .
A relationship between a wavelength and a spectral emissivity of each of the wavelength selective heat radiation materials in Example 1 to Example 6, obtained by conducting the measurements using a Fourier transform infrared spectrophotometer (FT/IR-4100, manufactured by JASCO) and a regular reflection unit (RF-81S, manufactured by JASCO), is shown in FIG. 3 . The measurements were conducted under the conditions that a detector was TGS, a resolution was 4 cm −1 , a number of times of integration was 32, and a measurement band was 550 cm −1 to 7800 cm −1 .
It was found out from FIG. 3 that in the method for manufacturing the wavelength selective heat radiation material according to the present invention, when preferably, the bath temperature of the electrolytic bath was in a range of 25° C. to 45° C. and more preferably, was in a range of 30° C. to 40° C., the wavelength selective heat radiation material having excellent wavelength selectivity in a wavelength range of 7 μm or less was obtained.
Example 7
An aluminum foil whose area occupancy ratio of a (100) crystal plane of a surface was 93% or more was used, said aluminum foil was subjected to electrolytic polishing by using a perchloric acid/ethanol bath, and thereafter, a neoprene thin film layer having a structure in which fine pores each having a size of 2 μm were regularly arrayed at intervals of 5 μm was caused to tightly adhere to the surface thereof for formation. Copper was attached to said aluminum foil by conducting a sputtering process; thereafter, by using an electrolytic bath having a bath temperature of 40° C. and containing a 7M hydrochloric acid aqueous solution, electrolytic etching to the resultant was conducted under the conditions that a current density upon starting electrolysis was 1500 mA/cm 2 and after decreasing the current density at a current density decrease rate of 150 mA/cm 2 /s up to 200 mA/cm 2 , the current density of 200 mA/cm 2 was retained for 5 seconds. Thereafter, the resultant was immersed in a 1 wt % aqueous solution of a sodium hydroxide; ultrasonic cleaning was conducted for 1 minute and 30 seconds; and the neoprene thin film layer was thereby removed, thereby obtaining a wavelength selective heat radiation material in which microcavities each having a length a of one side of 3 μm and an opening ratio a/Λ (a: opening size, Λ: opening period) of 0.6 were formed. An electron microscope photograph of a heat radiation surface of the obtained wavelength selective heat radiation material is shown in FIG. 4A .
Example 8
Under the same conditions as in Example 7, except that the retention time at the current density of 200 mA/cm 2 was 10 seconds, electrolytic etching was conducted, thereby obtaining a wavelength selective heat radiation material in which microcavities each having a length a of one side of 3 μm and an opening ratio a/Λ (a: opening size, Λ: opening period) of 0.6 were formed.
Example 9
Under the same conditions as in Example 7, except that the retention time at the current density of 200 mA/cm 2 was 15 seconds, electrolytic etching was conducted, thereby obtaining a wavelength selective heat radiation material in which microcavities each having a length a of one side of 3 μm and an opening ratio a/Λ (a: opening size, Λ: opening period) of 0.6 were formed. An electron microscope photograph of a heat radiation surface of the obtained wavelength selective heat radiation material is shown in FIG. 4B .
Example 10
Under the same conditions as in Example 7, except that the retention time at the current density of 200 mA/cm 2 was 20 seconds, electrolytic etching was conducted, thereby obtaining a wavelength selective heat radiation material in which microcavities each having a length a of one side of 3 μm and an opening ratio a/Λ (a: opening size, Λ: opening period) of 0.6 were formed.
Example 11
Under the same conditions as in Example 7, except that the retention time at the current density of 200 mA/cm 2 was 30 seconds, electrolytic etching was conducted, thereby obtaining a wavelength selective heat radiation material in which microcavities each having a length a of one side of 3 μm and an opening ratio a/Λ (a: opening size, Λ: opening period) of 0.6 were formed.
Example 12
Under the same conditions as in Example 7, except that the retention time at the current density of 200 mA/cm 2 was 40 seconds, electrolytic etching was conducted, thereby obtaining a wavelength selective heat radiation material in which microcavities each having a length a of one side of 3 μm and an opening ratio a/Λ (a: opening size, Λ: opening period) of 0.6 were formed.
Example 13
Under the same conditions as in Example 7, except that the retention time at the current density of 200 mA/cm 2 was 50 seconds, electrolytic etching was conducted, thereby obtaining a wavelength selective heat radiation material in which microcavities each having a length a of one side of 3 μm and an opening ratio a/Λ (a: opening size, Λ: opening period) of 0.6 were formed. An electron microscope photograph of a heat radiation surface of the obtained wavelength selective heat radiation material is shown in FIG. 4C .
A relationship between a wavelength and a spectral emissivity of each of the wavelength selective heat radiation materials in Example 7 to Example 13, obtained by conducting the measurements using a Fourier transform infrared spectrophotometer (FT/IR-4100, manufactured by JASCO) and a regular reflection unit (RF-81S, manufactured by JASCO), is shown in FIG. 5 . The measurements were conducted under the conditions that a detector was TGS, a resolution was 4 cm −1 , a number of times of integration was 32, and a measurement band was 550 cm −1 to 7800 cm −1 .
It was found out from FIG. 5 that in the method for manufacturing the wavelength selective heat radiation material according to the present invention, when preferably, the retention time at the current density of 200 mA/cm 2 was in a range of 5 to 40 seconds and more preferably, was in a range of 5 to 15 seconds, the wavelength selective heat radiation material having excellent wavelength selectivity in a wavelength range of 7 μm or more was obtained.
In view of the results of Example 1 to 13, under the below-described electrolysis conditions considered to be optimal, a wavelength selective heat radiation material in Example 14 was prepared.
Example 14
An aluminum foil whose area occupancy ratio of a (100) crystal plane of a surface was 93% or more was used, said aluminum foil was subjected to electrolytic polishing by using a perchloric acid/ethanol bath, and thereafter, a neoprene thin film layer having a structure in which fine pores each having a size of 2 μm were regularly arrayed at intervals of 5 μm was caused to tightly adhere to the surface thereof for formation. Copper was attached to said aluminum foil by conducting a sputtering process; thereafter, by using an electrolytic bath having a bath temperature of 40° C. and containing a 7M hydrochloric acid aqueous solution, electrolytic etching to the resultant was conducted under the conditions that a current density upon starting electrolysis was 1500 mA/cm 2 and after decreasing the current density at a current density decrease rate of 150 mA/cm 2 /s up to 200 mA/cm 2 , the current density of 200 mA/cm 2 was retained for 15 seconds. Thereafter, the resultant was immersed in a 1 wt % aqueous solution of a sodium hydroxide; ultrasonic cleaning was conducted for 1 minute and 30 seconds; and the neoprene thin film layer was thereby removed, thereby preparing the wavelength selective heat radiation material in which microcavities each having a length a of one side of 3 μm, an opening ratio a/Λ (a: opening size, Λ: opening period) of 0.6, and an aspect ratio of 16/3 were formed.
Electron microscope photographs of the obtained wavelength selective heat radiation material is shown in FIG. 6 . FIGS. 6A and 6B show the electron microscope photographs of a heat radiation surface of the wavelength selective heat radiation material, whose magnifications are different from each other, and FIG. 6C shows the electron microscope photograph of a replica of the heat radiation surface of the obtained wavelength selective heat radiation material for measuring an opening depth of each of the formed microcavities. In addition, a relationship between a wavelength and a spectral emissivity of the wavelength selective heat radiation material in Example 14, obtained by conducting the measurements at a plurality of times (5 portions) using a Fourier transform infrared spectrophotometer (FT/IR-4100, manufactured by JASCO) and a regular reflection unit (RF-81S, manufactured by JASCO), is shown in FIG. 7 . The measurements were conducted under the conditions that a detector was TGS, a resolution was 4 cm −1 , a number of times of integration was 32, and a measurement band was 550 cm −1 to 7800 cm −1 .
It was found out from FIG. 6 that by previously causing the mask having the predetermined openings to tightly adhere to the one surface and conducting the anisotropic electrolytic etching, it was made possible to form, in a heat radiation surface of the wavelength selective heat radiation material, microcavities each having a length a of one side of 3 μm, a depth d of 16 μm, an opening ratio a/Λ of 0.6, an aspect ratio of 16/3, and a surface roughness Rz of an upper portion of a cavity wall being suppressed to be 1 μm or less. In addition, it was found out from FIG. 7 that the obtained wavelength selective heat radiation material had a small variation in the relationship between the wavelength and the spectral emissivity, exhibited excellent wavelength selectivity in a wavelength range of 7 μm or more, and had a peak of the emissivity around a wavelength of 6 μm.
Next, in order to control the opening depth d of each of the microcavities, experiments relating to the influence exerted on the opening depth d of each of the microcavities by an electrolysis time were conducted.
Examples 15 to 18
An aluminum foil whose area occupancy ratio of a (100) crystal plane of a surface was 93% or more was used, said aluminum foil was subjected to electrolytic polishing by using a perchloric acid/ethanol bath, and thereafter, a neoprene thin film layer having a structure in which fine pores each having a size of 2 μm were regularly arrayed at intervals of 5 μm was caused to tightly adhere to the surface thereof for formation. Copper was attached to said aluminum foil by conducting a sputtering process; thereafter, by using an electrolytic bath having a bath temperature of 40° C. and containing a 7M hydrochloric acid aqueous solution, by using a carbon plate as a counter electrode, by setting a constant current of 1500 mA/cm 2 (constant current density), and by changing the electrolysis time to be 0.5, 3.0, 5.0, and 10 seconds, electrolytic etching was conducted. Thereafter, the resultant was immersed in a 1 wt % aqueous solution of a sodium hydroxide; ultrasonic cleaning was conducted for 1 minute and 30 seconds; and the neoprene thin film layer was thereby removed, thereby forming an orthogonal regular array of microcavities in each of Examples 15 to 18.
The adhesion of the neoprene thin film layer onto the surface of the aluminum foil was conducted by using a semi-cylindrical-shaped stamp 1 having a pressing surface 2 whose curvature was 0.01 to 0.2 as shown in FIG. 8 and pressing the stamp 1 thereagainst with a load of 10 4 to 10 6 Pa while swinging were being conducted. As a result, it was made possible to cause the neoprene thin film layer to accurately and firmly adhere tightly thereto with no air entering between the neoprene thin film layer and the surface of the aluminum foil. The opening depths d of the microcavities in the obtained Examples 15 to 18 are shown in Table 1.
TABLE 1
Example No.
(Electrolysis time)
Example 15
Example 16
Example 17
Example 18
(0.5 second)
(3.0 seconds)
(5.0 seconds)
(10 seconds)
Opening
1.0 μm
2.5 μm
5.4 μm
9.0 μm
depth: d
A relationship between a wavelength and a spectral emissivity of each of the wavelength selective heat radiation materials in Examples 15 to 18, obtained by conducting the measurements using a Fourier transform infrared spectrophotometer (FT/IR-4100, manufactured by JASCO) and a regular reflection unit (RF-81S, manufactured by JASCO), is shown in FIG. 9 . The measurements were conducted under the conditions that a detector was TGS, a resolution was 4 cm −1 , a number of times of integration was 32, and a measurement band was 550 cm −1 to 7800 cm −1 .
It was confirmed from Table 1 that the opening depth d of each of the microcavities was deepened substantially in proportion to the electrolysis time. In addition, it was found out from FIG. 9 that the characteristic of the wavelength selective heat radiation material varied depending on the opening depth d of each of the microcavities and in each of Examples 17 and 18 whose opening depths d were 5.4 μm and 9.0 μm, respectively, each of the wavelength selective heat radiation materials exhibited excellent wavelength selectivity in a wavelength range of 7 μm or more in particular and had a peak of the emissivity around a wavelength of 6 μm.
Next, in order to control the opening size a of each of the microcavities, experiments relating to the influence exerted on the opening size a of each of the microcavities by the bath temperature of the electrolytic bath were conducted.
Examples 19 to 23
An aluminum foil whose area occupancy ratio of a (100) crystal plane of a surface was 93% or more was used, said aluminum foil was subjected to electrolytic polishing by using a perchloric acid/ethanol bath, and thereafter, a neoprene thin film layer having a structure in which fine pores each having a size of 2 μm were regularly arrayed at intervals of 5 μm was caused to tightly adhere to the surface thereof for formation. Copper was attached to said aluminum foil by conducting a sputtering process; thereafter, under the condition that an electrolysis time was 3 seconds, by using an electrolytic bath containing a 7M hydrochloric acid aqueous solution, by using a carbon plate as a counter electrode, by setting a constant current of 1500 mA/cm 2 (constant current density), and by changing the bath temperature to be 30° C. 35° C., 40° C., 45° C. and 50° C., electrolytic etching was conducted. Thereafter, the resultant was immersed in a 1 wt % aqueous solution of a sodium hydroxide; ultrasonic cleaning was conducted for 1 minute and 30 seconds; and the neoprene thin film layer was thereby removed, thereby forming an orthogonal regular array of microcavities in each of Examples 19 to 23.
The adhesion of the neoprene thin film layer onto the surface of the aluminum foil was conducted by using a semi-cylindrical-shaped stamp 1 having a pressing surface 2 whose curvature was 0.01 to 0.2 as shown in FIG. 8 and pressing the stamp 1 thereagainst with a load of 10 4 to 10 6 Pa while swinging were being conducted. As a result, it was made possible to cause the neoprene thin film layer to accurately and firmly adhere tightly thereto with no air entering between the neoprene thin film layer and the surface of the aluminum foil. The opening sizes a of the microcavities in the obtained Examples 19 to 23 are shown in Table 2.
TABLE 2
Example No.
(Bath temperature)
Example 19
Example 20
Example 21
Example 22
Example 23
(30° C.)
(35° C.)
(40° C.)
(45° C.)
(50° C.)
Opening size: a
3.6 μm
3.2 μm
3.0 μm
2.7 μm
2.5 μm
A relationship between a wavelength and a spectral emissivity of each of the wavelength selective heat radiation materials in Examples 19 to 23, obtained by conducting the measurements using a Fourier transform infrared spectrophotometer (FT/IR-4100, manufactured by JASCO) and a regular reflection unit (RF-81S, manufactured by JASCO), is shown in FIG. 10 . The measurements were conducted under the conditions that a detector was TGS, a resolution was 4 cm −1 , a number of times of integration was 32, and a measurement band was 550 cm −1 to 7800 cm −1 .
It was confirmed from Table 2 that the opening size a of each of the microcavities was narrowed substantially in proportion to the bath temperature. In addition, it was found out from FIG. 10 that the characteristic of the wavelength selective heat radiation material varied depending on the opening size a of each of the microcavities and in each of Examples 19, 20, and 21 whose opening sizes a were 3.6 μm, 3.2 μm, and 3.0 μm, respectively, each of the wavelength selective heat radiation materials exhibited excellent wavelength selectivity in a wavelength range of 7 μm or more in particular and had a peak of the emissivity around a wavelength of 6 μm.
For the wavelength selective heat radiation material according to the present invention, in order to simulate heat radiation characteristics of the wavelength selective heat radiation material in which a surface roughness of an upper portion of a cavity wall defining each microcavity (a size of the chipped portion or the thin-walled portion of the upper portion of the cavity wall) was suppressed and in which microcavities each having an aspect ratio larger than 3.0 were formed, a numerical analysis based on a method was performed. The outline of the numerical analysis based on the RCWA method as follows.
Numerical Analysis
The phenomenon in which wavelength selective absorption characteristics are obtained by a periodic surface fine structure has been explained with reference to the absorption by the surface plasmon induced by the periodic structure, the absorption of the standing wave mode by the cavity structure, or the like. However, since it is the complicated phenomenon to which material properties also are related, quantitative explanations have not been made and it is difficult to evaluate the characteristics in an analytical manner.
Analytical Model
Therefore, by using the RCWA method which was a strict solution method for Maxwell's equations, the present inventors et al. determined an optimal form model of the microcavity periodic structure. The optimal form model was a structure in which rectangular microcavities each having an opening size a and a depth d were two-dimensionally arrayed in a vertical and horizontal manner at a period A. These microcavities were formed on one side of an aluminum foil.
Calculation Conditions
The numerical analysis based on the RCWA method was conducted by using the analytical model having the above-mentioned structure, and the simulation evaluation of optical characteristics of the material having a submicron periodic structure on the surface thereof was performed. For the calculation, commercially available simulation software (DiffractMod, RSOFT Inc.) was used. In the RCWA method, since a permittivity distribution of the material is expressed with the Fourier expansion into series, any periodic structure can be analyzed. A geometry and an optical constant (complex index of refraction) are inputted and the Maxwell's equations are strictly solved, thereby allowing a response of an incident wave to be obtained. The RCWA method is a method for analyzing a general three-dimensional diffraction grating problem. The permittivity distribution in a fine structure region is expressed with the Fourier expansion. An analysis accuracy depends on the number of spatial harmonic expansion terms of an electromagnetic field. In the present invention, the analysis was performed with the number of harmonic expansion terms which was 8.
In consideration of up to the eighth order of diffraction, a diffraction efficiency for each order of diffraction was calculated with respect to each wavelength. In the input data, only conditions of an incident wave, a structural profile, and states of optical constants (n, k) of the material were included, and no variable parameters were used in the calculation. The diffraction efficiency for each order of diffraction was calculated by using the optical constants of Al at room temperature, reported in “Handbook of Optical Constants of Solids, E. D. Palik, ed. (Academic Press, Orlando, 1985), p 369-383”.
With respect to the influence exerted on the spectral emission characteristics in a case where the surface roughness Rz of the upper portion of the cavity wall was changed, as in a schematic diagram shown in FIG. 11 , the simulation was performed by setting as a basic form a rectangular microcavity in which a length a of one side was 3 μm, an opening period Λ was 5 μm, a depth d of each of the openings was 10 μm, an opening ratio a/Λ was 0.6, and an aspect ratio d/a was 3.3 and by changing the surface roughness Rz of the upper portion of the cavity wall to (1) 0 μm, (2) 1 μm, and (3) 2 μm.
Calculation Results 1
FIG. 12 is a spectral emission characteristic curve graph showing the results of the numerical analysis for the structure model shown in FIG. 11 , performed in the RCWA method, with a horizontal axis showing a wavelength λ (μm) and a vertical axis showing a spectral emissivity.
When the surface roughness Rz of the upper portion of the cavity wall defining each of the microcavities became larger than 1 μm, a peak of the spectral emissivity in a wavelength range of 4.75 to 5.75 μm in particular was reduced, and therefore, it was difficult to selectively radiate heat radiation light included in an infrared ray transmission wavelength region of a resin member. As a result, it was found out that the surface roughness Rz of the upper portion of the cavity wall defining each of the microcavities was suppressed to be 1 μm or less, thereby allowing the microcavity periodic structure to obtain spectral selectivity suitable for the heat radiation to substantially make the resin member transparent to the infrared light.
With respect to the influence exerted on the spectral emission characteristics in a case where the depth of each of the microcavities having the surface roughness Rz of the upper portion of the cavity wall of 2 μm was changed, as in a schematic diagram shown in FIG. 13 , the simulation was performed by setting as a basic form a rectangular microcavity in which a length a of one side was 3 μm, an opening period Λ was 5 μm, the surface roughness Rz was 2 μm, and an opening ratio a/Λ was 0.6 and by changing the depth d to (1) 5 μm (aspect ratio d/a: 1.7), (2) 10 μm (aspect ratio d/a: 3.3), and (3) 20 μm (aspect ratio d/a: 6.7).
Calculation Results 2
FIG. 14 is a spectral emission characteristic curve graph showing the results of the numerical analysis for the structure model shown in FIG. 13 , performed in the RCWA method, with a horizontal axis showing a wavelength λ (μm) and a vertical axis showing a spectral emissivity.
When the surface roughness Rz of the upper portion of the cavity wall defining each of the microcavities became larger than 1 μm, regardless of the depth d of the opening of each of the microcavities, a spectral emissivity in a wavelength range of 1 to 10 μm was reduced, and a peak of the spectral emissivity in a wavelength range of 3 to 5.5 μm in particular was reduced, and therefore, it was difficult to selectively radiate the heat radiation light included in the infrared ray transmission wavelength region of the resin member. As a result, it was found out that the surface roughness Rz of the upper portion of the cavity wall defining each of the microcavities was suppressed to be 1 μm or less, thereby allowing the microcavity periodic structure to obtain the spectral selectivity suitable for the heat radiation to substantially make the resin member transparent to the infrared light, regardless of the depth d of the opening of each of the microcavities.
With respect to the influence exerted on the spectral emission characteristics in a case where the depth of each of the microcavities was changed, as in a schematic diagram shown in FIG. 15 , the simulation was performed by setting as a basic form a rectangular microcavity in which a length a of one side was 3 μm, an opening period Λ was 5 μm, and an opening ratio a/Λ was 0.6 and by changing the depth d to (1) 2 μm (aspect ratio d/a: 0.7), (2) 4 μm (aspect ratio d/a: 1.3), (3) 7.5 μm (aspect ratio d/a: 2.5), (4) 15 μm (aspect ratio d/a: 5.0), and (5) 32 μm (aspect ratio d/a: 0.7).
Calculation Results 3
FIG. 16 is a spectral emission characteristic curve graph showing the results of the numerical analysis for the structure model shown in FIG. 15 , performed in the RCWA method, with a horizontal axis showing a wavelength λ (μm) and a vertical axis showing a spectral emissivity.
In a region in which an aspect ratio d/a (d: opening depth, a: opening size) of each of the microcavities was less than 3.3, in accordance with an increase in the aspect ratio d/a, an emissivity of the heat radiation light corresponding to the infrared ray transmission wavelength region of the resin member was sharply increased up to approximately 0.85, whereas in a region in which the aspect ratio d/a was 3.3 or more, with respect to a rate of an increase in the aspect ratio d/a, a rate of an increase in the emissivity of heat radiation light corresponding to the infrared ray transmission wavelength region of the resin member was sharply decreased and nearly leveled off in a range of 0.85 to 1.0. As a result, it was found out that the aspect ratio d/a of each of the microcavities was set to 3.3 or more, thereby allowing the wavelength selective heat radiation material exhibiting the high emissivity of 0.85 or more to the heat radiation light to be obtained, to substantially make the resin member transparent to the infrared light.
REFERENCE SIGNS LIST
1 stamp
2 pressing surface
r curvature radius
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An object is to provide a method for manufacturing a wavelength selective heat radiation material in which a surface roughness of an upper portion of a cavity wall defining each microcavity is suppressed or in which microcavities each having an aspect ratio larger than 3.0 are formed. For the wavelength selective heat radiation material, a base material having a mask having predetermined openings tightly adhered to a surface thereof, or a base material in which depressions are previously formed on one surface thereof by pressing a die having projections arrayed so as to correspond to positions of microcavities thereagainst, is subjected to anisotropic etching, thereby providing a wavelength selective heat radiation material in which the surface roughness of the upper portion of the cavity wall defining each of the microcavities is suppressed or a wavelength selective heat radiation material having microcavities whose each aspect ratio is larger than 3.0.
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CROSS REFERENCE TO RELATED APPLICATION
This application claims the benefit of U.S. provisional application Ser. No. 60/605,793 filed Aug. 30, 2004.
FIELD OF INVENTION
The invention relates generally to electrical plugs and more particularly to electrical plugs having movable earth pins.
BACKGROUND OF THE INVENTION
A wide variety of electrical devices typically draw AC power from a commercial source, usually delivered through a wall receptacle or socket, via a corresponding electrical plug.
A conventional electrical plug typically has a pair of conductive power pins for insertion into corresponding female connectors in the socket. The plug typically also includes an earth or ground pin that is inserted into a corresponding female connector in the socket that is coupled to ground. In one or more countries, the earth pin is slightly longer than the power pins and also functions to open a spring loaded shutter in the socket, to allow insertion of the power pins into their respective female connectors in the socket. This safety feature thus requires that an earth pin be included in all plugs even when there is no need for a ground connection.
Battery chargers comprise one type of electrical device whose plugs typically do not require an earth or ground connection. However, to provide the shutter opening function, a dummy ground pin still needs to be provided. Such prior art earth pins are usually in a fixed position on the electrical plug, which makes the electrical plug unnecessarily bulky.
One prior art method for repositioning the earth pin in an electrical plug is to connect the earth pin to a hinge, to enable the pin to be rotated between two positions, an open position and a stored position. The pin is rotated 90° between these two positions about the axis of the hinge.
Consumers of electrical products in recent times have shown a desire for more compact designs. Accordingly, there is a need to reduce the amount of space taken up by an electrical plug when not in use, to enable the plug to be more compact.
SUMMARY OF THE INVENTION
The present invention describes an electrical plug with a slidable earth pin that can be moved into the body of the electrical plug when the electrical plug is not in use. The electrical plug has a slidable earth pin that is positioned in a channel formed in the plug body. The earth pin has a pair of fingers that snap into a first set of grooves in the channel of the plug body to position the earth pin in a first or functional position. The pair of fingers can also snap into a second set of grooves in the channel of the plug body to position the earth pin in a second or stored position. When the earth pin is slid into its stored position, the physical dimension of the electrical plug is significantly reduced, thereby providing a more convenient and compact electrical plug.
Broadly stated, an electrical plug according to the present invention comprises a plug body, a first conductive blade; a second conductive blade; an earth pin having a first finger and a second finger; a channel having a first left snap groove and a first right snap groove for enabling the earth pin to be retained in a first position, and having a second left snap groove and a second right snap groove for enabling the earth pin to be retained in a second position; and wherein the earth pin can be slidably positioned such that said fingers can be manually positioned in respective first snap grooves or in respective second snap grooves. In one embodiment, the earth pin is not removable with a force less than a specified safety norm after the earth pin has been inserted. Advantageously, the present invention provides an electrical plug design that reduces the physical dimension of the electrical plug when not in use.
Other structures and methods regarding the present invention are disclosed in the detailed description below. This summary does not purport to define the invention. These and other embodiments, features, aspects, and advantages of the invention will become better understood with regard to the following description, appended claims and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A–1B illustrates perspective views of a slidable earth pin plug in accordance with a first embodiment of the present invention.
FIG. 2A illustrates a sectional view of the slidable earth pin plug in a first or functional position; and FIG. 2B illustrates a sectional view of the slidable earth pin plug in a second or stored position of the earth pin in accordance with the first embodiment of the present invention with the front panel removed.
FIG. 3 illustrates the assembly of the slidable earth pin plug in accordance with the first embodiment of the present invention with the front panel removed.
FIGS. 4A–4B are detailed perspective views respectively illustrating the slidable earth pin and its sliding contact fingers and the assembly of the slidable earth pin plug in accordance with the first embodiment of the present invention.
FIG. 5A is a detailed perspective view illustrating an earth pin and its sliding contact fingers for a slidable earth pin plug in accordance with a second embodiment of the present invention; FIG. 5B is a perspective rear view and 5 C is a rear view illustrating the earth pin of FIG. 5A assembled in the slidable earth pin plug in accordance with the second embodiment of present invention with the back panel removed.
FIGS. 6A–6B are respective side and front views of the slidable earth pin plug in accordance with the first embodiment of the present invention.
Reference symbols or names are used in the figures to indicate certain components, aspects or features therein, with reference symbols common to more than one figure indicating like components, aspects of features shown therein.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now to FIGS. 1A–1B , there are shown perspective views of a slidable earth pin plug 100 in accordance with a first embodiment of the present invention. The slidable earth pin plug 100 comprises a plug body 110 , a slidable earth pin 120 , including an earth pin blade 124 , and a pair of conductive blades 140 . The slidable earth pin 120 is manually slidable in a vertical direction in a channel 115 formed in the plug body 110 between the pair of conductive blades 140 , as indicted by an arrow 150 in FIG. 1B .
The slidable earth pin 120 in plug 100 can be manually displaced from a first or “functional” position to a second, stored position, as shown in FIGS. 2A and 2B , respectively. In its first position, the slidable earth pin 120 is in a position where the top end of the earth pin 120 protrudes from the plug body 110 a sufficient distance to enable the earth pin blade 124 to be in a functional position, i.e., where it can be inserted into a corresponding female connector in a socket at the same time, or in advance of when the conductive blades 140 are inserted into similar corresponding female connectors in the socket, all as specified by the plug/socket standards of the country in which the plug is to be used. In its stored position, the entire length of the slidable earth pin 120 is preferably within the channel 115 and inside the plug body 110 so that the slidable earth pin 120 does not protrude beyond a top surface 111 of the plug body 120 or beyond the bottom surface 112 of the plug body 120 .
FIGS. 2A–2B also illustrate the means by which earth pin 120 is releasably retained at its respective first and second positions. Earth pin 120 includes first and second fingers 121 and 122 that are compressed slightly when earth pin 120 is first inserted into channel 115 , as described in greater detail below. In its first position, as shown in FIG. 2A , earth pin 120 is retained in channel 115 by a first left snap groove 130 a wherein the first finger 121 is positioned, and by a first right snap groove 130 b wherein the second finger 122 is positioned, such that the earth pin 120 interlocks with the plug body 110 . When the electrical plug 100 is not is use, the earth pin 120 can be manually pushed down the channel 115 to a second or stored position, as shown in FIG. 2B , and held in place by the operation of the first finger 121 snapping into a second left snap groove 135 a and the second finger 122 snapping into a second right snap groove 135 b.
Note that, in its second or stowed position, earth pin 120 provides an indication that an attempted insertion of plug 100 into a socket is incorrect. That is, in its second position, earth pin 120 protrudes out from plug body 110 in the direction of conductive blades 140 in a position that will not align with a socket's ground pin socket hole, thereby preventing the insertion of plug 100 into the socket when earth pin 120 is in this position.
As seen in the views of the present invention shown in FIGS. 1 and 2 , earth pin 120 is prevented from being pushed to a position below the point where first and second fingers 121 and 122 snap into second left and right grooves 135 a and 135 b because of the existence of a narrowing in a slot 126 formed at the front of channel 115 . This narrowing is perhaps best seen at 128 in FIG. 3 . Consequently, as the earth pin 120 is pushed down the slot, the bottom surface of the earth pin blade 124 makes contact with surface 129 of slot 126 , thereby preventing further travel of the earth pin 120 down channel 115 .
As is seen in FIGS. 2A and 2B , fingers 121 and 122 , as well as left and right grooves 130 a and 130 b include surfaces that enable fingers 121 and 122 to be moved out of these grooves with a modest amount of manual force applied to the earth pin 120 in the desired direction of travel.
In FIG. 3 , there is a pictorial diagram illustrating a step in the assembly of the slidable earth pin plug 100 wherein the earth pin is first inserted into channel 115 . In this step, earth pin plug 100 is being inserted into the channel 115 of the plug body 110 , either manually with hand pressure or using a tool or fixture. Once inserted, the upper surfaces of grooves 130 a and 130 b may be shaped in a conventional way known in the art to make it difficult for the earth pin 120 to thereafter be removed from channel 115 in a direction opposite to the direction of insertion.
As perhaps better seen in FIG. 3 , channel 115 includes two sets of snap grooves, a first set comprising first left snap groove 130 a and first right snap groove 130 b , and a second set comprising second left snap groove 135 a and second right snap groove 135 b . The narrowing of slot 126 in the area shown at 128 creates ledges 129 .
A detailed perspective view illustrating earth pin 120 of the first embodiment of the present invention is shown in FIGS. 4A and 4B . As seen in these figures, earth pin 120 includes a vertical section 125 that terminates in fingers 121 and 122 (i.e., the sliding contact surface area) for sliding in the channel 115 of the plug body 110 . The compressive force of fingers 121 and 122 along the sides of channel 115 is selected so as to maintain a preferred level of sliding friction in moving the earth pin 120 up and down channel 115 . The earth pin 120 can even be inserted at a vendor as part of the post-moulding operation. Side and front views of the electrical plug 100 are shown in FIGS. 6A and 6B .
In FIGS. 4A–4B , there are shown perspective views of an edge stop 170 that is preferably formed on the top surface of earth pin 120 . This surface 170 is positioned to ensure that an end user inserts the earth pin 120 a predetermined distance into an electrical outlet (not shown), and no farther.
Turning now to FIG. 5A , there is shown a detailed perspective view illustrating an earth pin 500 and its first and second sliding contact fingers according to a second embodiment of the present invention. FIG. 5B and 5C illustrate the slidable earth pin plug with the rear removed to show the structurally different aspects of earth pin 500 as compared to earth pin 120 described above. The earth pin 500 of the second embodiment is designed with a dual lock approach, where each of the sliding contact fingers has a first set of finger locks 510 that is parallel to a second set of finger locks 512 . The first set of finger locks 510 is used for locking the earth pin 500 in slot 515 by means of ledges 518 of the upper mating grooves 522 , as seen in FIG. 5B . The purpose of the first set of finger locks 510 is to prevent the earth pin 500 from popping out of a plug body 550 after the earth pin 500 has been inserted into the slot 515 in plug body 550 . The second set of finger locks 512 , as seen in FIG. 5C , is used for positioning the earth pin 510 in either a folded position or an unfolded position, as well as providing the user with an indication of proper fitting between the earth pin 500 and the plug body 550 by the sounding of a click when the second set of finger locks 512 has been mated with upper mating grooves 522 or with lower mating grooves 524 . A slot 514 in the earth pin 500 is provided to impart flexibility to an arm 530 having the second set of finger locks 512 .
In a third embodiment of the present invention, the earth pin 120 or 500 is not removable with a force less than a specified safety norm after the earth pin 120 or 500 has been inserted. The finger locks 122 and the grooves 130 a and 130 b in the first embodiment, and the finger locks 510 and the ledges 518 in the second embodiment are designed to implement this safety feature of the third embodiment.
In a preferred embodiment, earth pin 120 or 500 is a non-conductive dummy pin for use in a battery charger or the like where there is no need for a ground connection but where the earth pin 120 or 500 is just needed to open the spring loaded shutter of the socket in which the plug is to be inserted. One of the ordinary skill in the art should recognize that the present invention can be applied to different types of electrical plugs in various regions or countries. One suitable application is on plugs as used in the United Kingdom.
Those skilled in the art can now appreciate from the foregoing description that the broad techniques of the embodiments of the present invention can be implemented in a variety of forms. Therefore, while the embodiments of this invention have been described in connection with particular examples thereof, the true scope of the embodiments of the invention should not be so limited since other modifications, whether explicitly provided for by the specification or implied by the specification, will become apparent to the skilled practitioner upon study of the drawings, specification, and following claims.
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An electrical plug is disclosed with a slidable earth pin that can be manually positioned in a stored position in a plug body of the electrical plug when the electrical plug is not in use. The slidable earth pin is movable in the channel and retained by an interlocking mechanism between the earth pin and the channel on the plug body. The earth pin has a pair of protruding fingers that snap into a first set of grooves in the channel of the plug body in a first position, and that snap into a second set of grooves in the channel of the plug body in a second or stored position. When the earth pin is in its stored position, the physical dimension of the plug is significantly more compact than conventional three pin plugs.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to electronic information processing. In particular, it relates to a method and system for processing a document, which comprises text information, comprising monitoring the occurrence of incomplete time-related citations, in particular the citation of a date, within the text information, and completing said incomplete citation.
[0003] 2. Description and Disadvantages of Prior Art
[0004] Today many kinds of information are digitized and stored in electronic archives, as e.g., in a database. A large portion of such information comprises text, i.e. documents in one or more languages containing words and dates.
[0005] The usability of such electronic archives, however, is dependent of the fact in which way those documents are indexed, as the index serves often for locating a document. Often users need to find documents that are relevant for a particular date or date range.
[0006] A problem is, however, that it is not clear, which date to use for the search, e.g. the date, at which the document was archived electronically, or the date, when the content of the document was generated by its author, or when it was published, etc.
[0007] Content-related dates are often incomplete, e.g., “25 of march”, or “in February this year”. “This year” is a vague time-related citation, the reason why this date cannot be used in prior art for indexing purposes or other purposes, in which it is important to know the precise year of the date.
[0008] A prior art text search method is known from many word processor program applications. It comprises “full text search”. In this case, the whole content of a document is parsed in order to find a useful date indication, which could meet the search pattern condition. The disadvantage is that an incomplete date occurring in the text of a document will not be in the hit list, because the existing technology requires a 1:1 match in the letters and symbols. For example a query “25/3” requires the document to contain the exact sequence of the letters “2”, “5”, “/”, “3”, etc.
[0009] In prior art it is known to transform many different representations of time information into a unified format, in order to make them comparable by the computer. One example for such a canonical time indication can be a language independent date format like “DD.MM.YYYY” as defined in the ISO 8601:2000 standard.
[0010] Also in this prior art approach there is no mechanism to handle or complete incomplete date information: If a date indication relating to or comprised of the text of a document is incomplete, because the year indication is missing, for example, prior art completion methods are limited to an obvious completion, e.g., with the current year indication “YYYY”.
OBJECTIVES OF THE INVENTION
[0011] It is thus an objective of the present invention to provide a method and respective system for processing a document by completing an incomplete date citation automatically and in non-obvious cases, in order to render it usable for selectively storing and/or searching by complete or incomplete dates.
SUMMARY AND ADVANTAGES OF THE INVENTION
[0012] This objective of the invention is achieved by the features stated in enclosed independent claims. Further advantageous arrangements and embodiments of the invention are set forth in the respective subclaims. Reference should now be made to the appended claims.
[0013] In short words, the inventional method is able to complete incomplete citations of a date, within a text of a document by applying a set of predetermined completing rules and using all time information relating to the document. The sources of time information are the text itself, the document “container” and the enclosing applications e.g. a word processor, the computer system, the locale information. Creating an index from a completed date represents a preferred use according to the inventional method after selectively storing, for searching such documents. Thus, e.g. search engines can find such documents in the Internet by entering the completed date as a keyword.
[0014] Further, the present invention is not limited to be applied for the completion of incomplete dates. Instead, it can be used also for completing time indications as e.g., “this afternoon”, “today”, “within the holidays of Christmas”, etc. In this document we use date and time interchangeably to denote an instance or range of temporal entities like date or time.
[0015] Thus, with reference to the appended claims the present invention discloses according to its broadest aspect a method for processing a text document comprising text information, having the steps of:
[0016] a) monitoring the occurrence of an incomplete, time-related citation, in particular the citation of a date, within the text information, and
[0017] b) completing said incomplete citation, whereby the method is characterized by the step of:
[0018] c) automatically completing said time-related citations, or “indications” in the above context, by a supplemental time specification, by applying either one or more of:
[0019] c1) a set of predetermined completing rules establishing for a given incomplete citation prioritizing relationships between other time-related citations within the text information of the same document,
[0020] c2) prior art data mining technology procedures, or
[0021] c3) using context meta information from outside the document.
[0022] It should be understood that the inventional method comprises to look for supplemental time information within and outside the document. “Within” or “inside” means the whole actual content, i.e. the text of the document. “Outside” the document concerns the environment in which the document is stored. This might be a file system, a database table, a physical file, etc. Any of them can be used as a source showing some date indication or time-related information for the purpose of completing dates automatically according to the present invention.
[0023] Date indications in relation to a document are thus located in several sources. They can be found and evaluated according to the present invention in any electronic information, for example:
[0024] In the enclosing application like a word processor,
[0025] In the operating system providing information about access, creation and modification time, e.g. through a file system, logging- or tracing system,
[0026] in form of a send/create/ or receive date in messaging systems, e.g. mail daemons,
[0027] embedded in the document/content itself, ie, from the textual context itself.
[0028] Another important source for completion data is the distance, measured in words or the like, between the incomplete date occurrence and another complete date occurrence or fragment of the incomplete citation in the text. The shorter the distance between one date and another, the more probable is that missing information in one date fragment may be completed with the help of the other date occurrence.
[0029] The above mentioned sources may result in completion rules. Any rule may comprise several kinds of sources for proposing the correct supplemental time information. In fact, many sources may be combined to complete a date fragment. For each source, a rule may be defined, e.g. “fill in the missing year information from the file's creation date”. One can give each rule (or source) priorities or weights in order to determine the most relevant date completion rule.
[0030] With such rules, the completion of dates can be computed automatically with no or little user interaction. With the automatic completion or proposal thereof, the user needs not to deduce the correct complete date out of the given sources for date information. The user can get a list of proposals, i.e., suggestions of supplemental time specification, ordered by probability of fitting according to the priorities or weights of the rules applied.
[0031] The quality of the completion rules is important for the confidence in the correct supplementing date specification. The completion rules may be different from one field of application to the next to produce the best possible results.
[0032] Thus, according to the invention the document can be related to one or more completed dates. It can be linked with other documents that also relate to the complete dates, if desired. That means the linked documents may become a source to complete missing date information.
[0033] Thus, searching for the document with the criterion of the completed date is possible for search engines in networks like the Internet. Links to other documents can then advantageously be used to complete missing date information.
[0034] Another advantageous embodiment comprises the step of creating an index from a completed date, usable for selectively storing and/or searching for the document relating to the completed data citation. Thus, the document can be stored in a data carrier by using an historical index. The document can be found under either the completed date or a date range (as specified by an incomplete date like “in January, 1967”).
[0035] An advantageous feature of the inventive method further comprises the step of providing an index for different types of meta information e.g.,
[0036] a) the date of publishing the document, or
[0037] b) the date of processing the document, or
[0038] c) the date of creating the document.
[0039] In such case a completed date is enriched by an additional information referring to the type of meta information which served as information source to complete the incomplete date. A linkage between those types and the date itself and/or its context allows a weighting of analysis results when presenting multiple completion proposals to the user. Thus, for example, a linkage between “date of processing (in a text processor program) and the incomplete citation “January 1924” may lead to a low probability that the electronic document in question having the incomplete date is processed in the year of 1924 as at this time no computer-based text processors existed.
[0040] A further advantageous embodiment comprises the step of providing a user interface means for specifying a search for documents by means of said indexes. By that a user has an easy and comfortable means for applying said inventional methods.
[0041] Yet another advantageous embodiment further comprises the step of:
[0042] exposing to the user one or more possible time specifications, each accompanied by an indication of confidence, reflecting the value of confidence that a proposed supplemented time specification reflects the truth.
[0043] A value of confidence illustrates usually the probability to the user, that the supplemented time specification is the correct completion of the incomplete time information.
[0044] Thus, the user has an indication of confidence, e.g., 80%, or “greater than 80%”, etc. in the listed dates. He may choose manually one of the listed dates without restriction to the most confidential one.
[0045] Thus, the user receives useful additional information. The confidence value can depend on different factors like the number of appearance of the proposed date in the text and the distance between this date and the incomplete date in the text. Also, the type of source as they were mentioned above, may be selected to influence the value of confidence. The user may also enter a minimum value of confidence as required to produce a proposal for completion. Thus, in a respective document search based on completed dates according to the invention, only such documents will be shown, which have a higher confidence value for the relationship with the specified date.
BRIEF DESCRIPTION OF THE DRAWINGS
[0046] The present invention is illustrated by way of example and is not limited by the shape of the figures of the drawings in which:
[0047] [0047]FIG. 1 is a schematic flow chart representation illustrating the control flow during the completion of an incomplete time citation according to an inventional embodiment,
[0048] [0048]FIG. 2 is a schematic drawing of a table of indexes according to an inventional embodiment, and
[0049] [0049]FIG. 3 is a schematic drawing illustrating the different sources for automatic completion of dates according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0050] With general reference to the figures and with special reference now to FIG. 1, a document containing text is subjected to a preferred embodiment of the inventional method. It should be noted that preceding steps of scanning the text and character recognition have been done already in a preceding procedure, if this should be necessary.
[0051] In a first step 110 an incomplete time citation is found in a document. That can be done with a prior art text parser engine. The incomplete time citation is assumed to be “July, 14”, and the missing indication of the year shall be automatically completed according to the present invention.
[0052] In a next step 130 the inventive tool searches for further time-relevant information. A particular prior art subprogram may do this. This subprogram has preferably incorporated prior art text mining technology for locating and identifying further time citations from the content of the text, i.e., text-embedded time citations. This algorithm may be assumed to find three further time-related citations, which are stored temporarily together with other relevant information, e.g., the distance (in words) from the incomplete citation.
[0053] Thus, the following is assumed to be found within the text:
[0054] a) Jul. 30, 2000, distance: 5 words before,
[0055] b) Oct. 31, 2001, distance: 33 words after,
[0056] c) Jan. 12, 2001, distance: 67 words after.
[0057] Then, further time citations are searched within the above mentioned “meta information”. As the document is assumed to be scanned-in from a paper original, the scan (and store) date of the electronic file within the file system is found by a respective request to the Operating System of the server in use, to be:
[0058] d) Feb. 12, 2002.
[0059] Each found time information a) to d) is transformed into a canonical format e.g. according to DD.MM.YYYY, in step 140 . Thus, the dates can be easily compared by an appropriate algorithm.
[0060] In a subsequent analysis step 150 the inventive program tool compares all this complete time information with the incomplete time citation. The time distance is determined and set in relation to the incomplete date. This may include advantageously to create an ordered list of dates, as mentioned above originating from the enclosing application, from the document container, or from embedment within the text.
[0061] Next, the collecting of relevant facts according to the inventional approach will be described in more detail: With additional reference to FIG. 2, in step 160 (of FIG. 1) the inventive program collects all relevant facts for calculating a confidence value 7 , for each completion proposal based on the respective time information a) to d), see ref. sign 5 in FIG. 2. Such facts can comprise the source of the time information, e.g. the document itself or the related electronic or physical file, and/or the distance to the incomplete time citation in the text, and/or the number of similar or identical appearance in the text, e.g., 5 times “2002” were found in the text”, etc.
[0062] Here is a more extensive list of the proposed mechanism to calculate completion candidates and confidence values:
[0063] A citation E2 qualifies as candidate for the completion of the incomplete time citation E1 depending on the following Criteria c:
[0064] A. Distance-based:
[0065] c1: The number of boundaries that separate textual units between E1 and E2
[0066] textual unites may be:
[0067] words/tokens
[0068] sentences
[0069] paragraphs
[0070] chapters, sections, subsections and the like;
[0071] c2: The number of topic-changes passed when moving from E1 to E2. Each topic might be represented by a set of typical terms or key words. Topics can for example be detected by clustering higher-level textual units such as groups of sentences, paragraphs or sections;
[0072] c3: The number of time expressions occurring between E1 and E2
[0073] that refer to the same year or year/month as E2
[0074] that refer to a different year or year/month as E2
[0075] if E2 appears in a document that is different from the one in which E1 appears but related via links or references:
[0076] c4: The number of links between the respective documents corresponds to the level of indirection;
[0077] B. Other:
[0078] c5: The level of compatibility between E1 and E2, assume E1=D1.M1.Y1 and E2=D2.M2.Y2, * means unknown; an example of this criterion could look as follows:
[0079] D1=D2, M1=M2, Y1=Y2>D1=*, M1=M2, Y1=Y2>M1=M2, Y1=Y2>M1=*, Y1=Y2>Y1=Y2
[0080] c6: The confidence level associated with E2, if E2 has been obtained by automatic completion;
[0081] c7: The frequency of occurrence of time expressions with the same year, year and month within E2's container (document, document collection, or context of use);
[0082] if E2 has been obtained from the context, in which the document containing E1 is used (e.g. database, http header, . . . ),
[0083] c8: The reliability and usefulness of E2's source for providing candidates
[0084] c9: for structured documents:
[0085] The importance of E2 within document (e.g. date stamp in letter)
[0086] Each of these criteria c1 to c9 (i=1, . . . 9) corresponds to a rule of the following type:
CVci ( E 1, E 2)= Mci ( E 1, E 2)* Wci
[0087] where
[0088] CVci is the confidence value for completing E1 on the basis of E2,
[0089] Mci is the measure corresponding to one of the criteria ci above (such as the number of words between E1 and E2),
[0090] Wci is a fixed factor associated with the corresponding criterion ci that defines its relative importance for the calculation of CVci( ) compared with the other criteria.
[0091] Both, Wc and Mc will typically be normalized to a range such as 0 . . . 1 yielding to an overall confidence value within the same range. This ensures that confidence values obtained using different criteria can be compared.
[0092] The set of candidates for completing E1 is calculated by computing CVc(E1, E2)—see reference sign 7 in FIG. 2—for each selected time citation E2=/=E1—see reference sign 5 in FIG. 2 and each applicable criterion C, see step 170 .
[0093] Assuming E1 occurs in a document D1, E2 may be
[0094] a. extracted from D1, or
[0095] b. from a document that can be reached within a certain maximum link-distance from D1 or
[0096] c. from the use context of D1.
[0097] Examples for candidates obtained from a document's use context are:
[0098] Dates as provided by the operating system, e.g. file creation or modification dates,
[0099] Dates from a database in which the document is stored,
[0100] Dates from a workflow system that transports the document to different processes,
[0101] Dates from different documents within the same directory, database or container,
[0102] The process starts with an incomplete date citation with the smallest degree of missing information and tries to complete it with sources that provide the missing information. This date can then be used to further complete other incomplete date citations that may have a higher degree of missing information. That means completed dates can basically become a source for completion.
[0103] The calculation of confidence values can be stopped if one leads to a confidence value that exceeds a certain threshold, after a certain period of time, of when all available criteria have been applied.
[0104] The candidate selected for the completion of E1 is the one with the maximum confidence value. In case the maximum confidence value is shared by more than one candidate, the system uses a conflict resolution strategy to select a single candidate.
[0105] If CVx=max(CVi) for all applicable criteria i, and CVx(E1, E2)=CVy(E1, E3) for E2=/=E3 one of the following conflict resolution strategies can be applied:
[0106] 1. Selecting E2, if Wx>Wy (based on criteria weights—not applicable if x=y), otherwise select E3;
[0107] 2. Defining a criterion z as primary and compare CVz(E1, E2) with CVz(E1, E3). If the former is greater than the latter, select E2, otherwise select E3. Preferably, z should be defined in a way that CVz(E1, E2)=CVz(E1, E3), only if E2=E3. An example for such a z is the distance on the basis of tokens.
[0108] 3. Presenting the list of candidates with maximum confidence value or with a confidence value above a certain limit to the user so (s)he can select a candidate.
[0109] Whether strategy no. 3 is an option at all, depends on the degree of interactivity which is appropriate for the system that carries out the inventive program. If an index is to be created in ‘batch mode’ any type of user interaction will preferably be prevented, while above option 3. may be an appropriate action when the system is used to do ‘historical studies’ on a set of given documents.
[0110] An advantageous way provided by the present invention is to present to the user the plurality of concurrent “preferred” proposals for completing the date, accompanied by the above mentioned probability value, and an optional indication of the source, i.e., a reference (ref.ID) for where the supplementary information needed for completing the incomplete date was found.
[0111] This could be done as follows:
2000 75 % ref. ID 2001 20 % ref. ID 2002 5 % ref. ID
[0112] The evaluation according to the invention may be adapted to any individually different situations to provide better results. For example, the text-embedded information may be more useful to be exploited for completing incomplete dates instead of the first electronic store date. This may apply in situations, for example, in which an archive of historical documents telling stories which lay 300 years in the past is subjected to the inventional method.
[0113] Or, when the creation date of a business letter shall be completed, the time information 5 from the document “container”, the electronic store date, has a higher priority compared to a date occurring in the text content.
[0114] In step 180 the program creates for the incomplete time citation an index table 1 , which is shown in FIG. 2. At least in step 190 this index table 1 of an incomplete time citation is displayed to the user.
[0115] Thus, as a skilled reader may appreciate, such a historical index may be combined with other text search features, and may be enable for setting up quite abstract queries like:
[0116] “Find all documents referring to Mr. X's car accident in December 2000”, or
[0117] “Find all documents referring to “Boston Tea party in 1774”, or the like.
[0118] [0118]FIG. 2 is a schematic drawing of such an index table 1 . It includes an optional type specification 3 for the text-embedded time citations, as e.g.
[0119] Type 1=narrative content,
[0120] Type 2=signature type (to be mostly applied at the end of a letter or document in general),
[0121] Type 3=exceptional status, to be applied in cases in which it is obvious that the incomplete date cannot easily be completed, because it is present in a series of further incomplete dates or complete dates, which cite a “turbulent mixture” of different year indications, for example.
[0122] Said table further includes the proposed supplemental time specifications 5 and respective confidence values 7 . Thus, the user can find the type of each incomplete time citations of a document and all proposed time specifications with their confidence values. The completed date can thus be used as an index as mentioned above.
[0123] With reference to FIG. 3 an example is given illustrating the inventional way of using date indications (see the date-related text in the figure) in relation to a text document originally created in a word processor program and later modified and reviewed by the author, for automatically completing an incomplete date depicted in the text of the document having reference sign 10 . As can be seen from the figure said date indications are thus located in several sources. They can be found and evaluated according to the present invention in any electronic information, for example:
[0124] In the enclosing application like a word processor (see application/database frame),
[0125] In the operating system providing information about access, creation and modification time, e.g. through a file system, logging- or tracing (see the system operating system frame),
[0126] in form of a send/create/ or receive date in messaging systems, e.g. mail daemons (not depicted),
[0127] embedded in the document/content itself, ie, from the textual context itself (see document/content frame).
[0128] A potential area in which the invention can be applied is in enriching document archives with documents which were not stored therein before, due to the lack of a complete date as an order criterion.
[0129] The inventional program can also be useful for search engines in the Internet. The user may look for example for all documents, which comprise the date of e.g., 13.07.2001 with a confidence value of more than 50% in their text content.
[0130] The present invention can be realized in hardware, software, or a combination of hardware and software. A tool according to the present invention can be realized in a centralized fashion in one computer system, or in a distributed fashion where different elements are spread across several interconnected computer systems. Any kind of computer system or other apparatus adapted for carrying out the methods described herein is suited. A typical combination of hardware and software could be a general purpose computer system with a computer program that, when being loaded and executed, controls the computer system such that it carries out the methods described herein.
[0131] The present invention can also be embedded in a computer program product, which comprises all the features enabling the implementation of the methods described herein, and which—when loaded in a computer system—is able to carry out these methods.
[0132] Computer program means or computer program in the present context mean any expression, in any language, code or notation, of a set of instructions intended to cause a system having an information processing capability to perform a particular function either directly or after either or both of the following
[0133] a) conversion to another language, code or notation;
[0134] b) reproduction in a different material form.
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The present invention relates to electronic information processing. In particular, it relates to a method and system for processing a document, which comprises text information, comprising monitoring the occurrence of incomplete time-related citations, in particular the citation of a date, within the text information, and completing said incomplete citation. In order to improve methods of automatic completion of time-related citations in documents, the inventional method completes incomplete citations of a date, within a text of a document by applying (160) a set of predetermined completing rules by using all time information relating to the document. The sources of time information are the text itself, the document “container” and the enclosing applications e.g. a word processor. Thus, e.g. search engines can find such documents in the Internet by entering any complete or incomplete dates. Using an index can optimize and speed up the search for relevant documents.
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This is a continuation, of application Ser. No. 08/464,882, filed as PCT/SE93/01058 Dec. 8, 1993 now abandoned.
FIELD OF THE INVENTION
This invention relates to the production of mechanical and chemi-mechanical pulp with a yield of above 85% from lignocellulose-containing material for The making of paper or board products.
BACKGROUND OF THE INVENTION
Mechanical pulp (e.g. TMP) or chemi-mechanical pulp (e.g. CTMP) is today produced in several different process variations, where steamed chips are refined in disc refiners of various types. At the production of pulps for different printing papers or wrapping materials, of board type, the refining usually is carried out in one or more steps. The first step normally is pressurized, i.e. the refining takes place at temperatures exceeding 100° C., usually immediately below or at the so-called softening temperature (Tg) of the lignin. Heretofore, it was chosen to hold the pressure and temperature in subsequent refining steps on the same level as in the first refining step, or to carry out later refining steps in systems not pressurized, i.e. at a temperature lower than in the initial step, usually at the softening temperature of the lignin or below the same.
The softening temperature of the lignin, which has proved to be an important variable at the refining of chips in mechanical and chemi-mechanical pulp processes, has been determined in the most recent decades in a number of scientific investigations for a plurality of wood types concerned. At the investigations standard equipment and conventional measuring principles for the determination of viscoelastic parameters have been used. For wood, as for other viscoelastic materials, the softening temperature varies with the load frequency at the measurements. At a higher load frequency, the softening temperature increases. At the processing frequencies normally applied in refiners the softening temperature of coniferous wood was determined to be between 125° C. and 145° C., while it proved to be somewhat lower for our most usual hardwood types. The softening temperature can be shifted by the addition of different chemicals. It can be lowered, for example, after impregnation by usual lignin softening chemicals, of the type sulphite.
Relatively high total electric energy amounts are required for producing the aforementioned types of pulp. The production of pulp for newsprint from coniferous wood, for example, can require up to 2000 kWh/ton pulp. In many studies carried out recently with the object of trying to lower the electric energy consumption in the TMP-process, it was found that the initial processing phase seemed to be quite essential for the total energy consumption in different process variants and for the character of the resulting pulp. This seems to apply in spite of the fact that only a small part of the total electric energy consumption in the refining process is used for the fiber separation proper, i.e. for the conversion from chips to free individual fibers (also called defibering).
A fiber separation energy-effective per se as a result of an effective thermal or chemical softening of the chip areas rich in lignin, however, does not prove to be a guaranty that the total energy consumption will be low. On the contrary, it was proved that TMP-process variants, which were initiated with a mild fiber separation poor in energy, often require a high total energy input.
This circumstance seems to be caused by the fact, that mildly separated but unprocessed fibers, which were obtained by carrying out the defibering at temperatures above the softening temperature of the wood lignin, are difficult to fibrillate during the continued working in the refining process. This fibrillation is necessary for increasing the flexibility or the fibers to a desired level and bringing about the fine material characterizing a good TMP-quality. An intensive processing below the softening temperature of the wood lignin initially and during the continued refining process, on the other hand, easily leads to a deterioration of the long fiber content and thereby of the strength properties of the pulp. This is in many cases unacceptable from a quality point of view. A decrease in the energy consumption from an established level in the TMP-process, as a rule, has been associated with a deterioration of certain quality properties of the resulting pulp, for example lower long fiber contant, lower tear strength, lower tensile strength and higher shives content. The present high energy consumption in the TMP- and CTMP-process, therefore, has been necessary for achieving the desired pulp properties.
SUMMARY OF THE INVENTION
It was now found by surprise, that it is possible to combine low energy consumption in a mechanical or chemi-mechanical pulp making process with maintained quality properties. The present invention relates to such a method, where the mechanical processing, for example refining, takes place in at least two steps. According to the invention, the material at its feed into the first processing step has a temperature below the softening temperature of the lignin, and at its feed into at least one subsequent processing step has a temperature exceeding the softening temperature of the lignin. The invention is described in greater detail in the following, with reference to some expedient embodiments and examples with associated FIGS. 1-8.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graph of freeness as a function of energy consumption.
FIG. 2 is a graph of shives content as a function of energy consumption.
FIG. 3 is a graph of the long fiber content of the pulp as a function of freeness.
FIG. 4 is a graph of the tear index of the pulp as a function of freeness.
FIG. 5 is a graph of the tensile index of the pulp as a function of freeness.
FIG. 6 is a graph of the light scattering coefficient of the pulp as a function of freeness.
FIG. 7 is a graph of freeness as a function of the energy consumption.
FIG. 8 is a graph of the light scattering coefficient of the pulp as a function of freeness.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In a TMP-process according to the invention, refining takes place in at least two steps. In the first step the chips are fed into the refiner at a temperature below the softening temperature of the lignin and then are processed under relatively intensive conditions, for example in a double-disc refiner with a speed of at least 1200 rpm or in a single-disc refiner with high relative speed between the refiner discs (at least 1800 rpm, preferably at least 2400 rpm). The energy input in the first step is chosen to be on such a low level, that the long fiber content of the pulp which a.o. yields the potential for the later strength development at the refining, is not deteriorated appreciably. The freenes (CSF) of the pulp after the first step, therefore, shall be high, preferably >500 ml. A subsequent refining step is carried out under conditions where the lignin of the fiber material is well softened. The fiber material then is fed into the refiner at a temperature exceeding the softening temperature of the lignin. In cases when the material consists of coniferous wood not treated with chemicals, the temperature should exceed 150° C., suitably 160° C. and preferably 170° C. When the material is treated with chemicals, the temperature should exceed 135° C., suitably 150° C. and preferably 160° C. As regards an upper temperature limit, temperatures over 200° C. should be avoided, a.o. with regard to dark colouring of the fiber material. The processing frequency preferably can be high (relative speed at least 2400 rpm) at the processing of the well-softened fiber material, which has proved especially favourable from an energy point of view.
The temperature difference between the temperatures of the material at its feed into the first and, respectively, a subsequent processing step should be at least 15° C., suitably at least 25° C. and preferably at least 35° C.
In a process according to the invention fractures and fracture indications in the material initially are guided to layers in the fiber wall not rich in lignin. During the final refining the known fact then can be utilized, that the fiber material can be separated with low energy inputs in areas rich in lignin at temperatures above the softening temperature of the wood lignin. The fractures initially having been guided to areas not rich in lignin, it is thereby avoided to obtain a fiber material with only lignin-covered surfaces which are difficult to fibrillate. This has previously been the great problem when it was tried to utilize refining temperatures above the softening temperature of the lignin at the production of mechanical pulps for printing paper or board products. Fine material from areas between the initial fracture zone and the middle lamina of the fiber rich in lignin also is easily released at temperatures above the softening temperature of the lignin in the later refining step, which can explain the low total energy consumption to a certain freeness (CSF) in this process step and in the entire process according to the invention. The production of fine material otherwise is the most energy requiring part of the mechanical pulp process using conventional technique.
EXAMPLE
Thermomechahical pulp from spruce chips was produced after refining in two steps in a 20" single-disc refiner of a well-equipped test plant. The first refining step (defibering) was carried out after preheating the chips at 115° C. for about 3 minutes, i.e. at a temperature below the softening temperature of the lignin. The refiner was driven by a 3000 rpm motor, in order to ensure that the initial defibering should not take place under too mild conditions. The effect input in the first step was 640 kWh/t, which yielded a pulp with freeness (CSF) 518 ml. In the second refining step the conditions were varied according to the following Table:
______________________________________ Preheating time Refining temperature Motor speedTest min °C. .sup.x) rpm______________________________________A about 1 115 ( < Tg) 1500B " 160 ( > Tg) 1500C " 160 ( > Tg) 3000D " 170 ( > Tg) 3000______________________________________ x) Temperature at preheating and at feed into the refiner
The effect of the varying conditions is shown in FIGS. 1-6 where the most essential pulp properties have been valued, and are commented on as follows:
FIG. 1
shows freeness as a function of energy consumption. It appears that by carrying out the second refining step at temperatures above the softening temperature of the lignin the energy input at refining to a certain freeness can be reduced considerably compared to conventional second step refining at temperatures below the softening temperature of the lignin (compare Tests A and B).The energy reduction will be still greater when, in addition, the speed is increased from 1500 to 3000 rpm (compare Test B with Tests C and D).
FIG. 2
shows the shives content as a function of the energy consumption. It appears that second step refining at temperatures above the softening temperature of the lignin yields a clearly lower shives content at a certain energy input than refining at a temperature below the softening temperature of the lignin (compare Test A with Tests B-D). Also in this case the higher speed yields the most favourable values. This proves to be a further advantage by using the conditions according to the invention.
FIG. 3
shows the long fiber content as a function of freeness. It appears that the long fiber content of the pulp generally can be maintained all the way down to the freeness range 150-200 ml, in spite of the heavy energy reduction at refining according to the conditions of the invention.
FIG. 4
shows the tear index as a function of freeness. It appears that the tear index of the pulp can be maintained all the way down to the freeness range 150-200 ml, in spite of the large energy reduction at refining at the conditions of the invention.
FIGS. 5 and 6
show the tensile index and, respectively, light scattering as a function of freeness. It appears that all tested pulps develop tensile index and, respectively, light scattering coefficient in a similar way when they are valued conventionally against freeness.
In parallel with the tests described and with reference thereto it also was investigated, how energy consumption and pulp quality are affected when a refining process contrary to the conditions of the invention was started with a refining step where the temperature at the feed to the first step refiner is higher than the softening temperature of the lignin. Also in this case the thermomechanical pulp was made from spruce chips after refining in two steps by single-disc refiners. The first refining step was carried out at temperatures above the softening temperature of the lignin in the same equipment which was used previously in the test. The conditions in the first refining step and the freeness after refining with a certain energy input are described in the following Table:
______________________________________ Preheating Refining Motor Energy FreenessTest time, min temp. °C. .sup.x) speed rpm input kWh/t ml______________________________________E about 1 150 ( > Tg) 3000 940 450F " 160 ( > Tg) 1500 900 580G " 160 ( > Tg) 3000 790 415______________________________________ x) Temperature at preheating and feed into the refiner
In a second refining step which was carried out under atmospheric conditions in a 20" refiner, i.e. at temperatures below the softening temperature of lignin, the freeness was lowered to an interesting range for printing paper pulps. The refiner speed in this case was 1500 rpm.
The effect of the varying conditions on energy consumption and light scattering capacity appears from FIGS. 7 and 8, which show freeness as a function of energy consumption and, respectively, light scattering as a function of freeness.
FIG. 7
shows that the energy consumption is considerably higher when the TMP-process is initiated with a refining step at a temperature above the softening temperature of lignin than that obtained with conditions according to the invention (compare FIG. 1).
FIG. 8
shows that the light scattering coefficient is considerably lower when the TMP-process is initiated with a refining step at temperatures above the softening temperature of lignin than that obtained with conditions according to the invention (compare FIG. 6). The pulps produced according to the invention, therefore, are clearly most suitable for use as printing paper pulps, where just the light scattering coefficient must be sufficiently high for achieving the desired optical properties.
The example described proves clearly, that mechanical pulp can be produced with the conditions of the invention at low energy consumption, at the same time as essential properties like shives content, long fiber content, tear strength, tensile strength and light scattering meet high requirements on this type of pulps. The energy consumption at the production of newsprint, for example, can be reduced by about 40% compared with conventional manufacturing methods.
In the process according to the invention, chemicals can be added advantageously after or during the first refining step, in order to avoid dark colouring at the high temperatures above the softening temperature of lignin in subsequent refining steps. The chemicals also can have a bleaching effect.
Examples of such chemicals are sodium sulphite, sodium bisulphite, sodium ditionite, peroxide etc.
According to the invention, the initial processing can be carried out, besides in refiners, also in grinders, compressing screws or other mechanical processing equipment.
In cases when a reject fraction separated from the processed material is subjected to additional mechanical processing, this reject with a temperature above the softening temperature of lignin shall be fed into at least one subsequent processing step.
The invention, of course, is not restricted to the examples shown, but can be varied within the scope of the invention idea.
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A method of producing mechanical and chemi-mechanical pulp with a yield above 85 % from lignocellulose-containing material for the manufacture of paper or board products. The material is subjected to mechanical processing in at least two steps. The material at its feed into the first step has a temperature below the softening temperature of lignin. When the material is fed into at least one subsequent processing step, it shall have a temperature above the softening temperature of lignin.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims priority under 35 USC 119 to German Patent Appl. No. 10 2016 111 352.2 filed on Jun. 21, 2016, the entire disclosure of which is incorporated herein by reference.
BACKGROUND
1. Field of the Invention
[0002] The invention relates to a rollover protection device for a passenger car. The rollover protection device has a supporting device that extends in an upward direction when installed properly. A crossmember is secured on the supporting device and extends in a lateral direction when installed properly.
2. Description of the Related Art
[0003] Many rollover protection devices for passenger cars have been disclosed in the prior art. For example, DE 102 42 832 A1 shows a three-part rollover bar for motor vehicles. A motor vehicle that turns over will roll on the rollover bar. The rollover bar comprises three bar components, namely two bar leg tubes and a bar head of tubular and U-shaped configuration. The bar leg tubes are screwed to the tubular bar head at associated connection points. The rollover bar and the bar leg tubes can be metal die castings, metal forgings or fibre-reinforced plastic parts. The disadvantage of this prior art is that only a small side region is covered. Moreover, there can be an unfavorable ratio of utilization of material to deformation capacity.
[0004] It is therefore the object of the invention to provide a rollover protection device with improved properties.
SUMMARY
[0005] A rollover protection device according to the invention is provided for a passenger car and comprises a supporting device and a crossmember. The supporting device extends in an upward direction when installed properly. The crossmember is secured on the supporting device and extends in a lateral direction when installed properly. The crossmember is of substantially beam that has generous rounded portions, and may comprise a die-cast and/or low-pressure die-cast or forged unit.
[0006] The rollover protection device of the invention has many advantages. For example, the crossmember is of beam-shaped design. Thus, the crossmember can cover a significant width to provide a large contact area, thereby allowing an optimum ratio of utilization of material to deformation capacity. The use of a die-cast unit or a forged unit as a crossmember opens up a large number of design possibilities. Moreover, there is the advantage that the avoidance of sharp edges avoids the need for an additional covering.
[0007] The rollover protection device is suitable for passenger cars, commercial vehicles and especially for cabriolets. There is optimum utilization of the installation space. In all the embodiments, the crossmember may comprise one or more crossmember parts. In this case, each individual crossmember part can be a die casting or a forging.
[0008] The crossmember may comprise at least one recess and, in particular plural recesses. The recesses may extend transversely to a longitudinal extent of the crossmember and can be formed by cold deformation. It is also possible to produce the recesses by a forging method. The recesses also can be produced by a die-casting method or by cold deformation, or can be finish-machined.
[0009] A crossmember provided with plural recesses advantageously combines high stability with a high deformation capacity. As a result, large forces can be absorbed. Considerable energy dissipation by the rollover protection device is made possible while, at the same time, effective protection of the occupants of a passenger vehicle is achieved.
[0010] The recesses may extend substantially in a longitudinal direction of the passenger car.
[0011] The recesses can achieve optimum utilization of material. Minimal and uniform wall thicknesses between the recesses are made possible. It is thereby possible to achieve a continuous and high deformation capacity while, at the same time, high and extremely high forces can be absorbed and dissipated. The total weight can be reduced. Sharp edges are avoided by suitable rounding.
[0012] The individual recesses can be embodied as blind holes or as through holes. In particular, at least two recesses may be arranged directly adjacent to one another. The two adjacent recesses are separated from one another by a single partition wall.
[0013] At least one recess can have a closed bottom. For example, the bottom of a recess can be closed by a cover. However, it is also possible for a recess to receive a continuous bottom at one end during production. The openings of the recesses may be aligned alternately toward the front and toward the rear of the crossmember. Thus, the longitudinal axes of the recesses each may extend approximately parallel to a longitudinal axis of the passenger car. Recesses that are open alternately to the front and to the rear side enable a stable crossmember that can absorb and dissipate enormous forces.
[0014] Each recesses may form a chamber. The chambers can be designed to be open on one side. In particular, a crossmember has a multiplicity of chambers. In one embodiment, the number of chambers is an uneven number. In particular, the number of chambers is between 5 and about 11 and preferably 5 or 6.
[0015] A partition wall may be formed between two chambers. The partition wall may slope relative to the vertical when the cross member is installed properly. A mean angle at the partition wall is preferably between about 0° and 45° relative to the vertical. In particular, the angle is between 5° and 45°. The partition walls alternately may have a particular alignment. Thus, for example, the partition walls can be designed alternately to slope by plus 45° and minus 45° or even by 0° and 45° relative to the vertical.
[0016] The supporting device and/or the crossmember may be adjustable in height. For example, the crossmember can be adjustable in height together with the supporting device. However, the crossmember may be adjustable in height relative to the supporting device. It is then possible to perform adaptation to the respective situation and/or user.
[0017] The crossmember may comprises at least two interconnected crossmember parts. The crossmember parts may be welded to one another.
[0018] At least two crossmember parts may have hook-shaped portions that are interlocked. The crossmember parts can be welded to one another. It is also possible for the crossmember parts to be welded to one another and additionally for each of them to have hook-shaped portions that are interlocked.
[0019] The crossmember may have at least one lateral arched overhang to achieve higher elasticity, improved flexibility and increased contact area.
[0020] The supporting device may comprise at least one vertical member, and a collar may be formed on the crossmember. The collar may fit around the vertical member at the front and rear, and possibly laterally.
[0021] The crossmember may be anchored positively on the supporting device. In this case, the cross member and the supporting device can be connected positively to one another. In particular, the crossmember may engage positively in an inner profile of the vertical member.
[0022] A crossmember that is a forging, die casting of sufficient elongation or a low-pressure die casting provides advantageous rollover protection. Further avoiding sharp edges can eliminate the need for an additional covering.
[0023] The recesses in the crossmember allow optimum utilization of material with minimal and/or advantageous uniform wall thicknesses. This leads to a continuous deformation capacity. The total weight can be reduced.
[0024] Stability and utility can be increased by an alternate wall structure, in which the recesses are alternately open towards the front and the rear.
[0025] Maximum height and maximum width can be achieved. A lateral arched overhang allows better flexibility and a sufficient contact area.
[0026] A collar on the crossmember, at least in the region of an inner profile of the supporting device or of the vertical member, allows improved retention of the crossmember on the supporting device.
[0027] A relatively large number of recesses achieves a considerable weight saving and increased protection for the occupants of a passenger car.
[0028] A positive engagement of the crossmember on the inner profile reduces the number of weld seams.
[0029] Further advantages and features of the invention will become apparent from the illustrative embodiments that are explained below with reference to the figures.
BRIEF DESCRIPTION OF DRAWINGS
[0030] FIG. 1 is a perspective view of a rear side of a rollover protection device according to the invention.
[0031] FIG. 2 is a schematic vertical section along the line II-II in FIG. 1 .
[0032] FIG. 3 is a longitudinal section through a lateral region of the rollover protection device 1 shown in FIG. 1 .
[0033] FIG. 4 is an enlarged detail of an alternative embodiment.
[0034] FIG. 5 is a schematic illustration of another illustrative embodiment of a rollover protection device according to the invention.
[0035] FIG. 6 is a schematic perspective view of a front side of another rollover protection device according to the invention.
DETAILED DESCRIPTION
[0036] FIG. 1 shows a first embodiment of a rollover protection device 1 that comprises a supporting device 3 extending substantially in a vertical direction 2 . The supporting device 3 comprises a vertical member 28 that extends in the vertical direction 2 . A crossmember 5 extends transverse to the supporting device 3 in a lateral direction 4 , and comprises lateral recesses 10 to 12 (nine lateral recesses in this case).
[0037] The recesses 10 to 12 extend substantially parallel to the longitudinal extent of the crossmember and to the longitudinal extent of a passenger car when the rollover protection device 1 and the crossmember 5 are installed in a vehicle. Arched overhangs 27 are provided in the lateral regions, increasing the contact area and also the deformability and load-bearing capacity of the rollover protection device 1 . The radii of the arched overhangs 27 can also be made significantly larger.
[0038] The illustrated crossmember 5 is integral, but can also comprise two different crossmember parts 7 , 8 that are connected to one another at a suitable fastening. The fastening 17 of the rear window penetration element can also be seen here. A conical washer, for example, can be provided as a glass penetration element. It is also possible for a vertical or substantially vertical wall to be formed centrally in order to support the cone in a vertical direction.
[0039] The illustrated recesses 10 to 12 extend from the rear 16 to the front 15 . An end wall can be provided on the front side 15 to increase stiffness. It is also possible for the recesses to be designed as through holes, given careful rounding.
[0040] FIG. 2 is a schematic cross section that depicts the individual chambers 20 to 22 of the individual recesses 10 to 12 .
[0041] FIG. 3 is an enlarged detail, where the connection of the crossmember 5 or the crossmember part 7 to an inner profile 30 of a supporting device 3 can be seen. The supporting device 3 is welded to the inner profile 30 and thus to the supporting device 3 . In this case, the inner profile 30 is welded to the supporting device 3 by a top weld seam 31 . In addition, an anchoring point 33 can form a positive-locking feature on the supporting device 3 over a certain section. It is also possible for an additional weld seam 32 to be provided.
[0042] The crossmember 5 may have a collar 29 , e.g. an encircling collar 29 , as illustrated in FIG. 4 , to achieve a positive connection between the crossmember 5 and the supporting device 3 or the inner profiles 30 of the supporting device 3 . The main weld seam 31 can be provided on the encircling collar.
[0043] An alternative embodiment is also possible where the crossmember 5 has, for example, a hook-shaped portion or at least one hook-shaped portion that interacts with a correspondingly matching hook-shaped portion of another crossmember part 7 or 8 so that the hook-shaped portions result in a fastening overall.
[0044] FIG. 5 shows a variant in which a portion 26 increases the extension height. In the retracted state, the installation space can be used over the entire width.
[0045] The crossmember may comprise two crossmember parts 7 and 8 that are fastened to one another at a fastening point 17 . In this case, hook-shaped portions 25 and 26 can engage one another or can optionally be welded to one another to provide the necessary stability. The crossmember 5 is arranged on the supporting device 3 .
[0046] The crossmember 5 in FIG. 6 has a multiplicity of recesses 10 to 12 . The recesses 10 to 12 extend alternately from the front 15 or from the rear 16 into the crossmember 5 . A single relatively thin wall 23 or 24 exists between two adjacent recesses 10 , 12 . The alternating arrangement of the recesses 10 and 11 has the bottoms 14 of the respective recesses situated alternately on the front 15 and on the rear 16 . As result, a low weight with a high stability is possible. At the same time, a large width and hence a large contact area optionally can be achieved.
[0047] A reduction in the number of weld seams is optionally possible by anchoring or positive engagement between the crossmember and the supporting device 3 or the inner profile 30 of the vertical member 28 .
[0048] Production as a die casting, low-pressure die casting or as a forging makes possible varied and simple machining, thus allowing a saving of effort and costs.
LIST OF REFERENCE SIGNS
[0000]
1 rollover protection device
2 upward direction
3 supporting device
4 lateral direction
5 crossmember
6 die-cast or forged unit
7 crossmember part
8 crossmember part
9 longitudinal extent of 5
10 recess
11 recess
12 recess
13 longitudinal direction
14 bottom
15 front side
16 rear side
17 fastening of the rear window penetration element
20 chamber
21 chamber
22 chamber
23 partition wall
24 partition wall
25 portion
26 portion
27 arched overhang
28 vertical member
29 collar
30 inner profile
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A rollover protection device ( 1 ) for a passenger car has a supporting device ( 3 ) that extends vertically when installed properly. A crossmember ( 5 ) is secured on the supporting device ( 3 ) and extends in a lateral direction ( 4 ) when installed properly. The crossmember ( 5 ) is of beam-shaped design and comprises a die-cast, low-pressure die-cast or forged unit ( 6 ).
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CROSS REFERENCE TO RELATED APPLICATIONS
Applicant claims priority under 35 U.S.C. §119 of German Application Nos. 198 43 046.9 and 198 43 047.7 both filed Sep. 19, 1998. Applicant also claims priority under 35 U.S.C. §120 of PCT/DE99/02903 filed Sep. 9, 1999. The international application under PCT article 21(2) was not published in English.
DESCRIPTION
The invention relates to a method for the pretreatment, specifically for the desizing and boiling off as well as bleaching, if need be, of cellulose materials, by which a treatment mixture of a pretreatment agent containing per-compounds such as hydrogen peroxide is applied to the cellulose material and caused to act as intended in the pretreatment. Furthermore, the invention relates to a method for applying the treatment agents in the reactive dyeing and dye fixation of cellulose material, by which the material is pretreated, specifically desized, boiled off and/or bleached before the dye is fixed.
The term “web-shaped cellulose material” is understood to relate to flat textile structures made of cellulose, including cotton, viscose, regenerated cellulose as well as its mixtures among each other, and/or made of synthetic fibers. The method is intended to be applied primarily in conjunction with flat textile structures such as woven or meshed textile structures; however, its application in connection with threads or ribbons of thread is possible as well. Suitable per-compounds, briefly “per”, which split off oxygen in solution preferably by decomposition of hydrogen peroxide, within the meaning of the invention are, for example perborates or percarbonates. The respective treating agent is preferably applied by immersion in a bath containing the treatment agent.
The process steps desizing and boiling off as well as bleaching, if need be, are part of the preparation process, the so-called “pretreatment” in the finishing of textiles. The purpose of desizing is to remove all substances that were previously applied to the fiber in the sizing process. Various methods of desizing are available that conform to the sizing agents employed in the given case. Starch-containing sizing agents can be desized with the help of enzymes; in other cases, oxidative desizing is required. The natural impurities of cotton such as fat, waxes, pectins etc. render such a cellulose product hydrophobic and are therefore removed as “dirt” in a generally alkaline boiling-off process, for example with sodium peroxide.
Following desizing and, if need be, boiling off, many textiles have a undefined yellowish color impression that is often removed prior to subsequent dyeing by bleaching if a defined color shade is to be obtained. In the treatment of cotton and other native as well as regenerated cellulose fibers, hydrogen peroxide bleaches, among other things, are almost always used in conjunction with sodium hydroxide and other chemicals.
In many of the known desizing, boiling-off and bleaching processes, a separate plant, for example a desizing, a boil-off and a bleaching plant is required for each of the process stages. Such plants are frequently not operated continuously because dwelling times of several hours are to some extent required for permitting the respective chemical to act. The expenditure in terms of machines, space and operating costs is consequently substantial. Another drawback is the time expenditure of at least 1 hour needed in most cases in connection with the usual dwelling times. If the work is carried out at high temperatures in order to reduce the process, the energy costs rise accordingly.
A combined desizing, washing and bleaching process for raw textiles made of cotton, which is carried out continuously, is described in CH 560 789. In said process, the cellulose material is wetted with an aqueous solution that contains as important components alkali metal hydroxide as well as per-compounds such as hydrogen peroxide and peroxide phosphate. The material is heated to a treatment temperature of about 80° to 135° C. At treatment temperatures of 100° C. and normal pressure, the treatment vessel contains 100% by vol. steam. At the temperature limit of 80° and normal pressure, which is specified in the prior art, almost 100% by vol. steam is reached in the treatment vessel as well. Following the heat treatment, the material is washed. Short treatment times of down to 1 minute are possible only at 135° C. and 100% by vol. steam in the pressure vessel and consequently only discontinuously.
During the known steam treatment of the material loaded with the pretreatment agent at approximately 100% by vol. steam, the moisture content of such material is maintained approximately constant in accordance with the steam content of the treatment chamber. However, the per-compounds, in particular hydrogen peroxide, contained in the pretreating agent decompose during that time in accordance with the relatively high temperature. As a result, the content of per-compounds in the (approximately constantly moist) textile material is constantly reduced. As the concentration of the per-compounds decreases, their desired pretreatment effect (per time unit) is diminished as well. Therefore, in the known art it is necessary to work with relative high excess amounts of per-compounds. According to CH 560 789, substantial treatment times are nonetheless needed if the work is not to be carried out discontinuously in pressure vessels at temperatures of close to 135° C.
However, in the steam atmosphere (100% by vol. steam) for which provision is made in the aforementioned patent CH 560 789, the amount of per-compound used is not nearly completely degraded. This, however, is not permissible because the reactive effect of the per-compounds would otherwise increasingly drop toward the end of the pretreatment process (and the reaction time required for the pretreatment would become increasingly longer). Therefore, the per concentration still remains so high at the end of the pretreatment that the material has to be washed after the treatment has been completed. This applies specifically if such treatment is followed by a subsequent dyeing process because the dyestuff can be damaged by per-substances.
For a discontinuous peroxide bleaching step preceding the dyeing of cellulose material, it is proposed in DE 39 06 769 A1 to first add glyoxal or glyoxalic acid to the bath to be used for dyeing. Such substances are expected to neutralize those per compounds that remained on the material from the peroxide bleach, if possible without any interconnected washing step. The additional chemicals lead to contamination of the waste water accordingly.
A very similar process for dyeing in reactive dyestuffs after a bleaching process is disclosed in U.S. Pat. No. 5,378,245. The treatment bath used for bleaching contains hydrogen peroxide. The bath is permitted to act on the material for 45 to 60 minutes at 70 to 120° C. As in the aforementioned documents CH 560 789 and DE 39 06 769, the bleaching process thus takes place at almost 100% by vol. air humidity in the treatment chamber and without any drying of the material. The hydrogen peroxide components accordingly remaining on the material with the wet bleaching process used in the present case as well, are therefore neutralized with a reducing agent before the dye is applied in order to protect the dyes against the peroxide.
DE 31 24 961 A1 describes a discontinuous process for simultaneous dyeing and desizing. This is a cold-dwelling process in which dyes and desizing agent (amylase) as well as soda are added to the treatment bath. Following immersion and squeezing off and a bath absorption of about 70%, the textile material is rolled up and, wound in a plastic foil, stored for 24 hours at about 20° C. while slowly rotating. The material is subsequently passed through a boiling soap bath, among other things. If the material has to be bleached, the soap bath may contain the bleaching hydrogen peroxide because the simultaneous dyeing and desizing process cannot be combined with the bleaching step, as the bleaching agent would damage the dye.
In a process known from WO 97/14839 for fixing the dyestuff in a reactive dyeing process, the material impregnated with a dye bath containing the reactive dye is treated in an air dryer with atypically moist drying air. The moisture content and the dwelling time of the material in the air dryer are adjusted in such a way that the desired reaction of the dye with the cellulose fibers takes place while the material is passing through the dryer. In the known art, the air dryer is operated with the substantially steam-loaded drying air in order to achieve an optimal dyeing yield with minimal use of chemical adjuvants.
The invention is based on the problem of providing a pretreatment method that permits a continuous operation throughout; which substantially combines the pretreatment in a treatment aggregate, or type of aggregate; which does not require special neutralizing agents for eliminating residues of per-compounds, if any; and which requires—without excess pressure—shorter processing times for the treated textile material vis-à-vis the prior art. A further problem is to reduce the consumption of the overall amount of chemical adjuvants, in particular alkali substances required for the pretreatment and fixation of the dyestuff in the reactive dyeing process, without impairing the success of the pretreatment or the dyestuff yield.
The solution as defined by the invention for the method specified above for the pretreatment, in which per-compounds are employed, is described in claim 1 . Decisive is in particular the fact that the per-compounds are expelled from the cellulose material by continuous drying with circulating air. A method of reactive dyeing and dye fixation in connection with cellulose material is also specified. A number of improvements and further developments of the invention are described in the dependent claims.
The achievement made possible by virtue of the invention is that the water content in the textile material during drying is reduced to about the same degree and thus at about the same rate as the proportion of per-compounds, in particular hydrogen peroxide is decomposed or consumed at the respective treatment temperature. This means that according to the invention, the concentration of the per-compounds in the bath that are still present in the material, is to be approximately constant. It is, in this conjunction, within the scope of the invention to control the rate of decomposition of the per-compounds, for example in accordance with the way in which such compounds are charged and/or in accordance with the treatment temperature, for example by adding stabilizers or destabilizers, in a way such that the rate of decomposition and the rate of drying are approximately the same up to close to about complete decomposition or consumption of the per-compounds. The relative effect of the per-compounds does practically not change throughout the entire actual pretreatment process because of their approximately constant concentration on the material. The actual pretreatment process, which can be followed by further drying of the material, can be considered completed once the per-compounds have completed their function.
Since the amount of water in the treatment bath absorbed by the material decreases, the effect of the other pretreatment substances, for example alkalis, which are only consumed in the course of the treatment but do not degrade on their own, practically even increases. The approximately constant per concentration and the alkali concentration, which may be increased under certain circumstances, etc., lead to the fact that with the procedure as defined by the invention, the pretreatment takes place substantially quicker than it does in connection with conventional methods.
Furthermore, the amount of per compounds used can be dimensioned in such a way that such per compounds, with approximately constant concentration on the material at the start, are consumed at the end of the pretreatment process down to an absolutely unnoticeable measure. Washing, for example prior to dyeing, because of any residues of the per-compound that might be present, is therefore not required. In the known art, on the other hand, washing or neutralizing has to be carried out because the concentration of per-compounds in the treatment bath contained within the material constantly decreases, and the per-compounds have to be added (at the start) in excess amounts if an effect is to be noticeable near the end of the process at all.
In general, the method as defined by the invention can be carried out if moist-hot, but not wet-hot drying air is used. The drying air employed according to the invention should contain only as much moisture as required for the drying rate of the material and the decomposition rate of the per-compound used to be approximately the same. A drying air satisfying these conditions is referred to as “moist-hot” within the scope of the invention.
The pretreatment as defined by the invention is preferably carried out in an air dryer operated with circulating air, whose “moist-hot” drying air has a steam content in particular in the order of magnitude of about 30% by vol. steam, which per se prolongs the drying rate. Said measure may vary considerably, for example by ±10% by vol. points. Therefore, provision is made for an atypically operated air dryer that is operated not in the usual way with as little water vapor content as possible, but rather with a relatively high water vapor content in the circulating air. However, the water vapor content should be adequately low for the constant drying to take place in the course of the treatment process, and a dwelling time within the circulating air of from 2 to 5 minutes will suffice for drying if the temperature of the circulating air is within the order of magnitude of 100° C. and higher.
The lower limit of the duration of the treatment of about 2 minutes specified above is defined by the time in which the component of per-compounds, e.g. hydrogen peroxide has been consumed or chemically decomposed to a measure that is no longer interfering, depending on the level of the treatment temperature. The upper limit of the treatment duration is determined by the quality, in particular by the weight of the treated material. With lightweight material, an overall treatment time that is about equal to the consumption or decomposition time of the per-compounds, may suffice. The actual pretreatment is completed once the minimum time specified above has elapsed. This means that if no further drying of the material is required, said pretreatment can be terminated.
According to the invention, a cellulose material loaded with a treatment bath containing pretreatment agents is to be continuously passed (generally following immersion in the pretreatment bath) through the moist-hot drying air and is there simultaneously desized, boiled off and, if need be, bleached by the moist heat acting on the pretreatment agents, with continuous drying of the material in spite of the moisture. All reactions desired in the course of the pretreatment for the possibly various types of pretreatment can be carried out at the same time in the moist hot drying air.
It was found to be favorable if all pretreatment agents are applied to the material at the same time in one single pretreatment agent bath. The cellulose material can be completely prepared in the moist-hot drying air for a continuously following dyeing process downstream. However, the bath containing the respective pretreatment agents can be applied to the cellulose material in a number of steps as well. This is preferably accomplished by continuously impregnating or immersing the material in one or several padding machines arranged one after the other and each followed by a calender downstream. An air passage providing in particular for a dwelling time of a few ten seconds can be interconnected between each two padding machines, for example for the purpose of superior wetting. The calendering effect can be adjusted in such a way that the material is received in the air dryer with the usual residual moisture values.
An advantageous device for carrying out the pretreatment method as defined by the invention comprises at least one treatment padding machine, an air dryer, as well as washing and drying plants. A chamber with a material inlet and outlet as well as with controllable exhaust-air volume, controllable circulating fan and with adjustable steam injection can be provided in the form of the air dryer, i.e. the latter being the pretreatment device. In the chamber, provision has to be made for a climate-measuring device. connected to controlling means for regulating the exhaust air volume and the steam injectors for adjusting a predetermined steam content in the circulating air.
It is within the scope of the invention if the drying chamber or air dryer also comprises two or more individual aggregates which, however, act as one single device in the result. The operation as defined by the invention in the air defined as moist-hot can be referred to as “steam drying”. According to a preferred solution, such steam drying is carried out in a so-called hot flue.
The basis of the method as defined by the invention for the pretreatment of cellulose material is that the material, after having been acted upon by the respective treatment bath, dwells for a few minutes, e.g. 2 to 3 minutes, preferably in a padding machine, at 110° to 150° C. (depending on the weight of the material), with a steam content in the air of the dryer (with continuous passage through the latter) in the order of magnitude of 30% by volume. This suffices for a complete pretreatment of the cellulose material. No pressure vessel is required because of said relatively low water content, so that the process always can be carried out continuously.
It is surprisingly possible to basically employ the reactive dyestuff fixation device described in the aforementioned WO 97/14839 for carrying out the pretreatment method as defined by the invention. By adapting the treatment bath to the objectives of the pretreatment, and by drying the material at a rate approximately conforming to the consumption and decomposition rates of the per-compounds, it is principally possible to employ the known reactive dyeing device as the pretreatment device. Said solution is remarkable to the highest degree in that the numerous, partially discontinuously operating machines interconnected between the padding machine and the washing machine in the known pretreatment installations are replaced by one single type of machine, namely the air dryer. Based on the temperature, the pretreatment as defined by the invention is carried out in this conjunction at a substantially higher processing rate than ever known before, and in continuous manner throughout. The amount of per-compounds used practically acts until the last moment of the actual pretreatment process with (based on the material) an absolutely almost unchanged reaction rate. Neutralizing agents (acting against the per-compounds) are not required.
According to the further invention, a method for applying the treatment agents in the reactive dyeing and dye fixation of cellulose material, in which the material is desized and boiled off and, if need be, bleached, or briefly pretreated, consists in that the material received from the pretreatment stage is impregnated in the unwashed condition with a reactive dyestuff bath and the dye is then fixed. Said part of the invention can be referred to as the “dyeing part” in order to distinguish it from the first part, which is the “pretreatment part”.
As a rule and preferably, the pretreatment part as defined by the invention and the dyeing part as defined by the invention are combined in a plant installation through which the material is passed continuously. If need be, the dyeing part can be set up between the air dryer and the washing plant of the pretreatment part. However, an independent application may be basically advantageous within the scope of the invention as well, that is to say, after the pretreatment part, the material can be washed as well as possibly dried and processed or treated further in some other (known) way. The dyeing part of the invention, too, may follow some conventional pretreatment plant upstream and exploit alkali residues originating from the previous stage, as long as no interfering per-compound residues are left over (in the material to be dyed).
In the dyeing part of the invention, the chemical substances, particularly alkali, supplied for the pretreatment process and still present in the material when the latter exits from the pretreatment stage, are employed for the mechanism of the reaction in the reactive dye fixation process. This means that in the dyeing part, the substances and excess treatment agents detached from the material in the pretreatment part of the invention can remain on the material and can be washed out only at the end of the dye fixation process to the extent such substances and agents were not consumed already in the dye fixation process. Finally, therefore, the material coming from the pretreatment stage can be continuously and directly passed into the reactive dyestuff bath in the “as-is” condition, possibly also undried, if need be. However, the bath carried along from the pretreatment stage may no longer contain any amounts of per-compounds damaging the dyestuffs.
The core of the dyeing part of the solution as defined by the invention consists in that the chemical substances—with exception of the per-compounds—already applied for or during the pretreatment are employed not only for the physico-chemical process taking place in the pretreatment stage, but are used a second time during the fixation of the reactive dyestuff.
In the dyeing part of the invention, the (pretreated and unwashed) material, when it comes into contact with the reactive dyestuff bath, already contains the alkali etc. required for the chemical process of dyestuff fixation carried out in the device according to the aforementioned WO 97/14839. Such alkali may be diluted in the material in the preceding pretreatment; however, even a weak alkali suffices for the dyestuff fixation process. In the washing process (followed by drying, as a rule) following the reactive dye fixation process, excess amounts of treatment agents and reaction products such as dirt, including any residual amounts of alkali, originating from both the pretreatment stage and the dyeing stage are separated.
Since the amounts of alkali or the like used in the pretreatment part according to the invention are caused to act also in the dye fixation process, the amount of chemical adjuvants that have to be added to the respective dyestuff bath, is substantially reduced. The amounts of alkali etc. loading the waste water are substantially reduced because of such double function.
However, the dyeing part of the invention still offers an additional advantage because if not only the washing step conventionally following the pretreatment but also the drying step can be dispensed with, equipment and energy expenditures are saved accordingly. A joint washing and drying plant is then associated with the pretreatment and dyeing stages. Therefore, in addition to the advantage of saved amounts of alkali and reduced contamination of the waste water, the benefits of reduced equipment expenditure (a complete washing and drying plant is omitted) and accordingly reduced energy expenditure are gained.
A few details of the invention are explained in the following with the help of the schematic representation of an exemplified embodiment. In the drawing,
FIG. 1 shows an overall pretreatment installation as defined by the invention.
FIG. 2 shows a modification of the equipment according to FIG. 1; and
FIG. 3 shows a pretreatment plant with a continuously following dyeing plant.
According to FIG. 1, an installation as defined by the invention for the pretreatment of cellulose material, for example terry cloth, may basically comprise four aggregates, specifically a padding machine 1 for the metered application of a pretreatment bath to the material, a hot flue 2 for steam-drying the material loaded in the padding machine, a washing plant 3 located downstream of the hot flue 2 , and a drying plant, e.g. a hot flue, a cylinder dryer or a stretching frame, following the washing plant downstream. The web-shaped cellulose material 5 to be treated has to continuously pass through said aggregates 1 to 4 in the transport direction 6 .
First, in the padding machine 1 , the material 5 is immersed in a pretreatment bath 7 present in the bath vat 8 , said bath being of the type usually employed for desizing, boiling off and bleaching. From the bath 7 , the material travels via a mangle 9 into the hot flue 2 , where provision is made with the help of known measures as described, for example in WO 97/14839, that after exiting from the mangle, the material 5 loaded with, for example 100% residual moisture, is maintained from the material inlet 10 to the material outlet 11 of the chamber 12 of the hot flue “moist hot” in such a condition that the systems “material”, on the one hand, and “applied pretreatment bath” on the other, remain ready for the reaction in the desizing, boiling-off and bleaching processes, which means that in the course of the actual pretreatment process, the drying rate of the material is approximately equal to the decomposition rate of the per-compounds.
If the individual pretreatment agents may not or must not be mixed with each other in one single treatment vat, or if adequate wetting of a material by passing it immersed through one single padding machine poses problems at the processing speed desired in the given case, it may be favorable according to FIG. 2 to connect two or more padders 1 a and 1 b one after the other and to guide the material 5 through a mangle 9 a and 9 b after exiting from the pretreatment bath 7 a and 7 b, respectively. Dehydration is then preferably carried out to a greater extent in the first mangle 9 a than in the second mangle 9 b, so that as little pretreatment bath 7 a as possible is carried from the first vat 1 a into the bath 7 b of the second vat 1 b. An air passage 13 , for example providing for a dwelling time of from 20 to 40 seconds, may be interconnected between the two padders 1 a and 1 b in order to permit the pretreatment bath of the first vat 1 a to act before the material 5 runs into the second vat 1 b.
As basically shown in FIG. 1, it may be favorable for carrying out the method as defined by the invention if the chamber 12 of the air dryer 2 is equipped with a controllable exhaust suction channel 14 as well as with the controllable steam injectors 15 , and if a climate-measuring device 16 is arranged in the chamber, such measuring device being connected to the means for controlling the exhaust suction channel 14 (volume of the exhaust air) and the steam injectors 15 . In this way, it is possible to adjust a preset minimum steam content of the circulating moist-hot air.
FIG. 3 explains the principle of a combined pretreatment and dyeing installation as defined by the invention. A web-shaped cellulose material 22 moving in the transport direction 21 is passed through a pretreatment agent applicator device symbolized as the padding machine 23 , with a mangle 24 located downstream of the latter. Said applicator device can be designed like in the pretreatment part as defined by the invention, for example like in FIG. 1 or 2 , or it may be realized also in the conventional manner, in which case it comprises one or more stages for applying the respective pretreatment agent 25 to the material 22 . Pretreatment agents containing alkali particularly in the form of sodium hydroxide or the like alkali compounds, are employed for desizing, boiling-off and/or bleaching. An addition of alkali is required for the active physico-chemical system of the pretreatment, as a rule. The material 22 loaded in the padding machine 23 in the described manner is then received in some type of a single- or multi-stage pretreatment plant, but preferably in the pretreatment installation 26 as defined by the invention.
The material 22 pretreated in the installation 26 or the like is then passed into a dye applicator, which is symbolized in the drawing by the padding machine 27 with the dye bath 28 and the mangle 20 located downstream. In the dyeing part of the method as defined by the invention, the dye bath 28 contains the reactive dyestuff (and wetting agent, if necessary). However, no fresh alkali is required. The alkali (possibly including other chemical adjuvants) required for the reaction in the dye fixation equipment 30 downstream should deliver the material from the pretreatment installation 26 already in the form of a reaction residue (conventionally to be washed out). However, no residues of per-compounds should be present any longer in the material.
Therefore, when the material 22 exits from the second padding machine 27 via the mangle 29 in the direction of the dye fixation equipment 30 , it is loaded also with the reactive dye bath (metered) in addition to the substances that remained from or originated in the pretreatment process. The dye fixation accordingly takes place with the utilization of the alkali etc. already used previously (in the pretreatment).
The dye fixation can be followed by a washing plant 31 , for example the washing plant 3 of FIG. 1, where, if necessary, all substances that could interfere with the further finishing of the material 22 are washed out. This includes in particular the dissolved or converted sizing agents, released dirt, excess dyestuff, and the unused or converted adjuvants. The material 22 purified in the washing plant 31 may finally pass through a dryer 32 and can then be admitted to further processing, or it can be stored.
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The invention relates to a process for preparative and reactive dyeing of cellulose material. In order to shorten the process time of conventional preparing agents and continuous operation, to make superfluous neutralizing agents for removing excess peroxy compounds as well as to reduce the mechanical equipment required vis-à-vis prior art and to reduce the use of chemical agents, the cellulose material soaked with the treatment liquor is continuously dried with pulsated air at approximately the same disintegration rate as the peroxy compounds thus used. Alkali remaining in the material from pretreatment which remained in the material is used for dyefixing said material.
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RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional Application No. 60/856,828, filed Nov. 6, 2006. The entire teachings of the referenced application are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] Medical delivery devices employing a pen delivery device syringe with a replaceable hypodermic pen needle are well known and used to meter the proper dosage of insulin and other medications, such as to self-users who administer their own injections. While pen delivery device syringes are typically provided with enough insulin for several doses, the removable and replaceable needles are intended for single use only. For safety and sanitation, it is recommended by the pen delivery device manufacturer's FDA approved Package Insert, that the needles of such existing devices should not remain attached to the pen delivery device syringe after use, and should be used only once, then discarded. This creates the need for a new sterile needle whenever and wherever the next injection is necessary, and the need to carry additional needles with the delivery device.
[0003] To use a needle for the first time, it must be unsealed, screwed to the pen delivery device syringe, the outer cap must be removed, and then the inner cap must be removed, leaving possible the inhalation of air into the pen delivery device syringe if the needle is not removed between injections. The outer cap is used to remove the pen needle, and is manufactured so as to not allow the needle to penetrate the cap. The inner cap is not meant for reuse of any kind. If the inner cap is used to recap the needle the needle can penetrate the inner cap and cause a stab wound. But since many users are inclined, for reasons of economy of out of laziness, to leave a pen needle attached to the pen delivery device syringe and re-use the pen needle, a serious safety hazard results even in a storage system that contains the pen needle outer cap to protect from inadvertent pricking. This safety concern and the inclination to disobey recommended needle replacement instructions also creates the need for a system that forces users to separate the needle from the syringe after each use.
[0004] Containers are well known for carrying both delivery devices and extra needles, such those sold by Eli Lilly and Company of Indianapolis, Ind., which is depicted schematically in FIGS. 1A and 1B of this disclosure. As seen in FIGS. 1A and 1B , this syringe 120 includes a dust cover 122 which is large enough to hold a new needle 141 without a protective case. As will be shown in later drawings, such as FIG. 2B , such needed are normally provided in a protective needle case, and intended to be stored and protected in the dust cover 122 in a sealed state, removed, unsealed, and affixed to the pen delivery device syringe just prior to use, and then removed and discarded after use. But rather than provide a means to force users to remove and discard used needles, these systems actually inspire users to leave the used pen needles attached to the pen delivery device syringe by providing a dust cover with sufficient space to fit back onto the syringe with the used needle still attached.
[0005] For use, a patient carrying the pen delivery device syringe 120 of FIGS. 1A and 1B and finding himself in need of an injection would first remove dust cover 122 , which may be affixed by a snap-fit or by threading, find a pen needle in a pocket, purse or medicine cabinet, remove the pen needle's protective foil cover, attach the needle to the pen delivery device syringe, remove the outer cap of the pen needle, remove the inner cap of the pen needle and then give themselves an injection with the attached pen needle. A dose of insulin is then administered by injection to the patient. The used needle should finally be, replaced into its protective outer cap casing 140 , and discarded.
[0006] It should be appreciated however upon inspection of FIG. 1A that there is plenty of room within dust cover 122 to receive again the pen delivery device syringe with the used needle left still attached without its outer cover, and it should be appreciated how such a possibility increases the likelihood that such an improper practice my be followed by many forgetful, frugal, or lazy patients.
[0007] Additionally, many users may require more than a single dose of insulin during the day or may require a low does that allows them to use the pen delivery device syringe several times, and it is preferred that several spare needles be on hand for each syringe. But existing syringes, such as that shown in FIGS. 1A and 1B have space to hold only a single new needle, without the outer cap, thereby forcing users to carry spare needles separately or inspiring them to improperly leave used needles attached to the syringe for dangerous re-use and the possibility of inhalation of oxygen into the syringe.
[0008] It is well known that many pieces of apparel, purses, pocket books, portfolios, brief cases, and similar items worn or carried during everyday travels have receiving means specifically shaped to accommodate pens and pencils. For various reasons including optimized carrying in such receiving means, the aforementioned prior art pen delivery device syringes are housed in containers shaped like typical writing pens, generally having a tubular housing with a blunt bullet-shaped tip. The bullet shaped tip is safer than a sharply pointed tip, while still pointed enough to aid in the insertion of the housing into a pocket or such. And since most diabetics prefer to remain discreet about their illnesses, the ability of the pen-shaped device to be carried and stowed discreetly is of significant value. A pen-shaped housed syringe is as discreet and easy to carry as ordinary pens and readily received within typical pen receiving means.
[0009] The lack of a storage location for more than a single replacement needle on or within the housings of such pen delivery device syringes has forced their users to carry accessory packs or other containers to hold their spare needles, which are not discreet or as readily stored and carried as the pen-shaped device itself, and which further inspire users to improperly re-use pen needles. Users who do obey the recommendations of syringe manufacturers and remove needles after each use are forced to carry their spare needles separately and less accessibly, and often complain about misplacing or forgetting needles and about the inconvenience of managing two or three different objects (syringes, needles, and containers). The benefits of the discreet and convenient pen-shaped devices are often lost due to such multiple object management.
[0010] Additionally, in the panic of an emergency, users have been known to fumble while looking through a purse or pockets for a lost spare needle which was unable to be stored with the delivery device or in the pen receiving means of the purse or apparel, thereby losing critical time for administering their medication.
[0011] There exists therefore the need for a compact and pen-shaped storage system for complimentary use with or for containing a pen-shaped syringe and one or more spare needles, which is capable of being received and carried as an ordinary pen, and which keeps both the delivery device and pen needle for instant access as needed, yet which forces the pen delivery device syringe and needle to be separated both before and after use.
[0012] Additionally, because people with diabetes are the primary users of such medical delivery devices and typically need to monitor their blood sugar levels with the use of disposable self-monitoring blood glucose strips, and because these strips should be kept in an airtight container, there exists the further need for such a compact and pen-shaped storage system which may also contain such strips or other related accessories.
SUMMARY OF THE INVENTION
[0013] The present invention may be embodied as a pen-shaped storage system for complimentary use with a variety of devices including pen delivery device syringes, including a pen needle storage compartment or a plurality of pen needle/accessory storage compartments, and which system is capable of being received and carried as an ordinary pen, and which may keep in separation the pen delivery device syringe, the one or more pen needles, and the other related accessories, for instant access as needed, and which forces the user to remove a used pen needle from the pen delivery device syringe prior to re-storage.
[0014] Having an integrated system, which includes the container, the pen delivery device syringe, the pen needle, and related accessories within the same convenient, compact, discreet, and readily accessible unitary tubular structure, is found to solve the aforementioned organizational and storage deficiencies of the prior art. Forcing the separation of the used pen needle from the syringe before allowing re-storage is found to solve the safety concerns associated with the improper re-use of pen needles
[0015] The present invention may be embodied as an easy-to-carry pen-shaped containment system for including, holding, or attaching to a syringe, and having one or more storage compartments which may be used for storing and carrying pen needles or other accessories separately from the pen delivery device syringe.
[0016] The disclosed storage systems are simple in construction and inexpensive to manufacture. The systems may be completely assembled and used with any number of medical or other devices to hold and organize accessories. The disclosed systems are most specifically intended for use in medical insulin delivery, utilizing the storage container as a space to hold required components for the delivery of insulin, but may be adaptable to use in any similar pen delivery device activity. The systems disclosed, according to just an exemplary few of the near infinite number of possible embodiments of the invention, may provide improved accessibility to the pen delivery device syringe and sterile injection pen needles, and improved safety, over prior art storage systems and techniques.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Many aspects of the invention can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present invention.
[0018] FIG. 1A is a perspective view of a pen delivery device syringe of the prior art including stored within its dust cover an attached needle without the needle having the outer cover in place.
[0019] FIG. 1B is a partial exploded view of the pen delivery device syringe, pen needle, and dust cover of FIG. 1A ,
[0020] FIG. 2A is a perspective view of a first exemplary storage system according to the invention having a pen needle storage cap attached to a dust sleeve, which is in turn attached to a pen delivery device syringe,
[0021] FIG. 2B is an exploded view of the storage cap, dust sleeve, pen needle, and syringe of FIG. 2A ,
[0022] FIG. 2C is a cross-sectional view through the storage cap and dust sleeve of FIG. 2A , showing the pen needle stored therein,
[0023] FIG. 2D is an exploded cross-sectional view through the storage cap and dust sleeve of FIG. 2C ,
[0024] FIG. 3A is a perspective view of a second exemplary embodiment of the invention including the a storage cap hinged formed with a dust sleeve, which is in turn attached to a pen delivery device syringe,
[0025] FIG. 3B is an exploded view of the storage cap, dust sleeve, and pen delivery device syringe of FIG. 3A ,
[0026] FIG. 3C is a perspective view of the embodiment of FIG. 3A with the storage cap hinged open to allow access to the pen needle stored within,
[0027] FIG. 4A is a perspective view of a third exemplary embodiment of the invention including the a storage cap attached to a series of intermediary pen needle or accessory storage compartments, which are attached either to an end cap,
[0028] FIG. 4B is an exploded view of the embodiment of FIG. 4A ,
[0029] FIG. 5A is a partial exploded view of a fourth embodiment of the invention including an o-ring for air-tight sealing at the storage cap connection,
[0030] FIG. 5B is a partial exploded view of the embodiment of FIG. 5A showing the storage cap removed and the o-ring attached,
[0031] FIG. 6 is a perspective view of a fifth embodiment of the invention having a transparent needle storage cap,
[0032] FIG. 7 is a perspective view of a sixth embodiment of the invention having a transparent storage cap and a transparent dust sleeve,
[0033] FIG. 8A is an exploded view of an seventh embodiment of the invention having a pen needle ejecting hole in the needle storage cap,
[0034] FIG. 8B is a partially exploded view of the embodiment of FIG. 8A ,
[0035] FIG. 8C is a perspective view of the embodiment of FIG. 8A ,
[0036] FIG. 8D is an illustration showing the ejection of a pen needle assembly from the storage cap of embodiment of FIG. 8A ,
[0037] FIG. 9A is a perspective view of an embodiment of the invention having a pen needle ejection hole in the cap and having the cap hinged formed with the dust sleeve,
[0038] FIG. 9B is a perspective view of the embodiment of FIG. 9A showing the cap in its open position about the hinge,
[0039] FIG. 9C is an exploded view of the embodiment of FIG. 9A ,
[0040] FIG. 9D is a partial cross-sectional view through the embodiment of FIG. 9A ,
[0041] FIG. 10A is a perspective view of an ornamentally styled embodiment of the invention,
[0042] FIG. 10B is an exploded view of the embodiment of FIG. 10A , and
[0043] FIG. 11 is a perspective view of an empty pen needle storage cap according to an additional embodiment being temporarily affixed to the tail end of a pen delivery device syringe for keeping during use of the syringe.
DETAILED DESCRIPTION OF THE INVENTION
[0044] Reference will be made to the appended FIGS. 2A through 11 , where there are shown numerous exemplary embodiments of storage systems for use with insulin delivering pen syringes, in accordance with the invention. In the drawings, like reference numerals designate corresponding parts throughout the views.
[0045] Referring to FIGS. 2A through 2D , system 100 has an open-ended cap 102 with an outer shell 104 having a blunt bullet-shaped first end 106 and a circular second end 108 opposite the first end. A cavity 110 is defined within the shell 104 and has detents 112 for snap-fitted and removable attachment of cap 102 to dust sleeve 126 at peripheral groove 148 . Dust sleeve 126 includes hollow cavity 116 , which includes similar detents 124 for snap-fitted and removable attachment to a typical insulin pen delivery device syringe 120 at peripheral groove 144 .
[0046] Pen delivery device syringe 120 typically includes one or more doses of insulin. Cap 102 and sleeve 126 may alternatively be attached by another suitable attachment means, such as threading.
[0047] Cavity 110 is adapted to receive a typical pen needle assembly 140 including a needle such as needle 141 of FIGS. 1A and 1B . To access the needle assembly, cap 102 must first be removed from sleeve 126 , then needle assembly 140 is removed from cavity 110 . Needle assembly 140 typically includes a protective foil seal 142 , and outer and inner caps which must be removed for access to the needle within. Dust sleeve 126 is removed from pen delivery device syringe 120 so that the pen needle may next be affixed to the pen delivery device syringe's distal end 118 and a dose of insulin may then be administered by hypodermic injection.
[0048] After injection, the needle is removed from the syringe and returned to within the protective case of assembly 140 and appropriated discarded. Failure to remove the pen needle from the pen delivery device syringe denies replacement of dust sleeve, 126 , because the sleeve's distal end 150 would interfere with the pen needle and damage the hypodermic needle making reuse impossible were it not removed. This forces the user to remove the needle. With the needle properly removed using the outer pen needle cap, dust sleeve 126 and cap 102 may be reattached and the assemble may be returned to storage in its original compact and convenient state.
[0049] While not shown, it is noted that the detents 124 are conveniently adapted to receive the distal end 150 and peripheral groove 148 of another identical dust sleeve, which then receives pen delivery device syringe 120 . Such an arrangement allows the system of FIGS. 2A to 2D to be adapted to accommodate any reasonable number of additional dust sleeves in series connection, which can thus be used to store extra needles and other accessories.
[0050] In a second exemplary embodiment, shown in FIGS. 3A through 3C , storage system 200 is shown, having a pen needle storage cap 202 that includes collar 254 , which removably snap-fits to dust sleeve 126 , and which in turn removably snap fits to the pen delivery device syringe 120 . Collar 254 is integrally formed with shell 204 through flexible living hinge member 256 , thereby preventing loss of shell 204 when it is hinged opened as shown in FIGS. 3B and 3C for similar access to the needle assembly (not shown). Otherwise, use and operation of this embodiment is the same as the first embodiment. Hinge member 256 is preferably co-molded with collar 254 and cap 202 of a flexible polymer material such as polypropylene or the like, to allow for repeated flexures of the hinge without breakage.
[0051] Referring now to FIGS. 4A and 4B , there is shown a storage system 300 in which needle-storing cap 124 may be used in conjunction with a selectable plurality of needle-storing or accessory-storing modules 134 . Each module adapted similarly to the cap for receiving and storing either a needle assembly 140 in the same manner as the caps of the previous embodiments, or some other accessories such as blood monitoring strips (not shown), with the last module being snap-fitted to a terminal end plug 320 . The connections of the modules together and to the terminal end cap may also be made by other means, such as threading. And rather than the terminal end cap shown, the last module may alternatively be a dust sleeve such as sleeve 126 in FIG. 2A , which may then receive a pen delivery device syringe. Such a system allows the user to carry numerous pen needles and accessories according to his expected needs, all in one convenient pen-shaped package that can be conveniently stored and transported as an ordinary pen.
[0052] FIGS. 5A and 5B depict a storage system 400 which is an alternate embodiment of the foregoing systems only in that a gasket, such as but not limited to o-ring 436 is used to provide an air-tight seal between cap 124 and dust sleeve 126 . O-ring 436 is fitted over the sleeve's distal end 150 and into peripheral groove 448 , to provide a seal against the cap's circular open end 108 when the cap is fitted to the sleeve.
[0053] FIG. 6 shows a storage system 500 , which could be identical to any of the other embodiments except that cap 524 may be molded of a transparent or tinted material so that the needle assembly 140 can be viewed without disassembly.
[0054] FIG. 7 shows a storage system 600 , which could be identical to any of the other embodiments except that cap 624 , and dust sleeve 626 may be molded of a clear or tinted material so that the contents can be viewed without disassembly.
[0055] FIGS. 8A to 8D show a storage system 700 in which cap 724 has an opening 780 through its upper end 706 through which the tip 742 of needle assembly 140 protrudes, so that it may be easily ejected from the cap. The dust sleeve may be constructed as in the previous embodiments or may be constructed as shown in FIG. 8A , in which separate plug 754 is provided to fit into upper end 750 of sleeve 726 to close off the sleeve and prevent attachment of the sleeve to the syringe unless the needle has been removed. Plug 754 includes peripheral groove 748 to receive the detents (not shown) of cap 724 .
[0056] As best seen in FIG. 8D , once cap 724 is removed, pen needle assembly 140 can be ejected by simply pushing on its tip 742 .
[0057] FIGS. 9A to 9D depict a storage system which combines the ejection hole 780 of the embodiment of FIGS. 8A to 8D with the hinge 256 of FIGS. 3A to 3C .
[0058] FIGS. 10A and 10B depict a storage system 800 similar to that of FIGS. 8A to 8D but having an alternative ornamental design.
[0059] FIG. 11 depicts an alternate embodiment in which cap 902 includes three integral snap detents 912 on circular end 908 of the cap's shell 904 , which are adapted to flex outwardly and snap over the tail end 999 of pen delivery device syringe 120 and into peripheral groove 944 , for convenient keeping while using the pen delivery device syringe. Cavity 910 receives the pen delivery device syringe's tail end 999 during this configuration, or receives the typical needle assembly during storage. As in the previous embodiments, cap 902 may be affixed to the dust sleeve (not shown) at the other end of the pen delivery device syringe, and snap detents 912 then may grasp the dust sleeve at it's peripheral groove during storage.
[0060] Other objects, features and advantages of the invention will become apparent to those skilled in the art from the above description and the accompanying drawings. It should be understood, however, that these specific examples, while teaching exemplary embodiments of the invention, are given only to illustrate and not to limit the scope of the invention. Many changes and modifications may be made while remaining within the invention's scope, which should only be limited by the appended claims.
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A storage system for a needleless pen delivery device syringe and a hypodermic needle adapted for attachment to and use with the pen delivery device syringe. A tubular sleeve has a first hollow chamber for receiving therein the needleless pen delivery device syringe, and a hollow cap has a second hollow chamber for receiving therein the hypodermic needle. The cap is adapted to affix to the sleeve to form a continuous tubular housing, and the sleeve is adapted to receive the pen delivery device syringe only when the needle is not attached to the syringe. Alternative exemplary embodiments provide means for storing other related accessories or additional spare needles.
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BACKGROUND OF THE INVENTION
This invention relates to a focussing lens servo driving device in an optical-type information reading device and, more particularly, to an irradiation light focussing lens servo driving device for use in such an optical-type information reading device.
In an optical-type video disk, so-called "pits" are concentrically or spirally formed in the surface of a recording disk. Video information is recorded by varying the length and interval of these pits. A reflecting film, produced by vacuum-evaporating aluminum or the like, is formed on the surface of the disk where the pits are formed to increase the light reflection factor.
In reading the information recorded on the disk, light is emitted onto the disk from above the surface of the disk where no pits are provided and the light reflected from the reflection film, which is modulated by the presence and absence of the pits, is subsequently demodulated.
A recording disk reading device of this type is provided with a lens focussing servo device which automatically adjusts the lens so that the incident light is focussed on the information recording surface of the disk at all times.
FIG. 1 illustrates schematically one example of a servo focussing device. In the device, light emitted from a light source such as a helium neon laser or the like passes through a collimator lens 2, a beam splitter 3 and a movable mirror 4 and is focussed near an information recording surface 7 by means of a focussing lens 5. A disk 6 is rotated at high speed by an electric motor 14. The reflected light is advanced back along the light path and it is split by the beam splitter 3 and is then converted into an electrical signal by a photo-electric conversion element.
It is impossible to make the disk 6 completely flat and, in general, the disk 6 is inclined when installed on the shaft of the motor 14. Accordingly, the recording surface 7 moves up and down as the disk 6 is rotated. Thus, in order to correctly read the information, it is necessary to move the focussing lens 5 up and down following the up and down movement of the recording surface 7 to thereby maintain the focus of the light beam very near the recording surface 7. For this purpose, a cylindrical lens 8 is disposed before the point where the reflected light from the disk is focussed by the lens 5, that is between the lens 5 and the conjugate point of the disk with respect to the lens 5 and a light receiving element 9 is arranged behind the cylindrical lens 8. The light receiving element 9 is divided into four light receiving element surfaces a, b, c and d as shown in FIG. 2. The light receiving element 9 is so arranged that the division lines of the light receiving element 9 form 45 degree angles with the central axis of the cylinder of the cylindrical lens 8. The light beam passing through the lens 8 is focussed on the two focal lines which are in the plane including the generatrix of the cylindrical lens 8 and in the plane perpendicular to the firstly-mentioned plane, respectively. By utilizing this nature, the configuration of the light beam projected onto the four light receiving element surfaces a, b, c and d are detected to determine the relation between the recording surface 7 and the focal position of the focussing lens 5.
That is, the light receiving surface of the light receiving element 9 is arranged at the position where the reflected light passing through the cylindrical lens 8 becomes substantially circular when the focussing point of the incident light is positioned precisely on the recording surface of the disk by the lens 5, as shown in FIG. 3B. Under this condition, the outputs Va, Vb, Vc and Vd of the light receiving units a, b, c and d are equal to one another.
Va+Vb=Vc+Vd
Accordingly, the output voltage V of a differential amplifier 10 receiving the outputs (Va+Vb) and (Vc+Vd) is zero. As a result, the outputs of an amplifier 11 and a lens drive device 12 are zero and therefore the position of the lens 5 is maintained unchanged.
In the case in which, as shown in FIG. 4A, the incident light is focussed behind the recording surface 7, that is, the distance between the recording surface 7 and the focussing lens 5 is shortened, the configuration of the light beam on the light receiving surface of the light receiving element 9 is as shown in FIG. 4B.
Va+Vb>Vc+Vd
Therefore, the output voltage V(A) of the differential amplifier 10 is positive (V(A)>0).
In the case in which the incident light is focussed before the recording surface 7 as shown in FIG. 5A, the configuration of the light beam is as shown in FIG. 5B
Va+Vb<Vc+Vd
Therefore, the output V(A) of the differential amplifier 10 is negative (V(A)<0).
Thus, if the distance between the lens and the recording surface of the disk is represented by D and the distance when the incident light is focussed correctly on the recording surface is represented by Dj, then the output V(A) of the differential amplifier 10 has an S-shaped waveform characteristic when plotted against D as illustrated in FIG. 6. Therefore, if the output V(A) is amplified as an error signal by the amplifier 11, and is then converted into a displacement value by the drive device 12 and used to control the position of the focussing lens 5 with the aid of the holder 13 automatic focus control is realized.
In general, before the information reading operation is started, the focusing lens 5 is positioned at its fartherst distance away from the recording surface of the disk. If, under this condition, the servo-operation is commenced with the servo loop of the servo focussing circuit closed, an error signal deviated from the linear part of the S-shaped characteristic curve shown in FIG. 6 is produced because the distance D between the lens and the recording surface is long. Therefore, in this case, it is difficult for the servo circuit to carry out an accurate control operation. Even if the servo circuit could operate, the focussing lens is driven out of the control operation range and the operation of the servo circuit is unstable, unless the speed of movement of the focussing lens, that is the value of dD/dt with respect to the disk, is low.
SUMMARY OF THE INVENTION
Accordingly, an object of the invention is to provide a servo driving device for stably operating a servo focussing device as described above.
According to the invention, a focussing lens servo-driving device for an optical-type information reading device includes a focussing lens freely movable between a first position and a second position in a direction perpendicular to the information recording surface of a recording medium, and servo focussing means for controlling the movement of the focussing lens to focus radiated light on the information recording surface. The servo-driving device includes means for driving the focussing lens in a direction from the first position toward the second position, position detecting means for detecting, while the focussing lens is being moved in the driving direction, the movement of the focussing lens over a predetermined distance slightly closer to the second position than a lens position corresponding to the distance Dj between the lens and the recording surface when the light is focussed on the information recording surface so as to produce a predetermined control signal for the period of time during which the lens is moved over the predetermined position, opposite force generating means for applying an opposition force which is gradually decreased to the focussing lens during the period of time of generating of the predetermined control signal in a direction opposite to the driving direction, and means for providing an instruction signal for closing the servo loop of the servo focussing means at the end of generation of the predetermined control signal.
BRIEF DESCRIPTIION OF THE DRAWINGS
FIG. 1 is a block diagram showing the servo unit of a servo focussing lens.
FIG. 2 is a circuit diagram showing an error signal generating structure.
FIGS. 3 through 5 are diagrams used for describing the operation of the servo unit shown in FIG. 1.
FIG. 6 is a diagram indicating the relation between the distance D between the lens and the recording surface and the error signal V(A).
FIG. 7 is a circuit diagram showing a part of one embodiment of the invention.
FIGS. 8A-8E are a series of waveform diagram showing operating waveforms at various parts of the circuit shown in FIG. 7.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The features and advantages of the invention will become more apparent from the following detailed description.
FIG. 7 is a circuit diagram of one embodiment of the invention showing a part of a lens focussing position detecting circuit, a part of an opposition force generating circuit, and an instruction signal generating circuit for closing a servo loop. The error signal V(A) of the differential amplifier 10 in FIG. 1 or 2 is applied to one input terminal of a comparator 20 while to the other input terminal a reference signal (voltage) V R is applied through resistors R1 and R2. When the error signal V(A) is greater than the reference signal V R , then a high level control signal B is provided as the output of the comparator 20.
The control signal B is applied to a differentiation circuit including a capacitor C1 and a resistor R3 where it is converted into a differentiation waveform signal C. The time constant C1·R3 of the differentiation circuit is so selected that, during the presence of the signal B, the amplitude of signal B is gradually decreased. The output C is employed as an opposition signal generating signal. A diode D1 blocks a negative differentiation waveform signal.
The control signal B is further applied to a differentiation circuit including a capacitor C2 and a resistor R4 where it is converted into a negative trigger pulse D which triggers a flip-flop FF in the following stage. A diode D2 blocks a positive differentiation pulse. The output of the flip-flop FF is applied through a resistor R6 to the base of a drive transistor Q1 which is also connected through a resistor R5 to a voltage +Vcc. A voltage -Vcc is applied to the collector of the transistor Q1 through a resistor R7. The collector output E of the transistor Q1 is employed as a servo driving instruction signal. A diode D3 serves to maintain the other input of the comparator 20 at the high level +Vcc so that after the servo loop is closed by generation of the instruction signal E the opposition force generating pulse C is not produced by the control signal output B of the comparator.
Waveforms at various parts of the circuit in FIG. 7 are as shown in FIGS. 8A-8E. In FIGS. 7 and 8A-8E, like wave forms are designated by like reference characters. The operation of the circuit in FIG. 7 will further be described with reference to FIGS. 1 and 8A-8E.
It is assumed that the focussing lens 5 is at its maximum distance from the recording surface 7 of the disk 6 and that the servo focussing operation is started under these conditions. In this case, in the servo unit shown in FIG. 1, the amplifier 11 is disconnected from the lens drive device 12, for instance, to open the servo loop and the output of a drive signal generator (not shown) separately provided is employed as the drive input of the lens drive device 12. By this output, the lens 5 is moved toward the recording surface. At this time, the high level signal is applied to the set input F of the flip-flop FF to set the latter FF. The error signal (see FIG. 6), that is the output V(A) of the amplifier 10 as in FIG. 2 is applied to the one input of the comparator 20.
The voltage corresponding to an error signal obtained when the lens 5 is at a predetermined position is employed as the reference signal V R which is applied to the other input of the comparator 20. The predetermined position is somewhat closer to the recording surface than the lens position corresponding to a distance Dj, the distance between the lens and the recording surface when the light beam is focussed on the recording surface. When the lens is at the predetermined position, the distance between the lens and the recording surface is represented by D R .
Accordingly, when the distance D between the lens and the recording surface is changed through Dj to D R , the output B of the comparator 20 is raised to the high level (FIG. 8B) and is differentiated by the differentiation circuit of the capacitor C1 and the resistor R3 as a result of which the opposition force generating signal as shown in FIG. 8C is produced. An opposition force proportional to the amplitude of the opposition force generating signal is exerted on the lens. As a result, the speed of movement of the lens is abruptly decreased. When the speed of movement of the lens becomes zero, the lens is pulled in the opposite direction, that is, in the direction of the opposition force until it reaches the point D R . At the same time, the output B of the comparator 20 is set to the low level and the opposition force generating signal is removed so that no opposition force is exerted on the lens. Thus, the trigger pulse D is produced by the differentiation circuit made up of the capacitor C2 and the resistor R4 which in turn sets the output of the flip-flop FF to the low level as a result of which the drive transistor Q1 is rendered conductive (on). Therefore, the collector output E of the transistor Q1 is changed from the low level to the high level. The amplifier 11 can then be connected to the lens drive device 12 to close the servo loop of FIG. 1.
At this time instant, the movement direction of the lens 5 becomes opposite to that during the initial period and an absolute value (magnitude) of the velocity is much smaller than that during the initial period. Thus, an optimum servo driving condition is produced and the servo operation is stably carried out.
If the output B of the comparator 20 were to be used directly as the opposition force generating signal, the speed of the lens 5 which result when it is returned to the point D R is opposite in direction to that at the initial period. Since its amplitude is constant, however, the magnitude of the speed would not have changed and it would remain high. Therefore, stable servo driving would not be carried out.
As is apparent from the above description, according to the invention, when the lens approaches near the position corresponding to the distance Dj between the lens and the recording surface when the light beam is correctly focussed on the recording surface, the servo loop is closed and the lens speed dD/dt is maintained sufficiently small for the servo unit to be stably driven.
The invention has been described with reference to the case where the operation is started under the condition that the lens is relatively far from the recording surface. However, it should be noted that the technical concept of the invention can be applied to the case also where the operation is commenced under the condition that the lens is at its closest position to the recording surface.
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A focussing lens servo driving device for an optical information reading device in which the lens is first driven towards the focussed position with a controlling servo circuit operated in an open loop mode. Once the lens has passed a predetermined position an opposition force is produced in dependance on the lens position. The opposition force is gradually reduced and the servo loop is closed when the lens has been turned back to the predetermined position so that stable operation is provided.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of Invention
[0002] The present invention relates generally to preservative systems and their use in compositions. More particularly, the present invention relates to synergistic preservative systems and their use in cosmetic compositions.
[0003] 2. Description of Related Art
[0004] Preservatives are frequently used in all types of cosmetic compositions to prevent decay and breakdown of such compositions mainly caused by microorganisms. Effective preservatives must have two types of activity, namely anti-microbial activity and anti-fungal activity. Most of the current preservatives contain some form of paraben, often in combination with phenols and quaternary compounds. Some of these paraben preservative systems, however, are limited in their global acceptability and are not allowed in either Europe or Japan.
[0005] Various parabens have shown estrogenic activity and other deleterious effects on reproductive systems in various test models. See Pedersen, K. L. et al., The preservatives ethyl -, propyl - and butylparaben are estrogenic in an in vivo fish assay , Pharmacology & Toxicology (Vol. 86(3), pp 110-13, March 2000); Routledge, E. J., et al., Some alkyl hydroxy benzoate preservatives ( parabens ) are estrogenic , Toxicology and Applied Pharmacology (Vol. 153(1), pp. 12-19 (Nov. 1998); and Kang, K. S. et al, Decreased sperm number and motile activity on the F 1 offspring maternally exposed to butyl p - hydroxybenzoic acid ( butyl paraben ), Journal of Veterinary Medical Science (Vol. 64(3), pp. 227-35 (March 2002); and Philippa Darbre and Philip Harvey, Endocrine disrupters and human health: could estrogenic chemicals in body care cosmetics adversely affect breast cancer incidence in women ?, Journal of Applied Toxicology, 2004—June; 24 (3): 167-76.
[0006] Likewise, while effective, other preservative systems, such as, formaldehyde donors, isothiazolinones, and ethanols are defective in numerous safety/compatibility-related issues, for example, high irritation potential and incompatibility with avobenzone. Therefore, glycol, by itself, cannot substitute the anti-bacterial and anti-fungal properties of a preservative in a typical cosmetic composition.
[0007] It is also known that certain glycols offer some anti-bacterial efficacy at relatively high concentrations of glycol, in the range between 1% to 7%, based on a total weight of a composition. In addition, it was also found that glycols have limited or non anti-fungal efficacy,
[0008] Accordingly, while there have been attempts in the prior art to formulate paraben-free compositions, there is still a strong need in the art for a preservative composition or system that is not only paraben-free, but also has less irritation potential, has both antimicrobial and fungicidal activity, and has lower manufacturing costs. The present invention meets these needs.
SUMMARY OF THE INVENTION
[0009] It is an object of the present invention to provide a preservative system suitable for use in cosmetic compositions.
[0010] It is another object of the present invention to provide such a preservative system that includes at least one preservative component and at least one oil-miscible glycol component.
[0011] It is still another object of the present invention to provide such a preservative system that exhibits synergistic properties.
[0012] It is a further object of the present invention to provide such a preservative system that provides both antimicrobial and fungicidal activities.
[0013] It is still a further object of the present invention to provide such a preservative system that reduces the required amounts of preservative component while maintaining adequate preservative efficacy in a cosmetic composition, which leads to cost reductions and lower irritation potential.
[0014] It is yet a further object of the present invention to provide such a preservative system with increased antioxidant and moisturizing potential.
[0015] It is another object of the present invention to provide improved ease of formulation of a cosmetic composition with respect to color, pH, and viscosity.
[0016] These and other objects of the present invention are achieved by providing a preservative system having at least one preservative component and at least one oil-miscible glycol component, and cosmetic compositions formulated with the preservative system. It has unexpectedly been found that the preservative system according to the present invention results in a synergistic preservative effect. This synergistic preservative effect allows for the use of a reduced amount of the preservative component when formulating a cosmetic composition, which in turn results in a composition with reduced irritation potential and reduced material costs.
DETAILED DESCRIPTION OF THE INVENTION
[0017] The present invention provides enhanced or synergistic preservative systems for use in topical compositions, such as cosmetic and dermatological compositions. In particular, it has been found that a preservative system with one or more oil-miscible glycols and one or more preservative components results in a synergistic preservative system that is effective for use in topical compositions. These synergistic preservative systems demonstrate adequate anti-microbial efficacy without the use of harsher preservative systems, such as, formaldehyde donors, parabens, ethanols, and isothiazolinones. In one embodiment of the present invention, the preservative system is free of formaldehyde donors, parabens, ethanols, and isothiazolinones. These systems may support preservative-free product claims and may also provide anti-oxidant and moisturization benefits.
[0018] While some glycols have anti-bacterial efficacy, their efficacy is proficient only at relatively high concentrations. When one or more oil-miscible glycols are combined with one or more preservative components according to the present invention, however, the combination unexpectedly results in a synergistic preservative system that is free of harsh preservatives, but is still anti-fungal and/or anti-bacterial. Furthermore, as a result of the synergism between the one or more oil-miscible glycols and the one or more preservative components, reduced concentrations of each are required in a cosmetic composition to achieve anti-fungal and/or anti-bacterial activity in the present invention.
[0019] Additionally, the use of the one or more oil-miscible glycols in the present invention provides broader formulation opportunities. This includes, but is not limited to, allowing for formulating systems and/or compositions with low water content.
[0020] Suitable oil-miscible glycols for use in the present invention include, but are not limited to, one or more of pentylene glycol, neopentyl glycol, caprylyl glycol, benzyl glycol, hexanediol, ethyl hexanediol, or any combinations thereof. In one embodiment according to the present invention, the glycol is caprylyl glycol, which is, by way of example, commercially available from Inolex Chemical Company under the trade name LexGard® O. In another embodiment, the glycol is a neopentyl glycol, which is, by way of example, commercially available from Inolex Chemical Company under the tradename LexFeel® 7.
[0021] The one or more oil-miscible glycols are present in the preservative system in an amount about 50 wt. % to about 90 wt. % based on the total weight of the preservative system. In one embodiment, the one or more oil-miscible glycols are present in an amount about 65 wt. % to about 85 wt. %, based on the total weight of the preservative system. In yet another embodiment, the one or more oil-miscible glycols are present in an amount about 75 wt. % to about 85 wt. %, based on the total weight of the preservative system.
[0022] The one or more oil-miscible glycols are present in a cosmetic composition in an amount about 0.1 wt. % to about 5 wt. %, based on the total weight of the cosmetic composition. In one embodiment of the present invention, the one or more oil-miscible glycols are present in an amount about 0.5 wt. % to about 4 wt. %, based on the total weight of the cosmetic composition. In another embodiment of the present invention, the one or more oil-miscible glycols are present in an amount about 0.75 wt. % to about 3.25 wt. %, based on the total weight of the cosmetic composition.
[0023] Suitable preservative components for the use in the preservative system according to the present invention include, but are not limited to, at least one organic acid, organic acid derivative, inorganic acid, inorganic acid derivative, or any combinations thereof.
[0024] Suitable organic acid or organic acid derivative preservative component for use in the preservative system of the present invention include, but are not limited to, erythrobic acid, benzoic acid, citric acid, sorbic acid, glucono-1,5-lactone (GDL), which is a neutral cyclic ester or gluconic acid, sodium erythorbate, sodium benzoate, sodium citrate, sodium sorbate, potassium sorbate, sodium gluconate, EDTA, disodium EDTA, trisodium EDTA, tetrasodium EDTA, or any combinations thereof.
[0025] Suitable inorganic acid or derivatives for the preservative components for use in the present invention include, but are not limited to, sodium sulfite, sodium metabisulfite, or any combinations thereof.
[0026] In one embodiment of the present invention, the preservative component of the preservative system includes a combination of organic acid or derivative and inorganic acid or derivative. In this embodiment, the components are present in a ratio of organic acid or derivative to inorganic acid or derivative between about 1:1 to about 4:1.
[0027] In one embodiment of the present invention, the preservative system includes one or more of GDL, sodium erythorbate, sodium benzoate, disodium EDTA, or any combinations thereof.
[0028] The one or more preservative components are present in the preservative system in an amount about 10 wt. % to about 50 wt. %, based on the total weight of the preservative system. In one embodiment, the one or more preservative components are present in an amount about 15 wt. % to about 35 wt. %, based on the total weight of the preservative system. In another embodiment of the present invention, the one or more preservative components are present in an amount about 15 wt. % to about 25 wt. %, based on the total weight of the preservative system.
[0029] The one or more preservative components are present in a final cosmetic composition in an amount about 0.05 wt. % to about 5 wt. %, based on the total weight of the cosmetic composition. In one embodiment, the one or more preservative components are present in an amount about 0.075 wt. % to about 2.5 wt. %, based on the total weight of the cosmetic composition. In another embodiment of the present invention, the one or more preservative components are present in an about 0.1 wt. % to about 0.75 wt. %, based on the total weight of the cosmetic composition.
[0030] By way of example, in another embodiment of the present invention, suitable preservative components for use in the present invention include the Natrulon GPS family of components sold commercially by Lonza. The Cosmetic, Toiletry, and Fragrance Association (CTFA) list selected components of NATRULON GPS as antioxidants/moisturizers. Natrulon GPS # 4 includes 75% glucono-delta-lactone (GDL) and 25% sodium erythorbate. Natrulon GPS # 5 includes 75% GDL and 25% sodium benzoate. Natrulon GPS # 6 includes 60% GDL, 20% sodium erythorbate and 20% sodium sulfite. Also, oil-miscible glycols are known to have humectant properties. Therefore, in addition to providing enhanced anti-microbial and fungicidal properties to cosmetic compositions, the synergistic preservative system of the present invention may also impart desirable antioxidant and moisturizing properties to these compositions.
[0031] In one embodiment of the present invention, the preservative system used in a cosmetic composition includes one or more oil-miscible glycols and one or more of the Natrulon GPS components. The one or more oil-miscible glycols are present in an amount about 0.5 wt. % to about 3.5 wt. %, based on the total weight of the cosmetic composition. The one or more Natrulon GPS components are present in an amount about 0.45 wt. % to about 0.65 wt. %, based on the total weight of the cosmetic composition. These embodiments of the present invention yield surprisingly positive results despite the reduction in the amount of both the glycol and preservative components compared to the amounts typically used and/or recommended for use in cosmetic compositions. It was found that when used in a cosmetic composition, such combinations, in such amounts, provide both anti-microbial and anti-fungicidal activities.
[0032] The cosmetic composition formulated with the synergistic preservative system according to the present invention may also include one or more additional components or ingredients including, but not limited to, solvents, surfactants, emulsifiers, emollients, humectants, moisturizers, thickeners, antioxidants, vitamins, sunscreen agents, additional preservatives, pH adjusters, chelating agents, viscosity modifiers, or any combinations thereof.
[0033] The present invention also relates to a cosmetic composition formulated with the synergistic preservative system of the present invention. The cosmetic composition may be any known cosmetic composition, such as, for example, sunscreen, personal care, skin care, hair care, color cosmetic, anti-aging, or any combinations thereof. The cosmetic compositions may be in any suitable form, including, but not limited to, lotion, cream, spray, gel, foam, powder, stick, or any combinations thereof.
[0034] The synergistic preservative system of the present invention may be included in a cosmetic composition in an amount about 0.15 wt. % to about 10 wt. %, based on the total weight of the cosmetic composition. In one embodiment of the present invention, the synergistic preservative system is present in a cosmetic composition in an amount about 0.575 wt. % to about 6.5 wt. %, based on the total weight of the cosmetic composition. In another embodiment of the present invention, the synergistic preservative system is present in a cosmetic composition in an amount about 0.85 wt. % to about 4 wt. %, based on the total weight of the cosmetic composition.
[0035] The following example is merely illustrative of a cosmetic composition formulated with a synergistic preservative system according to the present invention. The example is not intended to limit the scope of the invention.
EXAMPLE
[0036] Referring to Table 1 below, Formula A represents a cosmetic composition without a synergistic preservative system according to the present invention. Formulas B and C represent cosmetic compositions formulated with a synergistic preservative system according to the present invention.
TABLE 1 TOTAL WT TOTAL WT TOTAL WT % % % CHEMICAL/INCI/USP NAME TRADE NAME A B C Purified Water 65.10 64.10 64.10 Octyl Salicylate Neo Heliopan OS 5.00 5.00 5.00 Homosalate Escalol 567 7.50 7.50 7.50 Avobenzone Parsol 1789 3.00 3.00 3.00 Octocrylene 2.50 2.50 2.50 Oxybenzone 1.50 1.50 1.50 Cetearyl Alcohol (and) Dicetyl Crodophos CES 5.50 5.50 5.50 Phosphate (and) Ceteth-10 Phosphate Polyacrylamidomethylpropane Cosmedia Polymer 4.50 5.00 5.00 Sulfonic Acid HSP 1180 Caprylyl Glycol LexGard O 3.50 2.00 2.00 Sodium Hydroxide, 10% soln 1.80 3.10 3.10 Disodium EDTA Dissolvine Na2 0.10 0.10 0.10 Xanthan Gum 0.00 0.20 0.20 Glucono Delta Lactone (GDL) Natrulon GPS # 4 0.50 (and) Sodium Erythrobate* Glucono Delta Lactone (GDL) Natrulon GPS# 5 0.50 (and) Sodium Benzoate** 100.00 100.00 100.00 *75% Glucono Delta Lactone (GDL) (and) 25% Sodium Erythrobate **75% Glucono Delta Lactone (GDL) (and) 25% Sodium Benzoate
[0037] In the Table 2 below, Formulas D and E represent additional examples of a cosmetic compositions formulated with a synergistic preservative systems according to the present invention.
TABLE 2 TOTAL WT TOTAL WT % % CHEMICAL/INCI/USP NAME TRADE NAME D E Purified Water, USP Purified Water, USP 61.556 61.556 Mineral Oil and Lanolin Alcohol Amerchol L-101 1.440 1.440 Lanolin, Anhydrous Cosmetic Lanolin (Rita) 0.144 0.144 Glyceryl Stearate Witconol MST 2.100 2.100 Glyceryl Stearate and PEG-100 Arlacel 165 2.750 2.750 Stearate Cetyl Alcohol Adol 52 NF 1.600 1.600 Octinoxate 7.000 7.000 Octocrylene 1.250 1.250 Octisalate 5.000 5.000 Avobenzone Parsol 1789 1.500 1.500 Neopentyl Glycol Diheptanoate LexFeel 7 2.500 2.500 Caprylyl Glycol LexGard O 0.750 0.750 Tocopherol Tocopherol USP-FCC 0.010 0.010 Retinyl Palmitate Retinyl Palmitate Type 0.010 0.010 P1.7E Cholecalciferol Liquid Vitamin D3 in corn 0.010 0.010 oil Dimethicone Silicone Fluid 350 cst 1.000 1.000 Xanthan Gum Vanzan NF 0.350 0.350 Disodium EDTA Dissolvine Na2× 0.100 0.100 Glycerin, USP Glycon G-100 6.000 6.000 Sodium Hydroxide 10% solution 3.520 3.520 qs to pH ˜6.0 Allantoin 0.500 0.500 Aloe Vera Gel Aloe-Con UP-40 0.010 0.010 Glucono Delta Lactone (GDL) Natrulon GPS # 4 0.600 (and) Sodium Erythrobate* Glucono Delta Lactone (GDL) Natrulon GPS# 5 0.600 (and) Sodium Benzoate** Fragrance 0.300 0.300 Total 100.000 100.000 *75% Glucono Delta Lactone (GDL) (and) 25% Sodium Erythrobate **75% Glucono Delta Lactone (GDL) (and) 25% Sodium Benzoate
[0038] Formulas A through E were tested with the following bacteria and fungi for in vitro effectiveness:
[0039] Gram negative bacilli for bacterial pool:
A. Pseudomonas aeruginosa ATCC 9027 B. Burkholderia cepacia ATCC 25416
[0040] Gram positive cocci for bacterial pool:
A. Staphylococcus aureus ATCC 6538
[0041] Enteric organisms for bacterial pool:
A. Eschericia coli ATCC 8739 B. Klebsiella pneumoniae ATCC 13883
[0042] Fungi pool:
A. Candida albicans ATCC 10231 B. Penicillium chrysogenum ATCC 10106 C. Aspergillus niger ATCC 16404
[0043] The working cultures of the bacteria and fungi were prepared using the ATCC Culti-Loop (Bio-Mereiux-Remel). Bacterial and fungi cultures were inoculated and incubated to produce the desired inoculum pools that are appropriate for the testing.
[0044] Each inoculum pool was then mixed with a 50 gram sample of test product and was shaken vigorously to create a homogeneous mixture. Each mixture then was stored at ambient temperature and humidity. Water miscible products in the mixture were further treated with a modified Williamson Buffer Solution (WBS) (0.4 g of KH 2 PO 4 , 10.1 g of NA2 HPO 4 , 10.0 mL of Tween 80, 0.09 g of sodium bisulfite in 1 L of DI water) to render homogeneous and dispersed. 1.0 mL of the 1:10 dilution in WBS of each mixture was dispensed into its respective labeled petri dish with 20 mL of Trypticase Soy Broth for each bacterial plate and 20 mL of Sabouraud Dextrose Agar for each fungi plate. The plates were allowed to solidify and were incubated and re-inoculated after 7 days. The dishes were assayed at 7, 14, and 21 days after the re-inoculation for a total test period of 28 days.
[0045] Product is considered to be adequately preserved (passed) if the bacterial count is <10 colony forming units (CFU)/gm at day 7 and day 14, post inoculation, with no increase in growth for the remaining test period. Product is adequately preserved (passed) if the fungal count is <1000 CFU/gm at day 7 and day 14, post inoculation, with no increase in growth for the remaining test period.
[0046] The results presented in Table 3 indicate that that the use of caprylyl glycol alone even at high concentration, 3.5%, failed to provide adequate preservative properties (Formula A). In contrast, caprylyl glycol in combination with glucono-delta-lactone and sodium erythorbate and sodium benzoate provides proficient preservative properties (Formulas B and E with sodium erythorbate; and Formulas C and D with sodium benzoate). Total concentrations of compositions of glucono-delta-lactone and sodium erythorbate and glucono-delta-lactone and sodium benzoate were in the range of from 0.5% to 0.6%—below their effective level. The effective concentrations of caprylyl glycol were in the range of 0.75-2%.
TABLE 3 The results of the determination of in vitro efficacy of antimicrobial agents in Formulations A through E: Day 7: Day 1 Day 3 Reinoculation Day 14 Day 21 Day 28 Result Composition A Bacilli, CFU/gm 0 0 0 0 20 10 Failed Fungi, CFU/gm 200 300 100 300 400 400 Failed Composition B Bacilli, CFU/gm 0 0 0 0 0 0 Passed Fungi, CFU/gm 40 0 0 0 0 0 Passed Composition C Bacilli, CFU/gm 0 0 0 0 0 0 Passed Fungi, CFU/gm 10 0 0 0 0 0 Passed Composition D Bacilli, CFU/gm 0 0 0 0 0 0 Passed Fungi, CFU/gm 20 0 0 0 0 0 Passed Composition E Bacilli, CFU/gm 0 0 0 0 0 0 Passed Fungi, CFU/gm 60 40 0 0 0 0 Passed
[0047] The present invention has been described with particular reference to the preferred forms thereof. It will be obvious to one of ordinary skill in the art that changes and modifications may be made therein without departing from the spirit and scope of the present invention as set forth above and the claims below.
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The present invention provides a preservative system having at least one preservative component and at least one oil-miscible glycol component, and cosmetic compositions formulated with the preservative system. It has unexpectedly been found that the preservative system according to the present invention results in a synergistic preservative effect. This synergistic preservative effect allows for the use of a reduced amount of the preservative component when formulating a cosmetic composition, which in turn results in a composition with reduced irritation potential and reduced material costs.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims benefit under 35 U.S.C. §119 of Taiwanese Patent Application No. 101117920, filed on May 18, 2012, the contents of which are incorporated by reference as if fully set forth herein in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to benzopyran-4-one derivatives compound capable of inhibiting ATR and FANCD2 activation, and more particularly to those benzopyran-4-one derivatives compound capable of improving the cancer sensitivity and poor prognosis to DNA-damaging therapeutics.
BACKGROUND OF THE INVENTION
[0003] The benzopyran-4-one derivatives compound of formula I having a flavonoid moiety, which previously isolated and identified from the whole plant extract of Thelypteris torresiana , a fern species native to Taiwan.
[0004] The exposure and biological effects of Protoapigenone (I-1), 5′,6′-Dihydro-6′-methoxy-protoapigenone (I-2) and Protoapigenin (I-3) compounds have been investigated by cytotoxicity assay. It was found Protoapigenone (I-1) demonstrated therapeutic effects and was a lead compound for potential anticancer drug development.
[0000]
[0005] Furthermore, for developing a new potent anticancer drug, several analogues of I type compound such as I-4, I-5, I-6, I-7 and I-8, and another II type moiety such as II-1 and II-2 compound are also synthesized or semi-synthesized. Where the compound I-4 having chemical name 2-(1-hydroxy-4-oxocyclohexa-2,5-dienyl)-4H-chromen-4-one can be expressed by the general names of protoflavonone. The compound I-5 is also termed as 5-hydroxyprotoflavone, whose chemical name is 2-(1-hydroxy-4-oxocyclohexa-2,5-dienyl)-5-hydroxy-4H-chromen-4-one. The compound I-6 having chemical name 5-hydroxy-2-(1-hydroxy-4-oxocyclohexa-2,5-dienyl)-7-methoxy-4H-chromen-4-one can be expressed by the general names of 5-hydroxy-7-methoxy-protoflavonone. The homologous compounds I-4 and 1-7 have the similar structure, but a different function group on R11 positions only, which is a hydroxyl group and another is methoxyl group in that position. The compound I-5, I-8, II-1 and II-2 also present the modified function group of R11 positions models.
[0000]
[0006] Formula II having an β-naphthoflavone moiety, the compound II-1 has chemical name 3-(1-hydroxy-4-oxo-cyclohexa-2,5-dienyl)-1H-benzo[f]chromen-1-one. The compound II-2 has chemical name 1′-methoxy-β-naphthoflavone.
[0000]
[0007] In previous studies, Protoapigenone (I-1) and its more potent analog compound II-1 ( FIG. 1A ) were shown to induce oxidative stress, consequently activating the p38 and JNK1/2 MAPK pathways following cell cycle arrest and apoptosis in several cancer cell types. These compounds were also found to reduce the size of tumor xenografts in nude mice without exerting toxic effects on the recipient. Recently, in those compounds of formula I and II were found to induce chromosomal breakage through oxidative stress, implicating a role for benzopyran-4-one derivatives of formula I and II in interfering with DNA metabolism. Up to date, the biomolecular actions and implications of this benzopyran-4-one derivatives mediated interference are mostly undetermined. Herein, it is found that benzopyran-4-one derivatives are capable of inhibiting DNA damage-induced activation of ATR targets Chk (Cell Cycle Checkpoint Kinase) 1 and FANCD2, which then sensitize tumor cells to chemotherapy, and finally results in tumor size reduction in mice. The experiment results show that these benzopyran-4-one derivatives compounds are noteworthy potential to treat cancers by inducing replication stress via the inhibition of ATR signaling cascades.
SUMMARY OF THE INVENTION
[0008] In accordance with an aspect of the present invention, compounds of benzopyran-4-one derivatives, characteristically with inhibiting of DNA Damage Response (DDR), are provided. The benzopyran-4-one derivatives includes a common structure being the following formula I:
[0000]
[0009] wherein: R 3 , R 5 , R 7 , R 11 , R 14 and R 16 are selected independently from a group consisting of a hydrogen, a hydroxyl group, a methoxyl group and a oxygen atom contain a double bond.
[0010] In accordance with a further aspect of the present invention, compounds of benzopyran-4-one derivatives, characteristically with ATR-mediated DNA damage checkpoint, is provided. The benzopyran-4-one derivatives includes a common structure being the following formula II;
[0000]
[0011] wherein: R 21 is selected independently from a group consisting of a hydrogen, a hydroxyl group and a methoxyl group.
[0012] In a further aspect of the present invention, a method for assaying a state of DNA DDR kinase signaling cascades is provided. The method includes steps of:
providing a reaction site thereof; adding to the reaction site an effective amount of a benzopyran-4-one derivative represented by one of formula I and formula II,
[0000]
wherein each of R 3 , R 5 , R 7 , R 11 , R 14 , and R 16 is one selected from a group consisting of a hydrogen, a hydroxyl group, a methoxyl group and a oxygen atom containing a double bond. R 21 is one selected from a group consisting of a hydrogen, a hydroxyl group and a methoxyl group.
[0016] The above objects and advantages of the present aspects will become more readily apparent to those ordinarily skilled in the art after reviewing the following detailed descriptions and accompanying drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee
[0018] FIG. 1 illustrates Protoapigenone (I-1) induce chromosome aberration but does not produce marked DDR.
[0019] FIG. 2 illustrates immunoblots showing DDR by detecting phosphorylation of cell marker following exposure of HEK293T cell to 10 μM compound I-1 for the indicated times.
[0020] FIGS. 3( a )- 3 ( b ) show that dose-dependent effects of compound I-1 and compound II-1 on the inhibition of UV-induced Chk1 phosphorylation in cells.
[0021] FIG. 3( a ) illustrates immunoblots showing the expression of MDA-MB-231 cell.
[0022] FIG. 3( b ) illustrates immunoblots showing the expression of A549 cell.
[0023] FIG. 4 shows the cytotoxic effect of compound against cell line.
[0024] FIGS. 5( a )- 5 ( b ) show benzopyran-4-one derivatives inhibit DNA damage-induced DDR.
[0025] FIG. 5( a ) illustrates immunoblots showing the expression of inhibit Chk1 phosphorylation.
[0026] FIG. 5( b ) illustrates immunoblots showing the expression of A549 cell. Cells pretreated with 50 μM okadaic acid (OA) or 20 μM MG132 and subjected to 10 J/m 2 UV for 1 h to induce DDR.
[0027] FIGS. 6( a )- 6 ( b ) show benzopyran-4-one derivatives inhibit UV-induced Chk1 phosphorylation.
[0028] FIG. 6( a ) illustrates immunoblots showing the expression of A549 cell.
[0029] FIG. 6( b ) illustrates immunoblots showing the expression of MDA-MB-231 cell. Cells pretreated with chemicals for 20 min and subjected to 10 J/m 2 UV for 1 h to induce DDR.
[0030] FIG. 7 shows benzopyran-4-one derivatives inhibit chemotherapeutic agents-induced Chk1 phosphorylation.
[0031] FIGS. 8( a )- 8 ( b ) show benzopyran-4-one derivatives inhibit ATR-dependent Chk1 phosphorylation.
[0032] FIG. 8( a ) illustrates immunoblots showing the expression DDR induced by H 2 O 2 (peroxide).
[0033] FIG. 8( b ) illustrates immunoblots showing the expression DDR induced by hydroxyurea (HU).
[0034] FIG. 9 shows the effect of compound II-1 on phosphorylation were assayed after UV irradiation on HEK293T cell, and this exhibited decreased expression of genes following the RNA interference treatment.
[0035] FIGS. 10( a )- 10 ( c ) show benzopyran-4-one derivatives inhibit UV- or H 2 O 2 -induced Chk1 phosphorylation
[0036] FIG. 10( a ) illustrate immunoblots showing compound I-1 inhibit H 2 O 2 -induced Chk1 phosphorylation.
[0037] FIG. 10( b ) illustrate immunoblots showing compound I-1 inhibit UV-induced Chk1 phosphorylation.
[0038] FIG. 10( c ) illustrate immunoblots showing compound II-1 inhibit H 2 O 2 -induced Chk1 phosphorylation.
[0039] FIG. 11 illustrate immunoblots showing compound I-1 inhibit H 2 O 2 -induced Chk1 phosphorylation. Effects of compound I-1 on Chk1 phosphorylation were assayed 1 h after 10 J/m 2 UV irradiation on HEK293T cell overexpressing ATRIP, TopBP1, claspin, or ATR following delivery of tagged full-length cDNA constructs for 48 h.
[0040] FIGS. 12( a )- 12 ( b ) show benzopyran-4-one derivatives inhibit DNA damage checkpoint and repair.
[0041] FIG. 12( a ) illustrates percentages of the mitotic marker.
[0042] FIG. 12( b ) illustrates the expression FACS (Fluorescence Activated Cell Sorting) dot blot for analyzing the percentage of GFP cell denoting the HRR frequency.
[0043] FIG. 13 illustrates the percentage of M-phase cells with γH2AX foucus formation.
[0044] FIGS. 14( a )- 14 ( c ) show the benzopyran-4-one derivatives inhibit cisplatin-induced Chk1 phosphorylation and FANCD2 monoubiquitination.
[0045] FIG. 14( a ) illustrates immunoblots showing the effect on cisplatin-induced DDR in A594 cell.
[0046] FIG. 14( b ) illustrates immunoblots showing the effect on cisplatin-induced DDR in U2OS cell.
[0047] FIG. 14( c ) illustrates immunoblots showing the effect on cisplatin-induced DDR in MDA-MB-231 cell.
[0048] FIGS. 15( a )- 15 ( b ) show that in vitro clonogenic survival for A549 cell.
[0049] FIG. 15( a ) illustrates the effects fraction of compound I-1.
[0050] FIG. 15( b ) illustrates the effects fraction of compound II-1.
[0051] FIGS. 16( a )- 16 ( b ) show that in vitro clonogenic survival for MDA-MB-231 cell.
[0052] FIG. 16( a ) illustrates the effects fraction of compound I-1.
[0053] FIG. 16( b ) illustrates the effects fraction of compound II-1.
[0054] FIGS. 17( a )- 17 ( b ) show chemosensitization effect of benzopyran-4-one derivatives.
[0055] FIG. 17( a ) illustrates the effects fraction of compound I-1.
[0056] FIG. 17( b ) illustrates the effects fraction of compound II-1.
[0057] FIG. 18 shows that in vivo xenograft tumor volume for MDA-MB-231 cell.
A—cisplatin 2 mg/kg B—cisplatin+compound II-1 0.2 mg/kg C—compound II-1 0.2 mg/kg
[0061] FIGS. 19( a )- 19 ( b ) show that optical activity of benzopyran-4-one derivatives.
[0062] FIG. 19( a ) illustrates the effects on A549 cells
A—control B—0.25 μM compound I-1 C—0.5 μM compound I-1 D—1 μM compound I-1
[0067] FIG. 19( b ) illustrates the effects on MDA-MB-231 cells
A—control B—0.25 μM compound I-1 C—0.5 μM compound I-1 D—1 μM compound I-1
[0072] FIGS. 20( a )- 20 ( b ) show that optical activity affected by benzopyran-4-one derivatives concentration.
[0073] FIG. 20( a ) illustrates the effects of compound I-1.
A—control B—0.1 μM compound II-1 C—0.2 μM compound II-1 D—0.4 μM compound II-1
[0078] FIG. 20( b ) illustrates the effects of compound II-1.
A—control B—0.1 μM compound II-1 C—0.2 μM compound II-1 D—0.4 μM compound II-1
[0083] FIGS. 21( a )- 21 ( b ) show that rate of cell cycle progression.
[0084] FIG. 21( a ) illustrates the effects of unsynchronized cells.
[0085] FIG. 21( b ) illustrates the effects of control group.
[0086] FIGS. 22( a )- 22 ( c ) show that rate of cell cycle progression were treated with benzopyran-4-one derivatives for 6 hrs.
[0087] FIG. 22( a ) illustrates the effects of control group.
[0088] FIG. 22( b ) illustrates the effects of compound I-1.
[0089] FIG. 22( c ) illustrates the effects of compound II-1.
[0090] FIG. 23( a )- 23 ( c ) shows that rate of cell cycle progression were treated with benzopyran-4-one derivatives for 9 hrs.
[0091] FIG. 23( a ) illustrates the effects of control group.
[0092] FIG. 23( b ) illustrates the effects of compound I-1.
[0093] FIG. 23( c ) illustrates the effects of compound II-1.
[0094] FIGS. 24( a )- 24 ( e ) show that number of labeled DNA replication.
[0095] FIG. 24( a ) illustrates the effects of DMSO group.
[0096] FIG. 24( b ) illustrates the effects of Hydroxyurea (HU) group.
[0097] FIG. 24( c ) illustrates the effects of ku55933 group.
[0098] FIG. 24( d ) illustrates the effects of compound I-1.
[0099] FIG. 24( e ) illustrates the effects of compound II-1.
[0100] FIG. 25 illustrates the percentage of EdU incorporation.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0101] Further embodiments herein may be formed by supplementing an embodiment with one or more element from any one or more other embodiment herein, and/or substituting one or more element from one embodiment with one or more element from one or more other embodiment herein.
EXAMPLES
[0102] The following non-limiting examples are provided to illustrate particular embodiments. The embodiments throughout may be supplemented with one or more detail from one or more example below, and/or one or more element from an embodiment may be substituted with one or more detail from one or more example below.
[0103] Ataxia telangiectasia-mutated (ATM) and ATM and Rad3-related (ATR) are 2 members of the phosphoinositide 3-kinase (PI3K)-related protein kinases family that play a central role in DNA damage response (DDR) coordination; they also function in the signaling cascades machinery of cell cycle arrest, DNA repair and transcription, and cell death. While ATM is predominant activated in response to DNA strand breaks, ATR is activated in response to damage arising from ultraviolet (UV) ray or replication block; both kinases activate signaling cascades that involving 2 checkpoint kinases effectors, Chk1 and Chk2, whose roles were previously suggested to be redundant. In contrast to ATM, ATR has been reported to be indispensible for cell growth and for life. ATR-knockout mouse embryos died early due to mitotic catastrophe characterized by incomplete DNA replication and chromosomal fragmentation. Moreover, ATR gene mutations are rarely found in humans. The only mutated variants that can survive are heterozygous or hypomorphic variants. Furthermore, cells derived from patients with Seckel syndrome exhibit cellular features associated with ATR signaling cascades defects. Consistent with this phenotype, seckel-like mouse embryonic cells showed accelerated aging due to replicative stress, exhibiting an accumulation of lethal chromosomal breaks. However, with regard to its role in regulating the replication checkpoint, ATR is activated by most cancer chemotherapeutic agents that target DNA in replicating cells. Therefore, inhibition of ATR signaling cascades is a valid and promising strategy that can improve chemotherapeutic or radiotherapeutic efficiency.
[0104] Thus so far, several inhibitors of DDR-related kinases, including Chk1 and Chk2, have been successfully used alone or in combination with each other in clinical trials. Recently, several chemicals that inhibit ATR kinase activity in vitro were used to support the hypothesis that ATR kinase can be targeted to improve cancer therapy. Since most of these studies are in their initial stages, it is imperative to focus more efforts toward investigating strategies to inhibit ATR signaling cascades.
[0105] In accordance with an aspect of the present invention, benzopyran-4-one derivatives compound, characteristically with inhibiting of DNA Damage Response (DDR), is provided.
[0106] Another aspect of this invention, pharmaceutical composition of benzopyran-4-one derivatives, characteristically with inhibiting of DNA Damage Response (DDR), is provided. The benzopyran-4-one derivatives includes a common structure being the following formula I or formula II,
[0000]
wherein: R 3 , R 5 , R 7 , R 11 , R 14 and R 16 are selected independently from a group consisting of a hydrogen, a hydroxyl group, a methoxyl group and a oxygen atom contain a double bond. R 21 is selected independently from a group consisting of a hydrogen, a hydroxyl group and a methoxyl group.
[0108] In a further aspect of this invention is directed towards a method of treating cancer in a subject in need thereof, including the sequential or simultaneous co-administration of a compound of benzopyran-4-one derivatives or a pharmaceutically acceptable salt thereof, and a DNA-damaging agents. In some embodiments, the DNA-damaging agents are selected from chemotherapeutic drugs such as alkylating agents, antimetabolic agents, antibiotic anti-cancer agents, Topoisomerase inhibitors and anti-mitosis agents.
[0109] In some embodiments, the alkylating agent is one selected from Nitrogen mustards (eg. Melphalan, mechlorethamine, Chlorambucil, Ifosfamide, Cyclophosphamide, Estramustine and phenoxybenzamine); or Aziridines (eg. Thiotepa, Carboquone); or Nitrosoureas (eg. Carmustine, Semustine, Iomustine, Nimustine, Streptozocin, Ranimustine and Lomustine); or Procarbazine and triazenes (eg. Dacarbazine, Temozolomide and Procarbazine); or Alkyl sulfonate (eg. Busulfan); or Platinum coordination complex (eg. Cisplatin, Carboplatin, Nedaplatin, Iproplatin and Oxaliplatin); and mixtures thereof.
[0110] In some embodiments, the antimetabolic agent is one selected from Thymidylate synthase inhibitor (eg. Aminopterin, Methotrexate, Tegafur, Piritrexin, Trimetrexate, Floxuridine, Raltitrexed, Pemetrexed, Fluorouracil, Doxifluridine and Capecitabine); or Amidophosphoribosyl transferase inhibitors (eg. Mercaptopurine, Thioguanine and Thionosine); or DNA chain elongation inhibitors (eg. Cytarabine, Ancitabine, Gemcitabine, Fludarabine, Cladribine, Clofarabine, Azaserine, Azacitidine, Pentostatin, Hydroxyurea); and mixtures thereof.
[0111] In some embodiments, the antibiotic anti-cancer agent is one selected from free radical agents (eg. Bleomycin and Actinomycin D); or Topoisomerase II inhibitors (eg. Daunorubicin, Doxorubicin, Idarubicin, Epirubicin, valrubicin, Pirarubicin, Aclarubicin, Mitoxantrone and Piroxanthrone); or other therapies or anticancer agents (eg. Menogaril, Plicamycin, Acivicin, Anthramycin, Pentostatin, Calicheamicin and Peplomycin); and mixtures thereof.
[0112] In some embodiments, the Topoisomerase inhibitor is one selected from Topoisomerase I inhibitors (eg. Camptothecin, Irinotecan, Topotecan); or Topoisomerase II (eg. Podophyllin, Podophyllotoxin, Etoposide, Teniposide); and mixtures thereof.
[0113] In some embodiments, the anti-mitosis agent is one selected from Paclitaxel and Docetaxel; or anti-microtubule agents (eg. Colchicine, Vinblastine, Vincristine, Vindesine and Vinorelbine); and mixtures thereof.
[0114] Benzopyran-4-one derivatives compounds of this invention include Protoapigenone (I-1), 5′,6′-dihydro-6′-methoxy-protoapigenone (I-2), Protoapigenin, (I-3), protoflavonone (I-4), 5-hydroxyprotoflavone (I-5), 5-hydroxy-7-methoxy-protoflavonone (I-6), compounds I-7, compounds I-8, 3-(1-hydroxy-4-oxocyclohexa-2,5-dienyl)-1-H-benzo[f]chromen-1-one (II-1) and compounds II-2.
[0115] In a further aspect of this invention, pharmaceutical composition of benzopyran-4-one derivatives, characteristically with modulating the activation state of ATM kinase is provided. The benzopyran-4-one derivatives includes a common structure being the following formula I or formula II,
[0000]
[0116] In a further aspect of this invention, both assay kit and assay composition of benzopyran-4-one derivatives, characteristically with detecting the activation state of ATR, DNA DDR kinase signaling cascades is provided.
[0117] In a further aspect of this invention is directed towards a method of analyzeing ATR, DNA DDR kinase signaling cascades in a reaction site thereof, including the sequential or simultaneous of benzopyran-4-one derivatives compound or a pharmaceutically acceptable salt thereof, and a chemotherapeutic drugs or additional agents. In some embodiments, the chemotherapeutic drug is selected from chemotherapeutic drugs such as alkylating agents, antimetabolic agents, antibiotic anti-cancer agents, Topoisomerase inhibitors and anti-mitosis agents.
[0118] In some embodiments, the individual components of the combination may be administered separately, at different times during the course of therapy, or concurrently, in divided or single combination forms. Also provided is, for example, simultaneous, staggered, or alternating treatment.
[0119] In a further aspect of this invention, compounds and pharmaceutical composition of benzopyran-4-one derivatives, characteristically with detecting of DNA damage in cancer cell as determined by the activation state of ATM kinase is also useful for monitoring therapeutic effects during treatment.
[0120] In some embodiments, method using benzopyran-4-one derivatives compound or pharmaceutical composition for defecting in the ATR signaling cascade and/or DNA-damage response (DDR). In some embodiments, the defect is altered expression or activity of one or more of the following cell markers as determined by standard cell marker detection assays: ATM, CHK1, CHK2, cellular tumor antigen p53, Adenosine monophosphate activated protein kinase (AMPK), mammalian target of rapamycin complex (mTORC) 1, metal response element (MRE) 11, mitogen-activated protein kinase (MAPK), MAPK-activated protein kinase (MAPKAPK) 2, DNA Repair Protein (RAD50), Nijmegen breakage syndrome (NBS) 1, 53BP1, mediator of DNA damage checkpoint (MDC) 1, H2A histone family member X (H2AX).
[0121] In another embodiment, the cell is a cancer cell expressing DNA damaging oncogenes. In some embodiments, the cancer cell has altered expression or activity of one or more of the following cell markers as determined by standard cell marker detection assays: K-Ras, N-Ras, H-Ras, Raf, Myc, Mos, E2F, Cdc25A, CDC4, CDK2, Cyclin E, Cyclin A and Rb.
[0122] In a further embodiment, the invention relates to an assay kit or assay composition for determent of ATR and/or DNA DDR signaling cascades at reaction site. In particular the assay kit or assay composition can include, a benzopyran-4-one derivatives compound, a processing/handling plan, a compartment, a additional reagent and instructions for use, or a reagent with a compartment and instructions for use. In one embodiment, for the purpose of altered expression or activity can then generate a detectable at the reaction site of the immunocomplex.
[0123] The additional reagent can include ATR, the ATR receptor, the complex of DNA, or an antigenic fragment thereof, a binding composition, or a nucleic acid. A kit for determining the binding of a test compound, e.g., acquired from a biological sample or from a chemical library, can include a control compound, a labeled compound, and a method for separating free labeled compound from bound labeled compound and a combination thereof.
[0124] The term excipients or “pharmaceutically acceptable carrier or excipients” and “bio-available carriers or excipients” above-mentioned include any appropriate compounds known to be used for preparing the dosage form, such as the solvent, the dispersing agent, the coating, the anti-bacterial or anti-fungal agent and the preserving agent or the delayed absorbent. Usually, such kind of carrier or excipient does not have the therapeutic activity itself. Each formulation prepared by combining the derivatives disclosed in the present invention and the pharmaceutically acceptable carriers or excipients will not cause the undesired effect, allergy or other inappropriate effects while being administered to human. Accordingly, the derivatives disclosed in the present invention in combination with the pharmaceutically acceptable carrier or excipients are adaptable in the clinical usage and in the human. A therapeutic effect can be achieved by using the dosage form in the present invention by the local or sublingual administration via the venous, oral, and inhalation routes or via the nasal, rectal and vaginal routes. About 0.1 mg to 1000 mg per day of the active ingredient is administered for the patients of various diseases.
[0125] The carrier is varied with each formulation, and the sterile injection composition can be dissolved or suspended in the non-toxic intravenous injection diluents or solvent such as 1,3-butanediol. Among these carriers, the acceptable carrier may be mannitol or water. Besides, the fixing oil or the synthetic glycerol ester or di-glycerol ester is the commonly used solvent. The fatty acid such as the oleic acid, the olive oil or the castor oil and the glycerol ester derivatives thereof, especially the oxy-acetylated type, may serve as the oil for preparing the injection and as the naturally pharmaceutical acceptable oil. Such oil solution or suspension may include the long chain alcohol diluents or the dispersing agent, the carboxylmethyl cellulose or the analogous dispersing agent. Other carriers are common surfactant such as Tween and Spans or other analogous emulsion, or the pharmaceutically acceptable solid, liquid or other bio-available enhancing agent used for developing the formulation that used in the pharmaceutical industry.
[0126] The composition for oral administration adopts any oral acceptable formulation, which includes capsule, tablet, pill, emulsion, aqueous suspension, dispersing agent and solvent. The carrier generally used in the oral formulation, taking a tablet as an example, the carrier may be lactose, corn starch and lubricant, and magnesium stearate is the basic additive. The excipients used in a capsule include lactose and dried corn starch. For preparing an aqueous suspension or an emulsion formulation, the active ingredient is suspended or dissolved in oil interface in combination with the emulsion or the suspending agent, and appropriate amount of sweetening agent, flavors or pigment is added as needed.
[0127] The nasal aerosol or inhalation composition may be prepared according to the well-known preparation techniques. For example, the bioavailability can be increased by dissolving the composition in the phosphate buffer saline and adding the benzyl alcohol or other appropriate preservative, or the absorption enhancing agent. The compound of the present invention may be formulated as suppositories for rectal or virginal administration.
[0128] The compound of the present invention can also be administered intravenously, as well as subcutaneously, parentally, muscular, or by the intra-articular, intracranial, intra-articular fluid and intra-spinal injections, the aortic injection, the sterna injection, the intra-lesion injection or other appropriate administrations.
[0129] Protoapigenone (I-1) induces chromosomal aberrations but does not produce marked DDR.
[0130] Previously, Protoapigenone (I-1) and compound II-1 were demonstrated to cause DNA strand breaks and apoptosis in lung and prostate cancers (Chen H M, et al., Free Radic Biol Med 2011), suggesting that inducing DNA damage may be the potential mechanism underlying the anticancer effect of benzopyran-4-one derivatives.
[0131] To test this hypothesis, it is investigated the cytogenetic effect of Protoapigenone (I-1) on CHO cells ( FIG. 1 ). According to the Table 1, low Protoapigenone (I-1) concentrations produced dose-dependent increases in chromosomal structural changes, such as breakages, radials, and chromosomal polyploidy, similar to the effects seen with mitomycin C treatment; however, the complete mitotic chromosome could not be obtained upon high-dose Protoapigenone (I-1) treatment.
[0000]
TABLE 1
Protoapigenone (I-1) induces chromosomal aberration in CHO cells
DMSO
Protoapigenone
mitomycin
Treatment
control
(I-1)
C
Concentration (μM)
0.00
2.17
4.35
2.00
chromatid break (No.)
0
2
1
2
Chromatid deletion
0
0
1
3
Triradial
0
4
13
42
quadriradial
0
3
9
29
ring
0
1
2
0
complex rerrangement
0
0
0
2
dicentric
0
0
0
1
polyploid
1
3
1
0
pulverized cell
0
0
1
5
Average aberrant
0.5
6.5 *
14.0 *
42.0 *
metaphases (%) a
Note:
1. Two hundred cells per treatment were analysized for chromosomal aberration.
2. Type of structural aberrations, such as chromatid break, chromatid deletion, triradial, quadriradial, ring, complex rerrangement, dicentric, polyploid and pulverized cell numbers (No.) were indicated.
3. Others chromosome gap, chromosome break, chromosome deletion and chromatid gap were not be observed in this experiment.
4. a , * indicated statistic significantly for tested vs. control group by t-test.
[0132] Since mitomycin C can induce DDR in many cancers, it is investigated what kind of DDR signaling was activated by Protoapigenone (I-1). Surprisingly, high doses of Protoapigenone (I-1) in HEK293T cells did not induce noticeable changes in the putative DDR signaling, which it is measured by analyzing the phosphorylation of the ATM-dependent Chk2 Thr 68 residue and the ATR-dependent Chk1 Ser 345 residue ( FIG. 2 ). It did observe that Protoapigenone (I-1) treatment caused slight accumulation of the p53 protein, which could have been the result of several posttranslational modifications. However, phosphorylation of the p53 Ser 15 residue did not contribute to this Protoapigenone (I-1)-induced p53 protein accumulation, suggesting that Protoapigenone (I-1) does not directly damage DNA because DNA damage normally stimulates ATM/ATR-dependent p53 Ser15 phosphorylation. Our result is similar to previous reports that p38 MAPK is activated by Protoapigenone (I-1) (Chen W Y, et al. Invest New Drugs 2011), as its downstream target MAPKAPK2 was found to be phosphorylated starting as early as 2 h after Protoapigenone (I-1) exposure ( FIG. 2 ). It is repeated the benzopyran-4-one derivatives experiment on lung and breast carcinoma cell lines A549 and MDA-MB-231 cells, respectively, and obtained similar results. Consistently, no marked changes in Chk1 and Chk2 phosphorylation signaling were detected even at high doses of either drug for as long as 8 h after drug treatment ( FIGS. 3( a ) and 3 ( b )). The cytotoxic effect by benzopyran-4-one derivatives on cancer cells was determined by MTT assay at 48 h of incubation ( FIG. 4) ; our data indicated that the IC 50 value range for cytotoxicity was similar to those in previous reports, confirming that benzopyran-4-one derivatives are stable compounds that do not directly cause DNA damage.
[0133] Protoapigenone (I-1) and compound II-1 inhibit Chk1 phosphorylation after DNA damage.
[0134] Understanding the mechanism by which the benzopyran-4-one derivatives compounds cause chromosomal breakages ( FIG. 1 ) and other abnormalities might aid in identifying their targets. It is hypothesized that genes with functions associated with DNA damage checkpoints and/or DNA repair might be targeted by benzopyran-4-one derivatives. To test this hypothesis, it is assessed the effects of benzopyran-4-one derivatives on DDR induced by H 2 O 2 . Protoapigenone (I-1) was found to inhibit Chk1, but promote Chk2 phosphorylation in A594 cells treated with 0.1 mM H 2 O 2 for 2 h; however, ATM autophosphorylation was not affected ( FIG. 5( a )). Pretreatment of cells with okadaic acid (OA) (a phosphatase inhibitor) or MG132 (a proteasome inhibitor) could not reverse the Protoapigenone (I-1)-induced inhibition of Chk1 phosphorylation, indicating that the inhibition does not occur due to phosphatase activation or proteasome degradation by other regulatory factors ( FIG. 5( b )). Further, it is investigated other sources of DNA stimuli specific for ATR activation; our results demonstrate that UV-induced Chk1 phosphorylation was dose-dependently inhibited by benzopyran-4-one derivatives within different cells ( FIGS. 6( a ) and 6 ( b )). In response to DNA double-strand breaks (DSBs), FANCD2 is known to be monoubiquitinated on K561 (FANCD2-Ub) in an ATR-dependent manner to stimulate repair (Andreassen P R, et al. Genes Dev 2004). It is showed that FANCD2-Ub was also inhibited by benzopyran-4-one derivatives ( FIGS. 5( a ), 6 ( a ) and 6 ( b )); further, ATR inhibition by benzopyran-4-one derivatives was also observed in cells treated with currently prescribed chemotherapeutic agents ( FIG. 7) . Collectively, these findings indicate that benzopyran-4-one derivatives can modify ATR signaling after various types of DNA damage. Interestingly, compound II-1 was more potent than Protoapigenone (I-1) in inhibiting Chk1 phosphorylation and cytotoxicity ( FIGS. 4 , 6 ( a ) and 6 ( b )).
[0135] It is speculated that the replacement of 2 hydroxyl groups on Protoapigenone (I-1) with an additional benzene ring contributes positively to this ATR inhibition; however, the definite pharmacophores need to be further investigated when the ATR protein structure is resolved.
[0136] Target specificity of Protoapigenone (I-1) and compound II-1 for ATR-mediated signaling inhibition.
[0137] To elucidate the specificity of the benzopyran-4-one derivatives inhibition on ATR-mediated signaling, it is compared the change between cells treated with benzopyran-4-one derivatives or the ATM-specific inhibitor KU55933 before the induction of DDR. After H 2 O 2 damage, ATM is thought to be the principal responder, and KU55933 treatment strongly inhibited ATM-mediated Chk2 phosphorylation specifically, but its effect on ATR-mediated Chk1 phosphorylation was small ( FIG. 8( a )). In contrast, after hydroxyurea (HU; a replication blocker) damage, ATR is thought to be the principal responder, and benzopyran-4-one derivatives treatment significantly inhibited Chk1 phosphorylation, but only slightly inhibited Chk2 phosphorylation ( FIG. 8( b )).
[0138] Using these pharmacological methods, it is demonstrated that the specificity of DDR inhibition between benzopyran-4-one derivatives and KU55933 was completely different. To strengthen the argument that benzopyran-4-one derivatives specifically inhibits ATR signaling, small inhibitory RNAs against ATM, ATR, and the catalytic subunit of DNA protein kinase (DNA-PKcs) were introduced into HEK293T cells before exposure to UV or H 2 O 2 .
[0139] Our results demonstrated that benzopyran-4-one derivatives completely inhibited UV-induced or H 2 O 2 -induced Chk1 phosphorylation in a manner similar to siRNA knockdown of ATR, but not ATM or DNA-PKcs ( FIG. 9 , FIGS. 10( a ), 10 ( b ) and 10 ( c )). The siRNAs against ATM and DNA-PKcs decreased the UV-induced or H 2 O 2 -induced Chk2 phosphorylation, which were not altered by the addition of Protoapigenone (I-1), but were increased by compound II-1 treatment. Interestingly, neither siRNA targeted to ATM or ATR nor DNA-PKcs affected the compound II-1-mediated increase in Chk2 phosphorylation. Since a high dose of compound II-1 itself slightly induces Chk2 activation ( FIGS. 3( a ) and 3 ( b )), the increased Chk2 phosphorylation was likely a synergistic effect due to DNA damage.
[0140] To further identify the specific mediator that contributes to the effect of Protoapigenone (I-1) on the initiation of ATR kinase activation, it is tested whether TopBp1, ATRIP, and claspin were involved, as they have been identified as mediators of ATR kinase activation (Lopez-Contreras A J, et al. DNA Repair (Amst) 2010). Our results demonstrated that overexpression of ATRIP or TopBP1 did not reverse the inhibitory effect of Protoapigenone (I-1) on Chk1 phosphorylation, whereas overexpression of claspin or ATR did ( FIG. 11 ), suggesting that Protoapigenone (I-1) might affect the function of ATR or claspin contributes to ATR signaling inhibition.
[0141] Protoapigenone (I-1) and compound II-1 impair the functions of DNA damage checkpoints and DNA repair.
[0142] Previously, it has been demonstrated that S/M and G2/M checkpoints are activated by ATR in response to different types of DNA damage (Nghiem P, et al. Proc Natl Acad Sci USA 2001). Of these, the G2/M checkpoint involves ATM and ATR in collaboration, whereas the S/M checkpoint is mediated solely by ATR. To maintain genetic integrity, ATR can prevent premature mitotic entry in the event of incomplete DNA replication or unrepaired DNA damage. In order to evaluate the effect of benzopyran-4-one derivatives on these ATR-associated DNA damage checkpoints, it is observed the effect of benzopyran-4-one derivatives on mitotic entry following hydroxyurea or cisplatin treatment. In MDA-MB-231 cells, hydroxyurea and cisplatin significantly decreased the number of mitotic cells, indicating that the S/M and G2/M checkpoints are intact in MDA-MB-231 cells ( FIG. 12( a )).
[0000]
TABLE 2
The percentage of mitotic cells
Control
Compound
group
I-1
II-1
KU55933
Control
20.28 ± 0.86
23.69 ± 0.94
12.05 ± 0.68
20.29 ± 1.48
group
hydroxy-
4.46 ± 0.67
3.40 ± 0.41
10.49 ± 1.17
11.19 ± 0.76
urea
cisplatin
5.35 ± 0.07
7.99 ± 0.91
8.14 ± 0.99
9.70 ± 0.25
[0143] Benzopyran-4-one derivatives or KU55933 treatment increased the percentage of mitotic cells in cisplatin-treated cells, as the Table 2 suggesting that all of these compounds inhibited the damage-induced G2/M checkpoint. However, benzopyran-4-one derivatives, but not KU55933, significantly increased the HU-induced mitotic entry that is specific for the S/M checkpoint, indicating that benzopyran-4-one derivatives specifically impaired this distinctive checkpoint mediated solely by ATR ( FIG. 12( a )).
[0144] ATR function is also linked to DNA repair via its coupled targets (Sorensen C S, et al. Nat Cell Biol 2005). To examine the effect of benzopyran-4-one derivatives treatment on DNA repair, it is performed a homologous recombination repair (HRR) assay in HeLa cells.
[0000]
TABLE 3
The percentage of GFP cell (DNA homologous
recombination repair assay)
treatment
GFP cell (%)
Un-treatment group
0.0 μM
0.040 ± 0.0097
chromosomal breaks
Un-treatment
0.0 μM
1.217 ± 0.0203
generated by I-SceI
Compound I-1
2.0 μM
0.807 ± 0.0403
endonuclease
4.0 μM
0.213 ± 0.0105
expression group
Compound II-1
0.2 μM
0.703 ± 0.0304
0.4 μM
0.017 ± 0.0169
[0145] Our result, as Table 3 demonstrated that chromosomal breaks normally repaired by HRR were dose-dependently inhibited by Protoapigenone (I-1) at low concentrations. Compound II-1 produced similar effects at doses that were 10-fold lower than that of Protoapigenone (I-1) ( FIG. 12( b )). From these results, it is assumed that the cells carrying unrepaired DNA would enter into mitosis following DNA damage. To verify this assumption, it is analyzed the DNA-damage marker gamma-H2AX on mitotic cells using immunofluorescence staining. As expected, the numbers of large gamma-H2AX foci were increased upon addition of benzopyran-4-one derivatives in both unperturbed and perturbed mitotic cells ( FIG. 13) , suggesting that benzopyran-4-one derivatives increase DNA damage in mitotic cells. The chromosomes became flat and aggregated after benzopyran-4-one derivatives treatment, differing from the three-dimensional and hair-like appearance of normal chromosomes at metaphase.
[0146] Protoapigenone (I-1) and compound II-1 enhance chemosensitivity.
[0147] Inhibition of the checkpoint and repair mechanisms leads to chemosensitization in cancers. It is questioned whether benzopyran-4-one derivatives could function as sensitizers for the chemotherapeutic drugs cisplatin that has been shown to induce ATR activation as well as FANCD2 monoubiquitination, which is the vital step for DNA crosslink repair (Chirnomas D, et al. Mol Cancer Ther 2006). It is found that benzopyran-4-one derivatives treatment decreased the cisplatin-induced Chk1 phosphorylation and FANCD2 monoubiquitination in A549, MDA-MB-231, and U2OS cells ( FIGS. 14( a ), 14 ( b ) and 14 ( c )). Using the same doses, compound II-1 not only inhibits monoubiquitination of FANCD2 but also affects FANCD2 protein stability; this data emphasizes that compound II-1 has more potent inhibitory effects as compared to Protoapigenone (I-1). It is further treated individual cells with cisplatin in combination with several varying doses of benzopyran-4-one derivatives, and counted survival colonies to determine their ability to survive after cisplatin-induced damage. Our results demonstrated that benzopyran-4-one derivatives effectively decreased the clonogenic survival in cisplatin-treated MDA-MB-231 and A549 cells in the nanomolar dose range ( FIG. 15( a ), 15 ( b ), FIGS. 16( a ) and 16 ( b )). To investigate the chemosensitization effect of low-dose benzopyran-4-one derivatives in vivo, it is established a tumor xenograft in nude mice using human MDA-MB-231 tumor cells, which are considered to be more resistant to cisplatin and are also sensitive to treatment with benzopyran-4-one derivatives, at least as compared to A549 cells ( FIG. 4 , FIGS. 17( a ) and 17 ( b )). When the mice were treated with 0.2 mg/kg compound II-1 in combination with 2 mg/kg cisplatin, the tumor inhibitory effect was greater than that of cisplatin treatment alone ( FIG. 18) . However, Protoapigenone (I-1) unexpectedly did not affect the cisplatin sensitivity of MDA-MB-231 tumors when a higher dose of 2 mg/kg was used in our experiments (data not shown). The pharmacokinetic data of Protoapigenone (I-1) and compound II-1 needs to be compared in future studies to determine the differences in the chemical effects of these 2 compounds in vitro and in vivo.
[0148] ATR are involved in DNA replication. Low doses of Protoapigenone (I-1) and compound II-1 significantly slowed cancer growth in a dose-dependent manner ( FIG. 19( a ), 19 ( b ) FIGS. 20( a ) and 20 ( b )), and caused S phase delay and inhibition of DNA synthesis ( FIG. 22( a ), 22 ( b ), 22 ( c ), FIG. 23( a ), 23 ( b ) and 23 ( c )); these events are similar to previously reported characteristics of ATR defects. In the results of double-thymidine cell cycle synchronization assay, according to the Table 4 which sorted out from FIG. 21-23 , the unsynchronized cells ( FIG. 21( a )) become synchronization by using this method, and 97% of cells were stopped at G1/S boundary after two cycles of thymidine blocks ( FIG. 21( b )). Those synchronized cells released from thymidine blockade and allowed progress into S phase in presence or absence of protoapigenone (I-1) and compound II-1. Protoapigenone (I-1) ( FIGS. 22( b ) and 23 ( c )) and compound II-1 ( FIGS. 22( c ) and 23 ( c )) showed significantly reduce the percentage of G2/M cells at 9 hours of treatment in compared with control group ( FIGS. 22( a ) and 23 ( a )). So far, indicating that benzopyran-4-one derivatives with the ability to delay the S phase progression.
[0149] Through EdU (5-ethynyl-2′-deoxyuridine) incorporation to measurement the capacity of DNA replication, 4 μM protoapigenone (I-1) ( FIGS. 24( d )) and 0.4 μM compound II-1 ( FIG. 24( e )) but not 10 μM ATM inhibitor KU55933 ( FIG. 24(C) ) showed efficiently reduce the percentage of incorporation in compared with control group ( FIG. 24( a )), indicating that DNA replication is inhibited ( FIG. 25) ; these events are similar to the effect of a DNA replication blocker Hydroxyurea (HU) ( FIG. 24( b )) and visualized that benzopyran-4-one derivatives with the ability to inhibit the DNA replication.
[0000]
TABLE 4
cell cycle
G1
S
G2M
unsynchronized cells
42.51%
30.26%
24.75%
initiation (0 hrs)
Control
70.95%
24.00%
1.29%
release
6 hrs
Control
18.29%
75.63%
0.63%
synchronizeation
I-1
25.45%
69.13%
0.41%
II-1
21.72%
72.01%
4.59%
9 hrs
Control
20.94%
25.53%
53.54%
I-1
21.41%
60.89%
16.46%
II-1
15.50%
63.06%
20.45%
[0150] Materials and Methods
[0151] Antibodies
[0152] Primary antibodies of Chk1 (sc-8408), Chk2 (sc-17747), FANCD2 (SC-20022), phospho-ATM Ser1981 (sc-47739), and Myc (sc-40) were purchased from Santa Cruz. Phospho-histone H3 Ser10 (06-570) and H2AX Ser139 (05-636) antibodies were purchased from Millipore. Claspin (2880) and phospho-Chk1 Ser345 (2348), phospho-Chk2 Thr68 (2661), phospho-P53 Ser15 (9286), P38 MAPK Thr180/Tyr182 (9216), and MAPKAPK2 Thr334 (3007) were purchased from Cell Signaling. Actin (A2066), flag (F 1804), and hemagglutinin (H9658) antibodies were purchased from Sigma-Aldrich. ATR (A300-137A), ATRIP (A300-095A), and TopBP1 (A300-111A) antibodies were purchased from Bethyl; and anti-ATM (GTX70103) antibodies were purchased from Gene Tex.
[0153] Cell Culture and Treatment
[0154] MDA-MB-231 (breast adenocarcinoma; ATCC HTB-26, BCRC 60425) and A549 (lung adenocarcinoma; ATCC CCL-185, BCRC 60074) human cell lines were purchased from Bioresource Collection and Research Center (BCRC, Hsinchu, Taiwan), and were authenticated by American Type Culture Collection (ATCC, Manassas, Va.). U2OS (osteosarcoma), HeLa (cervical adenocarcinoma), and HEK 293T (embryonic kidney cells) human cell lines were provided by Dr. Sheau-Yann Shieh (Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan). Cells were maintained in Dulbecco's modified Eagle's medium (DMEM, Sigma-Aldrich) supplemented with 10% fetal bovine serum (FBS) (Gibco). For DDR induction, freshly diluted H 2 O 2 (Merck) was added to the culture medium 1 h before the cells were harvested. For UV irradiation treatment, the cells were irradiated for 10 J/m 2 by a cross-linker (UVP) 1 h prior to analysis. Protoapigenone (I-1) and compound II-1 were isolated and synthesized as described previously (15-17).
[0155] In Vitro Chemosensitization Assay
[0156] To evaluate in vitro chemosensitization, cells were seeded in 6-well plates 1 d before the experiment at a density of 100-400 cells/well. The drugs were incubated with the cells for 6 h, after which the medium was replaced with fresh drug-free FBS-containing medium. The colonies became visible and were counted 7-10 d later using 0.1% crystal violet staining following image capture by a CCD camera (LAS-4000 mini; Fujifilm).
[0157] Flow Cytometry
[0158] To evaluate the effect of DNA damage checkpoint activation on cell cycle distribution, the cells were harvested at indicated time points and fixed with methanol for at least 2 h. The DNA was then stained with a solution containing propidium iodide (PI) and RNase A (Sigma-Aldrich). Fluorescently labeled cells were subsequently analyzed by the flow cytometer (LSR II; BD Biosciences) with a suitable selection of excitation and emission wavelengths. The percentages of different fluorescent cell populations were analyzed using WinMDI Ver. 2.9 (The Scripps Research Institute).
[0159] DNA replication was measured using a Click-it EdU assay kit, which is based on incorporation of the thymidine analogue 5-ethynyl-2′-deoxyuridine (EdU) into DNA during replication (Invitrogen). Then, 10 μM EdU was added to the cell culture medium 30 min before the cells were harvested and fixed in 4% paraformaldehyde. After cycloaddition, EdU was detected with Alexa Fluor 647 using click reaction catalyzed by Cu (II), and the DNA content was stained by CellCycle 405-blue. To assay the mitotic entry, cells were treated with the indicated drugs and trapped in 70 nM nocodazole for 16 h, and antibodies against phospho-histone H3 Ser10 and PI were used to stain the mitotic cells and DNA content, respectively. An FITC Annexin V apoptosis detection kit was used to characterize the phenotype of cell death based on PI and Annexin V double staining (BD Pharmingen, San Diego, Calif.). Fluorescence-labeled cells were subsequently analyzed by the BD LSR II flow cytometer with a suitable selection of excitation and emission wavelengths. The percentages of different fluorescent cells were analyzed using WinMDI Ver. 2.9.
[0160] In Vitro Chromosome Aberration Test
[0161] In brief, 5×10 5 Chinese Hamster Ovary (CHO) cells were seeded in 60-mm dishes 1 d before the experiment. Protoapigenone (I-1)-induced structural chromosomal changes after 20 h were compared with that of the cells cultured in 2 μM mitomycin C. At 18 h after Protoapigenone (I-1), 0.1 μg/mL colchicine was added for 2 h, and metaphase cells were collected by shaking them off the dishes. Mitotic cells were treated with 0.5% KCl for 10 min and fixed with a 3:1 mixture of methanol: glacial acetic acid. The cells were then spread on slides for chromosome staining with 5% Giemsa solution. It is then analyzed the chromosome structure of 200 well-spread metaphase cells (100 metaphase cells/experiment) under a 100× oil immersion objective.
[0162] Plasmids and siRNAs
[0163] The plasmids ATR, ATRIP, and claspin were kindly provided by Dr. X. Wu (The Scripps Research Institute, La Jolla, Calif.), and TopBP1 was provided by Dr. J. Chen (University of Texas MD Anderson Cancer Center, Houston, Tex.). The siRNA sequences of the target ATM (5′-AAGCGCCTGATTCGAGATCCT-3′), ATR (5′-CCTCCGTGATGTTGCTTGATT-3′), DNA-PKcs (5′-GATCGCACCTTACTCTGTTGA-3′), and the random sequence that served as the control (5′-AAGTCAATATGCGACTGATGG-3′) were synthesized by Sigma-Proligo (23,24). All transfections in HEK293T cells were performed by the calcium phosphate precipitation method.
[0164] Western Immunoblotting.
[0165] Cell lysate preparations, gel electrophoresis, and immunoblotting were performed as previously described (23). The binding of primary antibodies were detected by horseradish peroxidase-coupled secondary antibodies (Jackson ImmunoResearch) followed by enhanced chemiluminescence (ECL)(Millipore). The images of non-saturated bands were captured using a luminescent image analyzer (LAS-4000 mini; Fujifilm). The antibodies used in this study are listed in supplementary materials.
[0166] DNA Homologous Recombination Repair Assay.
[0167] DNA constructs of the recombination substrate pHPRT-DRGFP, in which the I-SceI site lies within 1 copy of 2 mutated tandem repeated GFP genes, and the I-SceI endonuclease expression vector pCBASceI, were originally constructed by Dr. M. Jasin (25). In brief, it is generated a stable pHPRT-DRGFP construct in HeLa cells, and evaluated the chromosomal breaks generated by I-SceI endonuclease expression. Six hours after pCBASceI was delivered into the cells, complete medium with or without Protoapigenone (I-1) or compound II-1 was replaced onto the cells. Forty-eight hours after delivery, the efficiency of chromosomal HRR was obtained as the percentage of GFP-positive cells, which was assessed by flow cytometry.
[0168] Human Xenograft Tumors in Nude Mice.
[0169] Human breast cancer MAD-MB-231 cells were harvested from the culture, resuspended in medium without serum at 1×10 8 cells/mL, and 0.1 mL of this suspension was subcutaneously injected into the right flank of female nude mice (BALB/cAnN-Foxn1nu/Crl Narl; purchased from the National Science Council Animal Center, Taiwan). Tumor-injected mice that successfully developed tumors that grew to approximately 50-100 mm 3 in volume were randomly sorted into groups and used for the experiments. Control vehicle or 2 mg/kg of cisplatin with or without 0.2 mg/kg of compound II-1 was administered intraperitoneally every 4 d throughout the experiment.
Example 1
Preparation of the Composition in Tablet
[0170] Tablets are prepared using standard mixing and formation techniques as described in U.S. Pat. No. 5,358,941, to Bechard et al., issued Oct. 25, 1994, which is incorporated by reference herein in its entirety.
[0000]
Protoapigenone (I-1)
100 mg
Lactose
qs
Corn starch
qs
EMBODIMENTS
Embodiment 1
[0171] A inhibiting of DNA Damage Response composition including a benzopyran-4-one derivatives compound presented by formula I:
[0000]
wherein: R 3 , R 5 , R 7 , R 11 , R 14 and R 16 are selected independently from a group consisting of a hydrogen, a hydroxyl group, a methoxyl group and a oxygen atom contain a double bond.
Embodiment 2
[0173] A inhibiting of DNA Damage Response composition including a benzopyran-4-one derivatives compound presented by formula II:
[0000]
wherein: R 21 is selected independently from a group consisting of a hydrogen, a hydroxyl group and a methoxyl group.
Embodiment 3
[0175] A medical effect for inhibited ATR-mediated DNA damage checkpoint composition including an effective amount of being one compound selected from a group consisting of benzopyran-4-one derivatives represented by formula I and formula II.
Embodiment 4
[0176] A sensitizing effect for chemotherapeutic treatment composition including an effective amount of a compound selected from a group consisting of benzopyran-4-one derivatives represented by formula I and formula II.
Embodiment 5
[0177] A assay composition for providing assay for the state of DNA DDR signaling cascade, including an effective amount of a compound selected from a group consisting of benzopyran-4-one derivatives represented by formula I and formula II.
Embodiment 6
[0178] A pharmaceutical as above embodiments, therewith in a subject in need thereof including co-administration a compound of benzopyran-4-one derivatives; and at least one chemotherapeutic drugs against a cancer disease in need thereof.
Embodiment 7
[0179] A pharmaceutical as above embodiments, therewith the chemotherapeutic drugs includes one selected from an alkylating agent, an antimetabolic agents, an antibiotic anti-cancer agents, a Topoisomerase I, a Topoisomerase II, an anti-mitosis agents and a combination thereof.
Embodiment 8
[0180] A pharmaceutical as above embodiments, therewith the alkylating agent is one selected from Nitrogen mustards (eg. Melphalan, mechlorethamine, Chlorambucil, Ifosfamide, Cyclophosphamide, Estramustine and phenoxybenzamine); or Aziridines (eg. Thiotepa, Carboquone); or Nitrosoureas (eg. Carmustine, Semustine, Iomustine, Nimustine, Streptozocin, Ranimustine and Lomustine); or Procarbazine and triazenes (eg. Dacarbazine, Temozolomide and Procarbazine); or Alkyl sulfonate (eg. Busulfan); or Platinum coordination complex (eg. Cisplatin, Carboplatin, Nedaplatin, Iproplatin and Oxaliplatin); and a combination thereof.
Embodiment 9
[0181] A pharmaceutical as above embodiments, therewith the antimetabolic agent is one selected from Thymidylate synthase inhibitor (eg. Aminopterin, Methotrexate, Tegafur, Piritrexin, Trimetrexate, Floxuridine, Raltitrexed, Pemetrexed, Fluorouracil, Doxifluridine and Capecitabine); or Amidophosphoribosyl transferase inhibitors (eg. Mercaptopurine, Thioguanine and Thionosine); or DNA chain elongation inhibitors (eg. Cytarabine, Ancitabine, Gemcitabine, Fludarabine, Cladribine, Clofarabine, Azaserine, Azacitidine, Pentostatin, Hydroxyurea); and a combination thereof.
Embodiment 10
[0182] A pharmaceutical as above embodiments, therewith the antibiotic anti-cancer agent is one selected from free radical agents (eg. Bleomycin and Actinomycin D); or Topoisomerase II inhibitors (eg. Daunorubicin, Doxorubicin, Idarubicin, Epirubicin, valrubicin, Pirarubicin, Aclarubicin, Mitoxantrone and Piroxanthrone); or other therapies or anticancer agents (eg. Menogaril, Plicamycin, Acivicin, Anthramycin, Pentostatin, Calicheamicin and Peplomycin) and a combination thereof.
Embodiment 11
[0183] A pharmaceutical as above embodiments, therewith the Topoisomerase inhibitor is one selected from Topoisomerase I inhibitors (eg. Camptothecin, Irinotecan, Topotecan); or Topoisomerase II (eg. Podophyllin, Podophyllotoxin, Etoposide, Teniposide) and a combination thereof.
Embodiment 12
[0184] A pharmaceutical as above embodiments, therewith the anti-mitosis agent is one selected from Paclitaxel and Docetaxel; or anti-microtubule agents (eg. Colchicine, Vinblastine, Vincristine, Vindesine and Vinorelbine) and a combination thereof.
Embodiment 13
[0185] A method for sensitizing cells to DNA damaging agents, including steps of providing an effective amount of a benzopyran-4-one derivative; and administering the effective amount of the benzopyran-4-one derivative to a subject in need thereof.
Embodiment 14
[0186] A method for inhibiting a DNA damage response (DDR), including steps of providing an effective amount of a benzopyran-4-one derivative; and administering the effective amount of the benzopyran-4-one derivative to a subject in need thereof.
Embodiment 15
[0187] A method as above embodiments, wherein the benzopyran-4-one derivative is represented by formula I:
[0000]
wherein each of R 3 , R 5 , R 7 , R 11 , R 14 and R 16 is one selected from a group consisting of a hydrogen, a hydroxyl group, a methoxyl group and an oxygen atom containing a double bond.
Embodiment 16
[0189] A method as above embodiments, wherein the benzopyran-4-one derivative is represented by formula II:
[0000]
wherein R 21 is one selected from a group consisting of a hydrogen, a hydroxyl group and a methoxyl group.
Embodiment 17
[0191] A method as above embodiments, wherein the administering step further includes a step of co-administering the benzopyran-4-one derivative and at least one of chemotherapeutic drug against a cancer disease to the subject in need thereof.
Embodiment 18
[0192] A method as above embodiments, wherein the chemotherapeutic drugs include one selected from a group consisting of an alkylating agent, an antimetabolic agent, an antibiotic anti-cancer agent, a Topoisomerase I, a Topoisomerase II, an anti-mitosis agent and a combination thereof.
Embodiment 19
[0193] A method for inhibiting an ATR-mediated DNA damage checkpoint, including a step of administering to a subject in need thereof an effective amount of a compound being one of formula I and formula II,
[0000]
wherein each of R 3 , R 5 , R 7 , R 11 , R 14 , R 16 is one selected from a group consisting of a hydrogen, a hydroxyl group, a methoxyl group and an oxygen atom containing a double bond; wherein R 21 is one selected from a group consisting of a hydrogen, a hydroxyl group and a methoxyl group.
REFERENCES
[0000]
Andreassen P R, et al. ATR couples FANCD2 monoubiquitination to the DNA-damage response. Genes Dev 2004; 18(16):1958-63.
Chen H M, et al. A novel synthetic protoapigenone analogue, WYC02-9, induces DNA damage and apoptosis in DU145 prostate cancer cells through generation of reactive oxygen species. Free Radic Biol Med 2011; 50(9):1151-62.
Chen W Y, et al. Protoapigenone, a natural derivative of apigenin, induces mitogen-activated protein kinase-dependent apoptosis in human breast cancer cells associated with induction of oxidative stress and inhibition of glutathione S-transferase pi. Invest New Drugs 2011; 29(6):1347-59.
Chirnomas D, et al. Chemosensitization to cisplatin by inhibitors of the Fanconi anemia/BRCA pathway. Mol Cancer Ther 2006; 5(4):952-61.
Chiu C C, et al. Fern plant-derived protoapigenone leads to DNA damage, apoptosis, and G(2)/m arrest in lung cancer cell line H1299. DNA Cell Biol 2009; 28(10):501-6.
Lopez-Contreras A J, et al. The ATR barrier to replication-born DNA damage. DNA Repair (Amst) 2010; 9(12):1249-55.
Nghiem P, et al. ATR inhibition selectively sensitizes G1 checkpoint-deficient cells to lethal premature chromatin condensation. Proc Natl Acad Sci USA 2001; 98(16):9092-7.
Sorensen C S, et al. The cell-cycle checkpoint kinase Chk1 is required for mammalian homologous recombination repair. Nat Cell Biol 2005; 7(2): 195-201.
Wang H C, et al. Inhibition of ATR-dependent signaling by protoapigenone and its derivative sensitize cancer cells to interstrand cross-link-generating agents in vitro and in vivo. Mol Cancer Ther molcanther. Apr. 24, 2012; 1443
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This invention is announcing a composition of flavonoid skeleton in the formula I or formula II compound, wherein each of the substituents is given the definition as set forth in the specification and claims. This composition have the capacity to Inhibit functions of ATR and FANCD2 on DNA replication, damage checkpoint, and repair; therefore, this composition can improve the cancer sensitivity and poor prognosis to DNA-damaging therapeutics.
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REFERENCE TO RELATED APPLICATIONS
The present application is a divisional application of U.S. patent application Ser. No. 11/460,366 filed Jul. 27, 2006, now U.S. Pat. No. 7,553,615, which is based on and claims priority to German Patent Application No. 10 2005 035 469.6, filed Jul. 28, 2005, both of which references are hereby incorporated by reference in their entireties.
TECHNICAL FIELD
The invention concerns stable nicotinamide adenine dinucleotide (NAD/NADH) and nicotinamide adenine dinucleotide phosphate (NADP/NADPH) derivatives, enzyme complexes of these derivatives and their use in biochemical detection methods and reagent matrices.
BACKGROUND
Measuring systems for biochemical analytics are important components of clinically relevant analytical methods. This primarily concerns the measurement of analytes e.g. metabolites or substrates which are determined directly or indirectly with the aid of an enzyme. The analytes are converted with the aid of an enzyme-coenzyme complex and subsequently quantified. In this process the analyte to be determined is contacted with a suitable enzyme and a coenzyme where the enzyme is usually used in catalytic amounts. The coenzyme is changed e.g. oxidized or reduced by the enzymatic reaction. This process can be detected electrochemically or photometrically either directly or by means of a mediator. A calibration yields a direct correlation between the measured value and the concentration of the analyte to be determined.
Coenzymes are organic molecules which are covalently or non-covalently bound to an enzyme and are changed by the conversion of the analyte. Prominent examples of coenzymes are nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP) from which NADH or NADPH respectively are formed by reduction.
Measuring systems known from the prior art are characterized by a limited shelf-life and by special requirements for the environment such as cooling or dry storage in order to achieve this storage stability. Hence erroneous results caused by incorrect, unnoticed, faulty storage can occur for certain forms of application, e.g. in the cases of tests which are carried out by the end-users themselves such as blood glucose self-monitoring. Especially the exhaustion of desiccants due to opening the primary packaging for excessive periods can result in measuring errors which in some systems can be hardly recognized by the consumer.
A known measure that can be used to increase the stability of biochemical measuring systems is the use of stable enzymes, e.g. the use of enzymes from thermophilic organisms. It is also possible to stabilize enzymes by chemical modification, e.g. cross-linking or by mutagenesis. Furthermore, enzyme stabilizers such as trehalose, polyvinylpyrrolidone and serum albumin can also be added or the enzymes can be enclosed in polymer networks, e.g. by photopolymerization.
It has also been attempted to improve the storage life of biochemical measuring systems by using stable mediators. Thus the specificity of tests is increased and interferences during the reaction are eliminated by using mediators having the lowest possible redox potential. However, the redox potentials of the enzyme/coenzyme complexes constitutes a lower limit for the redox potential. If those fall below this limit, the reaction with the mediators is slowed down or even prevented.
Alternatively it is also possible to use biochemical measuring systems without mediators in which for example coenzymes such as the coenzyme NADH are directly detected. However, a disadvantage of such measuring systems is that coenzymes such as NAD and NADP are unstable.
NAD and NADP are base-labile molecules, the degradation paths of which are described in the literature (N. J. Oppenheimer in The Pyridine Nucleotide Coenzymes Academic Press, New York, London 1982, J. Everese, B. Anderson, K. You, Editors, chapter 3, pages 56-65). Essentially ADP-ribose is formed during the degradation of NAD or NADP by cleavage of the glycosyl bonds between the ribose and the pyridine unit. The reduced forms NADH and NADPH are, however, acid labile. For example, epimerization is a known degradation path. In both cases, the instability of NAD/NADP and NADH/NADPH is due to the liability of the glycosyl bonds between the ribose and the pyridine unit. But even under less drastic conditions such as in aqueous solution, the coenzymes NAD or NADP are already hydrolyzed solely by the ambient humidity. This instability can result in inaccuracies when measuring analytes.
A number of NAD/NADP derivatives are described for example in B. M. Anderson in the Pridine Nucleotide Coenzymes, Academic Press New York, London 1982, J. Everese, B. Anderson, K. You, Editors, Chapter 4. However, most of these derivatives are not accepted well by enzymes. The only derivative which has therefore been previously used for diagnostic tests is 3-acetylpyridine adenine dinucleotide (acetyl NAD) which was first described in 1956 (N. O. Kaplan, J. Biol. Chem . (1956) 221, 823). This coenzyme is also not accepted well by enzymes and exhibits a change in the redox potential.
The use of other NAD derivatives with a modified pyridine group is described in WO 01/94370. However, modifications of the nicotinamide group usually have a direct effect on the catalytic reaction. In most cases this effect is negative.
In another stabilization concept the ribose unit was modified in order to influence the stability of the glycosyl bond. This process does not directly interfere with the catalytic reaction of the nicotinamide group. However, there may be an indirect effect as soon as the enzyme binds strongly and specifically to the ribose unit. In this connection Kaufmann et al. disclose a number of thioribose-NAD derivatives in WO 98/33936 and U.S. Pat. No. 5,801,006 and WO 01/49247. However, a correlation between the modification of the nicotinamide ribose unit and the activity of the derivatives in enzymatic reactions has previously not been demonstrated.
CarbaNAD, a derivative without a glycosyl bond was described for the first time in 1988 (J. T. Slama, Biochemistry 1989, 27, 183 and Biochemistry 1989, 28, 7688). In this derivative the ribose is substituted by a carbacyclic sugar unit. Although carbaNAD was described as a substrate for dehydrogenases, its activity has not yet been proven in clinical biochemical detection methods.
A similar approach was described later by G. M. Blackburn, Chem. Comm., 1996, 2765 in order to synthesize carbaNAD with a methylene bisphosphonate compound instead of the natural pyrophosphate. The methylene bisphosphonate is more stable towards phosphatases and was used as an inhibitor for a ADP ribosylcyclase. The aim was not to make it more resistant to hydrolysis (J. T. Slama, G. M. Blackburn).
Hence the object of the present invention is to provide stable bioanalytical measuring systems especially for determining glucose which avoid the sensitivity to hydrolysis of NAD/NADP and at the same time are active as coenzymes in enzyme reactions.
SUMMARY
This object is achieved by a test element for determining an analyte comprising (i) a coenzyme-dependent enzyme or a substrate for such an enzyme and (ii) a compound of the following general formula (I), or a salt or optionally a reduced form thereof, as the coenzyme:
in which
A=adenine or an analog thereof; T=O or S; U=OH, SH, BH 3 —, or BCNH 2 —; V=OH or a phosphate group; W=COOR, CON(R) 2 , COR, or CSN(R) 2 , in which R denotes H or C 1 -C 2 alkyl; X1, X2=O, CH 2 , CHCH 3 , C(CH 3 ) 2 , NH, or NCH 3 ; Y=NH, S, O, or CH 2 ; Z=(i) a linear group containing 4-6 C atoms, for example 4 C atoms in which 1 or 2 C atoms are optionally replaced by one or more heteroatoms selected from O, S and N; or
(ii) a group comprising a cyclic compound containing 6 C atoms which optionally contains one or more heteroatoms selected from O, S and N and optionally one or more substituents, and a residue C(R4) 2 bound to the cyclic compound and to X2; where R4 denotes H, F, or CH 3 ;
provided that Z and the pyridine residue are not linked by a glycosidic bond.
In one embodiment, W=CONH 2 or COCH 3 .
Substituents on Z in another embodiment are selected from the group comprising OH, F, Cl and C 1 -C 2 alkyl which are optionally fluorinated or chlorinated and/or OH-substituted, O—C 1 -C 2 alkyl.
In another embodiment, a test element is used to determine glucose which comprises a glucose dehydrogenase and a compound of the general formula (I) as mentioned above or a salt thereof.
Surprisingly, the compounds according to the invention are stable towards hydrolysis and are good substrates in enzymatic detection methods and can be used for biochemical diagnostics. This finding is in contrast to that of most of the previously known NAD/NADP derivatives since these derivatives are usually stable for only very short periods in enzymatic detection methods.
Some observations of the compounds according to the invention compared to the prior art are:
higher stability, higher enzymatic activity, simpler and more efficient synthesis, they can be used in all previously known biochemical detection methods.
Some problems of the previously known biochemical detection methods can be largely avoided by the provision of stable NAD/NADP derivatives using the present invention, for example in combination with a stabilizing formulation such as, for example, by enclosing enzymes in polymer networks. Moreover, it is not necessary to use stabilizing additives. This is particularly advantageous since the lower the number of reactive substances involved, the greater is the chance of obtaining a stable formulation for the analyte determination.
The present invention provides test elements comprising a number of stable NAD/NADP derivatives which have an adequate enzymatic activity for use as a coenzyme on the test element.
Stable NAD/NADP derivatives can be produced in generally known processes of synthesis. For this, the amino group of a cyclic amino alcohol is converted into a pyridinium derivative by Zincke chemistry. The primary OH group is subsequently phosphorylated and coupled to an activated AMP derivative to form an NAD derivative. Alternatively, the primary OH group can also be firstly phosphorylated and then the amino group can be converted into a pyridine by means of the Zincke reaction.
Another synthetic route is to activate the primary alcohol to form a tosylate or iodide and subsequently alkylate ADP.
Other embodiments of a test element according to the invention comprise, for example, compounds having the following general formula (I′), or a salt or optionally a reduced form thereof:
in which
A=adenine or an analog thereof; T=O or S; U=OH, SH, BH 3 —, or BCNH 2 —; V=OH or a phosphate group; W=COOR, CON(R) 2 , COR, or CSN(R) 2 , in which R denotes H or C 1 -C 2 alkyl; X1, X2=O, CH 2 , CHCH 3 , C(CH 3 ) 2 , NH, or NCH 3 ; Y=NH, S, O, or CH 2 ; Z=a saturated or unsaturated carbocyclic or heterocyclic six-membered ring, such as a compound having the general formula (II):
in which a single or double bond can in each case independently be present between R1 and R2 or between R1′ and R2′, wherein if a single bond is present between R1 and R2 or R1′ and R2′ respectively:
R1, R1′=O, S, NCH 3 , NH, C(R4) 2 , CHOH, or CHOCH 3 , where R1 or R1′ cannot at the same time be a heteroatom, and R2, R2′=C(R4) 2 , CHOH, or CHOCH 3 ;
and wherein if a double bond is present between R1 and R2 or R1′ and R2′ respectively:
R1, R1′, R2, R2′=CR4, and R4=H, F, Cl, or CH 3 ; and
R6, R6′=CH or CCH 3 .
Compounds of the following formula (I″), or a salt or optionally a reduced form thereof, are another subject matter of the invention:
in which
A=adenine or an analog thereof; T=O or S; U=OH, SH, BH 3 —, or BCNH 2 —; V=OH or a phosphate group; W=COOR, CON(R) 2 , COR, or CSN(R) 2 , in which R=H or C 1 -C 2 alkyl; X1, X2=O, CH 2 , NH, or NCH 3 ; Y=NH, S, O, or CH 2 ; Z=(i) a linear group of the general formula
—(C(R4) 2 ) n
in which n=4-6, and R4=H, F, Cl, CH 3 , or CH 2 OH
provided that at least one residue U is BH 3 — or BCNH 2 —; or (ii) a saturated or unsaturated carbocyclic or heterocyclic six-membered ring, such as a compound of the general formula (II)
in which a single or double bond can in each case independently be present between R1 and R2 or between R1′ and R2′, wherein if a single bond is present between R1 and R2 or R1′ and R2′ respectively:
R1, R1′=O, S, NCH 3 , NH, C(R4) 2 , CHOH, or CHOCH 3 , where R1 or R1′ cannot at the same time be a heteroatom, and R2, R2′=C(R4) 2 , CHOH, CHOCH 3 ;
and wherein if a double bond is present between R1 and R2 or R1′ and R2′ respectively:
R1, R1′, R2, R2′=CR4, and R4=H, F, Cl, or CH 3 ; and
R6, R6′=Cl or CCH 3 .
provided that Z and the pyridine residue are not linked by a glycosidic bond.
In one embodiment, the compounds according to the invention contain adenine analogs such as C 8 -substituted and N 6 -substituted adenine, deaza variants such as 7-deaza, aza variants such as 8-aza or combinations such as 7-deaza or 8-aza or carbocyclic analogs such as formycin where the 7-deaza variants can be substituted in the 7 position with halogen, C 1 -C 6 alkinyl, C 1 -C 6 alkenyl or C 1 -C 6 alkyl.
In another embodiment, the compounds contain adenosine analogs which contain for example 2-methoxydeoxyribose, 2′-fluorodeoxyribose, hexitol, altritol or polycyclic analogues such as bicyclic, LNA and tricyclic sugars instead of ribose.
In particular, (di)phosphate oxygens can also be isoelectronically substituted such as for example O − by S − or BH 3 − , O by NH, NCH 3 or CH 2 and ═O by ═S.
Another preferred embodiment is a compound and a test element comprising the same having the general formula (III), or a salt or optionally a reduced form thereof:
in which
U=OH, SH, BH − 3 , or BCNH 2 − ; V=OH or a phosphate group; W=COOR, CON(R) 2 , COR, or CSN(R) 2 , where R=H or C 1 -C 2 alkyl; X=O, CH 2 , or NH; R1=C(R4) 2 , O, S, NCH 3 , NH, CH, CHOH, or CHOH 3 , wherein R4=H, F, Cl, or CH 3 ; and R4′=H or OH.
Biochemical tests for analytes, for example parameters in body fluids such as blood, serum, plasma or urine or in samples of waste water or of foods are of major importance in diagnostics. In these tests the analyte to be determined is brought into contact with a suitable enzyme and a coenzyme.
Hence, another subject matter of the present invention is an enzyme-coenzyme complex consisting of a compound according to the invention in combination with a suitable enzyme.
Any biological or chemical substances that can be detected by a redox reaction can be determined as analytes, e.g. substances which are substrates of a coenzyme-dependent enzyme or the coenzyme-dependent enzymes themselves. Examples of analytes are glucose, lactic acid, malic acid, glycerol, alcohol, cholesterol, triglycerides, ascorbic acid, cysteine, glutathione, peptides, urea, ammonia, salicylate, pyruvate, 5′-nucleotidase, creatine kinase (CK), lactate dehydrogenase (ILDH), carbon dioxide, etc.
For the detection of enzyme substrates, the test element can contain an enzyme that is suitable for detecting the substrate, in addition to the coenzyme. Suitable enzymes are for example dehydrogenases selected from glucose dehydrogenase (E.C. 1.1.1.47), lactate dehydrogenase (E.C. 1.1.1.27.1.1.1.28), malate dehydrogenase (E.C. 1.1.1.37), glycerol dehydrogenase (E.C. 1.1.1.6), alcohol dehydrogenase (E.C. 1.1.1.1), alpha-hydroxybutyrate dehydrogenase, sorbitol dehydrogenase or amino acid dehydrogenase e.g. L-amino acid dehydrogenase (E.C. 1.4.1.5). Further suitable enzymes are oxidases such as glucose oxidase (E.C. 1.1.3.4) or cholesterol oxidase (E.C. 1.1.3.6) or aminotransferases such as aspartate or alanine aminotransferase, 5′-nucleotidase or creatine kinase.
For the detection of enzymes, the test element can contain an enzyme substrate suitable for detecting the enzyme, in addition to the coenzyme.
Another subject matter of the present invention is the use of a compound according to the invention or of an enzyme-coenzyme complex according to the invention to detect an analyte in a sample by an enzymatic reaction. In this connection the detection of glucose with the aid of glucose dehydrogenase is particularly preferred.
The change in the coenzyme, i.e. in the compound according to the invention, by reaction with the analyte (if the analyte is an enzyme substrate) or by an analyte-catalysed reaction (if the analyte is an enzyme), can in principle be detected in any desired manner. Basically all methods for detecting enzymatic reactions that are known from the prior art can be used, for example optical methods and electrochemical methods. However, for purposes of illustrating the following description; the method to detect the change in the coenzyme is stated to be by optical methods. Examples of optical detection methods include the measurement of absorption, fluorescence, circular dichroism (CD), optical rotary dispersion (ORD), refractometry, etc. Fluorescence measurement, for example, is highly sensitive and enables the detection even of low concentrations of the analyte in miniaturized systems.
A liquid test can be used to detect an analyte in which the reagent is present, for example, in the form of a solution or suspension in an aqueous or non-aqueous liquid or it is present as a powder or lyophilisatc. It is, however, also possible to use a dry test, in which case the reagent is applied to a carrier. The carrier can, for example, be a test strip comprising an absorbent or/and swellable material that is wetted by the sample liquid to be examined.
A gel matrix in which an enzyme-coenzyme complex is incorporated can, however, also be used as a detection reagent (cf. DE 102 218 45 A1).
In this case, the enzyme can either be polymerized into the matrix together with the compound according to the invention or, after the polymerization, the matrix can be contacted with a solution of the coenzyme in the presence of the enzyme to form the corresponding enzyme-coenzyme complex.
Another subject matter of the present invention concerns a reagent matrix and its use to detect analytes. The reagent matrix can contain a compound according to the invention, a suitable enzyme and a suitable reaction buffer. Suitable enzymes have already been described. The reagent matrix according to the invention can be used in a wide variety of ways and can be used to determine analytes such as glucose, lactic acid, malic acid, glycerol, alcohol, cholesterol, triglycerides, ascorbic acid, cysteine, glutathione, peptides, urea, ammonia, salicylate, pyruvate, 5′-nucleotidase, CK, LDH, carbon dioxide, etc. A reagent matrix in one embodiment contains a compound according to the invention and glucose dehydrogenase (E.C. 1.1.1.47) to detect glucose in blood.
The reagent matrix according to the invention can be used to detect an analyte in a dry or liquid test.
Another subject matter of the present invention concerns a test strip for the fluorometric or photometric detection of an analyte. Such a test strip contains a compound as stated above as a coenzyme and optionally a suitable enzyme or an enzyme substrate immobilized on an absorbent or/and swellable material. Suitable materials can for example be selected from cellulose, plastics etc.
Another subject matter of the present invention comprises a method for detecting an analyte comprising the steps:
(a) contacting a sample with a test element or reagent matrix according to the invention comprising a coenzyme and (b) detecting the analytic e.g. on the basis of the change in the coenzyme.
Another aspect of the invention is that the fluorescence emission of the coenzymes exhibits a bathochromic shift such that there is less interference with the fluorescence emission of other materials of the test element or/and of the sample.
Embodiments of the subject matter of the present invention that are shown are also intended to apply to other subject matters of the invention such as, e.g. other embodiments of the compounds according to the invention.
These and other features and advantages of the present invention will be more fully understood from the following detailed description of the invention taken together with the accompanying claims. It is noted that the scope of the claims is definitely by the recitations therein and not by the specific discussion of the features and advantages set forth in the present description.
BRIEF DESCRIPTION OF THE DRAWINGS
The following detailed description of the embodiments of the present invention can be best understood when read in conjunction with the following drawings, where like structure is indicated with like reference numerals and in which:
FIG. 1 is a scheme for the preparation of hexitol nicotinamide adenine dinucleotide, lithium salt.
FIG. 2 is a scheme for the preparation of altritol nicotinamide adenine dinucleotide, lithium salt.
FIG. 3 is a scheme for the preparation of cyclohexene nicotinamide adenine nucleotide.
Skilled artisans appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figure may be exaggerated relative to other elements to help improve understanding of the embodiment(s) of the present invention.
In order that the invention may be more readily understood, reference is made to the following examples, which are intended to illustrate the invention, but not limit the scope thereof
DETAILED DESCRIPTION
The following descriptions of embodiments are merely exemplary in nature and are in no way intended to limit the invention or its application or uses.
The preparation of stable NAD/NADH derivatives for purposes of the present invention is shown on the basis of the synthesis schemes 1, 2 and 3 as examples ( FIGS. 1 , 2 and 3 ), described below.
All solvents were distilled before use and purified by standard methods. 1 H NMR was measured on a 200 MHz or 500 MHz Varian instrument using TMS as an internal standard for 1 H NMR and DMSOd 6 (39.6 ppm) as an internal standard for 13 C NMR. 31 P NMR spectra were measured using 85% H 3 PO 4 as an external standard. Mass spectroscopy: Q-T of 2, microscale with an ESI interface. TLC: coated aluminium strips (Fluka silica gel/TLC cards, 254 nm). Detection: UV and anisaldehyde sulphuric acid spray; column chromatography: silica gel (0.060-0.200 nm).
Synthesis Scheme 1
Referring now to FIG. 1 , an illustrative synthesis scheme is provided for preparation of hexitol nicotinamide adenine dinucleotide lithium salt 8 in a series of steps in which numbers refer to like-numbered molecular diagrams in FIG. 1 .
Step 1: Preparation of 1,5-Anhydro-4,6-O-benzylidene-3-deoxy-2-O-methane sulfonyl-D-ribohexitol 2
A spatula tip full of 4-dimethylaminopyridine in 40 ml absolute pyridine methane-sulfonylchloride (3 ml, 38 mmol) is added to a solution of 1,5-anhydro-4,6-O-benzylidene-3-deoxy-d-glucitol 1 (Andersen M. W. et al., Tetrahedron Lett., 1996, 37, 8147-8150) (5.000 g, 21.16 mmol) while cooling on ice and stirring. The mixture is stirred at room temperature for 14 h. After evaporation using a rotary evaporator, it is stirred in toluene and again evaporated. The residue is digested three times with warm CHCl 3 . The combined extracts are filtered over a short silica gel column. The solvent is removed on a rotary evaporator under vacuum. The residue is washed with ether and precipitated from methanol.
Yield 2: (5.103 g, 77%). R f 0.8 (hexane/EtOAc ½), 0.5 (hexane/EtOAc 2/1). 1 H NMR (200 MHz, CDCl 3 ) δ 1.92 (ddd, 2 J 3ax,3eq =12 Hz, 3 J 3ax,4 =11 Hz, 3 J 2,3ax =11.5 Hz, 1H, H-3ax), 2.68 (dm, 2 J 3ax,3eq =12 Hz, 3 J 2,3eq =5.5 Hz, 3 J 3eq,4 =4 Hz, 1H, H-3eq), 3.06 (s, 3H, CH 3 ), 3.32 (ddd, 3 J 5,6az =10 Hz, 3 J 4,5 =8 Hz, 3 J 5,6aq =5 Hz, 1H, H-5), 3.41 (t, 2 J 1ax,1eq = 3 J 1ax,2 =11 Hz, H-1ax), 3.59 (ddd, 3 J 3az,4 =11 Hz, 3 J 4,5 =8 Hz, 3 J 3eq,4 =4 Hz, 1H, H-4) 3.68 (t, 2 J 6ax,6eq = 3 J 5,6ax =10 Hz, 1H, H-6ax), 4.21 (ddd, 2 J 1ax,1eq =11 Hz, 3 J 1eq,2 =5.5 Hz, 4 J 1eq,3eq =2 Hz, 1H, H-1eq), 4.33 (dd, 2 J 6ax,6eq =10 Hz, 3 J 5,6eq =5 Hz, 1H, H-6eq), 4.81 (m, 3 J 2,3ax =11.5 Hz, 3 J 1ax,2 =11 hz, 3 J 1eq,2 = 3 J 2,3eq =5.5 Hz, 1H, H-2), 5.53 (s, 1H, PhCH), 7.33-7.51 ppm (m, 5H, aromatic H).
Step 2: Preparation of 1,5-Anhydro-2-azido-4,6-O-benzylidene-2,3-dideoxy-D-arabino-hexitol 3
Sodium azide (2.1 g, 32 mmol) is added to a solution of 2 (5.000 g, 15.91 mmol) in 120 ml N,N-dimethylformamide. The mixture is heated to 80° C. for 31 h under nitrogen while stirring. After cooling to room temperature, the solvent is removed by distillation under vacuum on a rotary evaporator. The residue is digested three times with warm CHCl 3 . The combined extracts are filtered over a short silica gel column. The solvent is removed on a rotary evaporator under vacuum. The residue is washed with ether and precipitated from hexane.
Yield 3 (4.073 g, 98%) colourless powder. R f 0.9 (hexane/EtOAc 2/1). 1 H NMR (200 MHz, CDCl 3 ) δ 1.91 (dd, 2 J 3ax,3eq =13 Hz, 3 J 3ax,4 =12 Hz, 3 J 2,3ax =4 Hz, 1H, H-3ax), 2.33 (dm, 2 J 3ax,3eq =13 Hz, 1H, H-3eq), 3.39 (ddd, 3 J 5,6ax 10 Hz, 3 J 5,6eq =5Hz, 1H, H-5), 3.69 (dd, 2 J 1ax,1eq =12 Hz, 3 J 1ax,2 =2 Hz, 1H, H-1ax), 3.77 (t, 2 J 6ax,6eq = 3 J 5,6ax =10 Hz, 1H, H-6ax), 3.55-4.06 (m, 3H, H-1 eq, H-2, H-4), 4.28 (dd, 2 J 6ax,6ex =10 Hz, 3 J 5,6eq =5 Hz, 1H, H-6 eq), 5.60 (s, 1H, PhCH), 7.34-7.52 ppm (m, 5H, aromatic H).
Step 3: Preparation of 1,5-Anhydro-2-azido-Z 3-dideoxy-D-arabino-hexitol 4
A solution of 3 (4.000 g, 15.31 mmol) in 180 ml 80% glacial acetic acid is stirred for 1 h at 95° C. After evaporation on a rotary evaporator it is stirred in water and again evaporated. Then it is stirred with toluene and again evaporated. The residue is purified by column chromatography (0-10% EtOAc in hexane). The solvent is removed from the combined product fractions by distillation on a rotary evaporator under vacuum. The residue is dried in a vacuum over P 2 O 5
Yield 4 (2.174 g, 82%) oil. R f 0.25 (hexane/EtOAc ½). 1 H NMR (200 MHz. CDCl 3 ) δ 1.72 (ddd, 2 J 3ax,3eq =14 Hz, 3 J 3ax,4 =11 Hz, 3 J 2,3ax =4 Hz, 1H, H-3ax), 2.33 (dm, 2 J 3ax,3ex =14 Hz, 1H, H-3 eq), 2.67 (br.s, 1H, OH), 3.05 (br.s, 1H, OH), 3.20 (dm, 3 J 4,5 =9 Hz, 1H, H-5), 3.59 (dd, 2 J 1ax,1eq =12 Hz, 3 J 1ax,2 =2 Hz, 1H, H-1ax), 3.74-4.04 (m, 5H, H-1 eq, H-2, H-4, H-6a, H-6b).
Step 4: Preparation of 1,5-Anhydro-2-azido-2,3-dideoxy-6-O-phosphono-D-arabino-hexitol ammonium salt 5
The azide 4 (1.004 g, 5.80 mmol) is dissolved by stirring in 6 ml trimethylphosphate (freshly vacuum distilled over BaO) under nitrogen. 1.7 ml of a 1/1 (v/v) mixture of phosphoryl chloride (freshly distilled) and trimethyl phosphate is added all at once at 0° C. After stirring for 3 h at 0° C., 6 ml ice water and 9 ml cold triethylamine are added. The mixture is evaporated to dryness on a rotary evaporator in a vacuum. The residue is washed with diisopropyl ether and purified by column chromatography [0-35% ammonium hydroxide (20% solution in water) in i-PrOH]. The solvent is removed from the combined product fractions by distillation under vacuum on a rotary evaporator.
Yield 5 (0.677 g, 43%) pale yellow oil. Rf 0.35 (i-PrOH/25% NH 4 OH aq /H 2 O 6/3/1). 1 H NMR (200 MHz, D 2 O) δ 1.80 (ddd, 2 J 3ax,3eq =13.5 Hz, 3 J 3ax,4 =11 Hz, 3 J 2,3ax =3.5 Hz, 1H, H-3ax), 2.34 (dm, 2 J 3ax,3eq =13.5 Hz, 1H, H-3eq), 3.43 (ddd, 3 J 4,4 =8.5 Hz, 3 J 5,6a =5.5 Hz, 3 J 5,6b =2Hz, 1H, H-5), 3.68 (dd, 2 J 1ax,1eq =12.5 Hz, 3 J 1ax,2 =1.5 Hz, 1H, H-1ax), 3.77-4.24 ppm (m, 5H, H-1 eq, H-2, H-4, H-6a, H-6b).
Step 5: Preparation of 2-Amino-1,5-anhydro-2,3-dideoxy-6-O-phosphono-D-arabino-hexitol sodium salt 6
25 ml methanol and Adam's catalyst (PtO 2 .H 2 O, 0.068 g, 0.28 mmol) are added to a solution of the azide 5 (0.677 g, 2.51 mmol) dissolved in 75 ml water. The mixture is shaken for 2 h in a Parr hydrogenation apparatus (30 psi). The catalyst is removed by filtration and the solvent is removed from the filtrate by distillation on a rotary evaporator under vacuum. The residue is dissolved in water and applied to a Dowex 50WX4-400 (Na + ) ion exchange column and eluted with water. The solvent is removed from the combined product fractions by distillation on a rotary evaporator under vacuum. The residue is dried in a vacuum over P 2 O 5 .
Yield 6 (0.666 g, 98%) pale yellow solidified oil. R f 0.2 (i-PrOH/25%-NH 4 OH aq /H 2 O 6/3/1). 1 H NMR (500 MHz, D 2 O) δ 1.93 (ddd, 2 J 3ax,3eq =14.4 Hz, 3 J 3ax,4 =12.1 Hz, 3 J 2,3ax =4.1 Hz, 1H, H-3ax), 2.34 (m, 2 J 3ax,3eq =14.4 Hz, 3 J 2,3eq =2.6 Hz. 3 J 3eq,4 =5.1 Hz, 4 J 1eq,3eq =2.6 Hz, 1H, H-3 eq), 3.41 (m, 3 J 4,5 =9.6 Hz, 3 J 5,6a =4.1 Hz, 3 J 5,6b =2.2 Hz, 4 J 5,P =0.5 Hz, 1H, H-5), 3.73 (m, 3 J 2,3ax =4.1 Hz, 3 J 2,3eq =2.6 Hz, 3 J 1ax,2 =2.0, 3 J 1eq,2 =1.7 Hz, 1H, H-2), 3.78 (dd, 2 J 1ax,1eq =13.2 Hz, 3 J 1ax,2 =2.0 Hz, 1H, H-1ax), 3.97 (ddd, 2 J 1ax,1eq =13.2 Hz, 3 J 1eq,2 =1.7 Hz, 4 J 1eq,3eq =2.6 Hz, 1-H, H-1 eq), 3.98 (ddd, 3 J 3ax,4 =12.1 Hz, 3 J 4,5 =9.6 Hz, 3 J 3eq,4 =5.1 Hz, 1H, H-4), 4.01 (ddd, 2 J 6a,6b =11.8 Hz. 3 J 5,6b =2.2 Hz, 3 J 6b,P =5.4 Hz, 1H, H-6b), 4.05 (ddd, 2 J 6a,6b =11.8 Hz, 3 J 5,6a =4.1 Hz ppm, 3 J 6aP =6.9, H-6a).
31 P NMR (202 MHz, D 2 O) δ 3.51 ppm.
Step 6: Preparation of 1,5-Anhydro-2-(3-carbamoylpyridinium)-2,3-dideoxy-6-O-phosphono-D-glucitol 7
First, 1-(2,4-Dinitrophenyl)-3-carbamoylpyridinium tetrafluoroborate 100 is prepared as follows: 58.6 g Dinitrochlorobenzene is melted under nitrogen and then 29.32 g nicotinamide is added to the melt. It is heated for 2.5 h at 110° C. 500 ml of a 3:2 (v/v) ethanol/water mixture is added through a reflux cooler and reflux boiled until a solution is formed. After stirring overnight at room temperature, 150 ml 50% ethanol/water and 100 ml water are added, transferred to a separating funnel and washed three times with 500 ml chloroform each time. 300 ml and 50 g active carbon is added to the separated aqueous phase which is stirred for 1 h at room temperature and then filtered over a Seitz K700 deep bed filter. The filtrate is concentrated on a rotary evaporator in a vacuum to about 100 ml during which the bath temperature must not exceed 20° C. It is diluted with 300 ml water and 70 g sodium tetrafluoroborate is added while stirring at room temperature. The precipitate is recrystallized from methanol/water. The crystallisate is filtered with a small amount of acetone and then washed with diethyl ether and dried for 24 h in a high vacuum at 40° C.
Yield 100 21.1 g (23%). TLC (Merck, silica gel 60 F-254: butanol/glacial acetic acid/water 5:2:3, R f =0.56.
Next, a solution of 100 (0.148 g, 0.46 mol) in 1.5 ml H 2 O is added dropwise during 5 h to a solution of 6 (0.100 g, 0.40 mmol) in 6 ml water and 4 ml methanol while stirring. It is stirred for 4 days at 40° C. During this time 0.3 ml of a 0.5 M aqueous triethylammonium bicarbonate (TEAB) solution is added. The course of the reaction is monitored using TLC. As soon as no more starting amine is seen, TEAB is added and it is cooled to 0° C. The precipitate is separated by centrifugation. The solvent is removed from the supernatant by distillation on a rotary evaporator. It is prepurified by column chromatography on DEAE Whatman DE-52 cellulose (21 mm×14 cm) using 0.01 M TEAB as the eluant. The main purification is by HPLC on DEAE Sephadex A-25 cellulose (18 mm×24 cm), equilibrated with 0.01 M TEAB and it is eluted with a TEAB solution of increasing concentration (0.01→0.5 M). The solvent is removed from the combined product fractions by vacuum distillation on a rotary evaporator. The residue is dissolved in 100 ml water and lyophilized. This procedure is repeated three times.
Yield 7 (0.083 g, 59%) yellow solidified oil. R f 0.15 (i-PrOH/25%-NH 4 OH aq /H 2 O 6/4/1). +ESI MS: m/z 333.1 [M + ]; −ESI MS: 331.4 [M + −2H] − , 1 H NMR (200 MHz, D 2 O) δ 2.40 (ddd, 2 J 3′ax,3′eq =15 Hz, 3 J 3′ax,4′ =12 Hz, 3 J 2′,3′ax =5 Hz, 1H, H-3′ax), 2.66 (dm, 2 J 3′ax,3′eq =15 Hz, 3 J 3′eq,4′ =5 Hz, 1H, H-3′eq), 3.66 (dm, 3 J 4′,5′ =9 Hz, 1H, H-5′), 3.95 (ddd, 3 J 3′ax,4′ =12 Hz, 3 J 4′,5′ =9 Hz, 3 J 3′eq,4′ =5 Hz, 1H, H-4′), 4.16 (m, 2H, H-6′), 4.26 (dd, 2 J 1′ax,1′eq =14 Hz, 3 J 1′ax,2′ =3 Hz, 1H, H-1′ax), 4.63 (br.d, 2 J 1′ax,1′eq =14 Hz, 1H, H-1′eq), 5.26 (br, 1H, H-2′), 8.27 (dd, 3 J 4,5 =8 Hz, 3 J 5,6 =6 Hz, 1H, H-5), 8.94 (d, 3 J 4,5 =8 Hz, 1H, H-4), 9.39 (d, 3 J 5,6 =6 Hz, 1H, H-6), 9.49 ppm (s, 1H, H-2).
Step 7: Preparation of Hexitolnicolinamide adenine dinucleotide lithium salt 8
First, adenosine-5′-(phosphorus-di-n-butylphosphinothio-anhydride) 200 is synthesized according to the relevant literature (Slama, J. T., Radziejewski, C., Oruganti, S., Kaiser, E. T., J. Am. Chem. Soc . (1984), 106, 6778-6785): R f 0.9 (i-PrOH/25%-NH 4 OH aq /H 2 O 6/3/1): 1 H NMR (500 MHz, D 2 O) δ 0.78 (m, 6H, CH 3 ), 1.27 (m, 4H, CH 2 (Bu)), 1.46 (m, 4H, CH 2 (Bu)), 2.04 (m, 4H, CH 2 (Bu)), 4.17 (dm, 1H), 4.37 (ddd, 1H), 4.54 (dd, J=5 ml Hz, J=3.7 Hz, 1H), 4.83 (dd, 1H), 6.12 (d, J=5.9 Hz, 1H, H-1′), 8.24 (s, 1H, H-2), 8.46 ppm (s, 1H, H-8). 13 C NMR (125 MHz, D 2 O) δ 12.91 (CH 3 ), 12.94 (CH 3 ), 23.0 (MeCH 2 ), 24.2 (EtCH 2 ), 33.76 (d, 1 J cp =68.4 Hz, CP), 33.83 (d, 1 J cp =68.4 Hz, CP), 65.68 (d, 2 J cp =5.8 Hz, C-5′), 70.68 (C-3′), 74.13 (C-2′), 83.91 (d, 3 J cp =9.8 Hz, C-4′), 87.15 (C-1′), 118.84 (C-5), 140.06 (C-8), 149.41 (C-4), 155.86 (C-2), 160.44 ppm (C-6).
31 P NMR (202 M Hz, D 2 O) δ−9.17 (d, 2 J PP =34.2 Hz, P═O), 103.9 (d, 2 J PP =34.2 Hz, P═S).
Accordingly, di-n-butylphosphiinothioyl bromide and tetra-n-butyldiphospine disulfide are synthesized according to the relevant literature (Furusawa, K., Sekine, M., Hata, T., J. Chem. Soc., Perkin Trans I (1976), 1711-1716; Kuchen, W., Buchwald, H., Strolenberg, K., Metten, J., Ann (1962), 652, 28-35).
Next, the nucleotide 7 (0.067 g, 0.2 mol) and 200 (0.211 g, 0.4 mol) are stirred under argon in a mixture of 1 ml dry amine-free DMF and 3 ml pyridine (freshly distilled over BaO). The solvents are removed by distillation in a vacuum. The dissolving and distillation procedure is repeated three times. The residue is then dissolved in a mixture of 2.4 ml absolute DMF and 3 ml absolute pyridine. Silver nitrate (0.274 g, 1.61 mmol) is added all at once in the absence of light and under argon. 15 ml water is added after 40 h stirring at room temperature and H 2 S is briefly passed in. The silver sulfide precipitate is removed by filtration over celite. The filtrate is washed three times with 5 ml chloroform each time. The solvent is removed from the aqueous phase extract by vacuum distillation on a rotary evaporator. The product is purified by three chromatographies.
1) DEAE Sephadex A-25 cellulose (18 mm×24 cm), equilibrated with 0.01 M TEAB, elution with TEAB solution (0.01→0.5 M). The solvent is removed from the combined product fractions by vacuum distillation on a rotary evaporator. The residue is dissolved in 100 ml water and lyophilized. This procedure is repeated three times.
2) DEAE Whatman DE-52 cellulose (18 mm×25 cm) preequilibrated with water, elution with aqueous formic acid (0→0.3 M). The solvent is removed from the combined product fractions by vacuum distillation on a rotary evaporator. The residue is dissolved in 100 ml water and lyophilized. This procedure is repeated twice. The solution is adjusted to pH 6 with 0.1 M LiOH.
3) Sephadex LH-20 cellulose (18 mm×31 cm) with water as the eluant. The solvent is removed from the combined product fractions by vacuum distillation on a rotary evaporator. The residue is dissolved in 100 ml water and lyophilized. This procedure is repeated twice.
Yield 8 (0.026 g, 19%) colourless powder. R f 0.5 (i-PrOH/25%-NH 4 OH aq /H 2 O 6/4/1). Exact theoretical mass for C 22 H 28 N 7 O 13 P 2 [M + −2H] 660.1220. found 660.1229 UV(H 2 O): λ max 259 nm. 1 NMR (500 MHz, D 2 O) δ 2.37 (ddd, 2 J 3′ax,3′eq =15.0 Hz, 3 J 3′ax,4′ 11.5 Hz, 3 J 2′,3′ax =5.2 Hz, 1H, NH-3′ax), 2.62 (m, 2 J 3′ax,3′eq =15.0 Hz, 3 J 2′,3′eq =2.8 Hz, 2 J 3′eq,4′ =4.8 Hz, 4 J 1′eq,3′eq =2.8 Hz, 1H, NH-3′eq), 3.66 (m, 3 J 4′,5′ =9.2 Hz, 3 J 5′,6′a =3.1 Hz, 3 J 5′,6′b =3.1 Hz, 1H. NH-5′), 3.95 (ddd, 3 J 3′ax,4′ =11.5 Hz, 3 J 4′,5′ =9.2 Hz, 3 J 3′eq,4′ =4.8 Hz, 1H, NH-4′), 4.22 (dd, 2 J 1′ax,1′eq =14.4 Hz, 3 J 1′ax,2′ =3.1 Hz, 1H, NH-1′ax), 4.24 (m, 2 J 5′a,5′b′ =12.1 Hz, 3 J 4′,5′a =3.1 Hz, 1H, AH-5′a), 4.27 (m 3 J 5′,6′ =3.1 Hz, 2H, NH-6′), 4.28 (m, 2 J 5′a,5′b =12.1 Hz, 3 J 4′,5′b =3.1 Hz, 1H, AH 5′b), 4.40 (m, 3 J 3′,4′ =3.1 Hz, 3 J 4′,5′a =3.1 Hz, 3 J 4′,5′b =3.1 Hz, 4 J 4′P =1.9 Hz, 1H, AH-4′), 4.53 (dd, 3 J 2′,3′ =4.7 Hz, 2 J 3′,4′ =3.1 Hz, 1H, AH-3′), 4.57 (ddd, 2 J 1′ax,1′eq =14.4 Hz, 3 J 1′eq,2′ =2.6 Hz, 4 J 1′eq,3′eq =2.8 Hz, 1H, NH-1″eq), 4.74 (t, 3 J 1′,2′ =3.1 Hz, 3 J 2′,3′ =3.1 Hz, 1H, AH-2′), 5.20 (m, 3 J 2′,3′ =5.1 Hz, 3 J 2′,3′eq =2.8 Hz, 3 J 1′ax,2′ =3.1 Hz, 3 J 1′eq,2′ =2.6 Hz, 1H, NH-2′), 6.14 (d, 3 J 1′,2′ =5.4 Hz, 1H, AH-1′), 8.25 (dd, 3 J 4,5 =8.3 Hz, 3 J 5,6 =6.1 Hz, 1H, NH-5), 8.40 (s, 1H, AH-2), 8.60 (s, 1H, AH-8) 8.89 (dd, 3 J 4,5 =8.3 Hz, 4 J 2,4 =1.5 Hz, 1H, NH-4), 9.37 (d, 3 J 5,6 =6.1 Hz, 4 J 2,6 =1.5 Hz, 1H, NH-6), 9.45 ppm (t, 4 J 2,4 =1.5 Hz, 4 J 2,6 =1.5 Hz, 1H, NH-2).
13 C NMR (125 MHz, D 2 O) δ 38.39 (NC-3′), 62.59 (NC-4′), 67.45 (dd, 2 J 6′P =4.9 Hz, 4 J 6′P =2.8 Hz, NC-6′), 67.86 (dd, 2 J 5′P =3.7 Hz, 4 J 5′P =2.8 Hz, AC-5′), 69.59 (NC-2′), 69.78 (NC-1′), 73.02 (AC-3′), 77.37 (AC-2′), 83.22 (d, 3 J 5′P =7.9 Hz, NC-5′), 86.89 (d, 3 J 4′P =8.7 Hz, AC-4′), 90.49 (AC-1′), 121.20 (AC-5), 131.48 (NC-5), 136.76 (NC-3) 144.73 (AC-8), 146.72 (NC-2), 147.04 (NC-4), 148.73 (NC-6), 149.22 (AC-4), 151.15 (AC-2), 153.44 (AC-6), 168.50 ppm (CONH 2 ).
31 P NMR (202 MHz, D 2 O) δ-10.70 (d, 2 J PP =20.5 Hz, 1P, AP), −10.31 ppm (d, 2 J PP =20.5 Hz, 1P, NP).
Synthesis Scheme 2
Referring now to FIG. 2 , an illustrative synthesis scheme is provided for preparation of altritolnicotinamine adenine dinucleotide lithium salt 15 in a series of steps in which numbers refer to like-numbered molecular diagrams in FIG. 2 .
Step 1: Preparation of 1,5-anhydro-2-azido-4,6-O-benzylidene-2-deoxy-D-altritol 10
Sodium azide (1.500 g, 23.07 mmol) and ammonium chloride (1.500 g, 28.04 mmol) are added to a solution of 1,5:2,3-anhydro-4,6-O-benzylidene-D-allitol 9 (Allart B. et al, Tetrahedron, 1999, 55, 6527-6546) (1.000 g, 4.27 mmol) in a mixture of 2-methoxyethanol and water 5:1 (240 ml). The mixture is stirred for 18 h under nitrogen at 100° C. After cooling to room temperature the solvent is removed by vacuum distillation on a rotary evaporator. The residue is digested three times with 100 ml warm CHCl 3 and then with CH 2 Cl 2 (100 ml). The combined extracts are filtered over a short silica gel column. The solvent is removed by vacuum distillation on a rotary evaporator.
Yield 10 (1.126 g, 95%) pale yellow oil. R f 0.7 (CH 2 Cl 2 /MeO 98/2). +ES1 MS: m/z 278.0 [M+H] + , m/z 300.0 [M+Na] + . 1 H NMR (200 MHz, CDCl 3 ) δ 2.46 (d, 3 J=1.5 Hz, 1H, OH), 3.68-3.94 (m, 5H), 4.05 (dd, J=13 Hz, J=2 Hz, 1H), 4.13 (br.s, 1H), 4.32 (m, 1H), 5.65 (s, 1H, PhCH), 7.35-7.55 ppm (m, 5H, aromatic H).
Step 2: Preparation of 1,5-anhydro-2-azido-2-deoxy-D-altritol 11
A solution of 10 (1.116 g, 4.02 mmol) in 180 ml 80% glacial acetic acid is stirred for 2 h at 95° C. It is stirred in water after evaporation on a rotary evaporator and again evaporated. It is then stirred with toluene and again evaporated. The residue is purified by column chromatography (30-90% EtOAc in hexane). The solvent is removed from the combined product fractions by vacuum distillation on a rotary evaporator. The residue is washed with CHCl 3 and dried in a vacuum over P 2 O 5 .
Yield 11 0.505 g (66%), R f 0.1 (hexane/EtOAc 1:2) 1 H NMR (500 MHz, DMSO-d 6 ) δ 3.38-3.45 (m, 3H, H-4, H-5, H-6a), 3.62 (overl, m, 1H, H-6b), 3.64 (overl, m, Δv 1/2 =6 Hz, 1H eq, H-2), 3.656 (d, 2 J 1ax,1eq =12.2 Hz, 1H, H-1ax), 3.722 (brs, Δv 1/2 =10 Hz, 1H eq , H-3), 3.748 (dd, 2 J 1eq,1ax =12.2 Hz, 3 J 1eq,2 =1.5 Hz, 1H. H-1 eq), 4.457 (brt, 1H, 6-OH), 4.690 (d, J 4,OH =4.6 Hz, 1H, 4-OH), 5.214 ppm (d, J 3,OH =4.1 Hz, 1H, 3-OH). 13 C NMR (125 MHz, DMSO-d 6 ), δ 61.15 (CH, C-2), 61.45 (CH 2 , C-6), 63.05 (CH 2 , C-1), 65.8 (CH, C-4), 68.21 (CH, C-3), 77.21 ppm (CH, C-5).
Step 3: Preparation of 1,5-anhydro-2-azido-2-deoxy-6-O-phosphono-D-altritol diammonium salt 12
Phosphate 12 is prepared similarly to phosphate 5 starting from azide 11 (0.503 g. 2.66 mmol). Coarse purification by column chromatography and silica gel (0.35% ammonia (20% aqueous solution in i-PrOH) pale yellow oil 12 (0.353 g, 46%). R f 0.4 (i-PrOH/25%-NH 4 OH aq /H 2 O 6/4/1). This product is used without further purification.
Step 4: Preparation of 1,5-anhydro-2-amino-2-deoxy-6-O-phosphono-D-altritol disodium salt 13
25 ml methanol and Adam's catalyst (PtO 2 .H 2 O, 0.068 g, 0.28 mmol) are added to a solution of the azide 12 (0.353 g, 1.31 mmol) dissolved in 15 ml water. The mixture is shaken for 85 h in a Parr hydrogenation apparatus (30 psi). The catalyst is removed by filtration and the solvent is removed from the filtrate by distillation on a rotary evaporator under vacuum. The residue is dissolved in water and applied to a Dowex 50WX4-400 (Na + ) ion exchange column and eluted with water. The solvent is removed from the combined product fractions by distillation on a rotary evaporator under vacuum. The residue is dried in a vacuum over P 2 O 5 .
Yield 13 (0.342 g, 91%) pale yellow amorphous powder. R f 0.25 (i-PrOH/25%-NH 4 OH aq /H 2 O 6/4/1). 1 H NMR (500 MHz, D 2 O) δ 3.489 (m, 1H, H-2), 3.725 (dt, 3 J 5,4 =9.1 Hz, 3 J 5,6a = 3 J 5,6b =3.4 Hz, 1H, H-5), 3.821 (d, 2 J 1ax,1eq =13.2 Hz, 1H, H-1ax), 3.863 (dd, 3 J 4,5 =9.1 Hz, 3 J 4,3 =3.2 Hz, 1H, H-4), 3.938 (dd, J 6,5 =3.4 Hz. J 6,P =6.0 Hz, 2H, H-6), 3.967 (dd, 2 J 1eq,1ax =13.2 Hz, 3 J 1eq,2 =1.7 Hz, 1H, H-1 eq), 4.197 ppm (t, 3 J 3,2 = 3 J 3,4 =3.2 Hz, 1H, H-3). 13 C NMR (125 MHz, D 2 O) δ54.02 (CH, C-2), 65.49 (CH 2 , C-6), 66.05 (CH 2 , C-1), 66.11 (CH, C-4), 69.07 (CH, C-3), 78.69 ppm (d, 3 J 5,P =7.31z, CH, C-5). 31 P NMR (202 MHz, D 2 O) δ 3.921 ppm.
Step 5: Preparation of 1,5-anhydro-2-(3-carbamoylpyridinium)-2-deoxy-6-O-phosphono-D-altritol 14
This is prepared in 42% yield similarly to preparation of 7 in Synthesis Scheme 1, by starting from the amine 13 (0.100 g, 0.35 mmol, solution in 4 ml MeOH and 5 ml water), Zincke Cl salt 100 (0.201 g, 0.62 mmol, solution in 2.1 in H 2 O) and 0.6 ml aqueous 0.5 M TEAB solution.
R f 0.15 (i-PrOH/25%-NH 4 —OH aq /H 2 O 6/4/1). 1 H NMR (200 MHz, D 2 O) δ4.02-4.23 (m, 4H), 4.40 (dd, 2 J 1′ax,1eq =13 Hz, 3 J 1′ax,2′ =4 Hz, 1H, H-1′ax), 4.54 (dd, 2 J 1′ax,1′eq =13 Hz, 3 J 1′eq ,2′ =4 Hz, 1H, H-1′eq), 4.60 (dd, 3 J 2′,3′ =6.5 Hz, 3 J 3′,4′ =2 Hz, 1H, H-3′), 5.04 (dt, 3 J 1′ax,2′ =4 Hz, 3 J 1′eq,2′ =4 Hz, 3 J 2′,3′ =6.5 Hz, 1H, H-2′), 8.30 (dd, 3 J 4,5 =8 Hz, 3 J 5,6 =7 Hz, 1H, H-5), 8.99 (d, 3 J 4,5 =8 Hz, 1H, H-4), 9.37 (d, 3 J 5,6 =7 Hz, 1H, H-6), 9.51 ppm (s, 1H, H-2).
Step 6: Preparation of altritolnicotinamine adenine dinucleotide lithium salt 15
The nucleotide 14 (0.051, 0.15 mmol) is stirred under argon in a mixture of 2.5 ml dry formamide (pA grade) and 1 ml pyridine (freshly distilled over BaO). The solvents are removed in a vacuum by distillation. The dissolving/distillation procedure is repeated three times. Adenosine-5′-(phosphorus-di-n-butyl-phosphinothio-anhydride) (0.155 g, 0.30 mmol) is added and the mixture is coevaporated three times with absolute pyridine. The residue is then dissolved in 2.0 ml absolute pyridine. Silver nitrate (0.200 g, 1.18 mmol, dried for 2 h at 120° C.) is added all at once in the absence of light and under argon. 15 ml water is added after 65 h stirring at room temperature and then the subsequent procedure is as described for 8 using a solution of 200.
Yield lithium salt 15 (0.039 g, 39%) colourless powder, R f 0.4 (i-PrOH/25%-NH 4 OH aq /H 2 O 6/4/1). Theoretical mass for C 22 H 28 N 7 O 14 P 2 [M+−2H] 676.1169. found 676.1147. −ESI MS: m/z 676 [M + −2H] − , m/z 698 [M + −3H+Na] − ; +ESI MS: m/z 678 [M + ], m/z 700 [M + −H+Na]. UV(H 2 O): λ max 259 nm.
1 H NMR (500 MHz, D 2 O) δ 4.10 (m, 1H, NH-5′), 4.10 (m, 3 J 3,4 =5.8 Hz, 1H, NH-4′), 4.24 (m, 2 J 5′a,5′b =11.7 Hz, 3 J 4′,5′a =3.3 Hz, 1H, AH-5′a), 4.27 (m, 2 J 5′a,′b =11.7 Hz, 3 J 4,5b =2.6 Hz, 1H, AH-5′b), 4.29 (m, 2H, NH-6′), 4.36 (dd, 2 J 1′ax,1′eq =13.2 Hz, 3 J 1′ax,2′ =4.1 Hz, 1H, NH-1′ax), 4.41 (m, 3 J 3′,4′ =3.2 Hz, 3 J 4′,5a′ =3.3 Hz, 3 J 4′,5′b =2.6 Hz, 1H, AH-4′), 4.46 (dd, 2 J 1′ax,1′eq =13.2 Hz, 3 J 1′eq,2′ =4.6 Hz, 1H. NH-1′eq), 4.53 (dd, 3 J 3′,4′ =5.8 Hz, 3 J 2′,3′ =2.7 Hz, 1H, NH-3′), 4.53 (dd, 3 J 2′,3′ =5.1 Hz, 3 J 3′,4′ =3.2 Hz, 1H, AH-3′), 4.77 (dd, 3 J 1′,2′ =5.7 Hz, 3 J 2′,3′ =5.1 Hz, 1H, AH-2′), 5.02 (ddd, 3 J 1′ax,2′ =4.1 Hz, 3 J 1′eq,2′ =4.6 Hz, 3 J 2′,3′eq =2.7 Hz, 1H, NH-2′), 6.13 (d, 3 J 1′,2′ =5.7 Hz, 1H, AH-1′), 8.25 (dd, 3 J 4,5 =8.3 Hz, 3 J 5,6 =6.0 Hz, 1H, NH-5), 8.31 (s, 1H, AH-2), 8.53 (s, 1H, AH-8), 8.9 (dd, 3 J 4,5 =8.3 Hz, 4 J 2,4 =1.5 Hz, 1H, NH-4), 9.30 (dd, 4 J 5,6 =6.0 Hz, 4J 2,6 =1.5 Hz, 1H. NH-6), 9.44 (t, 4 J 2,4 =1.5 Hz, 4 J 2,6 =1.5 Hz, 1H, NH-2). 13 C NMR (125 M-1z, D 2 O) δ 66.40 (NC-1′), 67.66 (dd, 2 J 6′P =5.0 Hz, NC-6′), 67.86 (d, 2 J 5′,P =6.4 Hz, AC-5′), 68.00 (NC-4′), 72.12 (NC-3′), 73.08 (NC-2′), 73.17 (AC-3′), 77.07 (AC-2′), 79.41 (d, 3 J 5′P =6.9 Hz, NC-5′), 86.67 (d, 3 J 4′,P =7.5 Hz, AC-4′), 89.91 (AC-1′), 121.23 (AC-5), 131.63 (NC-5), 136.80 (NC-3), 144.26 (AC-8), 146.75 (NC-2), 147.71 (NC-4), 148.95 (NC-6), 151.16 (AC-4), 151.46 (AC-2), 153.35 (AC-6), 165.67 ppm (CONH 2 ). 31 P NMR (202 MHz, D 2 O) δ−10.68 ppm.
Synthesis Scheme 3
Referring now to FIG. 3 , an illustrative synthesis scheme is provided for preparation of cyclohexenylnicotinamide adenine dinucleotide triethylammonium salt 22 in a series of steps in which numbers refer to like-numbered molecular diagrams in FIG. 3 .
Step 1. Preparation of (1S,4R,5S)—N-(5-hydroxy-4-hydroxymethyl-5,7-O-benzylidene-2-cyclohexen-1-yl)phthalimide 17
A solution of DIAD (5.3 ml, 25.52 mmol) in absolute THF (50 ml) is added slowly under nitrogen to a suspension of triphenylphosphine (7 g, 26.68 mmol), 16)(Wang J. et al., J. Org. Chem. 2001, 66, 8478-8482; Gu P. et al., Tetrahedron, 2004, 60, 2111-2123), (4.2 g, 18.08 mmol) and phthalimide (4 g, 27.18 mmol) in dry THF (170 ml) while stirring at room temperature. After stirring for 1 h, it is rotary evaporated. The residue is purified by column chromatography (EtOAc/hexane 2/8). The solvent is removed from the combined product fractions by distillation on a rotary evaporator under vacuum:
Yield 17 5.23 g (80%) colourless solid. 1 H NMR (CDCl 3 , 500 MHz) δ 2.14-2.18 (1H, m, J 6,6′ =13.9 Hz, J 6,1 =4.1 Hz, H6), 2.26-2.32 (1H, m, H6′), 2.51 (1H, m, H4), 3.86 (1H, m, 2 J=11.1 Hz, H7), 4.35-4.38 (1H, dd, J=10.7 Hz, J=4.4 Hz, H7′), 4.44-4.49 (1H, m, H5), 5.11 (1H, m, H1), 5.65-5.7 (3H, m, H2, H3, CHΦ)), 7.34-7.3 (9H, H arom.)
C 22 H 19 NO 4 (361): ESI: 362 (M+H) + , 384 (M+Na) + .
Step 2: Preparation of (1S,4R,5S)—N-(5-hydroxy-4-hydroxymethyl-2-cyclohexen-1)yl) phthalimide 18
A suspension of 17 (1.116 g, 4.02 mmol) in 80 ml 80% glacial acetic acid is stirred at 95° C. until a clear solution is formed. After evaporation on a rotary evaporator it is stirred in water and again evaporated. Then it is stirred with toluene and again evaporated. The residue is purified by column chromatography (EtOAc/hexane from 1/1 to 7/3). The solvent is removed from the combined product fractions by distillation under vacuum on a rotary evaporator.
Yield 18 3.4 g (90%). 1 H-NMR (DMSO-d6, 500 MHz) δ 1.76 (1H, m, H4), 2.16 (2, m, H6), 3.41 (2H, m, H7+H7′), 4.04 (1H, m, H-5), 4.69 (1H, 7-OH), 4.76 (1H, d, J=3.5 Hz, 3-OH), 4.94 (1H, m, H1), 5.63 (1H, m, H3), 5.67 (1H, m, H2), 7.83 (4H, Hpht.) C 15 H 15 NO 4 (273): ESI: 274 (M+H) + , 296 (M+Na) + .
Step 3: Preparation of (1S,4R,5S)-1-amino-4-O-phosphonomethyl-5-hydroxy-2-cyclohexene ammonium salt 20
Phosphorusoxy chloride (436 μl) is added to trimethyl phosphate (5.5 ml) while stirring under argon at 0° C. After stirring for 15 min at 0° C., 18 (600 mg, 2.19 mmol) is added all at once. After stirring for 3 h, 50 ml cold water is added and it is neutralized dropwise with triethylamine. The mixture is evaporated to dryness under vacuum on a rotary evaporator. The residue is washed with diisopropyl ether and purified by column chromatography on silica gel using iPrOH/NH 4 OH/H 2 O (6/3/1) as the eluant. The solvent is removed from the combined product fractions by distillation under vacuum on a rotary evaporator.
Yield 19 as a colourless solid (475 mg, 56%).
19 (300 mg, 0.775 mmol) is dissolved in 15 ml EtOH/H 2 O (1/1) and admixed with hydrazine monohydrate (75 μl, 1.55 mmol). Alter stirring overnight at 90° C., the solvents are removed by distillation under vacuum on a rotary evaporator. The residue is dissolved in water and washed with ethyl acetate. The solvent is removed from the aqueous phase by distillation under vacuum on a rotary evaporator. The residue is washed with diisopropyl ether and purified by column chromatography on silica gel using iPrOH/NH 4 OH/H 2 O (6/3/1) as the eluant. The solvent is removed from the combined product fractions by distillation under vacuum on a rotary evaporator.
Yield 20 (111 mg, 56%). 1 H-NMR (D 2 O, 500 MHz) δ 2.026 (ddd, J 6,6′ =13.9 Hz, J 6,5 =6.6 Hz, J 6,1 =3.2 Hz, 1H, H6), 2.50 (ddd, J 6,6′ =13.9 Hz, J 6′5 =8.1 Hz, J 6′1 =5.8 Hz, 1H, H6′), 2.43 (m, 1H, H4), 3.863 (dt, J 7,7′ =10.2 Hz, J 7,5 =J 7,P =5.6 Hz, 1H, H7), 3.976 (dt, J 7,7′ =10.2 Hz, J 7′,5′ =J 7′P =5.1 Hz, 1H, H7′), 4.032 (ma, 1H, H1), 4.148 (ddd, J 5,6′ =8.2 Hz, J 5,4 =5.1 Hz, J 5,6 =3.3 Hz, 1H, H5). 5.855 (dt, J 3,2 =10.2 Hz, J 3,4 =J 3,1 =2.5 Hz, 1H, H3), 6.004 ppm (dm, J 2,3 =10.2 Hz, 1H, H2). 31 P-NMR (D 2 O, 202 MHz) δ 1.95 ppm(s). Exact theoretical mass C 7 H 13 NO 5 P: 222.1477. found 222.0523.
Step 4: Preparation of (1S,4R,5S)-1-(carbamoylpyridine)-4-phosphonomethyl-5-hydroxy-2-cyclohexene triethylammonium salt 21
20 (0.07 g, 0.26 mmol) is stirred for 30 min at room temperature under nitrogen in a mixture of MeOH (4.5 ml) and dry Hünig base iPr 2 EtN (0.09 ml, 0.52 mmol). The Zincke BF4 salt (0.1 g, 0.28 mmol) is added all at once. The deep-red mixture is stirred for 5 h at 55° C. and an additional 0.03 g Zincke tetrafluoroborate salt is added and heated for a further 20 h. 50 ml of a TEAB (1 M) solution is added and evaporated to dryness on a rotary evaporator under vacuum. The crude product is purified by MPLC on DEAE cellulose. Firstly undesired by-products are eluted with water. Then the elution is continued with a gradient of 0.01 M TEAB to 0.5 M TEAB at a flow rate of 1 ml/min. The solvent is removed from the combined product fractions by distillation under a vacuum on a rotary evaporator.
Yield 21 0.09 g (92%): colourless amorphous powder. 1 H-NMR (D 2 O, 500 MHz) δ 2.31-2.35 (ddd, J 6′6″ =13.8 Hz J 6′,5′ =6.6 Hz, J 6,1′=3.1 Hz, 1H, H6′), 2.48-2.54 (dm, J 6,6′ =13.8 Hz, 1H, H6″), 2.59 (m, 1H, H4′), 4.05-4.11 (m, 3H, H7′, H7″, H5′), 5.67 (m, 1H, H1′), 6.05 (m, 1H, H3′), 6.41 (dm, J 2,3 =11.5 Hz, 1H, H2′), 8.22 (dd, J 5,4 =8 Hz, J 5,6 =6 Hz, 1H, H5), 8.92 (d J 4,5 =8 Hz, 1H, H4), 9.12 (d, J 6,5 =6.1 Hz, 1H, H6), 9.35 (s, 1H, H2). 31 P-NMR (D 2 O, 202 MHz) δ 1.02 ppm(s). Exact theoretical mass C 13 H 16 N 2 O 6 P: 327.2514. found 327.0739.
Step 5. Preparation of cyclohexenylnicotinamide adenine dinucleotide triethylammonium salt 22
9 ml of a 1:1 mixture of DMF/pyridine is added to the mononucleotide 21 (0.095 g, 0.178 mmol) and 200 (0.186 g, 0.356 mmol). The solvent is removed by distillation in a vacuum and it is taken up again in 9 ml of a 1:1 mixture of DMF/pyridine. This procedure is repeated once again. The residue is then thoroughly dried in a high vacuum and then again taken up in 9 ml of a 1:1 mixture of DMF/pyridine. Silver nitrate (0.242 g, 1.424 mmol) is added all at once in the absence of light and under argon. After 15 h stirring at room temperature 30 ml water is added and H 2 S is briefly passed in. The silver sulfide precipitate is removed by filtration over celite. The filtrate is washed three times with 5 ml chloroform each time. The solvent is removed from the aqueous phase by distillation under vacuum on a rotary evaporator. The crude product is purified by MPLC on DEAE cellulose. Firstly undesired by-products are eluted with water. Then the elution is continued with a gradient of 0.01 M TEAB to 0.25 M TEAB at a flow rate of 1 ml/min. The solvent is removed from the combined product fractions by distillation under vacuum on a rotary evaporator.
Yield 22 0.018 g (12%) colourless powder. 1 H-NMR (D 2 O 500 MHz) δ 2.23 (1H, ddd, J NH6′-NH6″ =14 Hz, J NH6′-NH5′ =8.3 Hz, J NH6′-NH1′ =6 Hz, NH6′), 2.39 (1H, ddd, J NH6′-NH6″ =14.2 Hz, J NH6″-NH1′ =6.2 Hz, J NH6″-NH5′ =3.1 Hz, NH6″), 2.48 (1H, m, J NH5′-NH4′ =5.5 Hz, J NH4′-NH7′ =4.5 Hz, J NH4′-NH3′ =3.1 Hz, J NH4′-NH2′ =2.8 Hz. NH4′), 4.04 (1H, ddd, J NH5′-NH6′ =8.3 Hz, J NH5′-NH4′ =5.5 Hz, J NH5′-NH6″ =3.1 Hz, NH5′), 4.09-4.14 (2H, dAB, J NH7′-NH7″ =10.6 Hz, J NH7′-NH4′ =4.5 Hz, J NH7″-NH4′ =3.8 Hz NH7′-NH7″), 4.20-4.23 (2H, dAB, J AH5′-AH5″ =11.9 Hz, J AH5′-AH4′ =3.1 Hz, J AH5″-AH4′ =3.5 Hz, AH5′-AH5″), 4.37 (1H, m, J AH4′-AH3′ =3.2 Hz, J AH4′-AH5′ =3.1 Hz. J AH4′-AH5′ =3.5 Hz, AH4′), 4.50 (1H, dd, J AH3′-AH2′ =5.6 Hz, J AH3′-AH4′ =3.2 Hz, AH3′), 4.75 (1H, dd, J AH2′-AH1′ =5.9 Hz, J AH2′-AH3′ =5.6 Hz, AH2′), 5.57 (1H, m, J NH1′-NH6″ =6.2 Hz, J NH1′-NH6′ =6.0 Hz, J NH1′-NH2′ =2.8 Hz, J NH1′-NH3′ =1.6 Hz, NH1′), 5.90 (1H, m, J NH2′-NH3′ =10.2 Hz, J NH2′-NH4′ =2.8 Hz, J NH2′-NH1′ =2.8 Hz, NH2′), 6.06 (1H, d, J AH1′-AH2′ =5.9 Hz, AH1′), 6.28 (1H, m, J NH3′-NH2′ =10.2Hz, J NH3′-NH4′ =3.1 Hz, J NH3′-NH1′ =1.6 Hz, NH3′), 8.15 (1H, dd, J NH5-NH4 =8.1 Hz, J NH5-NH6 =6.2 Hz, NH5), 8.19 (1H, S, AH8), 8.45 (1H, S, AH2), 8.80 (1H, d, J HN4-NH5 =8.1 Hz, NH4), 9.00 (1H, d, J NH6-NH5 =6.2 Hz, NH6), 9.27 ppm (1H, m, J NH2-NH4 =1.5 Hz, J NH2-NH6 =1.5 Hz, NH2).
13 C-NMR (D 2 O, 125 MHz) δ 38.53 (NC6′), 46.10 (NC4′, d, J NC4′-NP =8.8 Hz), 66.00 (NC5′), 68.01 (NC7′, d, J NH7′-NP =5.8 Hz), 68.18 (AC5′, d, J AC5′-AP =4.8 Hz), 69.88 (NC1′), 73.07 (AC3′), 76.75 (AC2′), 86.61 (AC4′, d, J AC4′-AP =8.7 Hz), 89.50 (AC1′), 121.16 (AC5), 125.08 (NC2′), 131.26 (NC5), 136.53 (NC3), 139.57 (NC3′), 142.54 (AC8), 145.98 (NC2), 147.12 NC4), 148.04 (NC6), 155.45 (AC2), 158.04 (AC4), 158.08 (AC6), 168.13 ppm (CONH 2 ).
31 P-NMR (D 2 O. 202 MHz) δ−10.88 (1P, d, J NP-AP =20.4 Hz, NP), −10.57 ppm (1P, d, J NP-AP =20.4 Hz, AP)
Theoretical mass C 23 H 29 N 7 O 12 P 2 : 657.471. found: 657.1313
It is noted that terms like “preferably”, “commonly”, and “typically” are not utilized herein to limit the scope of the claimed invention or to imply that certain features are critical, essential, or even important to the structure or function of the claimed invention. Rather, these terms are merely intended to highlight alternative or additional features that may or may not be utilized in a particular embodiment of the present invention.
For the purposes of describing and defining the present invention it is noted that the term “substantially” is utilized herein to represent the inherent degree of uncertainty that may be attributed to any quantitative comparison, value, measurement, or other representation. The term “substantially” is also utilized herein to represent the degree by which a quantitative representation may vary from a stated reference without resulting in a change in the basic function of the subject matter at issue.
Having described the invention in detail and by reference to specific embodiments thereof, it will be apparent that modification and variations are possible without departing from the scope of the invention defined in the appended claims. More specifically, although some aspects of the present invention are identified herein as preferred or particularly advantageous, it is contemplated that the present invention is not necessarily limited to these preferred aspects of the invention.
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The invention concerns stable nicotinamide adenine dinucleotide (NAD/NADH) and nicotinamide adenine dinucleotide phosphate (NADP/NADPH) derivatives, enzyme complexes of these derivatives and their use in biochemical detection methods and reagent matrices.
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This application claims priority from a Provisional Application, Ser. No. 60/470,711, filed May 15, 2003.
FIELD OF THE INVENTION
The present invention relates to medical equipment, and, more particularly, to machines for powering pneumatic ventricular assist devices.
BACKGROUND
Ventricular assist devices (“VAD”) are used to help supplement the heart's pumping action both during and after certain kinds of surgery, in situations where a complete cardiopulmonary bypass (using a heart-lung machine) is neither needed nor advisable in light of the serious side effects associated therewith. Ventricular assist devices typically comprise a pair of cannulae or other tubing and some sort of pump operably connected to the cannulae. In use, the cannulae are attached to either the left side of the heart (a left ventricular assist device) or to the right side of the heart (a right ventricular assist device) “in parallel,” i.e., the pump supplements the heart's pumping action but does not completely bypass it, and the pump is activated. Alternatively, a pump may be directly implanted into the body.
Originally, ventricular assist devices were air powered, wherein fluctuating air pressure, provided by a simple mechanical air pump machine, was applied to a bladder-like sac. The bladder had input and output valves, so that blood would enter the bladder through the input valve when the pressure on the bladder was low, and exit the bladder through the output valve when the pressure on the bladder was high. Unfortunately, these pneumatic ventricular assist devices were complicated, and used expensive mechanical valves that were prone to failure, subject to “clogging,” and that caused blood trauma or damage because of hard, metal edges and the like.
To overcome these problems, smaller, more reliable ventricular assist devices have been in use and/or development. These include axial flow pumps for temporary insertion directly into the heart, and peristaltic or centrifugal pumps. The former are based on the Archymides' Principle, where a rod with helical blades is rotated inside a tube to displace liquid. In use, a catheter-mounted, miniature axial flow pump is appropriately positioned inside the heart, and is caused to operate via some sort of external magnetic drive or other appropriate mechanism. With high enough RPM's, a significant amount of blood can be pumped. In the case of peristaltic pumps, blood is moved by the action of a rapidly rotating impeller (spinning cone or the like), which causes the blood to accelerate out an exit. Both of these categories of ventricular assist devices are generally reliable and implantable, but are very expensive, not particularly durable, and are not useful in situations where a patient needs a true pulsating blood supply. Specifically, axial and peristaltic pumps are typically left on in a continuous operation mode, where a steady stream of blood is supplied on a continuous basis, as opposed to the natural rhythm of the heart, which acts on a periodic, pulse-producing basis. In addition, such pumps are still largely in the developmental or trial phase.
Because of the inherent performance limitations of these ventricular assist devices, pneumatic devices would seem to be a good choice for providing pulsing pulmonary augmentation. However, as mentioned above, pneumatic ventricular assist devices are prone to failure and can cause blood damage and clotting. Moreover, the driver units for operating the pneumatic ventricular assist devices are motor-based (therefore, generally mechanically unreliable), and can only offer a simple cyclical pressure mode of operation, i.e., a repeating minimum and maximum pressure applied to the VAD bladder, which cannot be adjusted for particular patient conditions.
Accordingly, a primary object of the present invention is to provide a driver for pneumatic ventricular assist devices that is more reliable, that has no electrical pump or motor, and that provides a greater degree of operational flexibility and customization.
SUMMARY
A gas powered driver or driver means for a pneumatic ventricular assist device (VAD) is powered by pressurized air, oxygen or any other gas commonly available in hospital rooms, intensive care units and operating rooms. The driver can provide both blood-ejecting pressure (systole) and blood-filling vacuum (diastole) to the VAD. The driver is controlled by a computer/digital controller by means of pressure and volume sensors, and electromechanical, computer-controlled valves. Ventricular pumping is performed by a single spring-loaded piston or bellows inside a pump cylinder. The computer can actively regulate maximum systolic ventricular pressure, maximum diastolic vacuum, cycling rate and/or ejection volume (depending on the operating mode). The driver is also capable of automatically and periodically venting the drive line to eliminate condensation and foul air. The absence of a motor or electrical pump make the device small, reliable, easy to handle, and inexpensive.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features, aspects, and advantages of the present invention will become better understood with respect to the following description, appended claims, and accompanying drawings, in which:
FIG. 1 is a schematic diagram of an air-pressure powered driver for pneumatic ventricular assist devices, according to the present invention;
FIGS. 2A & 2B are schematic diagrams of a portion of the air-pressure powered driver in operation; and
FIGS. 3A–3C are various views of the air-pressure powered driver as implemented as a wheeled, portable cart.
DETAILED DESCRIPTION
With reference to FIG. 1 , a preferred embodiment of a gas pressure powered driver or driver means 10 for driving a pneumatic ventricular assist device 12 (VAD) includes a console unit 14 and a pressurized air/gas unit 16 , which includes one or more backup tanks (e.g., 18 a , 18 b ) of pressurized gas (preferably air) and a gas input connector 20 that attaches to a facility-wide pressurized air line 22 . The console unit 14 includes a computer or other electronic controller 24 , a pump cylinder or positive-displacement pump (i.e., piston or bellows) 26 with a sealed, gas moveable member 28 (i.e., piston or bellows), an inlet pressure valve 30 , and a cylinder venting valve 32 , both of which are attached to the pressurized air source 16 and the source (or input) end of the pump cylinder 26 . A tubular outlet “driveline” (i.e., a line that can be pressurized to drive a device) 34 is connected to the discharge or output of the pump 26 . The driveline, in turn, is attached to the ventricular assist device 12 . In use, at the beginning of a cycle, the computer 24 opens the inlet pressure valve 30 to compress the bellows and spring 28 and raise the systolic pressure in the VAD 12 (active systole). Once the maximum desired driveline pressure is achieved, as measured by a driveline pressure sensor 36 electrically connected to the computer 24 , the inlet pressure valve 30 is closed and the computer 24 waits (passive systole) until the desired blood volume is ejected from the VAD (volume-limited mode) or the systolic time has elapsed (frequency-limited mode). Diastole begins by opening the cylinder venting valve 32 . The compressed spring inside the bellows 28 then creates a vacuum for the blood-filling phase of the cycle (i.e., as the spring pushes the bellows outwards, the gas pressure in the driveline 34 , connected to the VAD 12 , decreases). Once the desired vacuum level is reached, as measured by the driveline pressure sensor 36 , a vacuum regulating valve 38 (attached to the driveline 34 ) opens to let air into the VAD/inner piston space/driveline 34 insuring that the desired vacuum level is not exceeded. The computer 24 then waits for the desired blood volume to fill the VAD 12 (volume-limited mode) or until the diastolic time has elapsed (frequency-limited mode).
As noted above, the preferred driver means 10 utilizes controlled pressurized air for operating the VAD 12 , as supplied to the console 14 from the pressurized air unit 16 , and not a motor-driven pump or the like. The pressurized air unit 16 may be separate from the console 14 , or attached thereto, e.g., as part of a mobile cart or the like (see FIGS. 3A–3C ). The primary source of pressurized air is the pressurized air, oxygen or other gas supply 22 found in most hospital rooms, intensive care units, and operating rooms, which is connected to the unit 16 by the connector 20 . The inlet pressure needs to be several times greater than the maximum systolic pressure desired, which is about 5 psi. Standard hospital oxygen and air supplies are regulated for fifty psi of pressure, which may be regulated by a regulator/alarm unit 40 positioned between the console 14 and the tanks 18 and supply line 22 . The tanks 18 a , 18 b are provided as a backup in case the main supply line 22 is shut off, or where portability is needed. A selector valve 42 , either computer-controlled or manual, is provided for selecting between the supply line 22 and tanks 18 a , 18 b . The regulator/alarm unit 40 may be configured to emit an alarm if the input pressure into the regulator/alarm unit 40 , i.e., the line pressure or tank pressure, falls or drops below a certain level.
An inlet pressure sensor 44 , in fluid communication with the console's pressurized air input line 46 and electrically connected to the computer 24 , may be provided to issue a signal to the computer 24 to warn the user if the inlet pressure drops due to a supply failure.
The computer 24 can be of any appropriate design or configuration. In one exemplary embodiment, the computer 24 comprises a microcontroller or microprocessor 50 and associated standard components (RAM, I/O bus, etc.), a video controller 52 and display 54 operably connected to the microcontroller 50 , a communications bus or port 56 (e.g., USB, Ethernet) for external access to the microcontroller, and an A/D and D/A converter 58 or other sensor/valve interface or control unit. The computer 24 also includes a speaker 60 for sounding alarms or the like.
Remaining components will be described with respect to the operation of the air-pressure powered driver 10 .
Pneumatic ventricular assist devices work by applying air pressure to a bladder or sac effectively attached in parallel to a patient's heart. Specifically, when pressure is applied to the sac, blood in the sac is ejected. When the air pressure against the sac is reduced, the sac expands, causing blood to enter the sac. When appropriate directional valves are employed, this creates a pulsing or cyclical blood flow. According to the present invention, with reference to FIGS. 2A and 2B , this action is accomplished using computer-controlled valves, a source of pressurized air, and the pump cylinder with spring-loaded bellows or piston.
As shown in FIG. 2A , at the beginning of a cycle, the computer 24 opens the inlet pressure valve 30 . This causes air to enter into the inlet side (i.e., intake chamber or input chamber) of the pump cylinder 26 , which compresses the bellows and spring 28 (it should be noted that the intake chamber of the cylinder is sealed or separate from the outlet side or discharge chamber). Compressing the bellows 28 causes the pressure of the air/gas in the driveline 34 to increase, which in turn compresses the VAD bladder or sac 70 , forcing blood out of the sac, through a VAD outlet valve 72 , and into the patient's bloodstream.
Once the maximum desired pressure in the driveline 34 is achieved, as measured by the driveline pressure sensor 36 , the inlet pressure valve 30 is closed and the computer 24 waits (passive systole) until the desired blood volume is ejected from the VAD 12 (volume-limited mode) or the systolic time has elapsed (frequency-limited mode). If the diastolic vacuum has not been established or is below the desired level (i.e., the driveline pressure is above the desired diastolic vacuum level), the computer 24 causes the vacuum regulating valve 38 to open momentarily to let a small amount of air escape the driveline 34 at the end of the systolic period.
As shown in FIG. 2B , diastole begins by opening the cylinder venting valve 32 . The compressed spring inside the piston cylinder or bellows will then create a vacuum for the blood-filling phase of the cycle. Specifically, as pressurized air is let out of the cylinder 26 , there is no longer enough pressure to counteract the spring in the bellows 28 . The spring forces the bellows/piston 28 outwards, increasing the effective volume of the driveline 34 and reducing the air pressure therein. This causes the VAD bladder 70 to expand, drawing in blood through a one-way VAD inlet valve 74 . Once the desired vacuum level is reached, as measured by the driveline pressure sensor 36 , the vacuum regulating valve 38 is opened to let air into the driveline 34 insuring that the desired vacuum level is not exceeded. If the desired vacuum level is not reached then it will be adjusted for the next cycle by opening the vacuum regulating valve 38 as discussed above. The computer 24 then waits for the desired blood volume to fill the VAD (volume-limited mode) or until the diastolic time has elapsed (frequency-limited mode).
The blood volume in the VAD 12 can be measured directly by a sensor in the VAD chamber (not shown). The blood volume in the VAD blood sac need not be measured directly, however, allowing for a simpler VAD design, but can be indirectly calculated by the computer 24 (calibrated to the VAD and driveline deadspace) by using Boyle's law (assuming a constant temperature, P 1 ·V 1 =P 2 ·V 2 ) and measuring the displaced volume in the pump cylinder 26 and driveline and barometric pressures. The barometric pressure and displaced volume can be measured by having, respectively: (i) a barometric pressure sensor 80 operably attached to the computer 24 ; and (ii) a distance sensor 82 (LED, other optical sensor, or the like) in the pump cylinder 26 and operably connected to the computer 24 , that measures the distance from one end of the pump cylinder to the bellows (or another appropriate measurement).
A safety pressure relief valve 84 is attached to the driveline 34 to insure that maximum VAD/driveline pressure (e.g., 5 psi) is never exceeded, which could lead to air leaks in the VAD 12 .
Periodically or at user selected times, the driver 10 has the capability of venting the driveline 34 to prevent excess condensation and remove fouled air. This is accomplished at the end of the diastolic period by opening a driveline venting valve 86 , positioned between the driveline 34 and the pressurized air input line 46 , for a short time.
The VAD/inner-cylinder/driveline space 34 is pressurized with fresh air. Excess pressure is vented by the pressure relief valve 84 . Then the vacuum regulating valve 38 is opened to vent the system.
The computer 24 is an electronic controllinf means for regulating maximum systolic ventricular pressure and maximum from a patient's heart, through the amount of gas selectively supplied to the pump's intake and exhaust chambers, wherein the computer 24 has the capability of controlling the entire process (mentioned in the paragraphs above) according to user selectable or manufacturer's preset parameters such as desired stroke volume, rate, VAD output, systolic to diastolic ratio, maximum diastolic volume, minimum systolic volume, maximum systolic pressure, and/or maximum diastolic vacuum. The computer, through its sensors, also has self diagnostic capabilities and can trigger warnings and alarms to the user. Finally, the computer may also have the capability of storing or relaying the operational status and performance of the driver to remote locations (nurses' station, doctor's office) via network or wireless communications 56 .
Although the VAD pumping action is primarily effectuated using pressurized air, the computer, valves, and sensors are electrically powered, via a standard power supply (attached to a wall outlet), generator, battery power system, or the like (not shown).
Silencers or mufflers 88 may be attached to the outputs of the valves 32 , 38 , for minimizing noise as pressurized air is periodically let out of the driver's air lines.
An emergency foot pump or bellows 90 may be operably attached to the driveline 34 , via a manual selector valve 92 and/or connector 94 . In an emergency (i.e., complete loss of pressurized air and/or electrical power), the foot bellows 90 are pumped manually, causing a variable pressure to be applied to the VAD 12 . Preferably, the air volume displaced by the bellows 90 is configured to generally match the displacement volume required for operating the VAD pumping sac 70 .
FIGS. 3A–3C show how the air-pressure powered driver 10 can be implemented as a portable cart.
Although the air-pressure powered driver has been described as having separate air inlet and pump venting valves 30 , 32 , respectively, a unitary air distribution device could be used instead, i.e., a computer-controlled device with three states: (i) “closed;” (ii) open to ambient (possibly through a muffler); and (iii) open to air input line 46 . This is also the case for the valves 38 , 84 , 86 on the driveline 34 . Thus, the term “air distribution device,” as used herein, refers both to: stand-alone, discreet valves; multi-state valves; or a combination of the two.
Although the air-pressure powered driver has been illustrated as having a spring-loaded bellows or piston in the pump, a different biasing mechanism other than a spring could be used instead (polymer members, motor units, constructing the bellows out of a deformable material with a material memory, etc.). Accordingly, the term “biased air movement member” incorporates any bellows, pistons, or the like biased with a spring or other suitable device.
Since certain changes may be made in the above-described air-pressure powered driver for pneumatic ventricular assist devices, without departing from the spirit and scope of the invention herein involved, it is intended that all of the subject matter of the above description or shown in the accompanying drawings shall be interpreted merely as examples illustrating the inventive concept herein and shall not be construed as limiting the invention.
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A driver for a pneumatic ventricular assist device (VAD) is powered by pressurized air, oxygen or any other gas commonly available in hospital rooms, intensive care units and operating rooms. The driver can provide both blood-ejecting pressure (systole) and blood-filling vacuum (diastole) to the VAD. The driver is controlled by a computer/digital controller by means of pressure and volume sensors, and electromechanical valves. Ventricular pumping is performed by a single spring-loaded piston or bellows. The computer can actively regulate maximum systolic ventricular pressure, maximum diastolic vacuum, cycling rate and/or ejection volume (depending on the operating mode). The driver is also capable of automatically and periodically venting the drive line to eliminate condensation and foul air. The absence of a motor or electrical pump make the device small, reliable, easy to handle, and less expensive.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to methods and apparatuses for loading bulk material into containers. More particularly, the invention relates to methods for loading scrap metal and steel into freight containers, and apparatuses thereof.
[0003] 2. Description of the Related Art
[0004] Efficiency and speed are important in the freighting industry. Decreasing the time necessary to load material into a freight container, transport the container, and unload the material from the container usually translates into greater profits for those involved in the process. One way the industry has increased efficiency has been to standardize the sizes of its freight containers, as defined by the ISO 668 standard. The use of standard sized freight containers allows tractor-trailers, ships, trains, and other freight carriers to quickly load and unload containers and to optimally utilize their available space. While freight containers come in several standard sizes, the most common sizes are the standard 40′, the 40′ high-cube, and the standard. 20′. The minimum internal height of most ISO standard shipping containers is 7′ 8 ½″, while the minimum internal width is 7′ 7 ¾″.
[0005] The use of such standard internal minimum dimensions generally permits quick loading and unloading of standard sized pallets onto freight containers while maximizing the use of available space in the containers. Not all materials, however, are suitable for palletization. For instance, bulk material, such as scrap metal, generally should not be palletized because such material varies widely in shape. As a result, many pieces of the bulk material are too large to fit within a pallet and must be either loaded separately into the container or cut into smaller pieces. Even when the bulk material is small enough to fit within a pallet, the space in the pallet is generally severely underutilized because of the bulk material's irregular shape. Because of the problems associated with palletizing bulk material, other methods for loading bulk material into freight containers have been developed.
[0006] One method to load bulk into a freight container is to use a conveyer belt. In this way, bulk material is placed on a conveyer belt that leads from outside of the container, through a door in the container, and terminates at an opposite closed end of the container. When the material reaches the end of the conveyer belt, it falls off the belt and is thus placed in the container. There are several problems with this method. First, the size of the conveyer, coupled with the irregular shaped bulk material, makes it difficult to utilize a high percentage of the available space in the container; there simply is not enough clearance in the container to permit stacking bulk material beyond a certain height. Also, the size of the bulk material, particularly Heavy Melting Scrap (“HMS”), is often too large to be properly transported using the conveyer belt, requiring the bulk material to be further shredded or otherwise reduced in size before being loaded. Moreover, it is not uncommon to have irregularly shaped pieces of material to impact with the sidewalls of the container while being loaded. Such impacts can severely damage the sidewalls, which are generally very thin. Such impacts are especially common when loading HMS.
[0007] Another method to load bulk material into a freight container is to use a skid loader. When using a skid loader, the bulk material is carried into the container and then dumped in place. This method is also less than satisfactory. Errors in operation of the skid loader can lead to physical injuries to workmen, and can also easily damage the sidewalls and ceiling of the container. Also, only small skid loaders can be used because of the relatively small size of the containers in which they are to operate. The use of small skid loaders requires operators to make numerous trips between the bulk material pile and the freight container. Furthermore, because the skid loader operates by lifting its bucket and then dropping its load, it is impossible to load material above a certain height within the container, decreasing the effective utilization of the container.
[0008] U.S. Pat. No. 7,172,382 to Frankel (“Frankel”), discloses an additional method and apparatus for loading bulk material into a freight container. Frankel discloses a loading assembly including a support structure, a load bin having a cross section conforming to an open end of a container, and a drive mechanism configured to urge the load bin into and out of the container. When fully inserted, the contents of the load bin are disposed within the container. The loading assembly further includes a barrier configured to keep the load confined within the container while the load bin opens to allow the load to remain within the container upon retraction of the load bin. The barrier projects above the top of the load bin to follow the frame of the support structure, and is not inserted into the container. The device disclosed by Frankel is unsatisfactory, as it is overly complicated and expensive. It has numerous moving parts and drive mechanisms which are susceptible to failure, requiring costly repairs and decreasing loading efficiency.
[0009] Thus, better apparatuses and methods for loading bulk material into freight containers are needed.
BRIEF SUMMARY OF THE INVENTION
[0010] Accordingly, disclosed are apparatuses and methods for use thereof for loading bulk material into freight containers.
[0011] In one embodiment, an apparatus for loading material into a shipping container is disclosed. The apparatus comprises a hopper and a ram. The hopper is sized and shaped to receive the material and be at least partially enclosable by the container to occupy a substantial volume of the container. The hopper comprises a first end and a second, substantially open end positioned opposite the first end. The ram comprises a plate and a driver. The plate has a width less than an internal width of the hopper and a height that does not extend beyond a top of the hopper. The plate is configured to move between the first end and the open end of the hopper. The driver is configured and capable of moving the plate between the first end and the open end to load the material into the shipping container. Optionally, the driver comprises a hydraulic cylinder.
[0012] In another embodiment, the apparatus further comprises a stand mounted near the first end of the hopper. The stand is configured to support the hopper above the ground at a height approximately equivalent to the height of the container above the ground. Optionally, the stand remains stationary with respect to the hopper.
[0013] In one embodiment, the apparatus further includes collapsible legs configured to support the hopper above the ground at a height approximately equivalent to the height of the container above the ground when the collapsible legs are extended. In one embodiment, the collapsible legs are mounted to the hopper. In another embodiment, the collapsible legs are mounted to the ground. In one, embodiment, the collapsible legs are configured to collapse upon impact with the container. Optionally, the apparatus further comprises a hydraulic mechanism attached to the collapsible legs to collapse the legs prior to impacting the container. In another embodiment, the hopper comprises recesses for receiving the collapsible legs, thereby giving the hopper a flat bottom surface when the collapsible legs are collapsed.
[0014] A method of loading a shipping container with material is also disclosed. The method comprises: (a) providing a loader comprising a hopper with a first end and a second, substantially open end opposite the first end; (b) loading the material into the hopper; (c) partially enclosing at least a portion of the hopper within the container; and (d) pushing the material towards the open end while moving the container away from the hopper.
[0015] Optionally, the loader further comprises a hydraulic cylinder coupled to a plate positioned adjacent the material, and step (d) comprises operating the hydraulic cylinder to push the plate towards the open end. In another embodiment, the loader further comprises a walking floor including a plurality of slats and a drive mechanism supporting the material, and step (d) comprises operating the walking floor to push said material towards said open end.
[0016] In an embodiment, the loader comprises support legs and further comprises the step of extending the support legs to support said hopper.
[0017] In one embodiment, the container is attached to a flatbed tractor-trailer.
[0018] Optionally, step (c) comprises: positioning the container in front of the hopper; moving the container backwards towards the hopper; and enclosing at least a portion of the hopper in the container.
[0019] In one embodiment, the material is pushed towards the open end at a predetermined speed and the container is moved away from the hopper at approximately the same speed.
[0020] In yet another embodiment, the support legs are collapsed upon impact with the container. In another embodiment, the support legs are collapsed prior to being impacted by the container.
[0021] In an additional embodiment, step (d) comprises putting the flatbed tractor-trailer in neutral, thereby causing the material to push the flatbed tractor-trailer forward. In another embodiment, step (d) comprises driving the flatbed tractor-trailer forward.
[0022] A hopper for loading material into a shipping container is also disclosed. The hopper comprises: a first end; a second, substantially open end positioned opposite the first end; and a reciprocating conveyor floor system extending from the first end to the second end. The reciprocating conveyor floor comprises a plurality of horizontal slats and a drive mechanism configured to move groups of slats in an alternating manner. The hopper is sized and shaped to be at least partially enclosable by the container to occupy a substantial volume of the container.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] For a more complete understanding of the present invention, the objects and advantages thereof, reference is now made to the following descriptions taken in connection with the accompanying drawing in which:
[0024] FIG. 1 illustrates a container and a bulk material loader, according to an embodiment of the invention, for use therewith.
[0025] FIG. 2 illustrates a side view of the container and the bulk material loader of FIG. 1 .
[0026] FIG. 3 illustrates a top view of the container and the bulk material loader of FIG. 1 .
[0027] FIG. 4 illustrates top views of a bulk material loader with a reciprocating conveyor floor system, according to an embodiment of the invention, for use therewith.
[0028] FIG. 5 illustrates a side view of the container and the bulk material loader when the bulk material loader is inserted into the container, according to an embodiment.
DETAILED DESCRIPTION OF THE INVENTION
[0029] Referring to FIG. 1 , depicted is a bulk material loader 100 , according to an embodiment of the invention, and a container 102 mounted on a flatbed tractor-trailer (only the rear wheels of the flatbed tractor-trailer are shown). In one embodiment, the container 102 is a standard sized container used in the freight industry, and can be a standard 40′, the 40′ high-cube, the standard 20′, or another common sized container. The bulk material loader 100 comprises a hopper 104 . The hopper 104 is suitable to withstand the loading and unloading of bulk material, including HMS, without being damaged. In one embodiment, the hopper 104 is constructed to support and withstand loads in excess of 66,000 pounds, although the loader of the present invention can be constructed to load materials of less than or greater than 60,000 pounds. Referring briefly to FIG. 2 and FIG. 3 , it is apparent that the height and width of the hopper 104 is less than, and preferably slightly less than, the internal height and width of the container 102 . Accordingly, as depicted in FIG. 5 , the hopper 104 can be at least partially enclosed by the container 102 . The exact height and width of the hopper 104 will depend on its specific application, but in one embodiment, the hopper 104 is slightly less than 7′ 8″ tall and slightly less than 7′ 7″ wide, thereby permitting the hopper 104 to fit within most ISO containers. The length of the hopper 104 will also depend on its specific application. In one embodiment, the hopper 104 is at least 40′ long, thereby permitting the hopper 104 to occupy substantially the entire volume of most standard sized containers, as depicted in FIG. 5 . The hopper 104 comprises an open end 116 to permit bulk material to be expelled from the hopper 104 into the container 102 . In some embodiments, and as illustrated in FIG. 1 , the hopper 104 further comprises, for example, a steel frame supporting a steel bottom and two steel sides. In other embodiments, as illustrated in FIG. 4 , the hopper 104 comprises, for example, a steel frame supporting a reciprocating conveyor floor system 400 and two steel sides.
[0030] Referring now to FIG. 4 , the reciprocating conveyor floor system 400 , also known as a walking floor, is well known to those skilled in the art, and extends from a back end 114 to the open end 116 of the hopper 104 . The floor system 400 comprises a plurality of horizontal floor slats 402 and at least one drive mechanism (not shown), typically mounted below the slats 402 , configured to move groups of slats in an alternating manner. In one embodiment, every third slat is a member of the same group and is moved in unison, and the floor system 400 operates in a four step process. In Step I, all three groups of floor slats 402 ′ are extended out through the open end 116 of the hopper 104 approximately the same distance. This motion causes all the bulk material loaded in the hopper 104 to be pushed slightly forward towards the open end 116 of the hopper 104 . The bulk material closest to the open end 116 of the hopper 104 is moved through the open end 116 and out of the hopper 104 while still being supported by the floor system 400 . In Step II, the first group of floor slats 402 of the floor system 400 is retracted into the hopper 104 to its original position. During this retraction, the first group of floor slats 402 changes its position relative to all of the bulk material supported by the floor system 400 . The bulk material external to the hopper 104 remains supported by the second and third group of floor slats 402 . In Step III, the second group of floor slats 402 is retracted into the hopper 104 to its original position. Again, this retraction causes the second group of floor slats 402 to change its position relative to the bulk material supported by the floor system 400 . At this point, the bulk material external to the hopper 104 is supported only by the third group of floor slats 402 . Finally, in Step IV, the third group of floor slats 402 is retracted into the hopper 104 to its original position. This last retraction causes the third group of floor slats 402 to change its position relative to all of the bulk material, and causes the bulk material external to the hopper 104 to no longer be supported by the floor system 400 . As a result, this external bulk material is expelled into the standard container (not shown). Steps I-IV are repeated until all of the bulk material has been unloaded from the hopper 104 .
[0031] Referring back to FIG. 1 , the bulk material loader 100 , in some embodiments, further comprises a ram 118 . The ram 118 comprises a plate 106 and a driver 108 . In one embodiment, the plate 106 is sized to fit snuggly to the bottom and sides of the hopper 104 . In a preferred embodiment, the plate 106 is made of a heavy duty steel material. In an embodiment, the plate 106 blocks the back end 114 of the hopper 104 to prevent bulk material from accidentally being expelled from the hopper 104 . The plate 106 is attached to the driver 108 . The driver 108 is a mechanical device configured to move the plate 106 between the back end 114 and the open end 116 of the hopper 104 to load material into the container 102 . In an embodiment of the invention, the driver 108 is capable of moving at least 22,000 pounds. In another embodiment, the driver 108 is capable of moving at least 58,000 pounds.
[0032] In an embodiment of the invention, as depicted in FIG. 1 , the driver 108 is a hydraulic cylinder. In this embodiment, the plate 106 is attached to the hydraulic cylinder's adjustable piston rod. Thus, when the piston rod of the driver 108 is extended, the plate 106 is pushed from the back end 114 of the hopper 104 to the front open end 116 of the hopper 104 . The hydraulic cylinder is any standard hydraulic cylinder, well known to those skilled in the art, capable of pushing scrap metal or similar bulk material out of hopper 104 . As is apparent to those skilled in the art, the hydraulic cylinder is part of a hydraulic system (not shown), the main components of which are a hydraulic pump, a hydraulic cylinder, and a series of electrical controls. When the driver 108 is a hydraulic cylinder, the length of the hydraulic cylinder varies based on the length of hopper 104 . In one embodiment, as most clearly depicted in FIG. 2 and FIG. 3 , the hydraulic cylinder is long enough to adjust the position of the plate 106 from the back end 114 of the hopper 104 to the front open end 116 of the hopper 104 .
[0033] Those skilled in the art will recognize that the driver 108 need not be a hydraulic cylinder, and can be any mechanical device(s) capable of moving the plate 106 between the back end 114 and the open end 116 of the hopper 104 . Thus, in one embodiment, the driver 108 comprises a chain or belt drive (not shown) connected to the plate 106 . In another embodiment, the driver 108 comprises a rack and pinion setup (not shown), where the pinion is connected to a motor to drive the rack forward and or backward. The pinion is connected to the plate 106 to move the plate 106 between the back end 114 and the open end 116 of the hopper 104 . In yet another embodiment, driver 108 is a screw system (not shown) designed to move the plate 106 between the back end 114 and the open end 116 of the hopper 104 . All of these configurations including their operations are well known to those skilled in the art.
[0034] In another embodiment, the bulk material loader 100 further comprises a stand 110 onto which the hopper 104 is mounted. In one embodiment, most clearly depicted in FIG. 2 , the hopper 104 is mounted to the stand 110 such that hopper 104 is off the ground and positioned at approximately the same height as the container 102 . In this way, the hopper 104 can easily be partially enclosed by the container 102 without having to alter the distance between the ground and the container 102 or the hopper 104 . As will be apparent, the exact height of the hopper 104 off the ground will depend on the specific application. In one embodiment, the hopper 104 is mounted to the stand 110 such that the hopper 104 is approximately 5 ′ off the ground. In another embodiment, the hopper 104 is mounted such that it is between approximately 3′ 2″ and 3′ 4″ off the ground. The stand 110 is made from heavy duty steel and, in some embodiments, is capable of supporting the entire weight of the loaded hopper 104 , thereby preventing the bulk material loader 100 from tipping over or otherwise being damaged. In one embodiment, the stand 110 is counterbalanced with concrete blocks or a similar material (not shown) to enable the stand 110 to support the weight of the hopper 104 . All or part of the driver 108 can also be mounted to the stand 110 as necessary, depending on the specific implementation of the driver 108 . Thus, when the driver 108 is a hydraulic cylinder, as depicted in FIG. 1 , the driver 108 is mounted to the stand 110 .
[0035] Referring to FIG. 1 and FIG. 2 , in another embodiment, the bulk material loader 100 also comprises collapsible support legs 112 . These support legs 112 prevent the bulk material loader 100 from tipping over under heavy loads and allow the hopper 104 to be loaded quicker in high volume operations. The support legs 112 collapse towards the stand 110 , thereby enabling portions of the hopper 104 beyond the point of the support legs 112 to occupy space within the container 102 . Once the support legs 112 have collapsed, any necessary support is provided by the container 102 and flatbed. In one embodiment, the support legs 112 are hingedly mounted to the bottom of the hopper 104 . In a more detailed embodiment, the bottom of the hopper 104 has recesses configured to receive the collapsed support legs 112 . In this embodiment, when the support legs 112 collapse they are received in complimentary recesses, giving the hopper 104 a flat bottom and preventing the support legs 112 from protruding beyond the bottom of the hopper 104 when collapsed. Thus, the support legs 112 are protected from damage when collapsed, and weight not supported by the stand 110 is transferred through the entire portion of the hopper 104 inside the container 102 to the container 102 and flatbed. In one embodiment, the bottom of the hopper 104 includes multiple rollers to facilitate the movement of the container 102 relative to the hopper 104 . In another embodiment, the collapsible support legs 112 are hingedly mounted to the ground. In this embodiment, the usable space of the hopper 104 is increased because clearance for the support legs 112 inside the container 102 is no longer required. For example, the legs 112 can be mounted to a foundation provided on the ground with a hydraulic line connected to it.
[0036] In accordance with an embodiment of the invention, operation of the bulk material loader 100 proceeds as follows. First, the length of the container 102 must be determined to set the position of the piston rod of the driver 108 and thus the position of the plate 106 in the hopper 104 . For instance, if the container 102 is a standard 20′, then only 20′ of the hopper 104 or less can be used to occupy space within the container 102 . For example, in this case, the piston rod of the hopper 104 must be set so that the plate 106 is 20′ from the front opening of the hopper 104 . If, on the other hand, the container 102 is a standard 40′ and the hopper 104 is 40′ long, then the piston rod must be fully retracted so that the plate 106 is at the back end 114 of the hopper 104 . Once the plate 106 is set in position, and the support legs 112 are extended (if necessary), the bulk material is loaded into the hopper 104 . Any type of material can be loaded, including HMS over 6′ in length. In one embodiment, the bulk material is dumped into the hopper 104 through the open top of the hopper 104 . Once the hopper 104 is loaded, the container 102 , still attached to the flatbed tractor-trailer, is positioned in front of the hopper 104 and is backed up to enclose the hopper 104 within the container 102 . If the support legs 112 are extended, they collapse when impacted by the container 102 . Alternatively, the support legs 112 are set to collapse prior to being impacted by the container 102 . As a result of the flatbed tractor-trailer backing up, the hopper 104 is at least partially enclosed by the container 102 , one embodiment of which is illustrated in FIG. 5 . At this point, the hydraulic system is activated to push the piston rod of driver 108 forward. The piston rod pushes the plate 106 , which in turn pushes the bulk material out of the front opening of the hopper 104 and into the container 102 . As bulk material is pushed into container 102 , the flatbed tractor-trailer moves forward so as to fill the container 102 with all of the material in the hopper 104 . In one embodiment, at the same time the hydraulic system is activated, the flatbed tractor-trailer is set to neutral. As a result of the bulk material being pushed into the container 102 , the flatbed tractor-trailer is pushed forward. In another embodiment, when the hydraulic system is activated, the flatbed tractor-trailer is slowly driven forward at approximately the same speed the hydraulic piston is pushing the plate 106 . In this manner, when the hydraulic piston of the driver 108 is fully extended, all of the bulk material that was in the hopper 104 is pushed into the container 102 . Once all of the material is loaded in the container 102 , the flatbed tractor-trailer pulls forward, the container 102 doors are closed, and the flatbed tractor-trailer drives away.
[0037] Referring now to FIG. 1 , embodiments of the invention have several advantages over the prior art. For instance, the bottom and side walls of the hopper 104 prevent the container 102 from coming into contact with the bulk material when the bulk material is moving with respect to the container 102 . Thus, at no point can the container 102 suffer damage from the bulk material. Furthermore, the bulk material loader 100 has few moving parts. In one embodiment, only the driver 108 and the plate 106 move, leading to less wear and tear on the loader 100 , and less chance for damage and costly repairs. In another embodiment, the bulk material loader 100 utilizes a readily available reciprocating conveyor floor system (not shown), reducing costs and deployment time. Also, in some embodiments, a flatbed tractor-trailer engine is used in the loading process to reduce the amount of work to be done by the bulk material loader 100 , again reducing costs and the likelihood of failures.
[0038] While in accordance with the patent statutes, description of the various embodiments and examples have been provided, the scope of the invention is not to be limited thereto or thereby. Modifications and alterations of the present invention will be apparent to those skilled in the art without departing from the scope and spirit of the present invention.
[0039] Therefore, it will be appreciated that the scope of this invention is to be defined by the appended claims, rather than by the specific examples which have been presented by way of example.
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Disclosed are apparatuses and methods for use thereof for loading bulk material into freight containers. One apparatus comprises a hopper configured to receive bulk material that is sized and shaped to be at least partially enclosable by a container to occupy a substantial volume of the container and a ram. The ram comprises a plate and a driver configured to move the plate from a back end of the hopper to an open end of the hopper to expel material into a container. Another apparatus comprises a hopper configured to receive bulk material that is sized and shaped to be at least partially enclosable by a container to occupy a substantial volume of the container and a reciprocating conveyor floor system. Optionally, the apparatuses further include a stand and/or collapsible legs to further support the hopper.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to computers and, more particularly, to the management of updates for computer software. A major objective of the present invention is to provide for optimally selecting updates for a given hardware/software configuration.
[0002] Much of modern progress is associated with the increasing prevalence of computers. Computers include one or more processors and memory. The memory stores data and instructions; a processor manipulates data by executing instructions. Instructions are organized into programs to perform meaningful work. While the first programs were quite simple, the size and complexity of the most sophisticated programs have increased exponentially.
[0003] Almost inevitably, it becomes necessary or desirable to modify a program: 1) to correct a defect, 2) to address a compatibility issue with other software or hardware, 3) to improve performance, and/or 4) to add features. (If no new features are added, the update is called a “patch”; if new features are added, the update is called an “upgrade”.) Instead of replacing an entire program, the program can be updated. Updating can involve actually changing the instructions in a monolithic program. However, partly to facilitate updates, programs are often configured as a group of files so that an update can simply involve a replacing a preexisting file with an update file.
[0004] Update installation can be problematic if the update renders a program incompatible with a program that was previously compatible. Typically, “uninstall” programs are available to restore the pre-update state of the computer. However, the objective of the update is then not accomplished.
[0005] Often, available updates are not installed. A user may avoid changing a system that is serving its purpose well; or a user may not be aware of an update's availability. In such cases, available updates can be superseded one or more times before a user tries to update. This can present a choice of updates. Normally, the most recent update is installed. However, if the most recent update is unsuccessful, e.g., raises new compatibility issues, optimizing the selection of updates can be problematic.
[0006] Update selection can be difficult for a number of reasons. In the first place, one update may be dependent on another update having been installed. In addition, update successions can be complex since one update can supersede more than one prior update. What is needed is a way to improve update selection when there is a complex succession of updates.
SUMMARY OF THE INVENTION
[0007] The present invention provides an update management system including an update chronology generator. In response to a request via a network received at an input of the system, the update chronology generator generates a chronology regarding a given target update. The chronology is generated by accessing a database record for the target update, as well as database records for updates indicated in the target-update record as being succeeded by the target update. The update management system can access a set of one or more databases including an internal database or an external database or both. Preferably, the chronology extends back to the “base” program, and also extends forward to indicate updates that succeed the target update.
[0008] The update chronology can be in the form of an update family tree or an update state sequence. In either case, the chronology can be used as a reference when troubleshooting a system. For example, where both an original update state and a fully updated state of a program cause compatibility problems, the update chronology presents intermediate states that may avoid these compatibility problems. When used in conjunction with update dependency information, the update chronology can help in removing unnecessary files from a computer—freeing storage capacity and improving performance. These and other features and advantages of the invention are apparent from the description below with reference to the following drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] [0009]FIG. 1 is a block diagram of an update management system in accordance with the present invention.
[0010] [0010]FIG. 2 is a flow chart of a method of the invention practiced in the context of the system of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0011] In accordance with the present invention, an update management system AP 1 comprises an update catalog server 10 and update files 11 . Update catalog server 10 includes a chronology generator 13 , a dependency generator 15 , an update index 17 , and a local update database 19 . The chronology generator and the dependency generator share a common interface 20 for accessing local update database 19 , as well as external databases. Update management system AP 1 is connected to a network 21 at a network port 22 , on which two update databases 23 and 25 reside. A remote workstation 31 on a remote network 33 communicates with update management system AP 1 via an inter-network link 35 .
[0012] The invention provides for use of one or more databases; each of which can be either local (part of update management system AP 1 ) or remote. Normally, when there are plural databases, they are mutually exclusive as to target updates represented. Alternatively, a local database can be used as a cache to improve performance.
[0013] Typically, requests are made to update management system AP 1 from a remote workstation, such as remote workstation 31 , and are received by update management system AP 1 at network port 22 . The requests are made for updates to a “base” program, typically residing on the remote workstation. The base program can be an operating system, a utility program, an application program, etc. The updates can be patches—which fix problems or improve performance without adding features, or upgrades, which add features, or both.
[0014] The request can be directed toward finding an appropriate update for a given computer system. To this end, the request can include information regarding the hardware configuration, operating system, and co-existing programs on the workstation. Alternatively, a request can concern a particular update. For example, a dependency request can be seek a listing of “prerequisite” files required by the target update.
[0015] Of particular interest herein, are “chronology” requests for an update chronology for a target update. For example, a chronology of patches leading up to a target patch from the initial release of the base program. Alternatively, the chronology can specify updates that supersede the target update. Most useful, is a chronology that indicates an entire succession from the base program, through the target update, to its most recent successor.
[0016] The response to a chronology request (command line: “$ pft PHKL — 8000”, where “PHKL — 8000” is a hypothetic target update) can be a family tree of the form:
PHKL_9000 PHKL_8000 PHKL_6000 | PHKL_3000 | | PHKL_1000 | PHKL_4000 | PHKL_5000 | PHKL_2000 PHKL_7000
[0017] Non-indented updates on succeeding lines are successor updates. In this case, PHKL — 8000 has been succeeded only by PHKL — 9000. If the latter had been succeeded, its successor would have been listed on the line above PHKL — 9000 and with the same indent. It is assumed herein that a target update can only be directly succeeded by one update. Hence, successor updates can be displayed linearly. If it is permitted for a single target update to have multiple direct successors, then the successor updates can be displayed in tree form, as are the predecessor updates.
[0018] It is often the case that an update will in effect merge two or more of its predecessors. Hence, the chain of succession up to a target update can have a tree-type structure. Updates that have a common successor are aligned vertically in the report. For example, PHKL — 6000 and PHKL — 7000 are aligned, since they are both succeeded by PHKL — 8000. Likewise, PHKL — 6000 succeeds PHKL — 3000, PHKL — 4000 and PHKL — 5000. The report also indicates that PHKL — 3000 supersedes only PHKL — 1000, and PHKL — 5000 supersedes only PHKL — 2000. All updates for which no predecessor is indicated are patches to the base program.
[0019] Several attributes can be displayed in the report. The report can include a one-line description for each update. In addition, the report can indicate: if an update has been recalled, whether it has dependencies, whether it is critical, and whether it has been reposted. The information included in the report can be determined by selections made in the request itself.
[0020] A method M 1 of the invention is flow-charted in FIG. 2. An update chronology request is received by update management system AP 1 at step S 1 . Update catalog server 10 handles this request. In particular, chronology generator 13 accesses update index 17 to determine the location of an update record for the target update at step S 2 . Update index 17 lists updates alphabetically and indicates a database and a record number for each update listed therein. The database can be local database 19 , considered part of update catalog server 10 , or it can be an external database, such as databases 23 and 25 at remote nodes on network 21 .
[0021] At step S 3 , chronology generator 13 accesses the database and target record identified in index 17 . For small systems with not too many updates, index lookup step S 2 is not necessary. However, the larger the number of records and databases, the more time is saved using the index in step S 2 .
[0022] The target record accessed in step S 3 must identify any updates directly superseded by the target update. Preferably, any immediate successor to the target update is also identified. Updates can be identified by name, or by database (if more than one) and record number, as they are in index 17 . Preferably, both name and database locations are given. The records can contain other information, notably, any prerequisite updates that are required to be installed if the target update is to function. (Note that dependency requests are normally handled by dependency generator 15 ).
[0023] At step S 4 , the records for any indicated immediate predecessors, step S 4 A, and for any indicated immediate successor, step S 4 b, are accessed. If the target record does not indicate the database locations of these records, chronology generator 13 can look up the locations in index 17 . Preferably, however, the target record does indicate database locations for the immediate successor and predecessors so this index step can be omitted for higher performance. If, at step S 4 A, the predecessor records indicate further predecessors update, step S 4 A is repeated. When, in step S 4 A, the only predecessor is the base program, the iteration stops. Likewise, if at step S 4 B, a further successor update is indicated, step S 4 B is iterated until a successor record is found with no successor update indicated.
[0024] Once all the records indicated in step S 4 are gathered, chronology generator 13 generates a family tree, as indicated in the example for PHKL — 8000 above. Optionally, a state list can be generated at step S 5 from the family tree. (Alternatively, the state list can be generated directly, without first generating a family tree.) The state list can indicate a series of workable update states. The following state list corresponds to the PHKL — 8000 family tree generated above, given that update names reflective the order in which they were introduced.
State List: PHKL_8000 Update Co-existing Updates (0) (Base program) PHKL_1000 (Base program) PHKL_2000 PHKL_1000 PHKL_3000 PHKL_2000 PHKL_4000 PHKL_2000 & PHKL_3000 PHKL_5000 PHKL_3000 & PHKL_4000 PHKL_6000 PHKL_7000 PHKL_6000 PHKL_8000 PHKL_9000
[0025] The family tree or the state table can be used in upgrading a system when the most recent updates cause problems. For example, assume workstation 31 had PHKL — 1000 and PHKL — 2000 installed at its last update. Also, assume a user for workstation 31 is advised to upgrade to PHKL — 8000 for higher performance. The user performs a chronology request and discovers that PHKL — 8000 has been superseded by PHKL — 9000. The user downloads and installs PHKL — 9000 from update manager system AP 1 . In addition, the user can issue a dependency request handled by dependency generator 15 to ensure all updates required by PHKL — 9000 are installed.
[0026] Assume that after proper installation, PHKL — 9000 causes compatibility problems with a key application program. The user uninstalls update PHKL — 9000, returning workstation 31 to its previous state. Instead of choosing only between the most recent update and the most-recent pre-update state, the family tree and state table present a number of intermediate alternatives. The user can work forward or backward through the chronology until the optimal state is found. For each state, dependency checks can be performed for each installed update to ensure that the proper dependency updates are also installed. Thus, the update catalog manager, in particular, the chronology generator, facilitates update optimization.
[0027] In addition, the chronology generator can be used to assist removal of unused updates. The dependencies of the replaced updates can be compared with the dependencies of the newly installed updates, and the dependencies that are no longer used can be subject to a reverse dependency analysis. If the reverse dependency analysis turns out negative, the former dependencies can be removed.
[0028] While the invention applies generally to updates, it has been implemented in the following patch-family-tree tool (pft) for patches. The following command-line syntax with switches can be used.
[0029] Usage: pft −o <os> [−p <platform>] [−s <servers>] [−v] [−l] [−r] [−e] [−c] [−a] [−y] [−z] [−i <number_of_spaces>] <patch_name_or —number>
[0030] where,
[0031] <os>=operating system version
[0032] examples: 10.20 11.00 11.04
[0033] <platform>={ 700 |800 } (ignored for 11.X)
[0034] <servers>=system1:port1[,system2:port2] [, . . . ]
[0035] −v=verbose (print one-line descriptions)
[0036] −l=show recalled patches
[0037] −r=show released patches
[0038] −e=show patches with dependencies
[0039] −c=show critical patches
[0040] −a=show reposted patches
[0041] −y=show superseded patches (“older”)
[0042] −z=show superseding patches (“newer”) (default is to show both)
[0043] <number_of_spaces>=to indent each generation (default and min=1; max=8)
[0044] The OS is specified with the −o option, and the hardware is specified with the −p option. The hardware platform is not required for any HP-UX 11.X releases.
[0045] The tool can be directed to a particular catalog server, or servers, using the −s option. This will override the default value, and any value(s) specified with the CATALOG_SERVERS environment variable.
[0046] A patch family tree is generated for a single patch and it must be specified on the command line.
[0047] The number of spaces in the indentation can be adjusted using the −i option. Increasing the number of spaces can improve readability of the output report.
[0048] The report can include one-line descriptions of each patch, by specifying the −v option, for “verbose” output.
[0049] By default, the report will contain patches that are both older than (superseded by) and newer than (supersede) the specified patch. Only the older patches are shown when the −y option is used. Only the newer patches are shown when the −z option is used.
[0050] Various attributes of the listed patches can be displayed using several options. If the patch has the requested attribute, a flag will be included in the output listing.
Output Option Flag Description -l RCL Patch has been recalled. -r REL Patch has been released in a Support Plus or Extension Software bundle. -e DEP, Patch has patch dependencies and/or other ODEP dependencies. -c CRIT Patch is flagged has containing critical defect fixes. -a REP Patch was reposted.
[0051] This following example shows the use of the −v (verbose) option and the −i (indentation) option, for the command line beginning with the “$”−sign below. The specified patch supersedes five patches: PHKL — 14070, PHKL — 14034, PHKL — 13676, PHKL — 13644, and PHKL — 13328. PHKL — 14070 supersedes one patch, PHKL — 13858, which supersedes PHKL — 13552, which supersedes PHKL — 13081.
[0052] $ pft −v −o 11.00 −i 3 −y 14088
[0053] #
[0054] # Patch Family Tree
[0055] # PHKL — 14088 HP-UX Performance Pack cumulative patch
[0056] # OS: 11.00
[0057] #
[0058] # Only superseded patches are displayed.
[0059] # Superseded patches are indented to the right
[0060] # and go down.
[0061] # Patches aligned in a vertical column are in the
[0062] # same “generation”.
[0063] #
[0064] PHKL — 14088 HP-UX Performance Pack; cumulative patch
[0065] PHKL — 14070 Tape, IOCTL, FC fixes cumulative patch
[0066] | PHKL — 13858 Tape and IOCTL fixes cumulative patch
[0067] | PHKL — 13552 Large record, seismic tape support
[0068] | PHKL — 13081 PCI EPIC arbitration timeout panic
[0069] PHKL — 14034 SHMEM_MAGIC Perf, Mem window patch
[0070] | PHKL — 13810 Memory Windows; pstat; space id
[0071] | | PHKL — 13278 User stack limits on 32/64 bit
[0072] | | PHKL — 13193 Fix panic:hdl_alloc_spaceid
[0073] | | PHKL — 13052 pstat(2) number of procs limit
[0074] | PHKL — 13646 Poor perf with SHMEM_MAGIC programs
[0075] PHKL — 13676 Fix C program error in badalignment( )
[0076] PHKL — 13644 Fix for panic in wait1( )
[0077] PHKL — 13328 Fix for panic in proc_close( )
[0078] The following example shows the use of the −y (display older patches) and the −r (denote recalled patch) options. Only patches that are superseded by the specified patch, PHCO — 12922, are displayed. The patches that supersede PHCO — 12992 (PHCO — 12923,
[0079] PHCO — 14842, and PHCO — 16591) are not displayed. Note the two recalled patches, PHCO — 11909 and PHCO — 11908, flagged with the “RCL” keyword.
[0080] $ pft −v −o 10.20 −p 800 −y −r 12922
[0081] #
[0082] # Patch Family Tree
[0083] # PHCO — 12922 fsck —vxfs( 1M) cumulative patch
[0084] # OS: 10.20
[0085] # PLATFORM: 800
[0086] #
[0087] # Only superseded patches are displayed.
[0088] # Superseded patches are indented to the right
[0089] # and go down.
[0090] # Patches aligned in a vertical column are in the
[0091] # same “generation”.
[0092] # RCL=Recalled patch
[0093] #
[0094] PHCO — 12922 fsck —vxfs( 1M) cumulative patch
[0095] PHCO — 11909 RCL fsck_vxfs(1M) cumulative patch
[0096] PHCO — 11908 RCL fsck_vxfs(1M) cumulative patch
[0097] PHCO — 11223 fsck_vxfs(1M) cumulative patch
[0098] PHCO — 10965 fsck_vxfs(1M) cumulative patch
[0099] PHCO — 9396 fsck − vxfs(1M) fix for file system
[0100] The recall notices for the “recalled” patches can be viewed using a query tool. The query tool, indicated by the abbreviation “qpc”, is used to send a message to the catalog server. Quite often this message takes the form of a query. The query tool reads a message from its command line arguments, sends it to the specified server, waits for the answer, and displays.
[0101] $ qpc 11909 Warn
[0102] PHCO — 11909:
[0103] Warn: 97/10/21—This patch has been recalled. —Patch PHCO — 11909 can cause OmniStorage A.02.20 filesystems to be unmountable on HP-UX 10.20. The problem is . . .
[0104] The following example shows the use of the −z (display newer patches) option, and the −e (display patches with dependencies) option. Note that each of the patches that supersede PHCO — 11909 has a dependency on at least one other patch.
[0105] $ pft −v −o 10.20 −p 700 −z −e 11909
[0106] #
[0107] # Patch Family Tree
[0108] # PHCO — 11909 fsck_vxfs(1M) cumulative patch
[0109] # OS: 10.20
[0110] # PLATFORM: 700
[0111] #
[0112] # Only superseding patches are displayed.
[0113] # Superseding patches are indented to the left
[0114] # and go up.
[0115] # Patches aligned in a vertical column are in the
[0116] # same “generation”.
[0117] # DEP =Patch has dependencies on other patch(es)
[0118] # ODEP =Patch has other dependencies
[0119] #
[0120] PHCO — 16591 DEP fsck_vxfs(1M) cumulative patch
[0121] PHCO — 14842 DEP fsck_vxfs(1M) cumulative patch
[0122] PHCO — 12923 DEP fsck_vxfs(1M) cumulative patch
[0123] PHCO — 12922 DEP fsck_vxfs(1M) cumulative patch
[0124] PHCO — 11909 DEP fsck_vxfs(1M) cumulative patch
[0125] The patch dependencies can be viewed using the patch dependency analysis tool “pdat”, as implemented by patch dependency generator 15 .
[0126] $ pdat −v −o 10.20 −p 700 16591
[0127] PHCO — 18563 LVM commands cumulative patch
[0128] PHKL — 16750 SIG_IGN/SIGCLD,LVM,JFS,PCI/SCSI cum. patch
[0129] PHKL — 16959 Physical dump devices configuration patch
[0130] PHKL — 17857 Fix for mount/access of disc sections
[0131] PHKL — 20610 Correct process hangs on ufs inodes
[0132] PHKL — 21594 VxFS (JFS) mount, fsck cumulative patch
[0133] PHKL — 21660 lo_realvfs panic fix, Cum. LOFS patch
[0134] PHNE — 19937 cumulative ARPA Transport patch
[0135] The following example shows the use of the −c (flag critical patches) option for a patch family tree command. Patches which have been released with Support Plus and/or Extension Software are flagged when the −r option is specified. PHCO — 14198 is a critical patch, and both PHCO — 14198 and PHCO — 13131 have been released in a Support Plus and/or Extension Software bundle.
[0136] $ pft −v −o 11.00 −i 3 −c −r 14198
[0137] #
[0138] # Patch Family Tree
[0139] # PHCO — 14198 crashutil(1M) cumulative patch
[0140] # OS: 11.00
[0141] #
[0142] # Both superseded and superseding patches are
[0143] # displayed.
[0144] # Superseded patches are indented to the right
[0145] # and go down.
[0146] # Superseding patches are indented to the left
[0147] # and go up.
[0148] # Patches aligned in a vertical column are in the
[0149] # same “generation”.
[0150] # REL=Patch released with Extension Software and/or
[0151] # Support Plus
[0152] #
[0153] # CRIT=Patch contains critical fixes
[0154] PHCO — 14198 REL CRIT crashutil(1M) cumulative patch
[0155] PHCO — 13131 REL crashutil(1M) cumulative patch
[0156] Critical fix information for a patch, and all patches that it supersedes, can be viewed using qpctree:
[0157] $ qpctree −f Crit 14198
[0158] PHCO — 14198:
[0159] Crit: PHCO — 14198::
[0160] Yes
[0161] CORRUPTION
[0162] PHCO — 13131::
[0163] No
[0164] The following example shows the use of the −a (flag reposted patches) option. In this example, PHCO — 10576 has been reposted.
[0165] $ pft −v −o 10.20 −p 800 −a 14967
[0166] #
[0167] # Patch Family Tree
[0168] # PHCO — 14967 sar(1M) cumulative patch
[0169] # OS: 10.20
[0170] # PLATFORM: 800
[0171] #
[0172] # Both superseded and superseding patches are
[0173] # displayed.
[0174] # Superseded patches are indented to the right
[0175] # and go down.
[0176] # Superseding patches are indented to the left
[0177] # and go up.
[0178] # Patches aligned in a vertical column are in the
[0179] # same “generation”.
[0180] # REP=Patch was reposted
[0181] PHCO — 14967 sar(1M) cumulative patch
[0182] PHCO — 14228 sar(1) cumulative patch
[0183] PHCO — 10576 REP sar(1) cumulative patch
[0184] PHCO — 8820 sar(1M) patch
[0185] The reposting notice can be viewed using qpc:
[0186] $ qpc 10576 Repost
[0187] PHCO — 10576:
[0188] Repost: 98/04/20
[0189] A problem was discovered with replacement patch PHCO — 14228. PHCO — 14228 breaks the Year 2000 compliance implemented in patch PHCO — 8820. PHCO — 10576 will be re-released until a replacement patch is available.
[0190] As indicated earlier, the patch tools work as well for upgrades, so they are general to updates. The invention has industrial applicability to both hardware and software manufacturers, as it allows them to organize and distribute their updates both internally and to customers in a manner that optimizes updates for performance and compatibility. Other variations upon and modifications to the described embodiments are provided for by the present invention, the scope of which is defined by the following claims.
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An update management system provides access to software updates (patches and upgrades) and to an update catalog server. The catalog server includes a chronology generator. When a request for an update family tree for a target update is received, the chronology generator accesses an index to find the database and record number for the target update. The record is retrieved, indicating updates superseded by the target update and updates superseding the target update. Records for the superseded and superseding updates are, in turn, retrieved. The process is iterated until there are no further superseding and no superseded updates indicated. The succession relations indicated in the retrieved records are arranged into a family tree for the target patch. The family tree can be used (along with dependency data) to help determine an update for a given workstation that optimizes performance and compatibility. Optionally, the family tree can be used to generate an update state list to assist in the optimization.
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FIELD OF THE INVENTION
The present invention relates to a method and apparatus for using less reliable memory devices for temporary storage of multibit digital data.
BACKGROUND OF THE INVENTION
It is often necessary to temporarily store multibit digital data during processing of that data. Memory devices are used for such storage. In general, it is imperative that the data 1 0 retrieved from such memory devices be an exact replica of the data previously stored. However, in some applications, while it is highly desirable that the retrieved data be a replica of the previously stored data, it is not imperative.
One example of such an application is the processing of audio data in digital form, such as in video camcorders, tapeless telephone answering machines or tapeless audio recorders. This application does not require the absolute fidelity which, for example, a computer storage device requires. In such devices, an analog audio signal is represented by a sequence of multibit digital samples, each having a binary value representing the value of the corresponding analog audio signal. Such samples may, for example, be produced by an analogtodigital converter coupled to an analog audio signal source, or by a digital CD player. During the processing of this audio signal, the series of digital samples representing the audio signal is stored in a memory device, and later retrieved for subsequent processing.
In the applications described above, which do not require absolute fidelity of retrieved data to the previously stored data, memory devices which are not perfect, termed audio read/write memory (ARAM) devices, may be used. These lessthanperfect memory devices are less expensive than perfect memory devices. Because some infidelity in the retrieved samples is permissible, the use of such memory devices will allow for less expensive audio equipment without a noticeable degradation in performance. Prior such systems provided no handling for errors caused by data storage and retrieval errors. However, this resulted in seriously degraded performance when an error occurred. It is desirable that some way of handling errors resulting from the use of such memory devices be provided.
SUMMARY OF THE INVENTION
In accordance with principles of the present invention, a method and apparatus detects and conceals errors in stored digital samples. A multibit digital input sample is received and an error detecting code corresponding to that input sample, and having a predetermined number of bits, is calculated. Then a multibit digital storage sample is generated by substituting the error detecting code for the predetermined number of bits of the input sample. The storage sample is then stored in a memory device. A previously stored sample is retrieved from the memory device and is analyzed to detect whether an error has occurred. If an error is detected, a substitute sample which conceals the error via some means, such as interpolation is produced for the retrieved sample, otherwise the retrieved sample is produced.
Apparatus incorporating this invention may use less than perfect memory devices, such as ARAMs, for storage of digital samples for which absolute fidelity is not required. This results in a lower costs, while not noticeably degrading the performance for such systems.
BRIEF DESCRIPTION OF THE DRAWING
In the drawing:
FIG. 1 is a block diagram of apparatus according to the present invention for writing data into a memory device;
FIG. 2 is a block diagram of apparatus according to the present invention for reading previously written data from the memory device;
FIG. 3 is a more detailed block diagram of a portion of the read apparatus illustrated in FIG. 2; and
FIG. 4 and FIG. 5 are waveform diagrams useful in understanding the operation of the portion of the read apparatus illustrated in FIG. 3.
DETAILED DESCRIPTION
FIG. 1 is a block diagram of apparatus according to the present invention for writing data into a memory device. In FIG. 1, a data source 10 generates, in a known manner, a stream of successive multibit digital samples, each consisting of a plurality of bits arranged in a known manner from a least significant bit (LSB) to a most significant bit (MSB). The digital samples are produced, successively, at an output terminal of the data source 10. The output terminal of the data source 10, with the exception of the LSB, is coupled to respective input terminals of an error detecting code (EDC) generator 30 and a memory device 20. An output terminal from the EDC generator 30 is supplied to the LSB input terminal of the memory device 20 input terminal, in place of the LSB from the digital data source.
The EDC generator 30 may be any one of known generators of one of more error detecting code bits, and in the illustrated embodiment is a parity generator 30. In general, the number of error detecting code bits generated by the EDC generator 30 are substituted for the same number of LSBs in the word from data source 10 before being stored in the memory device 20. The remainder of the application will refer to the parity generator 30 and single parity bit, but one skilled in the art will understand that any one of the known error detecting code generators, generating any number of error detecting code bits, may be used in its place.
In operation, the memory device 20 is a lessthanperfect memory device, and may include some memory locations which produce erroneous results when data is retrieved from those locations. To provide error detection for the memory device 20, without increasing the required memory capacity, the resolution of the digital data represented by the digital data stream is reduced (e.g. by one data bit), and an error detection code, (e.g. in the form of a parity bit), is substituted for that data bit. For example, for a 16 bit digital audio signal, the LSB is stripped from each sample, resulting in an audio signal having a resolution of 15 bits. As described above, for some audio applications, such as telephone answering machines, this loss of resolution is unnoticeable by a user.
The parity generator 30 generates, in a known manner, a parity bit for the full sized (16 bit) digital sample supplied to its input terminal (less any bits that will be discarded). In the illustrated embodiment, the parity bit is an odd parity bit, although an even parity bit may also be used. This parity bit is appended to the reduced resolution (15 bit) digital audio signal sample as its LSB. The nature of the parity bit is that it has the values logic `1` and logic `0` about equally. The DC offset resulting from appending this bit to a digital sample as the LSB, thus, is negligible, even during silent periods. In addition, the use of the parity bit as the LSB provides a desirable dithering function. This parity encoded digital sample is stored in the memory device 20 at locations controlled in a known manner by a memory controller (not shown).
FIG. 2 is a block diagram of apparatus according to the present invention for reading previously written data from the memory device 20. In FIG. 2, the memory device 20 is the same memory device illustrated in FIG. 1. An output terminal of the memory device 20 is coupled to respective input terminals of an error detector 60 and an error corrector 40. The error detector 60 corresponds to the error detecting code generator 30 (of FIG. 1) and may be any circuit which provides an indication of the integrity of the data encoded by the error detecting code generator 30. In the illustrated embodiment, the error detecting code generator is a parity generator, and the error detector is a parity check circuit 60. A multibit output terminal of the error corrector 40 produces a stream of successive errorcorrected multibit digital samples (represented by the thick signal line) in a manner described in more detail below, and is coupled to a corresponding input terminal of utilization circuitry 50. An output terminal of the error detector 60 is coupled to a control input terminal of the error corrector 40.
In operation, the memory device 20 retrieves data signal samples from locations in the memory device 20 controlled in a known manner by the memory controller (not shown). The retrieved samples may have bits which are not the same as those of the previously stored sample. The error detector 60 performs a data integrity check on the retrieved sample and generates an error signal when an error has been detected in the retrieved sample. This error signal is supplied to the error corrector 40, which performs a correction function, described in more detail below, in response to the error signal. The error corrector 40 produces a stream of successive multibit digital samples which either represent the originally stored data signal or reduce the noise introduced into the signal by errors in the memory device 20 (e.g. by linear interpolation between the last good data sample and the next good data sample). The error corrector 40 supplies that sample stream to the utilization circuitry 50. The combination of the error detector 60 and error corrector 40 provides a correction function in the event that a digital sample is retrieved from a defective location in the memory device 20. The utilization circuitry 50 processes the error corrected data stream. For example, in a tapeless sound recorder, the utilization circuitry may include a digitaltoanalog converter, audio amplifier and speaker.
FIG. 3 is a more detailed block diagram of the error corrector 40 illustrated in FIG. 2, and FIG. 4 and FIG. 5 are waveform diagrams useful in understanding the operation of the portion of that apparatus. In FIG. 3, thick signal lines represent signal paths carrying multibit digital signals, and thin signal lines represent signal paths carrying either single bit digital signals, or clock signals. In FIG. 3, an input terminal 48 is coupled to the output terminal of the memory 20 (of FIG. 2). Input terminal 48 is coupled to an input terminal of the parity check circuit 60 and a data input terminal of a first latch 41. An output terminal of the first latch 41 is coupled to a data input terminal of a second latch 42 and a first input terminal of an adder 43. An output terminal of the second latch 42 is coupled to a first data input terminal of a multiplexer 44 and a second input terminal of the adder 43. An output terminal of the adder 43 is coupled to a second data input terminal of the multiplexer 44 through a dividebytwo circuit 45. The combination of the adder 43 and dividebytwo circuit 45 forms an averaging circuit 46. An output terminal of the multiplexer 44 is coupled to an output terminal 49. The output terminal 49 is coupled to the input terminal of the utilization circuitry 50 (of FIG. 2).
The parity error output terminal of the parity check circuit 60 is coupled to an error input terminal E of a control circuit 47. A clock generator (not shown) is coupled to a clock input terminal C of the control circuit 47. A first strobe output terminal S 1 of the control circuit 47 is coupled to a control input terminal of the first latch 41; a second strobe output terminal S2 of the control circuit 47 is coupled to a control input terminal of the second latch 42, and a multiplexer control signal output terminal SEL of the control circuit 47 is coupled to a control input terminal of the multiplexer 44.
The operation of the apparatus illustrated in FIG. 3 will be explained in conjunction with the waveform diagrams illustrated in FIG. 4 and FIG. 5. In operation, a clock generator (not shown) produces a clock signal in synchronism with the digital data samples produced by the memory 20 in a known manner. Referring to FIG. 4, the sequence of samples is illustrated in the top line, DATA IN. The first illustrated sample, is S0, the next is SI, and so forth. The error signal at the error input terminal E of the control circuit 47 is illustrated on the second line, ERROR, of FIG. 4. When this signal is low, it indicates that no error has occurred in the corresponding sample, and if the signal is high, it indicates that a parity error has been detected by the parity check circuit 60.
The error signal for each sample is evaluated by the control circuit 47. When the error signal indicates that no error has occurred, the control circuit 47 provides a strobe signal, STROBE 1, illustrated on the third line of FIG. 4, to the first latch 41. At the falling edge of the first strobe signal, STROBE 1, the first latch 41 latches the signal from the input data input terminal 48, and supplies it to its output terminal in a known manner. The output from the first latch 41 is illustrated as the fourth line in FIG. 4.
In a similar manner, the control circuit 47 supplies a second strobe signal, STROBE 2, illustrated on the fifth line of FIG. 4, to the second latch 42. In response to the falling edge of the second strobe signal, STROBE 2, the second latch 42 latches the signal from the output terminal of the first latch 41, and supplies it to its output terminal in a known manner. The output from the second latch 42 is illustrated as the sixth line on FIG. 4.
In addition, the control circuit 47 also supplies the multiplexer control signal, SELECT, illustrated as the seventh line in FIG. 4, to the control input terminal of the multiplexer 44. When the multiplexer control signal, SELECT, is low, the multiplexer 44 is conditioned to pass the signal from the output terminal of the second latch 42 to the output terminal 49. When the multiplexer control signal, SELECT, is high, the multiplexer 44 is conditioned to pass the signal from the output terminal of the averaging circuit 46 to the output terminal 49.
So long as no parity errors are detected by the parity check circuit 60, the control circuit 47 continually supplies the first and second strobe signals (STROBE 1 and STROBE 2) to the first and second latches, 41 and 42, respectively, and the multiplexer control signal is maintained low, conditioning the multiplexer 44 to pass the signal from the second latch 42 to the output terminal 49. In this operating mode, the first and second latches, 41 and 42, act as pipeline registers and the input samples, DATA IN, are passed through the error handler 40 delayed, but without any changes.
If, however, the error signal, ERROR, at the error input terminal E of the control circuit 47 indicates that a parity error has occurred, the sample currently at the input terminal 48 is invalid. In this case, no strobe signal STROBE 1 is supplied to the first latch 41, and it continues to hold the most recent good sample. However, the second strobe signal, STROBE 2, is still supplied to the second latch, regardless of the state of the error signal ERROR from the control circuit 47. In addition, the multiplexer control signal SELECT is maintained low to condition the multiplexer 44 to pass the signal from the second latch 42 to the output terminal 49.
Referring to FIG. 4, the error signal ERROR is low during the sample time for sample S0, 401, indicating that sample S0 is a good sample. In response, the trailing edge 402 of the first strobe signal, STROBE 1, latches the good sample S0 from the input terminal 48 (DATA INPUT) into the first latch 41, and it appears at its output terminal, as illustrated in the waveform LATCH 41. At the same time, the trailing edge 403 of the second strobe signal STROBE 2 latches the previous symbol (unlabeled) from the first latch 41 into the second latch 42 and it appears at its output terminal as illustrated in waveform LATCH 42. Also, the multiplexer control signal SELECT is low at that sample period 408, and the output signal from the second latch 42 is supplied to the utilization circuitry 50.
Sample S1, however, is found by the parity check circuit 60 to have bad parity, and the error signal, ERROR, is made high for the duration of sample SI, at 404, to indicate this. While the error signal, ERROR, is high, the control circuit 47 does not generate a first strobe signal STROBE 1. Thus, there is no strobe signal at 410 in the sample period after the trailing edge 402. This prevents the bad sample S 1 from being latched into the first latch 41. Instead, the previous good sample, S0, remains at the output of the first latch 41.
The second latch 42, however, continues to receive the second strobe signal, STROBE 2, and it latches the signal from the output terminal of the first latch 41 to its output terminal in the normal fashion. For example, the trailing edge 406 of the second strobe signal, STROBE 2 causes the second latch 42 to latch the signal S0 which remained at the output terminal of the first latch 41 and supply it to its output terminal, LATCH 42.
If a single isolated sample is bad, that is if the next sample after a bad sample is a good sample, as indicated at 412 of the parity error signal ERROR from the parity check circuit 60, then both the first latch 41 and the second latch 42, again receive strobe signals in the normal manner. For example, in FIG. 4, after the bad sample, SI, the trailing edge 414 of the first strobe signal, STROBE 1, causes the first latch 41 to latch the next succeeding good sample S2 at the data input terminal 48 and supply it to its output terminal LATCH 41, while the trailing edge 416 of the second strobe signal STROBE 2 causes the second latch 42 latch the signal S0 and supply it to its output terminal LATCH 42. The output signal from the first latch 41 is the most recent good sample S2, and the output signal from the second latch 42 is the previous good signal S0. As described above, the intervening bad sample was not latched. At this time, the averaging circuit 46 produces a signal which is the average of the value of the two signals, S0 and S2, latched by the first and second latches, 41 and 42, respectively. When the first good sample after a bad sample has been latched into the first latch 41, the multiplexer control signal supplied to the multiplexer 44 for this sample period, at 418, conditions the multiplexer 44 to couple the signal from the averaging circuit 46 to the output terminal 49. In this manner, if an isolated sample is bad, it is replaced with a sample having the average of the two good samples surrounding it.
FIG. 5 is a waveform diagram illustrating the operation of the circuit illustrated in FIG. 3 responding to different input signal conditions. In FIG. 5, two samples in a row, S1 and S2, have parity errors detected. The operation of the circuit of FIG. 3, up to the reception of the second bad sample S2, is similar to the operation of that circuit illustrated in FIG. 4 and that operation is not described in detail below. Time 502 of the parity error signal ERROR, indicates that the sample S2 also contains a parity error. Because sample S2 is also bad, then, as before, no first strobe signal STROBE 1 is supplied to the first latch 41. Thus, at 504 of the first strobe signal STROBE 1, no strobe signal occurs, and the previous good sample S0 remains in the first latch 41. However, at 506 of the second strobe signal STROBE 2, the second latch 42 relatches the last good sample S0 from the first latch 41, and supplies it to its output terminal LATCH 42. At this time, both the first latch 41 and the second latch 42 contain the last good sample S0. At time 510, the multiplexer control signal SELECT is maintained low, and the multiplexer 44 is conditioned to continue to pass the signal from the second latch 42 to the output terminal 44. This will continue so long as bad samples are received at the input terminal 48.
At time 508, the parity error signal ERROR is low, indicating that the next sample, S3 does not contain a parity error. As described above, in response, the trailing edge 512 of the first strobe signal STROBE 1 latches the most recent good sample S3 into latch 41, which passes it to its output terminal LATCH 41. At this time, the first latch 41 contains the most recent good sample S3, and the second latch 42 contains the last good sample S0. Also at this time, the averaging circuit 46 produces a signal which is the average of those two samples. As before, when a first good sample is latched into the first latch 41 after a bad sample had been previously received, the multiplexer control signal SELECT, at 514, is made high, which conditions the multiplexer 44 to couple the signal from the averaging circuit 46 to the output terminal 49. In this manner, if a series of bad samples is received, the last good sample is repeated at the output terminal, until another good sample is received. Then, one sample containing the average of the last received good sample and the newly received good sample is produced before the error corrector 40 resumes its normal operational mode.
The present invention has been described with reference to an embodiment fabricated from discrete components.
One skilled in the art will understand that the invention may also be practiced by the use of a microprocessor programmed to access a memory device 20 and execute a program to process data samples as described above.
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A method and apparatus is disclosed for detecting and concealing errors in stored digital samples. A multibit digital input sample is received and an error detecting code, corresponding to that input sample is calculated. Then a multibit digital storage sample is generated by substituting the error detecting code for the same number of least significant bits of the input sample. The storage sample is then stored in a memory device. A previously stored sample is retrieved from the memory device and is analyzed to detect whether an error has occurred. If an error is analyzed to detected, a substitute sample produced for the retrieved sample, otherwise the retrieved sample is produced.
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BACKGROUND OF THE INVENTION
The present invention relates generally to a device for handling material, and more particularly relates to a feed system for feeding fasteners into a fastener installation apparatus.
Fasteners, such as pierce nuts disclosed in U.S. Pat. No. 2,707,322, are widely used in mass production applications such as in the automotive industry. In many instances, including mass production applications, it is advantageous to "string" (or join) fasteners together in a common orientation prior to feeding them into the installation apparatus. One advantage in joining fasteners to form a strip of fasteners is that it typically simplifies the design of the fastener feed system. U.S. Pat. No. 3,845,860 discloses a method for joining a plurality of fasteners into a strip of fasteners whereby each fastener in the strip of fasteners has a common orientation.
Although feeding an installation device with a strip of fasteners simplifies the design of the fastener feed mechanism, the strip of fasteners eventually terminates and, in order to keep the installation apparatus operating without interruption, a smooth transition must take place between the end of one fastener strip and the beginning of the next fastener strip. Prior art attempts to provide automatic transfer between strips of fasteners have proven inadequate to meet the demands of mass production applications.
Accordingly, it is an object of this invention to provide a feed mechanism capable of continuously feeding a strip of fasteners into an installation apparatus and also capable of continuous operation between first and second sets of fastener strips wherein the sets of fastener strips are not joined.
SUMMARY OF THE INVENTION
The present invention includes an apparatus for moving material along a chute. The apparatus includes first and second pawls each including a finger portion for engaging the material. The pawls are joined together by virtue of a rod extending there between. The pawls are pivotally connected to the rod and each enjoy pivotal movement independently of one another. A wheel, or the like, is attached to the rod for reciprocating the pawls relative to the chute. The finger portions of the pawls engage the material when it is located in the chute and the fingers move the material in a first direction along the chute when the pawls move in the first direction during one-half of their reciprocation stroke. During the remaining half of the reciprocation stroke the fingers of each pawl skip across the top of the material resulting in no movement of said material within the chute.
In a preferred embodiment a feed bias spring is provided for biasing the rod along the first direction and pawl biasing springs are included with each pawl for urging the respectively associated pawl against the material.
In a second aspect, the present application sets forth an apparatus for moving material, including first and second pawls each including a finger portion for engaging the material to be moved. The first and second pawls are pivotally connected to opposed ends of a connecting rod. The rod preferably includes a roller which is rotatingly coupled to the rod. A chute is provided for guiding the material wherein the first and second pawls are slidingly coupled to the chute. A drive means is utilized for reciprocating and for engaging the roller and causing the first and second pawls to reciprocate along the chute. When the first and second pawls move in a first direction during one-half of their reciprocation stroke, the finger portion of each pawl engages the material located in the chute and moves the material through the chute. During the remaining half of the reciprocation stroke, the pawls skip across the material resulting in no movement of material. Preferably, the drive means reciprocates generally transversely to the reciprocation of the first and second pawls.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross sectional side view of the feed apparatus of the present invention feeding a strip of fasteners from a reel of fasteners into a continuous installation head.
FIG. 2 is an isometric view of a strip of fasteners, namely pierce nuts.
FIG. 3 is an isometric view of a fastener installed in a panel.
FIG. 4 is a cross sectional view of the feed apparatus of the present invention shown feeding a strip of fasteners into a continuous installation head wherein the strip of fasteners is near its end.
FIG. 5 is a cross sectional view of the feed apparatus of the present invention wherein the beginning of a second strip of fasteners is abutted to the end of the first strip of fasteners.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Now referring to FIG. 1, feed mechanism 10 is used to feed fastener strip 14 into installation head 22 of installation apparatus 12. Installation apparatus 12 separates (or shears) one of the fasteners 14' from strip 14 and joins it to panel 18. The method of joining fastener 14' to panel 18 is generally accomplished by piercing fastener 14' through panel 18 and, thereafter, deforming a portion of fastener 14' and/or panel 18, thereby causing it to engage panel 18 in a way which securely joins fastener 14' to panel 18. FIG. 3 shows a completed installation of fastener 14' in panel 18. U.S. Pat. Nos. 2,707,322 and 3,648,747 both disclose methods of installing fasteners, namely pierce nuts, in metal panels.
In mass production applications, installation apparatus 12 is normally located in a die press (not shown) capable of generating several tons of force. Installation apparatus 12 reciprocates vertically 24. On the downward stroke of reciprocation 24, punch 26 separates fastener 14' from fastener strip 14 and forces it through panel 18. Die 20 receives fastener 14' and deforms fastener 14' in a way which causes fastener 14' to positively engage and retain panel 18. On the upward stroke, feed mechanism 10 places the next fastener 14" beneath punch 26 thereby readying installation apparatus 22 for the next fastener installation into panel 18.
Fastener strip 14 is typically supplied to feed mechanism 10 by way of reel 16. Fastener strip 14 is comprised of a plurality of individual fasteners, each of which are joined together in a common orientation. FIG. 2 discloses one preferred method of joining a plurality of fasteners to form a fastener strip. In this preferred embodiment, individual fasteners are joined by one or more wires 28. U.S. Pat. No. 3,845,860 discloses a method and apparatus for forming a strip of fasteners by using a wire carrier. Other techniques for generating strips of fasteners may work equally well.
Feed mechanism 10 is comprised of forward pawl assembly 30 and rearward pawl assembly 32. Forward pawl assembly 30 is comprised of housing 34 which is fixed relative to chute 36. Forward pawl 40 is connected to rearward pawl assembly 32 by way of shaft 42. Pawl 40 is connected to plate 44 by way of pivot pin 46. Thus, forward pawl 40 is pivotally connected to plate 44. Roller wheel 48 is connected to plate 44 and freely rotates about axis 50.
When installation apparatus 12 reciprocates 24 in the manner which has already been described, ramped surface 54 of drive block 52 engages roller wheel 48 and causes forward pawl 40 to horizontally reciprocate 56. Because shaft 42 connects plate 44 and rearward pawl assembly 32, rearward pawl assembly reciprocates 56 in synchronism with forward pawl assembly 30. Feed bias spring 58 biases wheel or roller 48 against ramp surface 54. Accordingly, the upward movement of installation apparatus 12 causes forward and rearward pawl assemblies 30, 32 to move toward punch 26 and the downward movement of installation apparatus 12 causes forward and rearward pawl assemblies 30, 32 to move away from punch 26. Rearward pawl assembly 32 is loosely coupled to chute 36 thereby enabling it to freely, horizontally reciprocate as demanded by shaft 42.
Although forward pawl 40 is pivotally connected to plate 44 by way of pivot pin 46, its pivotal motion is limited, in the counter-clockwise direction, by the presence of stop block 60. Forward pawl 40 is biased against stop block 60 by way of forward pawl bias spring 62. Forward pawl 40 includes, at its lower end, finger 64. Finger 64 is appropriately sized to engage a portion (such as an aperture, etc.) of a fastener in fastener strip 14.
As installation apparatus 12 reciprocates 24, this reciprocating motion drives feed mechanism 10 such that forward pawl assembly 30 shuttles (horizontally forward and backward) in synchronism with the vertical reciprocations of installation apparatus 12. During the first half of its reciprocal movement, forward pawl 40 moves away from punch 26, compressing spring 62 and allowing finger 64 to skip along top of a fastener in fastener strip 14. This skipping movement does not exert enough force to move strip 14. During the second half of its reciprocal movement, when assembly 30 moves towards punch 26, finger 64 engages a portion of one of the fasteners in fastener strip 14 and the urging of feed bias spring 58 acting through finger 64 moves fastener strip 14 toward punch 26. Thus, feed mechanism 10 converts reciprocal vertical 24 motion into a unilateral, horizontal force which moves fastener strip 14 from reel 16 into installation apparatus 12.
Rearward pawl assembly 32 is comprised of rearward pawl 66, which is pivotally connected to rearward pawl housing 72 by way of pivot pin 68. The pivotal movement of rearward pawl 66 is limited in the same manner as that described for forward pawl 40 in that its counter-clockwise movement is limited by surface 74 of rearward pawl housing 72. Rearward pawl bias spring 70 operates to allow finger 76 of rearward pawl 66 to skip across fastener strip 14 when rearward pawl 66 moves away from punch 26 and causes finger 76 to engage a fastener of fastener strip 14 when rearward pawl 66 moves towards punch 26. Thus, as will now be understood, that the operation of rearward pawl assembly 32 is identical to, and in horizontal synchronism with, forward pawl assembly 30.
Now referring to FIG. 4 of the drawings, in conventional single pawl feed systems, once the end 78 of fastener strip 14 progresses past finger 64 of forward pawl 40, feed mechanism 10 can no longer push fastener strip 14 into installation head 22. Thus, in conventional single pawl feed systems, the operator must stop the operation of the machine, feed a new fastener strip 14 into chute 36, and then commence operation. In mass production environments, the starting and stopping of an operation to load the next strip of fasteners is a highly inefficient use of time. However, in addition to these drawbacks, another disadvantage is associated with single pawl feeders. This undesirable condition is known as the "half nut" condition. This condition exists when end 78 of strip 14 is just beyond forward pawl 40. Under these conditions, pawl 40 will push strip 14 towards punch 26, however, because there is, in effect, a fastener missing (no new fastener strip has been fed in yet), the existing fastener strip 14 is advanced approximately one half its normal distance. Thus, one can easily understand from FIG. 4, that once fastener 14' is removed from strip 14, finger 64 will only advance strip 14 approximately one-half of its normal travel by virtue of not having a fastener to properly engage. Under these conditions, punch 26 will simply shear a partially exposed nut from strip 14 thereby possibly damaging installation head 22 and panel 18. Thus, it will now be shown that the undesirable side effects associated with a single pawl feed system are overcome by the dual feed pawl system of the present invention.
Now referring to FIG. 5, whenever the last fastener 78 in a strip of fasteners 14 falls between forward pawl 40 and rearward pawl 66, the feed mechanism of the present invention allows subsequent fastener strip 15 to be fed into chute 36 and forced past rearward pawl 66. In the manner which has already been described, rearward pawl 66 will pivot clockwise thereby riding over fastener strip 15 as fastener strip 15 is pushed through chute 36. Fastener strip 15 is pushed through chute 36 until first nut 14'" abuts last nut 78. Once this abutting relationship is established, the synchronous operation of forward pawl 40 and rearward pawl 66 guarantee that the half nut condition will not take place and the operation of installation apparatus 12 will continue, uninterrupted, from fastener strip 14 to subsequent fastener strip 15. An "electric eye," proximity sensors, or any other conventional means may be employed to sense end 78 of fastener strip 14 and indicate the sensed condition to the machine operator. This indication will give the operator sufficient time to remove empty reel 16 and load and thread a full reel. The placement of the sensor will be a function of the lead time needed to swap reels. Some of the factors to consider when determining necessary lead time are the speed at which the fasteners are being installed, the skill of the operator, and the difficulty associated with swapping reels.
Having described the preferred embodiments of the feed mechanism of the present invention, it will be understood that various modifications or additions may be made to the preferred embodiment chosen here to illustrate the present invention without departing from the spirit of the present invention. For example, even though the feed mechanism has been shown feeding nut type fasteners, it is contemplated that any type of continuously joined fasteners can be fed by the feed mechanism of the present invention. Also, the feed mechanism has been shown for use in conjunction with a fastener installation head. This approach was taken primarily because feed mechanisms of this type are commonly used in conjunction with fastener installation heads; however, feed mechanisms may be used in conjunction with any type of material handling system, and accordingly, the feed mechanism of the present invention is not solely limited to feeding materials into an installation head for installation onto a panel.
Accordingly, it is to be understood that the subject matter sought to be afforded protection thereby shall be deemed to extend to the subject matter defined in the appended claims, including all fair equivalents thereof.
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A dual pawl, feed mechanism for feeding a strip of fasteners into an installation apparatus. The mechanism includes first and second pawls which are connected together and reciprocate in horizontal synchronism. The dual pawls enable a second strip of fasteners to be loaded into a chute before the first strip of fasteners is exhausted. This permits uninterrupted operation of the fastener installation apparatus irrespective of the transition between strips of fasteners. The dual feed pawl mechanism also prevents a partial feed condition from taking place.
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BACKGROUND OF THE INVENTION
The present invention relates to an apparatus for forming a flattened sample flow for passing a sample (liquid specimen) containing particle components such as blood and urine in a wide, thin, flat flow. The apparatus of the present invention is preferably used in an apparatus for analyzing particle images by emitting a strobe light to the flattened sample flow and taking still images of particle components.
The apparatus for taking images of particle components passed in a flat flow and analyzing particles by image processing is disclosed in Japanese Laid-open Patent Sho. 57-500995 or the U.S. Pat. No. 4,338,024. The flow cell possesses a large aspect ratio passage (ratio of length to width, more than scores of times) in the measuring region, forms a flat sheath flow in the passage, and takes the still images of its sample flat flow by a video camera. The passage dimensions in the imaging region is disclosed as being 100 μm in width and 5000 μm in length (the aspect ratio being 50 times). The sheath flow, meanwhile, refers to a flow having the circumference of a suspension of particles covered with a laminar sheath liquid in order to pass the particles by arranging them in one row precisely in the central part of the liquid flow.
On the other hand, the Japanese Laid-open Utility Model Hei. 3-44626 discloses a nozzle divided into plural nozzle openings along the flattening direction with the front end flattened, and a nozzle having a flat discharge opening for use in the cleanliness measurement of a cleanroom used in the manufacture of semiconductors or the like. Certainly, these nozzles are intended to flatten the sample flow, but sheath flow is not used, and they are merely intended to pass a large volume of liquid specimen. With these nozzles alone, the flat flow having a sufficient flatness as required in the present invention (about 10 μm ×900 μm) is not realized.
In U.S. Pat. No. 4,988,619, fins are disposed flatly across the flow chamber, and cylindrical rods are disposed across the flow chamber. These are, however, intended to enhance the orientation (aligning the direction) of flat particles in the flow cytometry, and it is not possible, as in the cases above, to realize the flatness required in the present invention (about 10 μm×900 μm).
In conventional flow cells disclosed in Japanese Laid-open Patent Sho. 57-500995 and U.S. Pat. No. 4,338,024, the thickness of the passage is about the size of the particles to be analyzed, and the dimensions are also required to be precise. Accordingly, it was difficult to manufacture and was expensive. Also because of the thin thickness, they were easily broken and hard to handle.
In the ordinary flow cytometer, the flow cell with an aspect ratio of the passage of about 1 is used. Using such a flow cell, the above problems are avoided, but flat sample flow is not formed in that state. Besides, in the apparatus disclosed in Japanese Laid-open Utility Model Hei. 3-44626 or U.S. Pat. No. 4,988,619, sufficient flat flow cannot be formed.
In the Flow Cytometry Handbook, Science Forum (1984), pp. 399-400, the force acting on the sample flow is mentioned. FIG. 1 is a diagram reprinted from this publication, showing a plan view of the flow cell part as seen from the flow direction. Comparing the, h, and, v, directions, the force fh in the, h, direction having a larger throttling ratio acts more than the force fv in the, v, direction having a smaller throttling ratio. This is used for arranging the direction of cells in the sample in a specific direction, and it is insufficient for forming a flat sample flow. Meanwhile, supposing the forces acting on the sample flow to be fh, fv, they are expressed as fh:fv= A/a:B/b, with the relation A/a>B/b.
OBJECT AND SUMMARY OF THE INVENTION
It is hence an object of the present invention to present an apparatus capable of forming a flattened sample flow by using a flow cell with the aspect ratio of flow being passage one to several times.
To achieve the above object, in the flow cell lead-in passage, the width of one side of the passage is narrowed, and communicates with the measurement passage. Then the discharge port of the sample nozzle is flattened, or small discharge ports are arranged horizontally in one row. Furthermore, the decreasing width dimension in the lead-in passage and the narrowing width dimension of the sample nozzle discharge are matched, that is, the decreasing width dimension in the lead-in passage and the diameter dimension when the discharge port is flat, or the vertical direction (the direction orthogonal to the arranging direction) when the discharge ports are arranged horizontally in one direction are matched.
An apparatus for forming flattened sample flow for analyzing particles of the present invention comprises:
a flow cell having a gradually narrowed lead-in passage, a narrow measuring passage contiguous to the lead-in passage, a sheath liquid feed port disposed in the lead-in passage, and a discharge port disposed at the downstream side of the measuring passage, and
a sample nozzle for discharging sample disposed in the lead-in passage of the flow cell so that the front end may be directed to the measuring passage, wherein the cross section of the measuring passage of the flow cell is rectangular with a side ratio of one to several times,
only the width of one direction of the passage is gradually narrowed in the lead-in passage of the flow cell,
a discharge port at the front end of the sample nozzle has an open flat configuration, and
the sample nozzle is disposed so that the shorter dimension of the discharge port extends in the same direction as the decreasing dimension of the lead-in passage.
In this case, it is desirable that the discharge port of the sample nozzle may have a broader width in the end portion than the width of the central portion. Moreover, instead of the flat shape of the discharge port of the sample nozzle a sample nozzle may be used, which has a plurality of small discharge ports arranged horizontally in one row, and the sample nozzle may be disposed so that the direction of the small discharge ports may be orthogonal to the decreasing dimension of the lead-in passage.
In this case, as an example, there is only one sample flow inlet at the other end of the sample nozzle, and it is divided into plural small passages inside the sample nozzle, and the small discharge ports are arranged in one row.
In this case, the number of small discharge ports of the sample nozzle is an even number, and it is desired to disposed the small discharge ports at symmetrical positions centered around the sample nozzle.
The diameter of the small discharge ports disposed at the end portion is desired to be larger than the diameter of the small discharge ports disposed in the central portion.
In the lead-in passage, since only one side is narrowed in width, the sheath liquid flows only in that direction, and a large force acts toward the inside of the passage, and in the direction in which the width is, a force does not act. That is, the sample throttling (narrowing down) action occurs only in one direction.
The discharge port of the sample nozzle is not circular as in the prior art, has is a flattened circular form, that is, an approximately elliptical form. Accordingly, the sample liquid discharge from the nozzle is formed into an extremely flat sample flow by the synergistic action of the two (the sample throttling action in the one direction only and the flat flow discharged from the nozzle), even in the measuring passage the aspect ratio of which is one to several times. Also in the case of a sample liquid discharged from plural small discharge ports of the sample nozzle, an extremely flat sample flow may be formed.
To further enhance the flatness of the sample flow, the discharge port of the sample nozzle is, for example, flat (approximately elliptical), or small discharge ports may be horizontally arranged in one row. In such a case, the discharge port is arranged so that the longitudinal direction thereof or the direction of the small discharge ports may be identical with the horizontal projecting direction of the sheath liquid dividing means.
As other means, moreover, a sample nozzle is disposed across the lead-in passage. And at the measuring passage side of the sample nozzle, that is, on the downstream side surface, plural small discharge ports are arranged in one row along the axial direction of the nozzle, and at the upstream side of the sample nozzle, dividing means are disposed for dividing the sheath liquid in the same direction as the axial direction of the sample nozzle.
Another apparatus for forming flattened sample flow for analyzing particles of the present invention comprises:
a flow cell having a gradually narrowed lead-in passage a narrow measuring passage contiguous to the lead-in passage, a sheath liquid feed port disposed in the lead-in passage, and a discharge port disposed at the downstream side of the measuring passage, and
a sample nozzle for discharging sample disposed in the lead-in passage of the flow cell so that the front end may be directed to the measuring passage, wherein
the cross section of the measuring passage of the flow cell is rectangular with a side ratio of one to several times,
sheath liquid dividing means for dividing the sheath liquid symmetrically into two flows is disposed in contact with the sample nozzle, and
the discharge port of the sample nozzle is positioned in the sheath liquid converging (confluencing) region at the downstream side of the sheath liquid dividing means.
In this case, using the sample nozzle the front end discharge port of which has a flat opening, it is desired to dispose the sample nozzle so that the longitudinal direction of the discharge port and the lateral projecting direction of the sheath liquid dividing means may be identical.
Furthermore, it is desirable to have the discharge port of the sample nozzle broader in width at its end portion than in its central portion.
Moreover, instead of the sample nozzle with the flat shaped discharge port, using a sample nozzle having small discharge ports disposed horizontally in a row, the sample nozzle may be disposed so that the arranged direction of the small discharge port and the lateral projecting direction of the sheath liquid dividing means may coincide.
As an example of this case, there is one sample flow inlet at the other end of the sample nozzle, and it is branched into plural small passages inside the sample nozzle, and the small discharge ports are arranged in a row.
In this case, using an even number of small discharge ports of the sample nozzle, it is desirable to have the small discharge ports at symmetrical positions centered around the sample nozzle.
Furthermore it is desirable to have the diameter of the small discharge ports disposed at the end portion greater than the diameter of the small discharge ports disposed in the central portion.
Another apparatus for forming a flattened sample flow for analyzing particles of the invention comprises:
a flow cell having a gradually narrowed lead-in passage, a narrow measuring passage contiguous to the lead-in passage, a sheath liquid feed port disposed in the lead-in passage, and a discharge port disposed at the downstream side of the measuring passage, and
a sample nozzle for discharging sample disposed in the lead-in passage of the flow cell so that the front end may be directed to the measuring passage, wherein
the cross section of the measuring passage of the flow cell is rectangular with a side ratio of one to several times,
a sample nozzle is disposed across the flow of the sheath liquid in the lead-in passage,
a plurality of small discharge ports are disposed horizontally in a row in the sample nozzle so as to open toward the measuring passage,
sheath liquid dividing means disposed at the upstream side of the small discharge ports of the sample nozzle in contact with the sample nozzle so as to divide the sheath liquid symmetrically into two flows, and
the sheath liquid dividing means is disposed so that the lateral projecting direction of the sheath liquid dividing means and the axial direction of the sample nozzle may coincide.
In this case, instead of disposing a plurality of small discharge ports in the sample nozzle, a flat (slit) discharge port may be disposed in the sample nozzle.
The sheath liquid is divided into two flows by the sheath liquid dividing means projecting in the lateral direction. When the sheath liquid flows converge (confluence), the sample liquid discharge from the discharge port of the sample nozzle is sandwiched, so that a flat sample flow is formed.
By flattening the discharge port of the sample nozzle or disposing a plurality of small discharge ports horizontally in one row, a further preferred flat sample flow is formed.
Moreover, when disposing the sample nozzle across the lead-in passage, first the sample liquid is led into the nozzle from one end of the nozzle, and is discharged from the other end of the nozzle. The plural small discharge ports or flat discharge ports are disposed from one end of the sample nozzle to the other end, and therefore the supplied sample liquid is discharged from the plural small discharge ports or flat discharge ports, and a preferred flat sample flow is formed together with the action of the sheath liquid dividing means.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an explanatory plan view showing the force acting on the sample flow in a conventional flow cell.
FIG. 2 is a front sectional view showing an embodiment of an apparatus for forming a flattened sample flow for analyzing particles according to the present invention.
FIG. 3 is a right sectional view of the apparatus shown in FIG. 2.
FIG. 4 is a plan view of the apparatus shown in FIG. 2.
FIG. 5 is a perspective view showing an example of sample nozzle used in the apparatus of the present invention.
FIG. 6 is a sectional view showing a cut off section along the longitudinal direction of a nearly elliptical discharge port in the nozzle shown in FIG. 5.
FIG. 7 is a front view of the the sample nozzle shown in FIG. 6 rotated by 90 degrees.
FIG. 8 is a right side view of the nozzle shown in FIG. 6.
FIG. 9 is a left side view of the nozzle shown in FIG. 6.
FIG. 10 is an explanatory diagram showing another example of a discharge port of the nozzle shown in FIG. 9.
FIG. 11 is a perspective view showing another example of a sample nozzle used in the apparatus of the present invention.
FIG. 12 is a sectional view showing a cut off along the arranging direction of plural small discharge ports in the nozzle shown in FIG. 11.
FIG. 13 is a partially cut-away front view of the nozzle shown in FIG. 12 rotated by 90 degrees.
FIG. 14 is a right side view of the nozzle shown in FIG. 12.
FIG. 15 is a left side view of the nozzle shown in FIG. 12.
FIG. 16 is a front sectional view showing another embodiment of an apparatus for forming a flattened sample flow for analyzing particles of the present invention.
FIG. 17 is a right side sectional view of the apparatus shown in FIG. 16.
FIG. 18 is a perspective view around the apparatus shown in FIG. 16.
FIG. 19 is an explanatory diagram showing a flow velocity distribution in a conventional sheath flow portion without sheath liquid dividing means (the sheath flow stabilizing portion in the apparatus of the present invention).
FIG. 20 is an explanatory diagram showing the flow velocity distribution in the sheath liquid dividing portion in the apparatus of the present invention.
FIG. 21 is an explanatory diagram showing the flow velocity distribution in the sheath liquid converging portion in the apparatus of the invention.
FIG. 22 is an explanatory diagram showing the direction of force applied by the sheath flow to the sample flow in the conventional flow cell, being a plan view as seen from the flow direction of the sheath flow.
FIG. 23 is an explanatory diagram showing the direction of force applied by the sheath flow to the sample flow in the flow cell of the present invention, being a plan view as seen from the flow direction of the sheath flow.
FIG. 24 is a front sectional view showing a further different embodiment of the apparatus of the present invention.
FIG. 25 is a right sectional view of the apparatus shown in FIG. 24.
FIG. 26 is a perspective view around the apparatus shown in FIG. 24.
FIG. 27 is a magnified view showing an example of the sample nozzle shown in FIG. 24.
FIG. 28 is a bottom view of the sample nozzle shown in FIG. 27.
FIG. 29 is a sectional view along the line D--D in FIG. 27.
FIG. 30 is a magnified view showing another example of the sample nozzle shown in FIG. 24.
FIG. 31 is a bottom view of the sample nozzle shown in FIG. 30.
FIG. 32 is an a sectional view along the line E--E in FIG. 30.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, some of the preferred embodiments of the present invention are described in detail below.
As shown in FIG. 2 to FIG. 9, an apparatus for forming a flattened sample flow for analyzing particles comprises:
a flow cell 10 having a gradually narrowing lead-in passage 14, a narrow measuring passage 16 contiguous to the lead-in passage 14, a sheath liquid feed port 18 disposed to intersect the lead-in passage 14, and a discharge port 20 disposed at the downstream side of the measuring passage 16, and
a sample nozzle 12 for discharging sample disposed in the lead-in passage 14 such that the front end of the sample nozzle is directed to the measuring passage 16, wherein
the cross section of the measuring passage 16 is rectangular with a side ratio of one to several times,
the width of only one direction of the lead in passage 14 is gradually narrowed
a discharge port 22 at the front end of the sample nozzle 12 has a flat opening, and
the sample nozzle 12 is disposed so that the shorter length of the discharge port 22 may extend in the same direction as the decreasing direction of the lead-in passage 14.
In the case, as shown in FIG. 10, the construction is such that the discharge port 22 of the sample nozzle 12 may have a broader width in the end portion 28 than the width at the central portion. Moreover, instead of the sample nozzle with a flat shaped discharge part, a sample nozzle 12a may be used, which has a plurality of small discharge ports 30 arranged horizontally in one row, and the sample nozzle 12a may be disposed so that the arranged direction of the small discharge ports 30 may be orthogonal to the decreasing direction of the lead-in passage 14.
In this case, as an example, as shown in FIG. 12 to FIG. 15, there is only one sample flow inlet 26 at the other end of the sample nozzle, and it is divided into plural small passages 36 inside the sample nozzle, with the small discharge ports 30 are arranged in one row.
In the case shown in FIG. 12 to FIG. 15, the number of small discharge ports 30 of the sample nozzle is an even number, and it is desired to disposed the small discharge ports 30 centered symmetrically around the sample nozzle.
The diameter of the small discharge ports disposed at the end portion is desired to be larger than the diameter of the small discharge ports disposed in the central portion.
Since in the lead-in passage 14, the width of one side is narrowed, the sheath liquid flows only in that direction, and a large force acts toward the inside, and in the direction in which the width is, a not changed in width, force does not act. That is, the sample throttling (narrowing down) action occurs only in one direction.
The discharge port 22 of the sample nozzle 12 is not circular as in the prior art, but is in a flattened circular form, that is, an approximately elliptical form. Accordingly, the sample liquid discharge from the nozzle 12 is formed into an extremely flat sample flow by the synergistic action of the two (the sample throttling action in one direction only and the flat flow discharged from the nozzle), even in the measuring passage 16 the aspect ratio of which is one to several times. Also in the case of a sample liquid discharged from plural small discharge ports 30 of the sample nozzle 12a, an extremely flat sample flow may be formed.
As shown in FIG. 16 to FIG. 18, an apparatus for forming flattened sample flow for analyzing particles comprises:
a flow cell 10 having a gradually narrowing lead-in passage 14, a narrow measuring passage 16 contiguous to the lead-in passage 14, a sheath liquid feed port 18 disposed in the lead-in passage 14, and a discharge port 20 disposed at the downstream side of the measuring passage 16, and
a sample nozzle 12 for discharging sample is disposed in the lead-in passage 14 of the flow cell so its front end may be directed to the measuring passage 16, wherein
the cross section of the measuring passage 16 of the flow cell 10 is rectangular with a side ratio of one to several times,
sheath liquid dividing means 13 for dividing the sheath liquid symmetrically into two flows is disposed in contact with the sample nozzle 12, and
the discharge port of the sample nozzle 12 is positioned in the sheath liquid converging (confluencing) region at the downstream side of the sheath liquid dividing means 13.
In this case, as shown in FIG. 5 to FIG. 9, using the sample nozzle 12 the front end discharge port 22 of which is a flat opening, it is desired to dispose the sample nozzle 12 so that the longitudinal direction of the discharge port 22 and the lateral projecting direction of the sheath liquid dividing means 13 may be identical.
Moreover, instead of the sample nozzle the shaped of the discharge port is flat, as shown in FIG. 11, using a sample nozzle 12a having small discharge ports 30 disposed horizontally in a row, the sample nozzle 12a may be disposed so that the arranging direction of the small discharge ports 30 and the lateral projecting direction of the sheath liquid dividing means 13 may coincide.
As an example of this case, as shown in FIG. 12 to FIG. 15, there is one sample flow inlet 26 at the other end of the sample nozzle, and it is branched into plural small passages 36 inside the sample nozzle, and the small discharge ports 30 are arranged in a row.
As shown in FIG. 24 to FIG. 29, an apparatus for forming a flattened sample flow for analyzing particles comprises:
a flow cell 10 having a gradually narrowing lead-in passage 14, a narrow measuring passage 16 contiguous to the lead-in passage 14, a sheath liquid feed port 18 disposed in the lead-in passage 14, and a discharge port 20 disposed at the downstream side of the measuring passage 16, and
a sample nozzle 40 for discharging sample disposed in the lead-in passage 14 of the flow cell so that the front end may be directed to the measuring passage 16, wherein
the cross section of the measuring passage 16 of the flow cell 10 is rectangular with a side ratio of one to several times,
a sample nozzle 40 is disposed across the flow of the sheath liquid in the lead-in passage 14,
a plurality of small discharge ports 42 are disposed horizontally in a row in the sample nozzle 40 so as to open toward the measuring passage 16,
sheath liquid dividing means 13 disposed at the upstream side of the small discharge ports 42 of the sample nozzle 40 in contact with the sample nozzle 40 so as to divide the sheath liquid symmetrically into two flows, and
sheath liquid dividing means 13 disposed so that the lateral projecting direction of the sheath liquid dividing means 13 and the axial direction of the sample nozzle 40 may coincide.
In this case, instead of disposing a plurality of small discharge ports 42 in the sample nozzle 40, as shown in FIG. 30 to FIG. 32, a flat (slit) discharge port 44 may be disposed in the sample nozzle 40.
The sheath liquid is divided into two flows by the sheath liquid dividing means 13 projecting in the lateral direction. When the sheath liquid flows converge (confluence), the sample liquid discharge from the discharge port of the sample nozzle 12 is sandwiched, so that a flat sample flow is formed.
By flattening the discharge port of the sample nozzle or disposing a plurality of small discharge ports horizontally in one row, a further preferred flat sample flow is formed.
Moreover, when disposing the sample nozzle 40 across the lead-in passage 14, first the sample liquid is led into the nozzle from one end of the nozzle, and is discharged from the other end of the nozzle. The plural small discharge ports 42 or flat discharge ports 44 are disposed from one end of the sample nozzle to the other end, and therefore the supplied sample liquid is discharged from the plural small discharge ports or flat discharge ports, and a preferred flat sample flow is formed together with the action of the sheath liquid dividing means 13.
FIG. 2 to FIG. 4 relate to an apparatus for forming a flattened sample flow of the present invention. The apparatus comprises a flow cell 10 for forming a sheath flow, and a sample nozzle 12 which is a thin pipe for discharging the sample.
The flow cell 10 is made of transparent material such as glass and plastic, and comprises a lead-in passage 14 gradually narrowed in width in one direction only, a narrow measuring passage 16 contiguous to the lead-in passage 14, a sheath liquid feed port 18 disposed in the lead-in passage 14, and a discharge port 20 disposed at the downstream side of the measuring passage 16. The cross section of the measuring passage 16 is rectangular, with a side ratio of one to several times, or practically one to ten times, or preferably three to five times. If the side ratio exceeds 20 times, it is closer to the conventional flow cell, and hard to manufacture and likely to be broken.
In this apparatus, the sheath liquid for leading the sample into the measuring range c, while enveloping it from the surrounding is passed into the flow cell 10, and at the same time the sample is passed into the sheath liquid from the nozzle 12, so that the thickness of the sample flow is reduced (throttled) to a specific value (about the thickness of the particles to be measured, for example, about 10 μm when measuring erythrocytes in blood sample).
The width, al, of one side of lead-in passage 14 (see FIG. 2, FIG. 4) is constant, for example, at 1 mm, so that the width of the sheath liquid flow may not change near the front end of the nozzle 12, so that a reducing action is not exerted on the sample flow in the direction of the width al.
On the other hand, the width, b1, at the other side of the lead-in passage 14 (see FIG. 3, FIG. 4) is, different from the case above, gradually narrowed as it approaches the measuring passage 16 to a final width, b2, (see FIG. 3, FIG. 4), so that a reducing action is exerted on the sample flow. The width, b1, is, for example, 10 mm, and the width, b2, is, for example, 0.5 mm.
By disposing a conventional circular hole nozzle in the flow cell 10, the sample flow may be formed like a sheet or board, that is, a wide sample flow with a thickness of about 10 μm may be formed. In this method alone, however, a sample flow having a sufficient width for the measuring range of the imaging flow cytometer cannot be prepared.
Accordingly, by using the sample nozzles as shown in FIG. 5 to FIG. 15, the thickness of the sample flow flowing in the measuring passage 16 of the flow cell 10 may be further reduced to form a flat flow. This is described in detail below.
The imaging region is basically determined by the scale factor (magnification) of-the objective lens (not shown) and the size of the image pickup device of the video camera (not shown). For example, in the case of an objective lens with a scale factor of 10 times and a video camera CCD (changed coupled device) image pickup device of 2/3 inch, since the size of the light receiving surface of the CCD element is 8.8×6.6 mm, the imaging region in the flow cell 10 is 0.88×0.66 mm, or when the objective lens has a scale factor of 40 times, the imaging region is 0.22×0.165 ram, and therefore if the scale factor of the objective lens is 10 times, a sample flow width of 0.9 mm may be sufficient.
In the sheath flow measuring method, the sectional area of the sample flow running in the flow cell is determined by the flow rate ratio of the sample flow and sheath liquid flow. For example, using a conventional circular hole nozzle having only one sample flow outlet, if the sample discharge per unit time is 2.6 μl/sec and the flow rate of sheath liquid is 500 μl/sec, in the section of the measuring passage 16 of the flow cell, the area ratio occupied by the sample flow and sheath liquid is 1:187. Accordingly, as shown in FIG. 2 to FIG. 4, supposing the sectional area of the measuring passage 16 to be 1 mm×0.5 ram, the area occupied by the sample flow is 1/187 of 0.5 mm 2 that is 2.7×10 -3 mm 2
Suppose the sample flow can be reduced to 1/20 in one direction only. The value of 1/20 is determined by the shape of the flow cell.
In the conventional circular opening nozzle, if the diameter of the sample flow right after being discharged therefrom is, for example, 0.2 mm, the thickness of the sample flow in the measuring region, c, is 1/20, that is, reduced to 10 μm.
Comparing this result with the result of the area occupied by the sample flow in the measuring passage 16 mentioned above, the size of the region occupied by the sample is obtained as 0.01 mm×0.27 mm. The diameter of the flat flow is 0.27 mm, which is found to be only about 1/3 of the desired imaging region width of 0.9 mm.
To solve this problem, it may be possible to
(a) to increase the sample discharge volume three times; or
(b) to increase the opening area of sample discharge port three times (without changing the flow rate).
However, plan (a) has the following problems. That is, the area occupied by the sample flow in the measuring passage 16 is increased three times from the initial area. On the other hand, the diameter of the sample flow right after discharge from the nozzle is √3 times the initial value (three times in area). Hence, if reduced to 1/20, the thickness of the sample flow is √3 times the initial value. Accordingly, the width of the sample flow is 3/√3 =√3 times, and substantially both the thickness and width of the sample flow is √3 times, and therefore only the thickness cannot be increased three times while keeping the initial thickness.
With plan (b), the following problems are present. That is, the area occupied by the sample flow in the measuring passage 16 is unchanged. The opening area of the nozzle discharge port is 3 times (√3 times in diameter), and hence the diameter of the sample flow right after discharge is √3 times. Hence the thickness of the sample flow is √3 times, and the width of the sample flow is, to the contrary, 1/√3 times.
In plan (a), moreover, it may also be considered to increase the sheath liquid flow rate three times, but it involves the following problems. That is, the area occupied by the sample flow decreases to be one times, the thickness of the sample flow decreases to be one times, and the width of the sample flow is also one times.
Besides, by varying combinations the sample discharge, volume, sample discharge opening, and sheath liquid flow rate may be considered, but in any case it is not possible to obtain a sufficient flatness.
To solve the above problems, the present invention is intended to enhance the flatness of the sample flow further, by using a nearly elliptical sample discharge port as shown in FIG. 5 to FIG. 10, or a sample nozzle having multi-hole sample discharge ports arranged in one row as shown in FIG. 11 to FIG. 15.
As mentioned above, if the passage reducing rate is 1/20 times, the diameter of the discharge aperture of the nozzle front end is 0.2 mm, the flow rate of sheath liquid per unit time is 500 μl/sec, and the sample flow rate is 2.6 μl/sec, the sectional area of the sample flow in the measuring region is 10 μm×270 μm. To pass the sample in the entire imaging region, it is necessary to discharge the sample approximately 3.3 times more per unit time, that is, more than 8.6 μl/sec.
In the sample nozzle 12 shown in Fig..5 to FIG. 9, the width d, (see FIG. 9) in the thicknesswise direction in the sample discharge port 22 at the nozzle front end is, for example, kept at 0.2 mm, and the length of the discharge port 22 is, for example, 3.3 times or 0.66 mm.
In FIG. 5 to FIG. 9, for example, a taper 24 is disposed for a specific length from the front end of the nozzle 12, and a nearly elliptical discharge port 22 is formed, but it does not matter if a step form is provided instead of the taper form. Numeral 26 denotes a sample flow inlet.
As shown in FIG. 9, supposing the central part of the nearly elliptical discharge port 22 and the sample flow inlet 26 to be present on the same straight line, it is hard to divide the flow uniformly, and therefore it is desired to shape the discharge port as shown in FIG. 10, that is, the width of the end portion 28 should be slightly broader than the width of the central part.
In FIG. 11 to FIG. 15, another example of a sample nozzle 12a is shown. In the sample nozzle 12a of this case, for example, the flow rate per unit time is increased 3.3 times by arranging several holes of 0.2 mm in a row, and a sample flow of 10 μm×270 μm is formed per hole, so that it is enough at a maximum to form three or more holes of 0.2 mm at every pitch of 0.27 mm. However, as shown in FIG. 12, when multiple holes are arranged in a comb form, if there are discharge ports on the same straight line as the original sample flow inlet 26, it is hard to divide the flow uniformly, and therefore it is desired to dispose four or six small discharge ports 30 symmetrically to the original sample flow inlet 26. Moreover, in order to make the flow rate from each small discharge port 30 uniform, the central holes may be smaller (for example, 0.15 mm), and the outside holes may be larger (for example, 0.25 mm). This method, however, differs with the number of holes opened in the nozzle front end, and the hole diameter may not always be as specified herein.
In FIG. 12, the sample nozzle 12a is, for example, composed of a main body member 32 and a front end member 34. The main body member 32 has one sample flow inlet 26, and the front end member 34 has, for example, six small passages 36 arranged horizontally in one row. The main body member 32 and front end member 34 are bonded so that the passages may mutually communicate and be formed into one body.
In order to dispose plural small discharge ports at the front end of the sample nozzle, aside from the construction above, it may also be possible to insert plural small pipes into the nearly elliptical discharge port 22 shown in FIG. 5, or install plural partitions in the discharge port 22. The shape of the small discharge ports may be, aside from circle, quadrangle, polygon or other shape.
The present invention explained in FIG. 2 to FIG. 15 is thus composed, and hence brings about the following effects.
(1) Not only the lead-in passage is narrowed in one direction, but also the discharge port of the sample nozzle front end is formed in a flat elliptical form or as multiple holes, and therefore a flat sample flow may be easily formed in a rectangular passage with an aspect ratio of one to several times, or a nearly circular measuring passage, if not in the flat measuring passage as in the prior art.
(2) Since the passage of the flow cell may be formed as nearly a square or circle, it is easy to manufacture the flow cell, and its strength may be enhanced. Hence, the manufacturing cost may be reduced, and damages decreased.
FIG. 16 to FIG. 18 relate to another embodiment of an apparatus for forming a flattened sample flow according to the present invention. This apparatus comprises a flow cell 10 for forming a sheath flow, a sample nozzle 12 which is a thin pipe for discharging sample, and a sheath liquid dividing means 13 for dividing the sheath flow symmetrically into two flows.
The flow cell 10 is made of a transparent material such as glass, acrylic and other resin, and comprises a gradually narrowing lead-in passage 14, a narrow measuring passage 16 contiguous to the lead-in passage 14, a sheath liquid feed port 18 disposed in the lead-in passage 14, and a discharge port 20 disposed at the downstream side of the measuring passage 16. Incidentally, a denotes the measuring region. The cross section of the measuring passage 16 is rectangular, with a side ratio of one to several times, or practically one to ten times, or preferably three to five times. If this side ratio exceed 20 times, it is closer to the conventional flow cell, which is hard to manufacture and is likely to be damaged.
In FIG. 18, C1 is a sample discharge means such as a syringe, C2 is a sample liquid tank, and V1, V2 are valves.
In measuring, first valves V1, V2 are opened, and the sample liquid is led to the nozzle 12. Next, the valves V1, V2 are closed, and the syringe C1 is operated, so that the sample is discharged from the nozzle 12 by a specific volume.
The sheath liquid dividing means 13 is composed of, for example, a plate 15 which contacts the sample nozzle 12 and projects in the lateral direction, and a wedge part 17 formed consecutively on the upper part of the plate 15.
In the apparatus of the present invention, for example, by using the sample nozzle as shown in FIG. 5 to FIG. 15 above, the thickness of the sample flow running in the measuring passage 16 of the flow cell 10 may be further formed in a thinner flat flow.
In the sample nozzle 12 shown in FIG. 5 to FIG. 9, the taper 24 is formed for a specific length from the front end of the nozzle 12, and the nearly elliptical discharge port 22 is fabricated, but instead of the taper, a step form may be formed. Numeral 26 denotes a sample flow inlet. In FIG. 9, meanwhile, the shorter diameter d of the nearly elliptical discharge port 22 is, for example, about 0.2 mm.
FIG. 11 to FIG. 15 represent another example of the sample nozzle 12a. In this sample nozzle 12a, for example, several holes of about 0.2 mm are arranged in a row, and hence the flow rate per unit time is increased. However, as shown in FIG. 12, when multiple holes are disposed in a comb form, if the discharge ports are present on the same straight line as the original sample flow inlet 26 at the passage branching portion, it is hard to divide the flow uniformly, and hence it is desired to open four or six small discharge ports 30 symmetrically to the original sample flow inlet 26. Furthermore, to make the flow rate from each small discharge port 30 uniform, the central hole may be smaller (for example, about 0.15 mm), and the outside holes may be larger (for example, about 0.25 mm). This method, however, differs with the number of holes opened in the nozzle front end, and the hole diameter is not always equal to this size.
In the flow cell 10, as shown in FIG. 18, there are several portions shown for controlling the sheath liquid, that is, sheath flow stabilizing portion A, sheath flow dividing portion B, and sheath flow converging portion C.
The sheath liquid flows in from the sheath liquid feed port 18 in the upper part of the flow cell, and is decelerated in the sheath flow stabilizing portion A to be formed into a laminar flow. For example, supposing the inside diameter of the sheath flow stabilizing portion A to be 10 mm, the flow velocity to be 6.3 mm/sec, the viscosity to be μ=1.002, and the density to be ρ=998 kg/m 3 , the Reynolds number Re is about 0.063, which satisfies the laminar flow condition. At this time, the flow velocity distribution is a parabolic profile as shown in FIG. 19.
Afterwards, the sheath flow is divided into two flat flows by the dividing portion B. In the dividing portion B the sheath liquid dividing means 13 is formed into a proper shape (for example, wedge shape ) at its front part, so that the sheath liquid is divided into two flat flows as shown in FIG. 20, while keeping the flow in a laminar state.
At, in the rear portion of the sheath liquid dividing portion 13, the flow is converted into two flat flows, as shown in FIG. 21, the flow velocity profile is formed in three layers, in which the flow velocity is slow in the central portion, and fast at in the both sides. This flow runs into the measuring passage 16 as shown in FIG. 21, while finally changing into one flow having a parabolic flow velocity profile.
Accordingly, by disposing the sample discharge port of the nozzle 12 in the rear portion of the sheath liquid dividing means 13, that is, in the portion where the flow velocity is the lowest, when the sample is discharged, the sample forms a sandwiched flow being held by the two flat flows of the sheath liquid.
This sandwich flow is later compressed by the taper part of the lead-in passage 14, and runs into the measuring region while keeping the three-layer sandwich structure.
In the conventional method not utilizing the sheath liquid dividing means, as shown in FIG. 19, the flow velocity distribution is parabolic and symmetric in rotation with respect to the flow direction, and the sample discharged from the front end of the nozzle 12 receives a compressive pressure F from all vertical directions to the flow direction as shown in FIG. 22, and the flat flow gradually converges on one point.
By contrast, in the apparatus of the present invention having the sheath liquid dividing means 13, the sample discharged from the front end of the nozzle 12 is sandwiched by two sheath liquid flat flows, and therefore receives the compressive force F only from the vertical direction (or lateral direction) as shown in FIG. 23, so that a stable flat sheath flow may be obtained.
Besides, by inserting the sheath liquid dividing means 13, the converging position of two flat flows is determined automatically, and if the front end of the nozzle 12 is put at a slightly deviated position from the flow direction, its effect on the thickness of the sample flow in the measuring region is small, and the front end position of the sheath liquid dividing means 13 becomes a guideline for mounting the nozzles, so that the nozzle may be mounted easily.
Thus, by forming the sheath flow stabilizing portion A and dividing portion B in the flow cell 10 and also the converging portion C for joining two flat flows, a stable flat sheath flow may be formed. Meanwhile, the sheath liquid dividing means 13 may be disposed in the lead-in passage 14 so as to envelope, nearly in contact, the sample nozzle 12, or may be directly mounted on the sample nozzle 12.
Another embodiment of the present is explained while referring to FIG. 24 to FIG. 32. In this embodiment, a sample nozzle 40 is disposed at the rear end of the sheath liquid dividing means 13, and the sample nozzle 40 is positioned vertically in the flow direction of the sheath liquid. The method of forming a flat sheath flow is the same as in the foregoing embodiment, and its explanation is omitted herein.
In the apparatus shown in FIG. 16 to FIG. 18, the position of the sample liquid drawn in and held before the start of a measurement, that is, the distance from the branching point above the nozzle and the front end of the nozzle 12 is long, and before the start of a measurement, the inside of the nozzle is filled with a cleaning liquid, so that it was necessary to discharge a large volume of sample from the nozzle (about ten times the sample volume to be measured) until the concentration of sample discharged from the nozzle discharge port reaches a stable concentration (normal sample concentration). Accordingly, a waiting time of 5 to 10 seconds was necessary from the start of feeding a sample into the nozzle until the measurement was actually started.
In this embodiment, in order to shorten the distance from the holding position of the sample liquid to be used in a measurement to the sample discharge port of the nozzle, the inside of the nozzle is filled with sample before filling with sample in the step before measurement, and when the sample is discharged from the sample discharge port of the nozzle, measurement is started at the same time.
In measuring, first valves V1, V2 are opened, and the sample liquid is led nearly to the nozzle 12. Next, the valves V1, V2 are closed, and the syringe C1 is operated, so that the sample is discharged from the nozzle 12 by a specific volume.
More specifically, as shown in FIG. 24 to FIG. 27, in the lead-in passage 14, the sample nozzle 40 is disposed across the flow of the sheath liquid. In the lower surface of the sample nozzle 40, as shown in FIG. 27 to FIG. 29, a plurality of small discharge ports 42 are disposed to open toward the measuring passage 16. The small discharge ports 42 communciate with the sample flow inlet 26 of the sample nozzle.
At the upstream side of the small discharge ports 42 of the sample nozzle 40, the sheath liquid dividing means 13 is disposed so as to contact the sample nozzle 40. The lateral projecting direction of the sheath liquid dividing means 13 and the axial direction of the sample nozzle 40 are identical.
Moreover, instead of disposing a plurality of small discharge ports 42 in the sample nozzle 40, as shown in FIG. 30 to FIG. 32, a flat discharge port 44 may be disposed in the sample nozzle 40.
The other constitution and action are the as in the foregoing embodiment.
The invention explained in FIG. 16 to FIG. 32 is thus constructed, and brings about the following effects.
(1) By disposing sheath liquid dividing means projecting in the lateral direction at the upstream side of the sample discharge port, and dividing the sheath liquid into two flows and joining them again, the sample is enveloped with sheath liquid in a sandwich form, so that a flat sample flow may be formed without using a passage flowing a large aspect ratio as in the prior art. Thus, the passage may be close to a square, and the manufacturing cost is reduced, and the risk of breakage is elimianted.
(2) By flattening the discharge port of the sample nozzle or disposing a plurality of the discharge ports horizontally in one row, a more favorable flattened sample flow may be formed.
(3) When disposing the sample nozzle across the lead-in passage, the route to the discharge port may be shorter, and hence the sample discharge preparation time may be cut short. At the same time, contamination between samples may be decreased, and the volume of sample to be prepared may be saved.
Having described preferred embodiments of the present invention with reference to the accompanying drawings, it is to be understood that the present invention is not limited to those precise embodiments, and that various changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the present invention as defined in the appended claims.
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An apparatus for forming a flattened sample flow by passing a sample (liquid specimen) containing particle components such as blood and urine, in a broad, thin, flat flow. This apparatus is preferably used in an apparatus for analyzing particle images by emitting a strobe light to a sample flat flow, and taking the still images of the particle components. More specifically, the cross section of a measuring passage of a flow cell is rectangular with a side ratio of one to several times, with a shape that gradually narrows in width only in one direction of the lead-in passage, and the discharge port at the front end of the sample nozzle has a flat opening, or small discharge ports are arranged horizontally in a row. The decreasing direction of the width in the lead-in passage and the shorter diameter direction of the flat discharge port or the direction of the small discharge ports arranged horizontally in a row are matched. Besides, the cross section of the measuring passage of the flow cell is rectangular with a side ratio of one to several times, and sheath liquid dividing means disposed at the discharge port upstream side of the sample nozzle for dividing the sheath liquid into two symmetrical flows. The sample nozzle is placed so that the discharge port may be positioned at the converging region of the sheath liquid. For further enhancing the flatness of the sample flow, a sample nozzle having a flat discharge port, or plural discharge ports disposed horizontally in a row is used.
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BACKGROUND OF INVENTION
This invention relates in general to monitoring of radiation sources, and in particular to the use of frequency lockers for monitoring frequency shift of radiation sources. The invention is particularly useful for enhancing performance of wavelength division multiplexing in fiber optics communication.
As fiber optics matures and gradually replaces microwave links in telecommunication industry, there is great need for increasing the capacity of these optical links. One way to achieve higher capacity is to increase bit rate of the link. This is called time division multiplexing, where multi-Giga bit of data is transmitted across this media. While time division multiplexing is adequate for moderate speed links, high capacity links have increasingly turned to wavelength division multiplexing (WDM), where multiple wavelength channels are simultaneously used to transmit data across the fiber.
WDM based systems have evolved rapidly from early two channel systems to the current 8 channel system. International Telecommunication Union (ITU) has even proposed a 45 channel system utilizing wavelength range from 1533 to 1565 nm with channel spacing of 100 GHz (about 0.8 nm). This system, referred to herein as the ITU system, is pushing the state-of-art of the various fiber optics components. It challenges optical component manufacturers to provide ultra-narrow bandwidth filters, transmitting lasers with highly stable frequencies, and optical components with high bandwidth capability etc. This invention relates to the enhancement of laser stability attained via the application of Fabry-Perot interference filter in laser frequency monitoring and control.
The currently deployed laser systems are based on Distributed feedback (DFB) lasers operating in 1550 nm range. These lasers can be tuned in frequency by heating or cooling the laser using Thermal electric cooler. However, there is up until now, no frequency reference at reasonable cost for these lasers to lock on to establish less than 0.1 nm wavelength shift over the field operating temperature range from -20 to 85° C. This invention describes the many implementations of this stable reference filter based on Fabry-Perot interferometer principle.
It is, therefore, desirable to provide a frequency reference at reasonable cost for lasers in order to maintain the laser at predetermined frequencies.
SUMMARY OF THE INVENTION
One aspect of the invention is directed towards a method for locking the frequencies of a plurality of radiation sources substantially to predetermined equally spaced frequencies spaced apart by a predetermined frequency spacing, comprising providing one or more frequency lockers each having equally spaced periodic frequencies with a free spectral range (FSR) substantially equal to the predetermined frequency spacing, wherein said periodic frequencies are close to the predetermined frequencies; and passing radiation from each of the sources through the locker or one of the lockers. The method further comprises detecting radiation passed by the locker or one of the lockers; providing first outputs and adjusting the frequency of each of the sources in response to one of said first outputs.
Another aspect of the invention is directed towards an apparatus for locking the frequencies of a plurality of radiation sources substantially to predetermined equally spaced frequencies spaced apart by a predetermined frequency spacing, comprising one or more frequency lockers, the locker or each of the lockers having equally spaced periodic frequencies with a free spectral range (FSR) substantially equal to the predetermined frequency spacing; means for passing radiation from each of the sources through the locker or one of the lockers; one or more first detectors detecting radiation passed by the locker or one of the lockers to provide first outputs; and means for adjusting the frequency of each of the sources in response to one of said first outputs.
Yet another aspect of the invention is directed towards a frequency sorting device, comprising an etalon having an optical path length that is accurate to about 0.5 microns or better; an input optical fiber supplying radiation to the etalon and an output optical fiber delivering radiation from the etalon.
One more aspect of the invention is directed towards a frequency sorting method, comprising providing an etalon having an optical path length that is accurate to about 0.5 microns or better; supplying broadband radiation to the etalon and delivering from the etalon radiation having periodic peak frequencies with a frequency spacing.
Still one more aspect of the invention is directed towards a frequency sorting method, comprising providing an etalon having an optical path length that is accurate to about 0.5 microns or better; supplying radiation within a passband to the etalon and delivering radiation having a narrower bandwidth than the passband from the etalon.
An additional aspect of the invention is directed towards an optical device comprising an etalon having two reflective surfaces and a first GRIN lens abutting one of the surfaces.
Still another aspect of the invention is directed towards a method for making an etalon, comprising determining a desired optical path length for the etalon; providing two reflective surfaces and adjusting the optical path length of the etalon. The adjusting includes changing a distance between the surfaces or altering an angle of incidence of a beam of radiation on said surfaces, so that an optical distance through an optical medium between the surfaces is substantially equal to the desired optical path length, said changing including thin film deposition or etching.
One more aspect of the invention is directed towards a multiplexer system comprising a plurality of radiation sources providing radiation at predetermined equally spaced frequencies spaced apart by a predetermined frequency spacing; a plurality of optical channels, each channel conveying radiation from a corresponding source to a wavelength division multiplexer or from a wavelength division demultiplexer. The system further includes a frequency locker having equally spaced periodic frequencies with a free spectral range (FSR) substantially equal to the predetermined frequency spacing for detecting a frequency shift of radiation from each of the sources and to provide an output; splitters, each splitter diverting a percentage of radiation from a corresponding optical channel; a multi-channel switch sequentially providing radiation diverted by one of the splitters to the frequency locker to sequentially detect a frequency shift in the plurality of sources and means for adjusting frequencies of the plurality of sources in response to the output.
Yet another aspect of the invention is directed towards a method for locking the frequencies of a plurality of radiation sources to International Telecommunication Union (ITU) frequencies, comprising measuring a frequency shift of said sources relative to said ITU frequencies; and adjusting the frequencies of said radiation sources in response to said frequency shift so that such frequencies are substantially equal to said ITU frequencies.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a graphical illustration of Fabry-Perot spectral lines of an etalon in reference to ITU frequencies useful for illustrating the invention.
FIG. 1B is a block diagram of an optical system including a frequency locker for adjusting the frequencies of radiation emitted by a laser to illustrate the preferred embodiment of the invention.
FIG. 2A is a schematic view of an etalon useful for illustrating the invention.
FIG. 2B is a graphical plot of the transmittance of radiation through the etalon of FIG. 2A to illustrate the invention.
FIG. 3 illustrates a basic Fabry-Perot etalon.
FIG. 4 is a cross-sectional view of a composite etalon, where the spacing between two reflective surfaces is filled by two different optical materials to illustrate one embodiment of the invention.
FIG. 5 is a cross-sectional view of an etalon with two spacers, one on each side, between two reflective surfaces to illustrate another embodiment of the invention.
FIG. 6 is a cross-sectional view of an etalon with a spacer between two reflective surfaces where the spacer is on one side of the spacing.
FIG. 7 is a partially cross-sectional and partially schematic view of another etalon where the space between two reflective surfaces is evacuated to illustrate yet another embodiment of the invention.
FIG. 8 is a cross-section view of an optical fiber, a ferrule and a GRIN lens to illustrate a collimating device useful in the invention.
FIG. 9A is a cross-sectional view of an optical system including an etalon and a pair of GRIN lenses, one on each side of the etalon and ferrules to illustrate another aspect of the invention.
FIG. 9B is a spectrum of the radiation input to the system of FIG. 9A.
FIG. 9C is the spectrum of radiation emerging from the system of FIG. 9A.
FIG. 10A is a block diagram of a multiplexer system employing frequency lockers to illustrate yet another aspect of the invention.
FIG. 10B is a block diagram of a multiplexer system where only one frequency locker is used for controlling the frequencies of a number of lasers to illustrate still another aspect of the invention.
FIG. 11 is a cross-sectional view of a GRIN lens illustrating how the angle of incidence can be controlled by selecting the distance of an incoming beam of radiation from the axis of the lens useful for illustrating the invention.
FIG. 12 is a cross-sectional view of an etalon and two GRIN lenses adjacent to or abutting the etalon to illustrate a method for altering the optical path length of the etalon by changing the distance between an input radiation beam from the axes of the lenses to illustrate yet another aspect of the invention.
FIG. 13A is a schematic view of an etalon that can be used as a filter.
FIG. 13B is a spectrum of radiation that is input to the filter of FIG. 13A.
FIG. 13C is a spectrum of radiation emerging from the filter of FIG. 13A.
FIG. 14A is a schematic view of a filter system comprising a filter with a passband followed by an etalon to illustrate still another aspect of the invention.
FIG. 14B is a spectrum of the radiation input to the filter system of FIG. 14A.
FIG. 14C is the spectrum of radiation emerging from the filter system of FIG. 14A.
For simplicity in description, identical components are labelled by the same numerals in this application and figures.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The proposed ITU frequencies, separated by 100 GHz, are also known as ITU grid. This uniform frequency spacing is also very suitable to Fabry-Perot (F-P) based frequency filter. The F-P filter has also uniform spaced transmission peaks as shown in FIG. 1A and can be designed to match ITU grid. Thus, a group of lasers, providing radiation at frequencies that are separated by a frequency spacing of 100 GHz, can all be monitored and controlled by one Fabry-Perot reference filter, or called wavelength locker in the present invention so that they emit radiation substantially at the ITU frequencies. The economic benefit of one universal wavelength locker applicable to control a group of lasers is self-evident. This avoids the need to stock more than 30 items of wavelength lockers for each of the wavelength channels. For simplicity, the monitoring of one laser source is first described.
In order to monitor frequency shift of a laser from a corresponding ITU frequency, the radiation from the laser is passed through a Fabry-Perot etalon. The etalon is designed so that peaks of Fabry-Perot etalon spectral lines are slightly displaced from the ITU frequencies as indicated in FIG. 1A. The center frequency of the laser should be equal to a corresponding ITU grid frequency. As the center frequency of the laser is shifted away from the corresponding ITU frequency, the output power through the Fabry-Perot filter is also changed. By detecting the power change, the direction of wavelength or frequency shift can be judged and the correction to shift is turned on by heating or cooling the laser. Thus, in reference to FIG. 1A, if the power output through the filter or etalon decreases, this indicates that the frequency of the laser has decreased and shifted to the right in FIG. 1A. This means that the laser frequency should be increased. Of course, the opposite will hold if the spectral peaks are on the right side of the corresponding ITU frequencies instead of on the left side as shown in FIG. 1A.
FIG. 1B shows a physical configuration of wavelength monitoring scheme 10 using a wavelength locker. Light from a laser diode 12 is passed through an optical fiber 14 which serves as the main transmission line. A small percentage, saying 5%, of light is tapped out of the main transmission line 12 by a 95/5 fiberoptic splitter 16. The 5% side stream is further unevenly split by splitter 18 into two lines 22 and 24, e.g. 20% and 80%, respectively. The 80% line 24 goes through the wavelength locker 26 before entering the Detector 2. The output power of wavelength locker 26 will be changed if the central wavelength as well as total emitting power of the laser diode is changed. The 20% power directed to the Detector 1 directly is used as a reference of output power of the laser diode. Using the output of Detector 1 to normalize the output of Detector 2, changes in the normalized output of Detector 2 are caused solely by the wavelength or frequency shift of the laser diode. The outputs of two detectors are connected to a CPU or computer, which processes the data and sends a command to adjust the temperature of the laser diode by the built-in thermal-electric (TE) cooler. Therefore, a closed feedback loop is formed for tuning the wavelength to match the ITU grid. In this manner, frequency shift of the laser can be corrected by such tuning.
FIG. 2A is a cross-sectional view of a Fabry-Perot interferometer to illustrate the basic working principle of Fabry-Perot interferometry, which form the basis of Fabry-Perot interference filter. A Fabry-Perot interferometer relies on the interference of multiple reflected beams. As shown in FIG. 2A, incident light 100 experiences multiple reflections at each coated reflective surface, 101 and 102, respectively. Whenever there is no phase difference between the successive waves, constructive interference is produced and thus a transmission maximum occurs. In contrast, when there is a phase difference of 180° with successive waves, the transmission is minimum. In terms of mathematical interpretation, the transmission maximum occurs when round trip optical path length through the spacer 103 is an integer number of whole wavelengths. Namely,
2d×n×cos θ=m λ (1)
where d is the thickness of the spacer, n is the index of refraction of the spacer, and θ is the internal angle of reflection as shown in FIG. 2A, that is, the angle between beam 100 and a normal direction to surface 102 or 101. The transmission peak can be made very sharp by increasing mirror reflectivity. A typical transmission curve is shown in FIG. 2B. The spectral transmission full width half maximum is denoted as FWHM, and the interference fringe spacing in either frequency or wavelength is called free spectral range (FSR). Thus, the interference is controlled by the optical path length of the etalon, where the optical path length is determined by the spacing between the two reflective surfaces 101, 102, angle θ and the index of refraction n of the optical medium between the surfaces 101, 102. Where θ is zero, the product of the spacing and index of refraction is called optical length. These parameters determine frequency spacing (FSR as shown in FIG. 2B) between transmission peaks and the exact location of the peaks.
The above-described method for tuning lasers will result in accurate tuning if the optical path length of the etalon in the Fabry-Perot filter remains substantially unchanged despite temperature change and other environment influence. Thus, optical components used in wavelength division multiplexing and demultiplexing may be used in an environment where the temperature may range from -20° to 85° C. As material that is used in the etalon expands or contracts, this may cause the optical path length to change, thereby affecting stability of frequency peak location and frequency spacing of the etalon. Thus, in applications such as wavelength monitoring in fiberoptic wavelength division multiplexing transmission, the optical design of etalon and material selection for the spacer are critical.
The present invention is also directed to various techniques to overcome instability in thickness d, n and θ in equation (1) above due to environmental influences. With proper engineering design and material selection, the precision of Fabry-Perot filter can be made high enough to satisfy fiber optic telecommunication or cable TV transmission stability requirements.
The most significant factor affecting the accuracy of Fabry-Perot filter is the temperature effect on the pass band of the filter. For telecommunication, field application temperature range encountered is typically from -20° C. to 85° C. Fabry-Perot filters constructed from normal transparent materials would have temperature coefficient of 10 -5 per ° C. This would translate into about accuracy of 10 -3 , i.e. a shift in peak location of 0.1% of the wavelength, which would be inadequate for laser frequency monitor and control applications.
In the present invention, it is contemplated that by using specially selected materials, construction and alignment procedure, different types of etalons can be constructed to satisfy various applications. Also the integration of etalons to optic fibers is presented.
FIG. 3 illustrates a basic Fabry-Perot etalon. Both end surfaces, 31 and 32 of the spacer 30 are coated with reflective coating. For application in 1550 nm as well as 1300 nm region, the coating is optimized for high reflectivity in these regions. For 100 GHz free spectral range, and for material made of Fused Silica, the thickness is about 1.027 mm. To optimize this filter in terms of thermal stability, an optical glass transparent in 1550 nm and 1300 nm, with low thermal coefficient of expansion (TEC) and negative dn/dt (ratio of index change to temperature change) is preferably used. The thermal coefficient of optical thickness is therefore defined as the collective effects of thermal expansion of physical size and refraction index change against temperature change. FK51 glass from Schott Glass Inc. (Duryea, Pa. 18642, USA) is an example of negative dn/dt (about 7.0×10 -6 /° K) with average thermal coefficient of expansion of 15×10 -6 . The thermal coefficient of optical thickness of FK51 is only -1.0×10 -6 /° K.
An ideal transparent material between the reflective surfaces has a low thermal expansion coefficient and negative dn/dt, so that the net optical length change as a function of temperature is minimized. Ultra low expansion (ULE) glass like Zerodur™ manufactured by Schott Glass Inc. and ULE™ glass by Corning Glass Inc. (Corning, N.Y. 14831) are good candidates, because they have almost zero TEC and small dn/dt. By using ULE™ glass, the accuracy is to be 10 -4 over 100° temperature excursion or range.
FIG. 4. is a schematic view of a composite etalon, where two different optical materials, a spacer portion 41 of material A with positive temperature coefficient of optical length and a spacer portion 42 of material B with negative temperature coefficient such as Acrylic and Polycarb (cited from a paper published by Thomas Jamieson, Optical Engineering, Vol. 20(2), 1981, pp. 156-160, are stacked together and placed between the two reflective surfaces 31, 32 to provide minimum temperature sensitivity. The method to do so is as follows:
Assuming the free spectral range of the etalon is 100 GHz. The thickness for a typical fused Silica is 1.00 mm. Since fused Silica has positive temperature coefficient, this means that if the free spectral range is 100 GHz at -10° C., then at 85° C. the Free spectral range becomes 99.95. The composite scheme is to use a negative temperature coefficient material such as Schott glass FK51 to compensate for the positive coefficient of fused Silica. Suppose FK51 glass of thickness 1.00 mm change FSR from 100 GHz to 100.05 GHz over the temperature range from -20 to 85° C., then the composite etalon should be of the following construction: Fuse Silica 0.5 mm and FK51 0.5 mm. In general, the thermal compensation can be accomplished with any pair of positive/negative temperature coefficient optical glass. It is assumed that thermal coefficient HA of material A (41) in FIG. 4 is a positive value, and thermal coefficient HB of Material B is negative. Then, the optical thickness ratio for Material A is given by
|HB|/(HA+|HB|) (2)
Thickness for Glass A=|HB|/(HA+|HB|)*Ta
where Ta is the desired ideal optical thickness for etalon.
Similarly, for material B, optical thickness ratio for Material B is given by
HA/(HA+|HB|) (3)
Therefore, composite material thickness for Material B is given by
Thickness for B=HA/(HA+|HB|)*Tb
With this simple composite etalon construction, the thermal instability can be reduced by a factor of 10. An iterative procedure can reduce the thermal effect further. However, if the thermal effect is not a constant over the temperature range of -20 to 85° C., or if there is a wavelength dependent effect then we must take these factors into account. Nonetheless, a factor of 10 improvement is easily achievable. Material A and Material B can be kept in optical contact or bonded together by adhesive. By the above composite configuration, the error in free spectral range as well as center wavelength is as low as 10 -5 over 100° C. temperature excursion.
FIG. 5 shows another embodiment of high accuracy etalon accomplished by a stable air gap. 51 and 52 are transparent material with reflectivity coatings on inner side of cavity as indicated by 53 and 54, respectively. The stability of air gap path is achieved by using temperature stable material such as Corning's ULE™ or Schott's Zerodur™ as spacer material in spacers 55 and 56, one on each side of the optical path between reflective surfaces 53, 54 on two supports 51, 52. Both materials have less than 10 -7 thermal coefficient of expansion and thus we can achieve 10 -5 thermal stability. The spacing for 100 GHz Free spectral range corresponds to 1.5 mm thickness for the spacer. The spacer need not be at the periphery of the device. Any "spacer` configuration which can maintain air optical length constant will do. In FIG. 6, a ULE™ glass 61 is placed sideways between two pieces of flat glass, 63 and 64. The light beam is passed through the air gap and bounced back and forth between the reflective coatings, 65 and 66.
The accuracy of the design in FIGS. 5 and 6 is limited by the small residual thermal expansion and optical path length change of air inside the gap. The index of refraction of air at standard temperature and pressure (STP) condition at 1550 nm is 1.000225. The change of refraction index of air is affected by temperature, pressure and humidity. The accuracy of this type of air gap etalon is between 10 -5 and 10 -6 . The spacer in FIGS. 5 and 6 may have a thickness (i.e. direction along an optical path for the etalon) within a range of 0.85 to 1.05 mm, or an integral or fractional multiple thereof. The air gap may be within a range of 1.4 to 1.6 mm, or an integral or fractional multiple thereof.
As a direct consequence of error introduced by air and error correction/compensation from other material or construction, the vacuum gapped etalon as shown in FIG. 7 is painstakingly constructed to attain the ultimate stability.
Since air introduces about one part per million of error and Zerodur™ introduces about 1 -3 part per million of error over temperature range of -20 to 85° C., if we want to have higher accuracy than this, vacuum gap is preferably used between the reflective coatings or pedestals 73A, 74A. When a vacuum is in the gap between the surfaces, no optical path length change takes place that is caused by changes in the medium between the reflective coatings. If ULE™ glass is used to construct spacers 71A, 71B, since such material has 0 thermal coefficient of expansion, this device should have parts per billion stability.
However, if due to batch to batch variation, the gap width is still temperature sensitive, a compensation scheme, illustrated in FIG. 7 can be utilized. If the spacers 71A, 71B have residual thermal expansion coefficient of 10 -8 and spacing of 1.5 mm, we can compensate this expansion by putting a pedestal, 73A and 74A of 15 um (30 um total) in thickness on each of the fused Silica end caps, 73 and 74, respectively, assuming Fused Silica has TEC of 5×10 -7 . (The ratio of TEC is 50. The total thickness of the pedestals required for compensating the temperature effects of temperature change on spacers 71A, 71B is 1.500 mm/50=30 um. Thus the thickness of each pedestal on the end caps or pieces is 15 um. In this way, as the spacers expand, the pedestal also expands to cancel out the spacer expansion and thus results in no change in the distance or gap between the pedestals 73A, 74A. Tube 77 connect the chamber or cavity 70 between the reflective surfaces to a vacuum pump (not shown). After the vacuum is achieved in the cavity 70, the vacuum passage can be blocked at a location indicated by an arrow 78 to keep the vacuum condition. The vacuum gap between the two reflective surfaces may be within a range of 1.49 to 1.51 mm, or an integral or fractional multiple thereof.
Depending on the thickness of the optical interference coatings (pedestal) 73A, 74A, the thermal expansion of the coatings may have to be taken into account. However, this is second order effect, because the coating is only 1 to 2 um thick. In any case, if need be, this effect can be compensated for. The expected error after the above-described compensation is applied is of the order of 10 -6 or less over a temperature range of -20 to 85° C.
To achieve low loss in Fabry-Perot etalon as well as render it useful and practical, the incident light to the etalon is preferably well collimated. FIG. 8 illustrates a collimating means including a Gradient Index (GRIN) lens and a ferrule. The fiber 81 is secure inside the center hole 83 of the ferrule 82. The light exiting ferrule at face 81A is collimated to become a parallel beam through a GRIN lens 84 with a proper length. Collimating means other than a GRIN lens may also be used.
FIG. 9A shows an embodiment integrating etalon to fibers via a pair of GRIN lenses. Fabry-Perot etalon 90 can be any type of the above mentioned etalons, including one where its optical path length is accurate to within 0.5 or even 0.2 microns. GRIN lenses 91 and 92 are adjacent to and preferably abut the opposite end surfaces of etalon 90, respectively. End surfaces 91A and 92B of Lens 91 and 92, respectively, can be either directly bonded to the end surfaces 90A and 90B of etalon 90 by adhesive or be kept separate therefrom by an air gap. If an air gap is elected, it is appropriate to apply anti-reflective coatings to the end surfaces 91A, 90A, 90B and 92B to reduce the unwanted reflection on these surfaces. Input fiber 97 and output fiber 98 are respectively secured inside the ferrule 97A and 98A. The light from fiber 97 becomes a parallel upon exiting GRIN lens 91. The parallel beam enters the etalon 90 and bounce back and forth within the etalon to do multiple interference. The transmitted light 99 is focused to output fiber 98 by the GRIN lens 92. In reference to FIG. 9B, where radiation having a broadband flat spectrum indicated by 910 is transmitted through the embodiment of FIG. 9A, a multiple peaks spectral is produced at the output in fiber 98, as shown in FIG. 9C as 920.
FABRICATION PROCESS
(A) Thickness Control:
As indicated above, it is desirable to maintain dimension stability of the etalon against temperature change and other environmental changes. This section describes how an etalon can be fabricated with dimension accuracy within 0.5 or even within 0.2 micron. If a universal wavelength locker applicable to all 100 GHz spacing ITU channels with peak inaccuracy within 5 GHz is desired, the dimensional accuracy of the optical thickness of etalon at room temperature will need to be within 0.2 micron. This dimensional accuracy is not easy to be achieved by grounding and polishing of glass. Vapor thin film deposition may be used instead, such as electron assisted deposition or chemical vapor deposition to increase the thickness of the spacer of etalon if the spacer is a little thinner, say by a few microns, than the ideal value. On the contrary, etching process such as wet etching and chemical vapor etching can be used to decrease the thickness if the spacer resulted from the polishing is originally thicker than the ideal dimension. The ideal vacuum gap corresponds to 100 GHz is 1.49896276 mm. By equation (1), every 0.2 micrometer deviation from the ideal vacuum gap will cause an 0.1 nm shift in location peaks of the etalon spectral line.
(B) Angle Tuning:
FIG. 11 illustrates how a Gradient index (GRIN) lens may be used in conjunction with an etalon mentioned above to form a tunable wavelength locker. The GRIN lens 111 has a geometrical and optical center axis 112. The lens 111 has two surfaces 113 and 114 perpendicular to the center axis 112. An incident ray 116 parallel to but at an offset distance r to the center axis 112 of the lens 111 strikes the surface 113. Due to a quasiparabolic refraction index distribution with the maximum index at the center of the GRIN lens 111, the ray 116 is bent toward the center and hits the surface 114 at point p with an angle θ L . It is important to know that the impinging angle θ L varies linearly with the displacement r from the center axis 112. If a quarter pitch GRIN lens is used, θ L =A 1/2 ×r, where A 1/2 is an index gradient constant that can be obtained from the SELFOC, a product Guide of NSG America, Inc., located in Somerset, N.J.
FIG. 12 illustrates a wavelength locker with the capability of adjusting the effective optical length of etalon and thus its peak location of spectral line. The input fiber 121 is displaced a distance r from the center axis or line 128 of the GRIN lens 123. The beam exiting the fiber 121 is collimated by the GRIN lens 123 and then exits the surface 123A with an angle to the normal of the surface. The beam then enters the etalon 125 with an angle θ. The internal angle θ reduces the effective optical length of etalon as indicated in Equation 1 by a factor of cos θ. By choosing an appropriate non-zero θ, the apparent center wavelength of the peak transmission may be decreased to a value substantially equal to a desired optical path length which corresponds to desired frequency peak and spacing values. The transmitted power is focused back to the output fiber 122 through the other GRIN lens 124.
FIG. 10A shows a four wavelengths WDM system with wavelength monitoring capability. Four individual wavelength lockers are used for monitoring wavelength drift of each of four wavelength channels. The system in FIG. 10A is equivalent to one including four of the systems in FIG. 1B where signals from the main channels of the four systems are multiplexed. Four wavelength lockers can have either the same or different optical characteristics. There is component redundancy in the monitoring function of FIG. 10A. In FIG. 10B, a more economical solution is proposed by using a fiberoptic multichannel switch. The multichannel switch 151 is used to select one channel for checking at a time by tapping light from one of the transmission lines at a time. The common fiber 152 of the multichannel switch 151 is connected to a monitoring functional block which is the same as system 10 in FIG. 1B. The typical switching time of a multichannel switch such as one proposed in U.S. Pat. No. 4,896,935 is about 100 millisecond which is two orders shorter than the typical time scale of laser wavelength drift. Longer scanning time periods for switching of switch 151 are possible, such as those up to 10 (i.e. at 0.1 Hz frequency) or 100 seconds. A CPU or computer 28 is used to control the surveillance of multichannel switch 151 for each wavelength channel so that the channels are monitored sequentially by sequentially connecting the tapped signal from a channel to the locker. The CPU also process power reading from the two detectors, 1 and 2.
Another advantage of F-P etalon is that the extremely narrow wavelength spacing between two peaks is practical by increasing the optical length of etalon. For example, by doubling the vacuum gap of 100 GHz ITU grid, an F-P spectral line of 50 GHz peak spacing is obtained. A 50 GHz spacing in frequency is equivalent to 0.4 nm spacing in wavelength, which is extremely difficult to be produced by thin-film coating filter or fiber grating filter. Therefore, for extremely narrow band transmission in wavelength division multiplexing system, a wavelength locker using a stable etalon as mentioned above can be used as a filter. FIG. 13A shows a F-P etalon type of wavelength locker 131 that can be used to produce a spectral line with multiple transmission peaks at wavelengths of λ n-1 , λ n , λ n+1 etc. Light or radiation carried on a fiber and with a broadband spectrum as shown in FIG. 13B enters the F-P wavelength locker 131, and leaves it with a multiple transmission peaks of spectral line indicated by 133 in FIG. 13C. In FIG. 14A, a relatively wide band filter 135 is added before the F-P wavelength locker 136. The filter 135 can be made by thin-film coating as disclosed in U.S. Pat. No. 5,453,827 invented by Ho-Shang Lee. The filter 135 is used to eliminate all transmission peaks except the one at λ n . Then, the wavelength locker 136 is used to further reduce the pass bandwidth. By this hybrid design, a pass bandwidth less then 0.2 nm can be easily produced.
While the invention has been described by reference to various embodiments, it will be understood that modification changes may be made without departing from the scope of the invention which is to be defined only by the appended claims and their equivalents.
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In order to tune the frequencies of radiation sources, a frequency locker is provided having equally spaced periodic frequencies with a spectral range substantially equal to the frequency spacing of a plurality of radiation sources with equally spaced apart frequencies. The periodic frequencies of the locker are slightly offset from those of the radiation sources. Radiation from each of the sources is passed through the locker and the radiation passed by the locker is detected and used to adjust the frequencies of the sources in order to tune the sources. The frequency locker includes an etalon with dimensions accurate to 0.5 microns or better. The dimension of the etalon may be controlled by controlling the thickness of spacers for maintaining vacuum or air gaps where the dimensions may be altered by thin film deposition and etching techniques. The optical path length of the etalon may also be changed by altering the angle of incidence of an incoming beam with the reflective surfaces of the etalon.
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FIELD OF THE INVENTION
The invention belongs to the field of hydrobiological cell and the field of diseases prevention and control in aquiculture, and particularly relates to cyprinid herpesvirus II-sensitive brain tissue cell line of Carassius auratus gibelio , an establishing method of the cell line and uses of the cell line.
BACKGROUND OF THE INVENTION
Cyprinid herpesvirus II (CyHV-2), also known as Herpesviral haematopoietic necrosis virus (HVHN) or Goldfish haematopoietic necrosis virus (GFHNV) is classified as a member of the genus Cyprinivirus , the family Alloherpesviridae, together with the other two Herpesviruses of Cyprinid fish family, CyHV-1 (Carp pox) and CyHV-3 (Koi herpesvirus, KHV). CyHV-2 was first reported in 1995 to cause huge economic losses to goldfish culture in western Japan from 1992 to 1993 and the mortality for the infected goldfish was as high as 100%, followed by reports of a successive outbreaks of such disease in other countries and regions. In the spring of 1997, a large number of deaths occur in the US west coast for circulating aquaculture juvenile goldfishes, and the mortality was up to more than 80%, which was confirmed later by CyHV-2 infection. The international trade of ornamental fish is largely contributed to the global spread of the disease, and soon afterwards, the disease outbreaks successively in cultured goldfishes in Taiwan, Australia and the United Kingdom. In 2011, Hungary reported that CyHV-2 infection was also found in the cultured Carassius auratus gibelio . Since 2009, haematopoietic necrosis in crucian carp caused by CyHV-2 outbreaks in Jiangsu Province, China's major crucian carp culture areas. By mid-June 2012, an area of over 100,000 acres in the regions as Sheyang, Dafeng, Yandu, Baoying, Gaoyou, Xinghua, Hongze, Chuzhou in Jiangsu Province occurred disease, the mortality in the diseased ponds were up to 90%, and the economic losses has reached several hundred of millions. Meanwhile, in Hubei, Hunan, Jiangxi and Heilongjiang Provinces, CyHV-2 was also detected in the bodies of affected crucian carps. The virus has strong infectiousness and high mortality, causes huge economic losses to crucian carp and goldfish aquaculture, and seriously threatens to the development of crucian carp and goldfish aquaculture.
Cell culture and separation technique is the most accurate method in the diagnosis of virus disease, and it is usually recommended by the World Organization for Animal Health (OIE) as the preferred method for the detection of fish virus. However it has been found very difficult to proliferate CyHV-2 in common cell lines for the isolation of fish virus. Fathead minnow (FHM) cells, epithelioma popuasum cuprini (EPC) cells, eel kidney (EK-1) cells, chinook salmon embryo (CHSE-214) cells, rainbow trout gonad (RTG-2) cells and tilapia ovary (T0-2) cells are not sensitive to CyHV-2, only koi fin 1 (KF-1) cells can produce cytopathic effect (CPE). However, after three passages of the virus in KF-1 cells, CPE disappeared and no viral nucleic acid can be detected. Due to the lack of CyHV-2-sensitive cell lines, the study of CyHV-2 is limited, thus the establishment of a CyHV-2-sensitive cell line and study of its biological characteristics are of great significance to consecutive passage amplified culture of CyHV-2 and deep study of the characteristics of the virus. The present invention establishes a sensitive cell line GiCB for isolation and culture of cyprinid herpesvirus II. The application of the cell line includes but not limited to: development of physical and chemical properties, morphogenesis, virus infection approach, infection mechanism of cyprinid herpesvirus II and other fish viruses at molecular level; preparation, screen or evaluation of fish antiviral drugs.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a cyprinid herpesvirus II-sensitive brain tissue cell line of Carassius auratus gibelio . The cell line can be used for isolation, detection and culture of cyprinid herpesvirus II. The cell line was deposited in China Center for Type Culture Collection (CCTCC) under a classification of Gibel carp, Carassius auratus gibelio (GiCB) with an accession number of CCTCC NO: C2013179 on Nov. 29, 2013. Address: Wuhan University, Wuhan, China.
It is confirmed that the deposit of accession number CCTCC NO: C2013179 in China Center for Type Culture Collection (CCTCC) has been made under the Budapest Treaty. Furthermore, the materials deposited under accession number CCTCC NO: C2013179 in China Center for Type Culture Collection (CCTCC) will be irrevocably and without restriction or condition be released to the public upon issuance of a patent.
Another object of the present invention is to provide a method for establishing the cyprinid herpesvirus II-sensitive brain tissue cell line of Carassius auratus gibelio . The method is simple and easy to operate.
The final object of the present invention is to provide uses of the cyprinid herpesvirus II-sensitive brain tissue cell line of Carassius auratus gibelio . The cell line can be used for isolation, detection and culture of cyprinid herpesvirus II; and for the continuous passage and amplified culture of CyHV-2 and thus for the future study of the characteristics of the virus.
To achieve the above objects, the present invention provides the following technical solutions:
A method for establishing a cyprinid herpesvirus II-sensitive brain tissue cell line of Carassius auratus gibelio , comprising the steps of:
(1) Treatment of the brain tissue: removing the brain tissue of Carassius auratus gibelio under sterile conditions, and subjecting to sterile treatment to obtain tissue blocks of 50-100 mm 3 ;
(2) Primary culture: digesting the tissue blocks of step 1) with trypsin solution special for tissue separation for 10-15 min, shaking 3-4 times, adding an equal volume of culture solution special for brain tissue cells of Carassius auratus gibelio , pipetting uniformly, centrifuging and collecting the digested cells, removing supernatant, adding culture solution, pipetting cell pellets, culturing the obtained cell suspension in a culture flask for cells, and changing half amount of the culture solution every two days;
(3) Subculture: having grown the primary cultured brain tissue of Carassius auratus gibelio into a monolayer, adding 0.25% W/V trypsin solution and standing for 2 min, suspending the cells in a culture solution, subculturing by inoculating the cells in a way of one flask into two flasks; subjecting the cells to next passage culture according to the above subculture method after forming a cell monolayer again, to obtain a cyprinid herpesvirus II-sensitive brain tissue cell line of Carassius auratus gibelio , GiCB; the cell line of which being deposited in China Center for Type Culture Collection (CCTCC) under a classification of Gibel carp, Carassius auratus gibelio (GiCB) with an accession number of CCTCC NO: C2013179 on Nov. 29, 2013; Address: Wuhan University, Wuhan, China.
The brain tissue cell line of Carassius auratus gibelio GiCB is fibroblast-like cell. The optimal medium is M199. The optimal volume fraction of serum is 20% (V/V). The optimal culture temperature is 25° C. After the GiCB cells are frozen in liquid nitrogen and then recovered and stained, about 80% of the cells have cell activity and keep original growth tendency. The cells have been steadily subcultured to passage 65.
Said trypsin solution special for tissue separation is 0.5%-0.7% W/V trypsin solution; the cell culture and subculture is performed at a temperature of 25-28° C., pH 7.0-7.4.
Said culture solution special for brain tissue cells of Carassius auratus gibelio is M199 culture medium containing 10-20% V/V fetal bovine serum, 10-20 ng/ml human basic fibroblast growth factor, 10-20 ng/ml human epidermal growth factor, 100 U/ml penicillin, 100 μg/ml streptomycin, 0.25 μg/ml amphotericin B, pH 7.0-7.4.
Uses of the cyprinid herpesvirus II-sensitive brain tissue cell line of Carassius auratus gibelio , including use of the cell line for culturing cyprinid herpesvirus II; use of the cell line for detecting cyprinid herpesvirus II; use of the cell line for isolating cyprinid herpesvirus II; use of the cell line for preparing cyprinid herpesvirus II vaccines; use of the cell line for isolating and detecting other fish viruses; use of the cell line as a biological model for screening anti-cyprinid herpesvirus II drugs; use of the cell line for gene transfection of fish cells and study of gene functions.
Said cyprinid herpesvirus II is a wide virulent strain of cyprinid herpesvirus II or a known separated strain of cyprinid herpesvirus II.
By detecting the DNA of cyprinid herpesvirus II consecutively subcultured in the GiCB cells using nested PCR detection method, as a result, it is demonstrated that the viral nucleic acid is still detectable after consecutive subcultured to passage 6 in GiCB cells; Cytopathic effect (CPE) is stable and obvious; the cells having cytopathic effect are observed by ultrathin section under electron microscope, the result of transmission electron microscope shows that CyHV-2 virions and their replication process are found in the cells, demonstrating that CyHV-2 has good biological activity in the GiCB cells.
With regard to the suspected CyHV-2 clinical diseased samples to be detected, on the basis that the nested PCR assay is positive, the suspected diseased samples are inoculated with the established GiCB cell line of the present invention, only 12 days later cytopathic effects such as cell vacuolation, cell fusion and cell monolayer detachment can be observed; after the suspected CyHV-2 clinical diseased samples to be detected are subcultured for more than 5 passages, the presence of the virus still can be detected by nested PCR.
The present invention has the following advantages as compared with the prior art:
(1) It has been found by research that CyHV-2 is very difficult to proliferate in common cell lines for the isolation of fish virus. Fathead minnow (FHM) cells, epithelioma popuasum cuprini (EPC) cells, eel kidney (EK-1) cells, chinook salmon embryo (CHSE-214) cells, rainbow trout gonad (RTG-2) cells and tilapia ovary (T0-2) cells are not sensitive to CyHV-2, only koi fin 1 (KF-1) cells can produce cytopathic effect (CPE). However after three passages of the virus in KF-1 cells, CPE disappeared and no viral nucleic acid can be detected. The present invention establishes a CyHV-2-sensitive brain tissue cell line of Carassius auratus gibelio by separating and culturing the CyHV-2-sensitive brain tissue cells of Carassius auratus gibelio.
(2) By detecting the DNA of cyprinid herpesvirus II consecutively subcultured in the GiCB cells, the present invention demonstrates that the viral nucleic acid is still detectable after consecutive subcultured to passage 6 in GiCB cells. Cytopathic effect (CPE) is stable and obvious; when an ultrathin electron microscopic section is prepared from cells having the cytopathic effect, the result of transmission electron microscope shows that CyHV-2 virions and their replication process are be observed in the cells, demonstrating that CyHV-2 has good biological activity in the GiCB cells.
Based on the isolation, detection and culture of cyprinid herpesvirus II, the present invention establishes a CyHV-2-sensitive cell line GiCB, provides a necessary technical platform for isolation, identification, and study of the complete biological characteristics of CyHV-2, and lays a foundation for the prevention and control of hematopoietic necrosis of crucian carp and goldfish.
DESCRIPTION OF DRAWINGS
FIG. 1 is a schematic view of brain tissue cells of Carassius auratus gibelio GiCB at different passages; in FIG. 1 , A: primary brain tissue cells of Carassius auratus gibelio ; B: the 32nd passage brain tissue cells of Carassius auratus gibelio.
FIG. 2 is a schematic view of chromosomes and their number distribution of the 6th passage brain tissue cells of Carassius auratus gibelio.
FIG. 3 is a schematic view of brain tissue cells of Curassius auratus gibelio infected with CyHV-2; in FIG. 3 , A: normal GiCB cells as control; B: day 12 of the 1st passage GiCB cells infected with CyHV-2; C: day 12 of the 3rd passage GiCB cells infected with CyHV-2; D: day 12 of the 6th passage GiCB cells infected with CyHV-2.
FIG. 4 is a schematic view of nested PCR detection results of CyHV-2 from different culture passages. M: DL2000 Marker; Line 1: CyHV-2 histotoxicity control; Line 2: the 1 st passage CyHV-2 cytotoxicity cultured in GiCB cells; Line 3: the 2 nd passage CyHV-2 cytotoxicity cultured in GiCB cells; Line 4: the 3 rd passage CyHV-2 cytotoxicity cultured in GiCB cells; Line 5: the 4 th passage CyHV-2 cytotoxicity cultured in GiCB cells; Line 6: the 5 th passage CyHV-2 cytotoxicity cultured in GiCB cells; Line 7: the 7 th passage CyHV-2 cytotoxicity cultured in GiCB cells; Line 8: negative control.
FIG. 5 is a schematic view of electron microscope ultrathin sections of GiCB cells infected with the 5 th passage CyHV-2 cytotoxicity.
DETAILED DESCRIPTION OF THE INVENTION
The invention will be further described in detail below with reference to the particular examples. These examples are only illustrative and not intended to limit the present invention in any way. Various changes or modifications can be made without departing from the spirit and scope of the present invention, and these changes or modifications fall within the scope of the invention. Unless otherwise specified, the reagents used in the examples are purchased from biochemical reagent shops; and unless otherwise specified, the experimental techniques are conventional techniques.
Materials and reagents used in the particular examples of the invention:
1) Experimental Fish and Virulent Strain
Carassius auratus gibelio , about 50 g in weight, and about 12 cm in length, available from Yaowan experimental base of Yangtze Aquatic Research Institute, under Chinese Academy of Fishery Sciences, fed for one week before experiment. Cyprinid herpesvirus II, isolated and preserved by the our laboratory.
2) Main Reagents and Materials
M199 cell culture medium, Amphoterincin B, Penicillin/Streptomycin, Phosphoric acid buffer (PBS), trypsin-EDTA, Dimethyl Sulphoxide (DMSO), Colchicine, purchased from Sigma Company; Human basic fibroblast growth factor, Human epidermal growth factor, available from Peprotech Company; Fetal bovine serum, purchased from GIBICO Company; DNAzol nucleic acid extraction reagent, available from Invitrogen Company; rTaq enzyme, dNTPs for PCR, available from TaKaRa Company. Cell culture flasks, pipettes, freezing tubes, purchased from Corning Company; reagents and materials used for the preparation of Ultrathin section for transmission electron microscope, purchased from Beijing Zhongxingbairui Technology Co., Ltd.
3) Main Equipment and Instruments
Biological safety cabinet Class II (ESCO); Inverted microscope (Nikon); CCD camera (Nikon NIS Elements F530); Low-speed refrigerated centrifuge (3K15, Sigma); Thermostat incubator (Sanyo, MIR-153); Liquid nitrogen tank (MVE); Ultramicrotome (UC7, Leica); Transmission electron microscope (H-7650, Hitachi).
Example 1
Establishment of brain tissue cell line of Carassius auratus gibelio . The steps were as follows:
(1) Treatment of brain tissue: The brain tissue of Carassius auratus gibelio was removed under sterile conditions and placed in a culture dish, rinsed with PBS for 3 times, and cut into tissues blocks of 50-100 mm 3 with sterile ophthalmic scissors;
(2) Primary culture: the cut tissue blocks were placed in and digested with 0.5 W/V % trypsin solution at 28° C. for 15 min. Meantime, it was shaked for 3 times. After digestion, an equal volume of culture solution special for brain tissue cells of Carassius auratus gibelio (hereinafter called “culture solution” for short, the culture solution being M199 culture medium containing 20% V/V fetal bovine serum, 10 ng/ml human basic fibroblast growth factor, 10 ng/ml human epidermal growth factor, 100 U/ml penicillin, 100 μg/ml streptomycin, 0.25 μg/ml amphotericin B) was added and pipetted uniformly, followed by filtered once with 100 mesh nylon filter cloth. The filtrate was collected in a centrifuge tube, and centrifuged at 1500 rpm for 5 min to collect the cells treated by digestion and filtration. After removal of the supernatant, the cells were added with culture solution, pipetted uniformly, and filtered once with 300 mesh nylon filter cloth. The filtrate was collected and centrifuged at 1000 rpm for 5 min to collect the cell pellets; and then the culture solution was added to pipette the cell pellets. The obtained cell suspension was added in a 25 cm 2 cell flask and incubated at 25° C. Half amount of the solution was changed every two days.
(3) Subculture: After grew the primary cultured brain tissue of Carassius auratus gibelio into a monolayer, the original culture solution was removed and 2 ml 0.25 W/V % trypsin solution was added and placed still at room temperature for 2 min for digestion. The trypsin solution was removed and then 10 ml of culture solution special for brain tissue cells of Carassius auratus gibelio was added to spipette the cells at the bottom of the flask to obtain cell suspension, which was subcultured in a way by dividing the cells in one flask into two flasks. After a cell monolayer was formed again, the cells were subjected to next passage culture according to the above subculture method, until the cell line was established. After subcultured to passage 6, human basic fibroblast growth factor, human epidermal growth factor, penicillin, streptomycin and amphotericin B were no longer added to the culture solution special for brain tissue cells of Carassius auratus gibelio . The subcultured GiCB cells can cover about 80% of the bottom of the cell culture flask and formed confluent cell monolayer after about 2 or 3 days, and formed a dense cell monolayer after 5 days and then the next passage culture can be performed. As shown in FIG. 1 , A represented primary brain tissue cells of Carassius auratus gibelio ; B represented the 32 nd passage brain tissue cells of Carassius auratus gibelio.
The cell line was deposited in China Center for Type Culture Collection (CCTCC) under a classification of GiCB (Gibel carp, Carassius auratus gibelio ) with an accession number of CCTCC NO: 02013179 on Nov. 29, 2013; Address: Wuhan University, Wuhan, China.
Example 2
Biological characteristics of the brain tissue cell line of Carassius auratus gibelio , GiCB:
(1) Morphology: The cells are fibroblast-like cells.
(2) Growth properties: The passage GiCB cells began to adhere to the wall 30 min after subculture and completely adhered to the wall 8 h after subculture. The population doubling time was 50.5 h.
(3) Stability: The brain tissue cell line of Carassius auratus gibelio , GiCB, so far has been subcultured up to passage 65 and still grows in a stable proliferating status.
(4) Frozen storage and recovery:
After recovery, the GiGB cells adhered to the wall rapidly. The growth morphology, status was similar to the cells without frozen storage, and there was no significant difference. The recovered cells was stained with trypan blue and counted by cell statistics. About (80.38±5.10) % of the cells were not stained and had cell activities.
(5) Chromosome analysis
The 6 th passage brain tissue cell line of Carassius auratus gibelio , GiCB, was in the exponential growth phase. Colchicine was added with a final concentration of 20 μg/ml and incubated at 25° C. for 4 h and the cells were digested and collected, and treated with 0.075 mol/L KCl hypotonic solution for 25 min. Then pre-cooled carnoy's fluid was added and centrifuged at 1000 rpm for 5 min. After removal of the supernatant, it was fixed with carnoy's fluid for three times, 15 min each time. The sample was dropped on the slide by cold pendant drop method, after drying, it were stained with 5% Giemsa for 25 min, dried and then observed under a microscope. In the 100 observed cells at division phase, the 6 th passage cells derived from the brain tissue of Carassius auratus gibelio had a chromosome number of 212 ( FIG. 2 ), which was consistent with the characteristics of chromosomes of the artificial tetraploid Carassius auratus gibelio (Gui jianfang et al., Discovery of Multiple Tetraploids in Artificially Propagated Populations of Carassius Auratus Gibelio and Their Breeding Potentialities, Chinese Science Bulletin, 1992, 07:646-648; Gui jianfang et al., Preliminary Confirmation of Gynogenetic Reproductive Mode in Artificial Multiple Tetraploid Carassius auratus gibelio, Chinese Science Bulletin, 1992, 09: 836-838), namely including total 162 chromosomes of Carassius auratus gibelio and one genome of cyprinus carpio (50 chromosomes).
Example 3
The applications of the cyprinid herpesvirus II-sensitive cell line of Carassius auratus gibelio . The process was as follows:
(1) Collection and treatment of diseased sample infected with cyprinid herpesvirus II
kidney and spleen were collected from the diseased fish infected with cyprinid herpesvirus II that had just died, cut into pieces and homogenized with equal volume of PBS, centrifuged at 6000 rpm at 4° C. for 30 min, filtered through 0.22 μm membrane filter to obtain sterile tissue homogenate, packed and stored at −80° C. for use.
(2) Proliferation of cyprinid herpesvirus II in GiCB
After GiCB was cultured to 80% monolayer cells, the medium was removed and the cells were washed twice with PBS. 1 ml of the above treated diseased tissue homogenate supernatant was inoculated into the cell monolayer. Polybrene was added with a final concentration of 10 μg/μl and incubated at 25° C. for 2 h, during which the flask was slightly shaken every 15-20 min so as to attach uniformly. After the attachment, it was incubated with M199 maintenance medium replacement containing 2% serum at 25° C. Cytopathic effect (CPE) was observed day by day, and viruses were harvested when cytopathic effect reached 80%.
(3) Extraction and nested PCR detection of cytotoxic nucleic acid of cyprinid herpesvirus II
The significant cytopathic GiCB cells were frozen and thawed twice and then virus DNA was extracted with DNAzol reagent. The virus was detected according to the detection method for CyHV-2 by nested PCR.
PCR amplification conditions of outer primer P1: Primers:
CyHV-2P1F:
(SEQ ID NO: 1)
TGAAATGTCAAAAGTGGATGG;
CyHV-2P1R:
(SEQ ID NO: 2)
TATTCCCAGACAGCCTTCAAA.
Amplification conditions: pre-degeneration at 94° C. for 5 min, degeneration at 94° C. for 30 min, annealing at 55° C. for 30 min, extension at 72° C. for 40 s, 30 cycles; and 72° C. for 5 min;
PCR amplification conditions of inner primer P2: Primers:
CyHV-2P2F:
(SEQ ID NO: 3)
GAACACCGCTGCTCATCATC;
CyHV-2P2R:
(SEQ ID NO: 4)
ACTCTTCGCAAGTCCTCACC,
PCR amplification was performed using 1 μL of the amplified product of outer primer P1 as a template and inner primer P2 as a primer. The reaction conditions were the same as the first amplification. Meanwhile, positive control DNA template was used as a positive control and purified water was used as a negative control. The amplification product was identified by 2% (W/V) agarose gel electrophoresis.
(4) Observation of cyprinid herpesvirus II-infected GiCB by electron microscope
GiCB cells infected with the 5 th passage CyHV-2 cytotoxicity were fixed in 2% glutaraldehyde, postfixed in osmium tetroxide, dehydrated, embedded, cut into ultrathin sections, and stained with urangl acetate followed by lead citrate, then observed with transmission electron microscope.
(5) Results
After 10 days of inoculation of the GiCB cell monolayer with cyprinid herpesvirus II-infected diseased tissue homogenate, the cells became round or vacuolated, retracted, formed syncytium, and the cell gaps became large; 12 days later, GiCB cells fused and formed multinucleated giant cells, and cell monolayer were detached and produced threads, which were typical cytopathic effects (CPE); and CPE was stable after subcultured to passage 6 ( FIG. 3 ). However, no change was seen in normal cells.
DNA was extracted from different passages of CyHV-2 cell culture, and amplified by two cycles of PCR amplification to obtain a 357 bp fragment, which was identical to the amplified band of the positive control ( FIG. 4 ). The results were all determined as positive.
By observing the GiCB cells infected with the 5th passage CyHV-2 cytotoxicity through transmission electron microscope, a large number of mature CyHV-2 virions and their replication process can be observed, demonstrating that CyHV-2 had good biological activity in GiCB cells ( FIG. 5 ), which further demonstrated that the brain tissue cell line of Carassius auratus gibelio established by the present invention was sensitive to the virus, and can be used for the isolation, culture and detection of the virus. Meanwhile, it can be used as a cell model for study of the biological characteristics of cyprinid herpesvirus II, preparation of cyprinid herpesvirus II vaccine and screening of antiviral drugs.
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The present invention discloses a cyprinid herpesvirus II-sensitive brain tissue cell line of Carassius auratus gibelio and establishing method and use thereof. The cell line is deposited in China Center for Type Culture Collection under an accession number of CCTCC No: C2013179. The brain tissue cell line of Carassius auratus gibelio is in good growth state and sensitive to CyHV-2 that is presently hardly cultured with ordinary fish cell lines. After six passages of CyHV-2 in GiCB cells, viral nucleic acid can still be detected and a cytopathic effect is stable. When ultrathin microscopic sections are prepared from cells having the cytopathic effect, considerable mature CyHV-2 virions and their replication process can be observed in GiCB cells. The construction method of the brain tissue cell line of Carassius auratus gibelio of the present invention has high repeatability, scientific and reasonable conditions.
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TECHNICAL FIELD
[0001] The invention relates to a motor/pump aggregate, in particular to a motor/pump aggregate for a servo-steering system of a motor vehicle.
BACKGROUND OF THE INVENTION
[0002] In hydraulic systems, such as for example servo-steering devices used in motor vehicles, the energy providing components, in particular the motors and pumps, represent the main sources of noise, whereas the actuators of the systems only contribute a small amount to the overall noise. In a motor/pump aggregate of a servo-steering system including a motor unit and a pump unit with an outer housing surrounding the motor and pump units, in particular the outer surfaces of the outer housing emit noise to the exterior. Furthermore, in conventional motor/pump aggregates without particular sound-damping measures, the sound conducted through solids generated by the motor and pump units is passed on via the connected components into the passenger compartment and is emitted there as sound transmitted by air. The connected components can also be stimulated to natural oscillations, which in turn leads to the emission of sound transmitted by air.
[0003] In conventional motor/pump aggregates, to avoid vibrations, damping elements are arranged between the motor unit and the pump unit. However, this means a high expenditure in terms of construction technology and may lead to inaccuracy in the relative positioning and alignment of components of the motor and of the pump and also of the two components as a whole.
[0004] Thus, there is a desire for efficiently reducing the noise development in a hydraulic system with a motor/pump aggregate in a simple manner.
SUMMARY OF THE INVENTION
[0005] A motor/pump aggregate according to the invention comprises a motor/pump unit and an outer housing surrounding the motor/pump unit, the motor/pump unit including a motor unit and a pump unit, at least one part of the motor/pump unit being coupled to the outer housing by means of a damping bearing. The invention is based on the finding that the undesired emission and passing on of the noises generated by the motor/pump aggregate is best prevented in that the path of the conducting of sound through solids is interrupted or at least restrained as close as possible to the sound source. Through the invention, an acoustic uncoupling of the outer housing with respect to the motor/pump unit is achieved, so that the outer surfaces of the outer housing do not represent, or at least only represent to a small extent, emission surfaces for sound conducted through solids.
[0006] A passing of the sound conducted through solids on to vehicle components which are connected to the motor/pump aggregate can be prevented in that the damping bearing is coupled to a fastening part which is connected with the outer housing, the motor/pump aggregate being fastened in the vehicle by the fastening part.
[0007] In a first embodiment of the invention, the damping bearing comprises several damping elements disposed between the motor/pump unit and the outer housing. The damping elements are preferably constructed as plastic ribs. In this embodiment, the damping elements are substantially of parallelpiped shape. It proves to be particularly advantageous to align at least one damping element vertically and/or to align at least one damping element horizontally with respect to a longitudinal axis of the motor/pump aggregate, which defines a vertical direction. By means of the number, placing, alignment and the actual dimensions of the damping elements, the rigidity and the damping characteristics for guiding functions of the damping bearing, like the supporting of the weight forces of the components of the motor/pump unit and the supporting of acceleration moments of the motor of the motor/pump unit, can be optimized in line with specific objectives.
[0008] In a second embodiment of the invention, the damping bearing comprises an encircling damping element with respect to a longitudinal axis of the motor/pump aggregate. This damping element can seal a space between the outer housing and the motor unit from a space between the outer housing and the pump unit. In this case, the damping element undertakes the function of a dividing wall for the hydraulic fluid of the motor/pump aggregate, if for example only the pump unit is to have hydraulic fluid flowing around it.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 shows a perspective view of a motor/pump aggregate according to a first embodiment of the invention;
[0010] FIG. 2 shows a top view of the motor/pump aggregate of FIG. 1 without an upper housing part; and
[0011] FIG. 3 shows a diagrammatic side view, in section, of a motor/pump aggregate according to a second embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0012] The motor/pump aggregate 10 shown in FIG. 1 comprises a metallic outer housing 12 , which is illustrated so as to be transparent, in order to make visible the components situated therein. In the outer housing 12 , a motor/pump unit 14 is housed, which is composed of a motor unit 16 and of a pump unit 18 . The outer housing 12 serves to delimit a hydraulic fluid reservoir and is divided into a first housing part 20 surrounding the motor unit 16 and a second housing part 22 surrounding the pump unit 18 . The housing parts 20 , 22 are connected with each other by means of a fastening ring 24 , which also represents the mechanical connecting site to the vehicle body.
[0013] The motor/pump unit 14 is held in the outer housing 12 by a damping bearing which is formed from several damping elements 26 and 28 arranged between the motor/pump unit 14 and the fastening ring 24 (see also FIG. 2 ). The damping elements 26 , 28 are flat plastic ribs, substantially of parallelepiped shape, which are distributed over the outer periphery of the motor/pump unit 14 and the inner periphery of the fastening ring 24 . The damping elements 26 , 28 are vulcanized on the one hand to the inner periphery of the fastening ring 24 and on the other hand to a sheet metal ring 30 , which is shrunk onto a connecting plate 32 , on which both the motor unit 16 and also the pump unit 18 are fastened.
[0014] In relation to the illustration of FIG. 1 , in which the longitudinal axis A of the motor/pump unit 14 defines a vertical direction, hereinafter the damping elements 26 are designated as vertically aligned damping elements and the damping elements 28 arranged substantially perpendicularly thereto are designated as horizontally aligned damping elements. The vertically aligned damping elements 26 are rigid with respect to axial movements of the motor/pump unit 14 (down up and movements) and in particular support the inherent weight of the motor/pump unit 14 . The damping elements 26 are, however, flexible with respect to a rotation of the motor/pump unit 14 about the axis A relative to the outer housing 12 . The opposite occurs with the horizontally aligned damping elements 28 : these damping elements 28 are rigid with respect to a rotation, but flexible in axial direction. The damping elements 28 therefore provide for a support with respect to the acceleration and deceleration moments of the motor of the motor/pump unit 16 , the motor shaft of which is aligned parallel to the axis A. As can be seen in particular in FIG. 2 , in the illustrated embodiment, vertically and horizontally aligned damping elements 26 and 28 , respectively, alternate in peripheral direction.
[0015] The cooperation of all damping elements 26 , 28 provides as a whole for a damped, vibration-equalizing bearing of the motor/pump unit 14 in the outer housing 12 . The damping elements 26 , 28 separate the motor and the pump as noise sources from the emitting outer surfaces of the outer housing 12 .
[0016] In the embodiment shown in FIG. 3 , the motor/pump unit 14 is held by means of a diagrammatically illustrated, encircling damping element 34 . The encircling damping element 34 can be constructed so that it is impermeable to the hydraulic fluid surrounding the pump unit 18 . In this case, the space between the lower housing part 20 and the motor unit 16 is kept free of hydraulic fluid. The damping element 34 can, however, also be arranged or constructed so that it is permeable to the hydraulic fluid. This is suitable when the motor is a wet-running motor and a cooling of the motor unit 16 by the hydraulic fluid is desired.
[0017] The damping bearings described above are also advantageous for motor/pump aggregates in which the motor unit and the pump unit are connected with each other by an intermediate housing. In this case, the damping bearing is coupled to the intermediate housing. Therefore, with only one damping bearing the entire motor/pump unit can likewise be uncoupled from the outer housing, so that the excitations of sound conducted through solids of the individual components, in particular of the motor unit and of the pump unit, do not need to be damped separately. In other embodiments of the motor/pump aggregate, however, also several damping bearings can be provided, for example a bearing for the motor unit and a separate bearing for the pump unit.
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A motor/pump aggregate ( 10 ), in particular for a servo-steering system of a motor vehicle, includes a motor/pump unit ( 14 ), and an outer housing ( 12 ) surrounding the motor/pump unit ( 14 ). The motor/pump unit ( 14 ) includes a motor unit ( 16 ) and a pump unit ( 18 ). At least one part of the motor/pump unit ( 14 ) is coupled to the outer housing ( 12 ) by means of a damping bearing.
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FIELD OF THE INVENTION
The present invention relates to the field of retail drug sales boxes containing a plurality of individual doses of medicine, such as over the counter medicines.
BACKGROUND OF THE INVENTION
In drug stores, convenience stores, grocery stores or other retailers selling small quantities of non-prescription drugs, a display device is usually used to display one or two packets of a pain reliever, for example. Small quantities of other medicines or bandages, may be displayed by the display device.
However, when displaying a box of a non-prescription medicine, for example, the box is usually hung from a rod or peg extending from a display board, such as a peg board, at the retail location. A consumer will customarily remove the box from the display device to review the information contained on the box of medicine prior to its purchase.
The repeated removal and re-hanging of a display box can prove to be detrimental to the hanging tab extending from the display box. Therefore, the usually single sheet of paper board, including the hanging portion for the display box, is often times ripped by repeated consumer review. Attempts to fix the broken hanging tab with tape or staples may be functionally acceptable but aesthetically displeasing to the consumer.
Accordingly, there is a need to reinforce display packages hanging on a support rod.
SUMMARY OF THE INVENTION
It is an object of the present invention to overcome the deficiencies of prior practices by the incorporation of a four-ply paper board hanging hole in a display box for hanging a display box from a support rod. This is accomplished by the use of a paper board die blank having a hanging hole in four layers of the box such that, when the box is assembled, the four hanging holes are aligned to provide a strongly reinforced hanging hole which proves quite difficult to rip. Therefore, an increased aesthetic appearance of the display box is achieved, resulting in increased sales and minimal wasting of display box products.
This object is also achieved by a display box formed of a single sheet of paper board die cut into a series of interconnected panels with fold lines. The box includes a front panel with a top portion and a vertical extension portion and a rear panel interconnected to the front panel by side panels. The vertical extension portion of the front panel interconnects the front panel and the rear panel at least for a portion of the front panel. Both the front panel and the rear panel include parts of a bottom panel with the front panel including an upper support portion of the bottom panel and the rear panel including a lower portion of the bottom panel. The lower portion of the bottom panel includes adhesive for securing to the upper support portion of the bottom panel.
Secured along the intersection of a side panel and the rear panel is a drug facts panel. The drug facts panel is pivotally mounted along the intersection of the side panel and the rear panel and includes a front panel portion and a rear panel portion. The front panel portion and the rear panel portion are adhered to each other and each include a hanging hole. In addition, the rear panel and the front panel include a hanging hole so that, when the display box is assembled, there are four layers of paper board forming a single aligned hanging hole.
In addition, the rear panel includes a die cut flap providing access to the interior of the box cavity. The perforations forming the access flap are cut from the rear panel to pivotally mount the access flap along a side edge of the box formed at the intersection of the rear panel and the opposite side panel from the side panel to which the drugs facts panel is pivotally mounted. The access flap includes a finger slot which is used to reach into the box cavity and pull the access flap out from the rear panel, pivoted about the side edge of the box, to gain access to the interior of the box.
After product is removed from the interior of the box, the access flap is folded down to lay flat in alignment with the rear panel. The drugs facts panel is then closed on top of the rear panel and by the use of glue dots, the rear panel is secured to the drugs facts panel.
By the movement of the access flap, and the return of the access flap into alignment with the rear panel, all drug information/packaging graphics of the rear panel remain intact. The information desired to be conveyed to the consumer is still readily available. This is in contrast to prior designs of packaging where to gain access to the interior of the packaging, the integrity of the packaging is destroyed and the valuable consumer information displayed on the exterior of the packaging is damaged. The consumer can therefore no longer take advantage of the information and potential warnings contained on the packaging for ready reference. The packaging may also be discarded by the consumer because the packaging cannot easily be re-sealed.
Accordingly, it is an object of the present invention to provide a drug delivery box having four layers of paper board at the hanging hole.
It is another object of the present invention to provide a drug dispensing box having four layers of paper board at the hanging hole and having a drugs facts panel pivotally mounted to a rear edge of the box.
It is still yet another object of the present invention to provide a drug dispensing box having four layers of paper board at the hanging hole and having a drugs facts panel pivotally mounted to a rear edge of the box and having an access flap in a rear panel of the box for gaining access to an interior of the box.
It is still yet another object of the present invention to provide a drug dispensing box having four layers of paper board at the hanging hole and having a drugs facts panel pivotally mounted to a rear edge of the box and having an access flap in a rear panel of the box for gaining access to an interior of the box, the access panel being pivotally mounted to a rear edge of the box for return to alignment with the rear panel of the box and sealing by the drug facts panel.
These and other objects of the invention, as well as many of the intended advantages thereof, will become more readily apparent when reference is made to the following description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The following drawings illustrate examples of various components of the drug display box disclosed herein, and are for illustrative purposes only. Other embodiments that are substantially similar can use other components that have a different appearance.
FIG. 1 is a perspective view of the drug delivery/display box of the present invention hanging from a peg at a retail location.
FIG. 2 is a front view of the drug delivery/display box.
FIG. 3 is a rear view of the drug delivery/display box.
FIG. 4 is a left side view of the drug delivery/display box.
FIG. 5 is a right side view of the drug delivery/display box.
FIG. 6 is a top view of the drug delivery/display box.
FIG. 7 is a bottom view of the drug delivery/display box.
FIG. 8 is a cross-sectional view taken along line 8 - 8 of FIG. 1 .
FIG. 9 schematically illustrates the die lines of the interior of the drug display box of the present invention formed of a single sheet of paper board.
FIG. 10 is an exterior view of the die lines of the drug display box.
FIG. 11 is a perspective view illustrating the drug facts panel pivotally mounted to a rear panel of the drug display box.
FIG. 12 is a perspective view illustrating the fully opened position of the pivoted drug facts panel pivotally mounted on the rear panel.
FIG. 13 is a rear perspective view of the drug facts panel pivotally mounted on the drug display box and exposing the access flap pivotally mounted from a rear edge of the rear panel.
FIG. 14 illustrates the pivoting of the access flap to gain access to at least one of a plurality of packages of medicine with the access flap being movable into the plane of the rear panel and being covered by the drug facts panel.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In describing a preferred embodiment of the invention illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. However, the invention is not intended to be limited to the specific terms so selected, and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar purpose.
With reference to the drawings, in general, and FIGS. 1-8 , in particular, a drug delivery/display box embodying the teachings of the subject invention is generally designated as 20 . With reference to its orientation in FIG. 1 , the drug display box includes a front panel 22 including a top portion 24 and upstanding portion 26 . The top portion 24 extends rearwardly from front edge/fold line 28 and to rear edge/fold line 30 . Upstanding portion 26 is folded at a right angle at edge 30 with respect to top portion 24 . The top portion 24 extends laterally between right side panel 32 and left side panel 34 .
Upstanding portion 26 includes a hanging hole 36 . The particular shape of hanging hole 36 may be altered to include a triangular shape or any other shape used for hanging a drug display box from a rod 38 by passing a leading end 40 of the rod through the hole 36 .
With reference to FIG. 1 , a rear panel 42 , extending the combined height of the front panel 22 and upstanding portion 26 , extends in a plane parallel to the front panel 22 and upstanding portion 26 and engages the upstanding portion 26 . The rear panel 42 is spaced from the front panel 22 by a distance equal to the extension of top portion 24 between fold lines 28 and 30 .
Extending parallel to rear panel 42 is a drug facts panel 44 including a rear panel portion 46 as shown in FIG. 3 . As shown in FIGS. 4 , 5 and 8 , a front panel portion 48 is glued to rear panel portion 46 to form the drug facts panel 44 pivotally mounted to a side edge of the drug display box.
As shown in FIG. 8 , the hanging hole 36 of upstanding portion 26 is in alignment with the hanging hole 50 of rear panel 42 and the hanging hole of drug facts panel 44 including the hanging hole 52 of front panel portion 48 and the hanging hole 54 of rear panel portion 46 . The four aligned hanging holes provide greatly increased strength for supporting the drug display box of the present invention for numerous incidents of removal and re-replacing of the drug display box on a support rod 38 .
As shown in greater detail in FIGS. 9 and 10 , the layout of a single piece of paper board is shown which is used to form the drug display box of the present invention. In FIG. 9 , the rear panel 42 is shown connected to side panel 32 by fold line 60 . At an opposite edge, fold line 62 connects to side support panel 64 . The opposite side of side support panel 64 , as shown in FIG. 10 , includes an adhesive surface 64 a covered by a piece of removable tape for forming the display box.
Located between side panel 32 and side support panel 64 is bottom panel 66 having adhesive layer 68 . Bottom panel 66 is separated from rear panel 42 by fold line 70 .
Front panel 22 , in addition to top portion 24 and upstanding portion 26 , includes a bottom support panel 72 connected to front panel 22 by fold line 74 . The bottom support panel 72 will sit on top of bottom panel 66 , as shown in FIG. 8 , to reinforce the bottom of the display box.
The side panel 32 is connected to front panel 22 by fold line 76 , whereas side panel 34 is connected to front panel 22 by fold line 78 . Both of the side panels 32 and 34 include fold flaps 32 a , 32 b and 34 a , 34 b , respectively.
The drugs facts panel 44 is formed by folding front panel portion 48 along fold line 82 onto rear panel portion 46 such that the glue strip areas 80 are engaged by front panel portion 48 to secure the front panel portion 48 to rear panel portion 46 and align the hanging holes 52 and 54 . The rear panel portion 46 is pivotally connected to the side panel 34 by fold line and edge 84 .
As shown in FIGS. 9 and 10 , the rear panel 42 includes a perforation line 90 having sections 90 a , 90 b and 90 c . The perforation line 90 forms access flap 92 pivotally mounted along fold line 60 to side panel 32 . A finger hole perforation line 94 is cut to gain access to the interior of the box when the finger hole tab 96 is removed by breaking the perforation line 94 .
With reference to FIG. 10 , the printing of the required drug use information and all other indicia is achieved by a single sided printing. This reduces the cost of production and increases the efficiency of production.
The display box of the present invention is formed by folding front panel portion 48 onto rear panel portion 46 and securing the two panel portions together to form the drug facts panel. The two side panels 32 , 34 are then folded perpendicular to the front panel 22 along fold lines 76 , 78 , respectively. The flaps 32 a , 32 b and 34 a , 34 b are folded inwardly to form support surfaces.
The rear panel 42 is then folded along fold line 60 to lie parallel to front panel 22 by a separation distance equal to the width of side panels 32 or 34 . The adhesive 64 a on side support panel 64 is then brought into engagement, after folding along fold line 62 , with the underside of side panel 34 . A rectangular-shaped box is thereby formed.
Bottom support panel 72 is folded along fold line 74 and thereafter bottom panel 66 is folded to engage its adhesive surface 68 with the bottom support panel 72 to form the bottom of the box. Finally, the top portion 24 is folded along fold line 28 to extend parallel to the bottom panel 66 and the upstanding portion 26 is folded along fold line 30 to extend parallel to the rear panel 42 and adhere the upstanding portion 26 by glue strips 98 to the rear panel 42 . The four hanging holes 36 , 50 , 52 and 54 are aligned in successive order to form a four layer supportive hanging hole.
With reference to FIG. 11 , the drug facts card 44 is shown pivoted away from the rear panel 42 . In this position, and the position shown in FIGS. 12 and 13 , viewing of the indicia written on the rear panel portion 46 , the front panel portion 48 and the rear panel 42 is possible. This indicia provides important information on the use and directions for use of the medication included in the display box.
As shown in FIG. 13 , the front panel portion 48 includes a glue dot 100 , as shown by a circle, with a corresponding complimentary located glue dot 102 located on the rear panel 42 . The front panel portion 48 and the rear panel 42 are thereby releasably secured or interconnected to prevent inadvertently moving the front panel portion 48 away from the rear panel. When moving the front panel portion 48 into engagement with the rear panel 42 , the alignment of the front panel portion 48 and the rear panel 42 in parallel overlying orientation is maintained.
As explained with reference to FIG. 9 , perforation line 90 is accessible when the front panel portion 48 is moved away from the rear panel 42 . As shown in FIG. 14 , after removal of the finger hole tab 96 along perforation 94 , it is possible to pivot the access flap 92 about fold line 60 to provide access to the interior 104 of the box.
Housed within the box may, for example, be located two single dose medicine packages 106 and 108 . Access is provided to the medicine packages by pivoting of the access flap 92 . One of the medicine packages may be removed from the interior 104 of the box and the access flap 92 returned to an orientation in the plane of rear panel 42 . Thereafter, the front panel portion 48 may be moved to overlie the rear panel 42 , thereby securing the closure of the access flap 92 , preventing access to the interior 104 of the box.
With the access flap 92 returned to the plane of the rear panel 42 , substantial portions of the indicia would still be in a readable format. The integrity of the packaging being maintained, repeated use of the packaging by the consumer is available for subsequent use of any additional stored medicine contained in the interior 104 of the package.
The foregoing description should be considered as illustrative only of the principles of the invention. Since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and, accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.
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A four-ply paper board hanging hole in a display box for hanging a display box from a support rod. This is accomplished by the use of a paper board die blank having a hanging hole in four layers of the box such that, when the box is assembled, the four hanging holes are aligned to provide a strongly reinforced hanging hole which proves quite difficult to rip. Therefore, an increased aesthetic appearance of the display box is achieved, resulting in increased sales and minimal wasting of display box products.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is the U.S. national phase of international application PCT/AU2016/000038 filed Feb. 13, 2016 which designated the U.S., and claims the priority of Australian patent application No. 201 5900469 filed Feb. 13, 2015, the entire contents of both of which are hereby incorporated by reference.
TECHNICAL FIELD
[0002] The present invention is directed extruded aluminum members which are comprised of parts that snap fit together without requiring any screws or rivets. Such members can be used in the construction of assemblies such as post and rail fences, fence panels and balustrades and the like to improve ease of manufacture and installation.
BACKGROUND OF THE INVENTION
[0003] Any references to methods, apparatus or documents of the prior art are not to be taken as constituting any evidence or admission that they formed, or form part of the common general knowledge.
[0004] Aluminum panels comprising spaced apart post members and an array of spaced apart parallel slat members which are snap fitted together without separate fasteners are quite common and find popularity due to their aesthetic appeal, clean lines, and resistance to weathering and corrosion. Popular uses for such panels include fence panels and screens.
[0005] Australian patent application 2006230672 illustrates a known type of snap together aluminum panel. This panel comprises unitary post members into which slots are cut and edges of slat members pass into the slots. The slats are held in the posts by clamping legs/fins. The post and clamping legs are formed as a single piece typically by extrusion.
[0006] This type of panel assembly suffers from a number of disadvantages. One disadvantage is in the increase cost of manufacture of the post containing the cutouts. The cutouts are formed using a computer controlled cutting machine such as a CNC router. This is a complex and relatively expensive manner in which to provide cutouts.
[0007] Another disadvantage is that the clamping legs/fins can lose their memory over time. The reason for this is that the “hinge” part of the legs comprises the area where the legs extend from an inner wall of the post, and this area (the hinge area) is relatively small and therefore more likely susceptible to fatigue over time. Should this occur, the slats can move or slip or begin to rattle and it may be necessary to replace the entire post.
[0008] Another disadvantage with this type of panel is that it is quite difficult to fit the panel into a desired position. For example, panels may be required to be located between brick or block uprights. In that case the panels need to be fastened to the uprights using masonry anchors or something similar. The design of the panel is such that an internal masonry anchor cannot be used as there is no access to the internal back wall of the panel post. Thus, external brackets may need to be used which can be unsightly. Alternatively, a masonry anchor can be drilled entirely through the post which leaves a visible anchor point which is also unsightly.
[0009] Another disadvantage is that if there is any damage to a particular slat, it becomes necessary to remove the entire post from the brick or block uprights (for example). Refitting of a new post can be time-consuming and may require drilling of new openings in the uprights.
[0010] There is a need for improved snap-fit members which are composed of at least two parts that can be fastened together readily for use in the construction of assemblies such as fences, fence panels, balustrades and the like and which can overcome at least some of the above-mentioned disadvantages or which can provide a commercial choice in the marketplace.
SUMMARY OF THE INVENTION
[0011] According to a first aspect of the present invention there is provided a post comprising:
[0012] a base member and a cover member having corresponding snap fit formations by which the base member and the cover member are fastened to each other,
[0013] the cover member including an end wall with first and second buttressing walls projecting therefrom,
[0014] the base member comprising a base wall with first and second clamping legs extending therefrom for clamping a third member therebetween, the clamping legs converging outwardly and inwardly from the base wall to present a minimum space therebetween;
[0015] at least one opening formed through the base wall or the end wall for passage of a third member therethrough;
[0016] wherein the third member is oversized relative to the minimum space between the first and second clamping legs whereby forcing the third member through the minimum space urges portions of the clamping legs against walls of the cover member to thereby assist in retaining the cover member fast with the base member.
[0017] In a first embodiment of the invention the buttressing walls comprise sidewalls that extend over opposed sides of the base member. In this embodiment the at least one opening for passage of the slat is formed through the cover member. In this first embodiment the snap fit formations comprise inwardly projecting lips formed along the opposed sidewalls and corresponding rebates formed along outer edges of the base wall.
[0018] In a second embodiment of the invention the base wall further includes first and second sidewalls extending from opposed sides of the base walls with the first and second clamping legs being located between the first and second sidewalls.
[0019] Preferably, in the second embodiment remote ends of the first and second sidewalls are snap fitted to opposed sides of the cover.
[0020] It is preferred that in the second embodiment the buttressing walls and the clamping legs have portions that snap-fit together. For example, the clamping legs may be formed with outwardly disposed first grooves that receive corresponding inwardly projecting first lips of the buttressing walls.
[0021] Preferably the first and second clamping legs terminate in respective tapering portions to assist in guiding the third member there between in use. It is also preferable that the first and second clamping legs be formed with second outwardly disposed grooves that engage with corresponding inwardly projecting second lips of the buttressing walls during clamping of the third member.
[0022] In a third embodiment of the present invention first and second lateral wings extend from distal ends of the first and second sidewalls wherein outer edges of the lateral wings are formed with snap fit formations for receiving a balustrade or other cover. The snap fit formations may include a slot having a side formed as an undercut adjacent a tapering ridge whereby the tapering ridge assists in installing an edge of a balustrade into the slot.
[0023] A post arrangement according to an embodiment of the invention, such as that illustrated in FIGS. 1 and 2 provides several advantages. Firstly, fitment of the panel to a surround is straightforward in that the base member can be easily screwed or otherwise fastened to the surround prior to attachment of the cover member. Secondly, if a slat is damaged and needs to be replaced, the slat and the cover member can be removed while keeping the base member fixed to the surround. That is, it is no longer necessary to remove the entire post to replace a slat. Thirdly, the openings in the cover member (through which the slats pass) no longer need to be routed or otherwise cut through the cover member using expensive machinery. Because the cover member can be substantially U-shaped or C shaped, a simple punch die can be used to form the openings as both sides of the interconnecting wall are now available for the punching operation. Fourthly, by having the clamping legs forming part of (and typically essentially the entire) side wall of the base member, the “hinge area” is much more robust and there is much less likelihood of fatigue and loss of memory.
[0024] Another advantage of the post according to the present invention is that the base member profile can remain the same for slats of different sizes as all that is required is to provide a different cover member with larger or smaller openings (depending on the size of the slats) and which can be snap fitted to the base member.
[0025] Another advantage is that should there be damage to a clamping leg on the base member; the base member can be replaced without requiring replacement of the entire post.
[0026] In another form, the invention resides in a panel comprising at least one post as described above and at least one slat.
[0027] Throughout the specification, the term “panel” will be used to include but not limited to fencing, gates, awnings, window screens, other types of screens, and fixed louvres.
[0028] The term “post” is meant to be interpreted broadly and to include any type of elongate member to which slats or other members can be fitted. The post may be positioned substantially vertically in use, substantially horizontally in use, or possibly at some other angle. The post may be an end post or an intermediate post.
[0029] The post will typically be formed of aluminum and typically from extruded aluminum as this is a common process. However, there may be circumstances where the post is made from materials other than aluminum such as plastics, or from metals other than aluminum, or from laminate materials and the like. If the post is formed from aluminum, the aluminum may be treated for corrosion resistance and the treatment may include anodizing, powder coating, painting and the like.
[0030] The length of the post can vary, typically, depending on the size of the panel to be formed. It is envisaged that the usual length of the post will be between 40 cm (for instance a screen for a small toilet window) up to 2 or 3 m for a larger fence screen. The post may comprise a single post member or may comprise a number of post members connected together by any suitable means. For instance, the post members may be connected using an internal sleeve type fixing, or an external socket type arrangement or using fasteners or welding and the like. If post members are to be connected together, it is highly preferred that this is done in an aesthetically pleasing manner.
[0031] The post will typically be formed from two parts being the base member and the cover member and that can be snap fitted together.
[0032] The base member may be of any suitable length and width and have any suitable thickness depending on the size and shape of the panel to be formed and whether the panel will subject to high wind loading, twisting or other types of forces on the panel. It is envisaged that the base member will have a width and a depth of between 10 mm up to 200 mm. Similarly, it is envisaged that the wall thickness of the base member (depending on material) will be between 1-10 mm.
[0033] The base member will typically be substantially U-shaped comprising a base wall and a pair of upstanding sidewalls. However, there may be circumstances where the channel member may have a curved base wall. There may be circumstances where the base wall may have other configurations, inter alia, for aesthetic reasons, for functional reasons (for instance the post may be used as balustrading) or for fitment reasons (for instance the support may include a recess or rebate in which the base wall fits).
[0034] The sidewalls preferably have a width which approximates the width of the sidewalls of the cover member such that when the base member is attached to the cover member, the sidewalls extend substantially through the cover member towards the base wall of the cover member. This can improve the clamping action to the slats since the side walls of the cover member may act as buttresses or buttress walls and assist in holding the clamping legs of the base member firmly against the slat.
[0035] The clamping leg may comprise a turned in portion of each side wall. It is preferred that substantially the entire side wall assists in the clamping action against the slat and this will be described in greater detail below. There may be circumstances where each side wall contains more than one turned in portion and may be circumstances where only one side wall contains a turned in portion.
[0036] The end wall of the cover member is formed with a plurality of openings through which the end of slats can pass. Because the cover member can comprise a simple U-shaped type profile, it is possible to form the openings using a simple punch die which greatly improves manufacturing speed and reduces manufacturing cost. The number of openings will depend on the number of slats that are to be accommodated. The shape of the openings will depend on the shape of the slats that are to be accommodated. It is envisaged that the openings will be substantially identical or, for decorative or strength purposes, some openings may be larger or smaller than others to provide a panel having larger and smaller slats.
[0037] Some form of snap fitting means is provided on the base member and/or the cover member to enable these parts to be snap fitted together. In one form, the snap fitting means may comprise small turned in lips on the cover member which engage into small rebates or recesses on the base member. Alternatively, the base member may be formed with small turned in lips and the cover member may be formed with small rebates or recesses.
[0038] The slats will typically comprise extruded aluminum members. Such members are well-known. These members are usually substantially hollow. It is however possible for the members to be filled with foam or other material to improve strength properties, insulation properties, sound deadening properties and the like. The slats may also comprise materials other than aluminum. For instance, the slats may be formed from solid or hollow plastics. It is envisaged that the slats may also comprise wood or wood laminate slats. The slats may comprise a number of smaller parts attached together to form the slat. The slat may be formed from laminated material or other built-up materials. It is envisaged that the slats may also be formed from a grid like or mesh like material to provide security and ventilation. The slats may be formed from substantially clear material. It is also envisaged that the slats may have end brackets or end pieces adapted to pass into the openings on the post.
BRIEF DESCRIPTION OF THE DRAWINGS
[0039] Preferred features, embodiments and variations of the invention may be discerned from the following Detailed Description which provides sufficient information for those skilled in the art to perform the invention. The Detailed Description is not to be regarded as limiting the scope of the preceding Summary of the Invention in any way. The Detailed Description will make reference to a number of drawings as follows:
[0040] FIG. 1 . Illustrates an exploded view of a panel containing slats and a post according to an embodiment of the invention.
[0041] FIG. 2 . Illustrates a section view of a post according to the embodiment of the invention and an attached slat.
[0042] FIG. 3 . Is a top view of a fence comprising a slat and posts according to a further embodiment of the present invention.
[0043] FIG. 4 Is an exploded isometric view of the fence of FIG. 3 .
[0044] FIG. 5 Is an exploded isometric view of a fence according to a further embodiment of the present invention.
[0045] FIG. 6 Is an isometric view of a portion of a post of the fence of FIG. 5 according an embodiment of the present invention.
[0046] FIG. 7 Is an end view of the post of FIG. 6 illustrating the engagement of the two portions of the post.
[0047] FIG. 8 Is an end view of a narrower version of the post of FIG. 7 showing the two parts prior to their engagement together.
[0048] FIG. 9 Is an end view of the post of FIG. 8 subsequent to the engagement of the two parts of the post.
[0049] FIG. 10 Is an isometric, exploded view of a post and rail fence according to a further embodiment of the present invention.
[0050] FIG. 11 Is a top plan view of the post of FIG. 10 .
[0051] FIG. 12 depicts a balustrade assembly according to an embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0052] Referring now to FIGS. 1 and 2 , these illustrate an embodiment of the invention which comprises a specially designed two-part post which overcomes the number of disadvantages with existing fit together panels. The various posts that will be described according to embodiments of the invention make use of “snap fit” joints. A snap fit or “snap lock” or sometimes as it is called a “press fit” joint is a joint which is self-locking and which requires no additional fasteners such as screws or rivets to hold the joint together. The mating parts of a snap-fit joint exert a cam action on each other, flexing until one part slips past a raised lip on the other part. Once past this lip, the flexed parts snap back to their normal shape and the lip prevents them from separating. Once snap fitted together the joint cannot usually be unintentionally dissembled.
[0053] The post 15 comprises a base member 17 and a cover member 16 . In the embodiment, each of these is formed from extruded aluminum. Cover member 16 is substantially C shaped and comprises a base wall 18 and a pair of sidewalls 19 this being best illustrated in FIG. 2 . The outer edge of each side wall 19 contains a small turned in lip 20 which forms part of the snap fitting means and which will be described in greater detail below.
[0054] Base wall 18 (see FIG. 3 ) is formed with a number of punched out openings 21 to accommodate edges of slats 22 .
[0055] Base member 17 is similar to cover member 16 in that it is also substantially U-shaped or C shaped and comprises a bottom wall 24 (see FIG. 4 ) and opposed sidewalls 25 . Base member 17 is sized to fit within cover member 16 , or put differently, cover member 16 can snap fit over the sidewalls 25 of base member 17 . The peripheral edge of bottom wall 24 contains a small rebate 26 which forms the other parts of the snap fitting means such that the cover member 16 can be snapped over base member 17 by the turned in lips 20 on cover member 16 engaging against the rebate 26 on the peripheral edge on bottom wall 24 of base member 17 . It can be seen that cover member 16 can substantially conceal base member 17 to provide an aesthetically pleasing effect.
[0056] The sidewalls 25 of each base member 17 are shaped to converge towards an apex 27 and thence to diverge outwardly and away from each other. The apex 27 comprises a turned in portion which forms a clamping leg on each side wall 25 . The opposed turned in portions function to clamp a slat therebetween. The sidewalls 25 diverge outwardly from the turned in portion 27 to the outermost edge 28 of each side wall. The diverging portions of the sidewalls 25 facilitate entry of a slat 22 .
[0057] A slat 22 can be pushed through one of the openings 21 in cover member 16 . As the slat passes through the opening 21 will be guided by the diverging portion to push against the turned in portion 27 and to push these portions outwardly as the thickness of the slat “T” is greater than the distance “X” between the turned in portions. This causes the slat to be securely clamped between the sidewalls 25 which comprise clamping legs.
[0058] The entire side wall 25 can form the clamping leg with the turned in portion forming the contact area and the remainder of the side wall providing the required bias or clamping force. As the side wall is turned in from the bottom wall 24 , this provides a good reliable and long-lasting “memory” to each clamping leg.
[0059] The slat is usually pushed through the opening 21 such that the edge of the slat sits against or closely spaced from the bottom wall 24 such that each turned in portion 27 can properly clamp against a respective side wall of slat 22 and at a position spaced some distance from the edge of the slat.
[0060] A panel can be easily snap fitted together by providing a pair of posts 15 and inserting the slats into the openings on each post 15 with the slats being clamped in place between an adjacent pair of clamping legs 27 . The base member 17 can be screwed or otherwise attached to a supporting post (if required) and the cover member 16 can then be snapped fitted to the base member to provide an aesthetically pleasing finish and completely concealing all the fixing screws to the supporting post. A damaged slat 22 can be removed by uncapping cover member 16 and it is not necessary to remove base member 17 . Different types of cover member 16 can be attached to a common base member 17 which can reduce assembly cost. The openings 21 in cover member 16 can be quickly and inexpensively formed using a punch process. The large clamping legs (suitably comprising each entire side wall of base member 17 ) provide a good clamping force and will function reliably over a long period.
[0061] Referring now to FIGS. 3 and 4 there are presented top plan and isometric exploded views of a fence 30 according to a further embodiment of the present invention. As may be seen in FIG. 3 , the post 32 that is used in this embodiment includes a cover 34 that has a cover member 18 and side members 19 as for the embodiment of FIG. 2 . However the post 32 has a wing 36 that extends laterally from one of the side walls 19 and which is used to fasten the post 32 to a support structure 38 by means of fastener 40 . The post 32 also includes internal wings 42 which are integrally formed on the interior of the sidewalls 19 and which assist the clamping legs 25 to clamp the 3rd member, in the form of slat 22 , therebetween.
[0062] FIGS. 5 and 6 respectively depict a further fence panel assembly 46 and a further post 44 that is used in that fence panel assembly, according to another embodiment of the present invention.
[0063] FIG. 7 is an end view of the post 44 of FIG. 6 . It can be seen from FIG. 7 that the post 44 comprises a base 48 that is snap fitted to cover member 50 by snap fit joints 52 a, . . . , 52 d.
[0064] The base 48 includes a base wall 54 from which first and second clamping legs 58 a, 58 b extend. It further includes first and second sidewalls 60 a, 60 b which extend from opposed sides of the base wall 54 with the first and second clamping legs 58 a, 58 b being located between the first and second sidewalls 60 a, 60 b.
[0065] It will be observed that remote ends of the first and second sidewalls 60 a, 60 b are snap fitted to opposed sides of the cover 50 by snap fit joints 52 a, 52 d.
[0066] The cover 50 includes an end wall 62 from which buttressing walls 64 a and 64 b project. The buttressing walls 64 a, 64 b and the clamping legs 58 a and 58 b are joined by snap fit joints 52 b and 52 c. The snap fit joints 52 b and 52 c are due to the clamping legs 58 a, 58 b being formed with outwardly disposed first grooves 66 a, 66 b, that receive corresponding inwardly projecting first lips 68 a, 68 b of the buttressing walls 64 a, 64 b.
[0067] The first and second clamping legs 58 a, 58 b terminate remotely in respective tapered heads 70 a, 70 b to assist in guiding a third member to be clamped there between in use. The third member, e.g a slat 22 , enters through an opening 72 (visible in FIG. 6 ) formed through the cover 50 . The first and second clamping legs 58 a and 58 b are also formed with second outwardly disposed grooves 74 a, 74 b that engage with corresponding inwardly projecting second lips 76 a, 76 b of the buttressing walls 64 a, 64 b during clamping of the third member.
[0068] As the third member, e.g. slat 22 , is inserted through opening 72 its end proceeds between tapered heads 70 a and 70 b thereby abutting the heads and causing the heads to swing outwardly until they are stopped by the abutment of the second lips 76 a and 76 b with the second grooves 74 a, 74 b. It will therefore be understood that the normal, unclamping, distance between the tapered heads is a little less than the width of the slat that is to be clamped therebetween.
[0069] FIGS. 8 and 9 show an exploded and assembled post 78 in use clamping a third member in the form of a post 22 . Post 78 is entirely similar to post 48 of FIG. 7 save that it is a little narrower.
[0070] FIG. 10 depicts a fence assembly 80 according to a further embodiment of the present invention. The fence assembly 80 makes use of a post 82 according to a further embodiment of the invention which is illustrated in cross section in FIG. 11 receiving an end of a 3rd member in the form of slat 22 . It will be observed that the base member 84 is formed with a base wall 88 from which sidewalls 86 extend both forwardly, portions 86 a, and rearwardly, portions 86 b. In this embodiment a second cover member 88 spans between the rearward portions 86 b of the sidewall 86 and is fitted thereto by snap-joints 90 . Fasteners such as screw 92 may be provided to secure for example a lockbox in the fence. In that case the second cover member 88 covers fastener 92 . A first cover member 94 with buttressing walls 96 is also provided. The buttressing walls 96 have lips 98 that engage the outside of tapered heads 100 of clamping legs 102 .
[0071] Referring now to FIG. 12 , there is illustrated a balustrade assembly 104 according to a further embodiment of the present invention. Balustrade assembly 104 makes use of a horizontally disposed post 106 according to a further embodiment of the present invention. The post 106 includes a base member 108 and a cover member 110 . It will be observed that first and second lateral wings 112 a, 112 b extend from distal ends of the first and second sidewalls 114 a, 114 b of base member 108 . Outer edges of the lateral wings are formed with snap fit formations 116 a, 116 b for receiving an edge of a balustrade 118 or other cover. The snap fit formations 116 a, 116 b include a slot 120 a, 120 b formed as an undercut adjacent tapering ridges 122 a, 122 b which assist in installing edges of the balustrade 118 into the slot. The base member 108 locates over the cover member 110 .
[0072] The base member 108 is formed with clamping legs 132 a, 132 b which extend from base wall 133 and which clamp a member 130 therebetween in use. Buttressing walls 128 a, 128 b extend from the interior of the end wall 126 of the cover member 110 past and adjacent to the clamping legs 132 a, 132 b. The buttressing walls 128 a, 128 b are formed with remote, inwardly projecting lips 134 a, 134 b which engage with corresponding grooves 136 a, 136 b formed along the outsides of the clamping legs. Accordingly, as the member 130 is inserted through an opening in cover member 110 it passes between the clamping legs 132 a and 132 b and pushes them outwardly so that the grooves 136 a, 136 b engage the lips 134 a and 1 34 b thereby assisting in fastening the base member 108 to the cover member 110 and firmly clamping the member 130 . The lateral wings 112 a, 112 b are fastened to a structure such as a railing assembly 138 , of which member 130 is a constituent by means of screws or other fasteners 140 a, 140 b, which extend through lateral wings 112 a, 112 b.
[0073] The above description identifies at least one specific, substantial and credible use for the invention. For example, preferred embodiments of the invention provide aluminum extrusion posts which are readily attached to each other and which are capable of clamping members such as fence slats.
[0074] In compliance with the statute, the invention has been described in language more or less specific to structural or methodical features. The term “comprises” and its variations, such as “comprising” and “comprised of” is used throughout in an inclusive sense and not to the exclusion of any additional features. It is to be understood that the invention is not limited to specific features shown or described since the means herein described comprises preferred forms of putting the invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims appropriately interpreted by those skilled in the art.
[0075] Throughout the specification and claims (if present), unless the context requires otherwise, the term “substantially” or “about” will be understood to not be limited to the value for the range qualified by the terms.
[0076] Any embodiment of the invention is meant to be illustrative only and is not meant to be limiting to the invention. Therefore, it should be appreciated that various other changes and modifications can be made to any embodiment described without departing from the spirit and scope of the invention.
[0077] Throughout the description and claims of this specification, the singular encompasses the plural unless the context otherwise requires. In particular, where the indefinite article is used, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise.
[0078] Features, integers, characteristics, compounds, chemical moieties or groups described in conjunction with a particular aspect, embodiment or example of the invention are to be understood to be applicable to any other aspect, embodiment or example described herein unless incompatible therewith.
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A post for a fit together panel comprising at least one said post and at least one slat, the post comprising a base member and a cover member, the cover member comprising a pair of sidewalls and an interconnecting end wall, the interconnecting end wall containing a plurality of openings through which the end of a slat can pass, the sidewalls adapted for extension over the channel member, the base member comprising a base wall and opposed sidewalls, at least one sidewall comprising a clamping leg adapted for clamping engagement against the end of a said slat passing through a said opening in the cover member, and snap fitting means on the channel member and/or the cover member to enable the channel member and the cover member to be snap fitted together.
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BACKGROUND
[0001] 1. Field
[0002] Embodiments relate to a bus bar holder.
[0003] 2. Description of the Related Art
[0004] Due to the increased use of gasoline vehicles, vehicle exhaust gases, which include various harmful substances e.g., nitrogen oxides, carbon monoxide due to incomplete combustion, hydrocarbon, etc., have created a very serious pollution problem. Furthermore, due to the steady depletion of fossil fuels, much research has been conducted on the development of next-generation energy sources and electric-powered vehicles. In this regard, traveling distances of an electric-powered vehicle depend on the performance of its battery. A battery may not be able to supply enough electric energy to guarantee that an electric-powered vehicle travels a sufficient distance. In the case of a vehicle that uses a fossil fuel, e.g., gasoline, light oil, or gas, the vehicle may be quickly resupplied with fuel at a gas station. However, in the case of an electric-powered vehicle, a significant amount of time may be required to recharge a battery, even if recharge stations are established. The time elapsed for charging a battery is a problem that has to be solved for commercialization of electric-powered vehicles. Therefore, improvement of battery performance is considered as the most important issue in relation to the development of electric-powered vehicles.
SUMMARY
[0005] Embodiments are directed to a bus bar holder, which represents advances over the related art.
[0006] It is a feature of an embodiment to provide a bus bar holder having improved connectivity with respect to electrodes of a battery having predetermined tolerances.
[0007] At least one of the above and other features and advantages may be realized by providing a bus bar holder for connecting electrode terminals of a plurality of batteries arranged in a lengthwise direction, the bus bar holder including a bus bar holder plate having an opening in a lengthwise direction thereof and configured such that at least some electrode terminals of the plurality of batteries are extendable through the opening and slidable along the opening; and a bus bar for electrically connecting at least two electrode terminals of adjacent batteries, wherein the bus bar holder plate includes a settling groove in which the bus bar is settled, and the bus bar attached to the electrode terminals is slidable when the electrode terminal slides along the opening.
[0008] The opening may be a single opening through which the electrode terminals are extendable through and slidable along the opening.
[0009] The opening may be configured to correspond to the electrode terminals, the opening having a predetermined length, for slidability of an electrode terminal, and the length of the opening being proportional to a distance from a reference point to the opening.
[0010] The opening may have a length proportional to a summed value of tolerances t of the batteries.
[0011] The settling groove may extend in the lengthwise direction of the bus bar holder plate and may correspond to the opening.
[0012] The bus bar holder plate may include an insulator, and the bus bar may include holes through which the electrode terminals extend.
[0013] At least one of the above and other features and advantages may also be realized by providing a bus bar holder for connecting electrode terminals of a plurality of batteries arranged in a lengthwise direction, the bus bar holder including bus bars for electrically connecting at least two electrode terminals of the plurality of batteries; a plurality of unit bus bar holders, the unit bus bar holders being between the bus bars and the batteries, having holes through which the electrode terminals are extendable to be attached to the bus bars, and having settling grooves in which the bus bars are settled; and a bus bar holder plate including an opening in which the plurality of unit bus bar holders are slidable in a lengthwise direction along sliding grooves, the sliding grooves being disposed in inner surfaces of the bus bar holder plate.
[0014] The opening of the bus bar holder plate may have a length sufficient for the plurality of unit bus bar holders to slide.
[0015] The bus bar holder may further include elastic members interposed between adjacent unit bus bar holders.
[0016] At least one of the above and other features and advantages may also be realized by providing a bus bar holder for connecting electrode terminals of a plurality of batteries arranged in a lengthwise direction, the bus bar holder including bus bars for electrically connecting at least two adjacent electrode terminals of the plurality of batteries; a plurality of unit bus bar holders, the unit bus bar holders being between the bus bars and the batteries, including holes through which the electrode terminals are extendable for attaching to the bus bars, and including settling grooves in which the bus bars are settled; and a length adjuster interposed between adjacent the unit bus bar holders.
[0017] The length adjuster may have an elastic bellows structure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The above and other features and advantages will become more apparent to those of ordinary skill in the art by describing in detail exemplary embodiments with reference to the attached drawings, in which:
[0019] FIG. 1 illustrates a perspective view of a bus bar holder attached to a battery module according to an embodiment;
[0020] FIG. 2 illustrates an exploded perspective view of the structure shown in FIG. 1 ;
[0021] FIG. 3 illustrates a sectional view taken along a line III-III′ of FIG. 2 ;
[0022] FIG. 4 illustrates an exploded perspective view of a bus bar holder attached to a battery module according to another embodiment;
[0023] FIG. 5 illustrates a sectional view taken along a line V-V′ of FIG. 4 ;
[0024] FIG. 6 illustrates an exploded perspective view showing a bus bar holder attached to a battery module according to yet another embodiment;
[0025] FIG. 7 illustrates a sectional view taken along a line VII-VII′ of FIG. 6 ;
[0026] FIG. 8 illustrates a sectional view taken along a line VIII-VIII′ of FIG. 6 ;
[0027] FIG. 9 illustrates a modification of the embodiment shown in FIG. 6 ;
[0028] FIG. 10 illustrates a plan view of FIG. 9 ;
[0029] FIG. 11 illustrates an exploded perspective view of a bus bar holder attached to a battery module according to still another embodiment; and
[0030] FIG. 12 illustrates a plan view of the bus bar holder shown in FIG. 11 .
DETAILED DESCRIPTION
[0031] Korean Patent Application No. 10-2009-0104311, filed on Oct. 30, 2009, in the Korean Intellectual Property Office, and entitled: “Bus bar Holder,” is incorporated by reference herein in its entirety.
[0032] Example embodiments will now be described more fully hereinafter with reference to the accompanying drawings; however, they may be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.
[0033] In the drawing figures, the dimensions of layers and regions may be exaggerated for clarity of illustration. It will also be understood that when a layer or element is referred to as being “on” another element, it can be directly on the other element, or intervening elements may also be present. In addition, it will also be understood that when an element is referred to as being “between” two elements, it can be the only element between the two elements, or one or more intervening elements may also be present. Like reference numerals refer to like elements throughout.
[0034] Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. In this regard, the present embodiments may have different forms and should not be construed as being limited to the descriptions set forth herein. Accordingly, the embodiments are merely described below, by referring to the figures, to explain aspects of the present description.
[0035] Referring to FIGS. 1 through 3 , a bus bar holder 101 according to an embodiment will be described below. FIG. 1 illustrates a perspective view of the bus bar holder 101 attached to a battery module 1 according to an embodiment. FIG. 2 illustrates an exploded perspective view of the structure shown in FIG. 1 . FIG. 3 illustrates a sectional view taken along a line III-III′ of FIG. 2 . The bus bar holder 101 may be interposed between bus bars 110 and the battery module 1 .
[0036] The battery module 1 may include a plurality of batteries 10 , a top plate 20 , a bottom plate 30 , side plates 40 , and end plates 50 . The batteries 10 may be various types of batteries, e.g., primary batteries or secondary batteries. For convenience of explanation, it is assumed below that the batteries 10 are secondary batteries, e.g., lithium secondary batteries. However, the batteries 10 may be other types of secondary batteries.
[0037] The secondary battery 10 may include an electrode assembly (not shown) and an electrode terminal 12 . The electrode assembly may include a negative electrode (not shown), a separator (not shown), and a positive electrode (not shown), and may have a wound structure or stacked structure. The electrode assembly may be housed in the secondary battery 10 and the electrode terminal 12 may be used for electrical connection to an external device. The secondary batteries 10 may be arranged next to each other in a predetermined direction and may be electrically connected to each other in parallel or in series. When connected in series, the secondary batteries 10 may be arranged so that the negative electrode of one secondary battery 10 contacts the positive electrode of an adjacent secondary battery 10 . The electrode terminals 12 of the secondary batteries 10 may be connected to each other via the bus bars 110 .
[0038] In the secondary battery 10 , the electrode assembly may expand or contract during charging and discharging. The expansion and contraction of the electrode assembly may act as a physical force on the secondary battery 10 . Thus, a sealing assembly accommodating the electrode assembly may physically expand or contract according to the physical deformations of the electrode assembly. Due to repeated expansions and contractions, the secondary battery 10 may be permanently deformed; and an increase in volume of the secondary battery 10 may increase the electrical resistance thereof. Thus, the efficiency of the secondary battery 10 may be deteriorated. Therefore, the end plates 50 may be arranged at both ends of the plurality of second batteries 10 ; and the side plates 40 may be connected to the side ends of the end plates 50 to firmly fix the plurality of secondary batteries 10 , to prevent the plurality of secondary batteries 10 from expanding/contracting in the lengthwise direction.
[0039] The top plate 20 may be disposed on top of the plurality of secondary batteries 10 and may be connected to the top ends of the end plates 50 . The bottom plate 30 may be disposed below the plurality of secondary batteries 10 to support the secondary batteries 10 and may be connected to the bottom end of the end plates 50 .
[0040] The bus bar 110 may electrically connect at least two electrode terminals 12 of neighboring batteries 10 . The bus bar 110 may contain a metal. Holes 110 a through which the electrode terminals 12 are to be inserted may be formed in the bus bar 110 ; and attaching units 120 may correspond to the holes 110 a . In other words, the electrode terminals 12 inserted through the holes 110 a in the bus bar 110 may be attached to the attaching units 120 . Thus, the bus bar 110 and the electrode terminals 12 may be attached to each other. The attaching units 120 may be screws or nuts attached to the electrode terminals 12 .
[0041] The bus bar holder 101 may be interposed between the bus bar 110 and the electrode terminals 12 . The bus bar holder 101 may include an insulation material to prevent a short circuit and may guide attachment of the bus bar 110 so that the bus bar 110 is easily attached to the electrode terminals 12 . When the bus bar holder 101 is attached to the electrode terminals 12 , if holes were to be disposed evenly apart from each other in the bus bar holder 101 , attachment problems may occur due to manufacturing tolerances of the secondary batteries 10 . When the secondary batteries 10 are manufactured, if the manufacturing tolerances are high, the manufacturing costs may increase. Furthermore, since the secondary batteries 10 are lithium secondary batteries and the volumes thereof may change during charging and discharging, if the bus bar holder 101 is attached to the electrode terminals 12 through holes disposed evenly apart from each other, a connection problem may occur between the bus bar holder 101 and the electrode terminals 12 when the secondary batteries 10 are charged or discharged.
[0042] The bus bar holder 101 of an embodiment may include a bus bar holder plate 100 . The bus bar holder plate 100 may include an opening 100 a formed in its lengthwise direction so that the electrode terminals 12 of the plurality of batteries 10 may be inserted through the opening 100 a . The electrode terminals 12 may slide, i.e., is slidable, along the opening 100 a . The opening 100 a may be a single opening through which all of the electrode terminals 12 may be inserted. The bus bar holder plate 100 may have a settling groove 100 b in which the bus bar 110 may be settled. The bus bar 110 attached to the electrode terminals 12 may slide in the settling groove when the bus bar 110 is fixed to the battery module 1 . The electrode terminals 12 may slide along the opening 100 a . A first bus bar 110 may be easily attached to the electrode terminals 12 regardless of the volumes of the secondary batteries 10 or manufacturing tolerance of the electrode terminals 12 . Furthermore, even if the volumes of the secondary batteries 10 change, other bus bars 110 attached to the electrode terminals 12 may slide along the settling groove 100 b . Thus, the bus bar holder 101 may have a structure easily adaptable to volume changes of the secondary batteries 10 .
[0043] Referring to FIGS. 4 and 5 , a bus bar holder 201 according to another embodiment will be described below. FIG. 4 illustrates an exploded perspective view of the bus bar holder 201 attached to the battery module 1 according to another embodiment. FIG. 5 illustrates a sectional view taken along a line V-V′ of FIG. 4 . According to the present embodiment, the bus bar holder 201 may include a bus bar holder plate 200 . Openings 200 a may be formed in the bus bar holder plate 200 in the lengthwise direction. First electrode terminals 12 of the plurality of secondary batteries 10 may be inserted through the openings 200 a , and the electrode terminals 12 may slide along the openings 200 a . The openings 200 a may be formed at locations corresponding to the electrode terminals 12 . Furthermore, the openings 200 a may have predetermined lengths so that the electrode terminals 12 may slide therein. In particular, the predetermined lengths may be proportional to a distance from a reference point S to the openings 200 a . The length of the openings 200 a may extend in correspondence to a sum of manufacturing tolerances t of the bus bar holder 201 as a distance A from the reference point S to the openings 200 a increases. The sum of the manufacturing tolerances t of the bus bar holder 201 indicates a value of a portion of the lengths of the openings 200 a of the bus bar holder plate 200 that extends in correspondence to the sum of manufacturing tolerances of the sizes of the secondary batteries 10 and the locations of the electrode terminals 12 . The sum of the manufacturing tolerances t may include dimensional tolerances or geometric tolerances of the secondary batteries 10 , the electrode terminals 12 , and the bus bar holder plate 200 . The manufacturing tolerances t may accumulate as the distance from the reference point S to the openings 200 a increases. Therefore, the openings 200 a may have lengths extending as much as sums of the diameter d and the accumulated manufacturing tolerances t, which is sufficient for inserting the electrode terminals 12 through the openings 200 a . Furthermore, the lengths of the openings 200 a may be determined in consideration of not only the manufacturing tolerances t, but also movements of the electrode terminals 12 due to contraction and/or expansion of the secondary batteries 10 . Distances between the secondary batteries 10 adjacent to each other may be fixed by the bus bars 110 . Thus, the length of openings 200 a corresponding to adjacent secondary batteries 10 may be equal. In other words, referring to FIG. 5 , the length of the opening 200 a , which is two distance units 2 A apart from a reference point, and the length of the opening 200 a , which is three distance units 3 A apart from the reference point, may be d+3t (d indicates the diameter sufficient for inserting the electrode terminals 12 through the openings 200 a , and 3t indicates the manufacturing tolerances t summed three times). The lengths of the opening 200 a , which is two distance units 2 A apart from the reference point, and the opening 200 a , which is three distance units 3 A apart from the reference point, may both be d+3t, since intervals among the electrode terminals 12 may be evenly maintained by the bus bar 110 , the bus bar 110 may move with respect to the greater value between d+2t, which is required at the point with respect to two distance units away from the reference point, and d+3t, which is required at the point with respect to three distance units away from the reference point.
[0044] Accordingly, the bus bar holder plate 200 with the openings 200 a , which may be formed in consideration of the manufacturing tolerances t, may be easily attached to the electrode terminals 12 of the battery module 1 . Furthermore, the bus bar holder 201 may be effectively adapted to compensate for contraction and expansion of the secondary batteries 10 .
[0045] Settling grooves 200 b may be formed in the bus bar holder plate 200 to correspond to the length of the openings 200 a . Therefore, when the electrode terminals 12 and the bus bars 110 are attached to each other and slide on the bus bar holder plate 200 , the electrode terminals 12 and the bus bars 110 may slide along the settling grooves 200 b.
[0046] Referring to FIGS. 6 through 8 , a bus bar holder 301 according to yet another embodiment will be described below. FIG. 6 illustrates an exploded perspective view of the bus bar holder 301 attached to the battery module 1 according to yet another embodiment. FIG. 7 illustrates a sectional view taken along a line VII-VII′ of FIG. 6 . FIG. 8 illustrates a sectional view taken along a line VIII-VIII′ of FIG. 6 .
[0047] According to the present embodiment, the bus bar holder 301 may include a bus bar holder plate 300 and a plurality of unit bus bar holders 310 .
[0048] The unit bus bar holder 310 may be interposed between the bus bar 110 and the secondary battery 10 . A holder hole 310 a may be formed in the unit bus bar holder 310 ; and the electrode terminal 12 may be inserted, i.e., may extend, through the holder hole 310 a so that the electrode terminals 12 and the bus bars 110 may be attached to each other. A settling groove 310 b for receiving the bus bar 110 may be formed in a surface of the unit bus bar holder 310 .
[0049] Sliding grooves 300 c may be formed in inner surfaces of the bus bar holder plate 300 so that the plurality of unit bus bar holders 310 may slide along the sliding grooves 300 c . Grooves 310 c corresponding to the sliding groove 300 c may be formed in the side surfaces of the bus bar holders 310 . Although the sliding grooves 300 c may be concave grooves and the corresponding grooves 310 c may be convex grooves, as illustrated in FIG. 8 , the embodiments are not limited thereto, and various modifications may be made. For example, the unit bus bar holders 310 may include casters, so that the unit bus bar holders 310 may slide on the inner surfaces of the bus bar holder plate 300 . Also, openings 300 a of the bus bar holder plate 300 may have sizes sufficient for the plurality of unit bus bar holders 310 to slide therein. Therefore, the bus bar holder 301 may be easily adapted to changes in locations of the electrode terminals 12 due to tolerances or deformation of secondary batteries 12 by sliding of the unit bus bar holders 310 . FIGS. 9 and 10 illustrate another modification of the embodiment shown in FIG. 6 . In particular, FIG. 9 illustrates a modification of the embodiment shown in FIG. 6 and FIG. 10 illustrates a plan view of FIG. 9 . According to the modified embodiment illustrated in FIGS. 9 and 10 , an elastic member 420 may be further disposed among a plurality of unit bus bar holders 410 . Accordingly, the unit bus bar holders 410 may elastically maintain intervals therebetween via the elastic members 420 .
[0050] Referring to FIGS. 11 and 12 , a bus bar holder 501 according to still another embodiment will be described below. FIG. 11 illustrates an exploded perspective view of the bus bar holder 501 attached to the battery module 1 according to still another embodiment. FIG. 12 illustrates a plan view of the bus bar holder 501 shown in FIG. 11 .
[0051] The bus bar holder 501 may include a plurality of unit bus bar holders 510 and length adjusters 520 .
[0052] The unit bus bar holder 510 may be interposed between the bus bar 110 and the secondary battery 10 . A holder hole 500 a may be formed in the unit bus bar holder 510 ; and the electrode terminal 12 may be inserted through holder hole 500 a so that the electrode terminals 12 and the bus bars 110 may be attached to each other. A settling groove 500 b for accommodating the bus bar 110 may be formed in a surface of the unit bus bar holder 510 .
[0053] The length adjuster 520 may elastically connect the unit bus bar holders 510 to the adjacent unit bus bar holder 510 . For example, as illustrated in FIGS. 11 and 12 , the length adjuster 520 may be an elastic object with a bellows structure. Accordingly, the bus bar holder 501 may be easily adapted to changes in length due to manufacturing tolerances as the length adjuster 520 elastically adjusts its length.
[0054] In comparison to the bus bar holder 501 illustrated in FIG. 11 , the bus bar holder 401 illustrated in FIG. 9 may restrict a sliding range of the electrode terminals 12 along the length of the bus bar holder plate 400 and may also be advantageous due to the bus bar holder plate 400 that guides the unit bus bar holders 410 during sliding.
[0055] The bus bar holders 101 , 201 , 301 , 401 , and 501 illustrated in FIGS. 1 through 12 may be applied to the battery module 1 . In an implementation, the battery module 1 may include twelve secondary batteries 10 ; and eight battery modules 1 may be stacked to form a battery pack. Such a battery module 1 or a battery pack may be applied to electric-powered vehicles, and it is clear that the bus bar holders 101 , 201 , 301 , 401 , and 501 may be applied to the battery module 1 and the battery pack.
[0056] Exemplary embodiments have been disclosed herein, and although specific terms are employed, they are used and are to be interpreted in a generic and descriptive sense only and not for purpose of limitation. Accordingly, it will be understood by those of ordinary skill in the art that various changes in form and details may be made without departing from the spirit and scope of the present invention as set forth in the following claims.
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A bus bar holder for connecting electrode terminals of a plurality of batteries arranged in a lengthwise direction, the bus bar holder including a bus bar holder plate having an opening in a lengthwise direction thereof and configured such that at least some electrode terminals of the plurality of batteries are extendable through the opening and slidable along the opening; and a bus bar for electrically connecting at least two electrode terminals of adjacent batteries, wherein the bus bar holder plate includes a settling groove in which the bus bar is settled, and the bus bar attached to the electrode terminals is slidable when the electrode terminal slides along the opening.
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This is a division of application Ser. No. 09/167,674, filed Oct. 7, 1998, and also claims the benefit of Provisional Application No. 60/061,238, filed Oct. 7, 1997.
The present invention relates to hydroforming, and more particularly to a method and apparatus used to make wrinkle-free hydroformed angled tubular parts.
The angled tubular parts herein contemplated are vehicle parts and more specifically parts of vehicle assemblies, such as vehicle frames and cradles. The part may be a frame member, a cross member, a side member, an A pillar part or the like.
Heretofore, angled parts of the type herein contemplated if made in tubular form with an angle greater than 30° required the welding of a reinforcing bracket to the convex portion of the bend in order to strengthen the reduced thickness of the wall at the convex portion of the bend. The welding of the reinforcing bracket to the tubular bent part having a reduced thickness at the convex portion sufficient to require the reinforcing bracket added material cost and unwanted weight to the finished part. There is always a need to make vehicle parts lighter and in a more cost effective manner by improved manufacturing methods and apparatus.
BRIEF DESCRIPTION OF THE INVENTION
An object of the present invention is to fulfill the need expressed above. In accordance with the principles of the present invention, this objective is obtained by providing a method of hydroforming an angled tubular part comprising disposing an angled metal tubular blank within a generally correspondingly angled die cavity. The tubular blank having an exterior surface wherein at an angled portion of the tubular blank the exterior surface has a concave surface portion and a convex surface portion on generally opposite sides of the tubular blank. The opposite ends of the tubular blank are sealed, providing high pressure fluid to an interior of the tubular blank, expanding the blank into conformity with surfaces defining the die cavity as a result thereof. Applying force to at least one end of the tubular blank so as to create longitudinal flow of metal material within the tubular blank to maintain a wall thickness of the blank within a predetermined range, wherein a greater amount of force is applied to a portion of the tubular blank which is longitudinally aligned with the convex surface portion of the tubular blank in comparison with the amount of force applied for a portion of the tubular blank so as to create a greater amount of flow of metal material toward portions of the tubular blank adjacent the convex surface portion in comparison with portions of the tubular blank adjacent the concave surface portion, so as to inhibit wrinkle formation at the portions of the tubular blank adjacent the concave portion.
In accordance with the principles of the present invention, the above recited object is also obtained by providing a hydroforming die assembly for forming an angled tubular part comprising a die structure having die parts, which include die surfaces cooperable to define an angled die cavity into which a bent tubular metal blank is to be placed. The bent tubular metal blank has an exterior surface which includes a concave surface portion and a convex surface portion on opposite sides thereof. The first and second ram assemblies have respective first and second associated tube-end engaging structures disposed at opposite ends of the die cavity. The tube-end engaging surfaces are constructed and arranged to be inserted into the opposite ends of the die cavity. The tube-end engaging structures have tube-end engaging surfaces for engaging opposite ends of the tubular metal blank placed in the die cavity. The tube-end engaging structures further comprise ports constructed and arranged to provide hydroforming fluid to an interior of the tubular metal blank. The ram assemblies further comprise a fluid pressurizing system constructed and arranged to increase pressure of the hydroforming fluid provided to the interior of the tubular metal blank sufficient to expand the tubular metal blank into conformity with the die surfaces defining the die cavity. At least one of the tube-engaging structures being movable by the associated ram assembly into forced engagement with one end of the opposite ends of the tubular metal blank so as to longitudinally compress the tubular metal blank between the tube-end engaging structures and thereby create longitudinal flow of metal material during expansion of the tubular metal blank in order to maintain a wall thickness of the tubular metal blank with a desired range. At least one movable tube-end engaging structure has the tube-end engaging surface thereof constructed and arranged to apply a greater amount of force to a portion of one end of the tubular metal blank which is longitudinally aligned with the convex surface portion of the tubular metal blank in comparison with an amount of force applied to a portion of one end of the tubular metal blank which is longitudinally aligned with the convex surface portion of the blank so as to create a greater amount of longitudinal flow of metal towards the convex surface portion of the tubular metal blank in comparison with the amount of longitudinal flow of metal towards the concave surface portion of the tubular metal.
In accordance with the principles of the present invention, the above recited object is also obtained by providing a vehicle part suitable to form a part of a rigid vehicle assembly, such as a vehicle frame assembly or the like. The vehicle part is formed from a cylindrical blank having a predetermined wall thickness and a predetermined peripheral dimension. The cylindrical blank is bent and hydroformed to provide a tubular wall having a central bend therein of at least approximately 30° and opposite angularly related end portions. The central bend has a peripheral dimension in excess of approximately 10% of the predetermined peripheral dimension of the cylindrical blank. The central bend includes a concave portion free of wrinkles and a convex portion having a wall thickness within plus of minus 10% of the predetermined wall thickness of the cylindrical blank.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of a hydroforming system, partly in section, and showing a bent tube blank disposed in a lower die structure in accordance with the principles of the present invention;
FIG. 2 is a perspective view of a tube-engaging portion of a hydraulic ram in accordance with the present invention;
FIG. 3 is a view similar to that shown in FIG. 1, but showing the hydraulic system rams sealingly inserted into the opposite ends of the tube blank;
FIG. 4 is an enlarged sectional view of the interface between one end of the tubular blank and the associated hydraulic ram;
FIG. 5 is a view similar to that in FIG. 3, but showing the bent tube being filled with water in preparation for the next hydroforming step;
FIG. 6 is a view similar to FIG. 5, but showing the next step in the hydroforming process in which pressurized water expands the tube into its final shape in accordance with the present invention;
FIG. 7 shows hydroforming system, partly in section, in accordance with a second embodiment of the present invention;
FIG. 8 is a perspective view showing the notched end of a tube blank in accordance with the second embodiment of the present invention;
FIG. 9 is an enlarged sectional view showing the interface between one end of the tubular blank and the associated hydraulic ram in accordance with the second embodiment of the present invention.
FIG. 10 is a cross-sectional view of a vehicle part manufactured in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring more particularly to FIG. 1, there is shown a hydroforming system 10, that includes a hydroforming die structure 12, and a pair of hydraulic ram assemblies 16 and 18. The die structure 12 includes a lower die portion 14, a cross section, as shown in FIG. 10, and of which is depicted schematically in FIG. 1. The die structure 12 is manufactured substantially in accordance with application Ser. No. 60/024,524, filed Aug. 26, 1996, which is hereby incorporated by reference, with the exception of the shape of the die cavity formed thereby.
The hydraulic ram assemblies 16 and 18 are disposed at opposite ends of the die structure 12. The ram assemblies 16 and 18 generally include respective ram housings 20 and 22, and respective outer rams 24 and 26, which project outwardly from the ram housings 20 and 22.
As can be seen in FIG. 3, the outer ram 24 is movable outwardly from the ram housing 20 and into engagement in sealing relation with one end 28 of a tube blank 70 to be hydroformed, which has been placed in the lower die portion 14. Similarly, the outer ram 26, is movable outwardly from the ram housing 22 and is constructed and arranged so as to engage and seal the opposite end 28 of tube 70 (see FIG. 4). The ram assemblies 16 and 18 are provided with fluid pressurizing intensifiers and are hydraulically operable to longitudinally compress a tubular blank during expansion of the tubular blank in accordance with conventional hydroforming systems. It is alternately contemplated that the ram assemblies 16 and 18 may operate in accordance with the teachings of application Ser. No. 60/043,950, filed Apr. 16, 1997, and hereby incorporated by reference. In accordance with the teachings of Ser. No. 60/043,950, the hydroforming system 10 would include a valve arrangement that is used to control fluid flow into the outer ram 24 when the rams 24 and 26 are engaged and sealed with the tube ends 28. The outer ram 24, in turn, directs fluid, preferably water, into the interior of the tube 70.
The outer rams 24 and 26 each comprise a main portion 46, and an end cap 48 fixed to the main portion. More particularly, each main portion 46 is in the form of a robust tubular sleeve portion, extending outwardly from a respective ram housing 20 or 22. Each end cap 48 includes an annular flange portion 52 bolted and sealed by appropriate fasteners 54 to the circular edge at the distal end of the main portion 46. Each end cap 48 further includes an elongated tubular portion 56 integrally formed with the flange portion 52 and extending axially in an outward direction with respect to main portion 46. Each tubular portion 56 is of reduced exterior diameter in comparison with flange portion 52 and has a generally cylindrical exterior surface, which is constructed and arranged to form a peripheral seal with the corresponding cylindrical surface 62 formed at each end of the hydroforming die cavity when the upper and lower die are in a closed position (i.e., when the upper die portion is lowered onto lower die portion 14).
As best seen in FIG. 2, the end cap 48 terminates in a nozzle portion 64, which is integrally formed with and projects outwardly from the tubular portion 56. The nozzle portion 64 is substantially tubular in shape, and is of a reduced outer diameter in comparison with the tubular portion 56. A radially extending annular flange surface 66 is disposed at the transition between the tubular portion 56 and the nozzle portion 64. The flange surface 66 has a partial annular portion 67 constituting a tube engaging surface portion constructed and arranged to engage, in sealing relation, an end 28 of the tube 70 during a hydroforming operation. The flange surface 66 further includes a notched or cut-away surface portion 78 which extends away from the end 28 of the tube when the surface portion 67 is engaged. The partial annular surface portion 67 transitions into the cut-away or notched portion 78 at corners 79.
Each nozzle portion 64 has a cylindrical exterior surface constructed and arranged to be frictionally received within one end of the tube 70 and slidably engage interior cylindrical surface portions at the ends of the tube 70 so that the ends of the tube are sealed during high pressure hydroforming. A longitudinal bore 69, extends through each end cap 48, and is constructed and arranged to communicate high pressure fluid from the outer rams 24 (or at least one of the outer rams), to the inner confines of tube 70.
When the upper die structure is lowered onto the lower die structure 14, an expansion die cavity 72 is formed and is defined by peripheral die cavity surfaces corresponding to the desired final formed shape of the hydroformed tube 70. For most applications, the tube blank 70 will have a circular cross-section and will be hydroformed to have a rectangular cross-section as described in application Ser. No. 60/024,524. Thus, it can be appreciated that the die cavity 72 transitions from a cylindrical configuration at opposite ends thereof (e.g., at surfaces 62) to a squared configuration cross-section wise at a central portion thereof. It can be seen in FIG. 1 that in this hydroforming application, the desired hydroformed part has somewhat of a bent configuration. In particular, the present invention achieves its greatest benefit when hydroforming parts which are to be provided with a bend of 30° or greater when comparing central longitudinal axes at opposite ends of the tube. For example, in FIG. 1, angle α is greater than 30°. As can be appreciated from FIG. 1, angle α represents not only the angle of deviation or bend of the tube in comparison with a straight tube, it also represents such angling of the die cavity into which the tube is placed. Also in accordance with the invention, the tubular blank 70 which is to be hydroformed, and which is originally manufactured as a straight tube in a standard roll-forming operation, is pre-bent to fit within the arcuate contours of the die cavity 72. This pre-bending operation can be accomplished, for example in a conventional computer numeric controlled ("CNC") assembly.
Also, in accordance with the present invention, the hydroformed part is to be expanded at some portions by preferably at least 10% in comparison with the original diameter of the tubular blank, and more preferably at some portions by at least 20%. In order to accomplish this without undesirably thinning the walls of the hydroformed part, the opposite ends 28 the tube 70 are longitudinally compressed by inward movement of rams 24 and 26 towards one another. This longitudinal compression of the tube 70 during expansion thereof creates longitudinal flow of the metal material forming the tube 70 so that the wall thickness of the hydroformed part remains within about 10% of that of the original blank. It can be appreciated that unless certain measures are taken, an accumulation of flowed metal may occur at the concave portion 75 of the bend (when viewing the exterior surface of the tube), because less material flow is required here in comparison with the convex portion 76 of the bend.
In order to provide for a wrinkle free part relative to the exterior configuration of concave portion 75, the notched portion 78 formed in the annular flange surface 66 of outer rams 24 and 26 is provided. More particularly, referring now to FIGS. 3 and 4, it can be seen that the partial circular portions 67 of annular flange surfaces 66 of outer rams 24 and 26, engage the ends 28 of tube 70. As indicated in the drawings, notched portions 78, are longitudinally aligned with the inner concave portion 75 of tube 70. Because the notched portions 78 angle away from the adjacent portions of tube ends 28 and are not forced against the tube ends 28 when rams 24 and 26 are forced relatively towards one another, less metal flows to the inner concave portion 75 in comparison to convex portion 76 so that wrinkles are not formed at concave portion 75.
Referring back to FIG. 1, it can be seen that the end portions of tube 70 are optionally provided with an indent 80, providing a further restriction to metal material flow at positions towards the end of the tube which are also longitudinally aligned with the concave inner portion 75 of the tube 70. The indents 80 are provided sufficiently close to the ends 28 so as to constitute a portion of the ends of the tube which are cut off after a hydroforming operation. These cut-off end portions are not expanded to any significant extent and remain with a substantially circular cross-section even after the hydroforming operation.
As shown in FIG. 5, the hydroforming process is commenced by placing tube 70 in the lower die structure 14, and then sealing the ends of the tube 70 with outer ram assemblies 24 and 26. The tube 70 is then filled with hydraulic fluid. Particularly, water and oil based additives are directed through part 42, into the outer ram 24, where it is then directed through the bore 69 into tube 70. The fluid is subsequently communicated through bore 69, in the opposite outer ram 26, where it is then directed to a lower tank, by means of part 44. During this process, the tube 70 is vented and purged of substantially all air bubbles and completely filled interiorly with hydraulic fluid, as indicated by reference letter F. After the tube is filled with fluid, the upper die portion is lowered onto lower die portion 14 to form the closed die cavity 72.
As can be seen in FIG. 6, the hydraulic fluid F is pressurized with intensifiers within the hydraulic ram assemblies 16 and 18 to begin tube expansion. Concurrently with radial expansion of the tube 70, outer rams 24 and 26 are forced inwardly toward one another against the opposite ends 28 of tube 70. As the annular flange surfaces 66 force the tube ends 28 inwardly, the metal material forming the tube 70 flows longitudinally along the length of the tube, so that the diameter of the tube can expand the tube in the bent areas by 10% or greater, while the wall thickness of the hydroformed tube 70 is maintained preferably within plus or minus 10% of the wall thickness of the original tube blank.
It can be appreciated that because the notched portions 78 of annular flange surfaces 66 do not forcibly contact the tube ends, substantially less metal is flowed along the portion of the tube longitudinally aligned with the concave inner portion 75. While some contact between the notched portions 78 and tube ends 28 is possible as a result of material flow and/or tube deformation, and would actually enhance the seal of the associated ram with the tube end, such contact would occur with much less force and at a later time than that which occurs at annular surface portion 67. Additionally, the indented portions 80 of the tube blank are also longitudinally aligned with the concave portion 75 of the tube and provide an area at which metal that attempts to flow longitudinally toward the concave portion 75 of the bent tube 70 is restricted, so as to reduce flow of metal towards concave portion 75. As a result, wrinkles are not formed at the concave portion 75.
Preferably, in accordance with the invention, the tube engaging annular surface portion 67 of the flange surface 66 comprises between 80°-160° (or about 22%-44%) of a complete circle. The extent of engagement with the ends of the tube 28 is a function of the angle α, the radius at concave portion 75, and the diameter of the tube 70. The greater the angle α and tighter the radius of the bend, the lesser the extent of tube engaging annular surface portion 67 is provided. In addition, for greater diameter tubes, the greater the extent of engagement is required and thus a larger engaging annular surface portion 67 is provided.
Most preferably, fluid pressure between 2,000 and 3,500 atmospheres is used to expand the tube. Depending upon the application, it may also be preferable to utilize pressures between 2,000 and 10,000 atmospheres, although even higher pressures can be used.
After tube 70 is formed into the desired wrinkle-free shape, generally corresponding to the shape of die cavity 72, hydraulic pressure is released, the outer rams 26 and 28 are driven outwardly from the tube ends 28, and the upper die structure is raised.
The notched portion 78 is shown on both annular flange surfaces 66 of the outer rams 24 and 26. It is contemplated by the present invention, however, that the notched portion 78 could be provided on only one of the outer rams. This is particularly the case where only one end of the tube 70 is to be pushed inwardly. In that event, the notched portion 78 is likely to be provided only on the one ram being pushed, and not the opposite stationary ram. Pushing one end of the tube is a desirable approach to hydroforming where one end portion of the tube is to be expanded to a significantly greater extent than the opposite end portion. The end portion to be expanded is the one to be pushed.
It is also contemplated that indents 80 could be omitted, or that only a single indent 80 can be provided. Normally, indent 80 would be used only in conjunction with an adjacent notched ram which is to be pushed inwards.
Shown in FIGS. 7, 8 and 9, is a second embodiment of the present invention. In this embodiment, the tube ends 128 are cut back or notched as shown at 182. The cut portions 182 are longitudinally aligned with the concave portion 175 of tube 170. Also, in this embodiment, the annular flange surfaces 166 of the rams are not provided with a notched portion. Rather, a complete, annular flange surface 166 is provided. The annular flange surfaces 166 of outer rams 124 and 126 in this embodiment push longitudinally inward against the end portions 128 of the tube 170. Since the annular flange surfaces 166 do not engage or push inwardly against the tube at cutoff portions 182, substantially less metal is flowed along the portion of the tube longitudinally aligned with the concave inner portion 175. It can be appreciated that with this second embodiment of the present invention, indents 180 may also be included to restrict metal flow within the tube and aid in the wrinkle-free hydroforming process. As shown, the indents 180 are spaced only slightly inward from tube ends 128, at a position which is eventually cutoff from the resulting hydroformed product.
Similarly to the first embodiment, a cut portion 182 could be provided at only one end of the tube 170 to be pushed inwardly.
While the invention has been disclosed and described herein with reference to the preferred embodiment, it will be apparent that variations and modifications may be made therein without departure from the spirit and scope of the invention. Therefore, the following claims are intended to cover all such modifications, variations, and equivalents in accordance with the principles and advantages noted herein.
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A vehicle part suitable to form a part of a rigid vehicle assembly, such as a vehicle frame assembly or the like. The vehicle part is formed from a cylindrical blank having a predetermined wall thickness and a predetermined peripheral dimension. The cylindrical blank is bent and hydroformed to provide a tubular wall having a central bend therein of at least approximately 30° and opposite angularly related end portions. The central bend has a peripheral dimension in excess of approximately 10% of the predetermined peripheral dimension of the cylindrical blank. The central bend includes a concave portion free of wrinkles and a convex portion having a wall thickness within plus or minus 10% of the predetermined wall thickness of the cylindrical blank.
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BACKGROUND OF THE INVENTION
The present invention relates to swimming apparatus. More particularly, the invention relates to flipper type apparatus suitable for wearing on a swimmer's feet. The apparatus of the invention optimizes a swimmer's propulsion resulting from a given movement.
Numerous aquatic swimming aid devices have been proposed in the prior art. Several of these devices relate to foot or leg fitting flippers while others disclose upper torso suits and glove-type swimming appliances.
U.S. Pat. Nos. 3,934,290, 3,344,449 and 1,530,560 relate to lower body apparatus fitting over the legs of a swimmer in a mermaid-type arrangement. These patents include reference to detachable flukes and boot portions having both separable and unitary foot and leg portions.
Thus, U.S. Pat. No. 3,934,290, Le Vasseur, discloses a swimming system having a single fin for the feet with a large fluke and two foot openings leading to foot pockets separated by a cushion. A series of water directed openings extend rearward and outward from a line above the toe portions of the pockets diagonally through the fluke to a line near a tip of the fluke on a rearward portion of the fin. A fastening surrounds the fin near instep areas of the foot-receiving pockets. A leg sheath has a corresponding lower fastening, a cushioning divider between legs and an achilles cushion above a heel portion. A reinforced upper waist band fastens to a jacket portion with hand openings which overlie hand fins formed of flat circular plates with finger and palm cutouts mounted between two pieces of synthetic dolphin skin. The helmet with an annular neck encircling cushion completes the entire body covering with a synthetic dolphin skin exterior.
The foot fluke portion of Le Vasseur has a broad, laterally extended fluke, with a distal edge. Holes let water out of foot pockets in the foot-receiving portion. Port openings connect diagonal passageways with lower rearward ports. The foot fluke fin has a laterally extended fluke portion, which tapers outwardly and terminates in a curved distal edge. Foot-receiving pockets are divided centrally by a cushion. Openings provide access to the foot-receiving pockets in the foot mounting portion. Holes permit flow out of toe areas of pockets when feet are inserted in the pockets. A parallel row of plural port openings leads from an area of the fluke just forward of the toe through diagonal channels to rearward ports.
U.S. Pat. No. 3,344,449, Grilli, discloses a swimsuit in the form of a sock or bag of elasticized fabric or cloth having a tubular body tapering from one end to the other. The narrow end of the body of the swimsuit is closed forming a pocket or foot portion for the feet of the wearer. The pocket is formed with spaced perforations at opposite sides. A fin structure is attached to the pocket. The fin structure comprises a triangular-shaped body formed of two sheets to solid rubber, the sheets at the wide portion of the body being juxtaposed and secured together by adhesive and at the upper narrower portion being spaced apart providing a socket portion to receive the foot portion. The upper tapered portion is formed with spaced perforations aligned with the perforations in the foot portion, so that passages are provided across the socket portion of the fin structure. The wide portion of the body is curved at its bottom edge and indented centrally and is formed with curved laterally extending wing portions.
Hip mounted fins are described in U.S. Pat. No. 3,428,980, wherein the fins are designed to work against the feet in dolphin kicks.
U.S. Pat. Nos. 3,934,290, 2,313,979 and 1,049,488 disclose glove-type swimming appliances.
French patent No. 2,149,103, Frieri et al, discloses a rubber shoe shaped as a fin or flipper and reinforced with a high elasticity element of polyester resin reinforced with glass fibers.
U.S. Pat. No. 3,411,165, Murdoch, discloses a swim fin having a relatively thin, transversely bowed, nonstretched, bellied web which reversibly cups during swimming due to marginal portions flexibly secured to the front of a shoe-like member and to the inner portions of diverging inflexible forward extending ribs.
U.S. Pat. No. 3,529,565, Iglesias, discloses a dynafin accessory for use by scuba divers having a transmission bar adaptable for being positioned adjacent a front side of a swimmer. One end of the transmission bar is secured to a shoulder support and an opposite end of the transmission bar is secured to a fin assembly. The shoulder support is mountable over the swimmer's shoulders. The fin assembly is operated by said swimmer's feet.
None of the aforementioned patents discloses any of the load-bearing, resilient frame member of substantially arcuate configuration having two relatively stiff spaced ends and a common connecting portion, the frame member being sufficiently flexible to permit bending and twisting in response to an applied load, the substantially flexible, resilient webbing juxtaposed between the end legs and secured thereto, the webbing bowing in response to an applied load, or the foot-receiving pocket in the common connecting portion of the frame member for accommodating both feet of the swimmer of the apparatus of the invention, whereby in operation the apparatus captures a pocket of water in the flexible webbing thereby distorting the shape of the frame member and the webbing and propelling the water rearward in a narrow stream as the swimmer effects upward and downward foot motion.
Although some of the aforementioned references teach the use of a porpoise tail shaped flipper as as aid to aquatic propulsion, none of these patents discloses a flipper internal construction of the type of the invention, which provides maximum propulsive benefit. Since any given shape may be constructed to be rigid or flexible, those skilled in the art have heretofore been left unaided in designing flipper-type apparatus which provides strength and flexibility in the proper regions in order to maximize the propulsion advantages achievable through their use.
The principal object of the invention is to provide swimming apparatus which greatly increases a swimmer's propulsive thrust through the water.
An object of the invention is to provide swimming apparatus of simple structure, which is used with facility and considerably increases a swimmer's speed through the water.
Another object of the invention is to provide swimming apparatus having a selectively flexible flipper tail portion to permit bowing or arching of the webbing in both the upward and downward directions thereby greatly increasing the forward thrust of a swimmer.
Still another object of the invention is to provide swimming apparatus having a construction which permits a pumping motion by a swimmer to create an efficient water jet rearward thereby increasing the swimmer's speed.
Yet another object of the invention is to provide swimming apparatus of flipper type which is sufficiently resilient to trap water within its tail portion, and with the proper hydrofoil, propel the water efficiently to the rear thereby greatly increasing the forward thrust of a swimmer through the water.
BRIEF SUMMARY OF THE INVENTION
In accordance with the invention, swimming apparatus for increasing the propulsion of a swimmer comprises a load-bearing, resilient frame member of substantially arcuate configuration having two relatively stiff spaced ends and a common connecting portion. The frame member is sufficiently flexible to permit bending and twisting in response to an applied load. Substantially flexible, resilient webbing is juxtaposed between the ends and secured thereto, and bows or arches in response to an applied load. A foot-receiving pocket in the common connecting portion of the frame member accommodates both feet of the swimmer, whereby in operation the apparatus captures a pocket of water in said flexible webbing thereby distorting the shape of the frame member and the webbing and propelling the water rearward in a narrow stream as the swimmer effects upward and downward foot motion.
The frame member has a leading edge and the foot-receiving pocket is positioned well into the leading edge.
The webbing overlays the surface of the frame member to form a continuous coating along the surface of the apparatus.
The frame member consists of material of sufficiently compliant properties to permit bending and twisting of the ends as water is captured in the webbing.
The ends of the frame member bend upward and toward each other and each of the ends twists essentially about its axis.
The frame member has a cross-sectional hydrofoil configuration for providing lift in both kicking directions and for accelerating the flow of water into a pocket formed by bowing action of the webbing in motion.
The frame member has a spanwise hydrodynamic configuration for enhancing the entrapment of water and facilitating the flow of water into a pocket formed by bowing action of the webbing in motion and into a concentrated jet stream.
The frame member and the webbing consist of material sufficiently resilient to hurl water captured in the webbing rearward to impart a pulse of propulsive force to the swimmer.
The frame member is composed of aluminum, spring steel, or the like.
The webbing may consist of a plastic material or rubber.
In accordance with the invention, swimming apparatus for increasing the propulsive thrust of a swimmer comprises a generally Y-shaped frame member of high strength, ductile material having a high resiliency. The frame member has a pair of forked portions spaced from each other at their free ends. Fluked webbing is connected between the forked portions of the frame member. The webbing consists of flexible plastic material which permits bowing between the forked portions when the webbing encounters fluid resistance. A foot-receiving pocket in the frame member at the juncture of the forked portions accommodates both feet of the swimmer.
The foot-receiving pocket is encompassed within a housing integrally formed as a portion of the frame member.
The housing has a smooth and fluid construction for minimizing hydrofoil drag.
In accordance with the invention, swimming apparatus for increasing the propulsive thrust of a swimmer comprises a plastic member formed in the general shape of a porpoise tail having a tail root, a leading edge portion on both sides of the tail root, the leading edge portion having a hydrofoil cross-section, a webbing portion extending between the tail root and leading edge portion, the tail root and leading edge portion consisting of material stiffer than the webbing portion and the webbing portion consisting of material more flexible than that of the tail root and leading edge portion for permitting bowing of the webbing portion and deformation of the leading edge portion as fluid resistance is encountered, and means in the tail root for accommodating both feet of the swimmer. The webbing and leading edge portions are sufficiently resilient to return to their original shape during pumping motion of the feet of the swimmer thereby imparting a rearward velocity to fluid captured in the webbing and a forward thrust to the swimmer.
BRIEF DESCRIPTION OF THE DRAWINGS
In order that the invention may be readily carried into effect, it will now be described with reference to the accompanying drawings, wherein:
FIG. 1 is a bottom elevational view of an embodiment of the swimming apparatus of the invention;
FIG. 2 is a side view of the embodiment of FIG. 1 in a horizontal plane;
FIG. 3 is a schematic diagram showing the arching of the webbing material and the twisting of the frame member, as viewed from the rear;
FIG. 4 is a top view of an embodiment of the basic frame member of the swimming apparatus of the invention;
FIGS. 5, 6 and 7 are top elevational views of various other embodiments of the swimming apparatus of the invention, illustrating different fluke and webbing constructions;
FIG. 8 is a top elevational view, on an enlarged scale, of another embodiment of the swimming apparatus of the invention;
FIG. 9A is a cross-sectional view, taken along the lines IXA--IXA, of FIG. 8;
FIG. 9B is a cross-sectional view, taken along the lines IXB'IXB, of FIG. 8;
FIG. 9C is a cross-sectional view, taken along the lines IXC--IXC, of FIG. 8; and
FIGS. 1OA and 10B are perspective views illustrating the swimming apparatus of the invention in use, FIG. 1OA showing the swimmer before the kick and FIG. 1OB showing the swimmer after the kick.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 shows an embodiment of the swimming apparatus of the invention fitted on the feet of a swimmer. The swimming apparatus of the invention comprises a flipper 11 formed in the general shape of a porpoise tail and adapted to accommodate both feet 13 of the swimmer or user snugly within a foot-receiving pocket 14 to permit movement of the flipper 11 in water with good leverage and without said flipper slipping off said feet. Fastening means such as straps 20 and 22 (FIGS. 10A and 10B) may also be utilized to insure that the user's feet remain securely within the pocket 14 as said user pumps his legs. The foot-receiving pocket 14 is positioned well into the leading edge of the flipper 11.
The swimming apparatus or flipper assembly of the invention includes a generally Y-shaped frame, support, or horn member 15 (FIGS. 1, 3 and 4) which is generally constructed in an arcuate or wishbone fashion. The frame member 15 provides the basic structural integrity for the flipper. The frame member 15 has a carefully selected hydrofoil cross-section, as shown in FIGS. 9A, 9B and 9C.
Webbing 17 (FIG. 1) covers the frame member 15 and is shaped to form the desired fluke pattern at the trailing edge of said webbing between the frame, support, or horn ends 12 (FIG. 4). The thickness of the webbing 17 is selected to permit sufficient flexibility to effect bowing, arching, ballooning, or cupping of said webbing as the flipper 11 is moved through the water. As the user's legs are pumped upward or downward, the webbing material 17 within a flipper fan section 19 encounters sufficient water resistance to force a bowing, arching, ballooning or cupping of the fan between the ends 12 of the more rigid frame member 15. With the continuation of the pumping movement, the fan section 19 returns to its normal position and, in fact, will overshoot its normal position to arch, bow, or cup in the opposite direction.
The frame, support, or horn member 15, shown most clearly in FIG. 4, has two forked leg portions or ends 12 and a common or root portion 16. Structurally, the frame member 15 is sufficiently resilient to permit a complex bending and twisting of said frame member as the fan portion 19 of the webbing 17 encounters fluid resistance. More particularly, the ends 12 of the frame member 15 bend upward and toward each other and each of said ends twists essentially about its axis. The resiliency of the frame member 15 serves to return said frame member to its normal position as the pumping stroke is continued by the swimmer.
Plastic materials such as blends RP-6414, RP-6405 or Thane (trademark) produced by Smooth-on Corporation are suitable as the webbing material 17. These plastics are preferably injection molded into the desired shape. The frame member 15 may be formed of resilient metallic sheet or tubing material such as, for example, aluminum or spring steel. Holes may be drilled into the frame member 15 to form a better anchor with the plastic material injected about said frame member.
In an alternative embodiment, the need for a separate frame member may be eliminated and the swimming apparatus may be an integral plastic structure. Such structure may assume the aforedescribed shape of the separable frame member 15. Plastic materials such as those hereinbefore described may be injected into a mold to form thicker hydrofoil portions along the leading edge with thinner, more flexible, regions in the webbing area. As one skilled in the art will recognize, there are a variety of techniques and materials which will produce an integral plastic article having varying degrees of flexibility in selected regions.
Cupping, arching or bowing action of the webbing 17 creates a slingshot action of the frame or support member 15 and said webbing which increases the velocity of the water forced to the rear by the flipper action. The forward propulsive thrust or velocity of the swimmer 24 (FIGS. 10A and 10B) is thereby increased, improving his or her overall swimming efficiency.
The hydrofoil cross-section of the frame member 15 essentially has the shape of a polywog, as shown in FIGS. 9A, 9B and 9C and functions to accelerate the flow of water into a pocket 26 (FIGS. 10A and 10B), helps to trap more water and to concentrate it in a narrow stream or jet and helps approach the optimum performance of a dolphin's fluke. The hydrofoil cross-sectional configuration also increases the lift in the direction of pumping motion of the swimmer 24 thereby easing such motion, as shown in FIGS. 1OA and 1OB.
The creation of the improved thrust constitutes the fundamental novelty of the invention. The flipper assembly of the invention, having a stiff leading edge portion 15 and a flexible webbing fan section 19 capable of cupping, bowing or arching when moved in the normal manner, increases the discharged water velocity, resulting in improved forward thrust of the swimmer.
FIG. 2 is a side view of the embodiment of FIG. 1. As shown in solid lines 21 in FIG. 2, the construction of the flipper 11 may be contoured to closely match the profile of the user's feet. Alternatively, the profile of the flipper 11 may be less contoured effecting a more forward center of gravity. Molding and finishing requirements are important and play a dominant role in the precise construction selected. Design parameters may vary about the basic requirements for a resilient and flexible fan section 19 which may be cupped, arched, or bowed within a relatively rigid frame member 15.
The broken line 23 in FIG. 2 illustrates a change in the profile of the flipper 11 as a downward pumping motion is effected by the swimmer 24. The higher profile is representative of the upward bending or bowing of the frame member 15 and the webbing material 17 as fluid resistance is encountered.
FIG. 3 is a rear view of the fluke or trailing edge 18 (FIGS. 1 and 3) of the flipper assembly, illustrating the cupping, bowing or arching action of the flexible webbing 17 between the frame or horn ends 12. As the user or swimmer 24 pumps his or her feet upward, the fluke 18 is displaced in a downward direction, as shown by the broken lines in FIG. 3. Downward movement of the flipper 11 moves the fluke 18 to arch in the manner shown by the solid lines in FIG. 3. FIG. 3 also illustrates the twisting of the horn ends 12. Depending upon the direction of the pumping motion, the horn ends 12 may be twisted in a clockwise or counterclockwise direction essentially about their axes. Inward bending of the frame member 15 is shown by broken lines in FIG. 4. Inward and upward bending and twisting of the frame member 15 may occur during each pumping motion effected.
The basic frame or horn member 15 is illustrated in FIG. 4. As the flipper 11 starts down from the high point of its pumping stroke, the frame member 15, due to its design, permits bending both upward and inward while twisting upwards along the inside edge. This flexibility permits the flipper fan section 19 to arch and increases the slingshot effect, imparting increased velocity to the captured water. Thus, the swimming apparatus of the invention traps a body of water within the fan section 19 and, with the proper hydrofoil cross-sectional configuration (FIGS. 9A, 9B and 9C), propels the water efficiently to the rear, as shown in FIG. 1OB.
In one embodiment, the material of the frame or horn member 15 is composed of lightweight tapered aluminum tubing construction having a diameter of about one inch at its widest portion. The fan section 19 may be formed of plastic materials such as Ren:C:0-Thane (trademark), produced by Smooth-on Corporation or rubber compounds.
FIGS. 5, 6 and 7 show different design variations or embodiments of the flipper 11. The embodiment of the flipper 29 of FIG. 5 includes a double slotted fluke construction. The flipper 29 has a pair of indentations 25 in the fluke trailing edge of the flipper assembly. Dorsal type fins 27 extend substantially longitudinally from the flipper 29.
FIG. 6 illustrates an embodiment of the flipper 31 having a wide fluke 33. The fluke trailing edge 33 extends considerably longer, in the embodiment of FIG. 6, than in the other embodiments. The frame member of the embodiment of FIG. 6 is thus designed for a broader expanse than in the other embodiments.
Aside from extending the width of the fluke, the invention may also be modified by extending the web length. This is illustrated in the embodiment of FIG. 7, wherein the flipper 35 includes a long web 39. The fluke trailing edge 37 of the embodiment of FIG. 7 is steeper than in the other embodiments, although a more straight edge may be used with the longer web, if desired.
FIGS. 9A, 9B and 9C are cross-sectional views taken at different parts of an embodiment of a flipper 28 of the invention in order to illustrate the preferred hydrofoil configuration for maximum efficiency of the swimming apparatus of the invention.
FIG. 1OA shows the swimmer 24 before reversal of kicking, in the upward direction, shown by an arrow 30. The lift is also in the direction of the arrow 30, so that the water flow is illustrated by arrows 32 and 34. The web 17 of the flipper 11 arches in the manner of the broken lines in FIG. 3. FIG. 10B shows the swimmer 24 after reversal of kicking, in the downward direction, shown by an arrow 36. The lift is also in the direction of the arrow 36, so that the water flow is illustrated by arrows 38 and 40. The web 17 of the flipper 11 arches in the manner of the solid line in FIG. 3.
FIGS. 10A and 10B illustrate how the swimming apparatus of the invention flexes to guide water into the pocket 26 to create a powerful water jet propulsive force. The cross-sectional hydrofoil configuration of the flipper 11 provides lift in both kicking directions and accelerates the flow of water into the pocket 26, which is formed by the bowing or arching action of the webbing 17 in motion. The flipper 11 has a spanwise hydrodynamic configuration for enhancing the entrapment of water and facilitating the flow of water into the pocket 26 and into a concentrated jet stream.
It will be obvious to those skilled in the art that various other modifications in the shape of the flipper may be made in order to minimize fluid dynamic drag. Likewise, variations of materials and the thickness thereof will affect the velocity of the stream of water which is pulsed to the rear by the cupping, bowing, or arching action of the flipper.
The objects and advantages of the invention are accomplished by the described flipper construction, which is stiff yet selectively flexible to have a relatively stiff leading edge and a more flexible webbing. The thickness and taper of the webbing may be selected with regard to the particular materials used in the structure and their characteristic flexibility. The material of the frame member should also be somewhat flexible to permit some degree of bending and twisting to permit the webbing to fully arch, bow or cup.
Spongy ankle socks may be incorporated in the interior of flipper apparatus to soften the interface between the feet of the user and the inner surface of the flipper.
The disclosed embodiments and other modifications and variations, such as those regarding the surface texture, buoyancy, angles of incidence, edge sweep and location of the foot pocket with respect to the fluke, fall within the scope of the invention, which is intended to be limited only by the appended claims which follow. Thus, although the foot pocket is shown in FIGS. 10A and 10B as being essentially for both feet of the swimmer in generally parallel relation with each other, it may be shaped to accommodate the feet of the swimmer in "pigeon-toed" relation with the toes of both feet closer to each other than the heels of the feet.
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Swimming apparatus for improved propulsion includes fluked foot flippers constructed to include a stiff load-bearing frame member in the leading edge of the fluke. As the flipper is pumped by the swimmer, a web secured to the frame member is caused to cup the flowing water by arching its surface. The flipper permits arching of the web and bending of the frame member both upward and downward, thereby creating a powerful stream of water propelled to the rear and resulting in a powerful propulsive forward thrust of the swimmer. The thrust is further enhanced by applying precisely formed hydrofoil cross-sectional or chordwise shaping to the fluke to accelerate the flow of water into the pocket. This flow also creates a lifting force which is in the direction of the fluke's motion and thus supports the kicking effort. In addition, spanwise hydrodynamic shaping serves to guide a greater volume of water into the pocket thereby further increasing the propulsive thrust.
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BACKGROUND OF THE INVENTION
This invention relates to a functionalized oligomeric lubricant additive which imparts enhanced anti-oxidancy and corrosion resistance upon dissolution in lubricating oils. More specifically, this invention relates to railway diesel lubricants and, more particularly, to diesel fuels containing anti-corrosion and anti-oxidation additives for improving the corrosion inhibition and anti-oxidation properties in motor fuels.
The past ten years have seen a dramatic increase in the cost of diesel fuel. For example, the price of marine diesel fuel has increased from approximately $11 a metric ton to a high of about $200 a metric ton. Additionally, a similar increase in fuel cost has been experienced by the railroad industry. The net effect of these price increases have resulted in the cost of fuel being the largest single operating expense for owners of any diesel fleet of vehicles. To try to obtain some relief, railroads have embarked on a program of mixing poorer grade fuels (such as marine residual) with regular D-2 diesel fuel. While they do realize a savings from this mixed fuel operation, performance problems arise, such as increased corrosion and poorer oxidative stability. The commitment to this mixed-fuel approach is reflected in General Electric's spending $20 million and while General Motors (EMD) also exerting a similar type of effort to determine optimum performance using mixed fuels.
Thus, the primary objective of this invention is to provide a novel railway diesel crankcase lubricating additive that enhances the oxidative corrosion resistant properties of these mixed fuels or oils.
DISCLOSURE STATEMENT
U.S. Pat. No. 3,773,479 discloses the use of the reaction product of maleic anhydride and alkyl or alkenyl amines as carburetor detergents, corrosive inhibitor, and as anti-icing additive in motor oils.
U.S. Pat. No. 4,089,794 discloses how the incorporation of ethylenically unsaturated carboxylic acid materials that have been post-reacted with a polyamine, polyol, or a hydroxylamine become effective as sludge control additive for lubricants.
U.S. Pat. No. 4,144,034 discloses the use of the reaction product of maleic anhydride and certain alkyl-alkylene diamines as a corrosion inhibitor and a carburetor detergent additive and corrosion inhibitor in motor fuels.
U.S. Pat. No. 4,290,778 discloses the use of the reaction product of an alkoxyalkylene diamine and maleic anhydride as a corrosion inhibitor and carburetor detergent additive in motor fuels.
U.S. Pat. No. 4,340,689 discloses a process for chemically grafting a functional organic group onto an ethylene-propylene copolymer or an ethylene-propylene-diene terpolymer.
U.S. Pat. No. 4,357,250 discloses a method of incorporating ethylenically unsaturated carboxylic acid or acid anhydrides onto oligomeric or U.S. Pat. No. 4,904,403 disclosed a method incorporating 1,3,4-thiadiazole onto an oligomeric or polymeric substrate as an anti-wear additive in lubricating oils.
The disclosures in the foregoing patents which relate to anti-oxidancy and anti-corrosion for lubricating oils, namely U.S. Pat. Nos. 3,773,479; 4,089,794; 4,144,034; 4,290,778; 4,340,689; 4,357,250; and 4,904,403 are incorporated herein by reference.
SUMMARY OF THE INVENTION
According to the present invention, it has been discovered that the dissolution of the imidization reaction product of oligomeric polyisobutylene containing one or more succinic anhydride or succinic acid moieties imidized with a polyalkylamine containing a diathiazole nucleus in oil causes two measurable and extremely desirable effect to the oil. Both these effects become apparent during engine operating conditions. The first effect pertains to enhanced oil oxidative resistance. This effect may be observed by measuring the oil viscosity. The second effect pertains to enhanced oil corrosion resistance. This effect may be observed by measuring the concentration of dissolved metallic ions such as lead, iron, copper, and tin contained in the oil.
The present invention provides a railway diesel crankcase lubricant composition comprising a major portion of a diesel lubricating oil and a minor amount of an oxidation and corrosion inhibiting agent. This condensate reaction product is prepared by the process comprising:
(a) reacting a dibasic acid anhydride of the formula ##STR1## where R 1 and R 2 is hydrogen or a (C 1 -C 10 ) linear or branched alkyl or cyclic alkyl group, separately, with
(i) a oligomeric isobutylene represented the formula: ##STR2## where the sum of the repeat units, b and c, are limited to the range of 10 to 500 so that the material has a corresponding molecular weight range from about 500 amu to 15,000 amu to produce oligomeric (isobutylene -g- succinic anhydride) and
(ii) 2,5-dimercapto-1,3,4,-thiodiazole represented by the formula: ##STR3## where R 6 is hydrogen or a (C 1 -C 10 ) linear or branched aliphatic hydrocarbon to produce 2-thio-(5-mercapto-1,3,4-thiadiazole) succinic anhydride;
(b) reacting the oligomeric (isobutylene-g-succinic anhydride) and the thiadiazole succinic anhydride with pentamethylene-diamine to produce the product of [2-thio-(5-mercapto-1,3,4-thiadiazole)] -[oligomeric (isobutylene g-succinic)] - pentamethylene- bis succinimide; and
(c) recovering said product bis-succinimide
DETAILED DESCRIPTION OF THE INVENTION
The present invention deals with the scenario where diesel fuel (D-2) is extended with diesel residual fuel, as proposed by the railroad industry. As a result, railway diesel oil (RDO) will be subjected to more severe conditions during operation. We have simulated the scenario wherein RDO is contaminated with a given amount of marine diesel residual fuel. We believe this to be a realistic test since during the normal engine operation D-2 gets into the diesel crankcase. Finally, the Union Pacific Oxidation Test (UPOT) was used to evaluate the effectiveness of the experimental additives impeding corrosion and oxidative thickening of the RDO.
The pentamethylenediamine may be substituted with a N-alkyl alkyene diamine having the structural formula: ##STR4## where R' is a hydrogen or a (C 1 to C 10 ) hydrocarbon group and R 3 , R 4 and R 5 is hydrogen or a (C 1 to C 10 ) hydrocarbon group, is an integer between 0 and 7.
The heterocyclic 1,3,4-thiadiazole nucleus of the present invention is structurally represented as: ##STR5## where R 6 is hydrogen or a (C 1 -C 10 ) linear or branched aliphatic alcohol or amine.
The dibasic acid or anhydride os this invention may be represented by the structural formula: ##STR6## where R 1 and R 2 is hydrogen or a (C 1 -C 10 ) linear or branched alkyl or cyclic alkyl structure. Dibasic anhydrides amenable to this process include maleic anhydride; alpha-methyl maleic anhydride; alpha,beta dimethyl maleic anhydride; alpha, beta dimethyl maleic anhydride; alpha-ethyl maleic anhydride; 2alpha,beta-di-n-propyl maleic anhydride; alpha-n-hexyl maleic anhydride; alpha, beta-di-n-hexyl maleic anhydride; alpha-n-nonyl nonyl maleic anhydride; alpha, beta-di-n-octyl maleic anhydride; alpha, beta-di-n-nonyl maleic anhydride.
The preferred dibasic acid anhydride is maleic anhydride. The polyalkylated alkylimide of 1,3,4-thiadiazole wherein a is 1, the sum of b and c is approximately 25, and where R 1 , R 2 , R 3 , R 4 , R 5 and R 6 are hydrogen is available from R. T. Vanderbilt Company, Inc., of Norwalk, Conn. under the Tradename of OCD-077.
This invention is also directed to a marine crankcase lubricant composition containing the prescribed polyalkylated alkylimide of 1,3,4-thiadiazole which exhibit substantially reduced oxidation and corrosion tendencies.
The reaction product of this invention is prepared by a multistep process. Initially, oligomeric butylene represented by the formula, ##STR7## viz., oligomerized 1,3-butadiene containing a mixed and random 1,2- and 1,4- repeat unit where the sum of the repeat units, b and c, are limited to the range of 10 to 50 so that the material has a corresponding molecular weight range of from 500 amu to 15,000 amu, is reacted with an ethylenically unsaturated acid or, more preferably, an acid anhydride.
The preferred method of incorporation of maleic anhydride onto the oligomeric polyisobutylene is through the "ene" reaction. During this preferred method, oligomeric isobutylene and approximately 0.05 wt% to 5.00 wt% maleic anhydride are heated in the presence or absence of an inert reaction solvent. Heating is continued for a sufficient time to ensure that at least 95 wt% of the anhydride becomes chemically incorporated onto the oligomeric substrate, typically 0.5 hrs to 3.0 hrs. The molecular weight of the oligomeric substrate may range from about 300 amu to about 15,000 amu. In no case, however, will the molecular weight of the polymeric substrate influence the ene reaction kinetics.
Examples of oligomeric olefins amenable to the ene reaction include those derived from alpha-olefin monomers such as isoprene, isobutene, 2-methyl-n-heptene, 2,4-dimethyl-nheptene, and the like.
The preferred oligomeric olefin is oligomeric butylene, however, and is available from the Amoco Chemical Company under the tradename ACTIPOL.
These above ene reaction intermediates are imidized using the imidization reaction product of an N-alkyl-alklene diamine, and maleic anhydride and 2,5-dimercapto-1,3,4-thiadiazole.
The amines which may be employed in the present process include polyamines, preferably diamines, which bear at least two primary amine-NH2 groups and at least one amine groups. The latter may be mono- or di-substituted by linear or branched aliphatic hydrocarbons.
The preferred amine has the structural formula: ##STR8## wherein R' is hydrogen or a (C 1 -C 10 ) hydrocarbon group and R 3 , R 4 , and R 5 each are hydrogen or a (C 1 -C 10 ) hydrocarbon group, and a is an integer between 0 and 7.
The preferred N-primary alkylalkylkene diamines include tetra-ethylenediamine, pentaethylenediamine, and hexaethylenediamine.
In accordance with the present invention, the process comprises the addition to the hydrocarbon fuel, of a minor deposit-inhibiting amount of, as a deposit-inhibiting additive, a reaction product of (a) an oligomeric olefin, (b) maleic anhydride, and (c) an N-alkyl-alkylene diamine and a 1,3,4-thiadiazole.
The synthetic process proceeds in three Phases and is summarized below, and then illustrated by a flow diagram.
Phase I
In this initial synthetic phase, maleic anhydride (A) is reacted with oligomeric olefins (B) to form the succinic anhydride adduct (C).
Phase II
In this second phase, equimolar amounts of maleic anhydride (A) and 2,5-dimercapto-1,3,4-thiadiazole (D) are reacted together to form a second succinic anhydride adduct (E).
Phase III.
This is the coupling phase. In this phase reaction intermediates (C) and (E) are imidized using an N-alkyl alkyene diamine (F) to form a mixed imidization product (G). ##STR9##
The following examples are provided to illustrate the preferred method of preparing the present reaction product and the effectiveness of the product in railway diesel crankcase lubricants. It will be understood that the following examples are merely illustrative and are not meant to limit in any way the invention.
EXAMPLE I
Preparation Of Oligomeric(Isobutylene-g-Succinic Anhydride)
In a preferred method for preparing the reaction product, maleic anhydride and oligomericisobutylene with an Mn= 900 are mixed together in toluene and heated to solvent reflux temperature for 5 hours under an inert and anhydrous atmosphere, such as nitrogen. The reagent weight ratios are chosen so that 0.10 wt % to 0.50 wt % of maleic anhydride is grafted to the oligomeric substrate to produce the oligomeric (isobutylene-q-succinic anhydride).
EXAMPLE II
Preparation Of 2-Thio-(5-Mercapto-1,3,4-Thiadiazole)-Succinic Anhydride
In the preferred method for preparing this product, equimolar amounts of 2,5 dimercapto-I,3,4-diathiazole and maleic anhydride are dissolved in I:1 v/v toluene and tetrahydrofuran and heated to reflux temperature for approximately 6 hours under a protective blanket of nitrogen. pressure and a yellow resinous material isolated to form 2-thio-(5-mercapto-1,3,4-thiadiozole)-succinic anhydride.
EXAMPLE III
Coupling Product Of 2-Thio-(5-Mercapto-1,3,4-Thiadiazole)Succinic Anhydride And Olioomeric(Isobutylene-g-Succinic Anhydride) Using Pentamethylenehexaamine
2-thio-(5-mercapto-1,3,4-thiadiazole)-succinic anhydride and oligomeric(isobutylene-g-succinic anhydride) are dissolved in toluene so that a 1:1 molar ratio of reagents is obtained. Moreover, the solute concentration ideally remains under 50 wt % to avoid agitation problems associated with high solution viscosity. Sufficient pentamethylenehexaamine is added to the mixture as to cause complete imidization of all anhydrides present. The reaction mixture is heated to reflux temperature for 10 hours under an inert atmosphere to yield the coupling product of the succinic anhydrides of Examples I and II, i.e., [2-thio-(5-mercapto-1,3,4-thiadiazole)] - oligomeric (isobutylene-q-succinic)]-penta-methylenetetraamine-bissuccinimide.
The preferred components of the railway diesel crankcase lubricating oil composition of the present invention are those which are effective in a range of from about 0.1 to about 5 wt % based on the total lubricating oil composition. However, it is economically preferred to employ from about 0.5 to 2.0 wt % of the derivative based on the weight of the lubricating oil with the most preferred concentration being between 0.75 to about 1.5 wt %.
The experimental additive was dissolved in railway diesel crankcase lubricating oil and evaluated using the UPOT test.
The railway diesel crankcase lubricating oil consisted of a mixture of two components, a major component and a minor component. A description of each component is summarized below:
(a) a major portion of a liquid paraffinic mineral oil having a viscosity at 100° C. of about 52.5 SUS, at
100° C. of about 75.0 to 79.0 SUS and a liquid naphthenic mineral oil having a viscosity at 100° C. of about 75.0 to 80.0 SUS; and
(b) a minor component of, as an oxidation and corrosion inhibiting agent, a condensate product prepared as mentioned earlier from the reaction of a oligomeric isobutylene, maleic anhydride, 2,5-dimercapto 1,3,4-thiadiazole, and an N-alkyl-alkylene diamine.
OIL OXIDATION TEST
The test method involves bubbling 5 liters of oxygen per hour through 300 mls of test oil composition at 285° F. in which there is immersed a 1"×3"×0.06 inch steel -backed copper-lead test specimen, cut from bearing stock. The viscosity of the test oil is measured before and after the 144 hour test period where the greater the differences between these two viscosities is indicative of higher oxidation levels. Moreover, the test specimen is weighed before and after the test period where the greater the weight loss the greater is the corrosion in the formulation. And, further, the larger the amount of copper, lead, and iron moieties found in the oil after the test, the greater the oxidation/corrosion deterioration thereof.
The representative Formulations A,B and comparative Formulation C and their oxidation test results are reported below in Table I.
TABLE I______________________________________Summary Of Union Pacific Oxidation Test ResultsAfter 144 Hours At 285° F. UNTREATED TREATEDComposition, Wt % (A) (B) (C)______________________________________SNO-20 5.00 5.00 5.00SNO-40 48.30 48.30 48.3075/80 Pale Oil 37.00 37.00 37.00PC-140* 5.55 5.55 5.55TC-9596A** 4.05 4.05 4.05Chlorowax 500° C. 0.05 0.05 0.05TC-10314** 0.05 0.05 0.05TX-1416*** 150 150 1.50Experimental Additive -- 1.00 2.00Union Pacific OxidationTestWeight Loss, mg. 280 3.1 2.0Viscosity Increase, %. 160 67.0 59.0______________________________________ *(PC-140) is a phenolic stabilizing agent; **(TC9596A and TC10314) and ***(TX1416) are, respectively, aromatic and dialiphatic Mannichbase antioxidants; and all PC, TC and TX products are manufactured and sold by Texaco Chemical Company of Houston, Texas.
It is evident from the above results, that the incorporation of 1wt %, or 2wt. % of the oligomeric additive causes enhanced anti-oxidative and corrosive resistance to be imparted to the railway oil.
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A railway diesel crankcase lubricant composition comprising a major portion of a diesel lubricating oil and a minor amount of, as an oxidation and corrosion inhibiting agent, a condensate product prepared by the process comprising:
(a) reacting a dibasic acid anhydride, separately, with:
(i) a oligomeric isobutylene, and
(ii) 2,5-dimercapto-1,3,4,-thiadiazole, to produce, respectively, oligomeric(isobutylene-g-succinic anhydride) and 2-thio-(5-mercapto-1,3,4-thiadiazole) succinic anhydride;
(b) reacting both of the succinic anhydrides with pentamethylenediamine to produce the [2-thio-(5-mercapto-1,3,4-thiadiazole)]-[oligomeric(isobutylene-g-succinic)]-pentamethylenetetraamine-bis succinimide product; and
(c) recovering the bis-succinimide product.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This is a continuation-in-part of copending application Ser. No. 07/716,032, filed Jun. 14, 1991, now U.S. Pat. No. 5,267,564.
FIELD OF THE INVENTION
The present invention relates generally to implantable pacemaker leads, and more particular, to a multipolar in-line proximal connector assembly for an implantable pacemaker lead that can sense at least one physiologic parameter of the body.
BACKGROUND
An implantable stimulation lead is a medical device that delivers stimulation pulses from an implanted pulse generator to the heart, or other body tissue, for the purpose of causing a desired muscle contraction. For cardiac muscle stimulation, such lead is typically inserted through one of the main veins of the patient, e.g., the superior vena cava, so that a distal end of the lead may be directed inside the heart. Electrodes positioned at the distal end of the lead make contact with the cardiac tissue. Implantable stimulation leads may be classified as being unipolar (having a single tip electrode), bipolar (having a tip electrode and a ring electrode), or multipolar (having three or more electrodes).
As used herein, the distal end of the implantable stimulation lead is that end which makes electrical contact with the heart and the proximal end is that end which is connected to the pacemaker through a connector top. Hereinafter, the proximal end of the implantable stimulation lead will be referred to as the "proximal connector assembly". The proximal connector assembly typically takes the form of a male connector, with the pacemaker connector top taking the form of a female connector. When joined, good electrical contact must be maintained between the terminals of the proximal connector assembly and an appropriate feedthrough terminal of the pulse generator housing. Furthermore, such lead connection must be secure, so that it does not disconnect during use, yet detachable in the event the pulse generator or lead needs to be replaced. Moreover, such connections must at all times remain insulated and sealed from ionic body fluids, which body fluids are conductive and could cause an electrical short.
With the arrival of dual chambered pulse generators, it was necessary to have two female connectors within the connector top to accommodate two leads. Thus, it is preferable for bipolar leads to have an "in-line" lead assembly (as opposed to a "bifurcated" lead assembly) to minimize the height of the connector. For example, U.S. Pat. No. 4,951,687 (Ufford et al.) and U.S. Pat. No. 4,572,605 (Hess) show in-line bipolar proximal lead assemblies with and without sealing rings, respectively, made using conventional techniques. That is, these bipolar leads included a pin terminal and a ring terminal coupled to a distal tip and ring electrode, respectively, by coaxial conductors. The electrical connection to the pin terminal is made by isolating and stretching the inner coil of the coaxial conductor over the pin terminal and either crimping or welding it thereto. The electrical connection to the ring terminal is similarly made by isolating and fixturing the outer coil of the coaxial conductor onto the ring terminal and crimping or welding it thereto. Once connected the whole assembly is then injection molded in a body compatible material. However, many of the existing methods and techniques are no longer suitable for the smaller pulse generators and leads that are currently being used.
Currently, there has been a tremendous demand to incorporate physiologic sensors onto the implantable stimulation lead. These sensors will measure a variety of physiologic parameters, such as, blood oxygen saturation, blood pressure, ejection time, pH, temperature, impedance, heart wall motion, etc. The additional sensor typically requires two additional conductors and proximal terminal contacts. However, the need for additional terminal contacts also requires additional space for isolation and for enabling the crimp or weld procedure.
In anticipation of these sophisticated leads, there have been several attempts at manufacturing "tripolar" leads, that is, leads having three distal electrodes. For example, U.S. Pat. No. 4,469,104 (Peers-Trevarton) shows a lead assembly having three spaced apart metal bands with resilient conductive rings on each band adapted to make contact with a corresponding ring terminal in the connector top. U.S. Pat. No. 4,469,104 (Doan et al.) also shows, in one embodiment, a tripolar lead assembly. However, neither embodiment is easily expandable to include four or more terminals. Furthermore, each of these lead assemblies are specially designed for each manufacturer's pulse generator connector top.
Furthermore, over the approximately 30 year history of the implantable pulse generator, a wide variety of techniques and methods have been used to connect leads to pulse generators. During that time, almost no standardization existed for their dimensions. While some manufacturers strongly believed that the sealing mechanism belonged on the lead in the form of seal rings, another group preferred to have the seal rings inside the pulse generator's connector top with a smooth sealing surface located on the lead. Great variability in the actual dimensions existed even with the standard "5 mm" or "6 mm" leads available from different manufacturers. As the pulse generator electronics and batteries become smaller, the connector system represents a larger percentage of the total pulse generator volume. Thus, many manufacturers are contemplating smaller connector systems.
To avoid a proliferation of new and incompatible designs, a major effort has been underway to standardize the interface between an implantable stimulation lead and a pulse generator. The proposed voluntary standard, known as VS-1, has subsequently been adopted by almost all pulse generator manufacturers worldwide. The VS-1 standard does not specify how a particular pulse generator connector must make contact with a implantable stimulation lead, it simply defines the dimensions of the 3.2 mm implantable stimulation lead and the dimensions of the corresponding pulse generator connector cavity into which the implantable stimulation lead is inserted. The VS-1 standard further specifies certain requirements as to leakage, conductivity and connect/disconnect force. For a further explanation of the VS-1 Standard, reference is made to "A Voluntary Standard for 3.2 mm Unipolar and Bipolar Implantable Stimulation Leads and Connectors," Calfee et al., PACE. Vol. 9, 1181-85 (Nov.-Dec. 1986), which reference is hereby incorporated herein by reference.
While the VS-1 standard advantageously represents a long needed movement towards industry standardization, the VS-1 standard disadvantageously restricts the dimensions of the proximal connector assembly of the implantable lead, which can in turn limit the number of conductors and terminals.
What is needed, therefore, is a multipolar implantable stimulation lead which meets the VS-1 standard, is easy to manufacture, and can be readily expanded to include many terminals and conductors without increasing its diameter and without excessively increasing the proximal connector assembly length (which in turn would affect the pacemaker connector top dimensions). It is also an objective that all of the aforesaid advantages and objectives be achieved without incurring any substantial relative disadvantage.
SUMMARY OF THE INVENTION
It was in light of the foregoing that the present invention has been conceived and is now reduced to practice. The present invention is directed toward an in-line, quadrapolar (four electrodes) proximal connector assembly for an implantable stimulation lead which incorporates at least one sensor. In the preferred embodiment, the sensor requires electrical connection between the pacemaker and at least two (2) sensor terminals. Thus, the lead of the preferred embodiment includes four conductors, a proximal pin terminal and three proximal ring terminals corresponding to a distal tip electrode, a distal ring electrode and two sensor electrodes. The lead body comprises a body compatible tubing with at least four lumens, or holes, for insulating the four conductors.
In the proximal connector assembly of the preferred embodiment, the pin terminal is electrically connected to a conductive tube, which extends out of the distal end of the proximal connector assembly. The channel in the conductive tube serves to direct a guidewire or stylet through the proximal connector. Each of the three ring electrodes is electrically connected to a straight conductor wire which also extends out of the distal end of the proximal connector assembly. The distal ends of the conductive tube and the conductor wires are advantageously electrically connected to multifilar conductors within a multilumen lead body by splicing, welding, or other similar process. In the preferred embodiment, the pin terminal, the three ring terminals, the conductive tube and the three conductor wires are insert molded with body compatible material into a unified body. Seal rings may be molded onto the proximal connector assembly or added after the molding process.
Advantageously, the present invention uses straight conductive wires to electrically connect the proximal terminals to the conductors in the lead body. It is the use of straight rods (as opposed to coiled conductors) that enables the diameter of the lead assembly to remain small. Additional terminals can easily be added by simply decreasing the spacing between terminals and adding additional straight conductive rods.
In an alternate embodiment, the proximal connector assembly also includes a plurality of preformed insulators dimensioned so as to slidably interlock the proximal terminals. Advantageously, the preformed insulators are designed to self-position the terminals according to precise dimensions defined by the VS-1 (or other) standards. More specifically, three premolded insulating spacers include recesses dimensioned so as to prevent the ring terminals from sliding axially out of position. The length of the spacers serves to position the ring terminals a precise distance from the pin terminal.
In alternate embodiments, the present invention may be expanded to include a plurality of ring terminals so that more than two sensor connections may be incorporated into the lead. In addition, it may be readily seen that the present invention may also be employed in a standard bipolar or tripolar lead to enhance manufacturability of the proximal lead connector. In each configuration (bipolar, tripolar, quadrapolar or other multipolar), the present invention maintains the same connector diameter as the present VS-1 standard bipolar configuration.
The present invention further includes two methods of making a multipolar proximal connector assembly. Both methods include the steps of pre-attaching a pin terminal to a conductive tube, a first conductive rod to a first ring terminal, and a second conductive rod to a second ring terminal. In the preferred embodiment, the method includes insert-molding the pin terminal and the first and second ring terminals (with their respective pre-attached tubes and rods) with body compatible material to produce a unified proximal connector assembly. Additional ring electrodes (with rods pre-attached) may be easily added by shortening the distance between terminals during the molding step. In an alternate embodiment, the method includes replacing the body compatible material with premolded spacers which interjoin or interlock the terminal together.
Thus, the present invention enables a secure yet detachable connection between an implantable lead and the pacemaker connector top, while also providing greatly improved and accelerated assembly of the proximal connector assembly, increased reliability of the terminal connections, and the ability to expand to a plurality of poles maintaining the same lead diameter.
Other and further features, advantages and benefits of the invention will become apparent in the following description taken in conjunction with the following diagrams and drawings. It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory, but are not to be restrictive of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings which are incorporated in and constitute a part of this invention illustrate one of the embodiments of the invention, and together with the description serve to explain the principles of the invention in general terms.
FIG. 1 is a cross-sectional view of a pin terminal;
FIG. 2 is an end view of the pin terminal shown in FIG. 1 taken across the lines 2--2;
FIG. 3 is a cross-sectional view of a conductive tube;
FIG. 4 is a plan view of a first ring terminal;
FIG. 5 is an end view of the first ring terminal shown in FIG. 4 taken across the lines 5--5;
FIG. 6 is a cross-sectional view of the first ring terminal shown in FIG. 4 with a straight conductive wire connected thereto;
FIG. 7 is a plan view of the second (or third) ring terminal;
FIG. 8 is an end view of the second (or third) ring terminal taken across the lines 8--8;
FIG. 9 is a cross-sectional view of the second (or third) ring terminal shown in FIG. 7 with a straight conductive wire connected thereto;
FIG. 10 is a cross-sectional view of a first seal ring;
FIG. 11 is a plan view of the first seal ring shown in FIG. 10;
FIG. 12 is a plan view of a second seal ring;
FIG. 13 is a cross-sectional view of the second seal ring shown in FIG. 12;
FIG. 14 is a cross-sectional view of the MULTIPOLAR IN-LINE PROXIMAL CONNECTOR ASSEMBLY of the preferred embodiment of the present invention;
FIG. 15 is a cross-sectional view of the proximal connector assembly shown in FIG. 14 taken across the lines of 15--15;
FIG. 16 is another cross-sectional view of the proximal connector assembly shown in FIG. 14 taken across the lines of 16--16;
FIG. 17 is a cross-sectional view of the proximal connector assembly shown in FIG. 14, rotated 90 degrees and connected to a lead body and a connector boot;
FIG. 18 is a plan view of the proximal connector assembly of the present invention;
FIG. 19 is a plan view of the proximal connector assembly of the present invention connected to a lead body and a connector boot;
FIG. 20 is a cross-sectional view of a first premolded insulating spacer;
FIG. 21 is an end view of the first premolded insulating spacer shown in FIG. 20 taken across the lines of 21--21;
FIG. 22 is a cross-sectional view of a second premolded insulating spacer;
FIG. 23 is an end view of the second premolded insulating spacer shown in FIG. 22 taken across the lines of 23--23;
FIG. 24 is a cross-sectional view of a third premolded insulating spacer;
FIG. 25 is an end view of the third premolded insulating spacer shown in FIG. 24 taken across the lines of 25--25;
FIG. 26 is a cross-sectional view of a fourth premolded insulating spacer;
FIG. 27 is an end view of the fourth premolded insulating spacer shown in FIG. 26;
FIG. 28 is a second embodiment of the multipolar in-line proximal connector assembly using the first, second and third insulating spacers shown in FIGS. 20-27;
FIG. 29 is a cross-sectional view of the proximal connector assembly shown in FIG. 28, rotated 90 degrees;
FIG. 30 is a cross-sectional view of a first insulating tube;
FIG. 31 is an end view of the first insulating tube shown in FIG. 30 taken along the lines of 31--31;
FIG. 32 is another cross-sectional view of the first insulating tube shown in FIG. 31 taken along the lines of 32--32;
FIG. 33 is a cross-sectional view of a second insulating tube;
FIG. 34 is an end view of the second insulating tube shown in FIG. 33 taken along the lines of 33--33;
FIG. 35 is another cross-sectional view of the second insulating tube shown in FIG. 34 taken along the lines of 35--35;
FIG. 36 is a cross-sectional view of a third insulating tube;
FIG. 37 is an end view of the third insulating tube shown in FIG. 36 taken along the lines of 37--37;
FIG. 38 is another cross-sectional view of the third insulating tube shown in FIG. 36 taken along the lines of 38--38;
FIG. 39 is a cross-sectional view of a fourth insulating tube;
FIG. 40 is an end view of the fourth insulating tube shown in FIG. 39 taken along the lines of 40--40;
FIG. 41 is another cross-sectional view of the fourth insulating tube shown in FIG. 40 taken along the lines of 41--41;
FIG. 42 is a third embodiment of the multipolar in-line proximal connector assembly using the insulating spacers and the insulating tubes shown in FIGS. 20-27 and 30-31, respectively;
FIG. 43 is a cross-sectional view of the proximal connector assembly shown in FIG. 42, rotated 90 degrees;
FIG. 44 is a cross-sectional view of multipolar in-line proximal connector assembly which includes 5 ring terminals;
FIG. 45 is a cross-sectional view of the proximal connector assembly shown in FIG. 44, rotated 90 degrees;
FIG. 46 is a cross-sectional view of the proximal connector assembly shown in FIG. 44 taken along the lines of 46--46; and
FIG. 47 is a side view of the body implantable lead of the present invention with a sensor mounted therein.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following description is of the best mode presently contemplated for practicing the invention. This description is not to be taken in a limiting sense, but is made merely for the purpose of describing the general principles of the invention. The scope of the invention should be ascertained with reference to the issued claims. In the description of the invention that follows, like numerals or reference designators will be used to refer to like parts or elements throughout.
While the present invention was conceived during the development of a multipolar proximal connector assembly for an oxygen saturation sensing lead, it is to be understood that the present invention could be used with any remote sensor located on an implantable lead. Since oxygen saturation sensors have typically required two additional conductors, the present invention is directed toward a quadrapolar (four conductors) proximal connector assembly. For a complete description of an oxygen saturation lead, reference is made to copending U.S. patent application Ser. No. 07/716,032, entitled "Pacemaker Lead for Sensing a Physiologic Parameter of the Body," filed 6/14/91, which application is hereby incorporated herein by reference.
FIGS. 1 and 2 show a detailed cross-sectional view and an end view of a pin terminal 10. The pin terminal 10 has a channel 12 through which a guidewire or stylet may be passed during implantation. To facilitate the insertion of the guide wire, the channel 12 has a flanged end 14. The pin terminal 10 has a recess 16 at the other end dimensioned to receive a conductive tube (not shown). The pin terminal 10 also has a narrow neck portion 18 where the pin terminal 10 is designed to have seal rings (not shown) attached or molded thereon. It is understood that the narrow neck area 18 may include some type of gripping means, such as ridges or grooves, to help adhere the seal rings to the pin terminal 10.
In FIG. 3, a cross-sectional view of a conductive tube 20 is shown to include a channel 22 extending therethrough for passing the guide wire or stylet. The outer diameter of the channel 20 is dimensioned to be slidably inserted within the recess 16 (FIG. 1) of the pin terminal 10. The conductive tube has a slight bend in the area of 24, the purpose of which will be described in conjunction with other Figures.
In FIGS. 4, 5 and 6, a first ring terminal 30, made of conductive material, is shown having a main body 32 (which provides a large contact area for connection to the pacemaker receptacle) and a first and second protruding portions 34, 36, respectively, at either end. A plurality of holes 38 located around the first and second protruding portions 34, 36 are used to grip silicone rubber, or other adhesives, used to bond the final assembly together. Extending through the first ring terminal 30 is a channel 40 (FIG. 6). In FIG. 6, a conductive wire 42 is also shown attached to the first ring terminal 30 at location 44 of the channel 40.
FIGS. 7, 8 and 9 show a plan, end and cross-sectional view, respectively, of a second ring terminal 50. The second ring terminal is shown having a main body 52 which provides a large electrode surface area for contact with bodily fluids. In the preferred embodiment, the main body 52 is approximately 1/2 the length of the main body 32 of the first ring terminal 30. However, it is also recognized that the length of the second (and other additional) ring terminals can be made even smaller to accommodate a plurality of terminals in the same proximal connector assembly and is limited only by the pacemaker connector technology. The length of the main body 52 is currently designed to align with a standard garter spring connector, as is known in the art.
The second ring terminal 50 also includes a protruding portion 54 at one end. A plurality of holes 58 located around the first protruding portion 54 is used to grip silicone rubber, or other adhesive, which is used to bond the final assembly together. Extending through the second ring terminal 50 is a channel 60. In FIG. 9, a conductive wire 62 is also shown attached to the second ring terminal 50 at location 64 of the channel 60. A distal end 66 of the conductive wire 62 is bent slightly and welded, or otherwise attached, to the second ring electrode 50.
In the preferred embodiment, the third ring terminal is identical to the second ring terminal 50. To distinguish the third ring terminal, a prime (') will be used for corresponding elements, e.g., a third ring terminal 50' includes a main body 52' having a protruding portion 54' with a plurality of holes 58', etc.
In the preferred embodiment, two seal rings are used on each proximal connector assembly. A first seal ring 70, shown in FIGS. 10 and 11, has a main body 72 with a channel 74 dimensioned to fit around the narrow neck portion 18 of the pin terminal 10. Two o-rings 76 are dimensioned to form a tight seal within the pacemaker connector top. Thus, the first seal ring 70 prevents bodily fluids from creating a low impedance leakage pathway between the pin terminal and the ring electrode.
A second seal ring 80, shown in FIGS. 12 and 13, has a main body 82 with a channel 84 dimensioned to fit around the one of the protruding portions of the first ring terminal, either 34 or 36, which ever is most distal from the pin terminal. Two o-rings 86 are dimensioned to form a tight seal within the pacemaker connector top. Thus, the second seal ring 80 provides a second barrier against bodily fluids.
In conjunction with FIGS. 14, 15, 16 and 17, the method of assembly will now be described. In the preferred embodiment, the conductive tube 20 is slid into the recess 16 of pin terminal 10 and welded, or otherwise electrically attached, thereto. The first ring terminal 30, with the conductive wire 42 pre-attached, is then slid over the conductive tube 20. Next, the second ring terminal 50, with the conductive wire 62 (not shown) pre-attached, is slid over the conductive tube 20. Likewise, the third ring terminal 50', with the conductive wire 62' pre-attached, is slid over the conductive tube 20. The terminals (10, 30, 50 and 50'), the conductive tube 20 and the conductive wires (42, 62 and 62') are then placed in a precision mold and injected with body compatible material to produce the proximal connector assembly shown in FIG. 14. Suitable materials include the polyurethane material sold under the trademark PELLATHANE and manufactured by Dow, or an elastomer material manufactured by Dow Corning, such as Elastomer #Q7-4765, or equivalent type of silicone rubber. The body compatible material flows into the holes 38, 58 and 58' in the ring terminals 30, 50 and 50', respectively, which improves the mechanical strength and the bonding between the body compatible material and the terminals. The body compatible material also flows into molded portions 92, 94, 96 and 98.
Advantageously, conductive wires 42, 62 and 62' are straight wires made of a resilient, noncorroding metal, preferably MP35N alloy. This configuration thereby eliminates unnecessary bulk in the multipolar proximal connector assembly 90. Preferably, each of the conductor wires 42, 62 and 62' is electrically insulated from each by a thin polymer insulative coating. The insulative coating may be one of the polymer materials sold under the trademarks TEFLON and TEFZEL, manufactured by DuPont, which materials have good electrical insulating properties without adding significant bulk.
In the preferred embodiment, the conductive tube 20, together with the first, second and third ring terminals 30, 50 and 50', enable a stiffer body construction so that the conductive wires 42, 62 and 62' are not subject to excessive stresses which would cause fatigue and breakages. In FIGS. 14 and 17, the proximal connector assembly is shown prior to attachment of the first and second seal rings 70 and 80.
FIG. 17 further shows the proximal connector assembly 90 connected to a multilumen lead body 100 and a connector boot 102. In this partial cross-sectional view, the conductive wires 62 and 62, are clearly seen extending out of the distal end of the proximal connector assembly 90. The multilumen lead body 100 has four coiled conductors which are dimensioned to receive the conductive wires 42, 62, 62' and the conductive tube 20, respectively, therein. While FIG. 17 only shows two of the four conductors (104 and 106), each of the conductors is attached to the proximal connector assembly 90 in similar fashion. For example, conductive wire 62 is advantageously dimensioned to be slidably inserted within the coiled conductor 104 and then welded, crimped, or otherwise electrically attached thereto. The multilumen lead body 100 is then slid over the spliced area 110.
The connector boot 102 may be attached in a variety of ways. For example, the connector boot 102 may be preformed, stretched and then slid over the spliced area 110 to provide additional stiffness and protection against fatigue and breakages. Alternately, the connector boot 102 may be expanded by soaking it in a solvent such as isopropyl alcohol or the material sold under the trademark FREON and manufactured by Dupont.
FIGS. 18 and 19 are simply plan views of the proximal connector assembly 90 corresponding to FIGS. 14 and 17, respectively. In FIG. 19, the first and second seal rings 70, 80 are also shown attached, which attachment may be accomplished in a variety of ways. For example, the seal rings 70, 80 may be preformed, stretched and then slid into place. Alternately, the seal rings 70, 80 may be expanded by soaking them in a solvent such as isopropyl alcohol or the material sold under the trademark FREON and manufactured by Dupont, and then slid into place. In another embodiment, the seal rings 70, 80 may be insert molded together with the pin terminal 10 and the first, second and third ring terminals 30, 50, 50'. Seal rings could also be placed between electrical contacts 50 and 50', and between electrical contact 50' and the body. However, in the preferred embodiment, these seal rings are located within a pacemaker's connector top.
In an alternate embodiment, the injection molded portions of the proximal connector assembly 90 are replaced by a plurality of premolded insulating spacers which are dimensioned to self-position each of the terminals a precise distance from each other. More specifically, the injection molded portions 92, 94 and 96 shown in FIG. 18 may be replaced with a first, a second, and a third premolded insulating spacer 140, 150 and 160, as shown in FIGS. 20-21, 22-23, 24-25, respectively.
As shown in FIGS. 20-21, the first insulating spacer 140 includes a main body 142 with a first recess 144 for receiving the one end of the pin terminal 10. The first insulating spacer 140 further includes a second recess 146 for receiving the first protruding portion 34 of the first ring terminal 30.
In FIGS. 22-23, the second insulating spacer 150 includes a main body 152 and a protruding portion 154. The protruding portion 154 has a recess 156 therein for receiving the second protruding portion 36 of the first ring terminal 30. The main body 152 includes a recess 158 for receiving the protruding portion 54 of the second ring terminal 50.
In FIGS. 24-25, the third insulating spacer 160 includes a main body 162 and a protruding portion 164. The third insulating spacer 160 includes a channel 166 for passing the conductive wires 42, 62 and the conductive tube 20 therethrough. The outer diameter of the protruding portion 164 is, advantageously, dimensioned to fit within the channel 60 of the second ring terminal 50. The main body 162 includes a recess 168 dimensioned to receive the protruding portion 54' of the third ring terminal 50'.
In the preferred embodiment, a fourth insulating spacer 170 (shown in FIGS. 26 and 27) is inserted within the first insulating spacer to insulate and self-position the pin terminal 10 a precise distance from the first ring terminal 30. The fourth insulating spacer includes a channel 172 for passing the conductive tube 20. However, it is recognized that the fourth insulating spacer 170 could be integrally formed in the first insulation spacer 140.
The proximal connector assembly 190, which employs the plurality premolded insulating spacers 140, 150 and 160, is shown in FIGS. 28 and 29. FIG. 28 is a cross-sectional view corresponding to the view shown in FIG. 14 of the preferred embodiment. FIG. 29 is a cross-sectional view rotated 90 degrees, with the conductive tube omitted for clarity.
In one embodiment, the proximal connector assembly 190 is injection molded with body compatible material, such as silicone rubber, in the inner cavity where the conductive tube 20, the conductive wires 42, 62, and 62' reside, thus, insulating them from each other. In addition, the conductive wires would preferably have a thin insulative outer coating, such as the polymer materials sold under the trademarks TEFLON and TEFZEL, manufactured by DuPont, which materials have good electrical insulating properties without adding significant bulk.
In another embodiment, a plurality of premolded insulating tubes are used to fill and electrically isolate the conductive tube 20 and the conductive wires 42, 62, and 62' from each other. A first insulating tube 210 is shown in FIGS. 30-41.
The first insulating tube 210 has a main channel 212 and a slot 214, as shown in FIGS. 30-32. The slot 214 is dimensioned to slidably fit the conductive wire 42 therein so that the conductive wire 42 may make electrical contact with the first ring terminal 30. The main channel 212 is dimensioned to slidably fit the conductive tube 20 therein. The outer diameter of the first insulating tube 210 is dimensioned to slidably fit within the first ring terminal 30.
FIGS. 33-35 show a second insulating tube 220 having a main channel 222, a channel 224 and a slot 226. The main channel 222 is dimensioned to receive the conductive tube 20 therein. The channel 224 is dimensioned to pass the conductive wire 42 therethrough. The slot 226 is dimensioned to slidably fit the conductive wire 62 therein so that the conductive wire 62 may make electrical contact with the second ring terminal 50. The outer diameter of the second insulating tube 220 is dimensioned to slidably fit within the second ring terminal 50.
FIGS. 36-38 show a third insulating tube 230 having a main channel 232, a first channel 234 and a second channel 236. The main channel 232 is dimensioned to receive the conductive tube 20 therein. The first channel 234 is dimensioned to pass the conductive wire 42 therethrough. The second channel 236 is dimensioned to slidably pass the conductive wire 62 therethrough. Since the third insulating tube 230 does not have to accommodate the bent shape of the conductive tube, the main channel 232 is smaller than the main channel 222 of the second insulating tube 220. The bend in the conductive tube thereby enables more uniform spacing between the conductive wires 42, 62, and 62' at the distal end of the proximal connector assembly 190. The outer diameter of the third insulating tube 230 is dimensioned to slidably fit within the main channel 166 of the third insulating spacer 160.
FIGS. 39-41 show a fourth insulating tube 240 having a main channel 242, a first channel 244, a second channel 246 and a slot 248. The main channel 242 is dimensioned to receive the conductive tube 20 therein. The first channel 244 is dimensioned to pass the conductive wire 42 therethrough. The second channel 246 is dimensioned to pass the conductive wire 62 therethrough. The slot 248 is dimensioned to slidably fit the conductive wire 62' therein so that the conductive wire 62' may make electrical contact with the second ring terminal 50'. The outer diameter of the fourth insulating tube 240 is dimensioned to slidably fit within the third ring terminal 50'.
The proximal connector assembly 290, which employs the premolded insulating spacers 140, 150 and 160 and the premolded insulating tubes 210, 220, 230 and 240, is shown in FIGS. 42 and 43. FIG. 42 is a cross-sectional view corresponding to the view shown in FIG. 28. FIG. 43 is a cross-sectional view rotated 90 degrees, with the conductive tube omitted for clarity.
With respect to FIGS. 42 and 43, the preferred method of this alternate embodiment will now be described. First, the conductive tube 20 is welded or otherwise electrically attached to the distal end of the pin terminal 10. Likewise, the conductive wires 42, 62 and 62' are welded or otherwise electrically attached to the first, second and third ring terminals 30, 50 and 50', respectively.
Next, the fourth insulating spacer 170 is slid over the conductive tube 20 and adhesively attached to the distal end of the pin terminal 10. The distal end of the pin terminal 10 is then slidably inserted within the first recess 144 of the first insulating spacer 140. The first protruding portion 34 of the first ring terminal 30 is next slid within the second recess 146 of the first insulating spacer 140. Advantageously, a shoulder 148 (FIG. 20) prevents the first ring terminal 30 from sliding axially too far into the first insulating spacer 140. The fourth insulating spacer 170 creates a precise distance between the first ring terminal 30 and the pin terminal 10.
Next, the first insulating tube 210 is slid over the conductive tube 20 with the conductive wire 42 extending through the slot 214 so that it may make electrical contact with the first ring terminal 30. The protruding portion 154 of the second insulating spacer 150 is then slid over the second protruding portion 36 of the first ring terminal 30. The protruding portion 54 of the second ring terminal 50 is slidably inserted within the recess 158 until it butts up against a shoulder 159 (FIG. 22). Insulating tube 220 is then slidably inserted within the second ring terminal 50 so that the conductive tube 30 and the conductive wire 42 pass therethrough.
The protruding portion 164 of the third insulating spacer 160 is dimensioned to be slidably inserted within the channel 60 of the second ring terminal 50. The third insulating tube 230 is slidably inserted within the third insulating spacer 160 so that the conductive tube 30 and conductive wires 42 and 62 pass therethrough.
The protruding portion 54' of the third ring terminal 50' is slidably inserted within the recess 168 until is butts up against a shoulder 169 (FIG. 24). Insulating tube 240 is then slidably inserted within the third ring terminal 50' so that the conductive tube 30 and the conductive wires 42, 62 and 62' pass therethrough. Epoxy, or other suitable adhesive, may be used between adjacent insulating spacers to bond the assembly together. The assembly is then over-molded in silicone rubber, or other body compatible material.
A side view of the implantable pacemaker lead 320 is shown in FIG. 47. The pacemaker lead 320 includes a multipolar connector assembly 90 having the pin terminal 10 and three ring terminals 30, 50 and 50'. The pacemaker lead 320 further includes the multilumen lead body 100, the connector boot 102, a sensor 330, a ring electrode 332 and a tip electrode 334. The pin terminal 10 is connected to the tip electrode 334. The ring terminal 30 is connected to the ring electrode 332. The second and third ring terminals 50, 50' are connected to a first and second sensor terminal (not shown), respectively. For a complete description of mounting and making electrical connections to the sensor 330 and lead 320, reference is made to copending U.S. patent application Ser. No. 07/716,032, entitled "Pacemaker Lead for Sensing a Physiologic Parameter of the Body," filed 6/14/91, which application is hereby incorporated herein by reference. As is known in the art, sensing cardiac events occurs using the same electrodes as for stimulation (i.e., terminals 332 and 334).
The present invention differs from the prior art in that the present invention does not use multiconductor coils in the proximal connector assembly. In the prior art, multiconductor coils offer the advantages of redundancy and flexibility. However, their overall diameter severely limits the number of conductors one can use in a multipolar proximal connector assembly. The present invention combines straight conductive rods and a stiffer body construction to eliminate any concerns about breaking the electrical connection. Thus, it can be seen that a plurality of conductive rods and ring electrodes may be added to the multipolar proximal connector assembly without increasing the overall diameter. Furthermore, it can be seen that the present invention could be used in a bipolar configuration to simplify lead assembly and may be expandable to a plurality of ring terminals.
Advantageously, each of the insulating spacers 140, 150, 160, 170 and insulating tubes 210, 220, 230 and 240 are premolded using polysulfone, polyether sulfone, or an equivalent class 6 polymer insulating material. The premolded components offer the advantages of rapid assembly, self-positioning of electrodes, precise dimensions, and ease of handling.
In FIGS. 44-46, the proximal connector assembly 300 includes a pin terminal 10, a first ring terminal 30, and four additional identical sensor terminals 50, 50', 50" and 50'". Notice that insulating spacers 310, 310' and 310" are simply a modified insulating spacer 160 with a shorter main body 162 to permit more sensor terminals in the same amount of space.
Thus, it may be apparent that the proximal connector assembly of the present invention consists of a plurality of terminals with straight conductive rods or wires, thus enabling an expandable proximal connector assembly with an extremely slim profile. Furthermore, the preferred embodiment of the present invention includes a plurality of insulating spacers which enable easy and rapid assembly by an operator. By virtue of the shoulders on the insulating spacers, each of the ring terminals is self-positioned with respect to the pin terminal.
Although an exemplary embodiment of the present invention has been shown and described, it will be apparent to those having ordinary skill in the art that a number of changes, modifications, or alterations to the invention as described herein may be made, none of which depart from the spirit of the present invention. All such changes, modifications, and alterations should therefore be seen as within the scope of the present invention.
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An in-line, multipolar proximal connector assembly for an implantable stimulation lead is provided which incorporates at least one sensor. Advantageously, the present invention uses straight conductive rods, or wires, to electrically connect the proximal terminals to a multilumen lead body. The straight conductive rods enable the diameter of the lead assembly to remain small. Additional terminals can easily be added by simply decreasing the spacing between terminals and adding additional conductive rods. In one embodiment, insulating spacers are premolded to include protruding portions which interlock with the ring terminals. Recesses within the insulating spacers are dimensioned to self-position the ring terminals a precise distance from the pin terminal according to precise dimensions defined by the VS-1 (or other) standards. In another embodiment, the terminals are injection molded. While the present invention is directed towards a quadrapolar (four conductors) design, it may be easily adapted to a bipolar, tripolar or multipolar (five conductors or more) design.
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RELATED APPLICATION
[0001] This application is a non-provisional filing of a provisional application, U.S. Ser. No. 61/058,376, filed on Jun. 3, 2008.
FIELD OF THE INVENTION
[0002] The present invention provides a method for treating and/or preventing hematological disorders such as anemia and thrombocytopenia in a subject undergoing treatment for cancer whereby a TPO mimetic peptide compound is administered using a specified dosing regimen. The dosing regimen involves the administration of the TPO mimetic peptide compound within a specified time frame surrounding administration of a chemotherapeutic agent. The dosing regimen also involves monitoring the subject's hematological parameters in order to determine the dose for subsequent treatments.
BACKGROUND OF THE INVENTION
Anemia
[0003] Approximately 75% of cancer subjects receiving chemotherapy develop anemia, and the severity and incidence of anemia increases as the treatment cycles increase. The incidence of anemia was highest in subjects with lung cancer (83.3%) and gynecological malignancies (88.3%). 1 Similar incidence has been reported in an earlier publication, as summarized in Table 1. 2 The severity and incidence of anemia depends on a number of factors, including the type and extent of disease, and type, schedule, intensity, and duration of chemotherapy. For example, the incidence of Grade 2 or higher anemia has been reported to be as high as 71% in non-small cell lung cancer (NSCLC) subjects receiving platinum analogs and gemcitabine combination and the incidence of Grade 3 or higher anemia in this setting has been reported to be 28% (literature reported range from 5 to 28%). 3,4 The incidence of transfusion in this setting has been reported to be approximately 39%. 5
[0000]
TABLE 1
Estimated Incidence and Severity of Chemotherapy-Induced Anemia
Estimated
Grade 1-2
Grade 3-4
New Cases
Anemia
Anemia
Advanced Tumor Type
2005 (US)
(Hb > 8 g/dL)
(Hb < 8 g/dL)
Non-Small-Cell Lung
155,000
up to 85%
up to 34%
Cancer
Small-Cell Lung Cancer
17,000
up to 75%
up to 55%
Breast
213,000
up to 84%
up to 11%
Ovarian
22,000
up to 78%
up to 42%
Lymphomas
63,000
up to 63%
up to 79%
Colorectal
150,000
up to 60%
up to 10%
Head and Neck
29,000
up to 74%
up to 14%
Hb = hemoglobin
[0004] Fatigue is one of the major symptoms associated with chemotherapy induced anemia (CIA). Anemia is well recognized as an adverse prognostic factor for many cancers. Anemia has been reported to be negatively associated with survival in a wide variety of cancers such as lung, head and neck, myeloma, prostate and lymphoma. 6 Prior to the advent of the erythropoiesis stimulating agents (ESAs) (epoetin alfa (Epogen®, Eprex®, Procrit®), epoetin beta (Neo Recormon®), and darbepoetin alfa (Aranesp®)), treatment of CIA was limited to severe cases of anemia (Hb levels of 7-8 g/dL or less) due to dependence on donor red blood cell transfusions, which are a limited resource and are associated with concerns over transmission of infectious diseases and alloimmunization. ESAs have changed the treatment strategy for CIA. Several organizations have developed clinical practice guidelines for the use of ESAs, based upon published studies demonstrating increases in Hb levels, decreases in transfusion requirements, and improvements in quality of life. 7-9 The American Society of Clinical Oncology/American Society of Hematology (ASCO/ASH) guidelines revised in 2007 recommend initiating ESA treatment as hemoglobin (Hb) approaches, or falls below, 10 g/dL. 10 However, current use of ESAs has been associated with possible increased thrombotic vascular events and increased mortality in hemodialysis subjects with cardiac disease, subjects undergoing coronary artery bypass surgery or breast cancer subjects receiving chemotherapy. 11
[0005] An agent that could prevent CIA from occurring at the initiation of chemotherapy treatment without increasing the Hb levels above baseline, and thus eliminating potentially harmful Hb increases known to be associated with ESAs, is highly desirable. Thrombopoietin (TPO) is the primary physiologic regulator of platelet production but additional evidence indicates that TPO has a more pleiotropic range of activities. Pancytopenia has been observed in the absence of TPO or its receptor, c-mpl. 12,13 TPO maintains hematopoietic stem cell viability, 14,15 prevents apoptosis of irradiated bone marrow cells, 16 causes expansion of the stem cell population in combination with other cytokines, 17 enhances in vivo platelet and erythroid recovery following irradiation, 18 and enhances stem cell mobilization into peripheral blood. 19 These multilineage effects support the hypothesis that a TPO agonist could effectively ameliorate CIA by limiting apoptosis in multipotential hematopoietic progenitor cells and by expanding the hematopoietic stem cell population.
Thrombocytopenia
[0006] In addition, a TPO agonist could be efficacious in preventing chemotherapy-induced thrombocytopenia (CIT). Subjects with CIT can have clinically significant bleeding episodes, which are associated with poor clinical outcomes. Such bleeding episodes lead to delay of chemotherapy or dose modification. 20
The TPO Mimetic Peptide Compound
[0007] The TPO mimetic peptide compound is a PEGylated TPO mimetic peptide that has no homology with TPO and the potential to prevent CIA and CIT. See, e.g., U.S. patent application Ser. Nos. 10/918,561, filed Aug. 13, 2004; 11/200,416, filed Aug. 9, 2005; and 11/354,065, filed Feb. 14, 2006, the entire contents of which are incorporated herein by reference. The lack of homology with TPO reduces the potential for generation of anti TPO antibodies. The PEGylation of the peptide leads to a reduced clearance of the compound without loss of potency.
[0008] The TPO mimetic peptide compound is a 29-mer peptide having two identical 14-mers linked by a lysinamide residue as follows:
[0000]
[0000] having a 20,000 MPEG residue covalently linked to each N-terminal isoleucine. The full molecular structure of the TPO mimetic peptide compound is detailed below:
[0000]
[0009] The full chemical name of the TPO mimetic peptide compound is: Methoxypolyethyleneglycol20000-propionyl-L-Isoleucyl-L-Glutamyl-Glycyl-L-Prolyl-L-Threonyl-L-Leucyl-L-Arginyl-L-Glutaminyl-L-2-Naphthylalanyl-L-Leucyl-L-Alanyl-L-Alanyl-L-Arginyl-Sarcosyl-Ne-(methoxypolyethyleneglycol20000-propionyl-L-Isoleucyl-L-Glutamyl-Glycyl-L-Prolyl-L-Threonyl-L-Leucyl-L-Arginyl-L-Glutaminyl-L-2-Naphthylalanyl-L-Leucyl-L-Alanyl-L-Alanyl-L-Arginyl-Sarcosyl-)-Lysinamide.
[0010] The TPO mimetic peptide compound is thus composed of two identical 14 amino acid peptide chains linked by a lysinamide residue and linked on each N-terminal to an approximately 20,000 Dalton molecular weight polyethylene glycol (PEG) chain. The molecular weight of the parent peptide without PEG is 3,295 Daltons and with two PEG chains is approximately 43,295 Daltons. The TPO mimetic peptide compound has an abbreviated molecular structure of (MPEG-Ile-Glu-Gly-Pro-Thr-Leu-Arg-Gln-(2-Nal)-Leu-Ala-Ala-Arg-(Sar))-2-Lys-NH 2 ; where (2-NaI) is β-(2-naphthyl)alanine, (Sar) is sarcosine and MPEG is methoxypoly(ethylene glycol) (MW approximately 20,000 Daltons).
Pre-Clinical Studies
[0011] Pre-clinical studies with the TPO mimetic peptide compound demonstrated an effect on carboplatin induced anemia and carboplatin induced thrombocytopenia in mice. See, e.g., U.S. patent application Ser. Nos. 10/918,561, filed Aug. 13, 2004; 11/200,416, filed Aug. 9, 2005; and 11/354,065, filed Feb. 14, 2006, the entire contents of which are incorporated herein by reference. The data supported a potential myeloprotective and lineage stimulation mechanism.
[0012] One potential concern with the use of growth factors in cancer treatment has been the potential for promotion of tumor growth. The TPO mimetic peptide compound administration alone did not enhance tumor growth and the addition of up to 3 cycles of the TPO mimetic peptide compound treatment to carboplatin therapy had no negative impact on tumor growth delay and in fact led to a small advantage in survival when compared with carboplatin treatment alone. See Example 1. These results are consistent with the literature reports that the thrombopoietin receptor c-mpl has an extremely limited expression in tumor cell lines of the non-myeloid lineage. 22
Clinical Studies in Healthy Volunteers
[0013] The first in human study demonstrated that single intravenous (i.v.) doses of the TPO mimetic peptide compound were safe and generally well tolerated over the dose range tested (0.375 to 3 μg/kg), and there was no evidence of antibody formation against the TPO mimetic peptide compound. See, e.g., U.S. patent application Ser. No. 11/354,065, filed Feb. 14, 2006, the entire contents of which are incorporated herein by reference. A dose dependent, nonlinear increase in mean platelet counts was observed. There were also indications that the TPO mimetic peptide compound increased mean numbers of hematopoietic progenitor cells, although the study was not specifically designed to evaluate this.
Clinical Studies in Cancer Subjects
[0014] Preliminary results from an ongoing study in 46 subjects with cancer (N=12 at 1.5 μg/kg, 12 at 2.25 μg/kg, 10 at 3 μg/kg, and 12 placebo) receiving platinum based chemotherapy suggest that, as compared with placebo, 2.25 and 3 μg/kg doses of the TPO mimetic peptide compound increased platelet count and showed trends for preservation of hemoglobin. See Example 2. These data suggest that the TPO mimetic peptide compound has potential utility in prevention of chemotherapy-induced anemia and thrombocytopenia.
[0015] In subjects with NSCLC receiving a 21-day chemotherapy regimen of gemcitabine and either carboplatin or cisplatin, co-administration of the TPO mimetic peptide compound provides a lower incidence rate of (1) the composite endpoint of Grade 2 or higher anemia, or (2) a ≧2 g/dL drop in hemoglobin on the first day of any chemotherapy cycle (Cycle 2 to 6) relative to baseline (Cycle 1, Day 1), or (3) the use of rescue intervention for anemia (e.g., erythropoiesis stimulating agents [ESAs], red blood cell [RBC] transfusion) as compared to placebo.
[0016] In subjects with NSCLC receiving a 21-day chemotherapy regimen of gemcitabine and either carboplatin or cisplatin, co-administration of the TPO mimetic peptide compound provides a lower incidence rate of (1) the composite endpoint of Grade 2 or higher thrombocytopenia or (2) the use of platelet transfusion as compared to placebo.
[0017] An increased platelet count of >3 times baseline or above 1,000,000 platelets per μL in plasma are considered excessive and provide an increased risk of thrombovascular events in subjects with cancer. Platelets, particularly when activated, are a key factor in a coagulation cascade that results in thrombus formation. A need thus exists for a dosing regimen for the TPO mimetic peptide compound that takes into account the platelet results of each individual patient during each cycle of chemotherapy, and that minimizes or overcomes the risk of thrombovascular events due to excessive platelet increases while treating the patients with the TPO mimetic peptide compound for prevention of CIA and/or CIT.
[0018] The dosing regimen of the invention was designed to increase the safety of the TPO mimetic peptide compound and to increase the efficacy of the TPO mimetic peptide compound while treating and/or preventing CIA and CIT in subjects undergoing chemotherapy.
SUMMARY OF THE INVENTION
[0019] The invention includes a method for treating and/or preventing a hematological disorder in a subject undergoing treatment for cancer, comprising administering the TPO mimetic peptide compound within a specified time frame surrounding said treatment.
[0020] In a preferred embodiment, the TPO mimetic peptide compound is administered within two hours of said administration of said cancer treatment.
[0021] In another preferred embodiment, the TPO mimetic peptide compound is administered within two hours prior to said administration of said cancer treatment.
[0022] The invention also includes a method for treating and/or preventing chemotherapy induced anemia in a subject undergoing treatment for cancer, comprising administering the TPO mimetic peptide compound within a specified time frame surrounding said treatment.
[0023] The invention also includes a method for treating and/or preventing a chemotherapy induced thrombocytopenia in a subject undergoing treatment for cancer, comprising administering the TPO mimetic peptide compound within a specified time frame surrounding said treatment.
[0024] The invention further includes a method for treating and/or preventing a hematological disorder in a subject undergoing treatment for cancer, comprising; determining a hematological parameter of said subject; and administering a dose of said TPO mimetic peptide compound that is dependent upon a value of said hematological parameter.
[0025] The invention is based, in part, on the determination that the maximum effect of the TPO mimetic peptide compound on platelet count occurs on Day 15 after administration of said TPO mimetic peptide compound.
[0026] In a preferred embodiment, platelet count is determined.
[0027] In another preferred embodiment, hemoglobin value is determined.
[0028] The invention further includes adjusting the dose of the TPO mimetic peptide compound, if necessary, based on the subject's hematological values. Adjusting the dose includes reducing the dose or withholding the dose.
[0029] As a means of exemplifying this aspect of the invention, the TPO mimetic peptide compound doses for each cycle of a six cycle treatment regimen are described in Table 2.
Dosing Based on Platelet Response
[0030]
[0000]
TABLE 2
Overview of The TPO Mimetic Peptide Compound
Doses for Cycle 1 to 6
The TPO Mimetic Peptide Compound Dose
Cycle
(μg/kg)
1
2.5
2
3.0 1
3
2.0 to 3.5 2
4
2.0 to 3.5 2
5
2.0 to 3.5 3
6
2.0 to 3.5 2
1 If necessary, the dose will be reduced to 2.5 μg/kg or withheld based on the subject's platelet count on Cycle 1, Day 15 and Cycle 2, Day 1.
2 If necessary, the dose will be titrated or withheld based on the subject's platelet count on Day 15 of the preceding Cycle and Day 1 of this Cycle.
[0031] On Day 1 in Cycle 2, each subject will receive 3.0 μg/kg of the TPO mimetic peptide compound. In the event a subject's Cycle 1 Day 15 platelet count is >700,000 μL, and the platelet count remains >500,000 μL but is <700,000 μL on Day 1 of Cycle 2, the subject will receive a reduced dose of 2.5 μg/kg of the TPO mimetic peptide compound or placebo. If the platelet count is >700,000 μL on Day 1 of Cycle 2, the subject will not be dosed with the TPO mimetic peptide compound in Cycle 2.
[0032] As indicated in the Table 3, on Day 1 of Cycle 3 to 6, the dose of the TPO mimetic peptide compound will be based on the subject's Day 15 platelet count in the previous cycle.
[0033] In Cycle 2 to 5, if a subject's Day 15 platelet count is >700,000 μL, and the platelet count on Day 1 of the next chemotherapy cycle remains >700,000 μL, the subject will not be dosed with the TPO mimetic peptide compound or placebo for that given cycle. Subjects will be dosed again for subsequent cycles if platelets are <700,000 μL on Day 1 of that chemotherapy cycle.
[0034] As a means of exemplifying this aspect of the invention, a detailed dose titration scheme is provided below:
[0000]
TABLE 3
The TPO Mimetic Peptide Compound Dose Titration Scheme for Cycle
3 to 6
Day 15 platelet count of previous
The TPO mimetic peptide
chemotherapy cycle
compound dose (μg/kg)
(Cycle 2 to 5) ×
for next chemotherapy cycle
1000 (/μL)
(Cycle 3 to 6)
≧900 1
2.0
501-899 1
2.5
101-500
3.0
50-100
3.25
<50
3.5
1 If the subject's platelet count on Day 1 of the next chemotherapy cycle is >700,000/μL, the subject will not be dosed with the TPO mimetic peptide compound or placebo for that given cycle. Subjects could be dosed again for subsequent cycles if platelets are <700,000/μL on Day 1 of that chemotherapy cycle. If platelet count continues to be >700,000/μL on Day 1 of two consecutive cycles, the subject will not be given additional doses of the TPO mimetic peptide compound.
Dosing Based on Hemoglobin Value
[0035] According to another embodiment of the invention, and in order to further maximize subject safety, hemoglobin values for each subject will also be evaluated on Day 1 of each chemotherapy cycle to determine if the dose of the TPO mimetic peptide compound should be held. Specifically, if a subject has a hemoglobin value >15 g/dL or has an increase from baseline of ≧2 g/dL on Day 1 of any cycle, the subject will not be dosed with the TPO peptide mimetic compound for that given cycle. The dose of the TPO mimetic peptide compound will not be modified based on hemoglobin values.
[0036] The TPO mimetic peptide compound or placebo will be administered as an IV bolus on Day 1 of each chemotherapy cycle, within 2 hours prior to receiving chemotherapy.
Efficacy Evaluations
[0037] Efficacy evaluations include:
[0038] The difference in incidence rates between the TPO mimetic peptide compound and placebo on (1) the composite endpoint of Grade 2 or higher anemia, or (2) a ≧2 g/dL drop in hemoglobin on the first day of any chemotherapy cycle (Cycle 2 to 6) relative to baseline (Cycle 1, Day 1), or (3) the use of rescue intervention (e.g., ESAs, RBC transfusion) for anemia may be employed for efficacy evaluation.
[0039] The difference between the TPO mimetic peptide compound and placebo on the incidence rates on the composite endpoint of Grade 2 or higher thrombocytopenia or the use of platelet transfusion.
[0040] The difference between the TPO mimetic peptide compound and placebo on the incidence rates of each individual component of the composite endpoints for anemia and thrombocytopenia.
[0041] Hemoglobin, platelet count, use of ESAs, and the use of RBC and platelet transfusions may be the criteria used to evaluate the efficacy endpoints. These parameters may also be part of the safety evaluation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0042] FIG. 1 is a graph showing the individual times to endpoint by group for all animals studied in Example 1.
[0043] FIG. 2 is a graph showing the median tumor growth curves ( FIG. 2 a ) and Kaplan-Meier plots ( FIG. 2 b ) for the animal groups studied in Example 1.
[0044] FIGS. 3 a - 3 c show mean platelet, reticulocyte and hematocrit values, respectively, for Groups 6-9 of animals studied in Example 1 on Days 10, 13, 21, and 24. These data are also included in tabular form in Tables 4a-4-d.
[0045] FIG. 4 is a graph showing Mean Change of Platelet Counts from Baseline (Mean+/−SE) as a result of treatment of subjects with the TPO mimetic peptide compound in accordance with Example 2.
[0046] FIG. 5 is a graph showing Least Squares Mean Change of Hemoglobin Values From Baseline (Mean+/−SE) as a result of treatment of subjects with the TPO mimetic peptide compound in accordance with Example 2.
DETAILED DESCRIPTION OF THE INVENTION
Abbreviations
[0047] The following abbreviations may be used throughout the specification.
[0000] AE(s) Adverse event(s)
ANC Absolute neutrophil count
aPTT Activated partial thromboplastin time
AST Aspartate aminotransferase
BFI Brief Fatigue Inventory
[0048] BFU-E Burst-forming unit-erythroid
CIA Chemotherapy-induced anemia
CIT Chemotherapy-induced thrombocytopenia
D-dimer Fibrin split product, D-dimer
ECG Electrocardiogram
[0049] EC50 Effective concentration inducing 50% maximal effect
ECOG Eastern Cooperative Oncology Group
[0050] ESA Erythropoiesis-stimulating agent
FACT-An Functional Assessment of Cancer Therapy-Anemia
[0051] F1+2 Prothrombin fragment F1+2
FU Follow up
[0052] GIC Global impression of change
Hb Hemoglobin
[0053] huEPO Human erythropoietin
huTPO Human thrombopoietin
IL Interleukin
iv Intravenous
[0054] LLN Lower limit of normal range
LS Least squares
NSCLC Non-small cell lung cancer
PD Pharmacodynamic
[0055] PDGF Platelet derived growth factor
PEG Polyethylene glycol
PF4 Platelet Factor 4
[0056] PFS Progression-free survival
PK Pharmacokinetic
[0057] RBC Red blood cell
RECIST Response Evaluation Criteria in Solid Tumors
[0058] TGF Transforming growth factor
TIBC Total iron binding capacity
TPO Thrombopoietin
[0059] TVE Thrombovascular event
WBC White blood cell
WNL Within normal limits
Definitions
[0060] The following defined terms may be used throughout the specification.
[0061] As used herein, the terms “comprising”, “containing”, “having” and “including” are used in their open, non-limiting sense.
[0062] “Anemia” is a deficiency of red blood cells (RBCs) and/or hemoglobin. This results in a reduced ability of blood to transfer oxygen to the tissues, causing tissue hypoxia. Since all human cells depend on oxygen for survival, varying degrees of anemia can have a wide range of clinical consequences. Hemoglobin (the oxygen-carrying protein in the red blood cells) has to be present to ensure adequate oxygenation of all body tissues and organs.
[0063] “Grade of anemia” is the severity of anemia on a scale from 0 to 5 as determined in accordance with criteria specified in Attachment 1.
[0064] “Grade of thrombocytopenia” is the severity of thrombocytopenia on a scale from 0 to 5 as determined in accordance with criteria specified in Attachment 1.
[0065] “Hematocrit” (Ht or HCT) and packed cell volume (PCV) are measures of the proportion of blood volume that is occupied by red blood cells. It is normally 45±7 (38-52%) for males and 42±5 (37-47%) for females.
[0066] “Hemoglobin”, also spelled haemoglobin and abbreviated Hb, is the iron-containing oxygen-transport metalloprotein in the red blood cells of the blood.
[0067] “Hemoglobin value” is the amount of hemoglobin in blood in g/dL.
[0068] Mean platelet volume” (MPV) is a measurement of the average size of platelets found in blood and is typically included in blood tests. Since the average platelet size is larger when the body is producing increased numbers of platelets, MPV test results can be used to make inferences about platelet production in bone marrow.
[0069] “Myelosuppressive agent” is an agent, which causes a condition in which bone marrow activity is decreased, resulting in fewer red blood cells, white blood cells, and platelets.
[0070] “Nadir” is the lowest blood count for a given patient in a given period of time (i.e., a patient's ANC Nadir or absolute neutrophil count). For example, patients undergoing chemotherapy will exhibit an ANC Nadir a week after starting therapy due to bone marrow suppression.
[0071] “Neutropenia” is a hematological disorder characterized by an abnormally low number of neutrophils (a type of white blood cell). Neutrophils usually make up 50-70% of circulating white blood cells and serve as the primary defense against infections by destroying bacteria in the blood. Hence, patients with neutropenia are more susceptible to bacterial infections and without prompt medical attention, the condition may become life-threatening.
[0072] “Neutrophil count” otherwise know as “absolute neutrophil count” (ANC) is a measure of the number of neutrophil granulocytes (also known as polymorphonuclear cells, PMN's, polys, granulocytes, segmented neutrophils or segs) present in the blood. Neutrophils are a type of white blood cell that fights against infection. The ANC is calculated from measurements of the total number of white blood cells (WBC) and the numbers of neutrophils and bands, which form a subset of the total number of white blood cells. A normal ANC is above 1,500. An ANC less than 500 is defined as neutropenia and significantly increases the risk of infection. Neutropenia is the condition of a low ANC, and the most common condition where an ANC would be measured is in the setting of chemotherapy for cancer.
[0073] “Pancytopenia” is a medical condition in which there is a reduction in the number of red and white blood cells, as well as platelets. Pancytopenia is generally due to diseases affecting the bone marrow. Chemotherapy for malignancies may also cause pancytopenia, if the drug or drugs used cause bone marrow suppression.
[0074] “Platelet count” is the calculated number of platelets in a volume of blood, usually expressed as platelets per cubic millimeter (cmm) of whole blood. Normal platelet counts are in the range of about 150,000 to 450,000 per microliter (or 150−450×10 9 per liter). These values many vary slightly between different laboratories.
[0075] “Red blood cells” otherwise know as “erythrocytes” are the most common type of blood cell and the principal means of delivering oxygen from the lungs to body tissues via the blood.
[0076] “Thrombocytopenia” is the presence of relatively few platelets in blood. Generally speaking a normal platelet count ranges from about 150,000 and 450,000 per mm 3 . These limits, however, are determined by the 2.5 th lower and upper percentile, and a deviation does not necessarily imply any form of disease. The number of platelets in a blood sample also decreases rather quickly with time and a low platelet count may be caused by a delay between sampling and analysis.
[0077] “White blood cell count” is the number of white blood cells (WBCs) in the blood. The WBC is usually measured as part of the CBC (complete blood count). White blood cells are the infection-fighting cells in the blood. There are different types of white blood cells, including neutrophils (polymorphonuclear leukocytes; PMNs), band cells (slightly immature neutrophils), T-type lymphocytes (T cells), B-type lymphocytes (B cells), monocytes, eosinophils, and basophils. All the types of white blood cells are reflected in the white blood cell count. The normal range for the white blood cell count varies between laboratories but is usually between 4,300 and 10,800 cells per cubic millimeter of blood. This can also be referred to as the leukocyte count and can be expressed in international units as 4.3−10.8×10 9 cells per liter.
Non-Clinical Pharmacology
[0078] The TPO mimetic peptide compound has an estimated EC 50 of approximately 5 pM (0.2 ng/mL) in a human TPO (huTPO) receptor assay in vitro and stimulates megakaryocyte lineage specific growth and differentiation in vivo. A single i.v. dose of the TPO mimetic peptide compound (30 to 300 μg/kg) resulted in an increased platelet count in the rat that was maximal after 6 days and returned to baseline after 12 days. Additionally, a single dose of the TPO mimetic peptide compound displayed a myeloprotective effect in murine models of CIT by reducing the severity and duration of CIT in a dose-dependent manner (minimum effective dose 100 μg/kg) on Day 12.
[0079] Administration of the TPO mimetic peptide compound 1 hour after chemotherapy was more effective than dosing after 24 or 96 hours. In these studies, the TPO mimetic peptide compound also prevented a chemotherapy-induced reduction in Hb, hematocrit and RBC count, supporting a pluripotent protective effect on the megakaryocyte and erythroid lineages. Furthermore, following carboplatin treatment, the anti-anemic effect of the TPO mimetic peptide compound was observed at doses as low as 30 μg/kg. Additional studies also demonstrated that inhibition of chemotherapy-induced anemia and thombocytopenia by the TPO mimetic peptide compound correlated with a marked reduction in fibrinogen-positive microangiopathic lesions in small blood vessels in the brain. These histological findings suggest that prevention of the development of the microangiopathic events with the TPO mimetic peptide compound may be due to decreased platelet deposition as well as reduced microhemorrhage, which may contribute to prevention of chemotherapy-induced thrombocytopenia and anemia.
Example 1
[0080] Administration of the TPO Mimetic Peptide Compound One Hour After Administration of Carboplatin. Effect on activity and toxicity of carboplatin against HT-29 human colon carcinoma xenografts established in athymic nude mice.
[0081] Five groups (n=10) of female athymic nude mice (Harlan) bearing established (˜100 mm 3 ) HT-29 human colon carcinomas on Day 1. Groups 6-9 (n=20) were included for blood sampling and received the same treatment as Groups 1-4, respectively. Treatment effects on the growth of tumors were evaluated by tumor growth delay (TGD), which is the difference between median time to endpoint (TTE) tumor size in a treatment group compared to a control group. The effect of these treatments on platelet and erythrocyte precursors was determined from CBC analysis and reticulocyte counts of blood samples taken on Days 10, 13, 21 and 24.
[0000]
TABLE 4
% Tumor
Median TTE
Tumor Burden
Group #
Treatment
Growth Delay
in days
Median
?
Group 1, 6
Untreated tumor
—
24.8
—
—
controls
Group 2, 7
60 mg/kg
92
47.6
600(1)
−3/1%,
carboplatin,
Day 17
administered i.p.
Days 1, 2, 12 and
13
Group 3, 8
0.2 mg/kg TPO
33
32.9
—
—
mimetic peptide
compound,
administered i.v.
Days 2, 13 and
Days 2, 13 and
23, administered
i.v. 1 hour after
carboplatin
dosing
Group 4, 9
Combination of
119
54.2
—
−5.1%, Day
carboplatin and
17
TPO mimetic
peptide
compound
administered as
above (Days 2,
13)
Group 5
Combination of
150
62
877(?)
−3.5%, Day
carboplatin and
17
TPO mimetic
peptide
compound
administered as
above (Days 2,
13 and 23)
Tumor Implantation
[0082] Xenografts were initiated from HT-29 human colon carcinoma xenografts maintained in athymic nude mice. HT-29 tumor fragments (1 mm 3 ) were implanted subcutaneously into the right flank of each test mouse, and tumor growth was monitored. On Day 1 of the study, the animals were pair-matched into five groups (Groups 1-5) for evaluation of efficacy and four groups for sampling (Groups 6-9). Groups 1-5 each consisted of ten animals with tumor sizes ranging from 75-126 mm 3 and group mean tumor sizes of 99 mm 3 . Groups 6-9 each consisted of twenty animals with tumor sizes ranging from 40-221 mm 3 and group mean tumor sizes of 84 mm 3 . Tumor weight was estimated with the assumption that 1 mg is equivalent to 1 mm 3 of tumor volume. Volume was calculated using the formula:
[0000]
Tumor
Volume
(
mm
3
)
=
w
2
×
l
2
[0000] where w=width and l=length in mm of an HT-29 tumor.
Therapeutic Agent
[0083] The TPO mimetic peptide compound was provided in nine tubes each containing 20 μL of a 10 mg/mL stock solution and stored at −20° C. Dosing solutions of the TPO mimetic peptide compound (20 μg/mL) were prepared fresh daily by transferring a 20 μL aliquot of stock solution under sterile conditions to 10 mL sterile saline and tumbling gently to mix. These mixtures were not allowed to foam and were not filter sterilized. Any residual dosing solutions and unused aliquots were stored at −20° C.
[0084] Carboplatin (Sigma, Lot #034K0868) in powder form (three vials each containing 250 mg) was stored at room temperature. Carboplatin dosing solutions (6 mg/mL) were prepared fresh on day of dosing in sterile phosphate buffered saline (PBS), and were filter sterilized prior to administration.
Treatment
[0085] Table 5 summarizes the treatment plan for this study. Group 1 mice (n=10) were untreated tumor growth controls. Group 2 mice (n=10) received 60 mg/kg carboplatin administered intraperitoneally (i.p.) on Days 1, 2, 12, and 13. Group 3 mice (n=10) received 0.2 mg/kg of the TPO mimetic peptide compound administered intravenously (i.v.) via tail vein on Days 2 and 13. Groups 4 and 5 received the combination of carboplatin (60 mg/kg i.p. on Days 1, 2, 12, and 13) and 0.2 mg/kg of the TPO mimetic peptide compound on Days 2, 13 and Days 2, 13, 23, respectively, administered intravenously (i.v.) one hour after carboplatin dosing. Groups 6-9 (n=20 each) were included for blood sampling and received the same treatments as Groups 1-4, respectively. For all groups, each dose of drug was given in a volume of 0.2 mL per 20 g of body weight (10 mL/kg), and was scaled to the body weight of each animal.
Endpoint
[0086] Tumors were measured twice each week using calipers. Each animal was euthanized when its tumor reached the predetermined endpoint size of 1000 mm 3 , or on the final day of the study (Day 62), whichever came first. The time to endpoint (TTE) for each mouse was calculated from the following equation:
[0000]
T
T
E
(
days
)
=
log
10
(
endpoint
volume
,
mm
3
)
-
b
m
[0000] where b is the intercept and m is the slope of the line obtained by linear regression of a log-transformed tumor growth data set. The data set was comprised of the first observation that exceeded the study endpoint volume and the three consecutive observations that immediately preceded the attainment of the endpoint volume. Animals that did not reach the endpoint were assigned a TTE value equal to the last day of the study, animals classified as TR (treatment related) deaths were assigned a TTE value equal to the day of death, and animals classified as NTR (non-treatment related) deaths were excluded from analysis.
[0087] Treatment outcome was determined from tumor growth delay (TGD), which is defined as the increase in the median time to endpoint (TTE) in a treatment group compared to the control group:
[0000]
TGD=T−C,
[0000] expressed in days, or as a percentage of the median TTE of the control group:
[0000]
%
T
G
D
=
T
-
C
C
×
100
[0000] where:
T=median TTE for a treatment group, C=median TTE for the control group (Group 1)
[0090] Treatment may cause partial regression (PR) or complete regression (CR) of the tumor in an animal. In a PR response, the tumor volume is 50% or less of its Day 1 volume for three consecutive measurements during the course of the study, and equal to or greater than 13.5 mm 3 for one or more of these three measurements. In a CR response, the tumor volume is less than 13.5 mm 3 for three consecutive measurements during the course of the study. An animal with a CR response at the termination of a study is additionally classified as a long-term tumor-free survivor (LTTFS). Tumor regressions were monitored and recorded.
Sampling
[0091] In Groups 6-9, five mice per group were euthanized by terminal cardiac puncture under CO 2 anesthesia on Days 10, 13, 21 and 24, and gross necropsies were performed. Blood was collected into EDTA tubes, and complete blood counts (CBC) with differential were determined using a Cell-Dyn® 3700 System (Abbott Diagnostics) for automated hematology analyses. Reticulocyte values were determined. In addition, for Groups 1-5, five animals per group were euthanized at or just after endpoint by terminal cardiac puncture under CO 2 anesthesia, and gross necropsies were performed. Blood samples were collected into EDTA tubes, and CBC with differential and reticulocyte values were performed as previously described. All other animals in Groups 1-5 were euthanized at endpoint without sampling.
Toxicity
[0092] Animals were weighed daily for the first five days of the study and then twice weekly. The mice were observed frequently for overt signs of any adverse, treatment-related side effects. Acceptable toxicity for cancer drugs in mice is defined by the NCI as a group mean body-weight loss of less than 20% during the test, and not more than one toxic death among ten treated animals.
Statistical and Graphical Analyses
[0093] The Logrank test was used to analyze the significance of the differences between the TTE values of treated and control groups. The Fisher's Exact test was employed to analyze the significance of differences in the number of 62-day survivors in Group 5 treated with the combination of carboplatin and the TPO mimetic peptide compound and Group 2 treated with carboplatin alone. For both tests, two-tailed statistical analyses were conducted at significance level P=0.05, with results deemed significant at 0.01≦P≦0.05, and highly significant at P<0.01.
[0094] Median tumor growth curves show group median tumor volumes as a function of time. When an animal exited the study due to tumor size, the final tumor volume recorded for the animal was included with the data used to calculate the median volume at subsequent time points. Kaplan-Meier plots were constructed to show the percentage of animals remaining in the study as a function of time. These plots used the same data set as the Logrank test. Mean CBC values were plotted in bar graph form, with error bars showing one standard deviation of the mean. Prism (GraphPad) for Windows 3.03 was used for all graphic presentations and statistical analyses.
Results
[0095] The individual times to endpoint by group for all animals in the study are shown in FIG. 1 . FIG. 2 shows the median tumor growth curves ( FIG. 2 a ) and Kaplan-Meier plots ( FIG. 2 b ) for the groups in the study. FIGS. 3 a - 3 c show mean platelet, reticulocyte and hematocrit values, respectively, for Groups 6-9 on Days 10, 13, 21, and 24.
Efficacy
HT-29 Tumor Growth in Control Mice (Group 1)
[0096] The tumors of all untreated Group 1 mice (n=10) grew progressively to the 1000 mm 3 endpoint tumor volume with a median TTE of 24.8 days. FIG. 1 shows the scatter plot of TTE values for this group, and the median tumor growth curve is included in FIG. 2 a.
Response of HT-29 Xenografts to Carboplatin (Group 2)
[0097] In Group 2 mice (n=10) treated with carboplatin (60 mg/kg i.p. Days 1, 2, 12, 13), nine tumors grew to the endpoint tumor volume and one animal remained in the study on Day 62 with a tumor volume of 600 mm 3 . No regression responses were recorded. The median TTE was 47.6 days, and corresponded to a statistically significant 22.8-day (92%) TGD (P=0.001). The median tumor growth curve in FIG. 2 a illustrates the delay in tumor growth in Group 2 mice compared to untreated Group 1 controls.
Response of HT-29 Xenografts to the TPO Mimetic Peptide Compound
[0098] The tumors of all Group 3 mice (n=10) treated with the TPO mimetic peptide compound (0.2 mg/kg i.v. Days 2, 13) grew progressively to the endpoint tumor volume. The Group 3 median TTE was 32.9 days and corresponded to a statistically non-significant 8.1-day (33%) TGD relative to Group 1 controls. The Group 3 median tumor growth curve in FIG. 2 a is shifted slightly to the right of the curve of untreated Group 1 controls.
Response of HT-29 Xenografts to the Combination of Carboplatin and the TPO Mimetic Peptide Compound (Groups 4 and 5)
[0099] The tumors of all Group 4 mice (n=10) treated with the combination of carboplatin (60 mg/kg i.p. Days 1, 2, 12, 13) and two cycles of the TPO mimetic peptide compound (0.2 mg/kg i.v. Days 2, 13) grew progressively to the endpoint tumor volume. The median TTE was 54.2 days, and corresponded to a statistically significant 29.4-day (119%) TGD relative to untreated Group 1 controls (P<0.001). However, TTE values in this group were not significantly different from those of Group 2 treated with carboplatin monotherapy. The Group 4 median tumor growth is very similar to the curve of Group 2 treated with carboplatin monotherapy ( FIG. 2 a ).
[0100] In Group 5 mice (n=10) treated with the combination of carboplatin (60 mg/kg i.p. Days 1, 2, 12, 13) and three cycles of the TPO mimetic peptide compound (0.2 mg/kg i.v. Days 2, 13, 23), four tumors grew to the 1000 mm 3 endpoint tumor volume and six animals remained in the study on Day 62 with a median tumor volume of 877 mm 3 (see Table 4). No regression responses were recorded. The median TTE was 62.0 days and corresponded to a statistically significant 37.2-day (150%) TGD relative to untreated Group 1 controls (P<0.001). When compared to Group 2 treated with carboplatin monotherapy, TGD in Group 5 approached statistical significance (P=0.067). The increase in number of Group 5 62-day survivors (n=6) also approached statistical significance when compared to the number of 62-day survivors (n=1) in Group 2 carboplatin monotherapy-treated mice by Fisher's Exact analysis (P=0.057). The median tumor growth curve for Group 5 is shifted slightly to the right of the curves for Groups 2 and 4. ( FIG. 2 a )
CBC Analyses
[0101] Mean values for platelets (PLT), reticulocytes (RET), and hematocrit (HCT) for Groups 6-9 are presented graphically in FIGS. 3 a - 3 c.
Platelets
[0102] FIG. 3 a shows the mean platelet counts for Groups 6-9 on Days 10, 13, 21, and 23. Mean values were within the reference range established for female Harlan nude mice for all groups at all four time points. When compared to untreated Group 6 controls, carboplatin-treated mice (Group 7) had lower mean platelet counts at all time points and treatment with the TPO mimetic peptide compound (Group 8) resulted in higher mean platelet counts at all four time points.
[0103] Mice treated with the combination of carboplatin and the TPO mimetic peptide compound (Group 9) had mean platelet counts that were similar to those in the untreated control group. At each time point, mean platelet values in the combination treatment group (Group 9) were higher than those in Group 7 treated with carboplatin alone, with highest mean platelet count in Group 9 observed on Day 10.
Reticulocytes
[0104] FIG. 3 b shows mean reticulocyte values for Groups 6-9 on Days 10, 13, 21, and 23. Untreated controls (Group 6) and the TPO mimetic peptide compound-treated animals (Group 8) had mean reticulocyte values that remained relatively consistent at all time points, although mean values in Group 8 were slightly higher than in Group 6 controls. In carboplatin-treated animals (Group 7), mean reticulocyte values were negligible on Day 10 (near the expected nadir), higher than in control mice on Day 13, and then low on Day 21 after the second cycle of treatment. The combination treatment group (Group 9) followed a similar pattern, but the mean Day 10, 13 and 21 reticulocyte values in Group 9 were both higher than in Group 7 treated with carboplatin alone.
Hematocrit
[0105] FIG. 3 c shows mean hematocrit (HCT) values for Groups 6-9 on Days 10, 13, 21, and 23. Mean HCT values were similar for untreated mice (Group 6) and the TPO mimetic peptide compound-treated mice (Group 8) at all time points. Animals treated with carboplatin only (Group 7) and the combination of carboplatin and the TPO mimetic peptide compound (Group 9) had lower mean HCT values than controls, with Group 7 mean HCT values being slightly lower than those of Group 9 on Days 13, 21, and 23.
Side Effects
[0106] Animals were monitored for adverse treatment-related effects by frequent observation and body-weight (BW) measurements (data not shown). The TPO mimetic peptide compound monotherapy (Group 3) was well tolerated, with no treatment-related (TR) deaths and no mean BW losses. Clinical observations were remarkable for large spleens in ⅖ necropsied Group 3 animals. The combination of the TPO mimetic peptide compound with carboplatin (Groups 4 and 5) resulted in similar BW mean losses compared to treatment with carboplatin alone (Group 2).
[0107] Clinical observations in Groups 2, 4 and 5 were remarkable for several mice with dark or mottled spleens upon necropsy. No TR mortality occurred in any group.
[0108] In summary, the TPO mimetic peptide compound did not enhance tumor growth. The addition of up to 3 cycles of the TPO mimetic peptide compound had no negative impact on tumor delay and in fact led to a small increase in survival when compared to carboplatin treatment alone.
Human Studies
[0109] The TPO mimetic peptide compound has been investigated in 2 human studies.
Single Dose Study in Healthy Subjects
[0110] Single i.v. doses of the TPO mimetic peptide compound up to and including 3 μg/kg were well-tolerated in healthy male subjects, with no apparent drug-related effects on adverse events, or cardiovascular or laboratory safety parameters (excluding platelet counts). Antibodies against the TPO mimetic peptide compound were not apparent in any post dose samples.
[0111] Single i.v. administration of the TPO mimetic peptide compound dose-dependently increased mean platelet count in healthy male subjects. Mean megakaryocyte ploidy was increased compared with placebo following doses of 1.5 μg/kg and above, and the mean number of CD62P+ platelets appeared to increase following administration of the 2 highest doses of the TPO mimetic peptide compound (although this was not reflected in other measures of platelet activation). Mean numbers of hematopoietic progenitor cells (burst-forming-unit erythroid [BFU-E] and peripheral CD34+ cells) increased compared with placebo following the highest dose of the TPO mimetic peptide compound.
[0112] The median t max of the TPO mimetic peptide compound ranged between 0.09 to 2 hours following single i.v. administration. In general, subjects showed more than 1 maximum in the profile, with a second maximum generally around 4 to 8 hours post dose. The mean terminal half-life was approximately 36 hours at 3 μg/kg: for most subjects there was limited data available in the terminal phase, therefore the half-life was not well defined. However, the elimination phase appeared consistent across the dose range. C max increased approximately dose proportionally. For AUC, no apparent dose proportionality could be determined across the 1.5- to 3-μg/kg dose range.
Example 2
Multiple Dose Study in Cancer Subjects
[0113] 46 subjects with cancer receiving platinum-based therapies were enrolled into 3 cohorts (N=16 in Cohort 1, 14 in Cohort 2, and 16 in Cohort 3). The subjects received the TPO mimetic peptide compound or placebo within 2 hours prior to the platinum-based chemotherapy on Day 1 of the first 2 cycles with a 21-day interval between each cycle. In addition to the Day 1 administration, gemcitabine administration was permitted on Day 8 of each cycle. Other chemotherapy medications were limited to dosing on Day 1 of each cycle only. Subjects were followed up for a total of 4 cycles of chemotherapy. Chemotherapy regimen continued beyond the first 4 cycles as per standard of care therapy. In the first cohort, 12 subjects received 1.5 μg/kg the TPO mimetic peptide compound and 4 subjects received placebo. In the second cohort 10 subjects received 3.0 μg/kg the TPO mimetic peptide compound and 4 subjects received placebo. In the third cohort, 12 subjects received 2.25 μg/kg the TPO mimetic peptide compound and 4 subjects received placebo. One of the dose escalation stopping criteria (platelet elevations of >3 times the baseline in 2 subjects) were met at 3.0 μg/kg dose. Therefore, a third cohort at a lower dose (2.25 μg/kg) was added to collect additional safety, tolerability, PD, and PK data. Preliminary safety, PK and PD data from these 3 cohorts at 1.5, 2.25, and 3.0 μg/kg are summarized below.
[0114] The distribution of tumor types and chemotherapy is detailed in Table 5.
[0000]
TABLE 5
Tumor Type and Chemotherapy
The TPO mimetic peptide compound
Placebo
1.5 μg/kg
2.25 μg/kg
3.0 μg/kg
N = 12
(N = 12)
(N = 12)
(N = 10)
Tumor type
NSCLC (7)
Head and Neck
Gastric (2)
NSCLC (2)
(N)
SCLC (1)
(1)
NSCLC (3)
Ovary (4)
Ovary (2)
NSCLC (1)
Pancreatic (1)
Cervix (1)
Other (2)
Ovary (3)
SCLC (2)
Other (2)
Pancreatic (2)
Other (4)
Colorectal (1)
Cervix (1)
Bladder (1)
Other (3)
Platinum therapy
Carboplatin (8):
Carboplatin (6):
Carboplatin (9):
Carboplatin (7):
(N):
626 (430-909)
537 (379-800)
513 (339-700)
516 (300-730) mg
Mean dose (range)
mg
mg
Cisplatin (3):
Cisplatin (2):
Cisplatin (4):
Cisplatin (6):
136 (100-168)
103 (80-125) mg
136 (116-148)
116 (50-140) mg
Oxaliplatin (1):
Oxaliplatin (1):
150 mg
220 mg
Chemotherapy
Gemcitabine
Gemcitabine (10):
Gemcitabine (4):
Gemcitabine (5):
(N):
(8):
1624 (497-2044)
1888 (1520-2625)
1577 (1000-1980)
Mean dose (range)
2002 (1200-2339)
mg
Epirubicin (1): 100 mg
mg
Paclitaxel (4):
Paclitaxel (1): 277 mg
Paclitaxel (6):
Paclitaxel (4):
325 (290-400)
5-FU (1): 5782 mg
286 (243-324)
294 (270-330) mg
Irinotecan (1): 270 mg
[0115] Pharmacokinetics at 1.5 μg/kg dose was similar to those in healthy subjects. Placebo subjects from all cohorts were pooled.
[0116] At the 1.5 μg/kg dose there was no apparent difference in the platelets as compared to the placebo subjects. However, at the 2.25 and 3 μg/kg dose, platelet nadir and peak platelet counts were approximately 2-fold higher relative to placebo ( FIG. 4 , Table 6 and 7). Mean platelet nadir was observed on Day 10 for the 2.25 and 3 μg/kg dose groups, but for the placebo and 1.5 μg/kg dose, platelets continued to decline up to Day 15. Mean peak platelets were observed on Day 15 for the 3.0 μg/kg dose but for the placebo, 2.25 and 1.5 μg/kg doses, peak platelets were observed on Day 21.
[0117] Two subjects at the 3.0 μg/kg dose had a transient platelet increase of more than 3 times the baseline in the first cycle (stopping criteria for further dose escalation) but no subjects in the 1.5 and 2.25 μg/kg dose group met the stopping criteria.
[0118] The platelet elevations were attenuated in the second cycle and remained below 3 times the baseline in all subjects. These results at the 2.25 and 3 μg/kg dose, indicate a reduction in chemotherapy-induced decline in platelets and faster recovery relative to placebo, suggesting potential for the TPO mimetic peptide compound in prevention of CIT ( FIG. 4 , Table 6 and 7).
[0119] A total of 7 subjects were excluded from the preliminary statistical analysis of Day 42 platelet count data and 9 subjects were excluded from the preliminary statistical analysis of Day 42 hemoglobin data due to either incorrect randomization, platelet transfusion, not administered the 2 nd dose of study medication, or lost to follow-up.
[0000]
TABLE 6
Minimum Platelet Counts
GMR
95%
Geometric
(Active/
Confidence
Cycle
Treatment Group
N
Mean
Placebo)
Interval
Cycle 1
Placebo
12
94.13
1.5 μg/kg
9
47.01
0.5
(0.2, 1.2)
2.25 μg/kg
11
213.46
2.3
(1.0, 5.2)
3.0 μg/kg
9
191.17
2.0
(0.8, 5.1)
Cycle 2
Placebo
12
78.67
1.5 μg/kg
8
75.10
1.0
(0.6, 1.6)
2.25 μg/kg
10
175.08
2.2
(1.4, 3.7)
3.0 μg/kg
9
170.16
2.2
(1.3, 3.7)
Across
Placebo
12
60.96
1.5 μg/kg
9
33.99
0.6
(0.3, 1.2)
2.25 μg/kg
11
163.71
2.7
(1.3, 5.4)
3.0 μg/kg
9
121.61
2.0
(0.9, 4.3)
[0000]
TABLE 7
Maximum Platelet Counts
GMR
95%
Geometric
(Active/
Confidence
Cycle
Treatment Group
N
Mean
Placebo)
Interval
Cycle 1
Placebo
12
301.84
1.5 μg/kg
9
331.25
1.1
(0.8, 1.5)
2.25 μg/kg
11
557.78
1.8
(1.4, 2.5)
3.0 μg/kg
9
641.56
2.1
(1.5, 3.0)
Cycle 2
Placebo
12
289.10
1.5 μg/kg
8
290.55
1.0
(0.7, 1.5)
2.25 μg/kg
10
397.37
1.4
(0.9, 2.0)
3.0 μg/kg
9
401.20
1.4
(0.9, 2.1)
Across
Placebo
12
356.50
1.5 μg/kg
9
371.53
1.0
(0.8, 1.4)
2.25 μg/kg
11
570.39
1.6
(1.2, 2.1)
3.0 μg/kg
9
633.09
1.8
(1.3, 2.4)
[0120] Preliminary evaluation of the change in hemoglobin levels from baseline to the end of Cycle 2 (Day 42) and beyond also suggests a dose-related trend for preservation of hemoglobin ( FIG. 5 , Table 8).
[0000]
TABLE 8
Statistical Analysis of the TPO mimetic peptide compound
Change From Baseline in Hemoglobin at Days 42, 63, and 84
95%
LS Mean
Reference
Diff of LS
Confidence
Day
Treatment Group
N
(SE)
Group
Mean (SE)
Interval
Day 42
Placebo
12
−2.17 (0.39)
1.5 μg/kg
7
−1.63 (0.50)
Placebo
0.54 (0.63)
(−0.8, 1.8)
2.25 μg/kg
10
−1.60 (0.42)
Placebo
0.57 (0.57)
(−0.6, 1.7)
3.0 μg/kg
8
−1.16 (0.47)
Placebo
1.00 (0.61)
(−0.2, 2.2)
Day 63
Placebo
9
−2.23 (0.57)
1.5 μg/kg
6
−2.98 (0.70)
Placebo
−0.75 (0.90)
(−2.6, 1.1)
2.25 μg/kg
8
−1.55 (0.61)
Placebo
0.68 (0.83)
(−1.0, 2.4)
3.0 μg/kg
8
−1.44 (0.61)
Placebo
0.79 (0.83)
(−0.9, 2.5)
Day 84
Placebo
8
−1.93 (0.48)
1.5 μg/kg
6
−1.88 (0.55)
Placebo
0.05 (0.73)
(−1.5, 1.6)
2.25 μg/kg
5
−1.56 (0.61)
Placebo
0.37 (0.77)
(−1.2, 2.0)
3.0 μg/kg
5
−0.36 (0.61)
Placebo
1.57 (0.77)
(−0.0, 3.2)
[0121] Although adverse events were observed (see Table 9), the adverse events did not appear to be related to increasing doses of the TPO mimetic peptide compound; did not appear to be different from placebo group; and appeared to be those commonly reported with the chemotherapy utilized in the study.
[0000]
TABLE 9
Treatment-Emergent Adverse Events by Body System and Preferred Term
Body System or Organ Class
Placebo
1.5 ug/kg
2.25 ug/kg
3.0 ug/kg
Dictionary-derived Term
(N = 12) N
(N = 12) n
(N = 12) n
(N = 10) n
Total no. subjects WITH ADVERSE EVENTS
11
12
10
9
Gastrointestinal disorders
9
7
7
6
Nausea
8
6
2
2
Vomiting
8
2
6
2
Constipation
3
3
2
4
Abdominal pain
0
2
1
2
Diarrhea
1
2
1
1
Dyspepsia
2
0
0
0
Stomatitis
0
2
0
0
Eructation
0
0
1
0
Hemorrhoids
0
1
0
0
Blood and lymphatic system disorders
8
8
6
3
Neutropenia
6
3
4
3
Anemia
1
7
2
1
Leukopenia
3
2
3
2
Thrombocytopenia
5
3
0
2
Lymphopenia
0
2
0
0
Febrile neutropenia
0
0
1
0
Leukocytosis
0
0
0
1
Thrombocythaemia
0
1
0
0
General disorders and administration site
7
7
3
6
conditions
Fatigue
4
5
1
4
Pyrexia
2
1
3
2
Pain
0
3
0
0
Oedema
0
0
1
1
Chills
0
0
1
0
General physical health deterioration
0
0
1
0
Mucosal inflammation
1
0
0
0
Oedema peripheral
0
1
0
0
Metabolism and nutrition disorders
5
5
2
3
Anorexia
5
5
0
2
Dehydration
0
0
1
1
Hyponatraemia
0
0
2
0
Diabetes mellitus non-insulin-dependent
0
1
0
0
Hypoalbuminaemia
0
0
1
0
Hypocalcaemia
0
1
0
0
Hypokalaemia
0
0
1
0
Hypomagnesaemia
0
0
1
0
Hypophosphataemia
0
1
0
0
Skin and subcutaneous tissue disorders
4
4
3
3
Alopecia
2
2
3
2
Rash
1
2
0
0
Dermatitis acneiform
1
0
0
0
Dry skin
0
0
0
1
Nervous system disorders
4
3
3
2
Headache
1
1
1
1
Dizziness
1
0
2
0
Paraesthesia
2
0
0
1
Peripheral motor neuropathy
1
1
0
0
Neuropathy peripheral
0
1
0
0
Peripheral sensory neuropathy
1
0
0
0
Investigations
1
3
2
4
Blood creatinine increased
0
1
1
1
Haematocrit decreased
0
0
1
1
Weight decreased
1
1
0
0
Alanine aminotransferase increased
0
0
0
1
Aspartate aminotransferase increased
0
0
0
1
C-reactive protein increased
0
0
0
1
Platelet count decreased
0
1
0
0
Respiratory, thoracic and mediastinal
2
2
3
1
disorders
Cough
1
0
2
0
Dyspnoea
0
1
1
0
Epistaxis
1
0
0
1
Hiccups
0
1
1
0
Respiratory failure
0
1
0
0
Infections and infestations
1
4
0
0
Infection
0
2
0
0
Folliculitis
0
1
0
0
Gastrointestinal infection
1
0
0
0
Lung abscess
0
1
0
0
Respiratory tract infection
0
1
0
0
Musculoskeletal and connective tissue
1
0
1
2
disorders
Arthralgia
1
0
0
1
Pain in extremity
0
0
1
1
Psychiatric disorders
0
1
2
1
Insomnia
0
0
1
1
Anxiety
0
1
0
0
Confusional state
0
0
1
0
Cardiac disorders
0
3
0
0
Tachycardia
0
2
0
0
Acute myocardial infarction
0
1
0
0
Atrial fibrillation
0
1
0
0
Cardiac failure
0
1
0
0
Ear and labyrinth disorders
1
0
0
1
Tinnitus
1
0
0
1
Vascular disorders
0
0
2
0
Hypertension
0
0
2
0
Hepatobiliary disorders
0
0
1
0
Hyperbilirubinaemia
0
0
1
0
Immune system disorders
0
0
0
1
Hypersensitivity
0
0
0
1
Neoplasms benign, malignant and unspecified
0
1
0
0
(incl cysts and polyps)
Cancer pain
0
1
0
0
Renal and urinary disorders
0
0
1
0
Azotaemia
0
0
1
0
[0122] Serious adverse events for each treatment group are summarized in Table 10. There were 21 serious adverse events (SAEs) reported by 9 subjects. With exception of one case of thrombocythemia, all other SAE's were classified as unrelated to the TPO mimetic peptide compound. Two of the 21 SAEs reported resulted in death, one subject had cardiac failure and another subject had acute myocardial infarction. The thrombocythemia observed in a subject was reported as being ‘very likely’ related to the TPO mimetic peptide compound. This subject had concurrent severe lung infection and platelets above the normal range at baseline. The subject had thoracotomy and was prescribed antibiotics. This subject also had chronically elevated platelets. Chronically elevated platelets are observed in some subjects with lung cancer.
[0000]
TABLE 10
Treatment-Emergent Serious Adverse Events
Body System or Organ Class
Placebo
1.5 ug/kg
2.25 ug/kg
3.0 ug/kg
Dictionary-derived Term
(N = 12) N
(N = 12) n
(N = 12) n
(N = 10) n
Total no. subjects WITH SERIOUS ADVERSE
1
5
3
0
EVENTS
Blood and lymphatic system disorders
1
2
1
0
Febrile neutropenia
0
0
1
0
Neutropenia
0
1
0
0
Thrombocythaemia
0
1
0
0
Thrombocytopenia
1
0
0
0
Gastrointestinal disorders
0
2
1
0
Abdominal pain
0
1
0
0
Nausea
0
1
0
0
Vomiting
0
0
1
0
Metabolism and nutrition disorders
0
1
2
0
Hyponatraemia
0
0
2
0
Anorexia
0
1
0
0
Dehydration
0
0
1
0
Cardiac disorders
0
2
0
0
Acute myocardial infarction
0
1
0
0
Atrial fibrillation
0
1
0
0
Cardiac failure
0
1
0
0
General disorders and administration site
0
2
0
0
conditions
Fatigue
0
1
0
0
Pain
0
1
0
0
Pyrexia
0
1
0
0
Infections and infestations
0
2
0
0
Lung abscess
0
1
0
0
Respiratory tract infection
0
1
0
0
Respiratory, thoracic and mediastinal
0
1
1
0
disorders
Dyspnoea
0
0
1
0
Respiratory failure
0
1
0
0
Investigations
0
0
1
0
Blood creatinine increased
0
0
1
0
Example 3
[0123] Lung cancer is the leading cause of cancer deaths in the US, with 213,380 new cases and 160,390 deaths in 2007, and non-small cell histology accounts for 80-85% of all cases. 24 At initial staging, approximately 32% of subjects are found to have Stage III disease and 36% have stage IV disease, with five-year survival rates of 8.4% and 1.6%, respectively. 25
[0124] For subjects with Stage IIIB or IV disease, doublet chemotherapy remains the standard, with a platinum-analog as part of the regimen, and often additional radiation for Stage IIIB subjects. Cisplatin or carboplatin have been most commonly tested in combination with other agents, with results for doublet therapy producing modest survival benefits overall. 4, 26-36 A key study, ECOG 1594, compared four different regimens and demonstrated a longer median time to progression for the combination of gemcitabine and cisplatin (4.5 months, 95% CI 3.7-4.8, p=0.001) compared to the other three doublets; but there was no overall survival advantage. 4 The median overall survival for gemcitabine-containing regimens is nine months, and 1-year survival has ranged from 32-40% in various studies. 28,33-35,37 Progression-free survival (PFS) at one year was 14% in one study. 34 In these studies, subjects with performance status 2 did not account for more than 10-15% of those enrolled; the remainder had performance status 0-1.
[0125] Recently, the addition of bevacizumab to paclitaxel/carboplatin has been shown to extend overall survival for subjects with Stage IIIB/IV NSCLC, 38 and has also been evaluated in combination with cisplatin/gemcitabine with demonstration of an improvement in progression-free survival, but not yet overall survival. 39 Toxicities with bevacizumab have somewhat limited its use, however, to selected NSCLC populations. 40
[0126] The toxicity of gemcitabine-containing doublet regimens has been significant in many cases, with hematological toxicity figuring prominently in the safety profile. Grade 3-4 thrombocytopenia has been reported to range from 24 to 56%, and grade 3-4 anemia has been reported in up to 28% of subjects who have received regimens containing either cisplatin/gemcitabine or carboplatin/gemcitabine. 28,33-35,41,42 Among studies where transfusion rates have been described, RBC transfusions and platelet transfusions have been reported in 37 to 41% and 6 to 20% of subjects who were treated with gemcitabine/platinum-analog doublets, respectively. 33,34,35 Information on the use of erythropoiesis-stimulating agents was not reported. Hematological toxicities have often led to dose reductions or dosing delays, so the rationale exists for attempting to deliver more complete dosing if significant chemotherapy-induced anemia and/or thrombocytopenia can be mitigated. Thus, it is reasonable to evaluate the potential for the TPO mimetic peptide compound to prevent or reduce anemia or thrombocytopenia in subjects who are receiving either gemcitabine/cisplatin or gemcitabine/carboplatin chemotherapy for advanced NSCLC.
Overall Rationale for the Study
[0127] Platinum chemotherapy agents (e.g., carboplatin, cisplatin) and platinum-based chemotherapy regimens (e.g., carboplatin and cisplatin given alone or in combination with gemcitabine) are used for the treatment of different types of cancers and have been shown to cause clinically significant bone marrow suppression, leading to decreases in WBCs, RBCs, and platelets, resulting in neutropenia, anemia, and thrombocytopenia, respectively.
[0128] The consequences of myelosuppressive chemotherapy regimens include anemia and/or thrombocytopenia, which can result in impairment in daily activities due to fatigue, the need for RBC or platelet transfusions or treatment with ESAs, delays in chemotherapy schedule, chemotherapy dose reductions, and possibly decreased survival.
[0129] Preclinical pharmacology studies of the TPO mimetic peptide compound have demonstrated a myeloprotective effect of the TPO mimetic peptide compound in prevention of carboplatin or carboplatin and gemcitabine-induced anemia and thrombocytopenia. 23
[0130] Data from studies conducted in healthy subjects and cancer subjects receiving platinum-based chemotherapy are consistent with the efficacy, safety, PK, and PD findings in preclinical studies. These findings suggest that the TPO mimetic peptide compound should be efficacious in the prevention of CIA and/or CIT in cancer subjects receiving platinum-based chemotherapy.
Objectives
[0131] To evaluate the efficacy of the TPO mimetic peptide compound on the prevention of CIA in subjects with non-small cell lung cancer (NSCLC) receiving a 21-day chemotherapy regimen of gemcitabine and either carboplatin or cisplatin.
[0132] To evaluate the efficacy of the TPO mimetic peptide compound on the prevention of CIT in subjects with NSCLC receiving a 21-day chemotherapy regimen of gemcitabine and either carboplatin or cisplatin.
[0133] To evaluate the safety, pharmacokinetics (PK), and pharmacodynamics (PD) of the TPO mimetic peptide compound in subjects with NSCLC receiving a 21-day chemotherapy regimen of gemcitabine and either carboplatin or cisplatin.
[0134] To evaluate the effect of the TPO mimetic peptide compound on subject-reported outcome (PRO) assessments, and to further validate these assessments, in subjects with NSCLC receiving a 21-day chemotherapy regimen of gemcitabine and either carboplatin or cisplatin.
Hypotheses
[0135] In subjects with NSCLC receiving a 21-day chemotherapy regimen of gemcitabine and either carboplatin or cisplatin, co-administration of the TPO mimetic peptide compound provides a lower incidence rate of the composite endpoint of Grade 2 or higher anemia, or a >2 g/dL drop in hemoglobin on the first day of any chemotherapy cycle (Cycle 2 to 6) relative to baseline (Cycle 1, Day 1), or the use of rescue intervention for anemia (e.g., erythropoiesis stimulating agents [ESAs], red blood cell [RBC] transfusion) as compared to placebo.
[0136] In subjects with NSCLC receiving a 21-day chemotherapy regimen of gemcitabine and either carboplatin or cisplatin, co-administration of the TPO mimetic peptide compound provides a lower incidence rate of the composite endpoint of Grade 2 or higher thrombocytopenia or the use of platelet transfusion as compared to placebo.
Overview of Study Design
[0137] In this study, the dose of the TPO mimetic peptide compound or placebo (i.e., dosing solution volume) for each subject is planned to be fixed in Cycles 1 and 2, then modified in subsequent cycles, if necessary, based on the Day 15 platelet count of the previous chemotherapy cycle to optimize subject safety. To further maximize subject safety, hemoglobin values for each subject will also be evaluated on Day 1 of each chemotherapy cycle to determine if the dose of study medication should be held or if a subject should be discontinued from the study. The dose of the TPO mimetic peptide compound or placebo will not be modified based on hemoglobin values.
Study Design
[0138] Subjects with stage IIIB or IV NSCLC, eligible to receive up to 6 cycles of a 21-day chemotherapy regimen of gemcitabine and either carboplatin or cisplatin, will be enrolled prior to their first chemotherapy cycle.
[0139] For each subject, the study will consist of approximately 24 visits. Subject visits will be at: Screening (Visit 1; within Day −14 to Day −1); Day 1, 8, and 15 of Cycle 1 to 6 (Visit 2 to 19); and 5 follow up visits at 30 days after the last dose administration of study medication (Visit 20), and then 6 months (Visit 21), 12 months (Visit 22), 18 months (Visit 23), and 24 months (Visit 24) after Day 1 of Cycle 1 (i.e., 1st dose of chemotherapy). Visit 22, 23, and 24 will require only a telephone call and not a visit to the investigative center. The study duration for each subject will be approximately 24 months (Screening through final follow up visit).
[0140] Subjects who meet the entry criteria will be randomly assigned to receive the TPO mimetic peptide compound (n=74) or placebo (n=74). The study medication will be administered as an IV bolus on Day 1 of each chemotherapy cycle, within 2 hours prior to receiving chemotherapy.
[0141] In a previous study, the maximal effect of the TPO mimetic peptide compound on platelet count was observed on Day 15. Therefore, to ensure subject safety, the dose of the TPO mimetic peptide compound in Cycle 2 to 6 will be adjusted, if necessary, based on the subject's Day 15 platelet count in the previous cycle.
[0142] An overview of the planned the TPO mimetic peptide compound and placebo doses for each cycle are described in Table 11.
[0000]
TABLE 11
Overview of the TPO mimetic peptide compound and Placebo Doses for
Cycle 1 to 6
Cycle
The TPO mimetic peptide compound Dose (μg/kg)
1
2.5
2
3.0 1
3
2.0 to 3.5 2
4
2.0 to 3.5 2
5
2.0 to 3.5 2
6
2.0 to 3.5 2
1 If necessary, the dose will be reduced to 2.5 μg/kg or withheld based on the subject's platelet count on Cycle 1, Day 15 and Cycle 2, Day 1.
2 If necessary, the dose will be titrated or withheld based on the subject's platelet count on Day 15 of the preceding Cycle and Day 1 of this Cycle.
[0143] On Day 1 in Cycle 2, each subject will receive 3.0 μg/kg of the TPO mimetic peptide compound or placebo. In the event a subject's Cycle 1 Day 15 platelet count is >700,000 μL, and the platelet count remains >500,000 μL but is <700,000 μL on Day 1 of Cycle 2, the subject will receive 2.5 μg/kg of the TPO mimetic peptide compound or placebo. If the platelet count is >700,000 μL on Day 1 of Cycle 2, the subject will not be dosed with the TPO mimetic peptide compound or placebo in Cycle 2.
[0144] On Day 1 of Cycle 3 to 6, the dose of the TPO mimetic peptide compound or placebo (i.e., dosing solution volume) will be based on the subject's Day 15 platelet count in the previous cycle.
[0145] In Cycle 2 to 5, if a subject's Day 15 platelet count is >700,000 μL, and the platelet count on Day 1 of the next chemotherapy cycle remains >700,000 μL, the subject will not be dosed with the TPO mimetic peptide compound or placebo for that given cycle. Subjects could be dosed again for subsequent cycles if platelets are <700,000 μL on Day 1 of that chemotherapy cycle. In order to further maximize subject safety, hemoglobin values for each subject will also be evaluated on Day 1 of each chemotherapy cycle to determine if the dose of the TPO mimetic peptide compound or placebo should be held. Specifically, if a subject has a hemoglobin value >15 g/dL or has an increase from baseline of ≧2 g/dL on Day 1 of any cycle, the subject will not be dosed with the TPO mimetic peptide compound for that given cycle. The dose of the TPO mimetic peptide compound or placebo will not be modified based on hemoglobin values.
[0146] A detailed dose titration scheme is provided in Table 12.
[0000]
TABLE 12
The TPO mimetic peptide compound Dose Titration
Scheme for Cycle 3 to 6
Day 15 platelet count of previous
The TPO mimetic peptide
chemotherapy cycle
compound dose (μg/kg) 2,3
(Cycle 2 to 5) ×
for next chemotherapy cycle
1000 (/μL)
(Cycle 3 to 6)
≧900 1
2.0
501-899 1
2.5
101-500
3.0
50-100
3.25
<50
3.5
1 If the subject's platelet count on Day 1 of the next chemotherapy cycle is >700,000/μL, the subject will not be dosed with the TPO mimetic peptide compound or placebo for that given cycle. Subjects could be dosed again for subsequent cycles if platelets are <700,000/μL on Day 1 of that chemotherapy cycle. If platelet count continues to be >700,000/μL on Day 1 of two consecutive cycles, the subject will be discontinued from the study.
2 Placebo subjects will receive the same dosing solution volume of the corresponding THE TPO PEPTIDE COMPOUND dose.
3 If a subject has a hemoglobin value >15 g/dL or has an increase from baseline of ≧2 g/dL on Day 1 of any cycle, the subject will not be dosed with the TPO peptide compound for that given cycle. If hemoglobin continues to be above >15 g/dL, or there is ≧2 g/dL increase from baseline on Day 1 of two consecutive cycles, the subject will be discontinued from the study.
[0147] The control treatment arm (placebo) will be used to establish the frequency and/or magnitude of changes in laboratory and/or clinical endpoints and adverse events that may occur with chemotherapy and standard of care therapies in the absence of the TPO mimetic peptide compound treatment.
[0148] This study is designed to assess the efficacy, safety, PK, and PD of the TPO mimetic peptide compound in male and female subjects with Stage IIIB or IV NSCLC receiving a combination chemotherapy regimen of gemcitabine and either carboplatin or cisplatin.
[0149] The NSCLC population was chosen because the incidence of anemia is high, with Grade 2 or higher anemia reported to range from 38 to 71% with platinum analogs and gemcitabine combinations. The incidence of Grade 3 or higher anemia in this setting has been reported to be as high as 28% (range 5 to 28%), and the incidence of transfusion in this setting has been reported to be approximately 39%. 3,4
[0150] At the time of diagnosis, approximately 68% of the subjects are found to have stage IIIB/IV NSCLC. The 5-year survival is poor (8.4% for stage IIIB and 1.6% for stage IV), in addition, the median overall survival for stage IIIB/IV NSCLC subjects receiving gemcitabine-containing regimens is 9 months. The limited median survival time for these subjects will also permit an exploratory assessment of the safety of the TPO mimetic peptide compound with respect to tumor progression and overall survival in a relatively short period.
[0151] All subjects will receive standard of care treatments, including rescue interventions if necessary, so that clinical outcome for each subject with respect to standard of care treatment is optimized. Subjects will be randomized to receive the TPO mimetic peptide compound or placebo in addition to their standard of care treatment for NSCLC. Erythropoietin, along with other non-investigational hematopoietic agents such as iron, vitamin B, folic acid and red blood cell transfusions, will be allowed as standard of care medicines to treat anemia during the cycles of chemotherapy. The placebo treatment will be used to establish the frequency and magnitude of changes in laboratory and/or clinical endpoints that may occur in the absence of the TPO mimetic peptide compound treatment and thus the placebo dose cohort will allow establishment of the safety of the TPO mimetic peptide compound treatment.
[0152] The composite endpoint of anemia will include the incidence of (1) Grade 2 or higher anemia (i.e. Hb of <10 g/dL), or (2) a ≧2 g/dL drop in hemoglobin on the first day of any chemotherapy cycle (Cycle 2 to 6) relative to baseline (Cycle 1, Day 1), or (3) use of rescue intervention for anemia (e.g., RBC transfusion, ESAs). The components of the composite endpoint were selected based on the following: the current treatment paradigm for ESA use (i.e. ESA use is permitted when the subject's hemoglobin approaches 10 g/dL or is <10 g/dL), a ≧2 g/dL drop in Hb from baseline is considered clinically meaningful, and ESAs and RBC transfusions are rescue interventions for anemia that are accepted as clinically significant events.
[0153] The required chemotherapy regimen of gemcitabine and either carboplatin or cisplatin every 21 days was selected because it is an effective regimen for the treatment of NSCLC. Cancer subjects receiving platinum-based therapies have been reported to demonstrate a decrease in hemoglobin of about 0.5 g/dL at each chemotherapy cycle. The median number of treatment cycles in these subjects has been reported to be 4. Therefore, a decrease in hemoglobin of approximately 2 to 3 g/dL from baseline in the non-TPO mimetic peptide compound treated arm over the 4-6 treatment cycles is anticipated.
[0154] The composite endpoint of thrombocytopenia will include the incidence of (1) Grade 2 or higher thrombocytopenia or (2) the use of platelet transfusion. The components of the composite endpoint were selected based on the following: Grade 2 or higher thrombocytopenia (<75,000 μL platelet count) has been associated with delays in surgical procedures and chemotherapy treatments due to the potential for an increased risk of bleeding, and the use of platelet transfusion is a clinically significant event that is performed to stop or prevent bleeding due to thrombocytopenia.
[0155] Randomization will be stratified based on platinum-based chemotherapy (i.e., carboplatin or cisplatin) and stage of disease (i.e., Stage IIIB or IV) to maintain balance in the active and placebo groups. Carboplatin and cisplatin have similar efficacy profiles and are used with gemcitabine extensively, depending up on the preferences at each treatment center. Randomization will be stratified based on the platinum chemotherapy agent due to their different toxicity profiles. Carboplatin is less nephrotoxic and less emetogenic than cisplatin, and neurotoxicity and ototoxicity are virtually absent. Myelosuppression is the major toxic effect of carboplatin. In contrast, the major toxicities for cisplatin have been nausea, vomiting, and generalized gastrointestinal effects including post-platinum diarrhea. Hydration and dose fractionation mitigate most of the nephrotoxic effect of the cisplatin. The neuropathic effects for cisplatin are relatively common and are related to the cumulative dose administered. Although differences in the safety and efficacy of the TPO mimetic peptide compound in Stage IIIb and IV cancer subjects are not anticipated, the randomization will be stratified by the stage of the disease to detect any potential differences.
[0156] This study is designed as an adaptive dose trial to maximize the safety of each subject by minimizing a transient increase in platelet counts above the normal range.
[0157] The TPO mimetic peptide compound or placebo will be administered within 2 hours prior to chemotherapy. This dose timing is based on the preclinical findings, which indicate that the TPO mimetic peptide compound needs to be administered within one day of the chemotherapy. Dosing within 2 hours prior to chemotherapy in subjects has been chosen with respect to practical considerations of giving chemotherapy supportive care agents (e.g. antiemetics to minimize nausea and vomiting, hydration to minimize nephrotoxiciy) prior to chemotherapy as well as minimize the variability in response to the TPO mimetic peptide compound. Each subject will receive an intravenous bolus dose of the TPO mimetic peptide compound or placebo on Day 1 of each chemotherapy cycle starting from the first cycle up to 6 cycles.
[0158] In Cycle 1 and 2, fixed doses of the TPO mimetic peptide compound or placebo (i.e., dosing solution volume) will be administered. In cycle 1, 2.5 μg/kg dose of the TPO mimetic peptide compound or placebo will be administered. This dose has been chosen based on the results from study in Example 2, where fixed doses ranging from 1.5-3.0 μg/kg were administered. On Day 1 in Cycle 2, each subject will receive 3.0 μg/kg of the TPO mimetic peptide compound or placebo. In the event a subject's Cycle 1 Day 15 platelet count is >700,000 μL, and the platelet count remains >500,000 μL but is <700,000 μL on Day 1 of Cycle 2, the subject will receive 2.5 μg/kg of the TPO mimetic peptide compound or placebo. In Cycle 3 to 6, the dose of the TPO mimetic peptide compound and placebo (i.e., dosing solution volume) will be adjusted based on the subject's Day 15 platelet count from the previous chemotherapy cycle as outlined in Table 11 to maximize safety, particularly with respect to elevated platelets. In all Cycles, the TPO mimetic peptide compound will not be administered if the platelet counts on the day of dosing exceed 700,000 μ/L. Following chemotherapy administration, platelet counts are expected to progressively decline over approximately 2 weeks before starting to recover. Therefore, administering the TPO mimetic peptide compound on Day 1 of each chemotherapy cycle if a subject's platelet count is <700,000 μL is not an anticipated to be unsafe in the presence of chemotherapy agents known to result in thrombocytopenia. Subject safety will be further ensured by discontinuing a subject from the study if platelet count continues to be >700,000 μL on Day 1 of two consecutive cycles.
[0159] An increase in hemoglobin with the use of ESAs has been associated with increased thrombovascular events. In order to further maximize subject safety, hemoglobin values for each subject will also be evaluated on Day 1 of each chemotherapy cycle to determine if the dose of the TPO mimetic peptide compound or placebo should be held. Specifically, if a subject has a hemoglobin value >15 g/dL or has an increase from baseline of ≧2 g/dL on Day 1 of any cycle, the subject will not be dosed with the TPO mimetic peptide compound for that given cycle. Subject safety will be further ensured by discontinuing a subject from the study if hemoglobin continues to be above >15 g/dL or there is ≧2 g/dL increase on Day 1 of two consecutive cycles. A hemoglobin value of 15 g/dL was chosen because it is approximately the upper normal limit in healthy population. A ≧2 g/dL increase in hemoglobin above the baseline (but <15 g/dL) was chosen as it is considered a clinically significant event. The dose of the TPO mimetic peptide compound or placebo will not be modified based on hemoglobin values.
[0160] If a subject is not eligible to be dosed with the TPO mimetic peptide compound in any 2 consecutive chemotherapy cycles, he will not be considered evaluable and will be discontinued form the study. Frequent monitoring of coagulation parameters (e.g., PT, aPTT) will further assess subject safety and if necessary, subjects may be given prophylactic treatment with low dose aspirin.
[0161] Physical exams, vital signs, and ECGs will be assessed as a part of the safety evaluations. In addition, antibodies to the TPO mimetic peptide compound and huTPO will be evaluated over a one-year period. AEs, SAEs, and concomitant medications will be collected for up to 30 days following the last dose of the TPO mimetic peptide compound or placebo. SAEs and AEs beyond the 30 days post last dose of the TPO mimetic peptide compound or placebo will not be followed up as the disease progression in this subject population will make it difficult to assess the relationship of AEs to the TPO mimetic peptide compound beyond 30 days after the last dose of the TPO mimetic peptide compound.
[0162] Tumor assessments will be performed every two chemotherapy cycles (i.e., 6 weeks), or more frequently according to standard clinical practice for up to 6 months. This period is considered adequate to identify a potential trend for a deleterious effect of the TPO mimetic peptide compound on tumor growth in this subject population, as the median survival for this subject population is only 9 months. Progression-free survival will be evaluated at 6 months, and overall survival over a 2-year period, both will be considered exploratory safety evaluations.
[0163] Several specialized PD parameters will be evaluated. The measurement of coagulation parameters (Platelet Factor 4, prothrombin fragments 1+2, fibrin split product [D-dimer]; fibrinogen, and P-selectin) will assess the effect of the TPO mimetic peptide compound on functional coagulation. A reduction in fibrinogen levels may suggest prevention of development of microangiopathies that may also contribute to the prevention of chemotherapy-induced thrombocytopenia and anemia. These coagulation markers will enable assessment of any potential for increased thrombovascular events with increased platelets due to the TPO mimetic peptide compound treatment. Measurement of platelet derived growth factor-AA (PDGF-AA) and transforming growth factor-beta-1 (TGF β1 ) will be utilized to assess bone remodeling. Measurement of hematopoietic and thrombopoietic growth factors (serum huTPO and huEPO) will determine whether the TPO mimetic peptide compound has any affect on these growth factors, which are associated with maintenance and control of the level of the hemoglobin and platelet count endpoints.
[0164] PK samples will be collected to determine plasma concentrations of the TPO mimetic peptide compound and potentially determine a PK/PD relationship.
[0165] Subject Reported Outcomes assessments will be performed to explore the effects of the TPO mimetic peptide compound on a subject's daily function, fatigue, and other related measures. The Functional Assessment of Cancer Therapy-Anemia (FACT-An), Brief Fatigue Inventory (BFI), and Global Impression of Change (GIC) will be utilized for assessing subject reported outcomes.
[0166] A starting dose of 2.5 μg/kg in cycle 1 was chosen based on the results from an ongoing study in subjects with cancer, which investigated 1.5, 2.25 and 3 μg/kg doses.
[0167] Dose related platelet elevations are an expected pharmacological effect of the TPO mimetic peptide compound. As a result, at higher doses it is possible that excessive platelet elevations (beyond normal range) are observed. In the ongoing clinical study, at 1.5 and 2.25 μg/kg doses, none of the subjects had a ≧3-fold increase from baseline in platelet count. In contrast, at 3.0 μg/kg dose, two subjects had a ≧3-fold increase from baseline in platelet count around Day 15; the increase was transient and they were not considered adverse events. In the second cycle, after administration of the 3.0 μg/kg dose, the increase in platelet count observed was approximately 2-fold higher than baseline. This reduced elevation in platelet count relative to the increase in the first cycle was most likely due to cumulative myelosuppression as a result of continued chemotherapy. Elevated platelet counts of ≧3-fold increase from baseline have been observed in healthy subjects also at the 3.0 μg/kg dose. Therefore, it is planned to modify the doses of the TPO mimetic peptide compound for each subject in subsequent cycles (i.e., Cycle 2 to 6) based on the Day 15 platelet counts of the previous chemotherapy cycle, which is the anticipated to be the peak time for platelet count. This will allow optimal balancing of safe and efficacious doses. Therefore, a starting dose of 2.5 μg/kg body weight is considered appropriate. Based on the results from study, it is anticipated that due to cumulative myelosuppression resulting from continued chemotherapy, reduced platelet elevation is expected to be observed in subsequent cycles with the same dose of the TPO mimetic peptide compound. Therefore, the dose in the second cycle is planned to be 3.0 μg/kg (unless the Day 15 platelet data from cycle 1 do not support an increase in the dose in the second cycle as explained earlier).
[0168] It is anticipated that due to cumulative bone marrow toxicity of chemotherapy, higher doses of the TPO mimetic peptide compound are likely to be needed to achieve the similar response in the subsequent cycles as the previous cycles. The dose titration range for Cycle 3 to 6 is 2.0 to 3.5 μg/kg. The highest dose of 3.5 μg/kg has been proposed in the event very low platelet counts are observed on Day 15 (i.e. <50,000 μL).
Individual Subject Stopping Criteria
[0169] An individual subject will be discontinued from the study if the following occurs at anytime during study participation:
If platelet count continues to be >700,000 μL on Day 1 of two consecutive cycles If hemoglobin continues to be above >15 g/dL or there is ≧2 g/dL increase on Day 1 of two consecutive cycles Subject is withdrawn for reasons such as below.
Withdrawal from the Study
[0173] A subject may be withdrawn from the study for any of the following reasons:
Tumor progression resulting in discontinuation of chemotherapy Discontinuation of study treatment. If a subject discontinues treatment before the end of the treatment phase, the first follow up visit should be performed. A subject may be discontinued from study treatment if:
The investigator believes that for safety reasons (e.g., adverse event) it is in the best interest of the subject to stop treatment
Individual Stopping Criteria: If platelet count continues to be >700,000 μL on Day 1 of two consecutive cycles Subject will be discontinued from the study if hemoglobin continues to be above >15 g/dL or there is ≧2 g/dL increase on Day 1 of two consecutive cycles The subject becomes pregnant If a subject is not dosed with the TPO mimetic peptide compound in any 2 consecutive chemotherapy cycles, the subject will be withdrawn from the study. Death
Dosage and Administration
[0184] On Day 1 of each chemotherapy cycle, subjects will receive an IV bolus dose of the TPO mimetic peptide compound or matching placebo (0.9% sodium chloride for injection) within 2 hours prior to receiving chemotherapy.
[0185] On Day 1 in Cycle 1, each subject will receive 2.5 μg/kg of the TPO mimetic peptide compound or placebo.
[0186] On Day 1 in Cycle 2, each subject will receive 3.0 μg/kg of the TPO mimetic peptide compound or placebo. In the event a subject's Cycle 1 Day 15 platelet count is >700,000 μL, and the platelet count remains >500,000 μL but is <700,000 μL on Day 1 of Cycle 2, the subject will receive 2.5 μg/kg of the TPO mimetic peptide compound or placebo.
[0187] On Day 1 of Cycle 3 to 6, the dose of the TPO mimetic peptide compound or placebo (i.e., dosing solution volume) will be based on the subject's Day 15 platelet count in the previous cycle. The dose titration scheme for Cycle 3 to 6 is provided in Table 11.
Gemcitabine, Carboplatin, and Cisplatin
[0188] The following chemotherapy regimens are required for eligibility:
Gemcitabine: Dose=1000 to 1250 mg/m 2 ; administered as a 30 minute infusion on Day 1 and Day 8 of each 21-day chemotherapy cycle
[0190] And, either
Carboplatin: Dose=5 to 6 (target AUC of Carboplatin)×(GFR+25); administered on Day 1 of each 21-day chemotherapy cycle
[0192] Or
Cisplatin: Dose=75 to 80 mg/m 2 ; administered on Day 1 of each 21-day chemotherapy cycle
[0194] After completion of Cycle 1 (Visit 2), if necessary per clinical judgment, the chemotherapy doses may be modified according to the approved product label in the respective country of the investigative site.
Study Evaluations
Overview
[0195] The approximate blood volume that will be collected for each subject is summarized in Table 13.
[0196] Blood samples will be collected from an intravenous cannula or by direct venipuncture. If an indwelling cannula is used for blood sample collection, a small amount of blood (i.e. no more than 1 mL) will be discarded each time a sample is taken via the cannula.
[0000]
TABLE 13
Approximate Blood Volume Collected Per Subject
Blood
volume
Total
Total blood
per sample
number of
volume
Procedure
(mL)
samples
(mL)
Serology
5
1
5
Chemistry
5
8
40
Hematology
4
21
84
Coagulation
2
21
42
Serum iron, B 12 , TIBC, ferritin
7
1
7
Antibody formation to the TPO
3
2
6
mimetic peptide compound
Antibody formation to huTPO
3
2
6
PK
1
8
8
Fibrinogen, F1 + 2, D-dimer
4.5
3
13.5
PF4
2.7
3
8.1
Soluble P-selectin, TGF β , PDGF
4
3
12
Serum huTPO
1.5
3
4.5
Serum huEPO
1.5
3
4.5
Approximate Subtotal
~241
mL
Serum pregnancy test
5
2
10
(women of childbearing potential)
Approximate Total
~263
mL
[0197] Visit 2 to 19: Double-Blind Treatment Phase
[0198] Subjects will arrive at the investigative center on the morning of Day 1, 8, and 15 of each 21-day chemotherapy cycle for up to 6 cycles (Cycle 1 to Cycle 6). Visit 2, 5, 8, 11, 14, and 17 correspond to Day 1 of each chemotherapy cycle (Cycle 1 to 6).
[0199] Visit 3, 6, 9, 12, 15, and 18 correspond to Day 8 of each chemotherapy cycle (Cycle 1 to 6). Each of these visits may be conducted +/−2 days.
[0200] Visit 4, 7, 10, 13, 16, and 19 correspond to Day 15 of each chemotherapy cycle (Cycle 1 to 6). Each of these visits may be conducted +/−2 days.
[0201] Predose is defined as within 2 hours of study medication administration. The pharmacokinetic sample scheduled for predose should be taken as close to the dosing time as possible. The Visit 2 predose results will be considered the subject's baseline values for statistical analyses.
Efficacy
Evaluations and Criteria
Primary
[0202] The primary efficacy evaluation will be the difference in incidence rates between the TPO mimetic peptide compound and placebo on the composite endpoint of Grade 2 or higher anemia, or a ≧2 g/dL drop in hemoglobin on the first day of any chemotherapy cycle (Cycle 2 to 6) relative to baseline (Cycle 1, Day 1), or the use of rescue intervention for anemia.
[0203] Hemoglobin and the use of ESAs and RBC transfusions will be the criteria used to evaluate the primary efficacy endpoint. These parameters will also be part of the safety evaluation.
[0204] Anemia will be graded based on the Common Terminology Criteria for Adverse Events (CTCAE): Version 3.0. 55 CTCAE Version 3.0 criteria for hemoglobin can be found in Attachment 1.
Secondary
[0205] The secondary efficacy endpoints are:
The difference between the TPO mimetic peptide compound OUND and placebo on the incidence rates on the composite endpoint of Grade 2 or higher thrombocytopenia or the use of platelet transfusion. The difference between the TPO mimetic peptide compound and placebo on the incidence rates of each individual component of the composite endpoint for anemia and thrombocytopenia.
[0208] Hemoglobin, platelet count, use of ESAs, and the use of RBC and platelet transfusions will be the criteria used to evaluate the secondary efficacy endpoints. These parameters will also be part of the safety evaluation.
[0209] Thrombocytopenia and anemia will be graded based on the Common Terminology Criteria for Adverse Events (CTCAE): Version 3.0. 55
Pharmacokinetic Evaluations
[0210] Venous blood samples of 1 mL will be collected for determination of the TPO mimetic peptide compound plasma concentrations.
Pharmacokinetic Parameters
[0211] Individual plasma concentration data from each sample time point will be determined.
Pharmacodynamic Evaluations
[0212] The following PD evaluations will be performed:
Coagulation parameters: Fibrinogen, platelet factor 4 (PF4), prothrombin fragments 1+2 (PF1+2), fibrinogen degradation product (D-dimer), and P-selectin. These parameters will also be a safety evaluation. Marker for bone remodeling: Platelet derived growth factor-AA (PDGF-AA) and transforming growth factor-beta-1 (TGF β1 ). These parameters will also be a safety evaluation. Human growth factors: Serum native human thrombopoietin (huTPO) and erythropoietin (huEPO) concentrations.
Laboratory Tests
[0216] Venous blood samples for serum chemistry, hematology, coagulation, and a random urine sample for urinalysis will be collected. Several laboratory tests (e.g., hemoglobin, platelet count) will also be efficacy evaluations.
Hematology
Hemoglobin
Hematocrit
[0217] Platelet count
Red blood cell count
Percent reticulocytes
White blood cell count with differential
Red blood cell indices (MCHC, MCV, MCH, RDW)
Urinalysis—Sediment (Performed Only if Dipstick is Abnormal)
[0218] If dipstick result is abnormal, flow cytometry will be used to measure sediment. In case of discordance between the dipstick results and the flow cytometric results, the sediment will be examined microscopically.
[0000]
Red blood cells
Crystals
White blood cells
Casts
Epithelial cells
Bacteria
Other
[0219]
[0000]
Iron
Folate
B 12
TIBC
Ferritin
Antibody Formation
[0220] Venous blood samples will be obtained to determine the antibody titers against huTPO and the TPO mimetic peptide compound. Serum will be analyzed.
Tumor Response Assessment
[0221] Tumor assessment will be performed and evaluated per RECIST criteria. 43,44
[0222] The same procedure (e.g., CT, MRI) used for tumor assessment at Screening must be used throughout the entire study.
Progression-Free Survival
[0223] Tumor response assessment will allow an evaluation of progression free survival at 6 months.
[0224] Progression free survival (PFS), computed for all randomized subjects, is defined as the time from randomization until the time of disease progression is first documented. Subjects who die without a reported prior progression will be considered to have progressed on the date of their death. Subjects who have not progressed or died will be censored on the date of their last tumor assessment (i.e., 6 months from first dose of study medication).
Overall Survival
[0225] Overall survival, computed for all randomized subjects, is defined as the date of first dosing until the time death is documented. Overall survival will be assessed over a period of 24 months from first dose of study medication. Subjects who have not died will be censored on the date of the last follow up visit.
Other Safety Evaluations
[0226] The following will be evaluated throughout the study:
Incidence of the use of rescue intervention for anemia or thrombocytopenia Incidence of a delay in administration or a dose reduction in chemotherapy Incidence of a dose reduction in study medication dose Incidence of thrombovascular events (TVE)
Functional Assessment of Cancer Therapy—Anemia (FACT-An)
[0231] The Functional Assessment of Cancer Therapy—Anemia (FACT-An) is a 47-item subject reported outcome measure that was developed to assess fatigue and anemia related concerns in people with cancer. It includes the FACT-General (FACT-G) consisting of physical, functional, emotional, and social/family well-being subscales (27 items), and the anemia scale consisting of fatigue (13 items) and non fatigue (7 items) subscales. 49, 50 The FACT items are rated on a 5-point Likert-type scale ranging from 0 “not at all” to 4=“very much”. Higher scores represent better health status or less severe symptoms. FACT-An scores have been shown to be associated with hemoglobin levels in subjects undergoing chemotherapy. 48
Brief Fatigue Inventory (BFI)
[0232] The BFI was developed and validated with subjects with cancer experiencing treatment or disease-related anemia. 51
[0233] The BFI includes 3 items that address fatigue severity (weariness, tiredness) “now”, “usual level of fatigue over last 24 hours” and “worst level of fatigue over the last 24 hours.” An additional 6 items assess the extent to which fatigue interferes with general activity, mood, walking ability, normal work, relations with other people, and enjoyment of life. Each item includes an 11-point numeric rating scale ranging from 0 (no fatigue or interference) to 10 (as bad as you can imagine or completely interferes).
Global Impression of Change (GIC)
[0234] For purposes of further validation of the BFI, subjects will be asked provide an assessment of their global impression of change in fatigue using a single item measure. This measure is included in order to associate observed changes in the BFI to subject perceptions of change in fatigue. Specifically this will assist in evaluating the responsiveness and clinically meaningfulness of observed change in the BFI.
Data Analysis
Efficacy Analyses
[0235] Efficacy analyses will be performed on all subjects receiving at least one dose of the TPO mimetic peptide compound or placebo and with at least one efficacy assessment.
Primary
[0236] The primary efficacy evaluation will be the difference in incidence rates between the TPO mimetic peptide compound and placebo on the composite endpoint of Grade 2 or higher anemia, or a ≧2 g/dL drop in hemoglobin on the first day of any chemotherapy cycle (Cycle 2 to 6) relative to baseline (Cycle 1, Day 1), or the use of rescue intervention for anemia.
[0237] In order to account for potential differences in follow up, the composite endpoint incidence rates for the active and placebo groups will be estimated using the Kaplan-Meier approach, with Greenwood formula estimates of the standard deviations. A 90% (two-sided) confidence interval on the difference in incidence rates will be provided. As an additional sensitivity analysis, the time to reach the composite endpoint will also be evaluated using the relative risk estimate from the Cox regression model with baseline hemoglobin level (predose at Visit 2) as a covariate and disease stage and platinum chemotherapy regimen as factors in the model.
Secondary
[0238] The secondary efficacy evaluations are:
The difference in incidence rates between the TPO mimetic peptide compound and placebo on the composite endpoint of Grade 2 or higher thrombocytopenia or the use of platelet transfusion. The difference between the TPO mimetic peptide compound and placebo on the incidence rates of each individual component of the composite endpoint for anemia and thrombocytopenia.
[0241] The secondary efficacy evaluation of the incidence rates of the composite endpoint for thrombocytopenia (Grade 2 or higher thrombocytopenia or the use of platelet transfusion) will be analyzed as described above for the primary efficacy evaluation.
[0242] Each component of the composite endpoints for anemia and thrombocytopenia will also be evaluated in a similar fashion.
Pharmacokinetics
[0243] Data will be listed for all subjects with available plasma concentrations per treatment. All concentrations below the limit of quantification (LOQ) or missing data will be labeled as such in the concentration data listings. Concentrations below the LOQ will be treated as zero in the summary statistics. All subjects and samples excluded from the analysis will be clearly documented in the study report.
[0244] Data for all subjects receiving at least one dose of active TPO mimetic peptide compound will be included in the pharmacokinetic analyses. Descriptive statistics (including means, median, standard deviations and coefficients of variation) of concentration data will be generated for each dose.
Pharmacodynamic Analyses
[0245] Pharmacodynamic analyses will be performed on all subjects receiving at least one dose of the TPO mimetic peptide compound or placebo and with at least one pharmacodynamic assessment. Summary statistics will be generated for all pharmacodynamic parameters.
Pharmacokinetic/Pharmacodynamic Analyses
[0246] Where appropriate, plasma and blood concentrations and corresponding pharmacodynamic measurements will be plotted to evaluate their relationship.
TPO Mimetic Peptide Compound Information
Physical Description of the TPO Mimetic Peptide Compound
[0247]
[0000]
Strength:
2.0 mg/mL solution, after reconstitution
Dosage form:
Intravenous solution
Placebo:
Intravenous 0.9% saline for injection
[0248] The TPO mimetic peptide compound will be provided as a lyophilized powder for reconstitution (2.0 mg/mL solution after reconstitution). The lyophilized powder (5 mg PEGylated peptide) is in a single-use 3- or 4 mL glass vial.
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Attachment 1
Assessment of Hemoglobin and Platelet Count Using the Common Terminology Criteria for Adverse Events (Version 3.0)
[0304]
[0000]
Common Terminology Criteria for Adverse Events (CTCAE): Version 3.0
Grade
Definition
Hemoglobin
Platelets
0
No Adverse Event
WNL
WNL
or within
normal limits
1
Mild Adverse Event
<LLN-10.0 g/dL
<LLN-
<LLN-6.2 mmol/L
75,000/mm 3
<LLN-100 g/L
<LLN-75.0 × 10 9 /L
2
Moderate Adverse
<10.0-8.0 g/dL
<75,000-
Event
<6.2-4.9 mmol/L
50,000/mm 3
<100-80 g/L
<75.0-50.0 × 10 9 /L
3
Severe and
<8.0-6.5 g/dL
<50,000-
undesirable
<4.9-4.0 mmol/L
25,000/mm 3
Adverse Event
<80-65 g/L
<50.0-25.0 × 10 9 /L
4
Life-threatening or
<6.5 g/dL
<25,000/mm 3
disabling adverse
<4.0 mmol/L
<25.0 × 10 9 /L
event
<65 g/L
5
Death related to
Death
Death
Adverse Event
|
The present invention provides a method for treating hematological disorders such as anemia and thrombocytopenia, whereby a TPO mimetic peptide compound is administered using a specified dosing regimen. The dosing regimen involves the administration of the TPO mimetic peptide compound within a specified time frame surrounding administration of a chemotherapeutic agent. The dosing regimen also involves monitoring subject response in order to determine future course of treatment.
| 0
|
BACKGROUND OF THE INVENTION
As is well known, Stirling cycle cryogenic refrigerators, or cryocoolers, use a motor driven compressor to impart a cyclical volume variation in a working volume filled with pressurized refrigeration gas. The pressurized refrigeration gas is fed from the working volume to one end of a sealed cylinder called a cold head. An annular heat exchanger or regenerator is positioned inside the cold head. The regenerator has openings in either end to allow the refrigeration gas to enter and exit.
The compressor and expander reciprocate in a fixed relationship creating the volume variations in the working space and forcing the refrigeration gas to flow through the regenerator in alternating directions. One end of the regenerator is above ambient temperature during operation while the other end is at a cryogenic temperature. Gas enters the expander at cryogenic temperature and as the gas expands it absorbs heat, ideally, at constant temperature. The device to be cooled is mounted adjacent the expansion space, on the cold end of the cold head.
Because the cold head is sealed, the volume of the expansion space also varies as the expander reciprocates. The efficiency of a Stirling cryocooler is optimized by properly timing the movement of the expander. Specifically, its movement should be such that the variations in the volume of the expansion space lead the variations in the volume of the compression space by approximately 90°. This insures that The working volume's pressure and temperature are at a peak before the refrigeration gas enters the regenerator from the working volume.
The two most common configurations of Stirling cryocoolers are referred to as "split" and "integral". The split Stirling type has a compressor which is mechanically isolated from the expander. Cyclically varying pressurized gas is fed between the compressor and expander through a gas transfer line. In most split Stirling cryocoolers proper timing of expander movement is achieved by using precision friction seals.
In an integral Stirling cryocooler, the compressor, heat exchangers, regenerator and cold head are assembled in a common housing. The typical arrangement uses an electric motor to drive the moving parts. A crankshaft, disposed in a crankcase, is used to properly time compressor and expander movement, much as an internal combustion engine uses a crankshaft to provide proper timing of the movement of its parts. As such, the typical integral cryocooler requires several bearings to support the crankshaft. If connecting rods are used to couple the compressor and expander to the crankshaft, additional bearings are required. One problem with this arrangement is that these bearings require a lubricant. Unfortunately, lubricants are subject to freezing at cryogenic temperatures and consequently must be prevented from freezing and plugging the regenerator. Many different sealing arrangements have been used. Some Stirling systems use contact seals of the wearing type along with hydro formed bellows to prevent lubricant from reaching the regenerator. However, these arrangements produce wear particles which result in limited operating life.
One way to prevent oil containing refrigerant gas in the crankcase from reaching the oil-free refrigerant gas in the regenerator is to use a bellows seal. Bellows seals have been found to be particularly suited for this application. The bellows configurations have been stacked or axially spaced and have excessive height/length requirements.
SUMMARY OF THE INVENTION
The piston structure of the Stirling cycle device of the present invention is unusual in that the piston is made up of a seal portion and a guide portion. There are no piston rings or the like and the seal portion moves in a bore with a very small clearance but without contact between the seal portion and the bore because of the need to be free of lubricant and particles produced by wear. The length of the seal portion as well as the clearance determines the pressure drop across the seal portion. The guide portion is separated from the oil-free refrigerant by the bellows seal. The guide portion coacts with a bore to guide the movement of the piston seal. To prevent the piston from canting and permitting the seal portion to contact its bore, it is necessary to locate the guide portion in a long bore with small clearances. Because efficient operation of the cryocooler requires maintaining extremely small, critical dimensional tolerances, even the minute contaminations carried in the lubricant cause unacceptable wear of the moving parts, which in turn severely shortens operating life.
The stacked or axially spaced distribution of the conventional piston, cylinder and bellows of a conventional Stirling cycle device is replaced with a telescoping arrangement. Specifically, the guide portion of the cylinder is at least partially located within and axially coextensive with the bellows thereby providing a reduction in the height/length of the piston, cylinder and bellows assembly.
It is an object of this invention to reduce the piston, cylinder and bellows assembly height in a Stirling cycle device.
It is another object of this invention to reduce the weight of the pistons in a Stirling cycle device.
It is a further object of this invention to reduce the distance between the guide surface and the top of the piston and thereby the moment arm for canting. These objects, and others as will become apparent hereinafter, are accomplished by the present invention.
Basically, a portion of the guide portion of the cylinder is formed as an axially extending tubular portion or collar. The bellows surrounds, and is at least partially axially coextensive with the collar whereby relative movement is in the nature of a telescoping action.
BRIEF DESCRIPTION OF THE DRAWINGS
For a fuller understanding of the present invention, reference should now be made to the following detailed description thereof taken in conjunction with the accompanying drawings wherein:
FIG. 1 is a schematic representation of a Stirling cycle device employing the present invention;
FIG. 2 is a partially sectioned view of a portion of the expander assembly of a Stirling cycle device with the piston at top dead center;
FIG. 3 is similar to FIG. 2 except that the piston is at bottom dead center;
FIG. 4 is similar to FIG. 3 except that it shows additional portions of the cold head;
FIG. 5 is a partially sectioned view of the compressor in the top dead center position; and
FIG. 6 is a sectional view of the bellows showing its attachment structure.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In FIGS. 1-5 the numeral 10 generally designates a Stirling cycle cryocooler having a crankcase 12. Crankcase 12 has an oil sump 13 and is filled with oil laden helium as a result of lubricating parts within crankcase 12. A motor (not illustrated) is located within crankcase 12 and via crankshaft 44 drives piston 30 of expander 31 and piston 130 of compressor 131. Referring specifically to FIG. 1, it will be noted that piston 30 is sealed with respect to crankcase 12 by bellows 24 and, similarly, piston 130 is sealed with respect to crankcase 12 by bellows 124. It will be noted that crankcase 12 and bellows 24 define a chamber 34 that is fluidly isolated from the interior of crankcase 12. Similarly, crankcase 12 and bellows 124 define a chamber 134 that is fluidly isolated from the interior of crankcase 12. Chambers 34 and 134 are, however, connected through buffer chamber 50. Buffer chamber 50 is separated from chamber 54 by diaphragm 52 and chamber 54 is in fluid communication with the interior of crankcase 12. Expander 31 and compressor 131 are connected via line 59, regenerator 60 and line 61.
The gas in regenerator 60 and in chambers 34, 50 and 134 as well as in expander 31 and compressor 131 is pure helium. In operation of the FIG. 1 system, compressor 131 is driven approximately 90° ahead of expander 31. On the discharge stroke of piston 130, helium is forced from compressor 131 through regenerator 60 for approximately 90° of rotation before expander 31 starts its suction stroke. When expander 31 starts its suction stroke, the helium expands and thereby cools providing a refrigerating effect at the cold head 62. When compressor 131 starts its suction stroke piston 30 is approximately at bottom dead center so that as expander 31 goes to the discharge stroke compressor 131 has created a pressure differential across regenerator 60 causing reverse flow through regenerator 60 from expander 31 to compressor 131. As pistons 30 and 130 reciprocate, the chambers 34 and 134 are, effectively, diaphragm pumps and chamber 50 accommodates the pressure and volume changes.
Referring now specifically to FIGS. 2-4 crosshead 14 is sealed and secured to crankcase 12 by bolts or other suitable structure and suitable seals (not illustrated). Crosshead 14 includes a cylindrical portion 14-1 defining a piston bore 14-2. Cylindrical portion 14-1 is received within heat exchanger 16 of the expander assembly. Crosshead 14 further includes coaxial tubular portions 14-3 and 14-4 which define bore 14-5. Annular, lower terminal 18 is suitably secured to crosshead 14 by bolts or the like and surrounds tubular portion 14-3. O ring or other suitable seal 20 provides a fluid seal between lower terminal 18 and crosshead 14. Annular bellows 24 is secured to lower terminal 18 in a suitable fluid tight manner, as by welding.
Referring specifically to FIG. 2, piston 30 includes a piston head having an annular cylindrical portion 30-1 received in bore 14-2 in a non-contacting relationship so as to define a seal portion and integral guide rod 30-2 which is reciprocatably received in bore 14-5 so as to define a guide portion. Guide rod 30-2 is secured to clevis 40 and thereby strap 42 and crankshaft 44 in any suitable conventional manner. Annular upper terminal 22 is welded or otherwise suitably secured in a fluid tight manner to cylindrical portion 30-1 of piston 30 and to bellows 24.
Tubular portion or collar 14-3, lower terminal 18, the interior surface of bellows 24, upper terminal 22 and the interior of cylindrical portion 30-1 define a chamber 32 which is in fluid communication with the interior of crankcase 12 via bore 14-6 in crosshead 14. A second chamber 34 is defined by the exterior surface of bellows 24, lower terminal 18, upper terminal 22 and bore 14-2. Chamber 34 has a restricted communication across piston 30 via the clearance between cylindrical portion 30-1 and bore 14-2 and is in fluid communication via bore 14-7 with buffer chamber 50. Buffer chamber 50 is separated from buffer chamber 54 by diaphragm 52. Buffer chamber 54 is in communication with the interior of crankcase 12 via bore 12-1.
The regenerator 60, as best shown in FIG. 4, is integral with and located above heat exchanger or cooler 16 and includes cylinder 16-1 located in upper casing or shell 16-2 and cold head 62. The annular space between cylinder 16-1 and shell 16-2 is filled with wire screen or mesh 60-1 which functions as the regenerator. Cylinder 16-1 generally forms a continuation of bore 14-2 and receives piston head or dome 30-3 which is secured to piston 30 in any suitable manner so as to be integral therewith. Piston head or dome 30-3 is made of very thin stainless steel so as to have very low heat conduction. This results in reduced heat transfer between the cold gas passing into cylinder 16-1 and piston 30. The piston head or dome 30-3 has a larger clearance with cylinder 16-1 than does piston 30 and bore 14-2 since more radial movement of piston head or dome 30-3 is possible because of its greater distance from bore 14-5 which receives and guides the guide rod 30-2. Helium gas passing from compressor 131 via line 61 enters bore 16-3 in lower casing 16-4 and then passes into annular chamber 16-5. The helium gas passes from annular chamber 16-5 into capillary tubes 17 through screen or mesh 60-1 of regenerator 60 in upper casing 16-2 and over cold head 62. The annular space between cylinder 16-1 and upper casing 16-2 defines a portion of line 59 of FIG. 1. The helium gas is drawn into cylindrical portion 16-1 via line 59 by the suction stroke of piston 30 and its integral piston head or dome 30-3. During the discharge stroke the flow is reversed. Heat exchanger 16 further includes inlet port 16-6 and outlet port 16-7 which are connected via annular chamber 16-8 which surrounds the chamber containing capillary tubes 17. Therefore, when a suitable heat transfer medium is supplied to port 16-6, the capillary tubes 17 are cooled as is the gas flowing through tubes 17.
Compressor 131, as best shown in FIG. 5, is structurally similar to expander 31 and corresponding structure has been numbered 100 higher and is functionally similar to the corresponding structure of expander 31. Cover 146 is suitably secured to crankcase 12 and coacts with bore 114-2 of crosshead 114 to define the gas volume being compressed by piston 130. Cover 146 has a bore 146-1 connected to line 61. Bore 114-7 is connected to chamber 50. The coaction of piston 130 and bellows 124 is the same as that of piston 30 and bellows 24.
Referring now to FIG. 6, it will be noted that the bellows 24 is made up of a plurality of Bellville washer type or other suitable elements 24-1 which are welded together in a stack to form a fluid tight unit. Specifically, each intermediate element 24-1 is welded at its outer periphery to one adjacent element 24-1 and at its inner periphery to another adjacent element 24-1. The bottom element is welded to annular lower terminal 18 and the top element is welded to annular upper terminal 22. Bellows 124 is similarly constructed.
In operation, crankshaft 44 is rotated by a motor (not illustrated) which, in turn, drives strap 42 of the expander 31 and strap 142 of the compressor 131. Straps 42 and 142 are approximately 90° out of phase so that the piston 130 of the compressor 131 is driven approximately 90° ahead of piston 30. In comparing the top dead center position of FIG. 2 with the bottom dead center of FIG. 3, it will be noted that chambers 32 and 34 each have their greatest volumes in their FIG. 2 position and their smallest volumes in their FIG. 3 position. As a result, chambers 32 and 34 are, effectively, pumping volumes during the operation of the cryocooler 10. Starting with the FIG. 2 position of the device, chambers 32 and 34 are at a maximum, as noted. As piston 30 moves from the FIG. 2 position towards the FIG. 3 position, refrigerant gas in chamber 32 will return to crankcase 12 via bore 14-6 in crosshead 14. Additionally refrigerant gas from chamber 34 will be forced into buffer chamber 50 via bore 14-7 and will act on diaphragm 52 in opposition to the refrigerant in chamber 54 which is at crankcase pressure. Diaphragm 52 will be positioned responsive to the pressure differential between chambers 50 and 54 and will, therefore, in effect, act as a diaphragm pump. Because of the clearance seal formed by the small clearance between cylindrical portion 30-1 and bore 14-2 the pressure differential will normally be less than 10 psi. In further comparing FIGS. 2 and 3 it will be noted that cylindrical portion 30-1 of piston 30 is able to move to a position in which the axial spacing between tubular portion 14-3 and cylindrical portion 30-1 is minimal, or even negative, and the height/length of the assembly is thereby reduced by an amount corresponding to the height/length of the bellows. The foregoing description of expander 31 also applies to the corresponding structure of compressor 131 which is numbered 100 higher, as noted above.
Although a preferred embodiment of the present invention has been illustrated and described, other changes will occur to those skilled in the art. It is therefore intended that the scope of the present invention is to be limited only by the scope of the appended claims.
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The guide portion of the cylinder of a Stirling cycle device is located at least partially within and is axially coextensive with the bellows thereby providing a reduction in the height/length of the piston, cylinder and bellows assemblies. The reduction is the distance between the guide surface and the top of the piston reduces the moment arm for canting.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to a stretch of gene promoter capable of activating expression specifically in plant tissue, and in particular, to a promoter capable of activating expression specifically in calyx, petal and stamen of a plant floral organ, as well as to the application of said promoter.
[0003] 2. Description of the Prior Art
[0004] In transgenic plants, the target gene to be transferred into the plant has to be constructed downstream of a promoter usable by the plant. After transformation, the expression of said target gene in the transgenic plant can be activated by the action of said promoter. The CaMV 35S promoter is the most commonly used promoter for driving target gene expression in plants. However, CaMV 35S promoter does not exhibit tissue specificity, and hence can not carry out the expression of the target gene in a specific plant tissue to achieve the purpose of modulating a gene expression. Further, it exhibits lower activity in monocot plants, such as orchid, than in dicot plants.
[0005] In some cases, constitutive over-expression of a transgenic target gene may interfere with the normal physiological processes in a plant. The development of tissue-specific promoters to drive a particular gene of interest should help to alleviate these problems. Therefore, the isolation and development of floral specific promoters from monocots is necessary. To modulate the expression of a target gene in transgenic plants, the critical point for modulating a gene expression is how to make a strong expression of a target gene at a specific tissue organ and/or a specific phase other than carrying out a strong expression of a target gene in the transgenic plant. Therefore, one of the important topics in promoting industrial development is to screen each promoter with different a specificity that can be used as various tools for modulating gene expression so that the transferred promoter can support the production of recombinant protein, as well as a promoter having activating ability with space specificity so as to attain the function of modulating gene expression and hence increase economical benefit.
[0006] In view of the foregoing, it is evident that CaMV 35S promoter has many disadvantages, is not designed perfectly and needs to be urgently improved.
[0007] The inventor had recognized various disadvantages derived from the conventional CaMV 35S promoter described above, and had devoted to improve and innovate. After studying intensively for many years, the inventor has developed a promoter capable of activating expression specifically in a floral organ tissue according to the invention and the application thereof.
SUMMARY OF THE INVENTION
[0008] Accordingly, one object of the invention is to provide a promoter capable of activating expression specifically in a floral organ tissue, wherein the sequence of said promoter is derived from the promoter PtACS2 (GeneBank accession number AF004663, SEQ ID No: 1) for gene of 1-aminocyclopropane-1-carboxylic acid synthase (ACC synthase) of Phalaenopsis True Lady. In the invention, the cDNA from ACC synthase gene PtACS2 of Phalaenopsis True Lady is used as a probe, a plaque hybridization reaction is carried out on the genomic DNA library of Phalaenopsis , and, after several purifications, a Phalaenopsis ACC synthase genomic clone is obtained. Nucleic acid sequencing shows a 2,968 bp local sequence (SEQ ID No: 2) ahead of the translation start site (gene code: ATG) of Phalaenopsis ACC synthase gene PtACS2. That sequence is used as the promoter of Phalaenopsis ACC synthase gene PtACS2.
[0009] In order to analyze whether said Phalaenopsis ACC synthase gene PtACS2 promoter (SEQ ID No: 2) exhibits tissue specificity, the sequence of that promoter is ligated to the 5′ end of the sequence of a reporter gene, β-glucuronidase (GUS) gene such that the promoter can act as the promoter of said reporter gene. Then, the assembly of the promoter and the reporter gene is constructed into an Agrobacterium transformation vector to form a plasmid pPtACS2-GUS. Thereafter, by using Agrobacterium transformation process, said plasmid pPtACS2-GUS is transformed into model plants, Arabidopsis thialana and Nicotiana tabacum L., respectively. The activating activity of said gene promoter is assayed then by means of histochemical staining of GUS. The result shows that said Phalaenopsis ACC synthase gene PtACS2 promoter (SEQ ID No: 2) enables the gene activated thereby to be expressed specifically in a floral organ tissue of a plant. Therefore, the activating ability of the Phalaenopsis ACC synthase gene PtACS2 promoter (SEQ ID No: 2) according to the invention exhibits extreme tissue specificity.
[0010] In addition to providing a promoter capable of activating expression specifically in a floral organ tissue, the invention provides further a gene expression cassette. Said gene expression cassette comprises: (1) the promoter sequence (SEQ ID No: 2) according to the invention, and (2) a polynucleotide with an open reading frame (ORF), namely, a target gene. Said polynucleotide is attached to the 3′ end of the inventive promoter. Said promoter can start the transcription of said polynucleotide in an organism having said gene expression cassette. In a preferred embodiment, said target gene is a reporter gene, β-glucuronidase (GUS) gene.
[0011] Furthermore, by constructing the inventive Phalaenopsis ACC synthase gene PtACS2 promoter (SEQ ID No: 2) into a commercial transformation vector such as, but not limited to: pBI101 (ClonTech), pBI121 (ClonTech), pBIN 19 (GenBank Accession No: U09365), pCAMBIA1301, pCAMBIA1305, pGREEN (GenBank Accession No: AJ007829), pGREEN II (GenBank Accession No: EF590266) (John Innes Centre, www.pGreen.ac.uk), pGreen0029 (John Innes Centre), or pCLEAN (John Innes Centre), a gene expression vector can be formed. Alternatively, a target gene can be inserted in said gene expression vector in a manner that, after attaching said target gene to the 3′ end of the inventive promoter, a gene expression cassette described above can be formed. Moreover, through a transformation process, the inventive promoter together with the target gene attached downstream to its 3′ end can be transformed into a plant of interest. Further, the genomic constitution of the transgenic plant can be altered such that the inventive promoter together with the target gene can activate effectively the expression of said target gene in the objective transgenic plant and its progeny as well.
[0012] In another aspect, the invention further provides a process for producing a transgenic plant or parts of organ, tissue or cell of the transgenic plant comprising the above-mentioned gene expression cassette; said process is composed of the following steps:
[0013] step 1: taking cells or tissues of an objective plant;
[0014] step 2: transforming a gene expression cassette containing the inventive promoter sequence (SEQ ID No: 2) into cells or tissues of the objective plant obtained in step 1 to give a transgenic plant cell or transgenic plant tissue; and
[0015] step 3: cultivating the transgenic plant cell or transgenic plant tissue obtained in step 2 to give a transgenic plant or part of organ, tissue or cell of said transgenic plant having gene expression cassette containing the inventive promoter sequence (SEQ ID No: 2);
[0016] wherein the transformation method described in step 2 includes, but not limited to, Agrobacterium mediating method, gene recombinant virus infection method, transposon vector transformation method, gene gun transformation method, electroporation, micro-injection method, pollen tube pathway, liposome-mediated transformation method, ultrasonic-mediated transformation method, silicon carbide fiber-mediated transformation, electrophoresis, laser microbeam, polyethylene glycol (PEG), calcium phosphate transformation, DEAE-dextran transformation and the like.
[0017] These features and advantages of the present invention will be fully understood and appreciated from the following detailed description of the accompanying Drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.
[0019] FIG. 1A is the restriction enzyme map of the genome of the inventive Phalaenopsis ACC synthase gene PtACS2.
[0020] FIG. 1B shows the construction strategy for the plasmid pPtACS2-GUS containing the inventive Phalaenopsis ACC synthase gene PtACS2 promoter.
[0021] FIG. 2 shows the construction strategy for Agrobacterium transformation vector pGKU.
[0022] FIG. 3 shows results of the expression analysis for reporter gene β-glucuronidase (GUS) at various tissue sites in the progeny of Arabidopsis thialana transformant containing PtACS2p::GUS-NOS gene expression cassette: FIG. 3A : root; FIG. 3B : stem; FIG. 3C : leaf; FIG. 3D : floral organ (including petal, calyx and stamen).
[0023] FIG. 4 shows results of the expression analysis for reporter gene β-glucuronidase (GUS) at various tissue sites in the progeny of Nicotiana tabacum L. transformant containing PtACS2p::GUS-NOS gene expression cassette: FIG. 4A : root; FIG. 4B : stem; FIG. 4C : leaf; FIG. 4D : floral organ (including petal, calyx and stamen).
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Example 1
Cloning of Phalaenopsis ACC Synthase Gene PtACS2 Promoter
1. The Sources of Phalaenopsis λEMBL3 Genomic Library
[0024] Phalaenopsis genomic library was prepared by extracting genomic DNA from leaves of a white with red lip Phalaenopsis True Lady, and then carrying out the construction of a genomic library through enzyme digestive replacement of DNA fragment by using bacteriophage λEMBL3 as the vector.
2. Preparation and Labeling of a Nucleic Acid Probe
[0025] A nucleic acid probe was prepared by using cDNA (with sequence as shown in SEQ ID No: 1) of Phalaenopsis ACC synthase gene PtACS2 (GeneBank accession number AF004663) as the template of the probe, carried out a process based on the principle of random primer labeling by means of Prime-a-gene kit (Stratagene). The total reaction volume was 50 μL, and the reaction mixture contained 1.2 μg/mL of a single-strand DNA fragment, 400 μg/mL of BSA, 20 μM dNTP (dAT P, dTTP, dGTP), 1× labeling buffer, 50 μCi [α- 32 P] dCTP, 5 units of Klenow DNA polymerase. It was allowed to react at 37° C. for more than 1 hour. Thereafter, the reaction was terminated by addition of 2 μL of 0.5 M EDTA-Na 2 (pH 8.0). Then, 8 μL of tracing dye (50% glycerol, 0.25% bromophenol blue) was added thereto. The reaction solution was passed through a Sephadex-G50 chromatographic column eluting with TE (pH 7.6), and fractions were collected in tubes. Then, the radioactivity of fractions thus collected was measured on a Liquid Scintillation Counter (Beckman 1801). Fractions collected from the first peak with strongest radioactivity were used as the probe.
[0000] 3. Screening of Phalaenopsis ACC Synthase from Genomic Library
[0026] Phalaenopsis genomic library was screened by means of plaque hybridization to give 1.5 million plaque forming units. At first, bacteriophages were diluted serially with SM (100 mL SM, containing 0.58 g NaCl, 0.2 g MgSO 4 .7H 2 O, 5 mL Tris-HCl and 0.01 g gelatin). Then, host cells ( Escherichia coli XL1-Blue MRA (P2)) was added thereto and incubated in a water bath at 37° C. for 15 minutes. Thereafter, it was mixed homogeneously with top agarose (each liter containing 5 g NaCl, 2 g MgSO 4 .7H 2 O, 5 g Bacto-Yeast extract, 10 g NZ amine A, 7 g Agarose, pH 7.5), applied over NZY solid culture medium (each liter containing 5 g NaCl, 2 g MgSO 4 .7H 2 O, 5 g yeast extract) and incubated at 37° C. for 8˜10 hours. After this time, the bacteriophages were transferred to nitrocellulose membrane. The membrane was treated successively in denaturing buffer (0.5 M NaOH, 1.5 M NaCl) for 2 minutes, neutral buffer (0.5 M Tris-HCl, 1.5 M NaCl, pH 7.5) for 5 minutes, and 2×SSPE (0.36 M NaCl, 20 mM NaH 2 PO 4 .H 2 O, 2 mM EDTA, pH 7.4) for 30 seconds. Then, after treated in a vacuum oven at 80° C. for 2 hours, the membrane was placed in 2×SSPE and 0.1% SDS solution, and was shaken at room temperature for 1 hour. Thereafter, it was placed in a pre-hybridizing solution (5×SSPE, 0.1% SDS, 5×BFP (0.1% BSA, 0.1% Ficoll, 0.1% Polyvinyl pyrrolidone), 30% Formamide, 500 μg/mL of denatured salmon sperm DNA) and allowed to react at 37° C. for more than 2 hours. After the pre-hybridizing reaction, the membrane was placed in a hybridizing solution (5×SSPE, 0.1% SDS, 1×BFP, 30% Formamide, 100 μg/mL of denatured salmon sperm DNA and denatured probe solution), and allowed to react at 37° C. for 16˜18 hours. Then, the membrane was treated twice in a washing solution 1 (5×SSPE, 0.1% SDS) at room temperature for 15 minutes, and then treated twice in a washing solution II (1×SSPE, 0.5% SDS) at 37° C. for 15 minutes. After these treatments, it exposed to X-ray film (Kodak XAR film) at −80° C. After development, bacteriophages containing target gene DNA could be detected from the X-ray film. The corresponding bacteriophage plaque was picked up into SM containing 0.03% chloroform and was shaken slightly for 1 hour. It was then stored at 4° C. After several purifications, a target clone λOTACS1 could be obtained.
4. Mass Replication of Bacteriophages
[0027] The bacteriophage liquor of the above-described objective clone λOTACS1 was placed over NZY solid culture medium and the bacteriophage liquor was gashed with a toothpick. 3 mL Top agar incorporated with host cell, E. coli XL1-Blue MRA (P2), was added and was cultured over NZY solid culture medium at 37° C. for 8 hours. On the next day, the single plaque agar lump on the gashed line was picked up with a capillary. The agar lump was spread and cultured over NZY solid culture medium at 37° C. for 7-11 hours. Then, the culture medium was transferred into a refrigerator at 4° C., where SM was added to dissolve out bacteriophages. The solution thus obtained was collected into a centrifuge tube. Chloroform was added up to 0.03%. The mixture was then centrifuged at 4° C. 7,000 rpm (Beckman J2-MC, JS-13.1) for 5 minutes, and was placed at 4° C. for future extraction of bacteriophage DNA.
5. Extraction of Bacteriophage DNA
[0028] Host cell E. coli XL1-Blue MRA (P2) was cultured and concentration of host cells in the culture suspension was adjusted to OD 600 of 0.5. This was placed in ice till used. Bacteriophages of the objective clone λOTACS1 thus mass replicated above were mixed with host cells (count ratio of bacteriophages:host cell=5:1) in 1 mL SM and 5 mL of 2.5 mM CaCl 2 . The resultant mixture was allowed to stand at room temperature for 15 minutes. After this time, it was treated at 37° C. for 45 minutes and was added then thereto 100 mL of 2×NZY liquid culture medium (0.4% MgSO 4 .7H 2 O, 2% NaCl, 1% bacto-yeast extract, 2% NZ amine, 0.2% casaimino acid, 5 mM MgSO 4 , 25 mM Tris-HCl, pH 7.5). The mixture was incubated at 37° C. 240 rpm for more than 8 hours. Then, 4.5 mL Chloroform was added, followed by incubation at 37° C. 240 rpm for 15 minutes. Thereafter, it was centrifuged at 4° C. 5,000 rpm (Beckman J2-MC, JS-13) for 20 minutes. The supernatant was poured in another centrifuge tube and 100 μL DNase I (1 mg/mL) and 100 μL RNaseA (10 mg/mL) was added thereto. The resultant mixture was treated at 37° C. 80 rpm for 45 minutes. Next, 33 mL of 4 M NaCl was added and placed in an ice-water bath for 1 hour. After adding 33 mL of 50% polyethylene glycol, it was treated at 4° C. for more than 4 hours, then centrifuged at 5,000 rpm for 20 minutes (Beckman J2-MC, JA-10). The supernatant was removed completely, and the pellet was suspended in 500 μL of PKB solution (10 mM NaCl, 10 mM Tris-HCl, pH 8.0, 10 mM EDTA, 0.1% SDS). To the suspension thus obtained, proteinase K (final 12.5 μg/mL) was added and allowed to react at 37° C. for 20 minutes. The upper layer was extracted with a mixed solvent of equal volume of phenol, PCI (phenol:chloroform:isoamyl alcohol=25:24:1) and CI (chloroform:isoamyl alcohol=24:1). Thereafter, 2-fold volume of 100% ethanol (−20° C.) was added and mixed homogeneously. DNA was picked up and rinsed by immersing in 70% ethanol and 100% ethanol. After being air-dried, it was re-dissolved in 100 μL TE (pH 7.5). Its DNA concentration was determined by OD 260 , and then stored at 4° C. till used for DNA sequencing.
6. DNA Sequencing
[0029] DNA of the objective clone λOTACS1 extracted as described above was subjected to DNA sequencing by means of an automatic nucleic acid sequencer ABI sequencer 377 to give the genomic sequence of Phalaenopsis ACC synthase gene PtACS2 and was analyzed with PC/Gene software package from IntelliGenetics Inc. The result was shown in FIG. 1A . As shown in FIG. 1A , Phalaenopsis ACC synthase gene PtACS2 contained four exons, and has its translation start site (gene code: ATG) located at 54˜56 nucleotides of the exon 1. Ahead of said translation start site of Phalaenopsis ACC synthase gene PtACS2 genomic clone λOTACS1, there was a 2,968 bp promoter region, with a sequence of said promoter region as shown in SEQ ID No: 2.
Example 2
Construction of a Vector Containing Phalaenopsis ACC Synthase Gene PtACS2 Promoter
[0030] The construction strategy of a vector containing Phalaenopsis ACC synthase gene PtACS2 promoter was shown in FIG. 1B . A 2,968 bp local sequence (SEQ ID No: 2) ahead of the translation start site of Phalaenopsis ACC synthase gene PtACS2 was used as the Phalaenopsis ACC synthase gene PtACS2 promoter (PtACS2p). Said promoter (PtACS2p) was constructed into the Agrobacterium transformation vector pGKU to replace the original CaMV 35S promoter (35Sp) in a manner that the 3′ end of the Phalaenopsis ACC synthase gene PtACS2 promoter (PtACS2p) sequence was linked to the 5′ end of the reporter gene β-glucuronidase (β-glucuronidase, GUS) gene sequence, so as to be used as the promoter for said reporter gene.
[0000] Step 1: Construction of Agrobacterium Transformation Vector pGKU
[0031] The construction strategy of Agrobacterium transformation vector pGKU was shown in FIG. 2 . A fragment (CaMV 35S::GUS-NOS) was taken from the CaMV 35S promoter (35Sp)-reporter gene (GUS)-terminator (NOS-ter) of a commercial vector pRT99GUS (Töpfer et al., 1988), and was constructed into a commercial transformation vector pGreen0029 (John Innes Centre) for Agrobacterium to give a transformation vector pGKU. The construction strategy involved the synthesis of a CaMV 35S promoter (35Sp) DNA fragment and a reporter gene (GUS)-terminator (NOS-ter) DNA fragment by means of polymerase chain reaction (PCR), respectively. Through the design of PCR primer, NcoI restriction site was created at the 3′ end of CaMV 35S promoter (35Sp) DNA fragment and the 5′ end of reporter gene (GUS)-terminator (NOS-ter) DNA fragment, respectively. Finally, these two PCR synthetic fragments were constructed into pGreen0029 to give Agrobacterium transformation vector pGKU.
[0000] Step 1.1: Obtaining CaMV 35S Promoter (35Sp) Fragment from a Commercial Vector pRT99GUS
[0032] The DNA of a commercial vector pRT99GUS was used as a template to carry out the amplification of DNA sequence of CaMV 35S promoter (35Sp) by PCR. Primers used in the PCR were as followed:
Forward Primer S5 (Containing the HindIII Restriction Site):
[0033]
[0000]
5′-TGCATGCATGC G-3′
(SEQ ID No: 3)
HindIII
Reverse Primer S3 (Containing the NcoI Restriction Site):
[0034]
[0000]
(SEQ ID No: 4)
5′-ATA CCCGGGGATCCTCTAGAGTCGAGGTCCT-3′
NcoI
[0035] Total volume of PCR reactant was 50 μl (consisting of: 1 μl genomic DNA, 10 μl of 5× Phusion HF buffer, 1 μl of 10 mM dNTP, 1 μl of 20 μM forward primer, 1 μl of 20 μM reverse primer, 35.5 μl sterile water, 0.5 μl Phusion DNA polymerase) and PCR conditions were: 98° C. for 30 seconds, then 35 cycles at 98° C. for 10 seconds, 60° C. 30 seconds, and 72° C. 60 seconds, and finally, 72° C. for 10 minutes for elongation. PCR product of 544 bp in length was synthesized. This PCR product was digested with restriction enzymes HindIII and NcoI and a DNA fragment (fragment S) of 470 bp in length was recovered, which was stored at 4° C. until used.
[0000] Step 1.2: Obtaining Reporter Gene (GUS)-Terminator (NOS-Ter) Fragment from a Commercial Vector pRT99GUS
[0036] Similarly, the DNA of a commercial vector pRT99GUS was used as the template in the PCR for the amplification of the DNA sequence of a reporter gene (GUS)-terminator (NOS-ter). Primers used in the PCR were as followed:
Forward Primer G5 (Containing NcoI Restriction Site):
[0037]
[0000]
5′-ATA TACGTCCTGTAG-3′
(SEQ ID No: 5)
NcoI
Reverse Primer G3 (Containing HindIII Restriction Site):
[0038]
[0000]
5′-ACGGCCAGTGCC GCAT-3′
(SEQ ID No: 6)
HindIII
[0039] Total volume of PCR reactants was 50 μl (consisting of: 1 μl genomic DNA, 10 μl of 5× Phusion HF buffer, 1 μl of 10 mM dNTP, 1 μl of 20 μM forward primer, 1 μl of 20 μM reverse primer, 35.5 μl sterile water, 0.5 μl Phusion DNA polymerase) and PCR conditions were: 98° C. 30 seconds, then 35 cycles at 98° C. for 10 seconds, 60° C. 30 seconds, and 72° C. 60 seconds, and finally, 72° C. 10 minutes for elongation. A PCR product of 2,108 bp in length was synthesized. The PCR product was digested with HindIII and NcoI restriction enzymes and a DNA fragment (fragment G) of 2,093 bp in length was recovered, which was stored at 4° C. till used.
Step 1.3: Ligation of DNA
[0040] A commercial vector pGreen0029 was digested with HindIII restriction enzyme to recover a DNA fragment (fragment P) of 4,632 bp. This fragment was subjected to DNA ligation with fragment S and fragment G obtained in the above steps 1.1 and 1.2, respectively, to give transformation vector pGKU. As shown in FIG. 2 , in addition to pGreen feature, transformation vector pGKU contained: CaMV 35S promoter (35Sp)-reporter gene (GUS)-terminator (NOS-ter) DNA fragment of a commercial vector pRT99GUS, and also HindIII and PstI restriction sites at the 5′ end of CaMV 35S promoter (35Sp) as well as NcoI restriction site at the 3′ end of CaMV 35S promoter (35Sp), such that Agrobacterium transformation vector pGKU could replace CaMV 35S promoter (35Sp) with other promoter sequence into the promoter of the reporter gene (GUS) by using restriction enzymes such as HindIII, PstI, NcoI and the like.
Step 2: Obtaining the Sequence of Phalaenopsis ACC Synthase Gene PtACS2 Promoter (PtACS2p)
[0041] A 2,968 bp local sequence (SEQ ID No: 2) ahead of the translation start site of Phalaenopsis ACC synthase gene PtACS2 was used as the Phalaenopsis ACC synthase gene PtACS2 promoter PtACS2p. As shown in FIG. 1B , a DNA fragment (fragment Ps) of 2,484 bp in length at the 5′ end and a DNA fragment (fragment Us) of 495 bp in length at the 3′ end of Phalaenopsis ACC synthase gene PtACS2 promoter (PtACS2p) were obtained through PCR. Further, by means of the design of PCR primers, a NcoI restriction site was incorporated at the 3′ end of the fragment Us for subsequent construction.
[0000] Step 2.1: Obtaining a DNA Fragment (Fragment Ps) of 2,484 bp in Length from the 5′ End of Phalaenopsis ACC Synthase Gene PtACS2 Promoter (PtACS2p)
[0042] Genomic DNA extracted from the leaf of white with red lip Phalaenopsis True Lady was used as the template to carry out PCR for the amplification of fragment Ps DNA sequence. Primers used in PCR were as followed:
Forward Primer ACS5-1 (Containing PstI Restriction Site):
[0043]
[0000]
5′-ACA GTCAACGGATCAA-3′
(SEQ ID No: 7)
PstI
Reverse Primer ACS3-1 (Containing BglII Restriction Site):
[0044]
[0000]
5′-TAC AGCACTCAA-3′
(SEQ ID No: 8)
BglII
[0045] Total volume of PCR was 50 μl (consisting of: 1 μl genomic DNA, 10 μl of 5× Phusion HF buffer, 1 μl of 10 mM dNTP, 1 μl of 20 μM forward primer, 1 μl of 20 μM reverse primer, 35.5 μl sterile water, 0.5 μl Phusion DNA polymerase). PCR conditions were: 98° C. for 30 seconds, 35 cycles of 98° C. for 10 seconds, 60° C. for 30 seconds, and 72° C. for 60 seconds, and finally, 72° C. for 10 minutes for elongation. A PCR product of 2,490 bp in length was synthesized. The PCR product was digested with PstI/BglII restriction enzyme. A DNA fragment (fragment Ps) of 2,484 bp in length was obtained and was stored at 4° C. till used.
[0000] Step 2.2: Obtaining DNA Fragment (Fragment Us) of 495 bp in Length from the 3′ End of Phalaenopsis ACC Synthase Gene PtACS2 Promoter (PtACS2p)
[0046] In a similar manner, genomic DNA extracted from the leaf of white with red lip Phalaenopsis True Lady was used as the template to carry out PCR for the amplification of fragment Us DNA sequence. Primers used in PCR were as followed:
Forward Primer ACS5-2 (Containing BglII Restriction Site):
[0047]
[0000]
5′-GAGTGCT GTAAA-3′
(SEQ ID No: 9)
BglII
Reverse Primer ACS3-2 (Containing NcoI Restriction Site):
[0048]
[0000]
5′-TTTAG ATTTTAATTAGTAC-3′
(SEQ ID No: 10)
NcoI
[0049] Total volume of PCR was 50 μl (consisting of: 1 μl genomic DNA, 10 μl of 5× Phusion HF buffer, 1 μl of 10 mM dNTP, 1 μl of 20 μM forward primer, 1 μl of 20 μM reverse primer, 35.5 μl sterile water, 0.5 μl Phusion DNA polymerase). PCR conditions were: 98° C. for 30 seconds, then 35 cycles of 98° C. for 10 seconds, 60° C. for 30 seconds, and 72° C. for 60 seconds, and finally, 72° C. for 10 minutes for elongation. PCR product of 505 bp in length was synthesized. The PCR product was digested with BglII and NcoI restriction enzymes. A DNA fragment (fragment Us) of 495 bp in length was recovered and stored at 4° C. till used.
Step 3: DNA Ligation
[0050] Agrobacterium transformation vector pGKU obtained in step 1 was digested with PstI/NcoI double restriction enzymes. The digested vector pGKU was recovered, which was then subjected to a DNA ligation with fragment Ps and fragment Us obtained in step 2.1 and step 2.2, respectively, to give a plasmid pPtACS2-GUS containing promoter sequence (SEQ ID No: 2) of Phalaenopsis ACC synthase gene PtACS2. In said plasmid pPtACS2-GUS, a DNA sequence of a reporter gene β-glucuronidase (GUS) (PtACS2p::GUS-NOS) was linked at the 3′ end of Phalaenopsis ACC synthase gene PtACS2 promoter. Consequently, after transforming said plasmid pPtACS2-GUS in a plant through Agrobacterium tumefaciens infiltration, analysis for the mode to start the expression of the reporter gene β-glucuronidase (GUS) gene by the Phalaenopsis ACC synthase gene PtACS2 promoter could be carried out.
Example 3
Transformation of Arabidopsis thialana by Agrobacterium -Mediated Transformation Method
[0051] By using a model plant Arabidopsis thialana ecotype Columbia as starting material and employing Agrobacterium transformation, plasmid pPtACS2-GUS obtained in Example 2 was transformed into Arabidopsis thialana to change the genomic constitution of the transgenic plant such that Phalaenopsis ACC synthase gene PtACS2 promoter could start effectively the expression of the reporter gene GUS in the objective transgenic plant and also in progeny thereof. The expression site of the reporter gene GUS in Arabidopsis thialana transformant was analyzed by means of histochemical staining of GUS to detect whether Phalaenopsis ACC synthase gene PtACS2 promoter exhibited tissue specificity.
1. Preparation of Agrobacterium Liquor
[0052] The Agrobacterium tumefaciens EHA105 was inoculated in YEB solid medium (5 mg/L yeast extract, 10 g/L peptone, 10 g/L NaCl, 15 g/L Agar, pH 7.2) containing 100 μg/mL Rifamycin SV. After culturing at 28° C. for 2 days, a single colony was picked up and inoculated in 20 mL YEB liquid culture medium containing 100 μg/mL Rifamycin SV. The mixture was cultured at 28° C. under shaking at 240 rpm for 1 day. To 5 mL bacterial suspension thus cultured for 1 day, 200 mL YEB liquid medium containing 100 mg/L Rifamycin SV was added, and cultured at 28° C. under shaking at 240 rpm to OD 600 value of 0.5-0.8. The resulting suspension was centrifuged at 4° C., 4,200 rpm for 20 minutes (Beckman J2-MC, JA-10). After removing supernatant, the bacteria pellet was re-suspended in 200 mL pre-chilled sterile water. The centrifuging step described above was repeated once, the pellet was suspended in 100 mL sterile water, and then centrifuged again. The bacteria pellet was suspended in 50 mL sterile water, and one final centrifuging was carried out. The bacteria pellet was suspended in 2 mL pre-chilled 10% (v/v) glycerol, and dispended into units of 50 μl, which were stored at −80° C. till used.
2. Transformation of Agrobacterium
[0053] The frozen Agrobacterium cell described above was thawed, and 100 ng of the plasmid pPtACS2-GUS DNA obtained in Example 2 and 100 ng of a helper plasmid DNA (Soup DNA) were added thereto. In water bath, the plasmid DNA and Agrobacterium were mixed homogeneously, transferred into an electroporation cuvette, and subjected to electroporation under conditions of 1.44 KV amplitude, 99 μsec pulse width, for 10 pulses. After completion of electroporation, 1 mL 28° C. YEB liquid culture medium was added, and all of the liquid was drawn into a small test tube, followed by incubating at 28° C. for 1 hour. An appropriate amount of bacterial suspension was taken out, applied over a medium containing antibiotics and cultured at 28° C. for two days.
[0000] 3. Mini-Preparation of Agrobacterium Plasmid after Transformation
[0054] A single colony of Agrobacterium transformant containing plasmid pPtACS2-GUS prepared in Example 2 was used to inoculate in 50 mL YEB liquid culture medium incorporated with 100 μg/mL of Rifamycin SV and 50 μg/mL of Kanamycin, and was incubated at 28° C. by shaking at 240 rpm for 2 days. The whole bacteria suspension was transferred in a 500 mL centrifuge tube, chilled over ice for 5-15 minutes, and then centrifuged at 4° C., 3,700 rpm for 10 minutes (Beckman J2-MC, JS-13.1). The supernatant was discarded, and bacteria pellet was suspended in 1 mL pre-chilled TE (pH 8.0). The resulting suspension was transferred in a 1.5 mL micro-centrifuge tube, and centrifuged at room temperature, at 14,000 rpm for 1 minute. The supernatant was discarded, 200 μL lysozyme [25 mg/mL in GTE (25 mM Tris-HCl, pH 8.0, 10 mM Na 2 EDTA, 50 mM glucose)] was added. After mixed homogeneously by shaking at room temperature for 3-5 minutes, fresh 400 μL NaOH/SDS (0.2 N NaOH, 1% SDS) was added, mixed and placed on ice for 7 minutes. Then, 300 μL of 3 M potassium acetate was added, mixed homogeneously and placed on ice for 12 minutes. Thereafter, the suspension was centrifuged at 4° C., 13,200 rpm for 5 minutes. 800 μL of the supernatant was drawn into a micro-centrifuge tube containing 500 μL ice-cold isopropanol, and mixed homogeneously. After centrifuged at 4° C., 13,200 rpm for 10 minutes, the supernatant was discarded, and the pellet was suspended in 135 μL TE (pH 8.0). Next, 100 μL of phenol/chloroform/IAA, and 100 μL CI was added, and centrifuged at 14,000 rpm for 2 minutes. The upper clear solution was drawn into a new micro-centrifuge tube for purifying DNA. 100 μL of 4 M NH 4 OAc and 400 μL of 100% ethanol were added to precipitate DNA. Finally, the remaining salt was washed off with 200 μL of 70% ethanol, and 200 μL of 100% ethanol, followed by dissolving in 10 μL sterile water containing 0.1 mg/mL RNaseA. Then, the resulting solution was subjected to restriction enzyme digestion and analysis to check if successfully cloned.
[0000] 4. Growth of Arabidopsis thialana
[0055] Seeds of Arabidopsis thialana were sowed in a medium consisting of peat mosses:vermiculite #3:Perlite # 3 in a ratio of 8:1:1, and was covered with a mesh. Cultivation was carried out in a growth box at 23° C., 16 hours light/8 hours dark, and 75% humidity. As the second pair of leaves was grown, 1,000 ppm HYPONeX2 (The HYPONeX Corp., OH, USA) was applied once every two weeks. After about 3-4 weeks, the plant was pruned. As the rachis had grown to a length of about 7-15 cm after 2 or 3 pruning operations, the plant was subjected to transformation.
[0000] 5. Transformation of Arabidopsis thialana
[0056] Three days prior to transformation of Arabidopsis thialana, Agrobacterium that had been transfected and hence contained plasmid pPtACS2-GUS prepared in Example 2 was inoculated in 10 mL YEB culture medium containing 100 μg/mL Rifamycin SV and 50 μg/mL Kanamycin. The resulting suspension was cultured at 28° C. by shaking at 240 rpm for 2 days. To the 5 mL of the bacteria suspension thus obtained, 500 mL YEB liquid culture medium containing 100 μg/mL Rifamycin SV and 50 μg/mL Kanamycin was added. After incubation at 28° C. shaking at 240 rpm for 1˜2 day, the suspension was centrifuged at 4° C., 6,000 rpm for 10 minutes (Beckman J2-MC, JA-10). The supernatant was discarded and the bacteria pellet was suspended in 200 mL infiltration medium (½ MS basal medium, 5% sucrose, 2 mg/mL BA, 0.01% Silwet L-77, pH 5.7 with 1 M KOH), which was stored on ice till used. On the day of transformation, blossoming floweret and siliques were removed. The plant was placed upside down in a 250-mL baker containing Agrobacterium liquor in a manner that all flowerets were soaked therein for several seconds and this procedure was repeated 3 times over a period of 20 seconds. Alternatively, the infiltration could be carried out by suction at 40 mmHg vacuum for Arabidopsis thialana Columbia was then removed and kept wet for 1 minute. The plant thus treated was grown under normal conditions. Upon siliques being dehiscent, they were bagged. Three weeks after being bagged, its seeds were harvested.
6. Screening of Transformant
[0057] Appropriate amount of seeds of Arabidopsis thialana Columbia thus harvested was weighed in a 15-mL centrifuge tube, soaked with fresh water for 30 minutes, followed by rinsing 2-3 times with sterile water and then treated with 10 mL of 20% bleach containing 0.05% Tween-20 by shaking vigorously for 15 minutes. The upper liquid layer was aspired off, and seeds were washed 3 times with sterile water, followed by adding sterile water 2-fold the volume of the seeds. Seeds were suspension sowed in a screening medium (½ MS medium, 1% sucrose, 50 μg/mL Kanamycin, 50 μg/mL Cefotaxime, 0.7% agar, pH 5.7).
7. Histochemical Staining of GUS
[0058] Roots, stems, leaves, and inflorescences were clipped form Arabidopsis thialana transformant and were soaked first in a pre-treatment buffer [50 mM Na 3 PO 4 (pH6.8), 1% TritonX-100] at 37° C. for 2 hours, followed by 2-3 times rinsed with a buffer solution (50 mM Na 3 PO 4 , pH 6.8) containing no Triton X-100. Then, a buffer solution (1 mM X-Gluc, dissolved in 50 mM Na 3 PO 4 , pH 6.8) containing X-Gluc (5-Bromo-4-chloro-3-indoxyl-beta-D-glucuronic acid) was added. The resulting mixture was treated at 25 inches-Hg vacuum for 5 minutes. Five minutes after being returned to atmospheric pressure, the procedure was repeated once more. Thereafter, the mixture was allowed to react at 37° C. for 2 days. Finally, 70% ethanol was added to terminate the enzymatic reaction and effected tissue discoloration. The color presentation thereof was observed under a microscope.
[0059] Results of GUS activity analysis were shown in FIG. 3 . As shown in FIG. 3 , reporter gene GUS activated by Phalaenopsis ACC synthase gene PtACS2 promoter demonstrated its expression only at petal, calyx and stamen of the floral organ in Arabidopsis thialana transgenic plant (as shown in FIG. 3D ), while no GUS activity could be detected at the root, stem and leaf of Arabidopsis thialana transgenic plant (as shown in FIG. 3 A-C). It was shown from the result of GUS activity analysis that Phalaenopsis ACC synthase gene PtACS2 promoter exhibited expression specificity at floral organ tissues, and had significant activation ability.
Example 4
Transformation of Nicotiana tabacum L. by Employing Agrobacterium -Mediated Transformation Method
[0060] In this example, Nicotiana tabacum L. ( Nicotiana tabacum L. cv Wisc. 38) was used as the starting material and was subjected to a similar Agrobacterium transformation process to transfer plasmid pPtACS2-GUS prepared in Example 2 into Nicotiana tabacum L., while changing the genomic constitution of the transgenic plant such that Phalaenopsis ACC synthase gene PtACS2 promoter could activate effectively the expression of reporter gene GUS in the objective transgenic plant and progeny thereof. Furthermore, expression sites of reporter gene GUS at Nicotiana tabacum L. transgenic plant was analyzed by histochemical staining of GUS to detect whether Phalaenopsis ACC synthase gene PtACS2 promoter possessed tissue specificity in Nicotiana tabacum L. transgenic plant.
1. Preparation of Agrobacterium Liquor
[0061] This step was carried out as described in Example 3.
2. Transformation of Agrobacterium
[0062] This step was carried out as described in Example 3.
[0000] 3. Mini-Preparation of Agrobacterium Plasmid after Transformation
[0063] This step was carried out as described in Example 3.
[0000] 4. Transformation and Screening of Nicotiana tabacum L.
[0064] Leaves of aseptic sowed Nicotiana tabacum L. ( Nicotiana tabacum L. cv Wisc. 38) plant was cut into squares of 1.5 cm×1.5 cm, which were placed over N01B1 solid culture medium (MS, 0.1 mg/L 1-naphthyl acetic acid, 1 mg/L BA, 3% sucrose, pH 5.7, 0.7% agar), and incubated at 25° C., in 16-hour light for 1 day. Thereafter, these leaf discs were immersed in the bacterial liquor for 3-5 minutes, and then placed over N01B1 solid culture medium. After being incubated at 25° C. in 16-hour light for 3 days, these leaf discs were rinsed by dipping in 20 mL N01B1 liquid culture medium containing 250 mg/L cefotaxime for 1 minute. Then, they were transferred onto N01B1 solid culture medium containing 250 mg/L Cefotaxime and 100 mg/L Kanamycin and were selected at 25° C. in 16-hour light for about 3 weeks. As adventitious shoots had shot from these leaf discs, they were transferred onto N01B1 solid culture medium containing 250 mg/l Cefotaxime and 200 mg/l Kanamycin, and were selected at 25° C. of 16-hour light. When shoots had grown to be longer than 1 cm, non-etiolated buds could be cut and cottage in MS solid culture medium containing 250 mg/L Cefotaxime and 200 mg/L Kanamycin and incubated at 25° C. in 16-hour light to permit root formation. Plant thereof was subjected to GUS activity assay.
5. Histochemical Staining of GUS
[0065] Roots, stem, leaves, and inflorescences were clipped form Nicotiana tabacum L. transformant, and were subjected to histochemical staining of GUS, respectively, following same process as described in Example 3.
[0066] Results of GUS activity analysis were shown as in FIG. 4 . Reporter gene GUS activated by Phalaenopsis ACC synthase gene PtACS2 promoter could be expressed only at the petal, calyx and stamen in the floral organ of Nicotiana tabacum L. transformant ( FIG. 4D ), while no GUS activity could be detected at the root, stem and leaf of Nicotiana tabacum L. transformant ( FIG. 4 A-C). From the results of GUS activity analysis for Arabidopsis thialana and Nicotiana tabacum L. transformants, it was demonstrated that Phalaenopsis ACC synthase gene PtACS2 promoter had indeed a characteristic of activating expression specifically in floral organ, and possessed significant activation ability.
[0067] Many changes and modifications in the above described embodiment of the invention can, of course, be carried out without departing from the scope thereof. Accordingly, to promote the progress in science and the useful arts, the invention is disclosed and is intended to be limited only by the scope of the appended claims.
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A flower tissue-specific promoter, and uses thereof, is the promoter for Phalaenopsis 1-aminocyclopropane-1-carboxylic acid synthase, ACC synthase gene PtACS2, and has a sequence as shown in SEQ ID No: 2. The invention further provides a gene expression cassette, which is composed of a promoter having a DNA sequence as SEQ ID No: 2, and a polynucleotide with an open reading frame linked to the 3′ end of said promoter, wherein said promoter can activate transcription of said polynucleotide in an organism containing said gene expression cassette. The invention provides furthermore a gene expression vector, which is composed of a promoter having a DNA sequence as SEQ ID No: 2. The invention provides further a method for producing a transgenic plant or parts of organ, tissue or cell of the transgenic plant that contain a gene expression cassette described above.
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CROSS-REFERNECE TO RELATED APPLICATION
This application is the U.S. National Phase application of PCT Internantional Application No.PCT/GB2009/051686, filed Dec. 10, 2009, and claims priority of British Patent Application No. 0822479.2, filed Dec. 10, 2008, the disclosures of both of which are incorporated herein by reference in their entirety for all purposes.
FIELD OF THE INVENTION
The present invention concerns improvements in catalysts, and more especially concerns supported silver oxide catalysts. Such catalysts may be used in the destruction of excess sterilants such as ozone or hydrogen peroxide.
BACKGROUND TO THE INVENTION
The use of a sterilant such as ozone or hydrogen peroxide is established for removing many bacteria and other pathogenic microorganisms from an enclosed area environment. Unfortunately, such sterilants are also toxic or hazardous to higher life forms such as humans or domesticated animals, and great care has to be taken to reduce the concentration of the sterilant to safe levels before allowing access.
Contaminants to be removed may be of biological or of synthetic origin, including bacterial, viral, and other pathogens, or synthetic toxic agents such as compounds that interfere with biological processes. The environments may include areas where plants are grown such as greenhouses, food processing areas such as kitchens, hotel rooms, conference centres, isolation rooms and other areas in hospitals etc that may have been contaminated as well as rooms in dwellings and ambulances etc, and places where animals are kept such as on farms and zoos, especially quarantine areas, but including henhouses or other areas of high concentrations of animals.
Decontamination equipment to be used may be fixed or portable with electrical power from the mains supply, or from internal rechargeable batteries that are periodically recharged.
For ease of description, the following description concentrates on the use of ozone as the sterilant.
It is generally known that it may be advantageous to humidify the atmosphere prior to or during sterilisation. Humidification of the air may be achieved by spaying a mist of water droplets from a suitable nozzle(s), or by passing steam into the environment that would normally be at a temperature between 10° C. and 45° C., before, at the same time, or subsequent to introducing ozone into the environment. It is believed that the higher the humidity the better—the water enhances the effectiveness of the ozone, perhaps through formation of hydroxyl radicals that are especially potent oxidants, but this may depend on the actual prevailing conditions. At present, it is envisaged that humidification to greater than about 70% relative humidity will be preferred, but other humidity levels may be used.
As indicated above, the ozone may react with water vapour to form hydroxyl radicals, a particularly powerful oxidant, and it is probable that it is hydroxyl radicals that are the highly active agent. Combination of hydroxyl radicals in three body reactions would lead to formation of hydrogen peroxide that also has powerful antiseptic properties.
Ozone may be produced from a suitable ozone generator such as irradiating oxygen with ultraviolet irradiation or electrical techniques such as those involving corona discharge or plasma formation. Preferably the source of oxygen contains only limited amounts of nitrogen (eg less than 15%) to minimise the formation of undesirable nitrogen oxides. Although air may be used as the source of ozone, it is preferred to use pure oxygen or oxygen-enriched air.
The amount of ozone in the environment should be maintained at a level and time sufficient to destroy all of the contaminants present. Typical values are at least 10-50 ppm ozone and preferably 20-40 ppm ozone for 20-120 minutes, and preferably 30-60 minutes.
After the ozone and its derivatives have decontaminated the environment, the atmosphere of the environment is suitably circulated using a fan through a filter to remove particulate matter that might be present, and then over a catalyst to convert remaining ozone and its derivatives, such as hydrogen peroxide, to oxygen, or oxygen and water, so that the environment is safe for human or animal occupation.
The procedure described above may be accomplished using a computer-controlled system—for maintaining humidification, ozone levels for predetermined periods, and thereafter switching these off, and generating a flow of the atmosphere through a special catalyst to reduce the ozone to a safe level. Sensors provide inputs for this control, and predictive computer models enable reliable estimates to be made of the times needed for decontamination and the times needed to reduce the ozone to safe levels.
The prior art indicates active ozone decomposition catalysts include formulations containing metal components such as platinum or oxides such as those of manganese and other transition metal elements. Surprisingly, we have found platinum catalysts do not work well in this application involving high ozone levels and high humidity levels at ambient temperatures. Moderately good initial performance was observed but deactivation was very rapid. This may be due to strong adsorption of water and/or oxygen species on the active sites, and highlights the fact that this ozone-destruction application is very demanding. Highly-loaded MnO 2 catalysts had good initial activity, and while initially better than platinum, they quickly deactivated in use. We found removal of adsorbed species by vacuum oven treatment overnight at 150° C. restored a portion of the lost activity, but the combination of rapid deactivation and slow regeneration clearly means that this catalyst is certainly not a practical solution.
Some prior art suggests silver oxide/MnO 2 catalysts can have very good ozone decomposition activity. Silver oxide/MnO 2 catalysts were prepared and tested, but again they deactivated quickly under the unusual conditions of very high humidity and very high ozone concentrations at low temperature. It was thought humidity in particular was responsible for catalyst deactivation, and there was some experimental evidence to support this.
SUMMARY OF THE INVENTION
We have found that the presence of low levels of promoters has a major influence on catalytic performance of silver oxide catalysts in the present application. Through an optimisation process, it was discovered that silver oxide catalyst formulations containing alumina had relatively poor initial performance and after only a little use they lost considerable activity. Silver oxide with silica performed better, but silver oxide with silica and titania performed surprisingly well and surprisingly maintained this performance over extended duty cycles. It appears that silver oxide with titania has improved activity compared to silica/titania supports.
Accordingly, in a first aspect the present invention provides a catalyst for the destruction of ozone or other sterilant, comprising silver oxide, titania and optionally MnO 2 in an amount of up to 10% by weight of the catalyst.
In a second aspect, the present invention provides a method for removal of ozone or other sterilant from an atmosphere, comprising passing the atmosphere over a catalyst comprising silver oxide, titania and optionally MnO 2 in an amount of up to 10% by weight of the catalyst.
In a third aspect, the present invention provides a method of sterilising an enclosed space, comprising humidifying the atmosphere in the space and subsequently or simultaneously supplying an amount of ozone or other sterilant that achieves sterilisation in a predetermined period, then subsequently catalytically destroying the sterilant by passing the atmosphere over a catalyst comprising silver oxide, titania and optionally MnO 2 in an amount of up to 10% by weight of the catalyst.
DETAILED DESCRIPTION OF THE INVENTION
As noted above, the catalyst comprises silver oxide and titania but may also include small amounts of manganese dioxide. If manganese dioxide is present, it will not amount to more than 10% by weight of the catalyst. The catalyst may also include small amounts of silica, typically up to 15% by weight of the catalyst.
The proportion of silver oxide to titania and other oxides if present may be determined by conventional optimisation techniques but preferably the catalyst comprises at least 60% by weight of silver oxide, more preferably at least 70%, even more preferably at least 80% by weight of silver oxide.
The catalyst may be prepared using known technology and may be supported on conventional honeycomb monoliths having parallel channels, of the flow-through type, made from for example, ceramic or suitable stainless steel materials. The coating of supports using washcoats comprising the catalytically active component(s) and particulate supports is well established. In our preliminary tests on flow-through ceramic honeycomb supports, washcoat loadings of about 1.5 to 2.5 g/cu in have been used. Specific catalyst manufacturing techniques and washcoat/catalyst loadings may be optimised for particular applications in conventional manner.
With supported catalysts, low pressure-drop is important because of fan size limitations in practical application, especially with portable equipment. The flow through catalyst is normally housed in a metal (e.g. stainless steel) cylinder retained with a ceramic mat material, and having suitable coupling devices at its ends. Such arrangements are well known for vehicle catalytic converters.
The catalyst may be supported on a wall-flow filter in which alternate channel ends are plugged so forcing the gas to flow through the filter walls. The catalyst may be deposited on and/or in the filter walls thereby making more effective use of the catalyst at the expensive of increased backpressure. Foamed or pellet catalyst types can also be used in a suitable container preferable made from stainless steel or other ozone resistant material. Alternative supports such as high surface area sintered metal monoliths, metal devices known as static mixers, and partial filter constructions, may be used if appropriate.
Having a small amount of silica present as a binder in a washcoat is generally expected to improve washcoat adhesion to flow-through or filter-type supports, although we have not encountered adhesion problems with any of the catalysts we have prepared.
Silver containing catalysts can be susceptible to poisoning, especially at low temperature, particularly by sulphur compounds in either low or high oxidation state eg H 2 S and SO 2 . Because of the very large volumes of air passed over these catalysts in a working system, even small amounts of poison can rapidly cause at least some deactivation. It is therefore proposed that catalyst life is extended by protecting it with an upstream small volume of guard material that has a high affinity for poisons. Such guard material may be two separate layers or mixtures of high surface area zinc oxide (for H 2 S) and a form of alkalised high surface area material, such as alkalised alumina, to capture halides. The guard materials could be in the form of pellets or other solid form in a suitable container or alternatively coated onto a flow-through ceramic or metal monolithic honeycomb.
Our working examples described herein all use single catalyst supports 10.5 inch diameter and 6 inches long (approx 26.67 cm by 15.24 cm) (400 cpsi, 6 mil channel walls)—but this was for convenience and it is expected that other catalyst supports will be effective. Multiple smaller catalysts in parallel could provide greater flexibility, for example each catalyst could be fitted with its own fan and switching these on sequentially saves the cost of having soft start motor procedures etc. Other standard diameters of catalyst supports as well as oval shapes may be considered. As suggested each might have their own fan—this could provide greater flexibility for air flow directions etc as well as being more economic.
Indications are that the catalysts of the invention are effective over higher space velocity ranges than are commonly used, meaning that an enclosed space may be made safe more quickly. Conventional air flow rates with existing commercial equipment are in the range 650-750 m 3 /hr, equivalent to catalyst space velocities of 77-89×10 3 hr −1 . Our initial tests varied air flow rates from 400 to 1800 m 3 /hr, corresponding to catalyst space velocities of 47 to 213×10 3 hr −1 . Ozone levels in the rooms used in the tests fell more rapidly, in proportion, with increasing space velocity.
Further research work has established that operation of the catalysts of the invention at relatively low temperatures and relatively high humidities causes the formation of silver species having an oxidation state greater than one. This has been confirmed by X-ray diffraction studies. A reduction of the used catalyst with hydrogen in nitrogen at room temperature did reduce the higher oxidation state material, but the amount of Ag I oxide did not increase, and the activity was not restored.
We have now discovered that higher oxidation state silver material in used catalyst can be effectively regenerated by heat treatment in air at moderate temperatures. For example, heating in air at 150° C. converted all or substantially all of the higher oxidation state material into the active Ag I oxide form. The catalyst may be regenerated in situ or in a dedicated apparatus.
Deactivation could be avoided by operating the catalyst at higher temperatures, e.g. at 200° C., but this is not generally practicable when decontaminating a room in a hospital, for example.
Accordingly, it is preferred to incorporate an electric heater upstream of the catalyst, which may be periodically energised to increase the temperature of the air flowing over the catalyst while reducing the flow rate. Suitable temperatures for regeneration are in the range 130-250° C., for a period of from 5 mins to 10 hours, conveniently for 15 mins to 5 hours. An advantageous regeneration regime could be to regenerate the catalyst relatively frequently for short periods, so that the catalyst maintains its performance over extended periods of time.
The invention will now be further illustrated by reference to the following examples.
CATALYST EXAMPLES
Preparation of Catalyst A. Pt/Al 2 O 3 (Comparative)
Dispersible alumina (1250 g) was dispersed in deionised water (3.5 litres) adjusted to pH 4 by addition of dilute nitric acid by stirring with a high sheer mixer. The dispersed mixture was ball milled using ceria/zirconia balls for 30 minutes to give a d 50 particle size of less than 5 microns, then hydroxyethylcellulose (Natrosol from Aqualon) (6.5 g) was added during continued stirring to give a coating mixture that was easily applied to a cordierite monolithic honeycomb 10.5 inches diameter 6 inches high having 400 square channels per square inch with wall thickness of 6/1000 inch. Excess washcoat was removed with a high pressure air gun before drying in flowing air at 90° C. for 45 minutes. The washcoated monolithic honeycomb was calcined in air at 500° C. for 1 hour after which the weight of alumina on the monolithic honeycomb was 1145 g. The calcined honeycomb was impregnated with an aqueous solution containing platinum nitrate (9.6 g platinum/litre) and citric acid (100 g/litre), dried in an air flow at 90° C. before it was calcined at 500° C. for 2 hours. The coated monolith contained 12.0 g platinum.
Preparation of Catalyst D MnO 2 /Al 2 O 3 (Comparative)
Manganese dioxide was prepared by mixing hot (65° C.) aqueous solutions of KMnO 4 (210 g in 4 litres of water) and MnSO 4 (300 g in 6 litres of water) the resulting dark brown precipitate that formed was stirred at 65° C. for a further 3 hours. The precipitate was then filtered off, washed with warm deionised water (3×1 litre), and dried in an oven overnight at 110° C. to give an active form of MnO 2 (245 g). This preparation was repeated as necessary to provide the amounts of MnO 2 required. Subsequently it was found MnO 2 purchased from Alfa Aesar as activated manganese(IV) oxide could be substituted with similar results. To deionised water (1.2 litre) was added with stirring in a high shear mixer, MnO 2 (900 g) and dispersible Al 2 O 3 (100 g) to give a well mixed uniform slurry. This was then ball milled using ceria/zirconia balls for 3 hours to give a d 50 particle size of less than 5 microns. Deionised water was then added and hydroxyethylcellulose (Natrosol from Aqualon) (20.2 g) to form a coating mixture that could easily be applied to a cordierite honeycomb 10.5 inches diameter 6 inches high having 400 square channels per square inch with wall thickness of 6/1000 inch. Excess washcoat was removed by a high pressure air gun, and after drying in a flow of air at 90° C. for 1 hour the resulting coated monolith had 901 g of washcoat.
Preparation of Catalyst E MnO 2 /Al 2 O 3 (Comparative)
Manganese dioxide purchased from Alfa Aesar as activated manganese(IV) oxide (1039 g) was added to deionised water (1.2 litre) with stirring in a high shear mixer, and dispersible Al 2 O 3 (104 g) to give a well mixed uniform slurry. This was then ball milled using ceria/zirconia balls for 3 hours to give a d 50 particle size of less than 5 microns. Deionised water was then added and hydroxyethylcellulose (Natrosol from Aqualon) (6.7 g) to form a coating mixture that could easily be applied to a cordierite honeycomb 10.5 inches diameter 6 inches high having 400 square channels per square inch with wall thickness of 6/1000 inch. Excess washcoat was removed by a high pressure air gun, and after drying in a flow of air at 90° C. for 1 hour the resulting coated monolith had 1030 g of washcoat.
Preparation of Catalyst F Ag 2 O/MnO 2 /TiO 2 /SiO 2 (Comparative)
To deionised water (1.2 litre) was added with stirring in a high shear mixer, silver oxide (441 g), MnO 2 (441 g), TiO 2 (156 g) and SiO 2 (104 g) to give a well mixed uniform slurry. This was then ball milled using ceria/zirconia balls for 3 hours to give a d 50 particle size of less than 5 microns. Deionised water was then added and a xanthan gum, Rhodapol from Rhone-Poulenc SA (20.2 g) was added to give a coating mixture with properties enabling easy application to a cordierite honeycomb 10.5 inches diameter 6 inches high having 400 square channels per square inch with wall thickness of 6/1000 inch. Excess washcoat was removed by a high pressure air gun, and after drying in a flow of air at 90° C. for 1 hour the resulting coated monolith had 1017 g of washcoat.
Preparation of Catalyst G MnO 2 /Ag 2 O/TiO 2 /SiO 2 (Comparative)
To deionised water (1.2 litre) was added with stirring with a high shear mixer, silver oxide (707 g), MnO 2 (177 g), TiO 2 (156 g) and SiO 2 (104 g) to give a well mixed uniform slurry. This was then ball milled using ceria/zirconia balls for 3 hours to give a d 50 particle size of less than 5 microns. Deionised water was then added and a xanthan gum, Rhodapol from Rhone-Poulenc SA (20.2 g) was added to give a coating mixture with properties enabling easy application to a cordierite honeycomb 10.5 inches diameter 6 inches high having 400 square channels per square inch with wall thickness of 6/1000 inch. Excess washcoat was removed by a high pressure air gun, and after drying in a flow of air at 90° C. for 1 hour the resulting coated monolith had 1109 g of washcoat.
Preparation of Catalyst H. MnO 2 /Ag 2 O/TiO 2 /SiO 2
To deionised water (1.2 litre) was added with stirring with a high shear mixer, silver oxide (960 g), MnO 2 (25 g), TiO 2 (156 g) and SiO 2 (104 g) to give a well mixed uniform slurry. This was then ball milled using ceria/zirconia balls for 3 hours to give a d 50 particle size of less than 5 microns. Deionised water was then added and a xanthan gum, Rhodapol from Rhone-Poulenc SA (20.2 g), to give a coating mixture with properties enabling easy application to a cordierite honeycomb 10.5 inches diameter 6 inches high having 400 square channels per square inch with wall thickness of 6/1000 inch. Excess washcoat was removed by a high pressure air gun, and after drying in a flow of air at 90° C. for 1 hour the resulting coated monolith had 1208 g of washcoat.
Preparation of Catalyst I Ag 2 O/TiO 2 /SiO 2
To deionised water (1.2 litre) was added with stirring with a high shear mixer, silver oxide (986 g), TiO 2 (156 g) and SiO 2 (104 g) to give a well mixed uniform slurry. This was then ball milled using ceria/zirconia balls for 3 hours to give a d 50 particle size of less than 5 microns. Deionised water was then added and a xanthan gum, Rhodapol from Rhone-Poulenc SA (20.2 g) was added to give a coating mixture with properties enabling easy application to a cordierite honeycomb 10.5 inches diameter 6 inches high having 400 square channels per square inch with wall thickness of 6/1000 inch. Excess washcoat was removed by a high pressure air gun, and after drying in a flow of air at 90° C. for 1 hour the resulting coated monolith had 1147 g of washcoat.
Preparation of Catalyst J Ag 2 O/SiO 2 (Comparative)
To deionised water (1.2 litre) was added with stirring in a high shear mixer, silver oxide (986 g) and SiO 2 (260 g) to give a well mixed uniform slurry. This was then ball milled using ceria/zirconia balls for 3 hours to give a d 50 particle size of less than 5 microns. Deionised water was then added and a xanthan gum, Rhodapol from Rhone-Poulenc SA (20.2 g), to give a coating mixture with properties enabling easy application to a cordierite honeycomb 10.5 inches diameter 6 inches high having 400 square channels per square inch with wall thickness of 6/1000 inch. Excess washcoat was removed by a high pressure air gun, and after drying in a flow of air at 90° C. for 1 hour the resulting coated monolith had 1205 g of washcoat.
Preparation of Catalyst K Ag 2 O/Al 2 O 3 (Comparative)
To deionised water (1.2 litre) was added with stirring in a high shear mixer commercial silver oxide (Johnson Matthey) (986 g) and dispersible Al 2 O 3 (260 g) to give a well mixed uniform slurry. This was then ball milled using ceria/zirconia balls for 3 hours to give a d 50 particle size of less than 5 microns. Deionised water was then added and a xanthan gum, Rhodapol from Rhone-Poulenc SA (26.9 g), to give a coating mixture with rheological properties enabling easy application to a cordierite honeycomb 10.5 inches diameter 6 inches high having 400 square channels per square inch with wall thickness of 6/1000 inch. Excess washcoat was removed by a high pressure air gun, and after drying in a flow of air at 90° C. for 1 hour the resulting coated monolith had 1185 g of washcoat.
Preparation of Catalyst L Ag 2 O/TiO 2
To deionised water (1.2 litre) was added with stirring with a high shear mixer, silver oxide (986 g) and TiO 2 (Millennium Inorganic Chemicals) (260 g) to give a well mixed uniform slurry. This was then ball milled using ceria/zirconia balls for 3 hours to give a d 50 particle size of less than 5 microns. Deionised water was then added and a xanthan gum, Rhodapol from Rhone-Poulenc SA (20.2 g), was added with stirring to give a coating mixture with properties enabling easy application to a cordierite honeycomb 10.5 inches diameter 6 inches high having 400 square channels per square inch with wall thickness of 6/1000 inch. Excess washcoat was removed by a high pressure air gun, and after drying in a flow of air at 90° C. for 1 hour the resulting coated monolith had 1143 g of washcoat.
Test Procedure
A room, typical of a patient isolation room in a hospital, having a volume of 72 cubic metres was humidified to a predetermined relative humidity level by atomising deionised water through three nozzles arranged 120° with respect to each other in a unit about 1 metre high in the centre of the room. Ozone derived from a cylinder of pure oxygen using a plasma ozone generator manufactured by Pacific Ozone Technology was released into the room at a rate that maintained a predetermined level in the room. A computer system taking measurements from ozone and relative humidity sensors placed in the room maintained both humidity and ozone level at the desired levels in the room for at least 30 minutes. The ozone generator was then switched off and the humidification ceased via the computer control system.
The control system then circulated the air in the room through an ozone decomposition catalyst to remove the excess ozone present in the room, by use of a suitable fan. The air flow through the catalyst and the concentration of ozone was measured by sensors and data logged by computer.
Results
The decay curve of ozone concentration in the room as a function of time obeyed an exponential decay. It was a well behaved first order process. For a catalyst that suffers insignificant or predicable deactivation this relationship enables precise calculation of the time required to achieve a particular level of residual ozone in the environment given the first order decomposition rate constant under specific conditions such air flow rate through the catalyst, temperature etc. Deactivation coefficients can be applied to these calculations for field use in computer controlled systems in hospitals etc.
A synopsis of data obtained for different catalyst types in the 72 cubic metre room is given in Table 1.
TABLE 1
Summary of Test Results
Catalyst
Run
Temp
RH
Air Flow Rate constant
Half life
PLC
A
01
17.5° C.
89%
671 m 3 /h 1.14 × 10−3 s −1
10.1 min
03
18.1° C.
89%
826 m 3 /h 0.59 × 10−3 s −1
19.5 min
3.13
D
01
19.0° C.
70%
677 m 3 /h 3.60 × 10−3 s −1
3.21 min
07
18.4° C.
63%
714 m 3 /h 0.78 × 10−3 s −1
14.9 min
1.67
E
01
19.8° C.
47%
705 m 3 /h 3.81 × 10−3 s −1
3.04 min
06
21.0° C.
43%
705 m 3 /h 1.24 × 10−3 s −1
9.32 min
1.05
F
01
24.0° C.
42%
671 m 3 /h 3.41 × 10−3 s −1
3.41 min
09
23.1° C.
89%
671 m 3 /h 1.58 × 10−3 s −1
7.31 min
0.43
G
01
22.0° C.
75%
683 m 3 /h 3.59 × 10−3 s −1
3.22 min
12
17.0° C.
89%
677 m 3 /h 2.28 × 10−3 s −1
5.07 min
0.15
H
01
18.3° C.
89%
661 m 3 /h 3.18 × 10−3 s −1
3.63 min
18{grave over ( )}
19.9° C.
84%
707 m 3 /h 3.10 × 10−3 s −1
3.73 min
0.006
I
01
21.0° C.
85%
657 m 3 /h 2.91 × 10−3 s −1
3.96 min
32
20.0° C.
88%
685 m 3 /h 3.14 × 10−3 s −1
3.68 min
0.007
J
01
17.0° C.
82%
691 m 3 /h 1.31 × 10−3 s −1
8.80 min
02
17.2° C.
83%
691 m 3 /h 1.35 × 10−3 s −1
8.51 min
−0.15
K
01
15.0° C.
84%
683 m 3 /h 2.75 × 10−3 s −1
4.20 min
02
16.0° C.
85%
683 m 3 /h 2.73 × 10−3 s −1
4.23 min
0.015
L
01
17.5° C.
83%
685 m 3 /h 3.69 × 10−3 s −1
3.13 min
04
18.0° C.
80%
685 m 3 /h 3.47 × 10−3 s −1
3.33 min
07
17.6° C.
86%
685 m 3 /h 3.85 × 10−3 s −1
3.00 min
−0.019
We defined a Performance and Longevity Coefficient (PLC) to give an approximate rank to catalysts in this application, PLC=(half-life after N duty cycles−initial half-life)/N. In general the lower the value of the PLC the better is the catalyst, though if the initial performance is inadequate its PLC is irrelevant.
Surprisingly a variety of established ozone decomposition catalysts lost activity very quickly, and this was thought to be due to the very unusually demanding conditions of very high ozone and humidity levels at room temperature which is a relatively low temperature in terms of a catalysed process.
The catalysts of the invention achieved greater than the very high 99.4% conversion of ozone necessary to reduce the level of ozone to levels that are accepted as safe for human exposure surprisingly quickly without any noticeable loss of performance over many use/regeneration cycles.
Comments on the Results
1. Catalyst A
Initial work with a platinum catalyst (6 inch long, 40 g/ft 3 ) showed it had an initial half life of a little more than 10 minutes, but after three experiments this increased to 19.5 minutes even with a significantly higher air flow rate over the catalyst. This was not very much better than the half-life for the natural decay of the ozone in the room that was typically 20.7 minutes. It was therefore concluded the performance of platinum catalyst was inadequate for the application because platinum catalysts did not perform well initially and they rapidly lost activity.
2. Catalysts D and E
Preliminary work on manganese oxide/alumina catalysts showed they performed very much better than Catalyst A, having initial half-lives of about 3 minutes. However durability was not acceptable, the half-life for Catalyst D was about 15 minutes after 7 experiments. The high humidity was shown to be an important factor here—compare half-lives for Catalysts D and E run at different humidities. The lower the humidity the longer the catalyst life, and dehydrating a used catalyst improved its performance.
3. Catalysts F, G, and H
Addition of silver oxide to a manganese oxide catalyst containing titania and silica improved performance in proportion to the amount of silver oxide present and in inverse proportion to the amount of manganese dioxide present. In particular Catalyst H with the highest silver oxide content and lowest manganese dioxide content of these three catalysts had by far the best half-life obtained at the time of testing—3.7 minutes after 18 runs.
4. Catalyst I
This catalyst contained a large proportion of silver oxide with silica and titania and no manganese oxide. Performance was very good indeed, maintaining good activity up to 32 runs when the half life was 3.7 minutes.
5. Catalysts J, K and L
These catalysts were prepared to probe the effect of having just single additions of alumina, silica and titania in silver oxide containing catalysts. Catalyst J had a poor performance (initial half-life 8.8 minutes) showing alumina had a poor influence on the performance of silver oxide in ozone decomposition. Catalyst K had fairly good, though not outstanding performance with an initial half-life of 4.2 minutes. However, Catalyst L containing silver oxide with titania had a very good half-life of 3.1 minutes with good durability.
Example of Catalyst Regeneration
At present, it appears that the two best catalysts investigated are Catalyst I (silver oxide/titania/silica) and Catalyst L (silver oxide/titania); both are being investigated further.
The X-ray diffraction pattern of used, poorly performing catalyst I contained only low intensity reflections characteristic of Ag I 2 O with the dominant silver phase being the mixed oxidation state species A I Ag III O 2 . It was found heating this catalyst in air for 3.5 hours at 150° C. led to the quantitative conversion of the mixed oxide species to Ag 2 O, and recovery of catalytic activity. In the test procedure described previously the half-life for ozone decomposition at 16° C. was 3.8 minutes and 3.5 minutes in a second experiment run at 17° C., similar to the original performance of this catalyst.
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A sterilant such as ozone used for large scale decontamination of, for example, a hospital room, may be destroyed and the room made safe, by passing the atmosphere in the room over a catalyst which is silver oxide in combination with titania. The catalyst may be readily regenerated and used again.
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BACKGROUND OF THE INVENTION
The invention relates to a process for removing dust from a moving paper web, particularly a tissue web, where the air moving along with the web which has a high dust content is removed from the boundary layer. In addition, the invention relates to a device for implementing the process with a first separating box mounted across the sheet running direction.
In tissue-making, 1 to 2% of production, depending on the raw material, product, final dry content and chemical input, collects as dust in the creping sector. On the one hand, this dust has a negative effect on production and on the other, it creates a health and safety risk for the operating staff. Due to the trend towards softer tissue grades and the use of more mechanical pulp, the dust problem is increasing further. The dust comprises fine particles and fibre fragments which are removed from the paper web, primarily at the creping doctor. Some of the dust drops onto the floor of the machine room and the remainder is carried along with the air boundary layer on both sides of the paper web while it is transported from the creping doctor to the reel spool. Part of the dust remains on the surface of the paper web, which can cause difficulties further on in the finishing process.
SUMMARY OF THE INVENTION
The invention is aimed at creating a process and a device where the dust generated on a high-speed paper web, particularly a tissue web, is removed in such a way that the permissible limiting values for dust are not exceeded and, at the same time, the availability of the paper machine, particularly tissue machine, is increased.
The invention is thus characterized by the paper web running at a tangent onto and off the curved guide surface of a separating box, designed as a stabilizer, and by the air being deflected out of the boundary layer and removed by the separating box. Since the separating box is designed as a stabilizer, the web is guided over it exactly and the susceptibility to sheet breaks is substantially reduced because the web runs onto and off the curved guide surface at a tangent. This effect is further enhanced by the air being deflected out of the boundary layer, directed into the separating box and carried away from there. Thus, the vortices and overpressure otherwise common, and which also lead to sheet breaks, are avoided.
A favorable further development of the invention is characterized by the air being extracted from the boundary layer. This further reduces the risk of a sheet break due to overpressure.
A favorable configuration of the invention is characterized by the air being removed evenly over the sheet width. This measure also prevents overpressure occurring locally, which could also lead to sheet breaks, at any event with very thin paper grades.
An advantageous further development of the invention is characterized by the air being removed from the underside of the paper web in addition and then carried off, while the air removed from the underside of the paper web can be extracted by suction. By removing and then extracting the air from the underside, the dust adhering to the paper here is also removed and carried off. As a result it is possible to adhere to the required dust limiting values more easily.
An advantageous configuration of the invention is characterized by adding ambient air when the dust-filled air has been removed in order to avoid vortices from forming. In order to prevent any vortices forming while extracting sufficient air to remove the dust, and thus avoid any risk of a sheet break, dust-free ambient air is fed in at these points and the appropriate pressure thus re-established.
A favorable further development of the invention is characterized by the paper web being stabilized before the air is removed, where air carried along can be carried off by the stabilizer. This additional stabilizing of the paper web before the air is removed facilitates sheet guiding and also diminishes the risk of sheet breaks as a result. If air carried along is deflected by the stabilizer, some of the dust can be removed right away before the air separation process itself.
The invention also refers to a device for removing dust from a moving paper web, particularly a tissue web, with a first separating box mounted across the sheet running direction. It is characterized by the first separating box being designed as a stabilizer with a curved guide surface for the paper web and has a device for deflecting the air boundary layer into a collecting duct in the separating box. Since the separating box is shaped as a stabilizer with a curved guide surface, good sheet guiding is achieved and as a result, the risk of a sheet break is reduced. By carrying the air boundary layer into a collecting duct at the same time, the dust can be removed effectively from the high-speed paper web.
A further development of the invention is characterized by the cross-section of the collecting duct widening towards the drive side of the machine. This has the effect of carrying the air off evenly over the sheet width, thus preventing any vacuum or overpressure locally, which could lead to sheet breaks.
An advantageous configuration of the invention is characterized by a suction slot, which should preferably be adjustable, being provided on the side of the separating box on which the paper web runs onto its surface. The dust-filled air can be removed from this area through the suction slot, with the adjusting facility being used to either remove or extract whatever amount of dust is generated.
A favorable further development of the invention is characterized by the separating box being able to be opened along its entire width. This design provides an easy means of cleaning the box, which is particularly important with dust-filled air in a humid environment.
An advantageous configuration of the invention is characterized by a further separating box being provided on the underside of the paper web and onto which the paper web runs at a very narrow angle, preferably between 1 and 5 degrees, for example from 1 to 2 degrees. By placing a further separating box on the underside of the web it is possible to remove additional dust. Running the web onto the box at a very narrow angle is an easy method of achieving better sheet guiding, thus reducing sheet breaks on sharp edges.
An advantageous further development of the invention is characterized by the additional separating box having a deflection plate, preferably of swivelling design. This deflection plate can be used to guide the air directly into the separating box, while the swivelling design makes it possible to set the amount of air to be removed.
A favorable configuration of the invention is characterized by the bottom separating box being divided into at least two chambers. With this design the air upstream and downstream of the separating box can be carried off separately and the amount to be removed can also be set separately in order to guarantee stable sheet guiding without breaks.
A favorable further development of the invention is characterized by a stabilizer being provided upstream of the first separating box, which has the effect of spreading the paper web. The stabilizer can be of swivelling design. This additional stabilizer provides even more stable sheet guiding, while also generating additional air deflection and thus, reducing dust levels. With a swivelling design the ideal web tension is always guaranteed and if there is a sheet break, this stabilizer can be swung out of the way before the web is fed in again.
An advantageous further development of the invention is characterized by a funnel-shaped suction hood being provided at the doctor area on the drive side of the paper machine. With an extraction facility of this type it is also possible to remove the dust occurring during a sheet break and new web feed, thus reducing the dust loading.
An advantageous configuration of the invention is characterized by a further separating box being provided on the top side of the paper web. By including this box it is also possible to remove any residual dust adhering to the top side of the paper web before it is wound onto the reel spool.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of a tissue machine having a dust removal system in accordance with the invention;
FIG. 2 is an enlarged schematic view of the dust removal system of FIG. 1;
FIG. 3 is an enlarged front view, partly in phantom, of the top separating box of FIG. 2;
FIGS. 4 a and 4 b are cross-section views taken along lines A—A and B—B of FIG. 3, respectively;
FIG. 5 is an enlarged front view, partly in phantom, of the bottom separating box of FIG. 2; and
FIGS. 6 a and 6 b are cross-section views taken along lines C—C and D—D of FIG. 5, respectively.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 contains a diagrammatic view of a dust removal system for a paper web. At the end of the paper production process there is a dryer 1 with a drying cylinder 2 and dryer hood 3 , out of is which hot air is blown onto the paper web 4 running round the drying cylinder 2 . At the inlet the paper web still runs round press rolls 5 , 5 ′. When the paper web 4 has been dried, it is scraped off the drying cylinder 2 by a doctor 6 . A large quantity of dust is produced here and fibers are easily lifted off the surface of the paper. In order to collect and re-use the paper in the event of a sheet break there is a so-called broke chest 7 located beneath the doctor 6 . To improve sheet guiding a stabilizer 8 is provided downstream of the doctor 6 . Part of the dust-filled air carried along with the web rebounds off the stabilizer and is fed into the broke chest 7 , from where this air is extracted. In the event of a sheet break, this stabilizer 8 can be swung downwards so that the paper web can then be fed in again without any difficulty. Adjacent to this stabilizer 8 there is an air separating box 9 on the top side of the paper web which stabilizes the web further and removes the air from the top side of the paper. This is followed by a further separating box 10 on the underside of the paper web, into which the dust-filled air carried along on the underside of the web is deflected. The dynamic impact pressure alone of the air carried along with the web is sufficient to carry this air off and hardly any extraction effect is required. Following the bottom separating box 10 there is usually a traversing measuring device 11 to record the properties of the paper web. A further separation box 12 is provided on the upper side of the web to remove more dust before the web is fed over a work roll 13 and wound onto the reel spool 14 . All dust-filled air currents are removed via a dust collector 15 , where the dust is removed by injecting water into the collector. The air is extracted by a fan 16 , and the dust-filled water drains into a tank 17 and is then discharged as waste water.
FIG. 2 shows the dust extraction part in detail. The illustration shows the drying cylinder 2 from which the paper web 4 is scraped off by the doctor 6 . Part of the dust-filled air is deflected downwards here by the swivelling stabilizer 8 into the broke chest 7 . The paper is fed subsequently to the separating box 9 , which has a curved guide surface 18 to ensure stable sheet guiding. Here at the inlet 18 ′ the paper web runs at a tangent onto this separating box 9 and leaves the surface of the box again at the outlet 18 ″, also at a tangent. Due to this curved guide surface 18 the required web tension is generated to always guarantee stable sheet guiding. At the inlet 18 ′ the air carried along by the paper web is deflected and directed into a suction slot 19 . The wall 20 of the suction slot 19 has a pivoting mounting 29 , which allows the suction slot 19 to be adjusted. In order to clean the separating box this wall 20 can be swung straight upwards, thus making the suction duct 21 accessible for cleaning purposes. The inner surfaces of the suction box are smooth and have no sharp edges, corners or other points at which dust can collect. This also facilitates cleaning of the separating box. When the paper web leaves the separating box 19 at the outlet 18 ″, the paper web 4 is fed to a bottom separating box 10 . Here the web runs onto the box at a narrow angle, preferably between 1 and 5 degrees, here for example from 1 to 2 degrees, which in turn provides good sheet guiding. The air carried along is directed through a suction slot 22 into the box 10 . This suction slot 22 has a deflector plate 23 which can be set to ensure optimum air separation. At the outlet where the paper web leaves the separating box 10 air can be added to prevent vortices forming and avoid any more dust being generated due to underpressure. When the paper web has passed through a traversing measuring device 11 , it runs over a further separating box 12 designed in the same way as the bottom separating box 10 . After this the web 4 runs over roll 13 and is wound onto the reel spool 14 .
FIG. 3 contains a view of the top separating box 9 , with the drive side (marked TS) on the left and the so-called tender side (marked FS) on the right of the paper machine. The air is removed from the separation box 9 through a suction pipe 25 on the drive side.
FIGS. 4 a and 4 b, respectively, show a cross-section of the separating box 9 near the tender side along the line marked A—A and near the drive side along the line marked B—B. This illustration shows how the cross-section of the suction duct 21 increases from the tender side to the drive side. This has the effect of ensuring that the speeds are more or less constant at all points over the sheet width. As a result there are no local differences in air extraction and the risk of sheet breaks is reduced. FIGS. 4 a and 4 b clearly show the route taken by the paper web 4 , leading over the guide surface 18 of the separating box 9 . At the inlet 18 ′ and outlet 18 ″ the web 4 enters and leaves at a tangent and the configuration of the inlet 18 ′ and outlet 18 ″ ensures that no more dust is generated by deflection of the web. The air from the boundary layer is directed through the suction slot 19 into the collecting duct 21 . The wall 20 of the chamber swivels about mounting 29 so that the suction slot 19 can be set and to allow the separating box 9 to be opened for cleaning purposes.
FIG. 5 contains a view of the bottom separating box 10 , again with the drive side of the paper machine on the left and the tender side on the right. Extraction takes place through a duct 26 , 27 on the drive side.
FIG. 6 a shows a cross-section of the separating box 10 on the tender side along the line marked C—C. This illustration clearly shows how the paper web 4 runs onto the separating box 10 more or less on a level. The air is directed into the separating box 10 by the deflector plate 23 . More air can be extracted through an opening 28 when the paper web 4 runs off the separating box 10 . FIG. 6 b contains a cross-sectional view of the separating box 10 on the drive side along the line marked D—D. This figure also shows the ducts 26 and 27 .
The invention is not limited to the designs illustrated.
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A device for removing dust from a moving paper web, where the dust is carried in a boundary layer of air that runs with the web, includes a first separating box mounted across the web running direction. The first separating box has a collecting duct extending across the web running direction, a curved guide surface which guides the paper web, and apparatus for deflecting the dust-laden air boundary layer into the collecting duct.
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FIELD OF THE INVENTION
[0001] This invention relates to a process for decoration of the surface of a substrate.
BACKGROUND OF THE INVENTION
[0002] In this respect the use of paper and polymer films printed with pigments of the dispersed class (Transfer Printing) using machines of the rotogravure type to place an image having a material aspect (wood, marble, stone) or abstract aspect (geometrical patterns) on manufactured articles of various kinds covered with a continuous layer of a paint product derived from a liquid or powder chemical formulation is known.
[0003] Rotogravure printing makes it possible to obtain visual results of a high level of quality, with high image definition, including through four-colour printing, without however generating any effect of a tactile or three-dimensional type, which is a limitation.
SUMMARY OF THE INVENTION
[0004] The object of this invention is to overcome the abovementioned disadvantage of the prior art.
[0005] This object is accomplished through a process for decorating the surface of a substrate comprising the stages of:
printing a three-dimensional decorative pattern on one surface of a polymer film using resin, placing the decorated surface of this film and at least one surface of the substrate in contact and providing thermal energy thereto, and detaching the film from the substrate, onto the surface of which the three-dimensional decorative pattern has been transferred.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is an image of a three-dimensional decorative pattern provided on a surface of a polymer film according to a first example;
[0010] FIG. 2 is an image of a surface of a substrate having the decorative pattern transferred thereto in the first example;
[0011] FIG. 3 is an image of a three-dimensional decorative pattern provided on a surface of a polymer film according to a second example; and
[0012] FIG. 4 is an image of a surface of a substrate having the decorative pattern transferred thereto in the second example.
DETAILED DESCRIPTION OF THE INVENTION
[0013] The aesthetic effect produced by the presence of the three-dimensional decorative pattern is accentuated by exposure of the decorated substrate to obliquely incident light.
[0014] The substrate is for example of metal, in particular aluminium, ceramic or glass. Advantageously, before the film and the substrate are placed in contact the surface of the latter is coated with an optional layer of chromium oxide and then a further layer of a paint product preferably having a thickness of between 1 and 300 μm.
[0015] In principle, the thermal resistance properties of the film used in the process according to the invention should be such as to permit thermal transfer of the decorative pattern to the substrate without compromising its definition.
[0016] This film may have a clear or opaque appearance and be formed of a layer of extruded material belonging to one of the following classes: polyesters, in particular PET, PBT, PTT, polypropylenes, polyamides, polyurethanes, polyvinyls, cellulose, lignin, or several identical or different co-extruded layers.
[0017] The resins for the three-dimensional decorative pattern may for example comprise at least one component selected from: Cellulose acetate, Cellulose acetobutyrate, Cellulose nitrate, Cellulose propionate, Epoxides, Melamine-formaldehyde, Polyamides, Polyamide imide, Polyacrylonitrile, Polybutene-1, Polybutylene terephthalate, Polycarbonate, Polychlorotrifluoroethylene, Polydiallyl phthalate, Polyethylene, Chlorinated polyethylene, Polyether imide, Polyether ketone, Polyether terketone, Polyether sulphones, Polyethylene terephthalate, Phenol formaldehyde, Polyimide, Polyisobutylene, Polymethacrylimide, Polymethyl methacrylate, Poly-4-methylpentene-1, Polyoxymethylene, Polyformaldehyde, Polyacetal, Polypropylene, Polyphenyl ether, Polyphenylene oxide, Polyphenylene sulphide, Polystyrene, Polysulphone, Polythiophen, Polytetrafluoroethylene, Polyurethane, Polyvinyl butyral, Polyvinyl chloride, Chlorinated polyvinyl chloride, Polyvinylidene chloride, Polyvinylidene fluoride, Polyvinyl fluoride, Regenerated cellulose, Silicones, Urea-formaldehyde, Unsaturated polyester, Polydimethylsiloxane.
[0018] In addition to this, these resins may also comprise an expanding additive capable of causing an increase in volume of the three-dimensional decorative pattern on the substrate. This increase in volume is brought about—as will be explained in detail below—by exposure to temperatures within the range from 40 to 300° C. which give rise to the formation of gases, vapours, foam and/or gel or chemical reactions capable of generating macromolecules of larger volume than that of the starting reagents.
[0019] The resins may also comprise any combination of known additives, in particular stabilising additives against the action of solar radiation and atmospheric agents in general.
[0020] These resins may also comprise an organic pigment belonging to at least one of the Nitroso, Nitro, Monoazo, Diazo, Stilbene, Diphenylmethane, Triphenylmethane, Xanthene, Acridine, Quinoline, Methine, Thiazole, Indamine, Indophenol, Azine, Oxazine, Thiazine, Aminoketone, Anthraquinone, Indigoid or Phthalocyanine classes and their derivatives, and/or an inorganic pigment belonging to at least one of the classes:
White pigments: white lead, basic lead sulphate, zinc white, zinc sulphide, lithopone, antimony oxide, titanium dioxide, calcium plumbate; Inert pigments or fillers: barium sulphate (barytes or fixed white), calcium carbonate, dolomite, gypsum, silica, silicates (asbestos, bentonite, kaolin, mica, talc); Black pigments: black iron oxide, carbon blacks (lamp black, charcoal black, ivory black or bone black, graphite); Blue pigments: cobalt blue, ultramarine blue, Prussian blue; Green pigments: chromium phosphate, chromium oxide, hydrated chromium oxide, chromium green, Schweinfurt green, zinc green; Brown pigments: brown iron oxide, ochre, umber, burnt Sienna; Yellow pigments: yellow iron oxide, cadmium yellow, chromium yellow, zinc yellow, nickel titanate, lead cyanamide, strontium chromate; Orange pigments: cadmium orange, chromium orange, molybdate orange, lead silico-chromate; Red pigments: red iron oxide, aluminium minium, lead minium, cadmium red, chromium red; Metal pigments: aluminium, bronze, lead, copper, zinc.
[0031] All in all, the combination of several resins of organic and inorganic nature and possible additives makes it possible to generate a variety of decorative patterns depending upon the type of incision used to create the printing rollers or cylinders through which the resin mixture is printed onto one surface of the polymer film.
[0032] Advantageously, the three-dimensional decorative pattern is printed on one surface of the polymer film through a rotogravure technique, flexographic printing, screen printing, offset printing or a combination thereof which provides for the use of one or more incised rollers. In addition to this it is also possible to print a two-dimensional decorative pattern, in particular using a sublimable ink—together with the three-dimensional decorative pattern—on that surface of the film.
[0033] The provision of heat energy—which causes transfer of the three-dimensional decorative pattern from the film to the substrate—takes place through conduction, for example following contact with a heated surface such as the plate of a press or the cylinder of a rotary press, convection and/or irradiation, in such a way that the temperature lies between 40 and 300° C. This input of thermal energy may for example take place in a continuous or batch stove.
[0034] In an embodiment of the process according to the invention contact between the film and substrate takes place by folding the film in the form of a bag which completely wraps the substrate, joining together the edges of the film and drawing out the air present in the space between the film and substrate in such a way that the decorated surface of the film is substantially in contact with the entire surface of the substrate. As an alternative to drawing out the air, contact may be achieved through mechanical means, such as presses or calenders. For their part the edges of the film may be joined by double-sided adhesive tapes, adhesives, welding or fusion techniques in general.
[0035] Further advantages and characteristics of this invention will be apparent from the following examples of embodiments provided in a non-restrictive way.
EXAMPLE 1
[0036] A bi-orientated polyethylene terephthalate film of nominal thickness 19 μm was printed with a mixture of unpigmented resins which in particular were deposited on one surface through a roller having incisions which recreated a three-dimensional decorative pattern having an oak-grain effect. FIG. 1 is an image of this decorated surface.
[0037] On the other hand, a first layer of chromium metal oxides was formed on the surface of a substrate formed of a sheet of aluminium of nominal thickness 1 mm by using oxidation-reduction processes. The first layer encourages the adhesion of a second layer of paint, obtained following electrostatic deposition of a powder paint product of the polyurethane type (AkzoNobel UZ-884) and its polymerisation through exposure to a temperature of 200° C. for 15 minutes.
[0038] After cooling, the surface of the substrate was placed in intimate contact with the decorated surface of the film and raised to the temperature of 203° C. in about 90 seconds using a hot plate (static press).
[0039] Temperature was monitored through one or more thermocouples in contact with the surface of the substrate.
[0040] Following application of the abovementioned temperature and pressure conditions the three-dimensional decorative pattern was transferred from the film to the substrate as a mirror image.
[0041] The film was finally removed from the decorated substrate, an image of which is shown in FIG. 2 .
EXAMPLE 2
[0042] A bi-orientated polyethylene terephthalate film of nominal thickness 19 μm was printed with a mixture of unpigmented resins which in particular were deposited on one surface through a roller having incisions which recreated a three-dimensional decorative pattern having an oak-grain effect. In the same printing process inks of the dispersed (subliming) class were deposited on the film in order to generate a “covering wood” effect. FIG. 3 is an image of this decorated surface.
[0043] On the other hand, a first layer of chromium metal oxides was formed on the surface of a substrate formed of a sheet of aluminium of nominal thickness 1 mm by using oxidation-reduction processes. The first layer encourages the adhesion of a second layer of paint, obtained following electrostatic deposition of a powder paint product of the polyurethane type (AkzoNobel UZ-881) and its polymerisation through exposure to a temperature of 200° C. for 15 minutes.
[0044] After cooling, the film was wrapped around the substrate in the form of a bag. The bag was sealed by joining the free ends of the film by fusion produced by an ultrasound metal tip. Air present in the space between the film and substrate was then removed using a rotary pump in such a way that the decorated surface of the film was in intimate contact with substantially the entire surface of the substrate.
[0045] The substrate wrapped in the bag was then placed in a stove which was raised to a temperature of 203° C. in approximately 90 seconds through the heat generated by the controlled combustion of a stoichiometric mixture of methane and air.
[0046] Temperature was monitored by one or more thermocouples in contact with the surface of the substrate.
[0047] Following the aforesaid temperature and negative pressure conditions the aforementioned three-dimensional decorative pattern was transferred from the film to the substrate as a mirror image. In addition to the three-dimensional decorative pattern the latter also had the appearance of wood generated by the subliming inks.
[0048] The film was finally detached from the decorated substrate, and an image of this is shown in FIG. 4 .
[0049] Naturally, the principle of the invention remaining the same, the details of construction and embodiments may be varied widely with respect to those described purely by way of example, without thereby departing from the scope of the invention as defined by the appended claims.
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The process for decorating the surface of a substrate comprises the stages of printing a three-dimensional decorative pattern on one surface of a polymer film using resin, placing the decorated surface of the film and at least one surface of the substrate in contact and providing thermal energy thereto, and detaching the film from the substrate onto the surface of which the three-dimensional decorative pattern has been transferred.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention pertains to hand tools, and more particularly to tools for maintaining sports equipment.
2. Description of the Prior Art
The popularity of dart games is increasing rapidly, and the number of both casual players and league players continues to grow. One reason for the widespread participation in dart games is that they can be played almost anywhere a target can be set up, whether indoors or outdoors.
As is known to dart players, a high quality dart is normally composed of four separate components: a brass body, a plastic tip, an aluminum shaft, and a plastic flight. The body typically is a cylinder having a knurled outer diameter and internal threads at both ends. The tip is threaded into one end of the body. The shaft has one end that is threaded into the second end of the body. The second end of the shaft normally has four longitudinally extending slits that frictionally receive corresponding wings of the flight. When properly manufactured and assembled, a dart provides good balance, accuracy, and long service life.
However, with extended use the dart shafts sometimes become bent or otherwise damaged. Using a dart with an imperfect shaft causes wobble and inaccuracy during flight. Consequently, players promptly replace defective shafts with new ones. Shaft replacement is facilitated on many designs by the provision of a small hole drilled through the shaft near its threaded connection with the dart body. A correctly sized pin or the like can be inserted through the shaft hole. Then by firmly holding the body with one hand, the player can apply torque to the pin and thereby unscrew the shaft from the body. Subsequently, a new shaft is screwed into the body.
Unfortunately, a proper pin or the like for inserting into the shaft hole for replacing a faulty shaft is seldom available when needed. Accordingly, a common practice is to use the plastic tip of another dart as the pin. That practice is very risky because of the probability of damage to the tip.
In addition, the threaded joint that renders a dart shaft easily replaceable on a body causes problems in maintaining the shaft tightly in place on the body during normal play. That is because the threaded joint between the body and the shaft has an annoying tendency to loosen during play. As a result, players utilize numerous techniques to keep the shafts tight to their bodies. Some players insert a lock washer between the shaft and the body. Others use tape, caulk, and even potato starch on the threads. Such practices are messy, time consuming, and generally unsatisfactory.
In recognition of the universal problem of maintaining a dart shaft tightly on a body during play while enabling easy removable of the shaft from the body when required, a special tool has been developed and is marketed under the trademark THE DART SHARK. The tool comprises a thin flat plate having a short tip on one end. The tip is designed to enter the holes in dart shafts to aid in removing and replacing the shafts on the dart bodies. The tool has a couple of disadvantages. First, the flat sides and edges of the tip result in sharp corners that tend to deform and upset the soft aluminum material around a shaft hole. In addition, the tip protrudes from the end of the tool so as to create a point like protrusion that tends to quickly wear a hole in a player's pocket or purse.
Thus, a need exists for an improved dart maintenance tool.
SUMMARY OF THE INVENTION
In accordance with the present invention, an inexpensive dart tool is provided that enables a person to easily and quickly remove and replace a dart shaft on a dart body. This is accomplished by apparatus that includes a round pin secured to a handle and extending into a protective recess formed in the handle.
The handle of the dart tool is sized to fit easily into a pocket or purse or on a key ring. For example, the handle may be approximately 3 inches long, 0.38 inches wide, and 0.04 inches thick. The recess is formed near one end of the handle and along one of the handle edges, such that the recess edge intersects the handle edge at two opposed corners. A relatively short land is thus created between the handle end and the adjacent recess corner.
The pin is secured to the handle along the handle land. The pin extends into the recess in a direction parallel to the handle edge. The pin is long enough to pass through the hole of a dart shaft. Further, the recess is large enough to receive the dart shaft between the free end of the pin and the portion of the recess adjacent the second recess corner.
In the preferred embodiment, the handle is made from two identical plates. The pin is placed between the lands of the plates. Then the plates are bent around the pin to bring the two plates into facing contact with each other while wrapping the pin between them. The peripheries of the handle plates are brazed or welded together to form neat and smooth edges that conceal the junction between the two plates.
The dart tool presents a very attractive appearance. Moreover, the location of the pin, which is entirely within the handle recess, minimizes the possibility of the pin free end snagging on or wearing out a pocket or the like in which the tool may be carried.
In a modified embodiment of the present invention, the handle has a recess in the first edge thereof, and the pin is placed perpendicular to the handle edges. The pin is secured to the handle in the area between the second handle edge and the central portion of the recess edge. Preferably, the free end of the pin extends into the recess no farther than the plane of the first handle edge. In another embodiment, the recess is formed in one end of the handle. The pin is parallel to the handle edges, and the pin extends into the recess such that the free end thereof is approximately in line with the handle end. In a further embodiment, the recess is in the form of a slot in the interior of the handle. The pin extends into the slot from one end. The length and width of the slot are sufficient to receive a dart shaft adjacent the pin free end.
The handle and pin of the dart tool of the present invention may be manufactured as a single component, such as by punching them from sheet steel. In that case, the pin is worked as necessary so that it has a round cross section along its length that engages a dart shaft. The pin may also be welded to the handle, if desired, such that the dart tool is made from two components. In that situation, a round pin is used.
Other advantages, benefits, and features of the invention will become apparent to those skilled in the art upon reading the detailed description of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the dart tool of the present invention in use with a dart.
FIG. 2 is a front view of the dart tool of the present invention.
FIG. 3 is a top view of the dart tool.
FIG. 4 is an end view of the dart tool.
FIG. 5 is an exploded perspective view of the construction of one embodiment of the present invention.
FIG. 6 is a front view of a modified embodiment of the present invention.
FIG. 7 is a front view of another embodiment of the present invention.
FIG. 8 is a top view of FIG. 7.
FIG. 9 is a front view of a further modified embodiment of the present invention.
FIG. 10 is a bottom view of FIG. 9.
DETAILED DESCRIPTION OF THE INVENTION
Although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention, which may be embodied in other specific structure. The scope of the invention is defined in the claims appended hereto.
Referring to FIGS. 1-4, a dart tool 1 is illustrated that includes the present invention. The dart tool is particularly useful for maintaining a conventional dart 3, but it will be understood that the invention is not limited to game related applications.
By way of background, the dart 3 normally consists of a cylindrical body 5, to one end of which is secured a tip 7. The body 5 is usually made of brass, and at least a portion of the outer diameter is knurled as at reference numeral 9. The dart tip 7 may be made of a tough plastic material. To the second end of the body is attached a shaft 11. Attachment of the shaft 11 to the body is by a threaded connection 13; the body is normally tapped to receive threads formed on one end of the shaft. Extending through the shaft and perpendicular to the central axis 14 thereof is a small hole 15. A flight 17 is removably pressed into slits fabricated in the free end 18 of the shaft, as is known in the art.
The dart tool 1 of the present invention is employed to facilitate removal of the dart shaft 11 from the body 5 and for tightly reattaching the shaft onto the body. In the construction illustrated in FIGS. 1-4, the dart tool is comprised of a flat handle 19 and a pin 21 secured to the handle. The handle 19 is relatively long, narrow, and thin. I have found that a handle having a length of approximately 3 inches, a width of approximately 0.38 inches, and a thickness of approximately 0.04 inches works very well. That size is small enough to be easily carried in a pocket or purse or on a key chain buL large enough to be easily manipulated for working on the dart 3.
Along a first longitudinal edge 23 of the handle 19 is formed a recess 25. The recess 25 is relatively near one handle end 27 such that a land 29 is created between the handle end 27 and the corner 31 between the handle edge 23 and the adjacent recess edge 33. The preferred length of the land 29 is between approximately 0.45 inches and 0.50 inches.
The pin 21 has a first end 22 that is secured to the handle 19 in the region of the handle land 29. The pin preferably has a diameter of approximately 0.08 inches, and it extends from the handle land into the recess 25 for a distance of approximately 0.25 inches.
The recess 25 has a size and shape that enables it to receive the dart shaft 11 between the free end 35 of the pin 21 and the recess edge 37 distal from the land 29. Accordingly, there is a space of approximately 0.38 inches between the pin free end 35 and the corner 39 between the handle edge 23 and the recess edge 37 remote from the pin 21. Further, a distance of approximately 0.19 inches is maintained between the pin and the central region 41 of the recess edge. With the dimensions as given, the dart tool pin is insertable into the hole 15 of all popular sized dart shafts.
Looking also at FIG. 5, the dart tool 1 may be fabricated from three pieces: two identical handle plates 43 and the pin 21. The two handle plates 43 may be made of stainless steel. The pin is placed between the lands 29 of the two plates. The handle lands are brought into contact with the pin, and the plates are wrapped around the pin so as to enclose it. Simultaneously, the two plates are brought into facing contact with each other along their entire areas except for the portions that are wrapped around the pin 21. Then the entire peripheries of the handle plates, such as the longitudinal edges 23, recess edges 25, and ends 27 are welded or brazed to hide the joint between the two plates and to present the finished appearance of a single piece. If desired, a hole 45 may be punched in the plates for attaching the dart tool 1 to a key ring or the like.
To use the dart tool 1, it is oriented to an attitude such that the plane of the handle 19 is generally perpendicular to the longitudinal axis 14 of the dart 1. The dart is placed within the dart tool recess 25 between the corner 39 and the pin free end 35. The dart is manipulated to bring the hole 15 of the shaft 11 into axial alignment with the dart tool pin 21. Then the pin 21 is inserted into the dart hole 15. The user grips the dart body knurled area 9 with one hand and the tool 1 with the other hand. By applying opposite torques to the dart and tool, the shaft 11 easily unscrews from the body 5. Similarly, a new shaft can be easily screwed back onto the body using the dart tool.
The dart tool 1 enables a player to maintain his darts 3 in a very efficient and inexpensive manner. The tool tightly torques the dart shaft 11 to the dart body 5 such that the shaft remains in place against loosening without the use of adhesives or other undesirable substances. On the other hand, the dart tool enables a player to easily remove even a tightly threaded shaft from the body. Further, the location of the pin 21 within the handle recess 25 protects both the pin against damage and the user's pockets or the like from wearing and snagging when the tool is carried there.
Turning to FIG. 6, a modified dart tool 47 is shown. The dart tool 47 has a handle 49 with first and second longitudinal edges 51 and 53, respectively. Near one end 55 of the handle 49 is a recess 57 in the handle edge 53. The depth of the recess 57 at the central portion 59 thereof and the distance between the corners 61 and 63 at the junctions of the recess with the handle edge 53 are sufficient for the recess to completely receive a dart shaft 11. A round pin 22' is secured to the handle in the land 65 between the recess central portion 59 and the handle first longitudinal edge 51. Preferably, the free end 35' of the pin 22' does not extend out of the recess beyond the plane of the handle second edge 53.
In FIGS. 7 and 8, a dart tool 67 has a handle 69 with a recess 71 formed in one end 73. The recess 71 has the general size and shape of the recess 57 of the dart tool 47 described in conjunction with FIG. 6. That is, the recess 71 has a width and depth at the central portion 72 thereof sized to fully receive a dart shaft 11.
In the dart tool 67, the pin 75 is not a separate component, and the handle 69 is not made of two separate plates. Rather, the pin and handle of the dart tool 67 are fabricated integrally, as by stamping them from a steel sheet approximately 0.08 inches thick. In keeping with an important aspect of the present invention, the pin is processed after stamping so as to have a round cross section. If desired, the tool 67 may include a tip turning accessory in the form of a semi circular cutout 77 in one of the tool side edges 79. Three short but sharp points 81 protrude into the cutout 77.
Next looking at FIGS. 9 and 10, a dart tool 83 has a handle 84 with a recess in the form of an obround slot 85. A round pin 87 protrudes longitudinally into the slot 85. The length and width of the slot are adequate to receive a dart shaft 11 between the slot side edges 89 and between the slot end 91 and the free end 93 of the pin 87.
The dart tool 83 includes a thin ramp 93 on one end of the handle 84. The ramp terminates in a sharp edge 95. The ramp 93 is useful for spreading apart slightly the longitudinal slits in the end 18 of the dart shaft 11 to aid inserting a flight 17 into the slits, as is known in the art.
The dart tool 83 is shown with a tip tightener 97 in the handle 84. The tip tightener 97 is formed as a hole 99 through the handle, with two sharp points 101 protruding into the hole opposite each other. The hole 99 and points 101 are dimensioned to receive and grip the tip 7 of a dart 3 in order to tighten the tip to and untighten it from the dart body 5.
The pin 87 of the dart tool 83 is shown as a separate component welded in the slot 85. It will be appreciated, of course, that the dart tool 83 can be fabricated as a single component, similar to the dart tool 67 of FIGS. 7 and 8, or as three components like the dart tool 1 shown in FIG. 5. Further, the single component dart tool 67 of FIGS. 7 and 8, the two component dart tool 83 of FIGS. 9 and 10, and the three component dart tool 1 of FIG. 5 may be used in any combination with the pin and recess designs of FIGS. 3-5, 6, 7 and 8, and 9 and 10. In each case, the resulting dart tool functions very well for its intended purposes of easily and quickly removing and replacing a dart shaft 11 on a dart body 5, while being convenient to carry for having on hand when needed.
Thus, it is apparent that there has been provided, in accordance with the invention, a dart tool that fully satisfies the aims and advantages set forth above. While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications, and variations as fall within the spirit and broad scope of the appended claims.
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A dart tool simplifies the task of replacing a dart shaft on a dart body. The dart tool is comprised of an elongated handle that defines a recess. A pin secured to the handle extends into the recess. The pin and recess are dimensioned to enable the pin to enter the holes normally present in dart shafts. Applying torque to the dart tool and the dart enables rapid removal and tight replacement of the shaft on the dart body.
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This application claims the benefit of priority based upon U.S. Provisional Application No. 60/038,115, filed on Feb. 20, 1997, the entire disclosure of which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention pertains to a method and system for radiological image guidance in percutaneous surgery. The invention further pertains to a friction transmission mechanism with axial loading.
2. Description of the Related Art
As an alternative to traditional open surgery, percutaneous surgery has been found to significantly reduce morbidity and post-operative recovery time.
However, percutaneous needle access of the surgical target may be difficult, and usually requires an extensive amount of experience and skill on the part of the surgeon. The above problem is exacerbated by the fact that prior art radiological image guidance techniques and associated imaging devices do not provide effective three dimensional information to the surgeon regarding needle insertion.
In order to overcome the above problem, several robotic systems have been proposed to date to assist in needle placement.
According to one solution, a stereopair of two x-ray views registered to a common fiducial system having an instrumented passive linkage with five degrees of freedom (or a “5DOF instrumented passive linkage”) is used. The stereopair of views is used to position a passive needle guide. See Potamianos, P., Davies, B. L. and Hibberd, R. D., “IntraOperative Imaging Guidance for Keyhole Surgery Methodology and Calibration”, Proceedings for the First International Symposium on Medical Robotics and Computer Assisted Surgery, Pittsburgh, Pa., pp. 98-104 (1994); see also Potamianos, P., Davies, B. L. and Hibberd, R. D., “Intra-Operative Imaging Guidance for Keyhole Surgery Methodology and Calibration”, Proceedings for the First International Symposium on Medical Robotics and Computer Assisted Surgery, Baltimore, Md., pp. 156-164 (1995). It has further been proposed to provide an active needle guide in the form of an active robot instead of the passive needle guide mentioned above. See Bzostek, A., Schreiner, S., Barnes, A. C., Cadeddu, J. A., Roberts, W., Anderson, J. H., Taylor, R. H., Kavoussi, L. R., “An Automated system for Precise Percutaneous Access of the Renal Collecting System”, submitted for review to the Proceedings of the First Joint conference of CVRMed and MRCAS, Grenoble, France (1997).
Although the above systems successfully address issues of image-to-robot registration and provide convenient means for defining target anatomy, they can nevertheless be expensive and cumbersome in an operating room environment. Moreover, for the implementation of the active robot mentioned above, the radiological profile of the end-effector, or needle, may interfere with a clear view of the target.
Percutaneous renal access procedures are often performed in radiology suites, where sophisticated imaging devices are available. Performing percutaneous surgery in the operative room has the advantage of significantly reducing cost, improving availability, and allowing the surgeon to have full control over the entire procedure. The imaging commonly available in the operating room involves uni-planar fluoroscopy provided by a “C-arm” imaging device, as described for example in U.S. Pat. No. 5,549,439.
Percutaneous surgery in the form of manual renal access normally proceeds according to a system of superimposed registration, which is described below.
The urologist positions a conventional C-arm imaging device over the renal collecting system, chooses the target calyx of the collecting system and the skin insertion site. The C-arm of the imaging device is then positioned, or “frogged”, to register or align the desired skin insertion site and the target calyx so that they are superimposed in the image generated by the C-arm imaging device. The alignment of the desired skin insertion site and the target calyx defines the trajectory to be followed by the needle during its insertion, or the needle trajectory. Once the needle trajectory has been determined through a positioning of the C-arm, the C-arm is locked against changing its orientation, thereby resulting in an effective memorization of the needle trajectory. Next, the urologist manually holds the needle in position on the desired skin insertion site and in the direction of the needle trajectory memorized by the locked orientation of the C-arm. The needle, the insertion site and the target calyx are, as a result, superimposed as a single point on the image generated by the C-arm imaging device. Thereafter, the urologist manually inserts the needle into the insertion site while viewing the superimposed image to maintain the prescribed alignment along the needle trajectory.
A disadvantage of the above procedure is that it does not provide a simultaneous lateral view of the renal collecting system. The reason for the above is that the C-arm imaging device according to the mentioned procedure is used to maintain axial needle alignment, and can therefore not provide needle depth imagery. Therefore, according to the foregoing procedures, to gain access to the renal collecting system, the depth of insertion must be determined both as a function of the surgeon's experience and on a trial and error basis.
Additionally, the foregoing systems do not provide an effective needle driver which is both simple in its mechanical design and which exhibits a space-saving, miniaturized construction while allowing an efficient force and power transmission to the needle. Conventional needle driving techniques are based on holding the needle head and not the barrel of the needle, the motion of the needle being induced by moving the support of the needle head. The above technique does not allow radiolucent constructions. Moreover, supporting the needle from its head tends to disadvantageously maximize the unsupported length of the needle, thus facilitating needle deflection under the insertion force. Examples of such needle drive systems based on holding the needle head are included in the publication by Bzostek et al.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a simple and effective method and system for radiological image guidance in percutaneous surgery which overcome the disadvantages of the prior art.
The above object, together with others to become apparent as the description progresses, is achieved by the provision of a method for performing radiological-image-guided percutaneous surgery with a system which includes a radiological image generating device for generating an image of a target anatomy of a patient to be operated on, and a needle insertion mechanism disposed adjacent the image generating device and having a needle adapted to be inserted into the patient. The method comprises the steps of: determining a needle trajectory of the needle by positioning the image generating device for aligning, in the image generated by the image generating device, a desired skin insertion site of the patient with a target region of the target anatomy; locking the needle in a direction of the needle trajectory; and repositioning the image generating device to obtain a lateral view of the needle trajectory for viewing an insertion depth and path of the needle during its insertion into the patient.
The invention further pertains to a system for performing the method described above, comprising: a radiological image generating device for generating an image of a target anatomy of a patient to be operated on for determining a needle trajectory to be followed through the patient, the image generating device being positionable to generate an image of the target anatomy from a plurality of directions; and a needle insertion mechanism disposed adjacent the image generating device and having a needle adapted to be inserted into the patient and to be locked in a direction of the needle trajectory.
According to one aspect of the invention, the needle insertion mechanism comprises both a needle and a needle driver, which includes: a first rotational component having a first contact face and being adapted to rotate about a rotational axis; and a second rotational component coaxial with the first rotational component and having a second contact face facing the first contact face and spaced therefrom, the needle being spaced from the rotational axis and further being pressed between the contact faces thereby applying an axial force to each of the contact faces directed parallel to the rotational axis, the axial force effecting a frictional engagement of the needle with the contact faces, the second rotational component further being adapted to rotate about the rotational axis such that, when the rotational components rotate about the rotational axis, the frictional engagement of the needle with the contact faces effects a translational motion of the needle.
The invention further pertains to a motion transmission mechanism comprising both an output shaft and an output shaft driver, which includes: a first rotational component having a first contact face and being adapted to rotate about a rotational axis; and a second rotational component coaxial with the first rotational component and having a second contact face facing the first contact face and spaced therefrom, the output shaft being spaced from the rotational axis and further being pressed between the contact faces thereby applying an axial force to each of the contact faces directed parallel to the rotational axis, the axial force effecting a frictional engagement of the output shaft with the contact faces, the second rotational component further being adapted to rotate about the rotational axis such that, when the rotational components rotate about the rotational axis, the frictional engagement of the output shaft with the contact faces effects a translational motion of the output shaft.
The simplicity of the method and system according to the present invention is achieved by combining the proven radiological image guidance procedures and devices of the prior art with a simple and cost-effective needle injection device which exhibits an extremely low radiological profile. The needle injection device further provides actuated needle motion in conjunction with a mechanical manipulator designed to be used in existing operating rooms without the necessity of additional computers or personnel.
Accordingly, the method and device of the present invention mimic and improve upon the surgeon's standard technique. The key advantages of the present invention are that it involves the use of a proven radiological needle alignment procedure, improves accuracy in comparison with purely manual needle positioning techniques, and enables lateral fluoroscopic monitoring of the needle without necessitating computer-based vision and robotic systems. The present invention results in a shortening of procedure durations, improves upon patient safety, ensures and improves upon equipment sterility, and reduces the radiation exposure of surgeons.
According to the present invention, a method and system are provided which, to an extent, mimic the surgical technique of superimposed registration used in the prior art and described above. Thus, the invention contemplates registering or aligning a C-arm and needle according to the prior art. However, in the accordance with the invention, the needle is mechanically locked so as to lock the needle axis along the desired needle trajectory by any suitable means, and preferably by a robotic manipulator. Thus, the needle trajectory according to the invention is memorized by a locked orientation of the needle proper, and not of the C-arm, thereby allowing the surgeon to position or “frog” the C-arm to obtain a lateral view of the target anatomy and needle. As a result, the insertion depth of the needle and the path of the needle during its insertion may be observed directly by the surgeon on the image provided by the laterally positioned C-arm. Direct observation of insertion depth advantageously allows the surgeon to compensate for soft tissue deflection of the target, such as the kidney, surrounding tissue. Thus, in comparison with prior art techniques, the method according to the present invention results in safer and more accurate percutaneous procedures.
A further advantage of the method according to the invention is that it does not require image correction and calibration. By superimposing the needle, the insertion site and the target, any image distortions are identical, and therefore, cancel each other. Moreover, the method of the present invention requires direct observation by only the surgeon involved, and hence does not necessitate image-processing that is computer based, thereby significantly reducing operative time and expense.
In order to drive the needle according to the present invention, a needle driver is provided which converts rotational to translational motion in a transmission element which is adapted to receive the barrel of the needle therein. Power is transmitted to the needle through friction forces from contact faces between which the needle is pressed. Thus, the novelty of the transmission resides in providing a mechanism in which a force is generated which extends in the direction of the axis of rotation and which is normal to the direction of friction forces thus leading to the conversion of the rotational motion to the translational motion mentioned above. The needle driver constructed according to the invention thus results in axial loading of the contact faces which is significantly larger than similarly sized radial loading systems of the prior art, yielding increased efficiency in the transmission of force and power. While mechanisms involving the conversion of rotational motion to translational motion through friction abound in the prior art, these systems involve the generation of a force which is oriented only radially with respect to the axis of rotation, and not axially with respect to this axis. On the other hand, the invention advantageously involves an axially loaded friction mechanism for converting rotational motion to translational motion.
Additionally, the needle driver according to the invention, by virtue of providing a construction where the needle is held by its barrel and not by its head, allows a radiolucent construction and advantageously decreases the unsupported length of the needle for substantially preventing needle deflection under the insertion force.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing objects of the invention, together with other objects and advantages which may be attained by its use, will become more apparent upon a review of the following detailed description of the invention taken in conjunction with the drawings. In the drawings, where like reference numerals identify corresponding components:
FIG. 1 is a perspective view of a system for radiological image guidance in percutaneous surgery;
FIG. 2 is a perspective view of the manipulator of the system according to FIG. 1 attached to an operating table shown in a partially sectional view;
FIG. 3 is a perspective view of a needle driver of the manipulator of FIG. 2;
FIG. 4 is an exploded view of the transmission element of the needle driver of FIG. 3;
FIG. 5 a is a top plan view of the transmission element of FIG. 4;
FIG. 5 b is a detail of the view shown in FIG. 5 a;
FIG. 6 is a perspective schematic view of an axially loaded friction transmission mechanism which functions according to the same principle as the needle driver of the present invention;
FIG. 7 a is a schematic front view of the mechanism of FIG. 6;
FIG. 7 b is a schematic cross-sectional view taken along line 7 b — 7 b in FIG. 7 a;
FIG. 8 is a graph of the dependence of the transmission efficiency on the position of the output shaft with respect to the input shafts of the mechanism shown in FIGS. 6, 7 a and 7 b ; and
FIG. 9 is a photograph of an exemplary system for radiological image guidance in percutaneous surgery, in accordance with the invention.
DETAILED DESCRIPTION OF THE INVENTION
As seen in FIG. 1, a system 1 for radiological image guidance in percutaneous surgery is shown. The system is disposed in an area suitable for surgery, such as an operating room. A novel needle insertion mechanism 3 comprises a passive needle manipulator 5 which maintains the needle 7 in position above a patient 9 , and is effective in minimizing the surgeon's radiation exposure and disturbances in the needle trajectory during the insertion of the needle through insertion site 11 toward target 13 . System 1 requires neither a fully actuated robot nor position feedback sensors by virtue of using a superimposed registration technique as described previously, thus minimizing costs.
As further shown in FIG. 1, the system further includes an operating room table 16 for the patient, and a conventional C-arm imaging device 17 including a C-arm 19 and an image screen 21 . The C-arm imaging device may, for example, comprise the X-ray system disclosed in U.S. Pat. No. 5,549,439. Thus, by way of example, C-arm 19 comprises a top arm 23 hingedly connected to a bottom arm 25 and pivotable by means of a suitable actuator 34 about a horizontal axis. A C-shaped bracket 27 is fixed to the free end 29 of top arm 23 . The C-arm. imaging device 17 further comprises an X-ray radiation source 31 at a free end thereof. The other free end of bracket 10 bears an X-ray image sensor 33 which lies in the radiation beam of source 31 . As can be seen from FIG. 1, bracket 27 is suspended from free end or wrist 29 so that it can be pivoted about three axes which are at right angles to one another. An X-ray image generated by the C-arm imaging device 17 can be seen on screen 21 coupled to the source 31 and sensor 33 .
Manipulator 5 shown in FIGS. 1 and 2 is preferably an FDA approved manipulator arm sold under the trademark LEONARD and manufactured by Leonard Medical, Inc. Manipulator 5 has six degrees of freedom made possible by the provision of three rotational joints and one spherical joint. The joints may be spring loaded (not shown) to compensate for gravitational loading, and are not equipped with motors or position encoders. These joints may be locked in the desired position, preferably simultaneously, as dictated, for example, by a needle trajectory 35 determined through the superimposed registration technique described above. A locking of the joints may be effected, for example, by vacuum operated brakes (not shown).
The needle insertion mechanism 3 shown in FIGS. 1 and 2 further comprises an active needle driver 37 attached to the distal end of passive arm 39 of the manipulator 5 . Needle driver 37 is shown in FIG. 1 as being disposed between source 31 and sensor 33 such that the axis of the needle can be aligned along the X-ray. Needle driver 37 may be actuated by a variable speed DC motor which the surgeon regulates via a conventional joystick control 41 . As disclosed in U.S. Pat. No. 5,116,180, joystick technology for effecting manipulations in multiple degrees of freedom is well within the skill of the artisan.
As further seen in FIGS. 1 and 2, a custom designed rigid side rail 43 is mounted on table 16 to provide a sturdy base for the manipulator 5 . The provision of a rigid side rail is critical for maintaining the needle trajectory under the insertion force of the needle.
Needle driver 37 is preferably constructed of plastic, such as acrylic, and could be manufactured inexpensively as a disposable unit. Needle driver 37 is easily sterilized and is further made of a material and/or materials which are almost completely radiolucent, thus enabling the surgeon to monitor the surgery with an unimpeded fluoroscopic image.
A novel feature of the insertion device is that it grasps the barrel of the needle and not the head of the needle, as seen in FIGS. 1-3, and as described in further detail below. The above significantly reduces the unsupported length of the needle during insertion, thus advantageously minimizing lateral flexure thereof under insertion loading.
As seen in FIG. 3, needle driver 37 comprises a needle driver housing 44 , and a transmission element 45 mounted on the housing, preferably by means of a ball lock mechanism (not shown). The transmission element comprises a trocar needle 7 used as the output shaft thereof. An input shaft 47 of transmission element 45 is driven by a DC motor (not shown), which is located in part in needle driver housing 44 .
FIG. 4 shown an exploded view of transmission element 45 which comprises a transmission housing 49 preferably constructed of acrylic or other radiolucent material. Transmission housing 49 defines a first rimmed bore 51 extending thereacross and adapted to slidingly receive input shaft 47 and an axial-loading bushing 53 therein. Bushing 53 slides over input shaft 47 , best seen in FIG. 4, and is axially loaded through O-ring 55 with a nut 57 . Transmission housing 49 further defines a second rimmed bore 56 therein transversely tangential to first rimmed bore 51 within transmission housing 49 as shown. Input shaft 47 , bushing 53 and nut 57 are likewise preferably constructed of acrylic or other radiolucent material. Input shaft 47 is further coupled at a driven end 59 thereof to the D.C. motor, and at another end thereof to nut 57 . By coupling input shaft 47 to nut 57 , the D.C. motor drives bushing 53 indirectly through nut 57 at the same rotational speed as input shaft 47 . Bushing 53 is driven by loading O-ring 55 with nut 57 . In the shown construction, the O-ring has a function equivalent to that of a spiral spring, and is used instead of the spring in order to achieve better radiolucency.
The disc-shaped construction of transmission housing 49 advantageously provides a large surface around needle 7 which presents a uniform thickness and density for exhibiting a uniform attenuation of the X-ray image such that views of the target and biological surfaces surrounding the same are not impeded during percutaneous surgery.
FIG. 5 a is a top view of the assembly, while FIG. 5 b shows a detail of FIG. 5 a . As shown in FIGS. 5 a and 5 b , needle 7 slides in the second rimmed bore 56 of transmission housing 49 , and is, as a result, pressed between a contact face 61 of input shaft 47 and contact face 63 of bushing 53 , which contact face 63 corresponds to one of the two ends of the bushing. Contact faces 61 and 63 impart an axial force to needle 7 corresponding to the transmission friction force between the contact faces and needle 7 . A fillet 65 may be placed at the base of contact face 61 of the input shaft 47 to diminish a high concentration of stress at that location, which corresponds to the weak point of the shaft.
The transmission between the contact faces 61 and 63 tends to slip when overloaded. The overload force, however, is adjustable through a manipulation of nut 57 .
The above design of needle driver 37 allowed, during one test, the generation of a drive force of up to 30 Newtons for a maximum pre-load. The needle was placed as close as possible to contact face 61 of input shaft 47 . The above arrangement resulted in an efficiency of approximately 85% of the transmission.
A photograph of an exemplary system for radiological image guidance in percutaneous surgery in accordance with the invention shown in FIG. 9 .
FIGS. 6, 7 a and 7 b provide a more detailed understanding of the principle involved in the operation of the needle drive according to the present invention by providing illustrations of a mechanism which functions similarly to the needle drive. Thus, as shown in FIGS. 6, 7 a and 7 b , the non-backlash transmission mechanism converts the rotational motion indicated by arrow R of disks 67 and 69 into a translational motion indicated by arrow T, and vice versa. Output shaft 71 is squeezed between contact faces 73 and 75 of disks 67 and 69 which generate the transmission friction. As seen in FIG. 6, bushings 77 , 79 , 81 and 83 are fixed against movement for maintaining the relative position of the shafts. The kinematics of the shown mechanism is shown more clearly in FIGS. 7 a and 7 b.
As seen in FIGS. 7 a and 7 b , disks 67 and 69 are axially loaded with the force F f =μF n . Here, μ is the Coulomb coefficient of friction between disks 67 and 69 and the output shaft 17 . The output force of the transmission, that is, F, is bounded by 2F f , which means that F≦2F f . Therefore, the transmission slips when overloaded, as mentioned with respect to the needle driver above. Theoretically, the friction force acts on contact line AB on contact faces 73 and 75 of disks 67 and 69 , respectively. In a planar Newtonian system of coordinates xOy as shown in FIG. 7 b centered on the rotational axis 89 of inputs shafts 85 and 87 , the absolute velocity of a contact point P on either of the disks 67 or 69 with respect to point O is given by the equation:
O V P =ωr (x) (eq. 1)
where ω is the angular velocity of inputs shafts 85 and 87 and r (x) is the position vector of point P. The x and y components of V may be calculated according to the following equations:
O V P x =ωd (eq. 2a)
O V P y =−ωx (eq. 2b)
where d is the distance between the input shaft rotational axis 89 and the output shaft axis 91 , and coordinate x defines the position of point P on line AB. From the equations above, it can be seen that O V P x is constant along line AB and O V P y is linearly dependent on x. The first equation defines the kinematic transfer function of the transmission as:
V=ωd (eq. 2c)
where V is the translational velocity of output shaft 71 and is the angular velocity of inputs shafts 85 and 87 . Similarly, the dynamic transfer function of the transmission may be calculated as:
F=T/d; F≦ 2 μF n (eq. 3)
where T is the input torque.
The transmission of rotational motion to translational motion and vice versa dissipates mechanical power due to the y-directional sliding friction of disks 67 and 69 with respect to output shaft 71 on contact line AB. The velocity of a point P of either one of the disks relative to output shaft 71 (when the transmission is under-loaded, (that is, when F≦2 μF n ) is given by:
71 V P x =0 (eq. 4a)
71 V P x =−ωx (eq. 4b)
The above equations show that there is no energy loss due to the x-directional friction. However, the y-directional friction components exhibit energy dissipation and hence mechanical work. The lost energy W l and transmitted energy W t of the transmission may be calculated using the Coulomb friction model according to the following equations:
W l =(4/21) 0 ∫ l F f 71 V p y dx=−μF n ω 1 (eq. 5a)
W t =2 F f 71 V p y =2μ F n ωd (eq. 5b)
where
l =(| AB|/ 2)={square root over ( R 2 −d 2 +L )}
where R is the radius of disks 67 and 69 . In arriving at equations 5 a and 5 b , maximum loading F=2 μF n of the transmission was considered, and the static and dynamic coefficients of friction p were considered equal (which amounts to the most disadvantageous case). As a result of the above, the power efficiency of the transmission may be calculated as:
ε (d) =W t /( W t −W l )=2 d /(2 d +1) (eq. 6)
noting that the efficiency depends solely on the ratio of d in R. Defining the above ration as f=d/R, the efficiency of the transmission becomes:
ε (d) =2 f /(2 f +{square root over (1− f 2 +L )}) (eq. 7)
The dependence of the efficiency on the position of the output shaft 71 with respect to the input shafts 85 and 87 is graphically represented in FIG. 8 . The extremes of the graph shown in FIG. 8 illustrate the output power is 0 if d=0 and no power is lost if d=R. Thus, the graph suggests that the dimension d should be set as close to R as possible in order the maximize the efficiency of the transmission.
It is noted that in the mechanism shown in FIGS. 6, 7 a and 7 b , a rotational motion may be imposed over the translational motion of output shaft 71 by either using different materials (which lead to different coefficients of friction) for the respective disks 67 and 69 , or by slightly inclining the axis 91 of the output shaft 71 with respect to the rotational axis 89 of the disks 67 and 69 in the y direction.
It can be appreciated from the mechanism depicted in FIGS. 6, 7 a and 7 b that the mechanism functions according to the principle described for the needle driver 37 of the present invention. Thus, input shafts 85 and 87 in FIGS. 6, 7 a and 7 b correspond, respectively, to input shaft 47 and bushing 53 shown in FIGS. 3, 4 , 5 a and 5 b , since input shafts 85 and 87 transmit rotational motion. Moreover, contact faces 73 and 75 of disks 67 and 69 in FIGS. 6, 7 a and 7 b correspond to contact faces 61 and 63 of input shaft 47 and bushing 53 in FIGS. 3, 4 , 5 a and 5 b , while output shaft 71 in FIGS. 6, 7 a and 7 b corresponds to needle 7 shown in FIGS. 1-4, 5 a and 5 b . Moreover, by being fixed against movement for maintaining the relative position of the shafts, bushings 77 and 79 on the one hand, and 81 and 83 on the other hand, as shown in FIG. 6, correspond to ends of second rimmed bore 56 and to ends of first rimmed bore 51 shown in FIGS. 3, 4 , 5 a and 5 b , respectively.
The above description of the principle of operation of the needle driver 37 makes it clear that greater transmission efficiency may be obtained by placing the needle 7 closer to radial edges of contact faces 61 and 63 of input shaft 47 and 5 bushing 53 , as suggested by the graph of FIG. 8 .
As an example of the method according to the present invention, a percutaneous procedure involving renal access is described below.
According to the present invention, the urologist positions C-arm imaging device 17 over the renal collecting system of patient 9 , chooses the target calyx 13 and the skin insertion site 11 . The C-arm is then positioned to align the desired skin insertion site and the target calyx so that they are superimposed in the image generated by the C-arm. The alignment of the desired skin insertion site and the target calyx defines the trajectory to be followed by the needle during its insertion, or the needle trajectory 35 . Once the needle trajectory has been determined through a positioning of the C-arm, the needle 7 is mechanically locked so as to lock the needle axis along the desired needle trajectory 35 by locking manipulator 5 to hold the needle in the desired orientation. Thus, the needle trajectory according to the invention is memorized by a locked orientation of the needle proper, and not of the C-arm, thereby allowing the surgeon to position or “frog” the C-arm to obtain a lateral view of the target anatomy and needle. As a result, the insertion depth of the needle and the path of the needle during its insertion may be observed directly by the surgeon on the image provided by the laterally positioned C-arm, indicated by broken lines 93 in FIG. 1 . Direct observation of insertion depth advantageously allows the surgeon to compensate for soft tissue deflection of the target, such as the kidney, and surrounding tissue.
The invention addresses a particularly difficult surgical task by designing a simple and cost-effective robotic system and method which can be rapidly transferred to the clinical setting. One of the important advantages of the method and system according to the invention is the uncomplicated mimicry they provide of the surgeon's technique while improving both the safety and the accuracy of percutaneous procedures. The invention is fully compatible with, but does not require a computer-based vision system or a fully actuated robot with joint position feedback.
The full content of all of the documents and/or patents mentioned in this specification is incorporated herein by reference.
Although only the preferred embodiments have been described in detail above, those of skill in the art will readily appreciate that many modifications of the exemplary embodiments are possible without departing from the spirit or scope of the invention as set forth in the appended claims.
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A method for performing radiological-image-guided percutaneous surgery with a system which includes a radiological image generating device for generating an image of a target anatomy of a patient, and a needle insertion mechanism disposed adjacent the image generating device and having a needle adapted to be inserted into the patient. The method includes the steps of: determining a needle trajectory of the needle by positioning the image generating device for aligning, in the image generated by the image generating device, a desired skin insertion site of the patient with a target region of the target anatomy; locking the needle in a direction of the needle trajectory; and repositioning the image generating device to obtain a lateral view of the needle trajectory for viewing an insertion depth and path of the needle during its insertion into the patient. Moreover, a motion transmission mechanism includes an output shaft and an output shaft driver which has two rotational components having respective contact faces between which the output shaft is pressed for frictional engagement therewith. The frictional engagement creates a force between the output shaft and the rotational components which is parallel to the rotational axis of the rotational components for allowing the rotational components to impart a translational motion to the output shaft by virtue of their rotational motion.
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FIELD OF THE INVENTION
[0001] The present invention relates to a tag capable of storing data remotely readable by an adapted read terminal. The invention more specifically aims at a technology of remote identification by electromagnetic waves, currently called RFID, for “Radio Frequency Identification”, in the art. Devices operating at frequencies ranging between 10 MHz and 10 THz are more specifically considered herein.
DISCUSSION OF PRIOR ART
[0002] Data exchange systems in RFID technology are currently used to recognize and/or to identify, at small or medium distance, all types of objects bearing an adapted tag.
[0003] FIG. 1 very schematically illustrates a remote identification system in RFID technology, comprising a read terminal 1 and an identification tag (TAG) 3 . Read terminal 1 especially comprises an antenna, coupled to a radio wave transceiver device. Tag 3 contains identification data and is capable, when placed close to the read terminal, of receiving the signal transmitted by the read terminal and of specifically interfering with this signal according to its identification data. This interaction is detected by read terminal 1 , which can deduce the tag identification data therefrom.
[0004] There mainly exist two types of RFID tags, that is, tags comprising an integrated electronic circuit, called chip tags, and tags comprising no integrated electronic circuit, generally called chipless tags in the art.
[0005] RFID chip tags generally comprise an antenna, an electronic circuit, a memory for storing an identification code, and a transponder for receiving the signal transmitted by the read terminal and for transmitting as a response, in a determined frequency band, a modulated signal containing the identification code stored in the memory. Some RFID chip tags, called active tags, comprise a battery for powering the chip. In other RFID tags, called passive tags, part of the power carried by the radio waves transmitted by the read terminal is used to power the chip. Passive tags have the advantage of requiring no internal power supply.
[0006] Due to the presence of electronic circuits in RFID chip tags, such tags have a non-negligible cost. The forming of chipless tags has been provided to decrease this cost. RFID chipless tags are considered herein.
[0007] FIG. 2 is a perspective view schematically showing an example of chipless RFID tag 21 . Tag 21 is formed from a dielectric substrate 23 , for example, having the shape of a rectangular wafer of 18×35 mm, with a thickness of approximately 1 mm. The rear surface of substrate 23 is covered with a metal ground plane 25 . On the upper surface side of substrate 23 are formed separate parallel conductive strips, five strips 27 a to 27 e in the present example. Strips 27 a to 27 e differ from one another by their dimensions (length and/or width) and by their surface areas.
[0008] Tag 21 forms a structure with resonant elements capable of interfering with a radio signal transmitted by an RFID read terminal (not shown). Each conductive strip 27 a to 27 e behaves as a resonant LC-type circuit, capable of retransmitting a specific electromagnetic wave that can then be detected by the read terminal. Inductance L especially depends on the length of the conductive strip. Capacitance C corresponds to the capacitance formed between the conductive strip and ground plane 25 , and especially depends on the conductive strip surface area and on the thickness of the substrate as well as on its dielectric properties. Thus, each conductive strip 27 a to 27 e determines, by its geometry, a resonance frequency of tag 21 . In this example, each strip 27 a to 27 e defines a specific resonance frequency ranging between 5 and 6 GHz.
[0009] In operation, the read terminal transmits a radio signal having a spectrum comprising all the resonance frequencies of the tags that it is likely to read. If tag 21 is close to the read terminal, the read terminal detects a peak (and/or a trough) of the signal at the resonance frequencies determined by strips 27 a to 27 e, which translates as the appearing of five different lines in the power spectrum of the radio signal. The positions of these five strips in the spectrum enable the read terminal to uniquely identify tag 21 .
[0010] Chipless RFID tags are passive by nature since they require no electric power supply.
[0011] Although the tags described in relation with FIG. 2 are less expensive to manufacture than chip tags, their cost however remains non negligible. This is especially due to the fact that the support substrate used to form the tag should comprise a ground plane and have a specific thickness and well-defined dielectric properties.
[0012] It would be desirable to have tags of very low cost, which can especially be used as disposable identification devices, for example, in food packaging.
[0013] Further, the data storage capacity per surface area unit of chipless tags of the type described in relation with FIG. 2 is relatively low. In the example of FIG. 2 , a tag of 18×35 mm, operating at frequencies approximately ranging from 5 to 6 GHz, only enables to store a five-bit code. It should be noted that by increasing the operating frequency range, the tag size can be decreased. It would however be desirable to have chipless RFID cards having a greater storage capacity per surface area unit, for a given operating frequency range.
SUMMARY
[0014] Thus, an object of an embodiment of the present invention is to provide a chipless RFID tag at least partly overcoming some of the disadvantages of conventional chipless RFID tags.
[0015] An object of an embodiment of the present invention is to provide such a tag which is less expensive and easier to manufacture than conventional chipless RFID tags.
[0016] An object of an embodiment of the present invention is to provide such a tag that can be easily formed on any type of support, for example, by simple printing or screen printing of conductive tracks on a single surface of any type of package (for example, made of cardboard or paper).
[0017] An object of an embodiment of the present invention is to provide such a tag enabling to store more data per surface area unit than conventional chipless RFID tags.
[0018] Thus, an embodiment of the present invention provides a chipless RFID tag comprising a plurality of separate parallel conductive strips formed on a dielectric support, wherein conductive bridges interconnect neighboring conductive strips, the conductive bridges delimiting, between the conductive strips, portions of dielectric strips of different lengths, each dielectric strip portion determining a resonance frequency of the tag, the resonance frequencies of the tag altogether defining an identification code.
[0019] According to an embodiment of the present invention, a dielectric strip, not shorted by a conductive bridge, is arranged between each pair of neighboring conductive strips interconnected by a conductive bridge.
[0020] According to an embodiment of the present invention, all neighboring conductive strips are interconnected by conductive bridges.
[0021] According to an embodiment of the present invention, the width of a conductive strip comprised between two neighboring dielectric strips is at least equal to three times the width of the adjacent conductive strips.
[0022] According to an embodiment of the present invention, the conductive strips are U-shaped in top view.
[0023] According to an embodiment of the present invention, the conductive strips have the shape of portions of circles in top view.
[0024] According to an embodiment of the present invention, the conductive strips are rectilinear, pairs of neighboring strips having the same length and pairs of neighboring strips having different lengths.
[0025] According to an embodiment of the present invention, the portions of dielectric strips all have the same width.
[0026] Another embodiment of the present invention provides a method for coding data readable by an electromagnetic wave transceiver, comprising the steps of: forming a plurality of separate parallel conductive strips on a dielectric support; forming conductive bridges interconnecting neighboring conductive strips, so that the conductive bridges delimit, between the conductive strips, portions of dielectric strips of different lengths, each dielectric strip portion determining a resonance frequency; and associating with each resonance frequency a portion of the data.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] The foregoing and other objects, features and advantages of the present invention will be discussed in detail in the following non-limiting description of specific embodiments in connection with the accompanying drawings, among which:
[0028] FIG. 1 , previously described, very schematically illustrates a remote identification system in RFID technology;
[0029] FIG. 2 , previously described, is a perspective view schematically showing a chipless RFID tag;
[0030] FIG. 3 is a top view schematically showing an embodiment of a chipless RFID tag;
[0031] FIG. 4 is a top view schematically showing another embodiment of a chipless RFID tag;
[0032] FIG. 5 is a top view schematically showing another embodiment of a chipless RFID tag;
[0033] FIG. 6 schematically shows the power spectrum of the electromagnetic signal seen by a read terminal in the presence of the tag of FIG. 5 ;
[0034] FIG. 7 is a top view schematically showing three alternative embodiments of the tag of FIG. 5 ;
[0035] FIG. 8 schematically shows the superposition of the power spectrums of the electromagnetic signal seen by a read terminal in the presence of each of the tags of FIG. 7 ;
[0036] FIG. 9 schematically shows another embodiment of a chipless RFID tag; and
[0037] FIG. 10 schematically shows another embodiment of a chipless RFID tag.
DETAILED DESCRIPTION
[0038] For clarity, the same elements have been designated with the same reference numerals in the different drawings and, further, the various drawings are not to scale.
[0039] FIG. 3 is a top view schematically showing an embodiment of a chipless RFID tag 31 . Tag 31 is formed on a dielectric support 33 and supports conductive patterns on a single one of its two surfaces. Four separate parallel rectilinear conductive strips 35 a to 35 d are formed on this surface. Strips 35 a to 35 d are identical, aligned along a direction perpendicular to the strips, and spaced apart from one another by a same step. Thus, conductive strips 35 a to 35 d delimit three identical rectilinear dielectric strips 37 a to 37 c. Conductive bridges interconnect neighboring conductive strips to delimit, between the conductive strips, portions of dielectric strips of different lengths. In this example, two conductive bridges 38 a and 38 b respectively interconnect neighboring left-hand conductive strips 35 a and 35 b and neighboring right-hand conductive strips 35 c and 35 d. Thus, each of the left-hand and right-hand dielectric strips, respectively 37 a and 37 c, is divided into two portions of dielectric strips. The tag thus comprises four portions of dielectric strips of different lengths 39 a to 39 d. Central dielectric strip 37 b thus is not shorted by a conductive bridge.
[0040] Tag 31 forms a structure with resonant elements capable of interfering with an electromagnetic signal transmitted by an RFID read terminal (not shown). Each dielectric strip portion 39 a to 39 d is mainly surrounded with a U-shaped conductive path. Thus, each dielectric strip portion 39 a to 39 d defines an LC-type resonant circuit capable of retransmitting a specific electromagnetic wave which can then be detected by the read terminal. Inductance L especially depends on the length of the U-shaped conductive path, and thus on the length of the dielectric strip portion. The two parallel branches of the U-shaped conductive path, separated by the dielectric strip portion, form capacitance C. Thus, each dielectric strip portion 39 a to 39 d determines, by its length, a resonance frequency of tag 31 . The resonance frequencies of the tag altogether define an identification code. The tag identifier is thus especially determined by the length and/or the position of conductive bridges 38 a and 38 b.
[0041] According to an example of an RFID tag forming method, tags comprising the basic pattern created by the parallel conductive strips may be formed at a large scale, and the final user may be given the possibility of forming the conductive bridges by himself, for example, by printing with a conductive ink. An advantage of such a method is that it enables the final user to customize the identifiers of its tags.
[0042] Central dielectric strip 37 b, non-shorted by a conductive bridge, has the function of avoiding stray coupling phenomena between resonant regions of the tag. Thus, a modification of the length of a dielectric strip portion causes a modification of the resonance frequency associated with this strip portion, but has no influence upon the resonance frequencies associated with the other strip portions.
[0043] FIG. 4 is a top view schematically showing another embodiment of a chipless RFID tag 41 . Tag 41 is formed on a dielectric support 43 . On one surface of support 43 are formed three separate parallel rectilinear conductive strips 45 a to 45 c. Strips 45 a to 45 c are spaced apart from one another by a same step. Thus, conductive strips 45 a to 45 c delimit three identical rectilinear dielectric strips 47 a and 47 b. Conductive bridges interconnect the neighboring conductive strips to delimit, between the conductive strips, portions of dielectric strips of different lengths. In this example, two conductive bridges 48 a and 48 b respectively interconnect neighboring conductive strips 45 a and 45 b and neighboring conductive strips 45 b and 45 c. Thus, each of dielectric strips 47 a and 47 b is divided into two portions of dielectric strips of different lengths. The tag thus comprises four portions of dielectric strips of different lengths 49 a to 49 d. Unlike tag 31 of FIG. 3 , tag 41 does not comprise a central dielectric strip not shorted by a conductive bridge. Central conductive strip 45 b is provided to have a sufficient length, to avoid stray coupling phenomena between resonant slots of the tag. As an example, central strip 45 b has a width at least equal to three times the width of lateral strips 45 a, 45 c.
[0044] An advantage of RFID tags of the type described in relation with FIGS. 3 and 4 is that they are easier to manufacture than tags of the type described in relation with FIG. 2 . Indeed, unlike tag 21 of FIG. 2 , tags 31 and 41 of FIGS. 3 and 4 comprise no ground plane. Tags 31 and 41 may be formed, by deposition or by printing with a conductive ink, on a single surface of any dielectric support. Tags may in particular be formed directly on the objects which are desired to be tagged, for example, on food packagings.
[0045] FIG. 5 is a top view schematically showing a preferred alternative embodiment of a chipless RFID tag 51 . Tag 51 is formed on a dielectric support 53 . One surface of support 53 supports separate parallel conductive strips in the shape of interleaved Us. In this example, the tag comprises three conductive strips 55 a to 55 c, strips 55 a and 55 c respectively being the outer strip and the inner strip of the pattern. The strips are spaced apart from one another by a same step. The two parallel branches of the U formed by inner strip 55 c are spaced apart by a distance equal to the step separating strips 55 a to 55 c from one another. Thus, conductive strips 55 a to 55 c delimit two U-shaped dielectric strips, 57 a and 57 b, and a rectilinear dielectric strip 57 c, between the parallel branches of the U formed by strip 55 c. Conductive bridges 58 a and 58 b are formed on outer and inner dielectric strips, respectively 57 a and 57 c, thus delimiting three dielectric strip portions 59 a to 59 c of different lengths. To avoid stray coupling phenomena between resonant regions of the tag, central dielectric strip 57 b is not shorted by a conductive bridge.
[0046] Tag 51 forms a structure with resonant elements capable of interfering with an electromagnetic signal transmitted by an RFID read terminal (not shown). As in the case of the RFID tags described in relation with FIGS. 3 and 4 , each dielectric strip portion 59 a to 59 c determines, by its length, a resonance frequency of the tag. The tag resonance frequencies altogether define an identification code.
[0047] FIG. 6 schematically shows the spectrum of the electromagnetic signal seen by a read terminal in the presence of tag 51 of FIG. 5 . The spectrum comprises three lines 59 a to 59 c, respectively at frequencies on the order of 2.6 GHz, 2.2 GHz, and 4.4 GHz, respectively corresponding to the resonance frequencies linked to the dielectric strip portions having the same reference numerals. The shorter the length of a dielectric strip portion, the higher the associated resonance frequency. The read terminal can detect the presence of lines in the signal spectrum and determine the tag identification code. It should be noted that the spectrum peaks may also be used to code the identifier associated with the tag.
[0048] FIG. 7 , substantially identical to FIG. 5 , schematically shows tag 51 for three different identification codes. The three codes correspond to three different lengths 58 a 1 , 58 a 2 , 58 a 3 of conductive bridge 58 a, thus affecting the length of dielectric strip portion 59 a, as shown in dotted lines in the drawing. Dielectric strip portions 59 b and 59 c have the same length for the three codes.
[0049] FIG. 8 schematically shows the superposition of the power spectrums of the electromagnetic signal seen by a read terminal in the presence of each of the tags of FIG. 7 . When the length of dielectric strip portion 59 a varies, the position of the corresponding strip 59 a in the strip also varies. The spectrum superposition thus comprises three different strips 59 a 1 , 59 a 2 , and 59 a 3 , corresponding to the three different lengths of dielectric strip portion 59 a. According to an advantage of the present invention, a length modification of one of the dielectric strip portions has no influence upon the resonance frequencies associated with the other dielectric strip portions. Indeed, the spectrum superposition comprises a single line 59 b corresponding to the resonance frequency linked to dielectric strip portion 59 b and a single line 59 c corresponding to the resonance frequency linked to dielectric strip portion 59 c. As mentioned hereabove, the spectrum peaks may also be used to code the identifier associated with the tag.
[0050] It may be provided to associate one or several bits of an identification code with each dielectric strip portion. As an example, in the case of tag 51 ( FIGS. 5 and 7 ), it may be provided to associate three bits of an identification code with each dielectric strip portion 59 a to 59 c. Each portion 59 a to 59 c may then take one of eight different lengths corresponding to eight different resonance frequencies. It will of course be ascertained that there is no overlapping between resonance frequency ranges associated with different dielectric strip portions.
[0051] FIG. 9 schematically shows another alternative embodiment of a chipless RFID tag 91 . Tag 91 is similar to tag 51 of FIG. 5 , except for the fact that the parallel conductive strips have the shape of concentric circle portions. The tag has substantially the same operating principle as tag 51 .
[0052] An advantage of chipless RFID tags, U-shaped or in circle portions, of the type described in relation with FIGS. 5 and 9 , is that they enable to store more data per surface area unit than tags of the type described in relation with FIG. 2 . As an example, tag 51 of FIG. 5 enables to store a nine-bit identification code (three bits per dielectric strip portion) on a 17.5×15-mm rectangular surface, for an operating frequency range from 2 to 5 GHz. The tag surface area can be strongly decreased by using higher identification frequencies.
[0053] FIG. 10 is a top view schematically showing another alternative embodiment of a chipless RFID tag 101 . Tag 101 is formed on a dielectric support 103 . A surface of support 103 has parallel rectilinear conductive strips 105 a to 105 f formed thereon. Strips 105 a to 105 f have the same width and are spaced apart from one another by a same step. Pairs of neighboring strips have the same length. In the shown example, neighboring strips 105 a and 105 b have a first length, the next neighboring strips 105 c and 105 d have a second length greater than the first length, and the next neighboring strips 105 e and 105 f have a third length greater than the second length. Thus, conductive strips 105 a to 105 d delimit three rectilinear dielectric strips of different lengths 107 a to 107 c, respectively between conductive strips 105 a and 105 b, 105 c and 105 d, and 105 e and 105 f. Conductive bridges 108 a to 108 c are formed, each at one end of one of dielectric strips 107 a to 107 c, interconnecting conductive strips of same length. Actually, the configuration of FIG. 10 is similar to the configuration of FIG. 3 , with the difference that parallel conductive strips have different lengths and that the conductive bridges are formed at the end of the dielectric strips. Each dielectric strip defines a resonant circuit determining a resonance frequency of tag 101 . The resonance frequencies of the tag altogether define an identification code.
[0054] It may be provided to associate with each dielectric strip 107 a to 107 c a bit of an identification code or, as in the example described in relation with FIG. 7 , several bits of an identification code.
[0055] Specific embodiments of the present invention have been described. Various alterations, modifications, and improvements will readily occur to those skilled in the art.
[0056] In particular, chipless RFID tag patterns comprising three or four parallel conductive strips have been described hereabove in relation with FIGS. 3 , 4 , 5 , 9 , and 10 . The present invention is not limited to these specific examples. Patterns comprising a larger number of conductive strips may especially be provided.
[0057] Further, the possibility of associating three bits of an identification code to each dielectric strip portion has been mentioned. The present invention is not limited to this specific case. It may especially be provided to associate a larger number of bits with each dielectric strip portion. However, this will decrease the interval, in the electromagnetic signal spectrum, between two resonance lines corresponding to two different lengths of a same dielectric strip portion. A sufficiently sensitive read terminal should thus be provided.
[0058] Further, RFID tags 51 , 91 , and 101 , described in relation with FIGS. 5 , 9 , and 10 , comprise dielectric strips not shorted by conductive bridges to avoid stray coupling phenomena between the resonant regions of the tag. The present invention is not limited to this specific case. It may be provided to use all dielectric strips for the identification code storage, as in the case of tag 41 of FIG. 4 . It will then be ascertained to provide a sufficient distance between two dielectric strips to avoid stray coupling phenomena.
[0059] Further, in chipless RFID tags described in relation with FIGS. 3 , 4 , 5 , 9 , and 10 , all the dielectric strips delimited by parallel conductive strips have the same width. The present invention is not limited to this specific case. One may in particular have dielectric strips of different lengths on a same tag. Similarly, the parallel conductive strips may have different widths.
[0060] Further, although one of the advantages of chipless RFID tags provided hereabove is the possibility of doing away with any conductive ground plane, one may also, for certain uses, and especially in a metal environment, use patterns of the type described in relation with FIGS. 3 , 4 , 5 , 9 , and 10 in combination with a ground plane.
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A chipless RFID tag comprises a plurality of disjoint parallel conducting bands formed on a dielectric support, in which conducting bridges interlink neighboring conducting bands, the conducting bridges delimiting, between the conducting bands, portions of dielectric bands of distinct lengths, each portion of dielectric brand determining a resonant frequency of the tag, the set of resonant frequencies of the tag defining an identification code.
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This is a continuation of copending application Ser. No. 07/863,380 filed on Apr. 3, 1992, now abandoned. which is a continuation of application Ser. No. 07/725,947 filed Jun. 27, 1991 now abandoned, which is a continuation of Ser. No. 06/948,103 filed Dec. 31, 1986, now abandoned.
This invention is directed to an improved flame-retardant polycarbonate composition of an aromatic polycarbonate polymer in admixture with a flame retardant amount of a compound containing aromatically bound bromine, the composition including an epoxidized cycloaliphatic compound to retard dripping of flaming resin when articles molded from the composition are directly exposed to an open flame, especially after conditioning in humid environments
BACKGROUND OF THE INVENTION
In Mark, U.S. Pat. No. 4,110,299, flame-retardant polycarbonate compositions are disclosed wherein the flame retardant comprises an organic monomeric or polymeric aromatic or heterocyclic halide. Also described are such compositions containing from 0.01 to 2.0 weight percent of a fluorinated polyolefin, e.g., poly(tetrafluoroethylene) to retard dripping flaming resin when articles molded from such compositions are exposed to an open flame. Although such compositions represent the current state of the art, dripping can still be a problem, especially in such impact modified compositions, particularly if the impact modifier is an acrylate polymer or copolymer, such as a copolymer of ethylene and ethyl acrylate.
Also showing the current state of the art is Rosenquist, U.S. Pat. No. 4,579,896, which discloses flame retardant and drip retardant polycarbonate compositions comprised of an aromatic carbonate resin, a flame retardant compound and a bis cyclic carbonate drip retardant.
In Calkins, U.S. Pat. No. 3,489,716 are disclosed aromatic polycarbonate resin compositions which do not include a flame retardant additive, but which are rendered color stable at elevated temperatures by adding 0.01 to 0.5 weight percent of an epoxidized cycloaliphatic compound. In Factor, U.S. Pat. No. 3,673,146, are disclosed color tinted polycarbonate compositions which do not increase in yellowness when remolded because they contain a small amount of a cycloaliphatic epoxy compound. In neither Calkins nor Factor is there any hint or suggestion that epoxidized cycloaliphatic compounds will function as drip-retarding agents in flame-retardant compositions.
It has now surprisingly been found that epoxidized cycloaliphatic compounds can be employed alone or together with other additives to render flame-retardant polycarbonate compositions free of any tendency after molding to drip flaming resins when exposed to an open flame, and exposure to humidity, and this discovery is the subject matter of the present invention.
SUMMARY OF THE INVENTION
In accordance with the present invention there are provided flame retardant aromatic polycarbonate compositions which do not drip flaming resin when exposed to an open flame, said compositions comprising:
(a) a polycarbonate resin of a dihydric phenol;
(b) an effective flame retardant amount of a compound containing aromatically bound bromine; and
(c) from 0.01 to 0.50 weight percent of an epoxidized cycloaliphatic compound containing:
(i) 1-2 cycloaliphatic rings of six carbon atoms each, with at least one oxygen bridge being attached to adjacent carbon atoms in at least one cycloaliphatic ring;
(ii) 6 to 30 carbon atoms; and
(iii) only carbon, hydrogen and oxygen.
Also contemplated are compositions as defined above which also include
(d) an impact improving amount of an acrylate impact improver.
In preferred features polycarbonate resin (c) comprises poly(bisphenol-A carbonate); the compound containing aromatically bound bromine (b) comprises a copolycarbonate compound, i.e., carbonate copolymer comprised of units derived from tetrabromobisphenol-A and bisphenol-A, preferably in a mole ratio of the former to the latter of approximately from about 1:2.2 to about 1:3; and the epoxidized cycloaliphatic compound (c) comprises 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate.
DETAILED DESCRIPTION OF THE INVENTION
In the practice of this invention, any of the aromatic polycarbonates can be employed herein having a refractive index in the range of 1.54 to 1.65. These are homopolymers and copolymers and mixtures thereof that are prepared by reacting a dihydric phenol with a carbonate precursor. Typical of some of the dihydric phenols that may be employed in the practice of this invention are bisphenol-A, (2,2-bis(4-hydroxyphenyl) propane), bis(4-hydroxyphenyl) methane, 2,2-bis(4-hydroxy-3-methylphenyl) propane, 4,4-bis(4-hydroxyphenyl) heptane, and the like. Other dihydric phenols of the bisphenol type are also available and are disclosed in U.S. Pat. Nos. 2,999,835, 3,028,365 and 3,334,154.
It is, of course, possible to employ two or more different dihydric phenols or a copolymer of a dihydric phenol with a glycol or with hydroxy or acid terminated polyester, or with a dibasic acid in the event a carbonate copolymer or interpolymer rather than a homopolymer is desired for use in the preparation of the aromatic carbonate polymers of this invention. Also employed in the practice of this invention may be blends of any of the above materials to provide the aromatic carbonate polymer.
The carbonate precursor may be either a carbonyl halide, a carbonate ester or a haloformate. The carbonyl halides which can be employed herein are carbonyl bromide, carbonyl chloride and mixtures thereof. Typical of the carbonate esters which may be employed herein are diphenyl carbonate, di-(halophenyl) carbonates such as di-(chlorophenyl) carbonate, di-(bromophenyl) carbonate, di-(trichlorophenyl) carbonate, di-(tribromophenyl) carbonate, etc., di-(alkylphenyl) carbonate such as di(tolyl)carbonate, etc., di-(naphthyl) carbonate, di-(chloronaphthyl) carbonate, phenyl tolyl carbonate, chlorophenyl chloronaphthyl carbonate, etc., or mixtures thereof. The haloformates suitable for use herein include bis-haloformates of dihydric phenols (bischloroformates of hydroquinone), etc.) or glycols (bishaloformates of ethylene glycol, neopentyl glycol, polyethylene glycol, etc.). While other carbonate precursors will occur to those skilled in the art, carbonyl chloride, also known as phosgene, is preferred.
Also included are the polymeric derivatives of a dihydric phenol, a dicarboxylic acid and carbonic acid. These are disclosed in U.S. Pat. No. 3,169,121 which is incorporated herein by reference.
The aromatic carbonate polymers of this invention may be prepared by employing a molecular weight regulator, an acid acceptor and a catalyst. The molecular weight regulators which can be employed in carrying out the process of this invention include monohydric phenols such as phenol, chroman-I, paratertiarybutylphenol, parabromophenol, primary and secondary amines, etc. Preferably, phenol is employed as the molecular weight regulator.
A suitable acid acceptor may be either an organic or an inorganic acid acceptor. A suitable organic acid acceptor is a tertiary amine and includes such materials as pyridine, triethylamine, dimethylaniline, tributylamine, etc. The inorganic acid acceptor may be one which can be either a hydroxide, a carbonate, a bicarbonate, or a phosphate of an alkali or alkaline earth metal.
The catalysts which are employed herein can be any of the suitable catalysts that aid the polymerization of bisphenol-A with phosgene. Suitable catalysts include tertiary amines such as, for example, triethylamine, tripropylamine, N,N-dimethylaniline, quaternary ammonium compounds such as, for example, tetraethylammonium bromide, cetyl triethyl ammonium bromide, tetra-n-heptylammonium iodide, tetra-n-carbonate propyl ammonium bromide, tetramethylammonium chloride, tetramethyl ammonium hydroxide, tetra-n-butylammonium chloride, benzyltrimethylammonium chloride and quaternary phosphonium compounds such as, for example, n-butyltriphenyl phosphonium bromide and methyl-triphenyl phosphonium bromide.
Also, included herein are branched polycarbonates wherein a polyfunctional aromatic compounds is reacted with the dihydric phenol and carbonate precursor to provide a thermoplastic randomly branched polycarbonate.
These polyfunctional aromatic compounds contain at least three functional groups which are carboxyl, carboxylic anhydride, haloformyl or mixtures thereof. Examples of these polyfunctional aromatic compounds which may be employed in the practice of this invention include: trimellitic anhydride, trimellitic acid, trimellitic trichloride, 4-chloroformyl phthalic anhydride, pyromellitic acid, pyromellitic dianhydride, mellitic acid, trimesic acid, benzophenonetetracarboxylic acid, benzophenonetetracarboxylic anhydride and the like. The preferred polyfunctional aromatic compounds are trimellitic anhydride or trimellitic acid, or their haloformyl derivatives.
Also, included herein are blends of a linear polycarbonate and a branched polycarbonate.
The organic bormines (b) are used in amounts of from 0.10 to about 10.0 parts per hundred parts of aromatic carbonate polymer.
Illustrative organic bromines include decabromodiphenyl phenyl ether; bis(pentabromophenoxy) ethane; decabromodiphenyl carbonate; and tetrabromo-BPA-polycarbonate "BPA" being bisphenol A.
Special mention is made of an aromatic carbonate copolymer, i.e., copolycarbonate in which from 25 to 75 wt. percent of the repeating units comprise bromo-substituted dihydric phenol units and the remainder of the repeating units comprise dihydric phenol, glycol or dicarboxylic acid units. The aromatic carbonate copolymers, i.e., copolycarbonate can be prepared by any of the well known methods which, for example, include reacting such materials as tetra-bromobisphenol-A, also known as 2,2-bis-(3,5-dibromo-4hydroxyphenyl)propane, e.g., ethylene glycol or propylene glycol or a dicarboxylic acid, e.g., adipic acid or isophthalic acid, but preferably a dihydric phenol such as bisphenol-A, also known as 2,2-bis(4-hydroxyphenyl)propane, with phosgene or a reactive derivative of phosgene.
Preferably, the carbonate copolymer modifier, i.e., copolycarbonate employed to provide the moldable flame-resistant polycarbonate resin-containing compositions of the present invention will be a copolymer prepared by reacting 75-25 wt. percent and preferably 40-30 wt. percent of tetra-bromobisphenol-A and correspondingly, 25-75 and preferably 60-70 wt. percent of another compound which may be either a dihydric phenol, a glycol or a dicarboxylic acid or mixtures thereof, said weights being based on the total weight of the copolymer. In addition, the aromatic carbonate copolymer, i.e., copolycarbonate should have an intrinsic viscosity of 0.2-0.7 deciliters/gram, as measured, for example, in p-dioxane at about 30° C. Typical examples of the other compounds which can be employed in place of the bisphenol-A component of the copolymer are other dihydric phenols such as hydroquinone, resorcinol, 2,2-bis(4-hydroxyphenyl)pentane, 2,4'-dihydroxydiphenylmethane, 2,6-dihydroxynaphthalene, bis-(4-hydroxyphenyl)sulfone, 4,4'-dihydroxydiphenyl ether, etc.; or glycols, such as ethylene glycol, propylene glycol, tetramethylethylene glycol, etc.; and also dicarboxylic acids such as adipic acid, isophthalic acid, sebacic acid, etc.; as well as mixtures of any of the above. However, the preferred copolymer component for use in the practice of this invention is a copolymer of about 35 wt. percent of tetrabromobisphenol-A and 65 wt. percent of bisphenol-A, respectively.
Component (c) herein is an epoxidized cycloaliphatic compound containing 1-2 cycloaliphatic rings of six carbon atoms each with at least one oxygen bridge being attached to adjacent carbon atoms in at least one cycloaliphatic ring. The amount of epoxidized cycloaliphatic compound employed herein can range anywhere from 0.01-0.50 weight percent based on the weight of the total composition.
In general, any of the epoxidized cycloaliphatic compounds having the above limitations can be employed in the practice of this invention. In place of the 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexane carboxylate used in the example, the following compounds produce essentially the same results, which compounds are: 3,4-epoxy-6-methylcyclohexylmethyl 3,4-epoxy-6-methylcyclohexane carboxylate, 2,3-epoxycyclohexylmethyl 3,4-epoxycyclohexane carboxylate, 4-(3,4-epoxy-5-methylcyclohexyl) butyl 3,4-epoxycyclohexane carboxylate, 3,4-epoxycyclohexylethylene oxide, di-3,4-epoxy-6-methylcyclohexyl-methyl adipate, cyclohexylmethyl 3,4-epoxycyclohexane carboxylate and 3,4-epoxy-6-methylcyclohexylmethyl 6-methylcyclohexyl carboxylate. In the practice of this invention the epoxidized cycloaliphatic compound can contain anywhere from 6 up to 30 carbon atoms. Preferably, however, in the practice of this invention, the preferred epoxidized cycloaliphatic compound is 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexane carboxylate.
As has been mentioned, component (d) can be used in conjunction with an organic polymer or polymers, for example, acrylate copolymers, such as olefin-alkyl acrylate or methacrylate copolymers containing a minor proportion of the acrylate or methacrylate, e.g., from 1 to 25 mol percent. Preferably, ethylene-ethyl acrylate copolymers will be used, such as those containing about 8 to 12% by weight of acrylate units. A typical commercial source is Dow Chemical Co. DPD 6169. Conventional amounts are used, e.g., 1 to 8 percent.
Other suitable acrylate polymers are acrylate-based core-shell multi-phase composite interpolymer resins. More particularly, the acrylate-based core-shell multi-phase composite interpolymer resin is a core-shell interpolymer comprising about 25 to 95/percent by weight of a first elastomeric phase and about 75 to 5 percent by weight of a final rigid thermoplastic shell phase. One or more intermediate phases are optional, for example, a middle stage polymerized from about 75 to 100 percent by weight styrene. An interpolymer of this type is commercially available under the tradename, ACRYLOID® KM 330, from Rohm & Haas Chemical Company. Also useful would be ACRYLOID® KM653 which has a polybutadiene core and acrylate shell.
The compositions of this invention are prepared by admixing the aromatic carbonate polymer with the organic halides (b) and the epoxidized cycloaliphatic compounds (c) and, optionally, impact modifier (d).
The compositions of the invention may also contain fillers, pigments, dyes, antioxidants, stabilizers, ultraviolet light absorbers, mold release agents and other additives commonly employed in non-opaque polycarbonates resin formulations. Furthermore, the shaped articles may be coated with, for example, mar- or scratch-resistant coatings.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In order to more fully and clearly illustrate the present invention, the following specific examples are presented. It is intended that the examples be considered as illustrative rather than limiting the invention disclosed and claimed herein. In the examples, all parts and percentages are on a weight basis unless otherwise specified.
GENERAL PROCEDURE
One hundred (100) parts of an aromatic polycarbonate, prepared by reacting 2,2-bis[4-hydroxyphenyl)propane and phosgene in the presence of an acid acceptor and a molecular weight regulator and having an intrinsic viscosity of 0.57 is mixed with the amounts of additives to be specified either singly or in combination by tumbling the ingredients together in a laboratory tumbler. The resulting mixture is then fed to an extruder, operated at about 280° C., and the extrudate is comminuted into pellets.
The pellets are then injection molded at about 275° C. into test bars of about 5 in. by 1/2 in. by about one-sixteenth in. thick. The test bars (5 for each additive listed in the Table) are subject to the test procedure set forth in Underwriters' Laboratories, Inc. Bulletin UL-94, Burning Test for Classifying Materials.
In this test, an open flame is applied to each specimen for 10 seconds, removed until all flaming or glowing ceases, then the flame is re-applied for an additional ten seconds. Thus each specimen receives two applications of the flame. That is 10 applications of flame will be applied for a total of 5 specimens.
In accordance with this test procedure, materials so investigated are rated either V-O, V-I or V-II based on the results of 5 specimens. The criteria for each V (for vertical) rating per UL-94 is briefly as follows:
"V-O": Average flaming and/or glowing after removal of the igniting flame shall not exceed 5 seconds and none of the specimens shall drip flaming particles which ignite absorbent cotton.
"V-I": Average flaming and/or glowing after removal of the igniting flame shall not travel vertically for more than one-eighth inch of the specimen after flaming ceases and glowing is incapable of igniting absorbent cotton.
"V-II": Average flame and/or glowing after removal of the igniting flame shall not exceed 25 seconds and the specimens drip flaming particles which ignite absorbent cotton.
In addition, a test bar which continues to burn for more than 25 seconds after removal of the igniting flame is classified, not by UL-94, but by the standards of the instant invention, as "burns". Further, UL-94 requires that all test bars in each test group must meet the V type rating to achieve the particular classification. Otherwise, the 5 bars receive the rating of the worst single bar. For example, if one bar is classified as V-II and the other four (4) are classified as V-O, then the rating for all 5 bars is V-II.
The results of the different additives within the scope of the instant invention are as follows with a control being the aromatic polycarbonate as prepared above without the additives of the type set forth herein.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following examples illustrate the compositions of the present invention and provide data to show their advantages over the prior art. They are not intended to be construed to limit the claims in any manner whatsoever.
In the Examples and Tables that follow, the following abbreviations are used:
LEXAN--poly(bisphenol A carbonate)
TONE--polycaprolactone (plasticizer)
ERL--cycloaliphatic epoxy
STB--sodium trichlorobenzene sulfonate
EXAMPLES 1-2
Using the General Procedure hereinbefore described, materials were prepared and tested for flame retardancy. Compositions and test results are set forth in Table 1:
TABLE 1______________________________________Flame Retardant Compositions Example 1A* 1 2______________________________________Compositions (parts by weightLEXAN ® 141-111.sup.a 60 60 60LEXAN ® 145-111.sup.b 15 15 15LEXAN ® 105B.sup.c 25 25 25LEXAN ® R506.sup.d 0.75 0.75 0.75TONE ® 300.sup.e -- 7 7TONE ® 700 7 -- --STB.sup.f 0.80 0.80 0.80ERL ® 4221.sup.g -- 0.50 0.05PropertiesUL-94 Vertical Burn Test 1/16",48 hrs @ 50% RHVO Yes Yes YesAvg Flame-Out Time (FOT) 16 20 14(10 applications)No. Drips/10 bars 3 1 1No. Ignitions/10 bars 0 0 0UL-94 Vertical Burn Test 1/16"7 days @ 70° C.VO Yes Yes YesAvg. FOT (10 applications) -- 13 11No. Drips/5 bars -- 0 0No. Ignitions/5 bars -- 0 0______________________________________ .sup.a LEXAN ® 141-111, poly(bisphenolA carbonate), General Electric Company .sup.b LEXAN ® 145-111, powder poly(bisphenolA carbonate), General Electric Company .sup.c LEXAN ® 105B, brominated polycarbonate flame retardant, Genera Electric Company .sup.d LEXAN ® R506, General Electric Company .sup.e TONE ® 300 and TONE ® 700, polycaprolactone, i.v.'s, 0.3 and 0.7 dl./g., Union Carbide Company .sup.f STB, sodium trichlorobenzene sulfonate .sup.g ERL 4221, 3,4epoxycyclohexyl-3,4-epoxycyclohexane carboxylate, Union Carbide Company
The above data indicate that when tested for flammability in the Underwriters Laboratories Vertical Burn Test UL-94, the composition self-extinguished in less than 10 seconds and did not drip flaming resin (rating V-O).
EXAMPLES 3-7
Using the General Procedure hereinbefore described, materials were prepared and tested for flame retardancy. Compositions and test results are set forth in Table 2:
TABLE 2______________________________________Flame Retardant Compositions Example 3A* 3 4 5 6 7______________________________________Compositions(parts by weightLEXAN ® 141-111 60 60 60 60 60 60LEXAN ® 145-111 15 15 15 15 15 15LEXAN ® 105B 25 25 25 25 25 25LEXAN ® R506C 0.75 0.75 0.75 0.75 0.75 0.75TONE ® 300 7 7 7 7 7 7STB 0.80 0.80 0.80 0.80 -- 0.80ERL ® 4221 -- 0.20 0.10 0.05 0.05 0.05PropertiesUL-94 Vertical Burn Test1/16", 48 hrs @ 50% RHVO No No Yes Yes Yes YesAvg Flame-Out Time 22 18 14 18 16 16(FOT) (10 appl)No. Drips/10 bars 5/5 3/6 1 2 4 2No. Ignitions/10 bars 2/5 2/6 0 0 0 0______________________________________ *Control
The above-mentioned patents, publication and test methods are incorporated herein by reference.
Many variations will suggest themselves to those skilling in the art in light of the above, detailed description. For example, other additives known to those skilled in the art may be added in conventional amounts to the flame retardant compositions herein including but without limitation, 20 weight percent reinforcing glass fibers, 40 weight percent of poly(1,4-butylene terephthalate), 20 weight percent of talc or mica, and the like.
All such obvious variations are within the full intended scope of the appended claims without departing from the spirit of the invention.
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An improved flame-retardant composition comprises an aromatic carbonate polymer in admixture with a flame retardant amount of a compound containing aromatically bound bromine, which composition includes an epoxidized cycloaliphatic compound to retard dripping of flaming resin when articles molded from the composition are directly exposed to an open flame, especially after exposure to a humid atmosphere.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of the filing date of Chilean patent application Serial Number 0058-2005, filed Jan. 13, 2005 whose entire disclosure is hereby incorporated by reference.
FIELD
The invention relates to drop or false ceilings, in particular, a ceiling composed of ceiling tiles supported by a metal grid.
BACKGROUND
Grid supported ceiling panels are very common in the office buildings where ceilings are constructed over open floor plan interior designs, such as cubicles. Such ceiling are popular in other commercial, industrial and domestic environments, including and not limited to hotels, meeting rooms, recreation rooms and other types of rooms or constructions which require removable ceilings for access to utilities (heating, air conditioning, water) that are concealed in the space between the drop ceiling tiles and the structural ceiling of the room. Such ceiling systems are well suited for use in old office buildings with high ceilings and with ceilings that are curved or arched, especially barrel vault ceilings. However most conventional suspended ceiling systems have T-shaped grid members and those members are usually exposed to view from the room.
At least one system exists which provides a ceiling panel that is installed from beneath the support grid and partially covers the exposed grid members but leaves exposed a border of approximately 6 mm (for example the Hunter Douglas system). However that system is supported in only one direction, in other words, on two of the four sides. This renders it very unsafe. When a building is shaken by an earth tremor such ceiling panels may dislodge from the support grid and fall upon and injure people or damage property. To prevent damage and injury from falling panels, such systems are often sold with safety clips that retain the panels in the support grid in case it falls and leaves it hanging from the safety clip but out of position. The installation of such safety clips must be very precise because even a small variation in its position renders it inoperative. In addition, movement of the support grid between the moment panel first calls out of the grid and before the safety clip restrains it (e.g. another tremor) may cause the clip to fail and let the panel fall.
Panels for such systems are often made of from a clad particle agglomerate (solid) of approximately 16 mm with a weight of approximately 9.8 kg/m 2 , implying that the panel of approximately 610×610 mm weighs approximately 3.64 kg. That is a very heavy and potentially unsafe weight when one considers that the panel is suspended above the heads of the people who live or work beneath the panels or occupy or travel through a room and that has a ceiling made of such panels. Since the prior art panels are supported on only two of their four sides, they are vulnerable to deformation because gravity is always acting on the two free sides. The weight of the panel augments the action of gravity, thereby causing the panel to deform and lose its precise retention measurements.
There is another type of ceiling panel which is a bent metal sheet hung from a support grid that has several clamps at its lower part. The bent part has a vertical shape and carries some embossing that projects from the edge for the purpose of keeping the panels secured by the clamps. That system is much more expensive than the one described above and has weight limitations, given that the design is based on the elastic strength of the steel being greater than that required for the panel to fall under gravity. In addition the system only retains the panel on two sides. When a lighting fixture is contained within the panels, the weight of the fixture deforms them.
SUMMARY
The invention relates to a removable ceiling panel. It has a rectangular shaped ceiling panel made from a suitable material with a face, a back and four sides with edges. The ceiling panel is installed from beneath the plane of the support grid and is retained horizontally in the support grid by the cooperation of the stepped perimeter of the panel with members of the flanges of the support grid.
The ceiling panel conceals the support grid. The panel is supported at its four sides and it is retained in the suspended support grid in the vertical direction by gravity. The support grid is a standard type known in the market. The design of the sides of the panel permits easy and rapid installation of the ceiling panel by following a series of defined steps. Those steps provide a procedure for installation which also forms part of the invention. The installation steps are not natural and, consequently, render the panels resistant to dislodgment during an earthquake and thus they are aseismic.
The removable modular drop ceilings are also used to cover an unsightly ceiling of a room. It provides not only an esthetically acceptable ceiling cover but also retains access to any utilities installed above the drop ceiling. However, the presence of the rectangular supporting framework with its exposed profiles detracts from the appearance of the ceiling and makes it impossible to have a ceiling which resembles a single surface with a continuous and unbroken appearance. This invention provides a new ceiling tile panel that eliminate these visual breaks, provides continuity for the ceiling, it being interlocking with the support grid, esthetic, aseismic, safe, economic and easily installable.
The field of application of the invention is the entire spectrum of ceilings which are currently installed using ceiling panels which leave exposed portions of the support grid. The invention may be used with for new ceiling installations and for replacement installations where standard support grids have been previously installed.
The invention solves one or more technical problems including concealing the profile of the support grid, making installation easy by installing the panels from below the plane of the support grid and offering improved aseismic performance by retaining the panel in place by its four sides.
The elements constituting the panel are any suitable ceiling panel material having planar characteristics (for example: approximately 1215×605×15 mm), with the suitable properties of weight, rigidity, resiliency, aesthetics and the ability to be machined so a desired shape including a special edge and grooves, that permit its installation and help conceal the profile of the support grid.
The invention provides a ceiling panel for placement in a support grid hung from a structural ceiling. Each ceiling panel is a rectangular substrate with a face on one surface and back on the other surface. The substrate has a stepped edge that may be made by a router or by building the panel in laminated layers. The stepped edge is around the perimeter of the substrate and it has a first boundary for the face, a second boundary for a deep groove, a third boundary for a shallow groove and a fourth boundary for the back. The panel has an opening between the deep groove and the back surface. In one embodiment the opening is a diagonal groove disposed between the deep groove and the back surface. In another embodiment the opening is a recess in the back extending into the deep groove. In both embodiments the opening allows flanges on the support grid members to pass through the deep groove to the back side of the panel. Then the panel is manipulated to secure it in place so that the panel is supported on four sides in its shallow groove by the flanges of the grid supports.
In addition the panels have some recesses in the perimeter of their faces allowing the bearing level to be lower by approximately nine millimeters with respect to the plane of the grid support, thereby generating a design with greater visual volume.
DESCRIPTION OF THE DRAWINGS
FIG. 1 : Perspective view of a removable ceiling panel which conceals the retaining grid, having a cutout recess 3 , one short side 1 and one long side 2 . The upper part of the drawing corresponds to the back ( 22 ) that faces the structural ceiling.
FIG. 2 : Perspective view of the location of two panels on the retaining grid 4 so as to show the resulting borders 5 which conceal the grid.
FIG. 3 : Plan view of the retaining structure of a standard support grid seen from below.
FIGS. 4 a , 4 b , 4 c:
FIG. 4 a is side view of the short side of a panel with a length 8 generally of 586 mm.
FIG. 4 b is a side view of the long side 9 of the panel, generally of 1196 mm.
FIG. 4 c shows details of the final location of the panels in the profiled grid showing the back (upper) side ( 10 ) and the face (lower) side ( 11 ). On the opposite side is shown the deep groove edge 15 ( 25 d ) and the shallow groove 16 ( 25 s ).
FIGS. 5 a , 5 b , 5 c:
FIG. 5 a is a plan view of the back side 10 of a panel and its cutout recesses 3 . FIGS. 5 b and 5 c are side views of the panel.
FIGS. 6 a , 6 b:
FIG. 6 a shows a perspective view of the diagonal installation of a panel on flanges of the support grid 4 and an explanatory profile view FIG. 6 b of the recess 3 that receives the retaining profile.
FIG. 7 : Plan view of the panel seen from above, describing step 1 of installation.
FIG. 8 : Plan view of the panel seen from above, describing step 2 of installation.
FIG. 9 : Plan view of the panel seen from above, describing step 3 of installation.
FIG. 10 : Plan view of the panel seen from above, describing step 4 of installation.
FIG. 11 : Plan view of the panel seen from above, describing step 5 of installation.
FIG. 12 : Plan view of the panel seen from above, describing step 6 of installation.
FIG. 13 : Partial view of the stepped edge of a panel. The thickness of the panel is approximately 18 mm ( 14 ). Commencing from the vertex of the face ( 11 ) to the back ( 10 ) it comprises four boundaries as a function of the design of the groove being of approximately 4 mm, 7 mm, 3 mm and 4 mm ( 12 ). Taking the vertex of the face as the origin, the design of the edge has three boundaries, forming the greatest depth of the groove 25 d , being of approximately 6 mm, 5 mm and 8 mm ( 13 ).
FIG. 14 : is a plan view of the back 10 of a panel with measurement details.
FIGS. 14 b and 14 c show, respectively, the a short side 8 of approximately 605 mm, a long side 9 of approximately 1215 mm and a recess 3 of approximately 300 mm in length ( 16 ) by 19 mm in width ( 15 ).
FIGS. 15 a , 15 b : Shows details of an alternate embodiment.
DETAILED DESCRIPTION
Removable, false or drop ceiling panels are a common solution for covering top surfaces of rooms. Such ceilings hide or conceal everything which is installed between said ceiling and the structural top of the room, including and not limited to concealing electrical, water, air conditioning installations, firefighting systems, etc, and the slab of the floor above the room. The installation of these panels is carried out by means of a continuous support grid in the form of an inverted T which is hung from the slab or other structural ceiling, or equivalent, by means of wires or other members designed for this purpose. See FIG. 3 A typical grid has a first set of parallel support members 91 , 92 , 93 with an inverted T shape that are separated from one another by a distance of approximately 610 mm, the typical width of a ceiling panel. A second set of support members 81 , 82 , 83 also having an inverted T shape hung transverse to the first set. The second set of cross members is separated by the typical length of a ceiling panel, e.g. approximately 1200×610 and/or 610×610 mm between axes is assembled. The whole of this design is supported on its ends by angle support members 101 - 104 that run round the entire perimeter. The width of the lower exposed part of the angular support member is approximately 24 mm. Into this mesh of rectangular or square openings are installed ceiling panels of mineral fiber of approximately 605×1215 mm and/or 605×605 mm with different designs. The support grids are of enameled and/or galvanized steel of approximately 0.8 mm in thickness.
The standard retaining structure comprises metal elements in the shape of an inverted T which comprise a framework of support members which provide a rectangular array of spaces of approximately 1220×610 mm or 610×610 mm between axes, with an exposed profile width of approximately 24 or 16 mm. As an example we shall take that of the larger dimensions ( FIG. 3 ). This leaves an approximate free distance between the edges of the profile of 1196×586 mm.
Turning to FIGS. 1 , 5 , the invention is a rectangular ceiling tile or panel 20 with a face 21 which remains exposed and has the greatest perimeter and area, a back 22 with at least one partial cutout recess 3 on one of its sides. The face 21 has four sides or edges, 1 af , 1 bf , 2 af , and 2 bf . The back 22 also has four sides or edges l ab , 1 bb , 2 ab , and 2 bb . Grooves 25 s and 25 d run around the perimeter of the panel 20 between the front and back edges. The groove 25 d is deeper than grove 25 s ( FIGS. 4 , 13 ). The depth range of the two grooves is approximately 3 mm to 6 mm for the shallow groove 25 s and approximately 13 mm to 20 mm for the deep groove 25 d . A partial cutout recess 3 in the back 22 projects into the surface of the back 22 until reaching the groove 25 d which is the deeper of the two grooves. See FIGS. 1 , 4 and 5 . In other words, the panel has a face 21 that has a surface area greater than the surface area of the back 22 . The larger face 21 is adjacent deep groove 25 d and the smaller back 22 is adjacent shallow groove 25 s.
The sides or edges of the face 21 and back 22 of the panel 20 are longer at the respective free sides which project from the retaining structure 30 . See FIG. 4 and note how the distances 10 and 11 along one back and face edge are longer than the distances 8 , 9 between the support members 31 , 32 . The panel 20 has stepped edges as shown in FIG. 13 . The panel 20 may be made of multiple members laminated together to provide the stepped edges. As an alternative, the panel may be made of a single substrate that is routed on its edges to provide the stepped profile where the lateral boundary of the face is longest, the lateral boundary of the back in next in length, followed in decreasing order by the shallow groove 25 s and the deep groove 25 d . Note that the boundary of the face edge 11 is longest. Above it is the boundary of the deeper groove 25 d . Next is the boundary of the shallow groove 25 s and finally the boundary of the back edge 10 . The back edge 10 is shorter than the face edge 11 and forms a wall of the shallow groove 25 s . The deep groove 25 d is disposed between the face 21 and the wall 25 w of the shallow groove 25 s.
The width of the face 21 is chosen to be approximately half the distance between spaced apart grid support members. In this way, faces of adjacent panels will register or abut each other to provide a continuous surface unbroken by support grids. See, for example, FIG. 4 c where length 11 of the face is long enough to overlap about half the width of the support members 31 , 32 . Note also how the deep groove 25 d is shorter than the width between flanges 31 , 32 , how the length of the shallow groove 25 s is about the same as the distance between flanges and the how the length 10 of the back is long enough to overlap a portion (but less than half) of the width of the flanges 31 , 32 . Once the panel 20 is installed, the stepped edge of the panel securely holds the panel 20 in the grid space and on the flanges. This renders it almost impossible for random motion such as caused by an earthquake to cause the panel to enter or leave this structure once it has been installed.
In order for the panel 20 to enter or exit a space in the assembled support grid structure, the panel has a partial cutout recess 3 on at least one side. In a preferred embodiment the recess 3 is disposed on the two short sides 1 ab , 1 bb . The recess 3 is large enough to permit a flange 4 of one of the support members of the structure to enter the stepped edge diagonally at the bottom of the deep groove 25 d and leave one corner of the back on the flange of the grid and the other under the grid. See FIGS. 6 a , 6 b . As will become clear for the following explanation, the recess 3 provides an opening for sliding a flange of a support member from the deep groove 25 d to above the back 22 of the panel. Once the panel 20 is in place, a motion caused by an earthquake would be insufficient to remove the panel.
Given the design of the ceiling panel 20 , its installation is carried out in accordance with the procedure subject of this patent and which comprises the following steps:
Step 1. Raise the panel 20 with its face 21 down and level with the grid. See FIG. 7 . The back 22 of the panel has two short sides 1 ab , 1 bb , and two long sides 2 ab , 2 bb . The sides meet in corners 41 , 42 , 43 , 44 . The support members included flanges 51 , 52 , 53 , 54 that project into the rectangular space defined by the support grid members. Step 2. Fit the panel diagonally to short side 1 bb , with the recess 3 , so that the flanges 51 is introduced into the portion of deep groove 25 d from the corner 44 to the recess, leaving the lower end of the flange 51 over the portion from the recess to the corner 43 . The panel stay in an angle and slide over the upper end of flanges 51 , 52 to leave corners 42 , 43 under the lower end of flanges 51 , 52 . See FIGS. 6 b , 8 . Step 3. Displace the panel 20 in the direction shown by arrow 60 in FIG. 8 . This direction is parallel to the support flanges 51 , 52 and in the direction of the higher corners 41 , 44 . Move panel 20 until the flange 53 of the support member is fully introduced into the deeper groove 25 d of the long side 2 bb , such that the panel 20 has one side 2 bb and its corners 41 , 44 fitted into the deep groove thus leaving the opposite side 2 ab free with respect to the back and the flange 54 . See FIG. 9 . Step 4. Raise the free corner 42 opposite the fitted corner 44 until the panel 20 is level on those sides with respect to the flanges of the profile. This step is fundamental in order that the result be aseismic and is an operation which it would be difficult for nature to carry out. This is because the step deforms both the panel 20 and the support grind structure. The deformation is caused by the lever effect which is applied to the free corner 42 , with respect to the fitted side 2 bb and the diagonal fitted section of the side 1 bb . The panel 20 or the support members or both are resilient and return to their normal shape after the small deformation needed to set the panel in place in the grid. Once leveled, the panel is slid parallel to the fitted long side until the free short sides 1 ab are fully introduced into the deep groove 25 d . In this manner the short sides which are fitted diagonally are freed and the lever is completed. See FIG. 10 . Step 5. Raise the free corners 43 opposite the fitted corners 41 until the panel 20 is level on those sides with respect to the flanges of the profile. Displace the panel in the direction of arrow 62 and parallel to the long side toward the free short side 1 ab until it is supported by the shallow groove 25 s . As a result the projecting side is also supported by its shallow groove. At this point the panel is supported by two shallow groves 25 s on its short sides 1 ab , 1 bb and by a deep groove 25 d on one long side 2 bb . See FIG. 11 . Step 6. Displace the panel in the direction of arrow 63 toward the free long side 2 ab until it is supported by its shallow groove. As a result four sides of the panel are fitted into shallow grooves 25 s , taking up its definitive position fitted at its four sides. See FIGS. 2 and 12 .
A practical example of this invention is a panel of approximately 18 mm in thickness comprising an MDF frame (special lightweight medium density fiberboard) having within it approximately 12 mm of expanded polyethylene, and two MDF faces of approximately 3 mm which enclose the material of approximately 12 mm. Each MDF face of approximately 3 mm is clad on its external face with wood veneer and is varnished. The panel has a length of approximately 1215 mm by 605 in width on its face and a thickness of approximately 18 mm. The perimetric groove at its deepest part is approximately 7 mm wide and 19 mm deep, at a distance from the vertex of the face of approximately 4 mm. The lesser groove is approximately 11 mm deep with respect to the same vertex of the face and is at a distance of approximately 4 mm from the vertex of the back. Finally the back is recessed approximately 6 mm with respect to the vertex of the face. See FIGS. 13 , 14 .
The function fulfilled by the cutout recess is to permit the flange of the retaining profile to enter diagonally, this latter being introduced into the deepest level of the groove. The same effect may be achieved by means of a diagonal groove 70 that leaves free the area where the flange of the retaining member must enter the edge of the panel to be able to carry out the installation. See FIGS. 15 a and 15 b.
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The invention relates to a removable ceiling panel, a rectangular material with a face, a back and four sides with edges, installed from beneath and retained horizontally by its four sides, concealing the profiled suspension grid. The panel is supported at the four sides and it is retained by gravity in the vertical direction. The profiled suspension grid is of the standard type known in the market. The design of the sides of the panel permits carrying out its installation on the basis of simple precise movements, which procedure for installation also forms part of the patent applied for. Said installation movements are not natural and, consequently, render the panels aseismic.
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FIELD OF THE INVENTION
The present invention generally relates to a steam generating apparatus and to a method of controlling the pressure of steam in a steam generating apparatus. In particular, the invention relates to a steam generating apparatus having improved heat transfer properties and to a method of controlling the pressure of steam in a steam generating device on the basis of these heat transfer properties.
BACKGROUND OF THE INVENTION
The heating of water, e.g. for generating steam, may be performed in water heating apparatuses or boilers. In these systems, the temperature of the water can be controlled within a certain temperature range by means of a heating device and a temperature sensor as follows: When the temperature signal of the temperature sensor indicates, that the temperature of the water falls below a certain level, the heating device is activated and the water is heated. If the temperature signal indicates, that the water temperature rises above a certain level, the heating device is deactivated.
Heating the water for the generation of steam requires water heating means under pressure and a control of the pressure of the steam. The controlling of the steam pressure can be performed directly by the use of a pressure sensor or indirectly by the use of a temperature sensor. Controlling the pressure by sensing the water temperature makes use of the correlation of the steam pressure and the temperature in the boiler, since during a heating of the water the steam pressure rises, and it decreases, when the water in the boiler is cooling down.
For controlling the pressure in the boiler on the basis of the measured temperature, the temperature of the water needs to be sensed accurately. In particular, the arrangement of the temperature sensor is critical. The sensor may be attached to the side walls of the boiler shell or to the bottom of the boiler shell.
Arranging the temperature sensor at the side walls requires a flat portion for a proper mounting of the sensor, which in turn complicates the forming of the shell. In some of these arrangements a heat conductive paste is applied between the temperature sensor and the boiler shell. This makes additional mounting processes necessary.
Attaching the temperature sensor at the bottom of the boiler shell also is disadvantageously. Some boilers comprise a heating plate with an embedded heating element. The heating plate usually is mounted to the bottom of the boiler shell by means of bolts or screws. A layer of thermal conducting material, e.g. graphite, may be arranged between the boiler and the heating plate to fill the air gap and to improve the heat transfer. However, the heat transfer between the boiler shell and the heating plate is not optimal. Especially during power up the water temperature and the temperature of the heating plate differ considerably. This causes a time delay in the temperature-time curve at the sensing location compared with the temperature-time curve of the water, since the heat transfer from the heating element into the water is considerably delayed. Furthermore, the spatial and temporal temperature distribution in the boiler is not even. For example, water within the sensing area of a sensor attached remotely from the heating device may be heated up later than water within the region of the heating device. This tends to cause either an overshooting of the steam pressure or the opposite.
It is an object of the invention to provide an apparatus and a method of generating steam providing an improved capability of controlling the steam pressure.
SUMMARY OF THE INVENTION
This object is solved by the features of the independent claims. Further developments and preferred embodiments of the invention are outlined in the dependent claims.
In accordance with a first aspect of the invention, there is provided a steam generating apparatus, comprising a body for receiving water to be heated and comprising a first portion comprising a first metal, and a heating device comprising a second portion comprising a second metal, wherein the heating device comprises a heating plate connected with the body by forming an intermetallic layer between the first portion and the second portion, and a temperature sensor for measuring a temperature that is indicative of a pressure inside the body is arranged in thermal contact to the heating device outside the body. The intermetallic layer provides both a mechanical and a thermal connection between the first and second portions of the heating device and the body of the steam generating apparatus. This ensures a rigid mechanical attachment of the heating device to the body and, at the same time, a good heat transfer capability between the two portions on the basis of a single process step. The intermetallic layer may comprise parts of the first metal, the second metal, and/or a third metal, e.g. a soldering metal. Conventional attaching methods like bolting or screwing create an unevenly distributed, mostly spot-like, contact surface. The intermetallic layer provides a large and contiguous contact surface allowing a higher and more uniform heat transfer. The properties of the two metals can be chosen according to the needs of the body and the heating element, respectively. The first metal and the second metal may be each mixture containing two or more metallic elements or metallic and non-metallic elements and may be optimized independently regarding their heat transfer properties. Therefore, the metal of the first portion comprised by the body may be designed to meet the water heating and steam storing requirements, whereas the second metal may be optimized regarding heat generating and transferring requirements. There are several methods of forming the intermetallic layer, which will be discussed below. The temperature sensor may be a thermistor or another sensor producing a signal associated with a sensed temperature. Due to the improved thermal conductivity the temperature sensor may be arranged adjacent to the heating device or may be directly attached to or integrated in the heating device. As a quick heat transfer takes place between the body, the heating device, and the sensing point of the temperature sensor, hence the development of the temperature can be measured by the temperature sensor without much delay.
In this regard, it is advantageous that the first metal is stainless steel. Stainless steel and the like complies with the requirements of low corrosion under a damp heat environment.
Similarly, the second metal is aluminum or an aluminum alloy. These materials combine a good thermal conductivity with good processing properties.
According to a particular embodiment of the present invention, the intermetallic layer is formed by soldering and/or brazing and/or welding. These alternative or combined processing steps create an intermetallic layer between the first portion and the second portion as described above and are well proven methods of joining different metals. Furthermore, metal filled adhesives may also be used to provide a joint showing a high thermal conductivity and a good mechanical connection.
In accordance with an embodiment of the invention, the heating plate comprises a heating element. The heating element may be attached to the heating plate by casting-in, soldering, brazing, welding or similar techniques.
According to a preferred embodiment of the present invention, the heating device comprises control means for controlling the temperature of the water. The generation of steam requires an accurate control of the steam pressure, as discussed above. By utilizing the improved heat transfer capabilities from the body to the heating device and vice versa, an accurate controlling of the water temperature and, in consequence, of the steam pressure may be obtained. Further, the improved heat transfer capability of the intermetallic joint reduces the feedback time in the system and allows for a faster and more accurate control of the water temperature.
In accordance with a second aspect of the invention, there is provided a method of controlling the pressure of steam in a steam generating apparatus comprising a body for receiving water to be heated and comprising a first portion comprising a first metal, a heating device comprising a second portion comprising a second metal, the body being connected with a heating plate of the heating device by forming an intermetallic layer between the first portion and the second portion, and a temperature sensor for measuring a temperature that is indicative of a pressure inside the body, the temperature sensor being arranged in thermal contact to the heating device outside the body, the method comprising the steps of setting the target water temperature for a first time period to a first set temperature, setting the target water temperature for a second time period to a second set temperature higher than the first set temperature, and setting the target water temperature for a third time period to a third set temperature lower than the second set temperature. Adjusting the target temperature of the water to be heated to different temperature levels during several time periods provides a flexible method of controlling the steam pressure of a steam generating device by measuring the water temperature. For example, the steam pressure level may be set to a nominal pressure, corresponding to the first set temperature. During the second time period, a higher temperature setting and therefore also a higher steam pressure level is set. This may be utilized to temporarily raise the steam pressure for providing a steam output at a higher rate without the need to design the components involved for higher pressure. This may be performed at predetermined time periods or in response to a signal or event. Another example is the possibility to compensate for a reduction in the steam pressure that is predictable at a certain time point by respective signals, but not yet detectable via the temperature sensor, as will be discussed later in detail.
According to a preferred embodiment of the invention, the beginning of the second time period and/or the duration of the second time period and/or the second set temperature is at least one of the following: predetermined; a function of the steam output of the steam generating device, and a function of the water input into the steam generating device. Adjusting the target water temperature to a higher level compared to an initial nominal set temperature during a predetermined time period allows for the compensation of regularly appearing steam demands in advance. The beginning of the second time period and its duration may be adjusted in a flexible way to correspond to the expected steam rate output. Further, the configuration of the second time period and a corresponding set temperature may be correlated to the current steam output. For example, the second time period may reflect the current output steam rate and its duration. Accordingly, the same holds for the amount of water input into the steam generating device. Appropriate signals communicating the triggering of the steam output or the water input may be a switch actuated by the user or an electrical signal activating a water pump.
According to a further embodiment of the present invention, the duration of the second time period equals the duration of the steam output or the duration of the water input. In addition, the beginning of the second time period may coincide with the beginning of the steam output and the beginning of the water input, respectively. This is a simple way of improving the controlling of the steam pressure by adding additional heat at appropriate time periods.
Particularly, the second time period is elongated by a time period being a function of at least one of the following: the duration of the steam output, and the duration of the water input. According to the amount of heat power being transferred into the water and according to other aspects of the steam generating device, appropriate heating periods can be chosen to compensate for the heat loss caused by a steam output and a water input, respectively.
It is also preferred, that the step of controlling the water temperature at the second temperature comprises the step of activating the heating device in the case of at least one of the following: the current water temperature is lower than the second temperature; a steam output is requested; and a water input is performed. During the second time period the heating device transfers heat into the water, whenever one of the mentioned events takes place. Even if the current water temperature is still higher than the second temperature, the heating device is activated for preventing or mitigating a future pressure drop.
According to a particular embodiment of the present invention, the step of controlling the water temperature at the second temperature comprises the step of deactivating the heating device, if the current water temperature is higher than a maximum temperature. In order to prevent an excessive increase in steam pressure, the current water temperature is limited to a maximum temperature.
Particularly, the step of controlling the water temperature at the second temperature comprises the step of deactivating the heating device after a time period being a function of at least one of the following: the duration of the steam output; and the duration of the water input.
These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a schematical set up of a steam generating device according to the present invention.
FIG. 2 shows a flow diagram of a temperature cycle.
FIG. 3 shows a first embodiment of a method of controlling the pressure of steam according to the invention.
FIG. 4 shows a second embodiment of a method of controlling the pressure of steam according to the invention.
FIG. 5 shows an alternative second embodiment of a method of controlling the pressure of steam according to the invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 shows a schematical set up of a steam generating device according to the present invention. The steam generating device 10 comprises a water boiler 12 being manufactured by connecting at least two formed metal shells of stainless steal. The boiler 12 has a flat bottom portion 16 and is mounted in a plastic enclosure in a horizontal arrangement. Other orientations like a non horizontal arrangement are also possible. The flat bottom portion 16 of the boiler 12 is attached to a heating device 14 comprising a heating plate 15 and a heating element 22 . The heating plate is made of aluminum—an aluminum alloy or other materials with excellent heat conductivity can also be used. The heating plate 15 comprises a flat upper portion 18 and is attached with its flat upper portion 18 to the flat bottom portion 16 of the body 12 by formation of an intermetallic layer 20 . The intermetallic layer 20 may be formed by welding, brazing, soldering, and the like. The heating element 22 is attached to the heating plate 15 also by forming an intermetallic layer by welding, brazing, soldering, a similar joining method or by casting-in, to ensure a good heat transfer. Further, the heating device 14 comprises a temperature sensor 24 and a water level sensor 30 . The boiler 12 of the steam generating device 10 is further equipped with a safety valve 32 , an electrical steam output valve 34 and a feed water inlet 36 . The feed water inlet 36 of the boiler 12 is connected with an electrical water pump 38 connected with a water tank 40 . Between the water pump 38 and the feed water inlet 36 , a de-airing valve 42 is provided, enabling a connection of the boiler 12 with the water tank 40 being open to the atmosphere. Furthermore, the boiler 12 is connected via an electrical steam output valve 34 and a steam delivery hose 44 with a steam iron 46 . The steam iron comprises a steam trigger 48 . An electronic control unit 26 is connected with the water pump 38 , the heating element 22 , the temperature sensor 24 , the water level sensor 30 , the electrical steam output valve 34 , and with the steam trigger 48 of the steam iron 48 .
The steam generating device 10 is suitable for use in a domestic appliance comprising, besides the steam ironing device shown as a preferred embodiment, a steamer, a steam cleaner, an active ironing board, a facial sauna, a steam cooking device, a coffee making machine and the like. The water level sensor 30 is used to detect changes in the water level of the boiler 12 . When the water level is lower than a certain level or the boiler 12 is empty, the water level sensor 30 sends a signal to the electronic control unit 26 . The electronic control unit 26 activates the pump 38 to feed water into the boiler 12 for raising the water level. When the water level in the boiler 12 is higher than the certain level, the water level sensor 30 sends an appropriate signal to the electronic control unit 26 . The electronic control unit 26 deactivates a pump 38 to stop pumping. In this way, the water level of the boiler 12 is maintained within a certain range. The de-airing valve 42 provides a connection of the boiler 12 with the atmosphere to prevent the boiler 12 from being overfilled with water, if during cooling down after use a vacuum is formed inside the boiler 12 . The water level sensor 30 may be mounted on the heating plate 15 (as shown) or alternatively on the boiler shell, on the side walls of the boiler 12 or even inside the boiler 12 depending on the sensing method used. If the water level sensing is done based on the temperature from the temperature sensor 24 , the temperature sensor 24 can be used as the water level sensor.
The temperature sensor 24 is mounted on the heating plate 15 . In this way, the temperature sensor 24 is located adjacent to an area being in good thermal contact with the water inside the boiler 12 in order to properly sense the water temperature. Since the steam pressure of the water inside the boiler 12 is directly related to the water temperature, the temperature sensor 24 is used to control the pressure of the water. If the sensed temperature is lower than a preset temperature value, the pressure is also lower than the required level. In this case, the electronic control unit 26 activates the heating element 12 . If the temperature sensor 24 signals a water temperature reaching or exceeding the preset temperature value, the heating element 22 is turned off by the electronic control unit 26 . This is a simple way of controlling the steam pressure inside the boiler 12 . More sophisticated methods are described in relation to FIGS. 2 to 5 . It is an advantage of the invention, to change the preset temperature value for the water inside the boiler 12 . Thus, the pressure of the boiler can be set to different levels improving the delivery of steam at different steam rates during normal use. Further, during cool start-up of the boiler with air instead of steam inside the boiler 12 , the pressure tends to be higher. Thus, a lower preset value may be used to ensure the pressure during start-up being under control. After activating the steam trigger 48 , the air will be released together with the steam. Afterwards, higher set temperature values may be used.
A further reduced embodiment of the invention comprises a simple boiler system, for example a boiler 12 without the water tank 40 , the electrical pump 38 , the de-airing valve 42 , and the feed water inlet 36 . As a temperature sensor 24 a thermostatic switch can be used. The power control of the heating device 22 can be performed by the thermostatic switch directly without the need for an additional electronic control unit 26 . Thus, the pressure is controlled at one level, if the thermostatic switch only works at one temperature level.
FIG. 2 shows a flow diagram of a temperature cycle. In step S 10 , the current temperature T curr of water to be heated is compared with the nominal set temperature T nom . If the current temperature T curr is lower than the nominal temperature T nom , the heating element for heating the water is activated (S 11 ). If the current temperature T curr is higher or equal to the nominal temperature T nom , the process continues to monitor the current temperature in step S 10 . After turning on the heating element in step S 11 , in step S 12 again the current water temperature T curr is compared with the nominal temperature T nom . The temperature comparison in step S 11 may be done with a different frequency than in step S 10 . If the current temperature T curr is higher than the nominal temperature T nom , the heating element is deactivated in step S 13 . Otherwise, the monitoring of the current temperature T curr is continued in step S 12 . After turning off the heating element in step S 13 , the process continues in step S 10 and the temperature cycle is finished. This is a simple way of controlling the temperature of water to be heated. The steps S 10 to S 13 may be defined as a temperature regulation cycle using the activating and deactivating of the heating element as a criterion.
FIG. 3 shows a first embodiment of a method of controlling the pressure of steam according to the invention. In step S 20 , the nominal temperature T nom of water to be heated is set to a first temperature T 1 . In step S 21 , a number of N temperature cycles as described in connection with FIG. 2 are performed. In step S 22 , the nominal temperature T nom is set to a second temperature T 2 , the second temperature T 2 being higher than the first temperature T 1 . In step S 23 , M temperature cycles are performed at the higher nominal temperature T 2 . Afterwards, in step S 24 , the nominal temperature T nom is lowered to a third temperature T 3 , the third temperature T 3 being lower than the second temperature T 2 . After performing K temperature cycles, the process continues with step S 20 or, alternatively, with step S 22 . Thus, a higher temperature level T 2 is provided during M temperature cycles allowing the generation of a higher pressure range.
FIG. 4 shows a second embodiment of a method of controlling the pressure of steam according to the invention. In step S 30 , the nominal temperature T nom of water to be heated is set to a first temperature T 1 . Afterwards, in step S 31 , a—preferably not predetermined—number of temperature cycles as defined above is performed. During these temperature cycles, the activation of a steam trigger, i.e. the initiation of a steam output, and the activation of the water pump are monitored (S 32 ). If one of the mentioned events takes place, the process continues in step S 33 . Otherwise, the monitoring continues in step S 32 . In step S 33 , the heating element is turned on and the water is heated. During this heating, several events are monitored. If one of the events takes place, the heating element is turned off. First, in step S 34 , the current temperature of the water, T curr , is compared with a maximum temperature T max . If the current temperature T curr exceeds the maximum temperature T max , the heating element is turned off and the process continues in step S 36 . Second, the steam trigger and/or the water pump are monitored. If one of the two signals shows, that the steam trigger is turned off or the water pump is not operating anymore, the process continues in step S 36 . Otherwise, the monitoring of the events is continued in step S 34 . In step S 36 , the heating element is turned off and the process continues in step S 31 . With this method, the loss of heat due to a steam output and/or a water input is compensated by turning on the heating element instantaneously. The heating element delivers heat into the water, until the heat loss is stopped or a maximum temperature is reached. Thus, the feedback time of the controlling device can be reduced.
FIG. 5 shows an alternative second embodiment of a method of controlling the pressure of steam according to the invention. In this alternative method the steps S 34 and S 35 of FIG. 4 are replaced by the steps S 44 and S 45 . In step S 44 , the current temperature T curr , of water to be heated is compared with a maximum temperature T max . If the current temperature T curr exceeds the maximum temperature T max , the process continues in step S 36 . In step S 45 , the time t leaving the heating element activated is determined as a function of the steam output and/or the water input. Accordingly, during this time t the heating element delivers heat into the water. After this time, the method continues with step S 36 . Also during step S 45 the current water temperature is monitored continuously, in view of the maximum temperature T max . By this method, the compensation of the heat loss may be adjusted according to the heat power being transferred into the water.
Equivalents and modifications not described above may also be employed without departing from the scope of the invention, which is defined in the accompanying claims.
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A steam generating apparatus includes a body for receiving water to be heated and has a first portion including a first metal, and a heating device having a second portion including a second metal. The heating device includes a heating plate connected with the body by forming an intermetallic layer between the first and second portions. A temperature sensor measures temperature indicative of pressure inside the body and thermally contacts the heating device outside the body. A method of controlling the pressure of steam in the steam generating apparatus includes setting the target water temperature for a first time period to a first set temperature; setting the target water temperature for a second time period to a second set temperature higher than the first set temperature; and setting the target water temperature for a third time period to a third set temperature lower than the second set temperature.
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RELATED APPLICATIONS
This application for an invention was disclosed in a prior U.S. Provisional Application Ser. No. 60/579,922 entitled RULES AND DIRECTIVES FOR VALIDATING CORRECT DATA USED IN THE DESIGN OF SEMICONDUCTOR PRODUCTS filed 15 Jun. 2004, that complies with the requirements of the first paragraph of 35 U.S.C. §112. It also relates to U.S. patent application filed on 6 May 2004 Ser. No. 10/840,534 entitled ASSURING CORRECT DATA ENTRY TO GENERATE SHELLS FOR A SEMICONDUCTOR PLATFORM (hereinafter referred to as CORRECT DATA ENTRY) and to U.S. Provisional Application Ser. No. 60/577,356 filed 3 June 2004 entitled LANGUAGE AND TEMPLATE FOR USE IN THE DESIGN OF SEMICONDUCTOR PRODUCTS (hereinafter referred to as the TEMPLATE ENGINE) and U.S. patent application Ser. No. 11/017,017 by the same title, filed concurrently herewith (hereinafter referred to as the TEMPLATE ENGINE), all applications owned by the same assignee as this application and all applications being incorporated by reference in their entireties.
FIELD OF THE INVENTION
This invention relates generally to the field of electronic circuit design and more particularly relates to an arrangement of rules and directives to ensure that data is correct and consistent in the design and manufacture of a semiconductor product.
BACKGROUND
An integrated circuit comprises layers of a semiconductor, usually silicon, with specific areas and specific layers having different concentrations of electron and hole carriers and/or insulators. The electrical conductivity of the layers and of the distinct areas within the layers are determined by the concentration of dopants within the area. In turn, these distinct areas interact with one another to form transistors, diodes, and other electronic devices. These specific transistors and other devices may interact with each other by field interactions or by direct electrical interconnections. Openings or windows are created for electrical connections between the layers by a combination of masking, layering, and etching additional materials on top of the wafers. These electrical interconnections may be within the semiconductor or may lie above the semiconductor areas and layers using a complex mesh of conductive layers, usually metal such as platinum, gold, aluminum, tungsten, or copper, fabricated by deposition on the surface and selective removal, leaving the electrical interconnections. Insulative layers, e.g., silicon dioxide, may separate any of these semiconductor or connectivity layers. Depending upon the interconnection topology, transistors perform Boolean logic functions like AND, OR, NOT, NOR and are referred to as gates.
Meanwhile, several types of chips have been developed that take advantage of a modular approach having areas in which the transistors and their respective functions are fixed and other areas in which the transistors and their functions are totally or partially programmable/customizable. The different proportion of fixed to programmable modules in an integrated circuit is limited by factors such as complexity, cost, time, and design constraints. The field programmable gate array (FPGA) refers to a type of logic chip that can be reprogrammed. Because of the programmable features, FPGAs are flexible and modification is almost trivial but, on the other hand, FPGAs are very expensive and have the largest die size. The relative disadvantage of FPGAs, however, is its high cost per function, low speed, and high power consumption. FPGAs are used primarily for prototyping integrated circuit designs but once the design is set, faster hard-wired chips are produced. Programmable gate arrays (PGAs) are also flexible in the number of possible applications that can be achieved but are not quite as flexible as the FPGAs and are more time-consuming to modify and test. An application specific integrated circuit (ASIC) is another type of chip designed for a particular application. ASICs are efficient in use of power compared to FPGAs and are quite inexpensive to manufacture at high volumes. ASICs, however, are very complex to design and prototype because of their speed and quality. Application Specific Standard Products (ASSPs) are hard-wired chips that meet a specific need but this customization is both time-consuming and costly. An example of an ASSP might be a microprocessor in a heart pacemaker.
A digital system can be represented at different levels of abstraction to manage the description and design of complex systems with millions of logic gates, etc. For instance, a circuit diagram or a schematic of interconnected logic gates is a structural representation; a picture of a chip with pins extending from the black box/rectangle is a physical representation; and the behavioral representation, considered the highest level of abstraction, describes a system in terms of what it does, how it behaves, and specifies the relationship between the input and output signals. A behavioral description could be a Boolean expression or a more abstract description such as the data register transfer level logic (RTL). RTL descriptions are specified by the following three components: (1) the set of registers in the system or subsystem, such as a digital module; (2) the operations that are performed on the data stored in the registers; and (3) the control that supervises the sequence of the operations in the system.
Specialized electronic design automation (EDA) software, referred to as tools, intended to implement a more efficient process to design chips has been introduced. Integrated circuits are now designed with the EDA tools using hardware description languages, typically Verilog or VHDL. VHDL stands for VHSIC (Very High Speed Integrated Circuits) Hardware Description Language, the development of which was sponsored by the U.S. Department of Defense and the IEEE in the mid 1980s. VHDL and Verilog are only two hardware description languages but seem to have become the industry's standard languages to describe and simulate complex digital systems and incorporate timing specifications and gate delays, as well as describe the integrated circuit as a system of interconnected components. Execution of programs in hardware description languages are inherently parallel meaning that as soon as a new input arrives the commands corresponding to logic gates are executed in parallel. In this fashion, a VHDL or Verilog program mimics the behavior of a physical, usually digital, system.
In spite of the implementation of EDA tools, chip designers and testers still manually define the specification and address map for individual registers and internal memory, as well as separately and manually specify the implementation at the RTL, the verification testcases, and the firmware header file. Maintaining consistency and manually editing the multitude of minute modifications often required by this out-dated and tedious approach is very difficult and conducive to many mistakes. There is thus a need in the industry for an automated RULES ENGINE that verifies that a data entry and data changes in any one of the several hundred parameters will be checked for correctness and propagated throughout the entire chip design.
SUMMARY OF THE INVENTION
To meet these and other needs in the industry, the inventors herein present a method, a computer program product, and a RULES ENGINE to validate data for use in the design of a semiconductor, which: reads a plurality of resources of an application set; reads a user's specification intended to be developed from and added to the application set in the design of the semiconductor product; allocates a resource to the design of the semiconductor product; validates the allocation of the resource to the semiconductor product; and propagates the allocation and plurality of parameters of the resource throughout a description of the semiconductor product. To assist with the verification, the names of some of the resources such as phase locked loops, clocks, oscillator sources, reset sources, memories, and I/O ports must be unique, non-null, comply with industry and/or company naming conventions and syntax. The name of some of the resources, moreover, are not duplicated in a user's module, a fixed module, or a generated module of the semiconductor product. The frequency output of an oscillator source, such as a phase locked loop, a primary I/O, or a recovered clock, are all checked to see if the source exists, the output is in an allowable range, and if the feedback and/or dividers and/or reference frequencies are consistent. The allocation of diffused or configured memory is verified for bit width, word length, and whether the resources exist for that width and depth of memory. If the memory is configured from transistor fabric of the semiconductor product, then the amount of transistor fabric allocated to the memory is automatically declared from the available resources. The method, RULES ENGINE, and program product herein also automatically update an index for allocated resources. If the resource is a diffused resource, then the physical reference is updated and made consistent with the allocation. for diffused resources as the diffused resources are allocated. If an I/O buffer is one of the resources allocated, the method, RULES ENGINE, and computer program product ensure that the I/O buffer type, the direction and differentiality of the signals, the reference voltage, if any, and the resource to which the I/O buffer are all compatible and consistent through the specifications of the semiconductor product.
The invention may further be considered a method and a RULES ENGINE to facilitate the design of semiconductor products, the method and engine reading in a plurality of resources available on an application set; reading in a plurality of resources available in and a plurality of requirements for a user's specification; allocating only those plurality of resources to the user's specification that are valid and compatible. If an allocation conflicts with other allocations, specifications, or otherwise renders the semiconductor product nonfunctional, the method and RULES ENGINE disallows the allocation.
The method and Rules Engine always ensures that the specification of the resources of a semiconductor product is always in a valid state.
Other aspects and features of the present invention, as defined solely by the claims, will become apparent to those ordinarily skilled in the art upon review of the following non-limited detailed description of the invention in conjunction with the accompanying figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a simplified block diagram of a networked computer system in which language and template of the builder tool of the invention can be implemented.
FIG. 2 is a simplified block diagram of the functional components within a computer workstation to which an integrated circuit developer may access and use the language and template of the builder tool in accordance with an embodiment of the invention.
FIG. 3 is a simplified block diagram of a semiconductor platform having a number of components, each of which may be considered as generation tasks, having shells that may be generated using the templates and the language of an embodiment of the invention.
FIG. 4 is a simplified diagram illustrating the hierarchy of register transfer level logic of a platform description usable by the template and language of the builder tool in accordance with an embodiment of the invention.
FIG. 5 is a simplified flow chart illustrating how parameters in the language of the invention can be entered correctly and then, using the TEMPLATE ENGINE and the RULES ENGINE, generating correct shells for the design and manufacture of a semiconductor product
FIG. 6 is a simplified flow chart illustrating a process to confirm the correctness of parameters for phase locked loops of a semiconductor product used in accordance with an embodiment of the invention.
FIGS. 7A and 7B are simplified flow charts illustrating a process to confirm the correctness of parameters for clocks and timing of a semiconductor product used in accordance with an embodiment of the invention.
FIG. 8 is a simplified flow charts illustrating a process to confirm the correctness of parameters for memories of a semiconductor product used in accordance with an embodiment of the invention.
FIGS. 9A and 9B are simplified flow charts illustrating a process to confirm the correctness of parameters for input/output buffers and signals of a semiconductor product used in accordance with an embodiment of the invention.
FIG. 10 is a screen shot of one example of how a user may select certain data and certain shells to generate in accordance with an embodiment of the invention.
FIG. 11 is a graphical user interface embodying a description of the resources available on a slice to be designed into a semiconductor product using the templates and the language as described herein.
FIG. 12 is a screen shot of a graphical user interface illustrating a completed I/O specifications table having correct parameters that have been checked against an embodiment of the rules and directives of the invention.
DESCRIPTION OF THE INVENTION
The present invention now will be more fully described with reference to the accompanying drawings, in which illustrative embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough, complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers may refer to like elements and process steps throughout.
Referring to FIG. 1 , which illustrates an exemplary computer system 100 upon which a tool to validate the correctness and use of data during the design of a semiconductor product as disclosed herein, could be installed and/or used. Computer system 120 is illustrated as a networked computer system that includes one or more client computers 122 , 124 and 130 such as workstations coupled through a network 128 to a server 126 . Server 126 could also be a personal computer, a workstation, a midrange computer, or a mainframe computer. While shown here as a point-to-point connection, computers 122 and 124 need not be coupled to server 126 directly, but may be coupled to yet another network which in turn is connected to server 126 . Network 128 represents any type of networked interconnection including but not limited to local-area, wide-area, wireless, and public networks such as the Internet or an Intranet, and any number of routers and hubs connected in between, e.g., a local-area network to a wide-area network to the Internet through a series of routers and/or other servers. Any number of computers and other devices may be networked through network 128 , e.g., multiple servers, hand-held devices, etc.
For the purposes of the invention, computer 130 may represent practically any type of computer, computer system, or other programmable electronic device, including a client computer similar to computers 122 , 124 of FIG. 1 , a server computer, e.g., similar to server 126 of FIG. 1 , a portable computer, an embedded controller, a hand-held device, etc. Computer 130 may be coupled in a network 128 as shown in FIG. 1 or may be a stand-alone device. Computer 130 will hereinafter also be referred to as a computer although it should be appreciated that the term “computer” may also include other suitable programmable electronic devices capable of allowing a chip designer to use the RULES ENGINE.
With reference to FIG. 2 wherein the method and apparatus of correctly generating shells and of validating the correctness of the data throughout the design process for a semiconductor product as disclosed herein is installed as an application on computer 230 . Computer 230 typically receives a number of inputs and outputs for communicating information externally. For interface with a user or operator, computer 230 typically includes one or more user input devices 236 , 237 , e.g., a keyboard 136 and/or mouse 140 of FIG. 1 , a trackball, a joystick, a touchpad, and/or a microphone, among others, and one or more output devices 232 such as a display 142 and/or a printer 144 of FIG. 1 , a speaker, among others. Some servers, however, do not support direct user input and output. For additional storage, computer 230 may also include one or more storage devices 148 of FIG. 1 , e.g., a floppy or other removable disk drive, a hard disk drive, a direct access storage device, an optical drive, e.g., a CD drive, a DVD drive, etc., and/or a tape drive, among others, that may be connected directly or other storage 246 that may be connected through a storage area network (SAN) or other network 228 . Furthermore, computer 230 may include an interface connected to one or more networks 228 , e.g., a local-area network, a wide-area network, a wireless network, and/or the Internet, among others, to permit communication of information with other computers 122 , 124 coupled to the network 128 . It should be appreciated that computer 230 typically includes suitable analog or digital interfaces between processor 240 and each of the components as is known in the art.
Computer 230 typically includes at least one processor 240 coupled to a memory 242 . Processor 240 may represent one or more processors or microprocessors and memory 242 may represent the random access memory (RAM) devices comprising the main storage of computer 230 , as well as any supplemental levels of memory such as cache memories, nonvolatile or backup memories, programmable or flash memories, read-only memories, etc. In addition, memory 242 may be considered to include memory storage physically located elsewhere in computer 230 , e.g., any storage capacity used as a virtual memory, e.g., as stored on a mass storage device 246 coupled to computer 230 with a SAN or on another computer coupled to computer 230 via network 228 .
Computer 230 may operate under the control of an operating system 250 such as a UNIX-based, LINUX-based, or WINDOWS-based operating system, as is known in the art, but is not so limited by the particular operating system, or indeed need not be under the control of any operating system. Operating system 250 typically executes various computer software applications, components, programs, objects, modules, etc., such as an executable program 252 , etc. Although the tools and libraries 260 for developing an integrated circuit may be in memory 242 , they need not be. The processor 240 may access the tools and libraries 260 , the required data, other various applications components, programs, objects, modules, etc., resident on one or more processors in another computer coupled to computer 230 via a network 228 , e.g., in a distributed or client-server computing environment whereby the processing to implement the functions of the correct shell generation tool may be allocated to multiple computers over a network.
In general, the program or method steps which cause a computer to validate correct data during the design of a semiconductor product, whether implemented as part of an operating system or a specific application, component, program, object, module, or sequence of instructions, will be referred to herein as the RULES ENGINE. The RULES ENGINE typically comprises one or more instructions that are resident at various times in various memory and storage devices in a computer, and that, when read and executed by one or more processors in a computer network, cause that computer to perform the steps necessary to execute steps or elements embodying the various aspects of the invention. While the invention has and hereinafter will be described in the context of fully functioning computers and computer systems, those skilled in the art will appreciate that the various embodiments of the invention are capable of being distributed as a program product in a variety of forms and that the invention applies equally regardless of the particular type of signal bearing media used to actually carry out the distribution. Computer program code for carrying out operations of the present invention may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer. In the latter scenario, the remote computer may be connected to the user's computer through a network 128 , for example, the Internet using an Internet Service Provider. Examples of signal bearing media include but are not limited to recordable type media such as volatile and nonvolatile memory devices, floppy and other removable disks, hard disk drives, optical disks, e.g., CD-ROMs, DVDs, etc., among others, and transmission type media such as digital and analog communication links.
One input to the RULES ENGINE is the application set. An application set is, inter alia, a description of the platform and several shells that make the platform useful to a chip designer. Viewing FIG. 3 , a platform 310 is a partially manufactured semiconductor device in which the wafer layers up to the connectivity layers have been fabricated. The platform 310 comprises a base semiconductor wafer from, e.g., silicon, silicon-on-insulator, silicon germanium, gallium arsenide, other Type II, IIII, IV, and V semiconductors, etc. and is a piece of semiconductor material into which blocks or hardmacs have been diffused into the semiconductor layers. Diffusing a semiconductor wafer to create a hardmac simply means that during fabrication of the wafer layers, transistors or other electronic devices have been particularly arranged in the wafer layers to achieve specific functions, such as diffused memory 320 - 328 , 330 - 338 , data transceiver hardware such as I/O PHYs 340 - 346 , clock factories including phase-locked loops (PLLs) 450 , control I/Os 352 , configurable input/output (I/O) hardmacs 354 , 356 ; each of the hardmacs have an optimum arrangement and density of transistors to realize its particular function. The platform further comprises an area of transistor fabric 360 for further development of the platform 310 using a suite of generation tools, each of which may incorporate the RULES ENGINE as described herein. Transistor fabric 360 is an array of prediffused transistors in a regular pattern that can be logically configured by the suite of generation tools herein to achieve different functions. A cell refers to the personalization of the interconnect layers that instantiate the logic gates of the transistor fabric. A memory compiler (not shown) may have compiled some blocks of diffused memory 320 - 338 for specific sizes, timing requirements, connections, etc. The placement of these hardmacs, compiled memories, and the reserved areas of the transistor fabric 360 have been situated to achieve the desired timing and performance both within the platform and for the platform 310 to connect externally.
One of skill in the art will appreciate that the platform 310 shown in FIG. 3 is only one example of a platform and its components. Different platforms may contain different amounts and arrangements of transistor fabric, different amounts of diffused and/or compiled memories, both fixed and configurable I/O blocks, clocks, etc. depending upon the purpose of the final integrated chip. For instance, if the final chip is intended to be a communication and/or network integrated circuit, the periphery of the platform may contain many I/O hardmacs that have been fixed as PHYs and/or that can be configured differently from one another. Likewise, if the final integrated chip is intended to be a specialized microprocessor then it may not have as many I/O hardmacs or configurable I/O, and more or less diffused registers and memories. The point is that there are different platforms for different semiconductor products. The platform 410 , moreover, optionally may include the contact mask and some of the fixed higher layers of connectivity for distribution of power, ground, and external signal I/O.
The platform definition is a detailed listing of the physical resources features available on the platform, such as the area and availability of transistor fabric, the I/O and memory available, the requirements of the hardmacs, the cost of the platform, the ideal performance that can be expected of the platform, the expected power consumption, and other functional requirements. For memory elements, the platform definition may include, inter alia, details of: (a) area and physical placement of the memory array and its interface/connection pins; (b) bit width and depth; (c) organization, e.g., numbers of read/write ports, bit masking; (d) cycle time; and (e) power estimates. For I/O elements, the platform definition may provide, inter alia, the types of I/O, the I/O drive strength, etc. For clock elements, the platform definition provides the frequencies at which the platform may operate, the duty cycle, etc. Other details of the platform definition may include the configuration of the transistor fabric and the diffused and compiled elements, the status of the logic, the required control signals and the features enabled by the control signals, whether any element undergoes testing, the location and the number of the elements on the platform, etc.
The platform and its definition are of little use to a designer needing to develop a functional integrated circuit, so several representations of the diffused resources of the platform are needed; shells are these representations. Shells are the logic and other infrastructure that makes the platform useful as a design entity, and the RULES ENGINE described herein is preferably used to generate these shells. The platform description is input to circumscribe all other generated parameters and other user input to make the platform useful to design a semiconductor product. Using the RULES ENGINE and a suite of other generation tools, a chip designer can integrate her/his customer's requirements with the platform's resources and definition to verify and synthesize designs generated by each tool, insert clocks, create the test interconnects, and then integrate the designs together to create a complete design. The resultant design, moreover, is a qualified netlist with appropriate placement and routing amongst the existing resources and for external connections to a board. To create a customized chip, all that is needed is a small set of remaining masks to create the interconnections between the preplaced elements.
There are a number of shells used by a designer to integrate her/his customer's requirements using a particular platform description, and depending upon the designer's particular task; one or more of these shells can be used. While the following description is not intended to be limitative, it is nonetheless, fairly representative of the infrastructure necessary to use the platform and create a functional semiconductor product from the platform. These shells comprise: the RTL shells, the documentation shell, the verification shell, the synthesis shell, the static timing analysis shell, the manufacturing test shell, the floorplan shell, and the RTL qualification shell. The RTL shell provides a logical description of the platform, and the generated or user resources. The documentation shell may be considered the functional description of the resources. The verification shell is the functional verification description, and the synthesis shell may be thought of as the generation description. The static timing analysis shell is the timing description, the manufacturing test shell is the test description, and the floorplan shell is a location description of the platform resources.
An additional perspective of these shells may be obtained by abstracting the semiconductor product as modules based upon the source of the RTL and the function of the logic, such as shown in FIG. 4 . One of skill in the art will understand that these shells are not necessarily generated according to this or any other abstraction; that is to say, a generated verification shell or any other shell may have aspects in one or more of these modules and that the shells are not necessarily generated in the order of or limited to the following modules. The information is presented to show the complexity and the interconnectedness of the shells with each other and with the modules throughout the semiconductor platform. The generated module 410 preferably comprises the shells generated by a suite of generation tools for I/O, memory, clocks, or may be derived from other known semiconductor design tools such as described in copending United States patent applications, commonly owned by the assignee herein and hereby incorporated by reference in their entireties: Ser. No. 10/435,168 filed 8 May 2003 entitled AUTOMATION OF THE DEVELOPMENT, TESTING, AND RELEASE OF A FLOW FRAMEWORK AND METHODOLOGY TO DESIGN INTEGRATED CIRCUITS; Ser. No. 10/318,792 filed 13 Dec. 2002 entitled FLEXIBLE TEMPLATE HAVING EMBEDDED GATE ARRAY AND COMPOSABLE MEMORY FOR INTEGRATED CIRCUITS; Ser. No. 10/318,623 filed 13 Dec. 2002 entitled AUTOMATED SELECTION AND PLACEMENT OF MEMORY DURING DESIGN OF AN INTEGRATED CIRCUIT, Ser. No. 10/334,568 filed 31 Dec. 2002 entitled PLACEMENT OF CONFIGURABLE INPUT/OUTPUT BUFFER STRUCTURES DURING DESIGN OF INTEGRATED CIRCUITS; Ser. No. 10/335,360 filed 31 Dec. 2002 entitled A SIMPLIFIED PROCESS TO DESIGN INTEGRATED CIRCUITS; Ser. No. 10/465,186 filed 19 Jun. 2003 entitled DESIGNING AND TESTING THE INTERCONNECTION OF ADDRESSABLE DEVICES OF INTEGRATED CIRCUITS; and Ser. No. 10/713,492 filed 14 Nov. 2003 entitled FLEXIBLE DESIGN FOR MEMORY USE IN INTEGRATED CIRCUITS. The generated module 410 may include some preplaced, timed, and proven components, such as one or more clock generators, system controllers and reset logic, test controllers, and/or analog serializers/deserializers (SERDES) hardmac components. The generated module 410 has connectivity requirements to the various modules and their components through bus logic 418 to the several modules along an internal bus 480 and/or external bus 482 . Bus logic 418 may include arbiters, multiplexers, decoders, etc. to manage the connectivity and, if necessary, the address translation and register/memory coherence schemes.
Surrounding the generated module 410 is the user module 420 . Logic from the customer for whom the integrated circuit is designed comprises the user module 420 and may include prefabricated logic and hardware such as cores, hardmacs, IOs, registers 422 , etc. Also included in the user module 420 may be a list of memories and/or registers having tie-offs, i.e., the memories and/or registers that will not be used for data flow and may thus be allocatable for performance enhancing features such as control status registers, etc. The user module 420 also provides input into the RULES ENGINE described herein.
The fixed module 430 is created with the application set and thus encompasses the fixed resources and the shells pertaining to these fixed resources of the application set. The fixed module 430 and its accompanying shells provide the template upon which the customer's requirements will be built and are input into the RULES ENGINE described herein. The fixed module 430 may be as simple as logic signals directly connected to external chip I/Os, or it may be more complex logic upon which the user module 420 and the generated module 410 can build. For example, shells of the fixed module 430 could include the complete infrastructure to support a PCI bus controller 432 , 432 a including all the connections to external I/Os and/or a DDR/SRAM memory controller, a processor subsystem 436 , 436 a , etc. The RULES ENGINE herein accepts the shells of the fixed module 430 and then further facilitates matching and binding the memories, register blocks, any cores 436 in the fixed module to the top module 450 , such as matching protocols and correctly binding the correct I/O hardmacs PHYs 452 , such as an XGXS to support data transfer at Gigabit Ethernet speeds, or a MW SPI-4 core.
The core module 440 encompasses the fixed module 430 and the user module 420 and may be described as the correct and proven logic interfaces connecting them with each other and with the top module 450 . The top module 450 contains the logic and supporting shells for the hardmacs and configured logic towards the periphery of the platform for outside communication. The top module 450 thus contains the I/O blocks and I/O diffused areas and any registers associated with the hardmac and configurable I/Os. The instantiated I/O blocks that use the top module 450 may include the PLLs, the I/O netlists of which a NAND tree is a part, test logic, and lock detect circuits, etc. A number of input tables describing the interconnect templates are used by the RULES ENGINE to integrate the bus masters of 452 a 454 a , 456 a , 458 a , 462 a of their respective top module components 552 , 554 , 556 , 558 , 562 with the application set and the rest of the design. These top module components may include a JTAG TAP controller 456 , an Ethernet interface 452 , a CPU connection interface 454 , and/or an EEPROM interface 458 , etc., each of which may require special consideration when inputting associated parameters.
FIG. 5 is a simplified flow chart of a method 500 of generating correct shells for the platform and modules described in FIGS. 3 and 4 . In FIG. 5 , the process 500 begins at step 510 whereby the application set and user requirements of the user module and its shells are automatically input to the TEMPLATE ENGINE. At step 512 , the RULES ENGINE and TEMPLATE ENGINE read the parameters of the application set and/or the user's specification, for example, the names of signals, names of inputs/outputs, etc., that will be used to generate a shell(s). At this time the input parameters of the shells are checked to ensure their correctness and completeness at step 514 , preferably by the CORRECT DATA ENTRY and the RULES ENGINE. If the input parameters are not correct, then the process immediately loops back to step 512 giving the user an opportunity to enter correct shell parameters. If, however, the parameters for the shell are correct, the user selects a shell, such as an RTL, simulation, documentation shell, to generate at step 516 . Then, at step 518 , the shell(s) is/are automatically generated e.g. by allocating the appropriate data to its respective template, such as described the TEMPLATE ENGINE. After the shell is generated, then different paths of FIG. 5 are taken depending upon the particular shell. For instance, if the correctly generated shell is an RTL and/or simulation shell, then at step 522 , the RTL is compiled. Note, that at this time, the RTL language and syntax will be correct and need not be checked. Then, the RTL is then simulated as in step 524 to determine how the actual signals will transfer from register to register, and the process returns at step 585 . After generation of the correct documentation shell 530 , the process returns. The correct timing shell 540 will undergo timing analysis at 542 and return. The correct manufacturing test shell 550 generated by the tool as described herein can be used to generate manufacturing vectors at step 552 which will be tested at step 554 . The correct synthesis shell 560 will be run at step 562 , and the correct floorplan shell 570 will generate a floorplan as in step 572 . The RULES ENGINE as described herein ensures that the parameters input into it and other generation tools are correct, complete and comply with any rules and constraints put upon them.
FIG. 6 is one of the flowcharts of the RULES ENGINE that assures correct input and distribution of correct data into the specifications used to generate the shells for each component. FIG. 6 addresses the rules and directives for phase lock loops; FIGS. 7A and 7B present a flow of the process whereby parameters and specifications of clocks are confirmed for correctness by the RULES ENGINE. FIG. 8 is a flowchart of the rules and directives for the memories of a semiconductor product. FIGS. 9A through 9B deal with the complexity of checking the input/output buffers and signals for correctness by the RULES ENGINE during the generation of shells. One of skill in the art will of course realize that the concept and the rules and directives herein are not limited to PLLs, clocks, memories, and I/O buffers, but can apply to complex hardmacs that have register spaces, such as processors. The figures are understandable knowing the nomenclature and conventions. An arrow connecting a block to itself or other blocks means that the values or names in the block are consulted to obtain new values or names and/or are changed as a result of a change in the first block. The numbers around a box indicate the order of evaluation. And notion of xCy means that x is conditional on y being true whereas the notation xCyF means that x is conditional on y being false.
There are preferences for the syntax for signal names, as outlined in the TEMPLATE ENGINE, filed concurrently here within, but which will be reiterated here for convenience. Signal names preferably contain A-Z, a-z, 0-9, _, and [ ], and start with A-Z or a-z. Multiple underscores ______ tend to be burdensome and uninterpretable given the language and syntax and are therefore discouraged. Numbers are allowed only between brackets, such as [12345678]. For floating point numbers, it is preferred that they do not contain exponential notation and be less than one million. Integers are preferably numeric characters with a maximum number of nine characters.
Following is a list of some of the parameters, data that could be included in the original data from the application set and/or the user's specification and/or generated during the process of chip design.
Bump 904
The location of the 1/0 on the silicon die.
Package Ball 906
The physical location on the package where a signal will be located.
Side 1202
The side of the die where the signal is located. Possible values are: LEFT, RIGHT,
TOP or BOTTOM.
Diff Pair 1204
The matching bump to make up a differential pair.
Power Plane 1206
This field indicates how the bump is used. Possible values are: Power, Signal,
Ground, SignalPower, or SignalGround.
Segment
Segment Region of the power plane that the signal passes through.
Signal Name (Platform)
Name of the signal associated with the package location. The name chosen must
1020
comply with all signal name naming conventions. Refer to Naming Conventions.
Signal Name (User)
Name of the signal associated with the package location. You must choose a name
1024
that complies with all signal naming conventions. Refer to Naming Conventions.
Diffused I/O Type
This field indicates the type of I/O buffer that is diffused onto the slice. Diffused I/O
940
buffers can be configured or fixed.
I/O Direction 1050
This field indicates the maximum capability of the I/O buffer. Possible values for this
field are: IN, OUT, INOUT, or blank.
VREF or Bzgrp 910
If the buffer type require a VREF, this field identifies the signal name used as a
(Platform)
voltage reference for the I/O buffer. If the buffer type is BZ I/O, this field indicates
the EN Update Block that controls this buffer.
VREF or BZgrp (User)
If the buffer type requires a VREF, this field identifies the signal name used as a
920
voltage reference for the I/O buffer. If the buffer type is BZ I/O, this field indicates
the EN Update Block that controls this buffer.
I/O Use (Platform) 1054
This field indicates the direction of the I/O. It will automatically be filled in if the I/O
Direction is IN, OUT, or blank. If the I/O direction is INOUT, possible values are IN,
OUT, INOUT, or blank.
I/O Use (User) 1058
This field indicates the direction of the I/O. It will automatically be filled in if the I/O
Direction is IN, OUT, or blank. If the I/O direction is INOUT, possible values are: IN,
OUT, INOUT, or blank.
Configurable I/O Type
This field indicates what type of configurable I/O buffer is being used.
(Platform) 950
Configurable I/O Type
This field indicates what type of configurable I/O buffer is being used.
(User) 1040
Component Type 960
Type of component to which the signal is being routed. The possible values are:
(Platform)
None, PLL, GigaBlaze core, HyperPhy core, DDR, and UCM.
Component Name 970
The name of the component to which that signal will connect. A drop-down list is
(Platform)
generated for each component type.
Component Port 1060
Name of the port on the component to which that signal connects. A drop-down list
(Platform)
is generated that is dependent on the component type and name.
Component Type (User)
Type of component to which the signal is being routed. The possible values for
990
component types are based on what Component Type (Plafform) was chosen.
Component Name (User)
The name of the component to which the signal will connect.
1010
Component Port (User)
Name of the port on the component to which the signal connects.
1070
Test Usage (Platform)
This field states if the signal is to be used for test purposes. Possible values are: No
1066
Test, Dedicated, Shared and Reserved.
Description 1210
Used to enter additional description about the primary I/O.
Note 1212
Use this field to add any additional information about the primary I/O.
Setup Time (ns)
A requirement specifying the minimum time in nanoseconds that the data must be
stable on the pin prior to the capturing clock edge.
Capture Clock
The name of the clock used to capture data on input ports. A drop-down list is
generated from the list of all clocks defined in the Clock Specifications Table.
Output Time (ns)
A requirement specifying maximum time in nanoseconds between the sourcing clock
edge and the point at which the data will be stable.
Sourcing Clock
The name of the clock used to launch data on output ports. A drop-down list is
generated from the list of all clocks defined in the Clock Specifications Table.
Cap Load (pF)
The amount of capacitive load on the I/O buffer.
Clock Name 720
The name of the clock component. This must be a unique name. Refer to the Naming
Conventions section.
Clock Mode 740
The mode of clock output for a clock factory element. This defines how many
outputs the clock factory element needs. Possible values are: Nominal, Nominal
Early, Nominal Late, or Nominal Early Late.
Frequency 780
This field is computed. The value of this field is the result of the value in the
Oscillator Source Frequency field divided by the value in the Divider field.
Osc Source Frequency
The divider for the Oscillator Source Frequency.
Divider 730
Alternate Clock Creates a clock with a multiple selection source
Osc Source Type 770
The oscillator source for the clock component. Possible values are: Primary I/O,
PLL, or Recovered Clock.
Osc Source Name 750
The logical name of the oscillator source. If the Oscillator Source Type is Primary
I/O, then this field is the name of a primary I/O. If the Oscillator Source Type is
Recovered Clock, then this field is the name of a UCM port. If the Oscillator Source
Type is PLL, then this field is the name of a PLL.
Osc Source Frequency
The frequency of the oscillator source.
760
Reset Source Name
The name of the reset source for the clock component. If the name does not match
790
any primary I/O name, then a UCM port is created with the Reset Source Name.
PLL Name 602
The logical name for the PLL component. Each PLL
component must have a unique name.
PLL Type 630
The type of PLL component.
Physical Reference 632
Reference location to a unique PLL on the slice.
Output Frequency 614
The output frequency of the PLL. This value is determined from the Feedback
Divider and Reference Frequency.
Feedback Divider 624
The divider for the Reference Frequency.
Reference Frequency
Used to derive the output frequency. This is required to achieve the Output
626
Frequency.
Memory Name 820
The logical name for the memory component. Each memory component must have a
unique name. Refer to Naming Conventions.
R-Cell Only 840
A value that indicates if the logical memory component should be created from
R-Cell only or if the tool should choose between R-Cell and diffused elements. A
value of True, forces the tool to create a memory logical component from R-Cells. A
value of False, allows the tool to choose between diffused and R-Cells when
creating a logical memory component. This field can only contain a true or false
value.
Memory Ports 874
The number of ports for the logical memory component. Possible values are: 1
read-write, 2 read_write, and 1 read and 1 write.
Number of Words 830
The number of words for the logical memory component. The number of words
defines the depth of the memory.
Number of Bits 850
The number of bits for the logical memory component. The number of bits defines
the width of the memory.
Frequency (MHz) 880
The desired frequency of memory.
Pipeline Stages. 890
Defines how flip-flops will be placed in memory access paths to assist in timing.
Possible values are: Flop In, Flop Out, Both, or None
Error Protection 876
This field indicates if error protection logic should be built and the memory size
adjusted accordingly for the logical memory component. Possible values for this field
are ECC, Parity, or None.
Physical Reference(s)
Specifies the exact Diffused Memory Element(s) to use when constructing a logical
860
memory. This field does not apply if the memory component is built using R-Cells.
For diffused memories, if the user does not select a physical reference, the tool
selects one.
As a result of using the TEMPLATE ENGINE and CORRECT DATA ENTRY with the RULES ENGINE herein, component types picked by a user or customer match the component type of application set or the user module or not at all. The terms in parenthesis, Platform and User, such as on the charts as in FIG. 9A VREF (Platform) or in FIG. 9B Component Port (User), indicate whether the component is part of the application set as defined herein earlier, i.e., a partially manufactured semiconductor device that can be further developed by the user into a customized semiconductor product, or whether the component is added by the user in finalizing her/his integrated circuit design. Of course, an intermediate purpose of the TEMPLATE ENGINE and the RULES ENGINE is to generate the shells that are necessary and facilitate the design and manufacture of semiconductor products. Examples of some of the rules of the RULES ENGINE are that at the time of generating the shells, the method herein checks that the port per instance must be unique for single ended buffer types. The port can be duplicated only for differential buffer types. Uniqueness of the I/O names is checked, as well as assuring that the ports for the core module and the user core module are unique and are defined. Single bit buses, moreover, are either not allowed or discouraged. The rules pertaining to each resource will be further explored.
FIG. 6 applies the rules and directives applicable to the parameters of the specifications table of phase lock loops (PLL). At step 602 , a PLL, of which there may be more than one on the application set, or in the customer's requirements is given a name. The RULES ENGINE herein applies four checks to the block labeled PLL Name 602 : first, the name must be unique and non-null as indicated along path 604 . If the name is unique and non-null, then the name is checked to determine if it is unique at the core module, the user module, the fixed module, and the generated module (see FIG. 4 and discussion herein) along path 606 . Below is a basic checklist of some of the ports in the modules to consider: the core module components, ports of the generated modules, the input signals and output signals of the generated modules, such as the test signals, the reset source name, the oscillator source name, companion enable, i.e. the Alternate Clock and select signal for the companion enable, and the Reset Pulse Source whose signal could end with _RST_PULSE_SRC_N. The output signals of the generated module could include the test signals, the clock name, and the reset name. The fixed module has its ports, input signal names and output signals names; as does the user core module. One of skill in the art will further recognize that there may be proprietary name rules, checks and requirements to be included in these figures and conventions. If the name is unique within these modules, i.e., condition 2 is true, then, at 3 along path 608 , the oscillator source name ( 750 in FIG. 7A ) must be updated, if the PLL is used as the source of oscillation. At 4 , paths 610 and 612 , the component names of the platform and user ( 970 and 1010 in FIG. 9A ), respectively, must be updated.
Block 632 of FIG. 6 refers to a physical reference indicating that the PLL is a diffused resource; the RULES ENGINE will check that the name of the physical reference is non-null, unique, and complies with signal base syntax, either conventional and/or proprietary, see e.g, columns 632 of FIGS. 10 and 1330 of FIG. 11 . Block 630 refers to the type of PLL, and example of which is given in column 1328 of FIG. 11 . Of course, they may be different types of PLL, each given a unique index as in block 660 and perhaps each having their own rules, consistency checks, etc. The range and naming conventions of the output frequency 614 is checked along path 616 so the value chosen for the output frequency is within an allowable range. Then at path 618 , the feedback divider 624 may be changed along path 628 to maintain the reference frequency 626 . If, however, given an output frequency or a change in the output frequency 614 , the feedback divider and the output frequency cannot be maintained, as in path 620 , then the reference frequency 626 needs to be changed. If the output frequency 614 has changed, oscillating source frequency ( 760 in FIG. 7A ) is updated along path 622 .
Referring now to the FIGS. 7A and 7B , which applies rules and directives for the correct clock naming and actions. An index 710 is maintained; there usually is more than one clock name or clock, sometimes up to sixty or more for a communications semiconductor product, in the design so the index helps to keep track. At block 720 , a clock name is checked at loop 604 , to validate that the name is unique, non-null, and compiles with the conventions and/or requirements for signal names. In loop 606 , the name is checked to determine it is unique at the core module level indicating that name is not duplicated in the user module, the fixed module, and the generated module. Then, at path 722 , if the name of the clock is changed, then the change may also propagate and affect the alternate clock 732 which must also have a unique, non-null, name compliant with naming syntax conventions and proprietary requirements. If, however, a user performs a row delete operation on the clock specifications table, as in FIG. 7B path 734 , then the RULES ENGINE determines if the alternate clock 732 should also be deleted or is otherwise affected.
At block 730 a change in the divider's value updates the frequency 780 along path 628 . Also affecting frequency 780 is a change in the oscillator source frequency 760 to maintain an appropriate range. The oscillation source frequency 760 must comply with floating point syntax, as along path 604 . Note that along path 622 , a change in the output frequency of the connected PLL ( 614 in FIG. 6 ) also affects the oscillation source frequency 760 .
Block 750 refers to the oscillation source name, which preferably is non-null and complies with signal base syntax. If the oscillator source 750 is a PLL (as in 602 of FIG. 6 ), or a primary input/output (I/O) signal, or a recovered clock, the RULES ENGINE herein verifies the name also exists in the table for PLLs and I/Os. The name of the oscillator source 750 must be unique throughout the models, as along path 606 . Also affecting the oscillator source name 750 is the oscillator source type 770 in FIG. 7B ; a change in the oscillator source type 770 ripples along path 752 to the oscillator source name 750 . Path 752 of the RULES ENGINE chooses a name for the oscillator source name 750 depending upon whether the source is a PLL, a primary I/O, or a recovered clock. Likewise, a user's change of the signal name ( 1024 in FIG. 9B ) can affect the oscillator source name 750 , as in path 758 , depending upon the present value of the signal name. If the name exists as the oscillator source name 750 and if the oscillator source type 770 is a primary I/O signal, then the oscillator source name 750 is set to a new value and the RULES ENGINE applies this change to a clock specification table similar to the I/O specification table of FIGS. 10 and 12 .
Referring to FIG. 7B , the oscillator source type 770 is given a name which along path 772 must be unique, non-null. If, moreover, a PLL has not been defined in the PLL specification, the oscillator source type 770 cannot be a PLL; similarly, if no primary I/Os have been defined in the I/O specifications, then the oscillator source type 770 cannot be a primary I/O. The changes of the oscillator source type 770 also affect the oscillator source frequency 760 along path 762 , and affect the oscillator source name 750 , as discussed.
The reset signal is named as in block 790 of FIG. 7B and its name must be non-null and comply with the signal name base syntax and industry and/or company conventions. The reset source name 790 is connected to the signal name defined by the user ( 1024 in FIG. 9B ) such that if the user changes or creates a name for the reset signal coming from the reset source 790 , the RULES ENGINE also changes the reset source name 790 . These rules and directives are only examples of what might be implemented when designing and instantiating a clock for a semiconductor product. A table may be constructed with all the parameters; if a rule or directive limits the choices for a particular clock, those limited parameters will be offered, or grayed out, or otherwise made to be not available during the correct entry of the parameters.
FIG. 8 is an example of how the rules and directives and influences in specifying memory in a semiconductor product can be applied. An index 810 of the memory usage is created and a memory is given a name in 820 which must be unique, non-null, and comply with any syntactic requirements and conventions. The number of words in a memory are input in block 830 and the bit width of each word is input at block 850 and the RULES ENGINE herein automatically verify the numbers of words and bit width are valid, i.e., the depth and width of the words are allowable and the input value complies with the syntax requirements, such as integer base. Along paths 832 and 852 , once the depth and width are validated, the physical reference 860 to the diffused memory of platform resources are updated. The physical reference 860 will be checked at 604 to see if it satisfies the requirements of other fields, such as words 830 , bits 850 , ports 874 , and if so, the physical reference 860 is allowed.
Along path 842 , if memory is configured from the transistor fabric, labelled R-cell 840 , the Rules Engine will consult and update the resource viewer of FIG. 11 by checking if there are any Rcells available as in block 1348 and then updating block 1346 to indicate that the some of the transistor fabric has been allocated, as in block 1346 .
FIGS. 9A and 9B present the rules and directives for the I/O specifications to incorporate the platform resources with the user's requirements to achieve a semiconductor product. The parameters can be conveniently categorized into user requests and platform resources. Such requests and resources presented in FIG. 9 are not intended to be limitative but rather, are examples of platform resources and user's requests. Reference voltage of the platform 910 and the reference voltage specified by the user 920 are two such resources and requests. The RULES ENGINE checks the reference voltages of both or either the platform 910 and the user 920 to determine if the name complies with syntactic requirements, as along path 604 . In this instance, an empty string for the value of the voltage is acceptable. In a preferred embodiment, the reference voltage is always derived from an external I/O source, so the RULES ENGINE confirms that the I/O buffer type is correct for a reference voltage. The RULES ENGINE further verifies that the names and values also exist in the Signal Name blocks of the platform 1020 along path 932 and that the new value exists in the Signal Name block of the user 1024 along path 922 , respectively.
Blocks 930 , 1020 , and 1024 refer to I/O signal names and, in particular, the signal Names of the Bondout, the Platform, and those given by the User, respectively. The names of signals of the slice specification are read into block 930 Signal Name (Bondout) and becomes the default names for the Signal Name (Platform) 1020 along path 932 . If the name of the I/O signal is changed when further developing the platform, then that name may be propagated to Signal Name (User) 1024 along path 1022 . Thus the Signal Name (Bondout) 930 may be considered the default, and a chip developer can change the signal names at the platform level at Signal Name (Platform) 1020 and/or at the user level at Signal Name (User) 1024 . In any event, when the I/O signal name is defaulted from the Signal Name (Bondout) 930 or defaulted from the Signal Name (Platform) 1020 , the signal name in Signal Name (User) 1024 is also reflected in the Reset Signal Name ( 790 in FIG. 7 b ) along path 792 if the signal is a reset signal, or is reflected in changes in the oscillator source name FIG. 7A along path 758 . The signal names at the various levels, i.e., the Signal Name (Bondout) 930 , Signal Name (Platform) 1020 , and Signal Name (User) 1024 are checked by the RULES ENGINE to ensure that the name complies with industry, proprietary, syntactic conventions and requirements. The RULES ENGINE may also verify that the I/O signal names at any of these levels, i.e., bondout, platform, user, represent that the signal may be dedicated to test usage such as for JTAG, test insertion, tree optimization, etc. If, moreover, any of these I/O signals are intended to be used for reference voltage signals at either the platform or user level, changes in the names or other parameters will be propagated to the VREF (Platform) along path 914 and/or VREF (User) along path 922 .
By default, the RULES ENGINE loads all I/O buffers into Diffused I/O type 940 , but if there is a label to state that an I/O buffer is configurable, then that buffer is also loaded into the Configurable I/O type (Platform) 950 and the Configurable I/O type (User) 1040 . Configurable I/O type (Platform) 950 may be configured as an I/O buffer type for a Configurable I/O type (User) along path 954 or remain as an Configurable I/O type (Platform) 950 . The parameters associated with the I/O types 940 and/or 1040 include the I/O direction of which that I/O buffer is capable, i.e., can the I/O buffer be INOUT, IN, or OUT. The Rules Engine further is aware that some of the parameters are determined by the type of I/O buffer; an I/O buffer type is determined by, inter alia, its electrical characteristics, such as voltage levels, differentiality, etc. Examples of different types include HSTL, SSTL, LVDS, PECT, etc. Thus, the actual use, e.g., whether IN or OUT or INOUT, of a Diffused I/O buffer type 940 is recorded in I/O Use (Platform) 1054 along path 944 and/or in I/O Use (User) block 1058 along path 942 . Similarly, the actual I/O platform use of an I/O configurable buffer is indicated along path 1052 in block I/O Use (Platform), and the actual I/O use of a user's configurable I/O 1040 is indicated along path 1044 in I/O Use (User) 1058 . If a test feature is selected in Test Usage (Platform) 1066 for an I/O diffused buffer 940 , the RULES ENGINE verifies that the I/O buffer allows tests for a matching bump is differential signal pair. Similarly if the I/O buffer is input or output for a differential signal, the RULES ENGINE confirms that there are two rows (bumps) right next to each other and identifies the polarity. If an I/O buffer is selected for an I/O signal in a major power plane, the RULES ENGINE verifies that that the voltage level jof the signal is compatible with the power plane.
Also represented in FIGS. 9A and 9B are checks for the components used by the platform and the user. Each component is characterized by its type, its name, and its port. If a platform implements a component, that component type (platform) of block 960 is checked first to determine if the component type exists in the design along path 604 . The I/O buffer and the component type must be compatible, e.g., if the I/O buffer, whether diffused or configurable, is to be connected to a PLL, or an I/O hardmac, such as GIGABLAZE or HYPERPHY, then the RULES ENGINE verifies compatibility. If the component type is part of the user module, the RULES ENGINE verifies that this component type is allowable, is not a test signal, or a major power plane, such as along path 962 . If all these conditions on path 604 associated with block 960 , then along path 962 , the value may also be set in the component type (user) block 990 ; otherwise if used by the platform its name is tracked in block 970 along path 972 for the same parameters.
The RULES ENGINE and the TEMPLATE ENGINE are used to create instantiated and formatted shells used in the creation, the design, and the manufacture of semiconductor products. Data is obtained from a data base, preferably using the enumerated lists or input checking, such as described in CORRECT DATA ENTRY, that ensures correct data. The TEMPLATE ENGINE specifically addresses issues such as the syntax of the language and the structures common in hardware design used in semiconductor integrated circuit.
The TEMPLATE ENGINE and the RULES ENGINE described herein are part of a builder tool that automatically manages slice resources from an application set and builds RTL code for memories, I/Os, and clocks of a semiconductor product. In one embodiment, the builder tool uses input tables of specifications to assign I/Os, clocks, PLLs, and memories; other input techniques include notebooks of circuit diagrams, graphical representations of the architecture, etc. The builder tool can be installed as an application on any client or any server accessible through a network to a client computer. First, a user might select to create a design and then, in the preferred embodiment, a screen of the tool's selection tables as is shown in FIG. 10 is displayed. As is typical in a networked environment, the RULES ENGINE can be applied to multiple data files across a network.
In fact, the top module can be completely generated using the builder tool using the RULES ENGINE as described herein. Logical memories and clocks can be added and/or deleted. To add a logical memory/clock, the designer may click the Memories/Clocks and select Add on a menu bar of a graphical user interface. In one embodiment, a new row will be added to a memory/clocks specifications table. Logical memory/clocks may be deleted and upon deletion, the memory/clock will be deleted from its respective Memory/Clocks Specifications Table. Of course, more than one memory/clock may be deleted at a time by highlighting cells in multiple rows for the memories/clocks to be deleted.
Bus declarations may be entered easily using the builder tool. A bus is a group of input/output ports that share a common signal name. An bus can be declared by specifying a signal name having an individual bit in square brackets representing a starting index, for example, bus_name[5______]. A user could simply highlight a range of ports, assign a common base name, and then from a starting index, a user could simply increment or decrement the ports on that bus. Optionally, a user can manually change each port or use other copy/paste techniques. In one embodiment of the TEMPLATE ENGINE, one bit buses are not allowed; indices are contiguous, and the least significant bit is zero.
A screen shot of a resource viewer is shown in FIG. 11 . The resource viewer may list the technology and the name of the semiconductor platform. The technology of the chip, typically referring the gate length of the transistors, may be presented at 1302 , and the name slice at 1304 . The resource viewer 1300 has several windows which list the I/O resources 1306 available for development, the PLL resources 1324 available for development, the I/O resources of the coreware 1334 , i.e., the hardmacs and/or logical functions that are available for design, instantiated, and ready for use, and the memory resources 1344 . Each of these windows may have a pull-down window, hypertext links, or other known method to expand the view into the windows for a more complete lists of the factors and parameters affecting a particular resource. For I/O resources 1306 , the resource viewer 1300 may display how many signal I/Os have been used, and how many are available. For phase locked loops (PLLs) 1324 , hardmacs 1334 , and diffused memories 1344 , the resource viewer 1300 may display if a specific component is used or unused 1326 , 1358 , the type of component, and the physical reference of any diffused I/O components, e.g., 1330 , 1354 . For logical memories to be configured from the transistor fabric, the resource viewer may display how much transistor fabric has been used 1346 and how much is available 1348 . In some embodiments, there may be a limitation to the amount of transistor fabric that can be utilized for memory, e.g., only 25 percent.
An example of how to use a partially completed I/O table is shown in FIG. 12 ; a designer may wish to edit a signal. The designer first locates the signal to be edited in a row 1504 of the table and may change the name in the Signal Name (User) 1024 column if needed. Then, in the Config IO Type (User) 1040 column, the user may select the cell she/he wishes to configure and either selects an appropriate I/O buffer from the drop-down list or enter one in accordance with CORRECT DATA ENTRY. The RULES ENGINE will verify that the selected buffer is at the same voltage level as all other buffers on the same power segment, i.e., the buffer name indicates the voltage level of the buffer. For bidirectional buffers, I/O Use (Platform) 1054 which is indicated as INOUT, the designer may select how the I/O is going to be used in the I/O Use (User) 1058 column. Under the Component Type (User) 990 column, the chip designer may select the User Module (UM) option from the drop-down list which may appear in the cell. In accordance with the RULES ENGINE herein, if a chip designer (user) attempts to enter an illegal connection, an error dialog box will appear and the attempted modification may be ignored. Any of these methods of editing the contents of the specifications tables will invoke the algorithms that implement the RULES ENGINE to ensure that the modifications, additions, deletions are constantly updated and continuously valid throughout the design.
Using the Clock Specifications Table, a user may configure a clock from a PLL by first adding a clock to the table and in the Osc Source Type column, select or entering a PLL. In the Osc Source Name column, the user is requested to change the name to the desired PLL and, if desired, to change the clock name in the Clock Name field. The value in the Divider column is changed and will automatically change the clock frequency. Then the reset source is set; if the user wants the reset to come from a primary I/O, she/he is requested to enter the name from the Signal Name (User) column into the Reset Source column.
While the description provides embodiments of the invention, the embodiments are considered illustrative and by way of example only and are not intended to be limitative.
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A method to validate data used in a design of a semiconductor product. The method includes (a) reading resources of an application set defining the semiconductor product in a partially fabricated state comprising fabrication layers up to and including a lowest conductive layer (b) reading a user specification that (i) is developed based upon the application set at the partially fabricated state and (ii) establishes at least one upper conductive layer added to the application set that completes the design of the semiconductor product, (c) allocating a new resource from the user specification to the design of the semiconductor product, said new resource having multiple parameters, (d) validating the allocation of the new resource against the resources of the application set and (e) propagating the allocation of the new resource and the parameters throughout a description of the semiconductor product.
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REFERENCE TO CROSS-RELATED APPLICATION & PRIORITY CLAIM
This application claims priority to and is a continuation of U.S. patent application Ser. No. 10/966,963, filed 15 Oct. 2004, now U.S. Pat. No. 7,722,951, which is incorporated herein by reference as if fully set forth below.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to the field of insulator coatings, and specifically to a superhydrophobic surface coating for use as a protective coating for power systems.
2. Description of Related Art
Conventional high-voltage devices such as bushings, connectors, and capacitors use a combination of non-conductive and conductive materials to construct desired high-voltage structures. The nonconductive materials provide a dielectric barrier or insulator between two electrodes of different electrical potential.
The bulk of power delivery from the generating sites to the load centers is accomplished by overhead lines. To minimize line losses, power transmission over such long distances is more often carried out at high voltages (several hundred kV). The energized high voltage (HV) line conductors not only have to be physically attached to the support structures, but also the energized conductors have to be electrically isolated from the support structures. The device used to perform the dual functions of support and electrical isolation is the insulator.
High voltage insulators are used with transmission and distribution systems, including power transmission lines, for example at locations where the lines are suspended. Known insulators include ceramics, glass and polymeric materials. Ceramic and glass insulators have been used for over 100 years. The widespread use of polymeric insulators began in North America during the 1970s. A currently popular line of insulators are room temperature vulcanized (RTV) silicone rubber high voltage insulator coatings.
Ceramic insulators generally include clay ceramics, glasses, porcelains, and steatites. The ceramic is produced from the starting materials kaolin, quartz, clay, alumina and/or feldspar by mixing the same while adding various substances in a subsequent firing or sintering operation. Polymeric materials include composites (EPDM rubber and Silicone rubber) and resins.
A wide variety of manufacturing techniques can be employed to construct insulators of the desired shape. Some of the processes that are most often used include machining, molding, extrusion, casting, rolling, pressing, melting, painting, vapor deposition, plating, and other free-forming techniques, such as dipping a conductor in a liquid dielectric or filling with dielectric fluid. The selection process must take into account how one or both of the electrodes made from conductive material will be attached or adjoined to the insulator.
In long-term use, an insulator is subject to a greater or lesser degree of superficial soiling, depending on the location at which it is used, which can considerably impair the original insulating characteristics of the clean insulator. Such soiling is caused for example by the depositing of industrial dust or salts or the separating out of dissolved particles during the evaporation of moisture precipitated on the surface. In many parts of the world, insulator contamination has become a major impediment to the supply of electrical power. Contamination on the surface of insulators gives rise to leakage current, and if high enough, flashover.
One problem afflicting high voltage insulators used with transmission and distribution systems includes the environmental degradation of the insulators. Insulators are exposed to environment pollutants from various sources. It can be recognized that pollutants that become conducting when moistened are of particular concern. Two major sources of environmental pollution include coastal pollution and industrial pollution.
Coastal pollution, including salt spray from the sea or wind-driven salt-laden solid material such as sand, can collect on the insulator's surface. These layers become conducting during periods of high humidity and fog. Sodium chloride is the main constituent of this type of pollution.
Industrial pollution occurs when substations and power lines are located near industrial complexes. The power lines are then subject to the stack emissions from the nearby plants. These materials are usually dry when deposited, then may become conducting when wetted. The materials will absorb moisture to different degrees. Apart from salts, acids are also deposited on the insulator.
Of course, both sources of pollution can exist. For example, if a substation is situated near to the coast, it will be exposed to a high saline atmosphere together with any industrial and chemical pollution from other plants situated in close proximity.
The presence of a conducting layer on the surface of an insulator can lead to pollution flashover. In particular, sufficient wetting of the dry salts on the insulator surface is required to from a conducting electrolyte. The ability of a surface to become wet is described by its hydrophobicity. Ceramic materials and some polymeric materials such as EDPM rubber are hydrophilic, that is, water films out easily on its surface. In the case of some shed materials such as silicone rubber, water forms beads on the surface due to the low surface energy.
When new, the hydrophobic properties of silicone rubber are excellent; however, it is known that severe environmental and electrical stressing may destroy this hydrophobicity.
Current remediation techniques for environmental degradation of a high voltage insulator include washing, greasing and coatings, among others. Substation or line insulators can be washed when de-energized or when energized. Cleaning with water, dry abrasive cleaner, or dry ice can effectively remove loose contamination from insulator, but it is expensive and labor intensive. It is not uncommon that washings involve shutting down the power once every two weeks in winter time and once per week in summer when doing this kind of maintenance. This common occurrence of de-energization simply is not preferable.
Mobile protective coatings, including oils, grease and pastes surface treatment, can prevent flashover, but have damaging results to the insulator during dry band arcing. A thin layer of silicone grease, when applied to ceramic insulators, increases the hydrophobicity of the surface. Pollution particles that are deposited on the insulator surface are also encapsulated by the grease and protected from moisture. A disadvantage of greasing is that the spent grease must be removed and new grease applied, typically annually. Grease-like silicone coating components, usually compounded with alumina tri-hydrate (ATH), provide a non-wettable surface and maintain high surface resistance. Thus, greasing can greatly reduce maintenance costs when viewed against washings, but the substation has to remove the old grease compounds from the equipment, and then re-apply the new grease compound annually.
Fluorourethane coatings were developed for high voltage insulators, but the field test is not successful, and its adhesion to insulators has been a problem.
Since the 1970s, silicone room temperature vulcanizing (RTV) coatings have gained considerable popularity, and become the major products available in the market, such as Dow Corning's SYLGARD High Voltage Insulator Coatings, CSL's Si-Coat HVIC, and Midsun's 570 HVIC. Service experience has indicated that of the various types of insulator coatings, the time between maintenance and RTV coating reapplication is the longest.
Room temperature cured silicone rubber coatings are available to be used on ceramic or glass substation insulators. These coatings have good hydrophobic properties when new. Silicone coatings provide a virtually maintenance-free system to prevent excessive leakage current, tracking, and flashover. Silicone is not affected by ultraviolet light, temperature, or corrosion, and can provide a smooth finish with good tracking resistance.
Silicon coatings are used to eliminate or reduce regular insulator cleaning, periodic re-application of greases, and replacement of components damaged by flashover. They appear to be effective in many types of conditions, from salt-fog to fly ash. They are also useful to restore burned, cracked, or chipped insulators.
SYLGARD is one type of silicone coatings, and is marketed to restrict the rise in leakage currents and protect the insulators against pollution induced flashovers. The cured SYLGARD coating has a high hydrophobicity. This hydrophobic capability is of prime importance because it is this factor that controls the degree of wetting of the contaminants, and thereby the amount of surface leakage current increase. Moisture on the insulator surface will form in droplets and by so doing will prevent the surface pollution from becoming wet and producing a conductive layer of ionisable materials that lead to increased leakage, dry band arcing and eventual flashovers.
In addition, there are a certain percentage of polymer molecules that exist within the cured rubber as low molecular weight free fluid. These molecules are known as “cyclics”. The free fluids are easily able to migrate to the surface of the coating and, as pollutants fall on the surface, they in turn are encapsulated and rendered non conductive and somewhat hydrophobic.
If leakage currents are controlled, there will be no arcing. If there is an extreme weather event then it may be that, for a time, the SYLGARD coating cannot control the surface leakage currents. In this case SYLGARD also provides a high degree of surface arc resistance. Incorporated into the formulation is an alumina trihydrate (ATH) filler, which releases H 2 O when it becomes hot and consequently resists the degradative effects of high temperatures, resulting from exposure of the coating to arcing.
However, none of the above techniques prevent contamination, such as dust, accumulation on coating surfaces, and none of the above techniques has satisfactory performance in heavy contamination environments.
Although high voltage insulator coatings are known, as discussed above, a need yet exists for a superior product that can minimize the maintenance necessary for conventional coatings. An HVIC that is self-cleaning and has an expected longer life than conventional coatings would be beneficial.
The abovementioned criteria are satisfied in the natural world. The phenomenon of the water repellency of plant leaf surfaces has been known for many years. The Lotus Effect is named after the lotus plant. The Lotus Effect implies two indispensable characteristic properties: superhydrophobicity and self-cleaning. Superhydrophobicity is manifested by a water contact angle larger than 150°, while self-cleaning indicates that particles of dirt such as dust or soot are picked up by the drop of water as they roll off and removed from the surface.
It is recognized that when a water drop is placed on a lotus plant surface, the air entrapped in the nano surface structures prevents the total wetting of the surface, and only a small part of the surface, such as the tip of the nano structures, can contact with the water drop. This enlarges the water/air interface while the solid/water interface is minimized. Therefore, the water gains very little energy through adsorption to compensate for any enlargement of its surface. In this situation, spreading does not occur, the water forms a spherical droplet, and the contact angle of the droplet depends almost entirely on the surface tension of the water.
Although the Lotus Effect was discovered in plants, it is essentially a physicochemical property rather than a biological property. Therefore, it is possible to mimic the lotus surface structure. To mimic the lotus surfaces, a Lotus Effect surface should be produced by creating a nanoscale rough structure on a hydrophobic surface, coating thin hydrophobic films on nanoscale rough surfaces, or creating a rough structure and decreasing material surface energy simultaneously. Up to now, many methods have been developed to produce hydrophobic surfaces with nano-scale roughness.
Thus, surfaces with a combination of microstructure and low surface energy are known to exhibit interesting properties. A suitable combination of structure and hydrophobicity renders it possible that even slight amounts of moving water can entrain dirt particles adhering to the surface and clean the surface completely. It is known that if effective self-cleaning is to be obtained on an industrial surface, the surface must not only be very hydrophobic but also have a certain roughness. Suitable combinations of structure and hydrophobic properties permit even small amounts of water moving over the surface to entrain adherent dirt particles and thus clean the surface. Such surfaces are disclosed in, for example, WO 96/04123 and U.S. Pat. No. 3,354,022).
European Pat. No. 0 933 380 discloses that an aspect ratio of >1 and a surface energy of less than 20 mN/m are required for such self-cleaning surfaces. The aspect ratio is defined to be a quotient of a height of a structure to a width of the structure.
Other prior art references include PCT/EP00/02424, that discloses that it is technically possible to render surfaces of objects artificially self-cleaning. The surface structures, composed of protuberances and depressions, required for the self-cleaning purpose have a spacing between the protuberances of the surface structures in the range of 0.1 to 200 μm and a height of the protuberances in the range from 0.1 to 100 μm. The materials used for this purpose must consist of hydrophobic polymers or a durably hydrophobized material. Detergents must be prevented from dissolving from the supporting matrix. As in the documents previously described, no information is given either on the geometrical shape or radii of curvature of the structures used.
EP 0 909 747 teaches a process for producing a self-cleaning surface. The surface has hydrophobic elevations of height from 5 to 200 μm. A surface of this type is produced by applying a dispersion of powder particles and of an inert material in a siloxane solution, followed by curing. The structure-forming particles are therefore secured to the substrate by an auxiliary medium.
Methods for producing these structured surfaces are likewise known. In addition to molding these structures in a fashion true to detail by way of a master structure using injection molding or by an embossing method, methods are also known which use the application of particles to a surface (e.g. see U.S. Pat. No. 5,599,489). This process utilizes an adhesion-promoting layer between particles and bulk material. Processes suitable for developing the structures are etching and coating processes for adhesive application of the structure-forming powders, and also shaping processes using appropriately structured negative molds.
However, it is common to all these methods that the self-cleaning behavior of these surfaces is described by a very high aspect ratio.
Plasma technologies are widely utilized for processing of polymers, such as deposition, surface treatment and etching of thin polymer films. The advantages of using plasma techniques to prepare the Lotus Effect coating include that plasma technologies have been extensively employed in surface treatment processes in the electronic industry. Fabricating the Lotus Effect coating on various surfaces with plasma can be easily transferred from research to scale up production. Further, plasma-based methods can be developed into a standard continuous/batch process with low cost, highly uniform surface properties, high reproducibility and high productivity.
Exposure to sunlight and some artificial lights can have adverse effects on the useful life of polymer coatings. UV radiation can break down the chemical bonds in a polymer. Since photodegradation generally involves sunlight, thermal oxidation takes place in parallel with photooxidation. The use of antioxidants during processing is not sufficient to eliminate the formation of photoactive chromospheres. UV stabilizers have been applied widely and the mechanism of stabilization of UV stabilizers belong to one or more of the following: (a) absorption/screening of UV radiation, (b) deactivation (quenching) of chromophoric excited states, and (c) free-radical scavengers, and (d) peroxide decomposers.
Since transmission lines are often in remote locations that are hard to reach, it is desirable that once the line has been constructed, it will work satisfactorily, without maintenance, for the expected life of the line, generally exceeding 30 years. Therefore, it can be seen that a need yet exists for a superior HVIC that utilizes a coating surface exhibiting “Lotus Effect” properties, including superhydrophobicity and self-cleaning.
BRIEF SUMMARY OF THE INVENTION
The present invention comprises a method to prepare a superhydrophobic coating with enhanced UV stability as a (super) protective coating for external electrical insulation system applications. Coatings of this type can have a wide range of uses and the substrate to which the same is applied can be many insulating materals, including polymers, ceramics, metals and glass.
In particular, although not necessarily exclusive, by coating and etching polymer coating materials, the present invention provided a method to prepare superhydrophobic coatings and prevent the contamination problems of conventional external electrical insulation systems. The UV stability of the coating systems was improved by various UV stabilizers and UV absorbors.
The present invention utilizes a Lotus Effect coating a protective coating for insulating materials. The protective coating keeps the surface of external electrical insulation systems dry and clean, thus minimizing chances for surface degradation and surface contaminant-induced breakdown of the insulation systems, thus significantly enhancing their performance.
The present invention employs various plasma and chemical etching techniques to prepare superhydrophobic surfaces. The following polymer photostabilization methods were provided in the present invention to enhance the UV stability of the Lotus Effect coatings.
UV screens: It is evident that opaque pigments can stabilizer the polymer by screening the incident UV photos of high energy.
UV absorbers: A very simple way to protect adhesives against UV light is to prevent UV absorption, i.e. reducing the amount of light absorbed by chromophores. The UV absorbers, such as some orthohydroxybenzophenones derivatives, have a common structure feature that is responsible for their activity as efficient UV stabilizers, namely, a strong intramolecular hydrogen bond. UV absorbers have high extinction coefficient in the 290-400 regions.
Excited-state quenchers: excited-state quenchers interact with an excited polymer atom by indirect energy absorption. The quenchers bring the high-energy chromophore back to ground state by absorbing the energy and then dissipating the energy harmlessly before the energy can degrade. Organometal complexes or chelates such as those based on nickel are most effective.
Hindered amine light stabilizers: Today, the most common category of light stabilizers consists of what are known as hindered amine light stabilizers (abbreviated as HALS). They are derivatives of 2,2,6,6-tetramethyl piperidine and are extremely efficient stabilizers against light-induced degradation of most polymers. HALS does not absorb UV radiation, but acts to inhibit degradation of the polymer. They slow down the photochemically initiated degradation reactions, to some extent in a similar way to antioxidants.
One advantage of the hindered amine light stabilizers is that no specific layer thickness or concentration limits needs to be reached to guarantee good results. Significant levels of stabilization are achieved at relatively low concentrations. HALS' high efficiency and longevity are due to a cyclic process wherein the HALS are regenerated rather than consumed during the stabilization process.
The present invention preferably comprises superhydrophobic coating surfaces as protective coatings for external insulation system applications, and superhydrophobic coating surfaces generally that include UV screens, UV absorbers, UV free-radical scavengers and/or anti-oxidants.
The superhydrophobic coating can include polymer materials, which include homopolymers such as PTFE, polybutadiene, polyisoprene, Parylenes, polyimide, silicones, and copolymers such as PBD, ABS, polybutadiene-block-polystyrene, silicone-polyimides. The polymer materials can further include unsaturated bonds of polybutadiene or polyisoprene and their copolymers.
The polymer materials can be applied by any or any combination of spin coating, solvent casting, dipping, spraying, plasma deposition or chemical vapor deposition. The superhydrophobic coating can comprise UV screens, UV absorbers, UV free-radical scavengers and anti-oxidants, preferably with a loading level of 0.01-20 wt. %.
The UV screens can include one or a combination of carbon black, titanium dioxide, barium, zinc oxide, and colored pigments include iron oxide red and copper and all transition metal phthalocyanines.
The UV absorbers can include one or a combination of substituted benzophenones and benzotriazoles, plus others such as cyanoacrylate derivatives, salicylates, and substituted oxanilides
The UV free-radical scavengers can include one or a combination of free-radical scavengers such as esters of 3,5-di-t-butyl-4-hydroxybenzoic acid and derivatives of 3,5,-di-t-butyl-4-hydroxy-benzyl-phosphonic acid and other hindered amine light stabilizers.
The anti-oxidants can include one or a combination of chain-breaking antioxidants such as hindered phenols or alkylarylamines, peroxide-decomposing antioxidants such as organosulfur compounds, metal deactivators, and color inhibitors such as tertiary phosphates or phosphonates.
The superhydrophobic coating can be applied on many surfaces, such as metal, glass, ceramics, semiconductors, flexible surface such as paper and textiles and polymers.
The superhydrophobic surface preferably incorporates an irregular surface structure that is produced by plasma such as those generated by radio frequency, microwaves and direct current. The plasma may be applied in a pulsed manner or as continuous wave plasma. Typically, the plasmas can be operated at any or any combination of low pressure, atmospheric or sub-atmospheric pressures.
Compared with silicone high voltage insulating coatings, the present Lotus Effect HVIC has the following advantages, among others,
a higher surface hydrophobicity to repel water; due to its self-cleaning property, contaminants cannot accumulate on its surface, therefore, it eliminates the danger of arcing and flashover; it eliminates the need for repeated water washing or greasing, which results in significant savings in maintenance and replacement costs; because it does not contain Alumina Hydrate particles as a filler as other HVICs, it prevents dry band arcing and performs better in contaminated conditions.
Thus, one objective of the present invention, therefore, is to provide a self-cleaning superhydrophobic surface on external insulation systems to prevent contamination problems, and to provide a process for its production. The nanoscale structure and low surface energy of the superhydrophobic coating reduce the adhesion between dust particles and the coating surface, and the dust particles can be removed by water droplet when it rains. Therefore the contamination problem of insulating materials will be prevented.
Another objective of the invention is to provide superhydrophobic coating systems that have good stability under UV exposure. Various UV stabilizers and UV absorbers were incorporated into the coating systems to enhance their UV stability while maintaining its superhydrophobicity.
These and other objects, features and advantages of the present invention will become more apparent upon reading the following specification in conjunction with the accompanying drawing figures.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a SEM image of PTFE, wherein untreated, the water contact angle is 113°.
FIG. 2 is a SEM image of oxygen plasma etched PTFE, etched for approximately 15 minutes, wherein the water contact angle is 150°.
FIG. 3 is a SEM image of polybutadiene, untreated
FIG. 4 is a SEM image of SF 6 plasma etched polybutadiene, etched for approximately 10 minutes.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The present invention preferably provides a surface which has an artificial surface structure and low surface energy. While the present invention preferably comprises systems and methods for providing a self-cleaning superhydrophobic surface on high voltage insulators used with transmission and distribution systems, the invention can be used in other environments.
The present invention further comprises superhydrophobic coating systems that have good stability under UV exposure, for use not just in the voltage insulators used with transmission and distribution systems. A superhydrophobic coating system comprising UV stabilizers and/or UV absorbers is disclosed.
FIGS. 1 and 2 show the micro structure on PTFE surface after oxygen plasma etching, which enhances the surface hydrophobicity and reduces the adhesion between dust particles and PTFE surface. FIGS. 3 and 4 show the nanoscale structure on polybutadiene surface after SF 6 plasma etching. The water contact angle on this surface is above 160°.
Surfaces that are rough tend to be more hydrophobic than smooth surfaces, because air can be trapped in the fine structures, and reduce the contact area between the water and solid. The self-cleaning property of a Lotus Effect surface indicates that particles of dirt such as dust or soot are picked up by a drop of water as they roll off and are removed from the surface.
Self-cleaning is determined by the adhesion force between particles and Lotus Effect surface and the surface wetting properties. When a water droplet rolls over a particle, the surface area of the droplet exposed to air is reduced and energy through adsorption is gained. The particle is removed from the surface of the droplet only if a stronger force overcomes the adhesion between the particle and the water droplet. On a given surface, this is the case if the adhesion between the particle and the surface is greater than the adhesion between the particle and the water droplet. If the water droplet easily spreads on the surface (low water contact angle), the velocity of the droplet running off a surface is relatively low. Therefore, particles are mainly displaced to the sides of the droplet and re-deposited behind the droplet, but not removed. If the water droplet does not spread on the surface (high water contact angle), the water runs off the surface with considerable velocity. It is very likely that particles are carried along with the moving liquid front, a mechanism that was also presumed responsible for the removal of microorganisms from leaf surfaces.
Depending on the hydrophobicity of surface materials and the type of surface structures, the structure scale of Lotus Effect surfaces range from nano to micrometers. For the present invention, to achieve the self-cleaning action of dust particles, the hydrophobic surface preferably should have a surface structure from 50 nm to 200 μm, preferably from 100 nm to 20 μm. Lotus Effect surfaces can be prepared by several approaches. Typically, the polymer material can be applied in any conventional manner to suit particular method requirements and, for example, can include applications by spin coating, solvent casting, dipping spraying, plasma deposition or chemical vapor deposition.
The polymer material can comprise a number of components, including but not limited to, homopolymer and copolymers. These polymeric components may occur singly, in combination with one another, or in the presence of non-polymeric additives. The components of polymer blends may be miscible or immiscible. The polymer material can be fluorinated polymer, such as PTFE, or includes unsaturated bonds that can be fluorinated by following plasma treatment. Two such polymers are polybutadiene and polyisoprene. In addition, the coating may comprise additional layers, supplementary to the outermost surface layer, which can consist of any combination of materials.
The superhydrophobic surface of the coating can be achieved by plasma etching. Suitable plasmas for use in the method of the invention include non-equilibrium plasma such as those generated by radio frequency or microwaves. The plasma may be applied in pulsed manner or a continuous manner. The etching gas for PTFE is oxygen and the etching gases for other polymer materials containing unsaturated bonds are SF 6 , CHF 3 or CF 4 .
In another preferred embodiment of the present invention, a Lotus Effect coating can be fashioned by suspending inert micro (5-200 micrometers) particulates, which can be, for example, PTFE, PP, PE, ceramic or clay, in various silicon-solvent solutions. The solvents used can be common solvents, such as 1-methoxy-2-propanol. The concentration of the inert particulates can be 5-30 wt %, and the concentration of silicon can be 1-20 wt %.
The suspensions are then spin or spray coated on various insulating materials. Following a curing processing of the silicon materials (depending on the silicon materials, the curing temperature varies from room temperature to 150 degree C.), the micro particulates were fixed on surface and give superhydrophobicity.
Exposure to sunlight and some artificial lights can have adverse effects on the useful life of coating materials. UV radiation can break down the chemical bonds in a polymer. This process is called photodegradation and ultimately causes cracking, chalking, color changes and the loss of physical properties. Since photodegradation generally involves sunlight, thermal oxidation takes place in parallel with photooxidation. To counteract the damaging effect of UV light, UV stabilizers are used to solve the degradation problems associated with exposure to sunlight. The present invention provides a method to integrate various UV absorbers and UV stabilizers into the coating systems to enhance their UV stability while maintaining their superhydrophobicity.
For the present invention, single photostabilization method or a combination of different photostabilization stabilizers were employed. Preferably, UV stabilizers and anti-oxidants are dissolved in solvent and mixed with polybutadiene solutions. The solution that contains polybutadiene and UV stabilizers are spin/dip coated on insulating materials, and etched with plasma. The preferable concentration of UV stabilizers and anti-oxidants is 0.01 to 20 wt % in the coatings after drying in air.
A superhydrophobic and self-cleaning Lotus Effect coating is invaluable to high voltage applications, because it prevents the accumulation of contaminants on the surface of the insulators, which can produce a conductive layer when wet, and then lead to an increase in leakage currents, dry band arcing, and ultimately flashover. The present coating also offers resistance to atmospheric and chemical degradation (the coated insulators remain unaffected by salt air, airborne pollutants, rain or humidity). Lotus Effect coatings also exhibits high-tracking resistance to reduce damage during salt storms or other severe contamination events. It can be used in applications including: glass, porcelain and composite insulators where improved surface dielectric properties are needed, line and station insulators, as well as bushings, instrument transformers and related devices, as well as other applications requiring tracking resistance.
COMPARATIVE EXAMPLES
Example 1
PTFE, also known as Teflon (trademark by DuPont), has outstanding properties. PTFE is non-sticky; very few solid substances can permanently adhere to a PTFE surface. It has a low coefficient of friction (the coefficient of friction of PTFE is generally in the range of 0.05 to 0.20). In addition, it has good heat and chemical resistances. It also has good cryogenic stability at temperatures as low as −270° C.
Coating PTFE on various surfaces, such as glass, ceramic and metal, has become a mature industrial process. Lotus Effect surfaces created by plasma etching of PTFE combine superhydrophobicity with the excellent properties of PTFE coatings and can withstand harsh environmental conditions. The preferable etching gas is oxygen. The preferable etching resonant frequency is from 100 K to 13.6 MHz. The preferable etching power is from 20 W to 300 W. The preferable etching time is from 5 minutes to 30 minutes.
During plasma treatment, the needle-like structures appeared and the void increased between the needle-like structures. Such a surface morphology entraps air bubbles and reduces the wetting area on the surface when it comes in contact with water drops, therefore increasing the surface hydrophobicity.
As an example, PTFE nonstick coatings are prepared on insulating materials by a two-coat (primer/topcoat) system. Oxygen plasma etching experiments were performed by using a radio-frequency Reactive Ion Etcher (RIE). The specimens were placed on a horizontal metal support. The reactor chamber was purged with oxygen and evacuated to 2 mTorr twice, to remove nitrogen from the chamber before the plasma treatment. The plasma parameters were as follows: resonant frequency 13.6 MHz, power 100 W, pressure 150 mTorr, and oxygen gas flow 8 sccm. The plasma treatment time is 15 minutes. Superhydrophobic PTFE coatings with water contact angle above 150° were prepared.
FIGS. 1 and 2 show the surface morphology of the etched PTFE coatings.
Example 2
The Lotus Effect coating can also be produced by plasma fluorination of polybutadiene films. The C═C bonds on the surface can be easily activated and fluorinated. Polybutadiene is a relatively inexpensive material compared with other materials and it can be easily applied to metal, glass, ceramics, semiconductors, paper, textile, and other polymeric surfaces. Polybutadiene was dissolved in solvent and spin/dip coated onto insulating materials. The coatings were dried in air and etched with plasma to prepare superhydrophobic surfaces. Polybutadiene films are thermal or UV curable after fluorination and their surface hardness increases with better durance and reliability, while maintaining the surface superhydrophobicity.
The coating thickness was adjusted by controlling polybutadiene solution concentration and the rotation speed of spin coating. The preferable thickness of the coating is from 200 nm to 50 μm. The preferable etching gas is SF 6 . The preferable etching resonant frequency is 13.6 MHz. The preferable etching power is from 20 W to 300 W. Superhydrophobic coating with water contact angle between 155° to 170° can be prepared with this method.
The polybutadiene was dissolved in toluene at 10 wt %, and the solution was then spin-coated on glass and silicon substrates. The thickness of the films was about 5 μm. and it can be controlled by controlling the solution concentration and spin coating processes. These films were subsequently annealed at 90° C. under vacuum for 60 min to remove the solvent. Reactive Ion Etching (RIE) of three different gases (CF 4 , CHF 3 , SF 6 ), and Inductive Coupled Plasma (ICP) of CF 4 were employed to treat the polybutadiene films. A stable porous surface with water contact angle above 160° was obtained, and a small sliding angle was also observed. The surfaces were subsequently cured in air at 150° for 1 hour. The SEM images of SF 6 etched polybutadiene thin films are shown in FIGS. 3 and 4 .
Example 3
Single or a combination of UV stabilizers was dissolved in the polybutadiene and toluene solution in Example 2. The polybutadiene and UV stabilizer solution was dip/spin coated on insulating materials to form thin film coatings. These films were subsequently annealed at 90° C. under vacuum for 60 min to remove the solvent. The preferable concentration of UV stabilizer is from 0.01 to 20 wt %. Reactive Ion Etching (RIE) of three different gases (CF 4 , CHF 3 , SF 6 ), and Inductive Coupled Plasma (ICP) of CF 4 were employed to treat the films, and superhydrophobic surface were prepared.
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Methods of reducing pollution problems in power lines systems are disclosed herein. In one embodiment, the method comprises applying Lotus Effect materials as a (superhydrophobicity) protective coating for external electrical insulation system applications. Further disclosed are methods of fabricating/preparing Lotus Effect coatings. Selected inorganic or polymeric materials are applied on the insulating material surface, and stable superhydrophobic coatings can be fabricated. Various UV stabilizers and UV absorbers can be incorporated into the coating system to enhance the coating's UV stability. Other aspects, features, and embodiments are also discussed and claimed.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation application of application Ser. No. 13/772,232 filed on Feb. 20, 2013. This patent application is related to a U.S. Pat. No. 8,715,005 B2, issued on May 6, 2014, and entitled “HIGH SPEED HIGH DENSITY CONNECTOR ASSEMBLY,” which is assigned to the same assignee as this application. This application further relates to the copending applications with Ser. Nos. 14/592,434 and 14/592,855.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a high speed high density connector assembly, and more particularly, to a high speed high density connector assembly having stacked contact wafers that are completely shielded.
2. Description of the Prior Art
Many prior art references disclose high speed high density connector assemblies with shielding structures. U.S. Pat. No. 6,709,294 B1, issued to Cohen et al. on Mar. 23, 2004, discloses an electrical connector having electrical conductors in a plurality of rows. Each of the plurality of rows includes a housing and a plurality of electrical conductors. Each electrical conductor has a first contact end connectable to a printed circuit board, a second contact end, and an intermediate portion therebetween that is disposed within the housing. The housing includes a first region surrounding each of the plurality of electrical conductors, the first region made of insulative material and extending substantially along the length of the intermediate portion of the electrical conductors. The housing also includes a second region adjacent the first region and extending substantially along the length of the intermediate portion of the electrical conductors. The second region is made of a material with a binder containing conductive fillers providing shielding between signal conductors. Furthermore, in discussing background art in U.S. Pat. No. 6,709,294, it is mentioned that a solution is introduced to provide shields through plastics coated with metals, but there are no combination of readily available and inexpensive metals and plastics that can be used, such as the plastic lacks desired thermal or mechanical properties, available plating techniques are not selective, etc.
U.S. Pat. No. 6,471,549 B1, issued to Lappohn on Oct. 29, 2002, discloses a shielded plug-in connector. The plug-in connector has a jack-in-blade strip having at least one first contact element and an edge connector having at least one second contact element corresponding to the first contact element. The edge connector, on or in its outer body areas, has at least partially shielding sheets. Shielding of the plug-in connector is achieved by, in addition to the shielding sheets provided on the edge connector, a shielding group with at least one first element arranged in the jack-in-blade strip. The first element of the shielding group is a base part in the form of a U-shaped rail. The shielding sheets on the edge connector have a planar body and angled stays. Two of the angled stays and a portion of the planar body between the two angled stays form a counterpart to the base part, wherein the counterpart and the base part together substantially encapsulate the first and second contact elements.
U.S. Pat. No. 7,581,990 B2, issued to Kirk et al. on Sep. 1, 2009, discloses a waferized electrical connector incorporating electrically lossy material selectively positioned to reduce crosstalk without undesirably attenuating signals. Wafer may be formed in whole or in part by injection molding of material to form its housing around a wafer strip assembly. A two shot molding operation may be adopted, allowing the housing to be formed of two types of material having different material properties, namely an insulative portion being formed in a first shot and lossy portion being formed in a second shot. The housing may include slots that position air, or create regions of air, adjacent signal conductors in order to provide a mechanism to de-skew a differential pair of signal conductors.
OBJECTS OF THE INVENTION
A main object of the present invention is to provide a high speed high density electrical connector assembly with improved shielding performance.
The present invention first provides an electrical connector comprises a conductive body, and a plurality of contact modules mounted on the body, each of the contact modules comprising a plurality of contacts, a shielding member and an insulator fixing the contacts. The conductive body electrically connects with the shielding member and is insulated from the contacts.
The present invention secondly provides an electrical connector assembly comprising: a first connector adapted to be mounted onto a first printed circuit board, the first connector comprising: a first body; and a plurality of first contact modules mounted to the first body, each of the first contact modules comprising a first wafer, a plurality of first contacts mounted on the first wafer, a first shielding member mounted on the first wafer, and a plurality of first insulators fixing the first contacts; and a second connector adapted to be mounted onto a second printed circuit board and adapted for being mated with the first electrical connector, the second connector comprising: a second body; and a plurality of second contact modules mounted to the second body, each of the second contact modules comprising a plurality of second contacts, a second shielding member, and a second insulator fixing the second contacts; wherein the first body is conductive and electrically connects with the first shielding members, and the second body is conductive and electrically connects with the second shielding members, the first body electrically connecting with the second body.
BRIEF DESCRIPTION OF THE DRAWINGS
The features of this invention which are believed to be novel are set fourth with particularity in the appended claims. The invention, together with its objects and the advantages thereof, may be best understood by reference to the following description taken in conjunction with the accompanying drawings, in which like reference numerals identify like elements in the figures and in which:
FIG. 1 is a perspective view of a connector assembly of according to a first embodiment of the present invention;
FIG. 2 is a cross-section view of the electrical connector system when cut in a line II-II shown in FIG. 1 ;
FIG. 3 is a perspective view of the stacked contact wafers with one contact wafer being exposed shown in FIG. 1 ;
FIG. 4 is a perspective view of two contact modules shown in FIG. 1 , one in assembled condition and the other in exposed condition;
FIG. 5 showing two contact wafers of a plug according to a second embodiment of the present invention, one in assembled condition and the other in exposed condition;
FIG. 6 showing two contact modules of a header according to a second embodiment of the present invention, one in assembled condition and the other in exposed condition;
FIG. 7 is a perspective view of a connector assembly of according to a third embodiment of the present invention;
FIG. 8 is a cross-section view of the electrical connector system when cut in the line VIII-VIII shown in FIG. 7 ;
FIG. 9 is a partially exploded view of a header shown in FIG. 7 ;
FIG. 10 is a partially exploded view of a plug shown in FIG. 7 ;
FIG. 11 is another partially exploded view of the plug shown in FIG. 7 in a different viewpoint;
FIG. 12 is a partially exploded view of a header of a connector assembly according to a fourth embodiment of the present invention;
FIG. 13 is a partially exploded view of a plug of a connector assembly according to the fourth embodiment of the present invention;
FIG. 14 is a partially exploded view of a header of a connector assembly according to a fifth embodiment of the present invention;
FIG. 15 is a partially exploded view of a plug of a connector assembly according to the fifth embodiment of the present invention;
FIG. 16 showing a first method of making the contact wafer shown in FIG. 1 ;
FIG. 17 showing a second method of making the contact wafer shown in FIG. 1 ; and
FIG. 18 showing a third method of making the contact wafer shown in FIG. 1 .
DETAILED DESCRIPTION OF THE INVENTION
Reference will now be made to the drawing figures to describe the present invention in detail.
FIGS. 1-4 show a connector assembly according to a first embodiment of present invention. The connector assembly 1 is shown to connect a daughter card (not shown) to a backplane (not shown). The connector assembly 1 includes a plug 10 mounted onto the daughter card and a header 20 mounted onto the backplane.
The plug 10 includes a conductive front housing 11 and a number of contact wafers 12 stacked along a transverse direction and mounted to a rear face of the front housing 11 . The plug 10 defines a mounting face 17 adapted to be mounted onto the daughter card. The header 20 includes a mounting face 27 adapted to be mounted onto the backplane.
The front housing 11 is made from die casting metal or conductive plastic, or insulating piece plated with metal plating. In a preferred embodiment, the front housing 11 is made from thermoplastic plated with metal plating, such as Chromium, Copper, Tin and Gold. The front housing 11 defines a front face 13 forwardly facing the header 20 , a rear face 14 opposite to the front face 13 and a number of holes 15 extending through the rear face 14 and the front face 13 .
Each of the wafers 12 includes a conductive board 120 defining mutual opposite first face and second face, four pairs of first signal contacts 121 , four first insulating holders 122 respectively fixing the pairs of first signal contacts 121 , a first shielding plate 123 , and four first insulating protectors 124 assembled to the conductive board 120 . Each pair of first signal contacts 121 are insert-molded with one corresponding first insulating holder 122 to form a contact module (not labeled), and thus there are four contact modules in each wafer 12 in each wafer 12 . The first shielding plate 123 has a planar portion 150 and eight grounding feet 151 extending downwardly from the planar portion 150 . The conductive board 120 is electrically connected to the first shielding plate 123 and connected to the daughter card through grounding feet 151 of the first shielding plate 123 . The metal shielding plate 123 is added to keep the insulating holders 122 from being extruding out from the conductive board 120 when the plug 10 is mounted onto the daughter card and further improve shielding performance.
The conductive board 120 defines four slots 132 in the first face respectively receiving corresponding contact modules and three isolating walls 131 . Each of the first contacts 121 includes a deflectable contacting portion 140 received in the front housing 11 , a foot portion 141 extending out from the conductive board 120 , and an intermediate portion 142 connecting the contacting portion 140 and the foot portion 141 . Differential signals are transferred in the contact pair 121 in each slot 132 of the conductive board 120 .
The conductive board 120 is made from die casting metal or conductive plastic, or insulating piece plated with a metal plating. In a preferred embodiment, the conductive board 120 is made from thermoplastic with a high melt point above 300 degrees Celsius, and plated with metal plating such as Chromium, Copper, Tin and Gold. Comparing to the second region made of a material with a binder containing conductive fillers to provide shielding between signal conductors, which disclosed in U.S. Pat. No. 6,709,294 B1 by Cohen et al. on Mar. 23, 2004, the plated conductive board 120 in present invention more perfectly provides shielding between adjacent wafers 12 and decreases crosstalk between adjacent contact pairs 121 received in the same wafer 12 . Further more, the contact modules are inserted into the slots 132 of the conductive board 120 , so there is no need to insert-mold the first insulating holders 122 into the slots 132 of the conductive board 120 , which decreases potential risk of destroying the metal plating of the conductive board 120 .
Each of the first insulating protector 124 includes a base board 126 , a pair of side walls 161 , an intermediate wall 162 , and a pair of cavities 163 for receiving the contacting portions 140 of corresponding pair of first contacts 121 . The first insulating protectors 124 has front ends received in the front housing 11 and rear ends received in the conductive boards 120 . The cavities 163 of the insulating protectors 124 and the slots 132 open to a same side in the transverse direction. The contacting portion 140 is sheltered by the first insulating protector 124 such that the contacting portion 140 is deflectable only in the transverse direction away from the first shielding plate 123 towards the conductive board 120 .
The header 20 includes a conductive shroud 21 and a number of contact modules 22 arrayed in the conductive shroud 21 . The conductive shroud 21 is made from die casting metal or conductive plastic, or insulating piece plated with metal plating. In a preferred embodiment, the conductive shroud 21 is made from thermoplastic, and plated with metal plating such as Chromium, Copper, Tin and Gold. The shroud 21 includes a bottom wall 23 , two upwardly extending side walls 24 and a receiving space 25 defined therebetween for receiving a portion of the plug 10 . The bottom wall 23 defines an array of holes 26 each receiving one of the second contact modules 22 .
Each of the contact module 22 includes a pair of second contacts 220 , a second insulating holder 221 insert-molded with the pair of second contacts 220 , a second shielding plate 222 assembled to the second insulating holder 221 , and a second insulating protector 223 . The second insulating holder 221 and the second insulating protector 223 are used to fix the pair of second contacts 220 and keep them isolated from the second shield 222 .
Each of the second contacts 220 includes a deflectable contacting portion 230 inserted into corresponding holes 15 of the plug 10 , a foot portion 231 extending downwardly for mounting onto the backplane, and an intermediate portion 232 connecting the contacting portion 230 to the foot portion 231 . The intermediate portion 232 is embedded in the second insulating holder 221 and isolated from the conductive shroud 21 .
Each second insulating holder 221 of the header 20 defines two positioning holes 240 . The second shielding plate 222 including a planar board portion 250 , a pair of ground feet 251 , and a flexible contacting arm 252 punched from the board portion 250 and extending towards the ground feet 251 . The second insulating protector 223 forms a pair of positioning posts 260 interference fitting with the two position holes 240 of the second insulating holder 221 . The conductive shroud 21 is electrically connected to the second shielding plates 222 and further electrically connected to the backplane through the grounding feet 251 of the second shielding plates 222 .
It should be understandable that when the plug 10 is mated with the header 20 , the conductive boards 120 make electrical connection with the conductive shroud 21 , and the contacting portions 252 of the second shielding plates 222 contact the front housing 11 of the plug 10 . It should be also understandable that the signal routing path, which extends from the foot portions 231 of the second contacts 220 to the foot portions 141 of the first contacts 121 , is completed shielded in all direction perpendicular to the signal routing path. Furthermore, the filling degree of the insulating holders 122 in one of the slots 132 varies along the signal path in such manner that the pair of the first contacts 121 are fixed to the conductive board 120 by two or three parts 145 , 147 , 148 of the insulating holders 122 along part lengths of the signal path, and part 146 of the first contacts 121 along part lengths of the signal path is exposed to the air.
Referring to FIGS. 5 and 6 , an electrical connector assembly 2 according to a second embodiment of the present invention is shown. The electrical assembly 2 has a plug (not shown) and a header (not shown) similar to the electrical connector assembly 1 except contact wafers 32 of the plug and the contact modules 42 of the header. Each of the contact wafers 32 has a conductive board 320 , four pairs of third contacts 321 , four third insulating holders 322 , four third insulating protectors 360 , and a third shielding plate 323 . A first difference for the contact wafer 32 is that the shielding plate 323 has four flat tab portions 352 forwardly extending beyond a front edge of the conductive board 320 , and each of the tab portions 352 forming a flexible contacting arm 353 . A second difference for the contact wafer 32 is that the third insulating protectors 324 are disposed between the contacting portions 340 and the tab portions 352 , and the third contacts 321 have contacting portions 340 deflectable in the transverse direction towards the tab portions 352 of the third shielding plate 323 . Each of the fourth contact modules 42 has a fourth shielding plate 422 , a fourth insulating protector 423 , a pair of fourth contacts 420 , a fourth insulating holder 421 . The main difference for the contact module 42 is that the fourth shielding plate 422 has a board portion 450 , two side walls 451 to define a U-shaped receiving slot 452 therebetween, and two flexible contacting arms 453 in the two side walls 451 , and the fourth insulating protector 423 is secured in the U-shaped slot 452 to isolate contacting portions 430 of the fourth contacts 420 from the fourth shielding plate 422 .
Referring to FIGS. 7-11 , an electrical connector assembly 3 according to a third embodiment of present invention is shown. The electrical connector assembly 3 has a plug 50 and header 60 similar to the first embodiment. The plug 50 includes a number of contact modules 502 stacked in a transverse direction and five grounding belts 53 connecting the contact modules 502 . Each of the contact modules 502 comprises a conductive board 51 , four contact modules 52 each having a pair of fifth contacts 551 and a fifth insulating holder 550 insert-molded with the pair of contacts 551 , and four insulating protectors 54 . Each of the conductive boards 51 defines a first face with a plurality of slots 562 defined therein and an opposite second face with three slits 565 defined therein. The conductive board 51 has three inner walls 561 and three ribs 564 . Each of the inner walls 561 is located between every two adjacent slots and each of the ribs 564 protruding from one of the inner walls 561 . The contact modules 52 are received in respective slot 562 .
When the contact modules 502 are transversely stacked, the ribs 564 mate into corresponding slits 565 of an adjacent contact module 502 to make complete shielding between adjacent fifth contact pairs 551 , and the conductive boards 51 jointly define a mounting face 57 to be mounted onto a daughter card (not shown), and a front face 58 . The front face 58 forms a plurality of holes 580 therein to receive contacts 620 of the complimentary header 60 . Each of the holes 580 formed by one slot 562 of said conductive board 51 and an adjacent conductive board 51 .
Each of the fifth contacts 551 has a foot 553 , a deflectable contacting portion 552 and an intermediate portion 554 connecting the foot 553 and the contacting portion 551 . The contacting portions 552 and the intermediate portions 554 of each contact pair 551 are received in corresponding slot 562 , and the feet 553 extending perpendicularly from the mounting face 57 .
Each of the insulating protectors 54 is received in the holes 580 and between the contacting portions 552 of corresponding pairs of fifth contacts 551 and the bottom wall of corresponding slot 562 . The contacting portions 552 are deflectable in the transverse direction towards the bottom wall of corresponding slot 562 and front ends of the contacting portion 552 are sheltered by the insulating protector 54 . The main difference for the header 50 comparing the header 10 of the first embodiment is that there is no conductive housing 11 and no first shielding plate 123 .
Jointly referring to FIGS. 10 and 11 , similar to the first embodiment, the filling degree of the fifth insulating holders 550 in one of the slots 562 varies along the signal path in such manner that the pair of the first contacts 551 are fixed to the conductive board 51 by one of the fifth insulating holders 550 along part lengths of the signal path, and at least part of the first contacts 551 along part lengths of the path is exposed to the air. It is further shown that the part of insulating holder 52 near the contacting portion 552 defines a slot 558 to change the dielectric disposed around the fifth contact pair 551 , which make the impedance to the signal in the fifth contact pair 551 approaching a constant along the signal path.
Referring to FIGS. 7-9 , the header 60 includes a conductive shroud 61 , sixteen pairs of sixth contact modules 62 , four sixth shielding plates 68 , and five grounding belts 684 . Each of the sixth shielding plates 68 has four flat tabs 681 and four flexible contacting arms 682 . Each of the sixth contact modules 62 includes an insulating holder 621 and a pair of sixth contacts 620 . Each of the sixth contacts 620 has a non-deflectable contacting portion 630 . The conductive shroud 61 includes a bottom wall 63 , two upwardly extending side walls 64 and a receiving space 65 defined therebetween for receiving a portion of the plug 50 . The bottom wall 63 of the conductive housing 61 defines four through holes 66 each having pairs of ribs 663 protruding from opposite inner faces of the holes 66 , the pairs of ribs 663 dividing each of the holes 66 into four receiving spaces to receive one of the contact modules 62 and corresponding tab 681 of the shielding plates 68 .
The differences for the header 60 comparing to the first embodiment is listed as below: (1) there is no insulating protector between the tabs 681 of the shielding plates 68 and the contacting portions 630 , which improve the impedance of the contact pair; (2) each hole 66 of the shroud 61 receive four sixth contact modules 62 and corresponding flat tabs 681 stacked in a column direction; (3) four flat tabs 681 corresponding to each contact module 62 are integrally formed in the sixth shielding plate 68 extending in a row direction; (4) there are grounding belts 684 extending along the column direction and connecting the sixth shielding plate 68 and the conductive shroud 61 to the backplane.
Referring to FIGS. 12-13 , a connector assembly according to a fourth embodiment is shown. The connector assembly includes a plug 70 and a header 80 . The header 80 includes four contact wafers 820 and a guide wafer 840 stacked in a transverse direction, and two sawtooth organizers 830 latching opposite sides of the wafers 820 , 840 . Each of the contact wafers 820 includes a conductive board 822 and four contact modules 850 . Each of the contact modules 850 has similar structure to aforementioned contact module 42 . The plug 70 includes four contact wafers 71 and one guide wafer 740 stacked in a transverse direction, and three organizers 730 latching the wafers 71 , 740 . The metal shielding plate 720 is added to keep the contact module 716 from being extruding out from the conductive board 710 when the plug 70 is mounted onto the daughter card and further improve shielding performance.
Referring to FIGS. 14-15 , a connector assembly according to a fifth embodiment is shown. The connector assembly includes a plug 90 and a header 91 . The header 91 has similar structure to the aforementioned header 80 . The plug 90 has similar structure to the aforementioned plug 70 except that each contact wafer 920 adds two contacting plates 901 , 904 extending across four pairs of contacts 921 aside the contacting portions 922 to improve shielding performance and mating durability, wherein the contacting plate 901 is integral with a shielding plate 900 covering aside the contact wafer 920 .
Referring to FIG. 16 , a method for making the contact wafer 12 of the plug 10 is shown. The method includes the following steps: (1) punching a metal strip to form a contact pair 121 including a left contact 170 and a right contact 171 , the left contact 170 and the right contact 171 being carried in a planar in an edge-to-edge manner; (2) insert-molding the contact pair 121 into an insulating holder 122 with a left edge 173 of the left contact 170 and a right edge 175 of the right contact 171 embedded in the insulating holder 122 , and a right edge 174 of the left contact 170 and a left edge 176 of the right contact 171 exposed to air; (3) assembling the contact module formed in step (2) into a slot 132 of a conductive board 120 ; (4) covering a shielding plate 123 over a side of the conductive board 120 . Jointly referring to FIG. 3 , it could also be described that each pair of contacts 170 , 171 are kept in a planar surface with near edges 174 , 176 facing to each other and far edges 173 , 175 backing away from each other, the far edges 173 , 175 of the intermediate portions embedded in the first insulating holder 122 and the near edges 174 , 176 of the intermediate portions exposed to air in part length of the signal path, which make the pair of contacts 170 , 171 firmly fixed by the first insulating holders 122 , and at the same time there is void between the near edges 174 , 176 to improve the impedance of the contact pair 170 , 171 .
Referring to FIG. 17 , a second method for making the contact wafer 12 is shown. The method includes the following steps: (1) providing a conductive board 130 having slots 132 therein; (2) insert-molding a first plastic 180 on a bottom wall of the slot 132 ; (3) putting a contact pair 170 , 171 punched from a metal strip into the slot 132 and on the first plastic 180 , and insert-molding a second plastic 181 in the slot 132 on the first plastic 180 and the contact pair 170 , 171 ; (4) covering a shielding plate 123 over a side of the conductive board 120 .
Referring to FIG. 18 , a third method for making an alternative contact wafer 12 is shown. The method includes the following steps: (1) providing a conductive board 130 having through holes 132 therein; (2) insert-molding a contact pair 170 , 171 and an insulating holder 122 into the through holes 132 with near edges 174 , 176 exposed to air and far edges 173 , 175 embedded in the insulating holder 122 ; (3) covering two metal plate 123 over opposite sides of the conductive board 120 .
It is to be understood, however, that even though numerous, characteristics and advantages of the present invention have been set fourth in the foregoing description, together with details of the structure and function of the invention, the disclosed is illustrative only, and changes may be made in detail, especially in matters of number, shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
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An electrical connector ( 10; 20; 50; 60; 70; 80; 90; 91 ) includes a conductive body ( 11, 12; 21; 32; 502; 61; 71; 822; 920 ), and a plurality of contact modules mounted on the body, each of the contact modules comprising a plurality of contacts ( 121; 220; 321; 420; 551; 620; 921 ), a shielding member ( 123; 222; 323; 422; 53; 68; 720; 900 ) and an insulator ( 122; 221; 322; 421; 550; 621 ) for fixing the contacts. The conductive body electrically connects with the shielding member and is insulated with the contacts.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application for patent claims the benefit of U.S. Provisional Applications bearing Ser. Nos. 61/254,137 and 61/254,146, both filed on Oct. 22, 2009, which are incorporated by reference in their entirety.
BACKGROUND
[0002] 1. Field of the Invention
[0003] This invention relates to oil field production apparatus and techniques, and more particularly, to such apparatus and techniques for use in the production of heavy oil or viscous crude oil.
[0004] 2. Background of the Invention
[0005] It has been known to produce viscous crude oils in reservoirs by drilling vertical wells into the producing zone and then injecting steam into the producing zone to increase the mobility and reduce the viscosity of the viscous crude. This steam injection has been done in several different ways. In one technique, wells in the reservoir can be cyclically steamed using a process called cyclic steam stimulation (CSS). In this process, steam is injected down a vertical well into the producing zone. The steam is allowed to “soak” in the reservoir for a relatively short period of time to heat the crude oils, thus reducing its viscosity and increasing its mobility. The well is then placed back in production for a relatively longer period of time to extract the heated less viscous crude oil. This cycle is typically repeated until the production becomes unprofitable.
[0006] Another technique which has been used to produce viscous crude reservoirs is to drill vertical wells in a geometrical pattern into the producing zone, such as in a 5-spot or 9-spot pattern. In these geometrical patterns, the wells are placed within the reservoir field, typically in a symmetric fashion, and are designated as either an injection well or a production well based on its position in the pattern. Steam is continuously injected into the producing zone via the injection wells to heat the viscous crude oil and drive it to neighboring vertical producing wells in the geometrical array.
[0007] In the initial development of a reservoir of viscous crude these described methods have worked well. Over time however, the steam tends to congregate in the upper portion of the producing zone. This, of course, may cause less heating of the viscous crude in the lower portion of the producing zone. The heavy crude saturated lower portion of the producing zone is not depleted as the high viscosity of the crude prevents its migration to the well bores of the producing wells. Thus large quantities of potentially producible crude oil can otherwise become not recoverable.
[0008] It is known in the art that horizontally-oriented, or horizontal wells can be utilized to help production from the portions of the producing zone, especially the lower portion discussed above, which are typically not depleted after injecting steam with vertical wells. It is desirous in these assemblies to deliver uniformly distributed steam to the producing zone along the entire length of the horizontal section of the well.
[0009] Horizontal steam injection wells are becoming more functional and efficient for heavy oil steam flooding and in many cases the only economic solution to produce some reservoirs. Successful application of horizontal steam injection requires controlled steam distribution along the entire length of the horizontal section. Many devices have been promoted as completion methods to provide this controlled distribution; however, these devices have not been tested and have severe limitations.
[0010] The main limitation is that the proposed equipment can at best provide control for the injection of single phase steam (“100% quality”). The performance of such devices when extracting a portion of a wet steam flow, vapor and liquid, suffers from phase splitting effects. This phase splitting phenomenon relates to the fact that the percent of vapor extracted from the total vapor is different than the percent liquid extracted from the total liquid. For example, if the main flow has a steam quality of seventy-percent (70%), the extracted flow may have a significantly higher or lower quality.
[0011] Many steam flood operations use two-phase steam consisting of both a vapor and a liquid phase. Even for operations injecting single phase, 100% quality steam at the wellhead, heat losses and water holdup can yield varying steam qualities along the subsurface horizontal section. Furthermore, if both phases do not split proportionally within a device, mass distribution is non-uniform and uniform latent heat—a more crucial reservoir performance criteria—is not achieved.
[0012] Most proposed devices extract steam off the main tubing flow through a series of orifices which may or may not feed additional flow restricting mechanisms before delivery to the reservoir. The basis for many of these devices and hopes for success rely on modified Inflow Control Devices (“ICDs”) operating in a reversed flow direction (“injection mode”). Although not fully tested, such mechanisms do have potential for the distribution of single phase, 100% quality steam. However, in applications utilizing two-phase steam, flow regime effects and different phase velocities cause unknown phase distributions depending on the vapor-water separation within the device. Optimum steam distribution and latent heat delivery requires a device capable of reliably controlling injected steam over a range of qualities of about forty percent (40%) to one-hundred percent (100%).
SUMMARY
[0013] According to an aspect of the present invention, a well assembly is disclosed for injecting steam into a subterranean reservoir. The well assembly includes a string of tubing in fluid communication with a producing zone of a subterranean reservoir. The string of tubing has a substantially vertical section and a substantially horizontal section extending from a lower portion thereof. The substantially horizontal section defines a heel portion at one end and a toe portion at the opposite end. An opening formed on the inner surface of the substantially horizontal section defines an inlet. An opening formed on the outer surface of the substantially horizontal section defines an outlet. A passageway extends between the inlet and the outlet such that steam received by the inlet is delivered to the outlet. The inlet is formed in the string of tubing axially closer to the heel portion than the outlet so that when steam is received by the passageway an axial momentum of the steam is maintained. For example, the passageway can extend less than about fifteen degrees from the inner surface.
[0014] In one or more embodiments, the string of tubing has a reduced cross-sectional flow area and the inlet is formed in the reduced cross-sectional flow area. For example, the reduced cross-sectional flow area can have an inwardly tapered surface and the inlet can be formed at least partially on the inwardly tapered surface.
[0015] In one or more embodiments, the string of tubing has a reduced cross-sectional flow area having an inwardly tapered surface, an outwardly tapered surface, and a reduced diameter surface extending between the inwardly tapered surface and the outwardly tapered surface so that a velocity of the steam is increased by the inwardly tapered surface and the velocity of the steam is reduced by the outwardly tapered surface.
[0016] In one or more embodiments, an annulus that is in fluid communication with the outlet is formed in the outer surface of the string of tubing and extends around the circumference thereof. A nozzle can be positioned within the annulus to control the flow of steam received from the outlet.
[0017] Another aspect of the present invention includes a well assembly for injecting steam into a subterranean reservoir. The well assembly includes a string of tubing in fluid communication with a producing zone of a subterranean reservoir. The string of tubing has a substantially vertical section and a substantially horizontal section extending from a lower portion thereof. The substantially horizontal section defines a heel portion at one end and a toe portion at the opposite end. A reduced cross-sectional flow area is positioned between the heel portion and the toe portion of the substantially horizontal section. An opening formed on the inner surface of the reduced cross-sectional flow area defines an inlet. An opening formed on the outer surface of the substantially horizontal section defines an outlet. A passageway extends between the inlet and the outlet to deliver steam from the inlet to the outlet.
[0018] In one or more embodiments, the string of tubing has a reduced cross-sectional flow area having an inwardly tapered surface, an outwardly tapered surface, and a reduced diameter surface extending between the inwardly tapered surface and the outwardly tapered surface so that a velocity of the steam is increased by the inwardly tapered surface and the velocity of the steam is reduced by the outwardly tapered surface.
[0019] In one or more embodiments, the inlet is formed on the reduced diameter surface. For example, the inlet can be axially closer to the heel portion than the outlet so that when steam is received by the passageway an axial momentum of the steam is maintained. Alternatively, the inlet and the outlet can be formed at substantially the same axial locations between the heel portion and the toe portion.
[0020] In one or more embodiments, the inlet is formed at least partially on the inwardly tapered surface. For example, the inwardly tapered surface can be tapered about fifteen degrees from an axis of the substantially horizontal section and the inlet can be about parallel to the axis of the substantially horizontal section.
[0021] In one or more embodiments, an annulus that is in fluid communication with the outlet is formed in the outer surface of the string of tubing and extends around the circumference thereof. A nozzle can be positioned within the annulus to control the flow of steam received from the outlet.
[0022] Another aspect of the present invention includes a well assembly for injecting steam into a subterranean reservoir. The well assembly includes a string of tubing in fluid communication with a producing zone of a subterranean reservoir. The string of tubing has a substantially vertical section and a substantially horizontal section extending from a lower portion thereof. The substantially horizontal section defines a heel portion at one end and a toe portion at the opposite end. A reduced cross-sectional flow area having an inwardly tapered surface, an outwardly tapered surface, and a reduced diameter surface extending between the inwardly tapered surface and the outwardly tapered surface is positioned between the heel portion and the toe portion of the substantially horizontal section. An opening formed on the inner surface of the reduced cross-sectional flow area defines an inlet. An opening formed on the outer surface of the substantially horizontal section defines an outlet. A passageway extends between the inlet and the outlet such that steam received by the inlet is delivered to the outlet. The inlet is formed in the string of tubing axially closer to the heel portion than the outlet so that when steam is received by the passageway an axial momentum of the steam is maintained.
[0023] In one or more embodiments, the inlet is formed on the reduced diameter surface. For example, the passageway can extend less than about fifteen degrees from the inner surface of the reduced diameter surface.
[0024] In one or more embodiments, the inlet is formed at least partially on the inwardly tapered surface. For example, the inwardly tapered surface can be tapered about fifteen degrees from an axis of the substantially horizontal section and the inlet can be about parallel to the axis of the substantially horizontal section.
[0025] In one or more embodiments, an annulus that is in fluid communication with the outlet is formed in the outer surface of the string of tubing and extends around the circumference thereof. A nozzle can be positioned within the annulus to control the flow of steam received from the outlet.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIG. 1 is a schematic, sectional view of a prior art steam delivery in a horizontal well in the field of hydrocarbon production.
[0027] FIG. 2 is a schematic, sectional view of a prior art steam delivery in a horizontal well in the field of hydrocarbon production.
[0028] FIG. 3 is a schematic, sectional view of a prior art tubing string distribution assembly for use in a horizontal well in the field of hydrocarbon production.
[0029] FIG. 4 is a schematic, sectional view of a tubing string distribution assembly according to an embodiment of the present invention for use in a horizontal well in the field of hydrocarbon production.
[0030] FIG. 5 is a schematic, sectional view of a tubing string distribution assembly according to an embodiment of the present invention for use in a horizontal well in the field of hydrocarbon production.
[0031] FIG. 6 is a schematic, sectional view of a tubing string distribution assembly according to an embodiment of the present invention for use in a horizontal well in the field of hydrocarbon production.
[0032] FIG. 7 is a schematic, sectional view of a tubing string distribution assembly according to an embodiment of the present invention for use in a horizontal well in the field of hydrocarbon production.
[0033] FIG. 8 is a schematic, sectional view of a tubing string distribution assembly according to an embodiment of the present invention for use in a horizontal well in the field of hydrocarbon production.
[0034] FIG. 9 is a graph of steam phase splitting for a conventional tubing string distribution assembly for use in a horizontal well in the field of hydrocarbon production.
[0035] FIG. 10 is a graph of steam phase splitting for a tubing string distribution assembly according to an embodiment of the present invention for use in a horizontal well in the field of hydrocarbon production.
[0036] FIG. 11 is a graph of steam phase splitting for a tubing string distribution assembly according to an embodiment of the present invention for use in a horizontal well in the field of hydrocarbon production.
DETAILED DESCRIPTION
[0037] Referring initially to prior art FIG. 1 , a cross sectional view shows a wellbore 11 having vertical section 11 A and horizontal section 11 B. Wellbore 11 provides a flow path between the well surface and producing sand or reservoir 31 . Tubing string 13 and slotted liner 15 are also shown in FIG. 1 . The horizontal section 11 B of tubing string 13 includes a heel portion 13 A and an opposite toe portion 13 B. Slotted liner 15 is a completion device lining horizontal section 11 B of wellbore 11 and is typically isolated by a lead seal 17 from vertical section 11 A of wellbore 11 . Live steam is supplied via tubing string 13 and exits from toe portion 13 B at end 19 . The steam flow is as indicated by arrows 21 . Direct impingement of live steam onto slotted liner 15 at the area numbered 23 can potentially cause erosion and collapse of the liner 15 , which is an undesirable condition. Also, using this technique the steams' heat is concentrated near toe portion 13 B in areas 25 and 27 of reservoir 31 rather than along the length of slotted liner 15 .
[0038] Referring now to prior art FIG. 2 , wellbore 29 has vertical section 29 A, which goes to the surface, and horizontal section 29 B that penetrates a long horizontal section of producing sand or reservoir 31 . Slotted liner 37 lines horizontal section 29 B of wellbore 29 . Tubing string 33 is run in from the surface and, on the lower end thereof is plugged off by plug 35 . The horizontal section 29 B of tubing string 33 includes a heel portion 33 A and an opposite toe portion 33 B. The length of tubing string 33 , prior to the plug 35 , is provided with spaced apart drilled holes 39 along its entire horizontal section between heel portion 33 A and toe portion 33 B. Each drilled hole 39 is covered with a sacrificial impingement strap 41 . Sacrificial impingement straps 41 are constructed of a carbon steel material and may be ceramic coated if desired. Sacrificial impingement straps 41 are welded to tubing string 33 with an offset above each drilled hole 39 .
[0039] A steam generator source (not shown) is located at the surface and provides an input of steam into tubing string 33 . The steam travels down tubing string 33 to its lower horizontal section 29 B where it exits via drilled holes 39 . As will be described, while steam can exit tubing string 33 between heel portion 33 A and toe portion 33 B, uniform mass distribution and latent heat is not achieved along horizontal section 29 B.
[0040] Referring to FIG. 3 , a cross-section of a portion of tubing string 33 that is located within slotted liner 37 of FIG. 2 is shown. Sacrificial impingement straps 41 are not shown in FIG. 3 . Tubing string 33 includes inner surface 43 and outer surface 45 . A plurality of drilled holes 39 extend from inner surface 43 to outer surface 45 . Each drilled hole 39 extends radially outward, substantially perpendicular to inner surface 43 . Typically, drilled holes 39 are intermittently spaced between heel portion 33 A and toe portion 33 B of tubing string 33 for delivering steam to reservoir 31 . A two-phase fluid F, typically steam having vaporous water and liquid water droplets D, travel through tubing string 33 for delivery into oil sands or reservoir 31 .
[0041] When two-phase fluid F is under low velocity conditions, such as less than 40 feet per second, the flow is stratified. In particular, gravity causes the liquid phase to travel along the bottom portion of the pipe. When superficial vapor and liquid velocities are both low, the interface between the liquid and vapor phases is smooth. As vapor velocities begin to increase, the interface becomes wavy. As the superficial liquid velocities increase, the flow tends to form in slugs or large waves of liquid (short in duration) separated by stratified wavy flow. At very high superficial flow velocities, the liquid forms a ring on the inner surface of the pipe wall and the vapor travels in the center of the pipe. At high superficial vapor velocities and steam qualities, the liquid becomes entrained in the vapor core such that the pipe is filled with vapor except for small droplets of liquid mist.
[0042] Liquid droplets D have higher densities and thus higher momentum than the vaporous water, which restricts the ability of liquid droplets D to change direction. When liquid droplets D traveling in the main flow of fluid F encounter a smaller vapor flow, or velocity profile, toward drilled holes 39 , liquid droplets D experience a drag force to change direction. However, the momentum of liquid droplets D opposes this change of direction, thereby resulting in less movement toward drilled holes 39 . In the embodiment shown in FIG. 3 , the liquid droplets entrained in the vapor core must make sharp, radially outward turns with respect to the flow of fluid F for liquid droplets to enter drilled holes 39 for delivery into reservoir 31 . This results in the extracted steam having less liquid droplets D such that the quality of the steam delivered at the upstream portion of tubing string 33 is different from the steam delivered to the downstream portion of tubing string 33 . In particular, more liquid droplets will be delivered toward the downstream toe portion 33 A of tubing string 33 than to heel portion 33 B. Such a phenomenon is known as “phase splitting.”
[0043] In FIGS. 4-8 , alternative tubing configurations are provided to counteract the phase splitting described above so that more uniform quality steam is delivered to reservoir 31 from both the upstream and downstream portions of the respective tubing strings. More particularly, FIGS. 4-8 each show a portion of tubing sub or string of tubing 111 disposed between the heel portion and the toe portion of the horizontal section of a wellbore. As will be described, steam generated at the surface is delivered to tubing 111 for a more uniform steam quality distribution along the horizontal section of a wellbore into reservoir 31 .
[0044] Referring to FIG. 4 , tubing 111 includes a plurality of openings 117 extending from inner surface 113 to outer surface 115 . Openings 117 include an opening formed on inner surface 113 that defines inlet 117 A, an opening formed on outer surface 115 that defines outlet 117 B, and passageway 117 C extending between inlet 117 A and outlet 117 B such that steam received by inlet 117 A is delivered to outlet 117 B. Inlet 117 A is formed in the string of tubing axially closer to the heel portion than outlet 117 B. While openings 117 are illustrated as having about fifteen degree outward angles to the flow of fluid F, it should be understood that the optimum angle for openings 117 is the smallest angle allowed by machining tools.
[0045] A plurality of openings 117 are preferably intermittently spaced along the length of tubing 111 . For example, openings 117 can be positioned every 100 to 500 feet along tubing 111 . In general, spacing of openings 117 will be dependent upon the particular reservoir characteristics. One skilled in the art will appreciate that isolation between a first group of openings 117 and a second group of openings 117 can be utilized. Furthermore, conventional sand control mechanisms, such as a sand screen, can be placed adjacent to openings 117 . In one embodiment, tubing 111 ends near the heel portion and openings 117 are configured in the liner.
[0046] Openings 117 reduce the directional change necessary for liquid droplets to enter openings 117 , thereby making it easier for liquid droplets to exit tubing 111 . In particular, when steam is received by passageway 117 C an axial momentum of the steam is maintained. Accordingly, the difference in steam quality delivered from the upstream portion of tubing 111 compared with the downstream portion of tubing 111 is reduced as more liquid droplets entrained in the vapor core are able to exit openings 117 .
[0047] Referring to FIG. 5 , an alternative tubing configuration is provided to counteract the segregation of vapor and liquid in Fluid F so that more uniform quality steam is delivered to reservoir 31 from both the upstream and downstream portions of the respective tubing strings. As shown in FIG. 5 , tubing 111 includes mandrel portion or tubing sub 120 with a reduced cross-sectional flow area and a plurality of openings 117 extending from inner surface 113 to outer surface 115 . Openings 117 include an opening formed on inner surface 113 that defines inlet 117 A, an opening formed on outer surface 115 that defines outlet 117 B, and passageway 117 C extending between inlet 117 A and outlet 117 B such that steam received by inlet 117 A is delivered to outlet 117 B. Inlet 117 A and outlet 117 B are formed at substantially the same axial locations between the heel and the toe of the string of tubing. As with the embodiment in FIG. 4 , a plurality of openings 117 are preferably intermittently spaced along the length of tubing 111 , with each opening 117 being associated with a tubing sub 120 .
[0048] Tubing sub 120 includes inwardly tapered surface 121 that extends between the portion of inner surface 113 having the normal diameter of tubing 111 and reduced diameter surface 123 , which is where openings 117 are located. Inwardly tapered surface 121 is located upstream of openings 117 to condition the flow of fluid F. Tubing sub 120 can also include outwardly tapered surface 125 that is positioned downstream of openings 117 , and that extends from reduced diameter surface 123 to the portion of inner surface 113 having the normal diameter of tubing 111 .
[0049] The reduction in the diameter of tubing 111 at inwardly tapered surface 121 increases the velocity of fluid F, while the increase in diameter from outwardly tapered surface 125 reduces the velocity of fluid F. The continued variation of the velocity of fluid F along the length of tubing 111 induces mixing of liquid droplets D with the vaporous water prior to flowing toward openings 117 . Mixing fluid F can help provide a more uniform steam quality being delivered along the length of tubing 111 . By way of example, if tubing 111 were a conventional string of 4.5 inch tubing, inner diameter 113 would be about 3.96 inches. The desired velocity change could be achieved when reduced diameter surface 123 is equivalent to the inner diameter of standard 2⅜ inch tubing, which is about 2.44 inches. Preferably inwardly and outwardly tapered surfaces 121 , 125 are at about fifteen degree respective inclines or declines.
[0050] Referring to FIG. 6 , an alternative tubing configuration is shown where tubing 111 includes openings 117 extending at an angle from inner surface 113 to outer surface 115 . Openings 117 include an opening formed on inner surface 113 that defines inlet 117 A, an opening formed on outer surface 115 that defines outlet 117 B, and passageway 117 C extending between inlet 117 A and outlet 117 B such that steam received by inlet 117 A is delivered to outlet 117 B. Inlet 117 A is formed in the string of tubing axially closer to the heel portion than outlet 117 B.
[0051] In the embodiment, the diameter of inner surface 113 adjacent openings 117 is reduced, thereby making the thickness of tubing 111 immediately upstream and downstream of openings 117 thicker than in the embodiment shown in FIG. 4 . Similar to FIG. 5 , tubing sub 120 includes inwardly extending tapered surface 121 that extends between the portion of inner surface 113 having the normal diameter of tubing 111 and reduced diameter surface 123 , which is where openings 117 are located. Inwardly tapered surface 121 is located upstream of openings 117 to condition the flow of fluid F. Outwardly tapered surface 125 is positioned downstream of openings 117 and extends from reduced diameter surface 123 to the portion of inner surface 113 having the normal diameter of tubing 111 .
[0052] Tubing sub 120 in FIG. 7 is substantially the same as in FIGS. 5 and 6 except that openings 117 extend axially through tubing 111 from inwardly tapered surface 121 . Openings 117 include an opening formed on inner surface 113 that defines inlet 117 A, an opening formed on outer surface 115 that defines outlet 117 B, and passageway 117 C extending between inlet 117 A and outlet 117 B such that steam received by inlet 117 A is delivered to outlet 117 B. Inlet 117 A is formed in the string of tubing axially closer to the heel portion than outlet 117 B. Preferably, openings 117 are as close to parallel with the axial flow of fluid F as possible with machining capabilities. Locating openings 117 on inwardly tapered surface 121 allows liquid droplets to enter outlets 117 with minimal deviation from the path of liquid droplets D prior to encountering reduced diameter surface 123 . For example, the inwardly tapered surface 121 can be tapered about fifteen degrees from an axis of the tubing 111 and the inlet can be about parallel to the axis of the tubing 111 .
[0053] As shown in FIG. 7 , openings 117 extend axially to an annulus 129 formed radially outward of reduced diameter surface 123 . In particular, annulus 129 is formed in the outer surface 115 of the string of tubing and extends around the circumference thereof. However, in some embodiments annulus 129 is not present and openings 117 axially extend between inwardly tapered surface 121 and outer surface 115 .
[0054] The embodiment shown in FIG. 8 is substantially the same as FIG. 7 except that nozzles 131 are positioned in annulus 129 to receive fluid from openings 117 . Nozzles 131 can be sized to more precisely control the rate of steam delivery into reservoir 31 from each opening 117 along tubing 111 . Examples of nozzles 131 include an orifice with a reduced cross-section or a venturi. Additionally, because nozzles 131 are controlling the rate of steam delivery in this embodiment, openings 117 can be enlarged to enhance liquid droplet D capture to a predetermined amount.
[0055] The uniform steam delivery described with respect to the above embodiments can prevent steam migration into the underlying water zone or into the upper desaturated portion of the reservoir. Also by delivering the steam uniformly along the entire horizontal section of the producing zone penetrated by the horizontal section of the well, any potential damage to a production liner in this horizontal bore is reduced. Furthermore, the above embodiments reduce phase splitting along the horizontal section of the wellbore, thus delivering a uniform steam quality and ensuring uniform latent heat to the reservoir.
Example I
[0056] The performance of alternative tubing configurations can be illustrated through the use of a two-phase flow model. In particular, fluid typically flows as a film along the wall of the pipe and as droplets entrained in the vapor core. The liquid entrainment and film thickness in a flowing pipe can be determined using the two-phase flow model. Liquid entrainment can be estimated by the percent of the total liquid on the circumference of the pipe wall that is traveling at significantly lower velocity. At high superficial vapor velocities the liquid on the circumference of the pipe wall becomes entrained in the vapor core resulting in the pipe being filled with vapor and small liquid droplets D. Since gravitational effects in a horizontal section creates thicker films on the bottom, often the liquid thickness is also expressed in terms of a mean film thickness, which would represent the thickness of the film if evenly distributed over the entire inner circumference. In general, if more of the liquid is entrained in the vapor, a more representative sampling or extraction of two-phase flow will occur.
[0057] A two-phase flow model for 4.5 inch diameter tubing with a pressure of 400 psig, a mass flow rate of 1200 barrels of steam per day, and a steam quality of seventy percent (70%) was performed. The calculated liquid entrainment was twenty-six percent (26%), the mean liquid film thickness was 0.037 inches, and the bottom liquid film thickness was 0.14 inches. When the tubing is reduced to 3.5 inches and the other flow conditions are kept the same, the liquid entrainment is ninety-six percent (96%), the mean liquid film thickness is 0.003 inches, and the bottom liquid film thickness is 0.008 inches. The reduced cross-section increased the calculated entrained liquid from twenty-six percent (26%) to ninety-six percent (96%) and greatly reduced the liquid film to yield a more evenly and predictable extraction or distribution.
Example II
[0058] As will be described below, the performance of alternative tubing configurations are compared to prior art tubing string distribution assemblies using a surface horizontal steam injection facility. The horizontal steam injection facility is capable of testing a wide range of full-sized downhole completion equipment, such as tubing and liner flow control devices, at the surface under controlled conditions. Additional details of the surface horizontal steam injection facility can be found in S.P.E. paper #132410, titled, “Addressing Horizontal Steam Injection Completions Challenges with Chevron's Horizontal Steam Injection Test Facility.”
[0059] The steam quality extracted from the various tubing configurations was measured for all possible combinations of three inlet pressures, two inlet steam qualities, six inlet rates and two pressure extraction ratios. The figures below show the difference between the steam quality extracted through the device's exit and the steam quality flowing in the tubing as a function of the tubing superficial vapor velocity.
[0060] FIG. 9 shows steam quality results obtained using 4.5 inch tubing with four one-quarter inch holes drilled perpendicular from horizontal and phased 90 degrees around the circumference. This tubing device is similar to that shown in FIG. 3 , where liquid droplets must make a sharp 90 degree turn with respect to the flow of fluid for the liquid droplets to enter the holes for delivery into the reservoir. The range of steam quality differences between the entrance and extraction of the device has a large variation of −15 to +15 steam quality units.
[0061] FIG. 10 shows steam quality results obtained using a 4.5 inch tubing with four one-quarter inch holes drilled perpendicular from horizontal and phased 90 degrees around the circumference of a reduced 2″ internal diameter. Improvement in the steam quality difference can be observed with the holes positioned proximate to a reduced internal diameter compared to a device without a reduced cross-section (FIG. 9 )—particularly at velocities greater than 40 ft/sec where the steam quality difference is maintained within a smaller steam quality difference band (−10 to +5). As previously discussed, the reduced internal diameter varies the velocity of the steam along the length of tubing, thus inducing mixing of liquid droplets with the vaporous water prior to the steam exiting via the drilled holes.
[0062] FIG. 11 shows steam quality results obtained using 4.5 inch tubing with four one-quarter inch holes drilled at 15 degree angles from horizontal and phased 90 degrees around the circumference of a reduced 2″ internal diameter. The tubing configuration used to produce the results shown in FIG. 11 is substantially the same as the tubing configuration used to produce the results shown in FIG. 10 except that the drilled holes are now angled at 15 degrees from horizontal. The difference between the steam quality extracted through the angled holes and the steam quality flowing through the tubing is minimized for all tubing superficial vapor velocities. In particular, the steam quality over the entire velocity range yields a tighter steam quality difference band compared to the steam quality obtained using the four one-quarter inch holes drilled perpendicular from horizontal without a reduced internal diameter as shown in FIG. 9 .
[0063] While the invention has been shown in only some of its forms, it should be apparent to those skilled in the art that it is not so limited, but susceptible to various changes without departing from the scope of the invention. For example, tubing 111 for each of the embodiments shown in FIGS. 4-8 could be a tubing sub that is positioned between pairs of tubing rather than being integrated in the string of tubing itself
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Methods and apparatus for enhanced and improved viscous oil recovery are disclosed. A horizontal well is drilled through the viscous oil formation. A specially designed tubing string includes outlets that deliver steam more uniformly into the entire horizontal extent of the well borehole. Heat from the steam mobilizes and lowers the viscosity of the heavy crude wherein the crude is then produced to the surface via conventional lift arrangements.
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This application claims priority to U.S. Provisional Application Ser. No. 61/853,615, filed Apr. 9, 2013.
BACKGROUND OF INVENTION
1. Field of the Invention
This invention relates to jet drilling drain holes from well bores, primarily in oil and gas wells.
2. Description of Related Art
Oil and gas wells are usually drilled vertically and cased with steel pipe. Typical casing pipes are from 4.5 to 8 inches in diameter. In a typical short-radius jet drilling technique, a flexible tubing or hose attached to the bottom of small rigid tubing (work string) turns 90 degrees within a channel in a diverter attached to a larger (production) tubing inside the casing. Fluid is pumped through the work string, flexible tubing and a bit on the flexible tubing to drill drain holes that may extend 15 to 100 ft. or more from the casing into the rock formation. The drain holes allow more contact area with the rock formation, increasing the flow capacity of the well. Buckman (U.S. Pat. No. 6,668,948), Landers (U.S. Pat. No. 5,413,184) and others have developed short-radius drilling systems that have a radius of 4 inches or less, in which a jet bit (nozzle) and hose pass down through a tubing string in a vertical well to a diverter, which contains a path to deviate the jet bit and flexible hose to enable drilling deviated or horizontal laterals or drain holes in oil and gas wells.
There are limiting factors that can prevent a flexible hose from passing through a tight 90-degree turn in a 4-inch radius. Like coiled tubing, a flexible hose can sinusoidally, helically buckle, causing extra friction or drag. Reduction of friction between a flexible hose and surrounding pipe can allow more force to be applied at a bit. Excess friction may lead to “lockup.” When lockup occurs, no matter how much force is applied the tubing can no longer move. If excessive force is continually applied from above in a larger tubular (well tubing) having sufficient diameter, the work string and the flex hose can “pass by itself,” meaning that the flexible tubing turns enough to pass alongside the work string and inside the larger (production) tubing. In this condition, an observation at the surface of the work string rapidly going down the production tubing creates the illusion of jet drilling of the formation while the jet bit is not moving.
Another problem in conventional short-radius drilling is that a jet bit may “catch” inside threaded connections of jointed production tubing. If this occurs during the deployment of the jet bit and flex hose downhole, it has been observed that it is near impossible to complete the trip of the bit to the diverter.
A further problem is knowing when the jet bit is at the diverter and then in a position to be engaged at the formation. Without simple and precise knowledge of formation engagement one can falsely claim the drilling of a formation.
Method and apparatus are needed to eliminate the jet bit catching on tubing connections as it is inserted through the tubing down the well. A signal or indication at the surface is also needed when the jet bit encounters the diverter and the formation, and a technique to transmit greater axial force to the jet bit as it passes through the diverter and jet drills is needed.
BRIEF SUMMARY OF THE INVENTION
In one embodiment, a tubular system having an inner and outer pipe, the outer pipe enclosing an inner pipe and a flexible hose with a jet bit, is provided. The inner pipe is allowed to move freely a desired distance as the flexible hose and jet bit drill out into a formation. The tubular system also assures that the jet bit will not catch on the gaps in connections of the production tubing as the tubular system is placed in a well. A work string (coiled or jointed tubing) is used to place the tubular system in a well. A decrease in the work string weight at the surface will signal delivery of the outer tube to the diverter and then the jet bit can be lowered through the diverter. Because of a smaller-diameter confining tubular around the flexible hose, i.e., a “close-fitting tubular system,” the system assures minimum buckling of the flexible hose as the jet bit passes through the diverter and jet drills a lateral into a reservoir. Fluids may be used that are selected to reduce metal-to-metal frictional drag of the flexible tubing and other tubulars in the wellbore.
In another embodiment, a close-fitting tubular system is provided by installing a liner inside the production tubing before it is placed in a well with the diverter. In this embodiment, the bit is not enclosed as the flexible tubing and bit are placed in the well and the bit may catch in connections in the tubing. A soluble or degradable ball on the bit may be used to keep the bit from catching in the tubing gaps as it is being lowered. The close-fitting liner located above the diverter enables the hose to push the jet bit through the diverter and into the formation with significantly less buckling and frictional forces. The liner may be formed from a low-friction solid and fluids may be used that are selected to reduce metal-to-metal frictional drag of the flexible tubing and other tubulars in the wellbore.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
For a more complete understanding of the present invention and the advantages thereof, reference is now made to the following description taken in conjunction with the accompanying drawings in which like reference numbers indicate like features and wherein:
FIG. 1 illustrates a cased well and drilling apparatus provided herein for drilling through a casing and drilling a drainhole in a reservoir.
FIG. 2 illustrates the concept of helical buckling of a hose and a jet bit being caught within gaps inside production tubing.
FIG. 3A and 3B illustrate how a jet bit delivery system encloses a hose and jet bit and how it would travel as a jet bit and hose as a drainhole is drilled.
FIG. 4 illustrates fluid flow directed through a stinger and around the jet bit delivery system.
FIG. 5 illustrates an alternative design where a restriction (liner) is placed in the production tubing immediately above the diverter to provide a narrow path, which enables greater downward force transmission through a hose to a jet bit.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1 , one embodiment of drilling apparatus, such as disclosed in U.S. Pat. No. 6,668,948, which is hereby incorporated by reference for all purposes, is illustrated. Jet bit 20 has been used to jet drill lateral or drain hole 36 into formation 38 . Diverter 28 , attached to production tubing 26 , is used as a kickoff point for jet bit 20 to turn 90 degrees or a selected angle from vertical well 14 into formation 38 . Diverter 28 may turn the jet bit from 20 to 130 degrees within the diverting path. Well 14 typically will have steel casing 16 that has a surrounding layer of cement 18 to hold it in place. Jet bit 20 is connected to the distal end of flex hose 22 . Flex hose 22 may range in size from ¼-inch to 1-inch in outside diameter. Flex hose 22 is connected to the distal end of work string 24 at connector 23 , which is usually coiled tubing, as illustrated, but may be jointed tubing. Flow can be conveyed from pump 34 at surface to jet bit 20 downhole to perform jet drilling operations. Diverter 28 is placed on the lower end of production tubing 26 at the depth where drilling is to be conducted.
FIG. 2 shows how jet bit 20 can catch in production tubing 26 at coupler or collar 30 , where two sections (joints) of production tubing 26 come together. There can be as much as a 2-inch gap across coupler gap 32 where jet bit 20 could catch and turn. Once the distal end of hose 22 is stopped, hose 22 would then begin to buckle and create excessive drag between flex hose 22 and production tubing 26 . If the axial force is further increased on flex hose 22 the buckling would then become helical buckling and eventually lead to lockup. Lockup is defined when the drag force exceeds the axial force applied to the flex hose 22 . This can prevent the bottom hole assembly from reaching the diverter. Continuing to apply force can damage flex hose 22 .
The theory of buckling of coiled tubing in a well casing or hose within another tubular is well known. A specific example through testing by the inventors is given below. Whereas a stainless steel braid hose of 0.40 inch outside diameter, that is 20 feet in length, with an internal pressure of 8,000 psi is enclosed in a stainless steel tubular with an inner diameter of 1.12 inch. Table 1 has the axial forces exerted on the upper end on the pressurized hose and the axial force produced at the bottom of the pressurized hose across the 20 foot length.
TABLE 1
Upper Axial
Lower Axial
Force (LBS)
Force (LBS)
23
6.4
42
28
61
40.4
81
46
99
45
120
44.5
140
44.3
159
43.3
184
43.5
200
43
220
43
240
43
Note that with an upper axial force of 42 lbs. applied at the top yields a lower axial force of 28 lbs. at the bottom. Also, observe that once the applied upper axial force exceeds 99 lbs., the hose's buckling is such that lockup occurs in the tubular and no additional force is exerted at the lower end. Hence, if it takes a force above the buckling force for the jet bit and hose to pass through the diverter, the hose will just buckle and lock up in the tubing. A helically buckling segment will want to expand outwards adding to the frictional forces acting against the constraining outer tube, a normal force for the continuous length of the hose in contact. To decrease drag from buckling one can increase the hose bending stiffness and decrease radial clearance. Also, it is best that the inner surface of the pipe be smooth like stainless steel or other slick surfaces.
Further tests were conducted with different flex hoses that had varying diameters and bend-radius ratings. These variables all affect the buckling tendencies of flex hoses. Bend radius is one form of measurement of the flex hose's bending stiffness. Typically, in coiled tubing calculation a segment's bending stiffness is shown with the steel's Young's Modulus and the moment of inertia. Not being made of one continuous material, a flex hose's bending stiffness is hard to standardize, but for an example, a flex hose that has a 5-inch bend radius will have less tendency to buckle than a flex hose that has a 2.5 inch bend radius having the same diameter. The theory of buckling of tubing of hose within another tubular predicts that the normal force due to helical buckling is directly proportional to the radial clearance, r c and inversely proportional to bending stiffness, EI. Therefore, reducing the diameter of larger tubing around the flexible tubing, forming a “close-fitting” tubular system, can be used to decrease resistance to movement of the flexible tubing through the larger tubing.
A typical jet drilling setup would use 2⅜″ production tubing, with about a 2-inch inner diameter and a flex hose of a similar size in the previous example. Since the radial clearance would be greater, the helical buckling of the flex hose would be created at a significantly lower force than the 99 lbs. in the example for lockup to occur.
Referring to FIG. 3 , one embodiment of a close-fitting tubular system disclosed herein is shown. In FIG. 3A , outer pipe piece 42 encapsulates flex hose 22 , preventing the catching of the hose in sharp transitions (not shown) in production tubing 26 . At the distal end of the outer pipe 42 perforated stinger 46 may be placed; this perforated stinger 46 is designed such that it engages with diverter 28 to give a smooth transition into the diverter path 29 . At the upper end of the outer pipe piece 42 is an outer pipe piece upper transition 50 Inner pipe piece 40 operates within outer pipe piece 42 . At the distal end of inner pipe piece 40 is flex hose or tubing 22 . The proximate end of inner pipe piece 40 is connected to the distal end of work string 24 ; this allows inner pipe piece 40 to convey pressure and flow from work string 24 to flex hose 22 . Inner pipe piece 40 has an inner pipe piece upper transition 48 and an inner pipe piece lower transition 44 . Inner pipe piece 40 is free to move downward until upper transition 48 reaches outer pipe piece upper transition 50 . Inner pipe piece 40 is free to move upward until inner pipe piece lower transition 44 reaches outer pipe piece upper transition 50 . Therefore, work string 24 is used to lower flexible tubing 22 and all other apparatus attached to work string 24 into a well.
During a jet drilling operation, during placement of the apparatus in a well, the close fitting tubular system illustrated in FIG. 3A will keep flex hose 22 contained until stinger 46 engages the top of diverter path 29 . Weight may be added to outer pipe piece 42 such that when it engages diverter 28 it can be more easily observed on a weight indicator at surface when the pipe piece contacts the diverter and there is a decrease in the string weight. This confirms the location of the bottom-hole assembly. Then pressure and flow can be applied to work string 24 , which would then be conveyed through inner pipe piece 40 and flex hose 22 to jet bit 20 for jet drilling. Inner pipe piece 40 and flex hose 22 will then continue to move within stationary outer pipe piece 42 until inner pipe piece upper transition 48 reaches outer pipe piece upper transition 50 .
Illustrated in FIG. 3B , jet bit 20 has exited diverter 28 and drilled out into a rock formation, creating a lateral or drain hole. The length of the lateral will be limited by the travel of inner pipe piece 40 , restricted by the inner pipe piece upper transition 48 and the outer pipe piece upper transition 50 and the length of flex hose 22 . Outside pipe piece 42 remains stationary above the diverter while flexible hose 22 with bit 20 and inside pipe piece 40 move downward and jet drill a lateral.
Force can be transmitted from work string 24 through inner pipe piece 40 and flex hose 22 to overcome friction forces in diverter path 29 . Because of the smaller ID of outer pipe piece 42 than that of production tubing 26 , the radial clearance of flex hose 22 is less and therefore less drag will occur in outer pipe piece 42 than in previous tubing configurations. The surface of outer pipe piece 42 , of flexible hose 22 and of diverter path 29 may be formed from a low-friction material, which may be a solid liner or a coating applied to the surface. One low-friction material is TEFLON.
In FIG. 4 , fluid flow is illustrated by arrows through perforated stinger 46 and continuing up production tubing 26 . Fluid containing rock cuttings from jetting has been known to circulate up and through diverter path 29 into production tubing 26 . The perforations in perforated stinger 46 allow this natural flow path to continue and also restricts fluid from flowing up into outer pipe piece 42 and inner pipe piece lower transition 44 .
In FIG. 5 , another embodiment of a close-fitting tubular system restricting the buckling of flex hose 22 to allow greater force transfer by utilizing a tubing liner or smaller ID tubular 52 (hereinafter referred to as a liner) is illustrated. This enables greater force from work string 24 to be transferred through smaller pipe piece 40 to flex hose 22 and jet bit 20 to jet drill the lateral using diverter 28 attached to production tubing 26 . Smaller pipe piece 40 with transitions 44 and 48 may be omitted and work string 24 may be attached directly to flexible hose 22 if the diameter of work string 24 is small enough to pass through liner 52 . Tubing liner or smaller ID tubing 52 preferably has an internal diameter less than 1 inch greater than the external diameter of flexible hose 22 . “Soluble ball” 54 can be placed on the end of a jet bit 20 before the bit and flex hose 22 are lowered down the tubing. Ball 54 may be made of a material that is slowly soluble in water or a polymer material that degrades in water. Jet bit 20 will not catch on tubing connections with the rounded front of ball 54 . Once jet bit 20 is to the diverter or before drilling commences, pressure may be applied to blast off ball 54 , which then dissolves or degrades.
While the preferred embodiments directed in this invention have been discussed herein, further modifications to the preferred embodiments will occur to those skilled in the art and such modifications are included in the scope of this invention. Although the present invention has been described with respect to specific details, it is not intended that such details should be regarded as limitations on the scope of the invention, except to the extent that they are included in the accompanying claims.
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Apparatus and method for drilling a drain hole from a well are provided. A flexible tubing used for conveying fluid to a jet bit is confined radially by a reduced-diameter tubing piece or a liner in production tubing near the diverter used to direct the flexible tubing. Concentric tubing pieces allow location of the bit in a well by measuring weight of a work string.
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FIELD OF THE INVENTION
The invention relates to a reverse flushing filter device, especially for domestic water installations, the said device having a main filter between the inlet and the outlet and an outlet aperture for substances filtered out, the said aperture being adapted to be closed by means of a discharge shut off device.
Prior Art
Filter devices of this kind are already known per se and are used in domestic water installations for the purpose of filtering the water supplied through the mains, thus separating out particles of dirt.
In the course of time, the filter becomes increasingly obstructed and the resulting increase in flow resistance produces a pressure drop in the domestic water line. For this reason, the flow of water is periodically passed through the filter in the opposite direction by means of a change-over mechanism. As a result of this, the outside of the filter becomes, as it were, the inside of the filter, and this reverse flushing procedure releases the build up of dirt and the like from the filter. The water containing this dirt is discharged through the closable outlet aperture which is previously opened for the purpose. After the filter has been cleaned, the outlet aperture is closed again and the water again flows through the filter in the usual direction. The said reverse flushing filter device may also be used for other purpose, for example in hydraulic circuits.
When these known filter devices are used, no water or liquid can be supplied to the consumer unit while the reverse flushing procedure is in operation, the reason for this being that when the change over is made to reverse flushing, the outlet from the filter device is simultaneously shut off. In many cases, however, it is undesirable to shut off the supply of water or the like.
Another known reverse flushing filter device does allow the supply of filtered water to be maintained during the reverse flushing procedure, but this is achieved only with considerable complexity. In this case the device uses two screens through which the water normally flows simultaneously. As a result of the symmetrical arrangement of these two screens, they become contaminated simultaneously and substantially to the same extent. During reverse flushing one of the screens is cleaned first and, as soon as this one is clean, the other one is cleaned. In the event of heavy contamination of both screens, reverse flushing may no longer be possible, in which case the device must be dismantled. In this device, each filter screen requires an outlet valve, a shut off valve and a supply valve, the latter being located in front of each filter screen. This configuration requires a considerable structural length which not only increases production costs, but is also a disadvantage from the point of view of installation.
SUMMARY OF THE INVENTION
It is, therefore, the purpose of the invention to design a reverse flushing filter device, which will make filtered water available during the reverse flushing procedure, in such a manner that the reverse flushing device cannot automatically become clogged, and the reverse flushing mechanism is simple, rugged and compact.
It is proposed to achieve this purpose by means of a reverse flushing filter device described hereunder. For the sake of simplicity, only "water" will be mentioned hereinafter, although, as already indicated, this filter device may also be used to filter other media, for example oil and the like.
When the device is in normal operation, no water flows through the closable reverse flushing filter located upstream of the main filter. Instead, the water bypasses this filter, finally reaching the outlet through the main filter. Now if the reverse flushing filter shut off mechanism is opened, the water can also flow therethrough, since it will now reach the reverse flushing filter before it reaches the main filter. If, at the same time, access to the side of the filter which in normal operation serves as the supply side is shut off, and if the side of the filter acting as the outlet side during reverse flushing is hydraulically connected to the side of the main filter constituting the outlet side in normal operation, then the water flowing through the reverse flushing filter must inevitably flow through the main filter in the opposite direction. If, at the same time, the flow between the side of the filter constituting the outlet side during reverse flushing and the outlet from the filter device is shut off, then the contaminated water can emerge only through the discharge shut off element. The shut off element for the reverse flushing filter is designed and arranged in such a manner that a part of the water su-ply may be used for reverse flushing, while the remainder of the water bypasses the main filter and flows directly to the outlet from the filter device. This is a highly advantageous way of ensuring that, even during reverse flushing, only filtered water emerges from the filter device. As for the two flows of water mentioned above, the amount of each depends upon the pressure relationship. This arrangement not only ensures an uninterrupted flow of water through the filter device even during reverse flushing, but also a constant supply of filtered water. The use of a main filter, and of a reverse flushing filter through which no water flows during normal operation of the filter device, prevents the reverse flushing device from becoming blocked in the event of heavy contamination. During normal operation, almost no dirt is deposited upon the reverse flushing filter, since the incoming water does not flow through it. Instead, the said water merely flows past the outside of the said reverse flushing filter, and this flow keeps this side of the said filter constantly clean. Moreover, the device according to the invention does not require as many shut off elements as the last of the known filter devices mentioned above. Finally, but not least, the arrangement according to the invention provides a particularly simple and compact design.
According to one specially preferred example of embodiment of the invention, both the reverse flushing filter and the main filter are of tubular configuration, and the water flows therethrough only at right angles to their longitudinal axes. Since the reverse flushing filter shut off device is located in the interior thereof, the design is not only extremely compact but is also technically simple.
According to another development of the invention, it is proposed that the reverse flushing filter shut off device shall have a tubular shut off housing arranged concentrically with the reverse flushing filter and having at least one passage passing through the wall of the tube, the said passage being adapted to be closed off by means of a slide valve located in the interior of the tube. It is desirable, however, to provide not only one but a plurality of passages distributed uniformly around a plurality of circles.
The said slide valve is preferably tubular and has the same number of preferably radial passages, arranged in the same way, as the housing of the reverse flushing shut off device. In this connection, the arrangement and dimensions of the said passages or bores must be such that the webs of the slide valve between the said passages can cover the relevant passages in the shut off housing when the filter device is in normal operation, whereas during reverse flushing, the passages or bores in the shut off housing and the slide valves are in alignment. All of the bores are preferably of the same size. The gap between the slide valve and the housing enclosing it should provide the usual amount of play found in shut off slide valves. Any leakage may be prevented in the usual manner, with seals for example, but these must not interfere with the movement of the valve, the latter being preferably axially displaceable and secured against rotation. The use of a sliding valve instead of a rotating valve has certain technical advantages which will be dealt with hereinafter.
According to still another configuration of the invention, the slide valve is connected to, or made integral with, a shut off element which, in conjunction with a valve seat in the housing of the filter device, forms a shut off element for the incoming medium, the said shut off element being used to shut off the supply of medium to the side of the filter constituting the inlet side of the main filter under normal operating conditions. This shut off element has already been mentioned above and is open during normal operation. It is closed only during reverse flushing, in order to prevent contaminated water from entering the outlet from the filter device. Located in front of the discharge shut off element for the contaminated reverse flushing water is a throttling element, preferably a throttle disc valve, forming an annular throttling gap with the inner wall, or an inner shoulder, of the housing of the filter device. This throttling gap prevents a large flow of contaminated water through the discharge shut off element. According to a further development of the invention, the throttle disc valve is connected to the slide valve of the reverse flushing filter shut off device by means of a supporting member passing through the main filter longitudinally. The said throttle disc valve may also be moulded to the said supporting member, in which case they are positively connected. Since the shut off element for the valve which is closed during reverse flushing is also secured or moulded to the slide valve, the said parts together make up a single moving system. This makes it possible for the said throttle disc valve to perform an additional function which will be explained hereinafter. Since the volume of contaminated water flowing out depends upon the setting of the throttle disc valve, there is a drop in pressure downstream thereof. As a result of this, a displacing force acts upon the displaceable unit during reverse flushing, and this causes the shut off element of the shut off valve, closed during reverse flushing, to move to the closed position. Thus all that is required to close the normally open valve and to open the shut off element for the reverse flushing filter is to open the discharge shut off element.
According to still another configuration of the invention, the supporting member is tubular, the wall of the said tube having at least one passage, but preferably a plurality of rows of passages arranged one above the other. It is therefore desirable, mainly for production reasons, for the supporting member and the slide valve of the reverse flushing filter shut off device to consist of a common tube which is closed off, at the end facing the discharge shut off element, by the throttle disc valve. In order to eliminate manual return of the unit automatically displaced when the discharge shut off element is opened, and to provide an automatic return instead, it is proposed, according to another configuration of the invention, that the said common tube be adpated to be closed off, against the force of a return spring, in the direction of closing of the valve shut off element for the incoming medium. During reverse flushing, this spring is loaded or additionally loaded. However, as soon as the discharge shut off element is closed again, full pressure can build up again between the throttle disc valve and the discharge aperture. This enables the return spring to return the system displaced during reverse flushing to its starting position. The return spring may very advantageously be in the form of a compression spring, preferably a helical compression spring, inserted between the throttle disc valve and a step or the bottom of the housing of the filter device. In order to prevent the contaminated water from flowing freely away, the end of the helical compression spring remote from the throttle disc valve preferably rests upon ribs, projections or the like in the interior of the housing of the filter device. This provides outlet passages of sufficient width under the end of the said spring.
According to one specially preferred example of embodiment of the invention, the shut off element connected to the reverse flushing filter shut off element is provided, at the end associated with the relevant valve seat, with a throttle cone or the like co-operating with a throttle passage, throttle edge, or the like in the housing; moreover, the disc associated with the discharge shut off element is in the form of a piston displaceable with little play in a cylinder, the said piston entering an expanded cylinder bore as the throttling effect of the said shut off element increases, and emerging completely from the smaller bore of the cylinder when the shut off element is closed. To be more precise, when the upstream valve is in the closed position, the piston has emerged so far from the smaller cylinder chamber that the throttling action is completely or largely eliminated. In this variant there are really two consecutive throttling locations, the first of which becomes constantly smaller during the reverse flushing, while the latter expands progressively until its throttling action disappears. This design also provides automatic control of the system during the opening and closing of the discharge shut off element.
DESCRIPTION OF THE DRAWINGS
Various examples of embodiment of the invention are illustrated in the drawings attached hereto, wherein:
FIG. 1 is a vertical section through the longitudinal centre line of a first example of embodiment in normal operation;
FIG. 2 shows the same filter device during reverse flushing;
FIG. 3 is a vertical section through the longitudinal centre line of a second example of embodiment in normal operation;
FIG. 4 shows the same variant in the reverse flushing position;
FIG. 5 shows an intermediate position;
FIGS. 6 and 7 are vertical sections through two other examples of embodiment.
DESCRIPTION OF PREFERRED EMBODIMENTS
Housing 1 of the reverse flushing filter device according to the invention consists of a substantially pot-shaped lower part 2 and of an upper part 4 secured thereto with an interposed sealing ring 3. Lower part 2 of the housing is preferably made of transparent or translucent synthetic material. The upper part of the housing contains an inlet 5 and an outlet 6 in the form of moulded-on pieces of tube, the incoming line being screwed to the one and the ongoing line to the other. The connection may, of course, also be made by means of flanges or other known connecting means. Screwed into a thread in base 7 of lower part 2 of the housing is a discharge shut off element 8 in the form of a plug 10 adapted t be rotated in the direction of double arrow 9. The open position of the discharge shut off element for the contaminated medium, more particularly water, emerging during reverse flushing is shown in FIG. 1, while FIG. 2 shows the closed position. Both the main filter 11 and the reverse flushing filter 12 are of a circular tubular configuration. The medium can pass through both of these filters only radially. The said filters are of known design, consisting of wire gauze, for example. At least parts of the cylinder ends are closed off by discs or annular discs, the significance of which will be explained hereinafter.
The medium, hereinafter referred to only as water, enters housing 1 of the filter device in the direction of arrow 13. Since the reverse flushing filter contains a shut off device 14, which is closed when the filter device according to the invention is in normal operation, the water can flow only through main filter 11 to outlet 6. Shut off device 14 has a tubular housing 15 arranged concentrically with the reverse flushing filter, which can be screwed into the upper part of the housing by means of a thread 16, for example. Located externally of housing 15, and in spaced relationship to each other, are two annular discs 17, 18, between which reverse flushing filter 12 is inserted and sealed. Housing 15 has three rows of holes preferably spaced equally apart and distributed uniformly around the periphery of the said housing, the said holes forming passages 19, passing through the wall of the tube, for the water flowing through reverse flushing filter 12.
Located within shut off housing 15 is a tubular slide valve 20 also equipped with three rows of passages 21 or radial bores, the dimensions and arrangement thereof being comparable to those in shut off housing 15. Slide valve 20 is adapted to move up and down in the direction of double arrow 22, but it cannot rotate in housing 15. In the position shown in FIG. 1, the parts of the wall between passages 21 cover passages 19 in housing 15. For the sake of clarity, the play between shut off housing 15 and slide valve 20 is exaggerated. With the slide valve in the position shown in FIG. 1, therefore, no water can flow through passages 21. This becomes possible only if slide valve 20 is moved downwardly in the direction of arrow 23 (FIG. 2) for the purpose of aligning passages 19, 21 which, as shown in this figure, need not necessarily be of exactly the same size.
Slide valve 20 of shut off device 14 is connected to a shut off element 24 which, in the example of embodiment illustrated in FIG. 1, is in the form of a disc. The said valve and disc may also be moulded together. The force of return spring 25, the purpose of which will be explained hereinafter, causes the upper surface of shut off element 24 to bear against free end 46 of shut off housing 15 when the filter device is in its normal operating position. Shut off element 24 co-operates with a valve seat 26 which may be formed by an internal shoulder or a stepped constriction in housing 1. Valve seat 26 and shut off element 24 together form a shut off valve 27. Since this valve is normally held open by spring 25, it permits a constant flow of incoming water to the inlet or outside of main filter 11, except during reverse flushing.
Located in front of discharge shut off element 8 is a throttle element which, in the example of embodiment illustrated in FIG. 1, is in the form of a throttle disc valve 28, the outer contour of which forms, with inner wall 29 of the housing, an annular throttle gap 30. Throttle disc valve 28 is connected to slide valve 20 of shut off device 14 by means of a supporting member 31 passing centrally through main filter 11 in the longitudinal direction thereof. This supporting member is also in the form of a tube having a series of radial passages 32 arranged uniformly around circles spaced equidistantly apart. The diameter of this supporting member and that of the slide valve are preferably the same, so that both may be produced from a single length of tube. Secured sealingly to the lower end of the supporting member 31 is the said throttle disc valve 28. Main filter 11 is also sealed between throttle disc valve 28 and an annular disc 23 fitted to the upper end of the said supporting member.
The reverse flushing filter device described above operates as follows: with the displaceable system, displaceable in the direction of arrow 22, and to which, as already indicated, main filter 11 also pertains, in its starting position (FIG. 1), water entering in the direction of arrow 13 flows through shut off valve 27, main filter 11, passages 32 in supporting member 31, and mouth 34 of slide valve 20, to outlet 6. Any dirt or the like in the water is deposited upon the inlet or outside of main filter 11. No water flows through reverse flushing filter 12, since it is separated from outlet 6 by shut off device 14.
If discharge shut off element, or discharge plug 8 (FIG. 2) is now opened, a negative pressure is produced in housing chamber 35 below throttle disc valve 28 as a result of the effect of throttle gap 30. This reduces the forces acting in the direction opposite to that of arrow 23, and the displaceable system therefore moves in the direction of arrow 23. Shut off valve 27 is now closed, but shut off valve 14 inside reverse flushing filter 12 is simultaneously opened, and the incoming water can now no longer flow directly to main filter 11. It must flow instead through reverse flushing filter 12 and through the interior of shut off housing 15 and supporting member 31. From here it can flow radially outwardly, in a direction opposite to that in which it was previously flowing, through passages 32 to the inside of main filter 11 which constitutes the outlet side in normal operation. When the water flows radially from the inside to the outside, any particles deposited upon the outside of the filter are washed away. Since shut off valve 27 is closed, the contaminated water can flow only through throttle gap 30 to discharge shut off element 8, leaving the filter device through union 36 to which a line may be connected, if necessary. Dirt removal is improved by the conical configuration of the edge of throttle disc valve 28.
Since shut off device 14 is open during reverse flushing, the water flowing through reverse flushing filter 12, and therefore also filtered, can pass at least in part directly through discharge 6 to a consumer unit or units. In contrast to existing filter devices of this kind, the device according to the invention allows the consumer unit or units to be connected constantly to the water supply line, not shown.
As soon as discharge shut off element 8 is closed again, the pressure in housing chamber 35 increases, whereupon the displaceable system returns to the starting position shown in FIG. 1.
Thus in the design described above, the change-over is produced by flow resistance in the path of the water needed for reverse flushing. As shown in FIGS. 1 and 2 this flow resistance may be produced by an annular throttling location 30 or, if throttle disc valve 28 bears to a greater or lesser extent against the inner wall of housing 1, by means of one or more choke passages passing through the outer wall of disc valve 28. The cross section of the said throttling location must match the gap in shut off valve 27.
The second variant, shown in FIGS. 3 to 5, is substantially the same as the first variant described above. For this reason, only the differences will be described. Similar parts in the two variants bear the same reference numerals.
The end of shut off element 24 of shut off valve 27, pointing towards discharge shut off element 28, carries a throttle cone 37 fitted or moulted thereto. In the normal operating position, sealing edge 38 of throttling cone 37, which terminates in the form of a cylinder, is at a distance 40 from inner edge 39 of valve seat 26.
In the second example of embodiment, throttle disc valve 28 is in the form of a piston adapted to move in a cylindrical bore 41. This bore 41 may, for example, be the cylindrical inner wall of a cross sectionally rectangular inner bead 42 in housing 1 or lower part 2 of the housing. When main filter 11, and the whole mobile system, is moved downwardly in the direction of arrow 23 by the opening of discharge shut off element 8, then upper edge 43 of piston like disc 28 moves through cylindrical bore 41 and, simultaneously, throttling cone 37 enters the constricted portion of housing 1 located, in the direction of flow, after inner edge 39. This produces a throttling location and a pressure drop in the vicinity of valve seat 26. The said pressure drop causes main filter 11, and the mobile system, to move farther down in the direction of arrow 23, until shut off element 24 finally rests upon valve seat 26. At this time disc 28 emerges from constricted cylindrical bore 41 and enters expanded bore 42.
The method of operation of this second example of embodiment is substantially the same as that of the first variant. The only difference is that the throttle station, during reverse flushing, is in the vicinity of shut off valve 27. A certain amount of throttling, but of secondary importance only, takes place at disc 28, especially just as it is leaving constricted cylindrical bore 41 (FIG. 5). However, in the terminal position shown in FIG. 4, disc 28 is so far from bead 42 that there is no throttling of the flow at this location.
In the examples of embodiment illustrated in FIGS. 6 and 7, use is made of the same basic concept, but several details have been modified. Shut off housing 15 for shut off device 14 has only a single row of passages 19. Slide valve 20, which moves up and down in the interior of tubular shut off housing 15, in the direction of arrow 21, has no passages. Instead, it is moved, during reverse flushing, so far down in the direction of arrow 23 that its upper edge exposes at least partly, but preferably fully, passages 19. The seal between slide valve 20 and shut off housing 15 is in the form of a sealing ring 47 fitted in an external groove in the said slide valve, preferably an O-ring. Furthermore, upwardly pointing free end 48 of slide valve 20 bears against an inner step 49 on shut off housing 15. This inner step is both a sealing surface and a stop for the displaceable mechanism acted upon by spring 25. Sealing ring 47 bears against the inner wall of shut off housing 15. Moreover, free end 48 which, in the operative configuration of the device illustrated, lies above passages 19, is outwardly conical, in order to ensure a smoother opening of shut off device 14.
In the examples of embodiment illustrated in FIGS. 6 and 7, valve seat 26, which co-operates with shut off element 24, is separate and is sealed in the lower housing part 2, thus making it possible for the lower part of the housing to be of constant inside diameter. Throttle disc valve 28 does not co-operate directly with the inner wall of the housing, but with a ring 50 which is produced separately, is also sealed in, and is of a configuration which is hydraulically satisfactory.
Supporting member 31 is also of simpler design and has particularly large passages 32. It is produced in one place with throttle disc valve 28 and slide valve 20.
According to still another configuration of the invention, discharge shut off element 8 is in the form of a magnetic valve. This allows the reverse flushing procedure to be remote controlled and which makes the device independent of human error. In view of the fact that manually operated reverse flushing filter devices are rarely actuated, and that the resulting filter cake may infect the water, automatic reverse flushing acquires considerable significance.
In the example of embodiment illustrated in FIG. 7, use is made of the reverse flushing device according to FIG. 6, except that the upper part 4 of the housing is different. A pressure reducing valve 52 is fitted into an aperture 51 in the said modified upper part of the housing. Also moulded onto the upper part of the housing are connectors 53, 54 for measuring instruments, especially manometers and mano-thermometers, on both the inlet and outlet sides of the said housing, thus making it possible to determine pressure and/or temperatures at these locations. An integrad or separate high speed venting means may also be inserted into upper part 4 of the housing. The entire unit illustrated in FIG. 7 is frequently known as a so called "domestic water station". This shows that the reverse flushing filter device according to the invention may be used not only alone per se, but also in conjunction with other hydraulic mechanisms and devices, especially in so called integrated or compact designs.
In the examples of embodiment illustrated in FIGS. 6 and 7, the displaceable element moving up and down in the direction of double arrow 21 need not be secured against rotation. Neither is this absolutely necessary in the examples of embodiment illustrated in FIGS. 1 to 5. However, the dimensions of passages 19 and 21 must be such as to ensure that at least a portion of each passage 21 is in hydraulic communication with its associated passage 19 in any position of rotation of slide valve 20 in relation to shut off housing 15.
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A reverse flushing device has a housing with an inlet, an outlet and a first filter to receive the flow therebetween with means in the housing to divert flow through the first filter. A second filter, positioned upstream of the first filter, has an internal apertured housing with a movable apertured slide operable thereon to provide a closure to the second filter during flow through the first filter. The housing has a discharge aperture with a movable shut off element. The diverting means and tubular slide are responsive to opening of the shut off element whereby the former diverts flow through the first filter and the tubular slide aligns with the second filter housing to permit flow therethrough and into the tubular slide extension to reverse flush the particles on the first filter into the discharge aperture.
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BACKGROUND OF THE INVENTION
[0001] The subject matter disclosed herein relates to the art of component cooling and, more particularly to a cooling sleeve configured for in situ repair components requiring protection from localized heat.
[0002] Over time components wear, age, or become damaged and require repair. In situ repair is desirable, particularly for larger components or components that require significant disassembly to move. There exist several challenges with in situ repair including access to a repair site and a potential for damage to adjacent components. When the repair requires a heat generating process, heat damage to adjacent components is of high concern. Welding processes, for example, generate significant heat that may be conducted through the component requiring repair to adjacent components. Heat sensitive articles such as electronics, wiring, heat sensitive polymers, and the like could be damaged if exposed to heat levels associated with welding repairs. As such, welding is not appropriate for in situ repair when the adjacent components comprise or contain heat sensitive articles. Thus, when welding or another heat generating repair process is necessary adjacent to heat sensitive articles, in situ repair is not practical.
BRIEF DESCRIPTION OF THE INVENTION
[0003] According to one aspect of the exemplary embodiment a cooling sleeve includes a first end that extends to a second end, and at least one coolant inlet member. The cooling sleeve also includes a second sleeve portion. The second sleeve portion includes a first end section that extends to a second end section, and a coolant outlet member. The first and second ends of the first sleeve portion are operatively connected to corresponding ones of the first and second end sections of the second sleeve portion to form a continuous cooling zone. The coolant passing into the inlet member circulates through the cooling zone to create a localized temperature reduction.
[0004] According to another aspect of the exemplary embodiment, a method of cooling a component during an in situ heat intensive repair process includes positioning a first cooling sleeve portion about a portion of the component. The first cooling sleeve portion includes a coolant inlet member. A second cooling sleeve portion is positioned about another portion of the component. The second cooling sleeve portion includes a coolant outlet member. The first cooling sleeve portion is connected to the second cooling sleeve portion to form a cooling sleeve extending about the portion of the component. A flow of coolant is circulated into the coolant inlet member, about the component through a cooling zone defined by the cooling sleeve, and discharged from the cooling sleeve through an outlet member, a temperature of the component is lowered, and a high temperature repair process is initiated on the component adjacent the cooling sleeve.
[0005] According to yet another aspect of the exemplary embodiment, a generator rotor includes a plurality of winding sections. Each of the plurality of winding sections includes at least one conductor. A bearing land is positioned adjacent one of the plurality of winding sections, and a cooling sleeve is arranged about the one of the plurality of winding sections adjacent the bearing land. The cooling sleeve includes a first end that extends to a second end, and at least one coolant inlet member. The cooling sleeve also includes a second sleeve portion. The second sleeve portion includes a first end section that extends to a second end section, and a coolant outlet member. The first and second ends of the first sleeve portion are operatively connected to corresponding ones of the first and second end sections of the second sleeve portion to form a continuous cooling zone. The coolant passing into the inlet member circulates through the cooling zone to create a localized temperature reduction.
[0006] These and other advantages and features will become more apparent from the following description taken in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWING
[0007] The subject matter, which is regarded as the invention, is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
[0008] FIG. 1 is a perspective view of a component shown in the form of a generator rotor including a cooling sleeve in accordance with an exemplary embodiment;
[0009] FIG. 2 is an upper left perspective view of the cooling sleeve in accordance with an exemplary embodiment
[0010] FIG. 3 is a detail view of a seal member of the cooling sleeve of FIG. 4
[0011] FIG. 4 is a partial perspective view of the generator rotor of FIG. 1 illustrating the cooling sleeve being positioned about a portion of the generator rotor;
[0012] FIG. 5 is a partial perspective view of the generator rotor of FIG. 1 , illustrating first and second cooling guns connected to the cooling sleeve in accordance with the exemplary embodiment;
[0013] FIG. 6 is an upper right perspective view of a cooling sleeve in accordance with another aspect of the exemplary embodiment; and
[0014] FIG. 7 is a partial perspective view of a portion of the cooling sleeve of FIG. 6 .
[0015] The detailed description explains embodiments of the invention, together with advantages and features, by way of example with reference to the drawings.
DETAILED DESCRIPTION OF THE INVENTION
[0016] With reference to FIG. 1 , a generator rotor is indicated generally at 2 . Generator rotor 2 includes a rotor body 4 having a first end 6 that extends to a second end 7 . Generator rotor 2 includes a plurality of winding sections 9 - 11 that include conductors (not shown) which, when rotated in a magnetic field, generate an electrical current. Rotor body 4 also includes a number of bearing lands, one of which is indicated at 14 that rotatably support generator rotor 2 in a generator housing (also not shown). During operation, the bearing lands will occasionally wear. Conventionally, repair of a bearing land was a difficult if often times impossible process. If the repair required welding, exposure of the conductors in the winding sections to intense heat could cause additional damage. As such, often times, generator rotors would be replaced in their entirety when a bearing land required welding or another repair process that involved intense heat.
[0017] In the event that bearing land 14 requires welding, a cooling sleeve 20 constructed in accordance with the exemplary embodiment, is mounted to rotor body 4 . Cooling sleeve 20 is positioned between bearing land 14 and winding section 10 . As will become more fully evident below, cooling sleeve 20 provides localized cooling to rotor body 4 to protect conductors in winding section 10 from exposure to excessive heat generated during a welding or other heat intensive repair to bearing land 14 .
[0018] As best shown in FIGS. 2-4 , cooling sleeve 20 includes a first sleeve portion 30 and a second sleeve portion 32 . First sleeve portion 30 includes a first end 37 that extends to a second end 38 through an intermediate portion 40 . Intermediate portion 40 includes a first outer edge 42 and a second, opposing outer edge 43 . In the exemplary aspect shown, first outer edge 42 includes a seal member 46 . Seal member 46 is configured to abut rotor body 4 to substantially limit any escape of cooling fluid from cooling sleeve 20 . In order to further prevent leakage, seal member 20 may be provided with a cloth seal strip (not shown). First sleeve portion 30 is also shown to include a first flange member 48 positioned at first end 37 , and a second flange member 49 positioned at second end 38 . Each flange member 48 and 49 includes a mounting member, shown in the form of openings 50 and 51 respectively. Openings 50 and 51 receive fasteners (not shown) that secure first sleeve portion 30 to second sleeve portion 32 as will be discussed more fully below.
[0019] In further accordance with the exemplary aspect shown, second sleeve portion 32 includes a first end section 54 that extends to a second end section 55 through an intermediate section 57 . Intermediate section 57 includes a first outer edge section 59 and a second, opposing outer edge section 60 . In a manner similar to that described above, first outer edge section 59 includes a seal element 63 . In a manner also similar to that described above, second sleeve portion 32 includes a first flange element 66 provided at first end section 54 and a second flange element 67 provided at second end section 55 . Each flange element 66 , 67 includes a mounting element, such as opening 68 shown on flange element 67 in FIG. 4 . With this arrangement, fasteners (not shown) pass through opening 50 and an opening (not shown) on flange element 66 and opening 51 and opening 68 to join first sleeve portion 30 is joined to second sleeve portion 32 to establish a cooling zone 70 . More specifically, first sleeve portion 30 is positioned about a first portion (not separately labeled) of bearing land 14 and second sleeve portion 32 is positioned about a second portion (also not separately labeled) of bearing land 14 . Once in position, first flange member 48 is joined to first flange element 66 and second flange member 49 is joined to second flange element 67 with bearing land 14 extending though cooling zone 70 .
[0020] In still further accordance with the exemplary aspect shown, first sleeve member 30 include first and second coolant inlet members 74 and 75 that extend outward from intermediate portion 40 . Each coolant inlet member is fluidly connected to cooling zone 70 . Second sleeve portion 32 includes an outlet member 78 that extends outward from intermediate section 57 . Outlet member 78 includes an opening 80 that is exposed in cooling zone 70 . As will be discussed more fully below, a cooling fluid is introduced into each coolant inlet member 74 and 75 . The cooling fluid passes into cooling zone 70 and flows about bearing land 14 . The cooling fluid then exits from cooling zone 70 through outlet member 78 .
[0021] During a welding repair, cooling sleeve 20 is positioned about bearing land 14 as shown in FIG. 5 . Once in place, a first cooling gun 88 is fluidly connected to coolant inlet member 74 and a second cooling gun 89 is connected to coolant inlet member 75 . At this point, a cooling fluid, such as low temperature air or coolant is passed from each cooling gun 88 , 89 into cooling zone 70 . The cooling fluid circulates about bearing land 14 before exiting through outlet member 78 creating a localized low temperature zone at a portion of at bearing land 14 adjacent to winding section 10 . The localized low temperature zone allows a high temperature repair process to be carried out on bearing land 14 without damaging conductors in winding section 10 . At this point it should be understood that while the cooling fluid is described as low temperature air, other cooling fluids both gaseous and liquid could be employed.
[0022] At this point reference will be made to FIGS. 6 and 7 in describing a cooling sleeve 110 in accordance with another aspect of the exemplary embodiment. Cooling sleeve 110 includes a first sleeve portion 114 and a second sleeve portion 117 . First sleeve portion 114 includes a first end 121 that extends to a second end 122 through an intermediate portion 124 . First sleeve portion 114 includes an outer sleeve section 126 and an inner sleeve section 127 that collectively define a first coolant passage section 129 . Intermediate portion 124 includes a first outer edge 132 and a second outer edge 133 . First outer edge 132 is provided with a seal member 135 in a manner similar to that described above. First sleeve portion 114 is also shown to include a first flange member 138 positioned at first end 121 and a second flange member 139 positioned at second end 122 . Each flange member 138 , 139 includes a corresponding mounting member shown in the form of openings 141 and 142 respectively.
[0023] Similarly, second sleeve portion 117 includes a first end section 156 that extends to a second end section 157 through an intermediate section 159 . Second sleeve portion 117 includes an outer sleeve member 166 and an inner sleeve member 167 that collectively define a second coolant passage section 170 . Intermediate section 159 includes a first outer edge section 178 and an opposing second outer edge section 179 . In a manner similar to that described above, first outer edge section 178 includes a seal element 181 formed in a manner similar to that described above. Second flange portion 117 also includes a first flange element 184 positioned at first end section 156 and a second flange element 185 positioned at second end section 157 . In a manner also similar to that described above, each flange element 184 , 185 includes a corresponding mounting element such as shown in the form of openings 187 on flange 184 . With this arrangement, first sleeve portion 114 is joined to second sleeve portion 117 . Depending upon the diameter of bearing land 14 , a gap may exist between flange member 138 and flange element 184 , and flange member 139 and flange element 185 .
[0024] In further accordance with the exemplary aspect shown, first sleeve portion 114 includes a coolant inlet member 194 that extends outwardly from intermediate portion 124 . Coolant inlet member 194 is fluidly connected to first coolant passage sections 129 . Similarly, second sleeve portion 117 includes a coolant inlet member 195 that extends outwardly from intermediation section 159 and is fluidly connected to second coolant passage section 170 . In addition, coolant sleeve 110 includes a plurality of outlet members or openings 197 - 202 formed on inner sleeve member 167 . Although not shown, additional outlet members or openings are formed on inner sleeve section 127 . With this arrangement, a cooling fluid is introduced into coolant inlet member 194 . The cooling fluid passes into first and second coolant passage portions 129 and 170 and circulates about bearing land 14 before exiting from outlet members 197 - 202 into cooling zone 190 . In a manner similar to that described above, coolant sleeve 110 is positioned about rotor body 4 to provide localized cooling to protect conductors from excessive heat during, for example, a welding repair.
[0025] At this point it should be appreciated that while shown and described in connection with protecting a winding section of a generator rotor from excessive hear during a welding repair, the cooling sleeve in accordance with the exemplary embodiment, can be employed in a wide range of applications that require the establishment of a localized cooling zone. In addition, it should be appreciated that while shown as having a circular cross-section, the cooling sleeve in accordance with the exemplary embodiment can take on a variety of forms. Finally it should be appreciated that the temperature of the cooling fluid may vary depending upon specific application requirements.
[0026] While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.
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A cooling sleeve includes a first end that extends to a second end, and at least one coolant inlet member. The cooling sleeve also includes a second sleeve portion. The second sleeve portion includes a first end section that extends to a second end section, and a coolant outlet member. The first and second ends of the first sleeve portion are operatively connected to corresponding ones of the first and second end sections of the second sleeve portion to form a continuous cooling zone. The coolant passing into the inlet member circulates through the cooling zone to create a localized temperature reduction.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority from, and incorporates by reference the entire disclosure of, Japanese Patent Application No. 2012-169585, filed on Jul. 31, 2012.
FIELD
[0002] The present application relates to a hinge device which is used for opening and closing a housing of a display part with respect a housing of a keyboard part and to an electronic apparatus which uses the hinge device.
BACKGROUND
[0003] In a notebook PC or other such electronic apparatus which is provided with a keyboard part and a display part, the housing of the display part is connected to the housing of the keyboard part to be able to open and close by a hinge device. The hinge device is provided at a part forming the axis of opening/closing of the two housings (see Japanese Laid-Open Patent Publication No. 2011-58607 and Japanese Laid-Open Patent Publication No. 2008-250635). Further, when the electronic apparatus is not being used, the hinge device is used to close the display part and lay it flat over the keyboard part thereby enabling the electronic apparatus to be made more compact.
[0004] A hinge device in general is provided with a bracket which is attached to one housing and a pivot which is attached to the other housing and is designed so that the bracket holds the pivot in a rotatable manner. In an electronic apparatus which is provided with a keyboard part and a display part, the pivot can be made to turn with respect to the bracket so as to open or close the display part with respect to the keyboard part. This hinge device is a part which stands out in the appearance of an electronic apparatus, so a hinge cover is used to cover the hinge device and maintain a beautiful design and to prevent injury due to mistaken insertion of a finger into the hinge device. Various ideas are used to improve the method of installation of the cover for covering the hinge device.
[0005] Among these, there is the technique of arranging the pivot itself of the hinge device at the outside of a side surface of the far side of the housing of the keyboard part of the electronic apparatus to conceal the hinge device from the side which opens and closes the display part and thereby make the hinge device invisible to the user. In this regard, even if employing this technique, the hinge device is exposed at the outside of the side surface at the far side of the housing of the keyboard part of the electronic apparatus. For this reason, when the user puts his hand at the back side of the keyboard part of the electronic apparatus, he might mistakenly insert a finger in the hinge device. To prevent this, a hinge cover which covers the hinge device is necessary. On the other hand, in a structure which conceals the hinge device at the far side of the housing of the keyboard part of the electronic apparatus, the structure for connecting the display part to the hinge device becomes complicated and the hinge cover member also becomes complex.
[0006] In an electronic apparatus which employs a structure which conceals the hinge device from the side which opens and closes the display part, the hinge cover which conceals the pivot of the hinge device is provided at the far side of the housing of the keyboard part. Further, if adopting a structure in which the hinge cover is screwed to the housing of the keyboard part, the hinge cover will come off if the screws are removed. In such a structure, when performing maintenance on the display part, the screws are removed in the state with the display part closed, the display part is opened as it is, and the front cover of the display part is removed. When the display part finishes being maintained, the display part is attached to the keyboard part by assembly by the reverse procedure.
[0007] In this regard, when fastening a hinge cover by screws to the housing of the keyboard part of an electronic apparatus, the hinge cover is liable to fall off when opening and closing the apparatus. For this reason, even if possible to remove the hinge cover to detach the front cover of the display part, attaching the front cover to the display part and connecting the display part to the keyboard part become extremely difficult in terms of assembly process.
[0008] Therefore, it may be considered to fasten the hinge cover to the housing of the keyboard part of the electronic apparatus by a tab member which is provided at the hinge cover. However, when fastening a hinge cover by a tab member to a housing of a keyboard part of an electronic apparatus, there is the issue that the hinge cover will easily detach from the keyboard part when disassembling the front cover of the display part. Further, if fabricating the hinge cover so that the hinge cover does not mistakenly detach from the keyboard part during use of the electronic apparatus by the user, the structure of the hinge cover will end up becoming complicated.
SUMMARY
[0009] In one aspect, the present application has as its object to provide a hinge device which connects a keyboard part and a display part of an electronic apparatus, wherein a hinge cover will not be mistakenly detached at the time of use by a user and the hinge cover can be simply detached when detaching the front cover of the display part at the time of maintenance of the display part, and to provide an electronic apparatus which uses the hinge device.
[0010] According to one aspect, the present application provides a hinge device which is provided between a first housing and a second housing which is provided with a front cover of a display and which connects the second housing to the first housing to be able to open and close, wherein the hinge device is provided with a bracket which is provided with a first mounting part and a rotatable holding part of a pivot, the first mounting part being fastened to an end part of one of the housings, a hinge pivot member which is provided with a second mounting part and a pivot, the second mounting part being fastened to an end part of the other of the housings, the pivot being held by the rotatable holding part, and a hinge cover which is attached to the pivot of the hinge pivot member to be able to slide in its axial direction and which covers the pivot and the rotatable holding part of the bracket in a state where the pivot is held at the rotatable holding part, the hinge cover has an engagement tab which engages with the second housing to prevent the hinge cover from detaching from the pivot by the cover being slid after being attached to the pivot and a space part which opens in the direction of the second housing in the engaged state of the engagement tab, the front cover is provided with a projecting piece which is inserted into the space part if attached to the second housing when the engagement tab of the hinge cover is engaged, and the hinge cover is blocked from movement in the axial direction by the projecting piece in the state where the front cover is attached.
[0011] According to another aspect, the present application provides an electronic apparatus which uses a hinge device which is provided between a first housing and a second housing provided with a front cover of a display and which connects the second housing to the first housing to be able to be opened and closed.
BRIEF DESCRIPTION OF DRAWINGS
[0012] FIG. 1A is a perspective view which illustrates the appearance of an electronic apparatus which is provided with a keyboard part and a display part which are connected by a hinge device of the present application.
[0013] FIG. 1B is a perspective view which illustrates the appearance of an electronic apparatus which is provided with a conventional hinge device of the present application.
[0014] FIG. 2A is a perspective view which illustrates one example of a hinge unit which forms a hinge device of the present application.
[0015] FIG. 2B is a disassembled perspective view which illustrates an embodiment where the hinge unit which is illustrated in FIG. 2A is used to connect the display part and the keyboard part.
[0016] FIG. 3A is a perspective view of the electronic apparatus of FIG. 1A which is provided with the hinge device which is illustrated in FIG. 2A as seen from the bottom surface side.
[0017] FIG. 3B is an assembled perspective view of the partially enlarged view of part A of FIG. 3A plus a hinge cover which is used for the hinge device of the present application.
[0018] FIG. 4A is a partially enlarged perspective view which illustrates the same portion as FIG. 3B which illustrates the state of attachment of the hinge cover which is illustrated in FIG. 3B attached to the hinge device of the electronic apparatus.
[0019] FIG. 4B is a bottom surface view of an electronic apparatus in a state where hinge covers are attached to hinge devices as seen from the bottom surface.
[0020] FIG. 5A is a perspective view of a hinge cover which is used at the left side of the back surface of the electronic apparatus which is illustrated in FIG. 4B as seen from the front surface.
[0021] FIG. 5B is a perspective view of the hinge cover which is illustrated in FIG. 5A as seen from the back surface.
[0022] FIG. 5C is a perspective view of a hinge cover which is used at the right side of the back surface of the electronic apparatus which is illustrated in FIG. 4B as seen from the front surface.
[0023] FIG. 5D is a perspective view of the hinge cover which is illustrated in FIG. 5C as seen from the back surface.
[0024] FIG. 6 is a perspective view which illustrates the structure of one embodiment of a front cover which is used for the hinge device of the present application of the electronic apparatus which is illustrated in FIG. 1A .
[0025] FIG. 7A is a partially enlarged perspective view which illustrates a state of a stage before a hinge cover is attached to a hinge device which is attached to a display part of the electronic apparatus which is illustrated in FIG. 1A .
[0026] FIG. 7B is a partially enlarged perspective view which illustrates a state where the hinge cover which is illustrated in FIG. 7A is attached to the hinge device.
[0027] FIG. 7C is a schematic cross-sectional view which illustrates the connected state of the hinge cover and the housing of the display part along the line B-B of FIG. 7B .
[0028] FIG. 8A is a partially enlarged perspective view which illustrates the state where the hinge cover is made to slide along the pivot of the hinge device from the state of FIG. 7B so as to engage with the housing of the display part.
[0029] FIG. 8B is a schematic cross-sectional view which illustrates the connected state of the hinge cover and the housing of the display part along the line C-C of FIG. 8A .
[0030] FIG. 8C is a partially enlarged assembled perspective view which illustrates the process of attaching the front cover to the display part which is illustrated in FIG. 8B .
[0031] FIG. 9A is a partially enlarged perspective view which illustrates the state of attaching the front cover which is illustrated in FIG. 8C to the display part.
[0032] FIG. 9B is a schematic cross-sectional view which illustrates the connected state of the hinge cover and the housing of the display part along the line D-D of FIG. 9A .
[0033] FIG. 9C is a partially enlarged perspective view which illustrates the state of fastening a screw in a through hole of a projecting piece which projects from the front cover which is illustrated in FIG. 9A and FIG. 9B .
[0034] FIG. 9D is a schematic cross-sectional view which illustrates the connected state of the hinge cover and the housing of the display part along the line E-E of FIG. 9C .
[0035] FIG. 10A is a perspective view which illustrates the appearance of the display part alone of the present application to which hinge devices and the front cover are attached.
[0036] FIG. 10B is a partial cross-sectional view which illustrates the position of a hinge cover in an electronic apparatus which is provided with the hinge devices of the present application which are illustrated in FIGS. 4A and 4B .
DESCRIPTION OF EMBODIMENTS
[0037] Below, using the attached drawings, embodiments of the present application will be explained in detail based on specific examples.
[0038] FIG. 1A is a perspective view which illustrates the appearance of an electronic apparatus 10 which is provided with a hinge device 4 of the present application. The electronic apparatus 10 has a keyboard part 1 which is provided with input keys 5 and a display part 2 which is provided with a display. The display part 2 has a front cover 3 which protects the display attached to it. The display part 2 can be folded over the keyboard part 1 by the hinge device 4 . The hinge device 4 which is provided in the electronic apparatus 10 which is covered by the present application is at a position which is hidden from the user of the electronic apparatus 10 when opening and closing the display part 2 with respect to the keyboard part 1 .
[0039] As opposed to this, FIG. 1B is a perspective view which illustrates the appearance of an electronic apparatus 50 which is provided with a conventional hinge device 54 . The electronic apparatus 50 has a keyboard part 51 which is provided with input keys 55 and a display part 52 which is provided with a display. The display part 52 has a front cover 53 which protects the display attached to it. The display part 52 can be folded over the keyboard part 51 by the hinge device 54 . In the hinge device 54 which is provided at the electronic apparatus 50 , the pivot of the hinge device 54 is at the upper side of the keyboard part 51 , so the hinge device 54 is provided to be visible to the user of the electronic apparatus 50 .
[0040] FIG. 2A is a perspective view which illustrates one example of a hinge unit 4 U which is used as the hinge device 4 which is used in the electronic apparatus 10 . The hinge unit 4 U of this embodiment is provided with a bracket 20 which rotatably holds a pivot 33 and with a hinge pivot member 30 to which the pivot 33 is fastened. The bracket 20 is attached to the display part 2 , while the hinge pivot member 30 is attached to the keyboard part 1 . For this reason, the bracket 20 has two mounting parts 21 and 22 which are provided with mounting surfaces parallel to the pivot 33 and has rotatable holding parts 23 and 24 which are provided projecting from the mounting parts 21 and 22 and rotatably hold the pivot 33 .
[0041] Further, the hinge pivot member 30 has a pivot mounting part 36 which fastens the pivot 33 . This pivot mounting part 36 is provided at a front end part of an arm part 31 in a direction perpendicular to the arm part 31 . A base part of the arm part 31 is bent at right angles to the arm part 31 to form the mounting part 32 to the display part 2 . The mounting part 32 is provided with three through holes 34 for passing screws in this embodiment. The hinge unit 4 U which is illustrated in FIG. 2A , as illustrated in FIG. 2B , is attached to the display part 2 by the two mounting parts 21 and 22 .
[0042] On the other hand, the bottom surface 11 B of the housing 11 of the keyboard part 1 of the electronic apparatus 10 is provided with a boss part 13 for attachment of the hinge pivot member 30 . The top surface of the boss part 13 is provided with screw holes 14 to which screws may be fastened. The number of screw holes 14 is matched with the number of through holes 24 at the mounting part 32 of the bracket 20 . The arm part 31 of the bracket 20 is attached to the boss part 13 along the side surface of the boss part 13 . The mounting part 32 of the hinge pivot member 30 can be fastened to the boss part 13 by screwing a screw 6 which is passed through a through hole 34 to a screw hole 14 of the boss part 13 .
[0043] FIG. 3A is a perspective view of the electronic apparatus 10 which is illustrated in FIG. 1A which is provided with the hinge device 4 which was explained in FIGS. 2A and 2B as seen from the bottom surface, while FIG. 3B is an assembled perspective view including the partially enlarged view of part A of FIG. 3A plus a hinge cover 40 which is used for the hinge device 4 of the present application. As illustrated in FIG. 3A , the single electronic apparatus 10 is provided with hinge devices 4 at two locations. In the electronic apparatus 10 to which the present application is applied, as illustrated in this figure, the hinge devices 4 are provided at the back side of the keyboard part 1 at a lower side position of the display part 2 . Therefore, as illustrated in FIG. 1A , in the electronic apparatus 10 to which the present application is applied, the hinge devices 4 are not visible to the party operating the electronic apparatus 10 .
[0044] On the other hand, the hinge devices 4 which are provided with the brackets 20 and hinge pivot members 30 which are explained in FIGS. 2A and 2B are at positions which are not visible to the operator of the electronic apparatus 10 . However, the rotatable holding parts 22 of the brackets 20 and the pivots 33 of the hinge pivot members 30 of the hinge devices 4 are exposed at slots 15 of the housing 11 . Therefore, in the hinge devices 4 of the present application, as illustrated in FIG. 3B , hinge covers 40 are attached to the slots 15 to cover the rotatable holding parts 22 of the brackets 20 and the pivots 33 of the hinge pivot members 30 and prevent the user from mistakenly touching the rotatable holding parts 22 and pivots 33 . The configuration of the hinge covers 40 will be explained in detail later, but each hinge cover 40 has a blind plate 41 , a circular hole 42 , a pivot mounting plate 43 , an engagement tab 44 , a space 45 , and mounting plates 46 .
[0045] FIG. 4A is a partially enlarged perspective view which illustrates the state of attachment of a hinge cover 40 which is illustrated in FIG. 3B attached to a slot 15 of the housing 11 of the keyboard part 1 to conceal the hinge device 4 . In the state with the hinge cover 40 attached to the slot 15 , the hinge cover 40 does not slide inside the slot 15 . Further, as illustrated in FIG. 3A , the electronic apparatus 10 is provided with hinge devices 4 at two locations, so two hinge covers 40 which cover the hinge devices 4 are required.
[0046] FIG. 4B is a bottom surface view of an electronic apparatus 10 which illustrates a state where hinge covers 40 are attached to the hinge devices 4 at two locations of the back surface of the electronic apparatus 10 . The hinge covers 40 which are attached to two locations of the back surface of the electronic apparatus 10 are not the same but are symmetrical in shape to the left and right at the back surface of the electronic apparatus 10 . Here, the hinge cover 40 at the left side of the back surface of the electronic apparatus 10 is referred to as the “hinge cover 40 L”, while the hinge cover 40 at the right side is referred to as the “hinge cover 40 R”. The hinge covers 40 L and 40 R are attached by screws 6 to the back surface of the electronic apparatus 10 .
[0047] FIG. 5A is a perspective view of the hinge cover 40 L which is used at the left side of the back surface of the electronic apparatus 10 which is illustrated in FIG. 4B as seen from the front surface, while FIG. 5B is a perspective view of the hinge cover 40 L which is illustrated in FIG. 5A as seen from the back surface. Further, FIG. 5C is a perspective view of the hinge cover 40 R which is used at the right side of the back surface of the electronic apparatus 10 which is illustrated in FIG. 4B as seen from the front surface, while FIG. 5D is a perspective view of the hinge cover 40 R which is illustrated in FIG. 5C as seen from the back surface. The hinge covers 40 L and 40 R are just symmetric in shape to the left and right. They are configured exactly the same. Here, the hinge covers will be assigned the representative numbers “ 40 ” to explain their structures.
[0048] Each hinge cover 40 is provided with the blind plate 41 , the circular hole 42 which is provided at the blind plate 41 , the pivot mounting plate 43 , and the plurality of mounting plates 46 . The blind plate 41 is curved and covers the rotatable holding part 22 , pivot 33 , and slot 15 which are illustrated in FIG. 3B . Further, the pivot mounting plate 43 is attached to the pivot 33 , while the plurality of mounting plates 46 are inserted into the slot 15 . The pivot mounting plate 43 has a recessed part 43 a into which the pivot 33 is inserted, while the mounting plates 46 are shaped similar to the cross-sectional shape of the slot 15 in the direction vertical to the longitudinal direction.
[0049] Further, at the end part of the mounting plate 46 the furthest from the pivot mounting plate 43 , an engagement tab 44 is provided for engaging the hinge cover 40 with part of the housing 12 of the display part 2 to prevent it from detaching from the housing 12 of the display part 2 . Furthermore, the two mounting plates 46 at the center part of the hinge cover 40 are arranged at the two sides of the circular hole 42 at the blind plate 41 . Between these two mounting plates 46 , a space 45 of a predetermined distance is provided. Each hinge cover 40 is made of plastic and has a total length shorter than the length of the slot 15 in the longitudinal direction by exactly a length of at least the height of the engagement tab 44 from the mounting plates 46 .
[0050] FIG. 6 is a perspective view of the electronic apparatus 10 which is illustrated in FIG. 1A which illustrates extracted just the front cover 3 which protects the display at the display part 2 . The front cover 3 is provided with a transparent acrylic sheet or glass sheet at the inside of a frame 3 f. At the bottom end part of the frame 3 f, projecting pieces 7 are provided at two locations. The projecting pieces 7 are provided with through holes 8 which pass screws for attaching the front cover 3 to the display part 2 . Furthermore, the widths of the projecting pieces 7 are widths which enable insertion with substantially no clearance into the space 45 at the hinge covers 40 explained in FIG. 5A to 5D .
[0051] Above, FIGS. 1A and 1B to FIG. 6 were used to explain the configuration of the hinge device 4 of the electronic apparatus 10 and configuration of the hinge cover 40 which covers the hinge device 4 and, furthermore, the configuration of the front cover 3 which is attached to the display part 2 of the electronic apparatus 10 . Next, FIGS. 7A to 7C to FIGS. 10A and 10B will be used to explain the process of attaching the hinge cover 40 to a hinge device 4 which is already attached to the display part 2 and attaching the front cover 3 to the display part 2 so as to prevent the hinge cover 40 from detaching from the display part 2 .
[0052] FIG. 7A is a partially enlarged perspective view which illustrates the state of the stage before attaching a hinge cover 40 to a hinge device 4 which is attached to the display part 2 of the electronic apparatus 10 which is illustrated in FIG. 1A . In this state, the bracket 20 is already attached to the display part 2 . The pivot 33 of the hinge pivot member 30 is rotatably held by the rotatable holding parts 23 and 24 of the bracket 20 . Further, this state is the state where the hinge pivot member 30 is detached from the keyboard part of the electronic apparatus. The configuration of the hinge pivot member 30 has already been explained, so here only reference numerals will be attached to the members forming the hinge pivot member 30 and explanations will be omitted. Furthermore, reference numeral 9 which is illustrated in FIG. 7A is a screw hole which is provided at the housing 12 of the display part.
[0053] FIG. 7B is a partially enlarged perspective view which illustrates the state where the hinge cover 40 which is illustrated in FIG. 7A is attached to the hinge device 4 , while FIG. 7C is a schematic cross-sectional view which illustrates the connected state of the hinge cover 40 and the housing 12 of the display part along the line B-B of FIG. 7B . Note that, FIG. 7C illustrates only the positional relationship of the hinge cover 40 and the housing 12 of the display part. Illustration of the pivot 33 of the hinge device 4 is omitted. The hinge cover 40 is attached to the pivot 33 by the pivot mounting plate 43 which was explained in FIG. 5A to FIG. 5D . In this state, the screw hole 9 and the circular hole 32 of the hinge cover 40 are not centered with each other and the engagement tab 44 of the hinge cover 40 is not inserted in the engagement hole 12 H at the housing 12 of the display part.
[0054] FIG. 8A is a partially enlarged perspective view which illustrates the state of sliding the hinge cover 40 from the state of FIG. 7B along the pivot 33 of the hinge device 4 in the direction illustrated by the white arrow L to engage with the housing 12 of the display part. Further, FIG. 8B is a schematic cross-sectional view which illustrates the connected state of the hinge cover 40 and the housing 12 of the display part along the line C-C of FIG. 8A . FIG. 8B also illustrates only the positional relationship between the hinge cover 40 and the housing 12 of the display part. Illustration of the pivot 33 of the hinge device 4 is omitted. In this state, the screw hole 9 and the circular hole 32 of the hinge cover 40 are centered with each other and the engagement tab 44 of the hinge cover 40 is inserted in the engagement hole 12 H at the housing 12 of the display part. Therefore, in this state, the hinge cover 40 is engaged with the engagement hole 12 H at the housing 12 of the display part by the engagement tab 44 , so will not detach.
[0055] FIG. 8C is a partially enlarged assembled perspective view which illustrates the process of attachment of the front cover 3 to the display part 2 which is illustrated in FIG. 8B . The position of a projecting piece 7 which is provided at the frame of the front cover 3 matches the position of the space 45 at the hinge cover 40 after sliding which is illustrated in FIG. 8A . Therefore, if attaching the front cover 3 to the display part 2 , the projecting piece 7 is inserted into the space 45 of the hinge cover 40 .
[0056] FIG. 9A is a partially enlarged perspective view which illustrates the state where the front cover 3 which is illustrated in FIG. 8C is attached to the display part 2 , while FIG. 9B is a schematic cross-sectional view which illustrates the connected state of the hinge cover 40 and the housing 12 of the display part along the line D-D of FIG. 9A . As explained in FIG. 6 , the width of a projecting piece 7 is a width enabling insertion with substantially no clearance into the space 45 at the hinge cover 40 . Further, if the projecting piece 7 is inserted into the space 45 , as illustrated in FIG. 9B , the projecting piece 7 enters the space 45 with no clearance and the through hole 8 which is provided at the projecting piece 7 is aligned with the screw hole 9 which is provided at the housing 12 of the display part.
[0057] FIG. 9C is a partially enlarged perspective view which illustrates the state where a screw 6 is passed through the through hole 8 of a projecting piece 7 which is provided at the front cover 3 which is illustrated in FIGS. 9A and 9B and screwed to a screw hole 9 which is provided at the housing 12 of the display part. Further, FIG. 9D is a schematic cross-sectional view which illustrates the connected state of a hinge cover 40 and the housing 12 of the display part along the line E-E of FIG. 9C . The screw 6 may be engaged with the through hole 8 of the projecting piece 7 through the circular hole 42 of the hinge cover 40 and screwed with the screw hole 9 through the circular hole 42 by a screwdriver. In this state, the screw 6 is used to prevent the front cover 3 from detaching from the housing 12 of the display part. The hinge cover 40 does not move since the projecting piece 7 enters the space 45 with no clearance. Accordingly, the hinge cover 40 is held in a state connected to the housing 12 of the display part and will not detach from the housing 12 of the display part.
[0058] FIG. 10A is a perspective view which illustrates the appearance of the display part 2 , standing alone, which illustrates the state of the display part 2 to which the hinge devices 4 have been attached through the process of FIGS. 7A to 7C to FIGS. 9A to 9C to which, further, the hinge covers 40 and front cover 3 are attached. Further, FIG. 10B is a partial cross-sectional view which illustrates the position of a hinge cover 40 in the electronic apparatus 10 which is provided with the hinge devices 4 which are illustrated in FIGS. 4A and 4B . In this way, the display part 2 in the state with the hinge covers 40 being used to cover the hinge devices 4 can be detached from the keyboard part of the electronic apparatus. If attaching the display part 2 to the keyboard part, the hinge covers 40 are fit in the slots 15 which were explained in FIGS. 3A and 3B . Further, at the time of inspection of the display part 2 , if detaching the display part 2 from the keyboard part and inserting a screwdriver into the circular holes 42 to remove the screws, the front cover 3 can be detached.
[0059] With the structure of the hinge device explained above, it is possible to remove the keyboard cover by just detaching the screws in the hinge covers. When desiring to detach a hinge cover, it is possible to detach the hinge cover by just removing the screw and sliding off the hinge cover. As a result, it is possible to maintain the disassembly ability of the electronic apparatus while realizing prevention of detachment of the hinge covers etc. The reliability of the electronic apparatus also rises. Further, the hinge covers are easy to attach to and detach from the hinge devices and will not detach at the time of use by the user. Further, using such hinge devices, it is possible to realize an electronic apparatus which is provided with pivot structures which are easy to disassemble and assemble at minimal cost.
[0060] Note that, in the embodiments which are explained above, the projecting pieces 7 which are formed at the frame 3 f of the front cover 3 are provided with through holes 8 , and the front cover 3 is screwed to the screw holes 9 which are provided at the housing 12 of the display part by screws 6 which are inserted into the through holes. However, the front cover 3 can be attached to the housing 12 of the display part at other locations and the projecting pieces 7 which are formed at the frame 3 f of the front cover 3 can be given only the function of restricting movement of the hinge covers and the through holes 8 omitted. In this case, the front cover 3 may be provided with mounting pieces which are provided with mounting holes in addition to the projecting pieces 7 and screws which are passed through the mounting pieces may be used to screw them to the screw holes which are provided in the housing 12 of the display part 2 .
[0061] Furthermore, if changing the shapes of the mounting parts of the brackets of the hinge units and the mounting parts of the hinge pivot members, the brackets can be attached to the keyboard part side and the hinge pivot members can be attached to the display part side.
[0062] Although only some exemplary embodiments of this invention have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention.
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A hinge device which rotatably connects a display to a keyboard part comprised of a hinge pivot member which attaches the keyboard part and a bracket which is attached to the display and holds the hinge pivot member and of a hinge cover, wherein if making the bracket hold the hinge pivot member, then attaching the hinge cover to the pivot of the hinge pivot member and making it slide in the axial direction to engage it with the housing of the display part and attaching the front cover to the display part in this state, a projecting part which is provided at the front end part of the front cover is inserted in the hinge cover and return of the hinge cover in the axial direction is prevented, so the front cover and hinge cover can be simply removed at the time of maintenance of the display part.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application relates to co-pending U.S. patent application Ser. No. 09/949,068, filed on a date even herewith, entitled “Designing Integrated Circuits to Reduce Electromigration Effects” naming Hendrik T. Mau as inventor, which is assigned to the assignee of this application, the application being hereby incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to designing integrated circuits to increase reliability. More specifically, the present invention relates to designing integrated circuits to reduce failures due to electromigration.
2. Description of the Related Art
The reliability of recent very large scale integration (also referred to as “VLSI”) designs has been improved through better alloys, additional layers and increasing grain size. However, designers continue to have aggressively pursue increased product performance. Pursuing increased performance leads to higher clock speeds and power dissipation, which increase thermal density and thermal stress. High current densities and thermal stresses drive degradation mechanisms in the interconnect system of VLSI circuits. Specifically, high current densities lead to electromigration-caused failures.
Electromigration (also referred to as “EM”) is an atomic diffusion phenomenon and refers to the transport of ions or atoms due to the high current densities and/or strong electric fields. Electromigration is a temperature activated process. Therefore, temperature will influence the amount and speed of migration of ions and atoms. FIG. 1A illustrates the mechanics of electromigration. As shown in FIG. 1A, electric current leaves the metal strip at the anode and is conducted to the cathode. The electrical current causes metal particles to migrate from the cathode side of the strip to the anode side of the strip. By definition, the electrical current is in the opposite direction to the electron flow. Thus, metal particles deplete the cathode side of the metal strip and accumulate on the anode side. Depletion of the cathode side can cause voids which can cause an open circuit. Accumulation on the anode side can lead to a hillock which can cause a short circuit. Thus, both accumulation and depletion can cause failure of a microprocessor or other integrated circuit.
Referring briefly to FIG. 2, an equation is provided to calculate the outgoing atomic flux per unit volume, referred to as the volumetric generation rate (∇·{right arrow over (J)} A ). As illustrated in FIG. 2, the equation can be used to calculate the volumetric generation rate due to a structural inhomogeneity, a temperature inhomogeneity, a current density inhomogeneity or a material inhomogeneity. For example, current density inhomogeneity can be caused by two imposed currents on a single metal lead with a single anode and a single cathode. Flux divergence is the difference between flux received and flux transmitted. In structural inhomogeneity, flux is not transmitted evenly due to voids or other structural imperfections in the metal lead. The depletion and accumulation regions are not bound to the cathode or anode. These processes take place wherever an inhomogeneity causes a volumetric generation rate greater than zero.
FIG. 2 also depicts temperature inhomogeneity. The temperature inhomogeneity leads to an inhomogeneous atomic flux distribution which causes areas of depletion and accumulation of atoms. Finally, FIG. 2 also represents the inhomogeneity due to mature constants. An inhomogeneity in the flux can be caused by an inhomogeneity of material constants. For example, inhomogeneity due to constants such as conductivity and diffusivity. These constants can be due to barrier layers between metals such as aluminum and copper in the metal lead.
As previously discussed (refer to FIG. 1 A), the transport of ions or atoms causes degradation and failure of metal connections in an integrated circuit. Thus, EM has remained a key variable in the design of integrated circuits. Designers compare interconnect direct charge average current per unit width, J′ eff , to a fixed limit. For example: S = Actual J eff ′ Design Limit J eff ′
where:
S represents current density ratio
J′ eff represents electrical current density per unit width in amps per centimeter
With appropriate modifications for contacts and alternating current lines the equation given above can be used to provide a conservative fixed limit. Previously, designers considered a design with S<1 a reliable design. Typically, designs producing S>1 have been subject to redesign.
However, from a reliability perspective, EM is inherently statistical. Failure times can vary widely for identically sized and stressed interconnects. An approach that factors EM failure statistics into the setting of EM design limits does not quantify chip reliability and does not reveal the relationship between S and EM risk. When reliable design is defined to mean achieving a chip-level reliability goal, fixed current density design limits become mathematically arbitrary. A design which has all interconnects to satisfy S<1 does not guarantee a reliable design. Similarly, a design including an interconnect with S>1 does not necessarily lead to an unreliable product. The total statistical risk is the critical variable in the design. Therefore, if each segment of interconnect at each stress level can be evaluated, the reliability goal can be distributed between interconnections. Distributing the reliability goal among classes of interconnections minimizes the performance limitation that an EM reliability goal places on the design.
Table 1 (below) demonstrates a typical non-linear relationship between maximum allowed current density and the number of violation corrections needed to reduce the current density below the allowable limit for a specific design.
TABLE 1
Current Density Limit
Number of
[amps/sq. cm]
Violations
3.17E6
9
2.58E6
17
2.10E6
52
1.71E6
97
1.39E6
162
1.13E6
337
0.93E6
616
Table 1 demonstrates that nine leads in the integrated circuit block must be redesigned (by widening the lead or other modification) to satisfy the current density limit of 3.17×10 6 amps per square centimeter. Similarly, for a current density of 2.58×10 6 amps per square centimeter, seventeen leads in the hypothetical integrated circuit block must be redesigned. Thus raising the allowable current density limit from 2.58×10 6 amps per square centimeter to 3.17×10 6 amps per square centimeter decreases from seventeen to nine the number of violations which must be addressed.
Still referring to Table 1, for a current density of 0.93×10 6 amps/cm 2 , 616 violations must be corrected before the current density design limit is satisfied. Thus, increasing the allowable current density design limit from 0.93×10 6 to 3.17×10 6 amps/cm 2 decreases the number of violations which must be satisfied from 616 violations to nine violations. Thus, the case illustrated by Table 1 shows that for an increase in the current density limit of approximately four times the number of violations that must be corrected is reduced by over 98%, a non-linear relationship. A preliminary VLSI design can have 2.1 million violations or more. Thus, increasing the allowable current density limit can have a significant impact on the number of potential violations to be addressed in a redesign.
FIG. 1B is a graph of the number of interconnects versus the current density distribution. As shown in FIG. 1B (and as previously noted in Table 1), the relationship between the number of interconnects and the current density distribution is non-linear. Thus, an increase in the allowable current density can be expected to disproportionately lower the number of violations.
The relation between the divergence of atomic flux and the time to failure can also be modeled mathematically. FIG. 3 shows the probability distribution function of the time to failure as a lognormal distribution. Thus, FIG. 3 shows the probability of failure at a given time. The area under the curve is normalized to one so that the percentage of failed devices can be calculated by integrating the area under the curve from time to failure equal zero (TTF=0) to the time of interest.
The percentage of failed devices at a given time based on the probability distribution function of the time to failure can also be estimated. FIG. 4 shows the cumulative distribution function in conjunction with the probability distribution function. The cumulative distribution function (CDF) defines the percentage of failed devices as a function of time. Based on the CDF the reliability can be calculated at a given time.
Data from accelerated testing are often used to estimate the failure distribution of each class of interconnect structures. Testing is accelerated using higher currents and temperatures than normal operating conditions. Often, the mode of failure in the accelerated test is assumed to be the same (or similar) to the failure mode under normal operating conditions. The failure distribution can be extrapolated for normal operations. Computer aided design tools determine the relative current stress S y and temperature acceleration factor A y at worst case operating conditions.
Designers can permit a certain number of connections which do not satisfy the reliability goal. Designing a circuit including a connection with greater than the current density design limit is known as “waiving an error” or “waiving a violation.” What is needed is a method to determine the number of violations which can be waived considering the temperature effects.
SUMMARY OF THE INVENTION
The interconnect system of layouts of VLSI designs are analyzed with respect to the electromigrations risk in order to ensure a reliable design. The electromigration risk is directly proportional to the current density and temperature. The current density can be obtained from electrical simulations for the metal lead and via system. The temperature can be estimated by thermal simulation. Thermal simulation can be performed using power dissipation of the circuitry as input. Based on simulations, calculated current densities can be compared to a current density limit. If the current density exceeds the current density limit the interconnect is identified for redesign. The number of such interconnects identified is usually very high. Thus, it can be necessary to waive a certain number of such violations.
The method taught uses the obtained current density and temperature distribution to predict which interconnects have to be redesigned in order to meet the reliability criteria. Thus, the method taught can determine the number of interconnects which must be redesigned to satisfy the reliability criteria. Thus, based on the reliability goal for the entire design specific, reliability levels will be assigned to blocks or parts of the design. After the layout phase the design of these blocks can be analyzed according to the method taught. The method allows analysis of part of a design and does not require analysis of an entire design.
In order to determine the number of violations which need to be addressed, the tool can perform an analysis assuming the violations above a certain level have been addressed. Based on the number of violations which have been addressed the method can calculate a new reliability. If the reliability is below the reliability criteria, the level of which violations have to be fixed will be lowered and the process starts again until the given reliability criteria is met. Therefore, the output is a specific list identifying the interconnect portions which are to be redesigned to meet the reliability criteria. The method can also identify an approximate amount by which to widen a metal lead to meet the desired reliability criteria.
The foregoing is a summary and this contains, by necessity, simplifications, generalizations and omissions of detail; consequently, those skilled in the art will appreciate that the summary is illustrative only and is not intended to be in any way limiting.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention may be better understood, and its numerous objects, features and advantages made apparent to those skilled in the art by referencing the accompanying drawings. The use of the same reference number throughout the several figures designates a like or similar element.
FIG. 1A depicts the particle mechanics of electromigration from an anode to a cathode. FIG. 1B depicts a graph of number of interconnects versus current density for a typical circuit.
FIG. 2 depicts application of a current flux calculation to current density inhomogeneity, a material inhomogeneity, a structural inhomogeneity and temperature inhomogeneity.
FIG. 3 depicts a plot of the probability distribution of the time to failure of a typical interconnect system.
FIG. 4 depicts the relationship between the probability of failure (PDF) at a certain time and the number of connects which will fail at this time.
FIG. 5 depicts an increase in the reliability of a system due to a decrease in the maximum current density in the design.
FIG. 6 depicts an assumption used to calculate reliability of the system, each metal lead connected in parallel.
FIGS. 7A-7D depict flow charts of embodiments of the disclosure.
FIG. 8A depicts a plot of a set of interconnect having an index and a reliability. FIG. 8B depicts a plot of the set of interconnects as shown in FIG. 8A with an incremental change in the index.
DETAILED DESCRIPTION
The following sets forth a detailed description of a mode for carrying out the invention. The description is intended to be illustrative of the invention and should not be taken to be limiting. As previously mentioned, metal particles migrate from cathode to anode by EM. The migration causes an area of depletion. The area of depletion is a cause of failure. EM is a function of atomic flux density which is given by: J ⇀ A = C D ( T ) k B T F ⇀ = α κ D ( T ) k B T J ⇀ Equation 1
where:
{right arrow over (J)} A is the atomic flux density
C is a concentration of metal atoms
α is a pre-factor which can include physical constants
κ represents the electrical conductivity of the metal lead
k B is the Boltzman constant
{right arrow over (F)} is a driving force in the diffusion process
T is temperature
{right arrow over (J)} is electrical current density
D(T) is a temperature dependent diffusion constant where : D ( T ) = D o e E A k B T
D o is a material dependent diffusion constant; and
E A represents the activation energy
Differences in current flux due to structure, current density, temperature and mature constants is mathematically defined as: ∇ · J ⇀ A = ∇ · α κ D ( T ) k B T J ⇀ Equation 2
where:
∇·{right arrow over (J)} A is the outgoing atomic flux per unit volume
α is a pre-factor, includes physical constants
κ represents the electrical conductivity of the metal lead
k B is the Boltzman constant
D(T) is a temperature dependent diffusion coefficient
T is temperature
{right arrow over (J)} is electrical current density
From Equation 2, it follows that: ∇ · J ⇀ A = C t Equation 3(a)
where:
∇·{right arrow over (J)} A is the outgoing atomic flux per unit volume
dC represents an incremental change in concentration of atoms or ions
dt represents an incremental change in time
FIG. 2 shows atomic flux divergence as produced by structural inhomogeneity, current density inhomogeneity, temperature inhomogeneity and material inhomogeneity. Equation 3(a) can be used to define the atomic flux divergence as shown in the as shown in FIG. 2, but Equation 3(a) is not limited and can be used to calculate the atomic flux under circumstances other than those shown.
The time to failure for one given metal lead can be estimated by Equation 3(b) below: TTF ( T , J ) = t fail = C critical - C o C t Equation 3(b)
TTF represents the time to failure
C o is the initial concentration of metal
C critical —concentration of metal at time of failure (the minimum concentration of metal needed to conduct current)
t fail represents time at failure
dC represents an incremental change in concentration of atoms or ions
dt represents an incremental change in time
Assuming a constant rate of dC/dt, Equation 3(b) gives the time to failure for a metal lead having initial concentration of metal C o . The time to failure is the time from C o to C critial and represents the time that a certain metal lead will fail. For processes that degrade over time, eventually reaching a failure state, one can use the lognormal distribution, as shown in Equation 3(c) below to describe the distribution of TTF's for a set of similar metal leads. f ( t ) = 1 σ t 2 π e - 1 2 σ 2 [ ln ( t ) - ln ( t 50 ) ] 2 Equation 3(c)
Where:
σ represents the standard deviation
t represents time
t 50 is the median time to failure
e represents the natural log
Equation 1 to Equation 3(c) model the mean time to failure as a function of the current density and the temperature. Alternatively, the mean time to failure can be calculated using Black's equation. Black's equation (see Equation 3(d) below) is used in conjunction with the lognormal distribution to calculate the mean time to failure for a specific metal lead depending on temperature and the current density. MTTF ( T , J ) = A J n e E A k B T Equation 3(d)
A represents a pre-exponential factor
J represents current density
T represents temperature
k B is the Boltzman constant
J represents current density
n represents the current density exponent
Black's equation simplifies the calculation of the mean time to failure using data which can be obtained from experiments. Using Black's equation, it is possible to extrapolate from the condition of the accelerated tests to the operating conditions. For example, activation energy (E A ) and current density exponent (n) can be obtained by experimental observation.
Based on the failure rate over time given by Equation 3(c), the percentage of failed devices at time t can be obtained by integrating. This integration, as shown in Equation 4(a) below, provides the cumulative failure distribution.
CDF=F ( t ) Equation 4(a)
Based on the percentage of failed devices at a specific time (t), given by F(t), one can calculate R(t) (the probability of surviving until time t) by Equation 4(b), below:
R ( t )=1 −F ( t ) Equation 4(b)
Equation 1 to Equation 4(b), as previously introduced, are used to calculate the reliability of one metal lead. However, the system reliability depends on the reliability of all metal leads which is represented by the chain of dependency given in Equation 5.
MTTF i ( J,T )→ F i ( t )→ R i ( t )→ R ( t ) Equation 5
F i (t) represents cumulative failure of the interconnect at time t
R i (t) represents reliability of one interconnect
R(t) represents the reliability of the complete system of interconnects
By using Black's equation (refer to Equation 3(d) ) the chain of dependency represented by Equation 5 can be extended. The chain of dependency now provides the relationship between the current densities in the set of metal leads and the system reliability. Mean time to failure is dependent on current density and temperature. A J i ″ e E A k B T = MTTF i ( J , T ) → F i ( t ) → R i ( t ) → R ( t ) Equation 6
Equation 6 illustrates the relationship between the mean time to failure based on the chain of dependency. The reliability of the system depends on the reliability of an item which depends on the probability of failure of the item.
FIG. 5 shows the relationship between the CDF and current density. If the current limit is reduced the CDF decreases at a given time. As shown in FIG. 5, decreasing the current limit increases the reliability. Therefore, if a maximum acceptable current limit decreases then the reliability of the system increases. However, current density can vary over time. As shown in Equations 7(a)-7(c), time varying current density can be used to calculate mean time to failure. Equation 7(c) provides an approximation of the mean time to failure based for a time dependent current density. An algorithm such as Equation 7(c) can be used to predict time to failure for a system having interconnects with varying current density. An algorithm such as Equation 7(c) is particularly applicable to a software solution. factor ′ = [ 1 + A D C ( J _ - J _ ) A A C J _ ] Equation 7(a) factor ″ = 1 J _ Equation 7(b) MTTF = ( 1 / factor ′ ) ( factor ″ ) A D C ( T ) J m - 1 Equation 7(c)
where:
A AC represents a prefactor for alternating current
A DC represents a prefactor for direct current MTTF = A J 2 e E A k B T Equation 8(a)
Equation 8(a) is similar to Equation 3(d), however the exponential in Equation 3(d) has been replaced with an exponent of two, which is used for aluminum. Aluminum is often used as the conductor in integrated circuits such as microprocessors. Hence Equation 3(d) is commonly used in the form represented in Equation 8(a). T = T substrate + J rms 2 κ A q R thermal Equation 8(b)
T substrate represents the substrate temperature
A q represents the cross-sectional area of the metal lead
κ represents the electrical conductivity of the metal lead
R thermal represents thermal resistance between metal lead and substrate
Equation 8(b) represents the temperature of the metal lead in the integrated circuit package. Equation 8(b) allows calculation of the increase in temperature between the metal lead and the silicon die. Thus, in many operating conditions the temperature of the metal lead will be higher than the temperature of the die due to the self-heating effect. Equation 8(b) corrects the temperature of the metal lead to include the thermal effect of the substrate.
Referring to FIG. 6 a representation of a series system is shown. Each component, (R 1 , R 2 , R 3 to R N ) is directly connected to the preceding component. In the event of a series system the reliability is the product of the reliability of all components, as represented by Equation 9:
R ( t )=Π i=1 N R i ( t ) Equation 9
According to the assumption made in Equation 9, if one interconnect fails, then the system fails. In the case of an electrical system in a series configuration, if one interconnect fails then the system fails. Based on this assumption, there are no alternate paths in the system. Without alternate paths, failure of any connection leads to a failure of the system. Using the assumption of a series system, Equation 9 allows calculation of the reliability of the system based on the reliability of the metal leads.
The method above can be used to facilitate the design of an integrated circuit, such as a VLSI integrated circuit, or microprocessor. As depicted in FIG. 7A-D, the method determines an acceptable current density for a metal lead, step 705 . The method also determines an acceptable reliability for an integrated circuit, step 704 . From steps 704 and 705 , the method next provides a first design for an integrated circuit, step 710 . From step 710 , the method determines a first current density for the (first) set of metal leads, step 715 . From step 715 , the method determines a (first) subset of the first set of metal leads, step 720 .
From step 720 , the method calculates a (first) mean time to failure, step 725 . It is assumed that the metal leads are connected in series, step 730 . Step 730 is depicted as sequential to step 725 but a method according to this embodiment of the present invention should not be limited to such a configuration. Step 730 can occur anytime before the (first) reliability of the integrated circuit is calculated, step 735 . After step 735 , the method proceeds to decision 745 . Decision 745 determines if the reliability of the system exceeds the acceptable reliability. If the reliability of the system exceeds the acceptable reliability, the method stops, step 746 . If the reliability of the system is less than the acceptable reliability, the method proceeds as shown in FIG. 7B or FIG. 7 C.
In one embodiment, the method proceeds from step 745 to prove an n th design for the integrated circuit, step 750 . In one embodiment, metal leads with higher-than acceptable current density are redesigned to reduce the current density in the iterative design. After the n th design is completed, the method proceeds to determine the n th current density for the n th set of metal leads, step 755 .
From step 755 , the method calculates an n mean time to failure, 765 . The n th mean time to failure corresponds to the mean time to failure of the metal leads corresponding to the n th design. From step 765 the method calculates the reliability of the integrated circuit, step 770 . From step 770 , the method determines if the n th reliability of the system exceeds the acceptable reliability, step 775 . If the n reliability of the integrated circuit exceeds the acceptable reliability, the method can stop, step 785 . If the n th reliability of the system is less than the acceptable reliability of the system, the counter is incremented and the method proceeds to step 750 . Step 750 is an earlier step in the method, hence the embodiment depicted in FIG. 7B is an iterative process.
In one alternative embodiment, the method again proceeds from step 745 (previously shown in FIG. 7A) to provide an n th design for the integrated circuit, step 750 . A determination is then made to the current density for each metal lead in the n th set of metal leads, step 756 . (In one embodiment, determining the current density in the n th set of metal leads includes determining the current density of each metal lead in the n th design.) From step 756 the method proceeds to calculate the mean time to failure for each metal lead, step 761 . From step 761 the method proceeds to calculate the reliability of each metal lead, 771 . From step 771 , the method proceeds to calculate the reliability of the system, step 781 .
From step 781 , the method determines of the calculated reliability of the system exceeds the acceptable reliability, step 782 . The acceptable reliability of the system was previously determined in step 704 . If the calculated reliability of the system exceeds the acceptable reliability, the method stops, step 786 . If the calculated reliability of the system is less than the acceptable reliability, the method continues.
From step 782 (also referred to as decision 782 ), the method proceeds to sort the n th set of metal leads by reliability, step 791 . The set of metal leads can be sorted in ascending or descending order. Typically, the set of metal leads is sorted in descending order. From step 791 , the method divides the (previously sorted) set of metal leads into at least two subsets; subset A and subset B. One subset includes the metal leads of lowest reliability. For convenience, the subset including the metal leads of lowest reliability is referred to herein as subset A.
From step 793 , the method proceeds to repair metal leads in subset A. Typically, repair of metal leads involves redesign of the integrated circuit to widen the metal leads. From step 794 , the method proceeds to increment the counter, step 795 . Any logical counter can be used. In this instance index “n” (also referred to as a “logical counter” is used for convenience. Incrementing the logical counter allows the method to proceed in an iterative loop within previously determined constraints. For example, an analyst may decide to allow, the loop (as shown in FIG. 7C) to proceed for only 100 iterations by stopping the method when n equals one hundred. In another instance, the analyst can decide to allow the method to continue for a greater number of iterations. From step 795 , the method continues to step 750 . It will be noted that step 750 has been previously performed by the method, thus the method can be said to be “circular” or iterative.
In yet another alternative embodiment, the method can be performed without iteration. In this embodiment (shown in FIG. 7 D), steps 782 and 795 are omitted. Other steps (for example, steps 781 , 791 , 793 and 794 ) are as previously described. However, the method is performed in only one pass, as shown in FIG. 7 D. Thus, the method is not limited to iteration. Equation 10, below, shows a method of performing the method in a single pass, without iteration.
R req ≦R ( t )= R j ( t ) j−1 Π i=j N R i ( t ) Equation 10
Referring to FIG. 8A, a plot is shown of reliability (R) on the X axis and index on the Y axis. It will be recalled, that the index (denoted in this case by subscript i) is used to identify the reliability of the individual metal leads. After calculating the reliability of each metal lead the set of metal leads is sorted by reliability. In one enablement of the invention, the set of metal leads are sorted from lowest reliability to highest. Each metal lead is assigned an index number; the index number is a sequential number incremented by one. Thus, an index number can be used to find the previously calculated reliability of a corresponding metal lead. Equations 3(c), 3(d) and 4(b) are used to calculate the individual reliability of metal leads.
Referring now to FIGS. 8A and 8B, a metal lead is chosen arbitrarily. Assuming a metal lead corresponding to index j is chosen; the corresponding reliability of the metal lead is known as identified as R j in FIGS. 8A and 8B. The next step in the sequence is to define the reliability of all interconnects in the first subset having a reliability of less than R j equal to the reliability of R j . The reliability of the system is calculated again. If the reliability of the system exceeds the acceptable reliability then only those metal leads having an index of j or less must be repaired in order to meet the specified system reliability. As shown in FIG. 8B, index j can be decreased until the calculated reliability of the system is approximately equal to the acceptable reliability.
If the reliability of the system is less than the desired reliability, then j is increased incrementally. In this manner, again, the minimum number of metal leads to be repaired is determined. In one embodiment of the method, for illustrative purposes only, it is assumed that the number of metal leads in a system is one million. Now referring to FIG. 8B, index i will range from one to one million. Now, again for illustrative purposes assume the reliability of the metal leads ranges from 0.10 to 0.99. Thus, R in FIG. 8B will range from 0.10 to 0.99, or more. Subsequently, it is assumed that the metal lead corresponding to a reliability of 0.10 is initially chosen as the dividing point. Thus, the metal lead corresponding to 0.10 has an index of j. Thus, all metal leads having an index less than j have a reliability less than 0.10. All metal leads having an index greater than j have a reliability greater than 0.10.
In the example of the preceding paragraph, the reliability of each metal lead with an index greater than j is held constant. It is assumed that reliability of each metal lead with an index of less than j equals the reliability of metal lead with index j. Thus, in effect, it is assumed that the reliability of all metal leads in the first subset equals the lowest reliability of the metal leads in the second subset. Now calculate the reliability of the system. If the reliability of the system exceeds the acceptable reliability only those metal leads in the first subset (or fewer) must be repaired to meet the minimum system reliability. If the reliability of the system is less than the acceptable reliability, increase j by an increment and again calculate the reliability of the system. Thus, in an incremental method the minimum number of metal leads to be repaired can be determined.
The method disclosed is not restricted to a specific software, software language or software architecture. Each of the steps of the method disclosed may be performed by a module (e.g., a software module) or a portion of a module executing on a computer system. Thus, the above component organization may be executed on a desk top computer system or other data processing system. The method may be embodied in a machine-readable and/or computer-readable medium for configuring a computer system to execute the method. Thus, the software modules may be stored within and/or transmitted to a computer system memory to configure the computer system to perform the functions of the module.
The operations described above and modules therefor may be executed on a computer system configured to execute the operations of the method and/or may be executed from computer-readable media. The method may be embodied in a machine-readable and/or computer-readable medium for configuring a computer system to execute the method.
While particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that, based upon the teachings herein, changes and modifications may be made without departing from this invention and its broader aspects. Therefore, the appended claims are to encompass within their scope all such changes and modifications as are within the true spirit and scope of this invention. Furthermore, it is to be understood that the invention is solely defined by the appended claims.
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A method of designing an integrated circuit calculates the current density in each metal lead. The method can calculates a mean time to failure for at least one metal lead. Calculation of the mean time to failure can include the current density and the temperature. The method can assume the metal leads are arranged in series only. The method can calculate the reliability of the integrated circuit based on temperature effects. The method can arrange the set of metal leads by reliability. The method can divide the set of metal leads into at least two subsets, a subset requiring redesign and a subset meeting the reliability criteria. An embodiment includes an integrated circuit designed by the method taught. An embodiment includes a computer program product according to the method taught. An embodiment includes an integrated circuit including an integrated circuit designed according to the computer program product.
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BACKGROUND OF THE INVENTION
The present invention relates to metal masses adapted for internal oxidation to generate dispersion strengthening by the in situ formation of hard, refractory oxide phases therein, and a process for dispersion strengthening which utilizes said metal masses.
In the past, it has been recognized that strength and hardness can be imparted to a solid solution alloy of ductile matrix metal, and a solute metal, the matrix metal having relatively low negative free energy of oxide formation, and the solute metal having a relatively high negative free energy of oxide formation. A substantial difference in negative free energy of oxide formation between matrix metal and solute metal is essential here. The negative free energy of oxide formation is a measure of the ease with which a metal will oxidize. A metal with a low negative free energy of oxide formation is difficult to oxidize, and a metal with a high negative free energy of oxide formation is easy to oxidize. By heating the alloy under oxidizing conditions, the solute metal preferentially oxidizes to cause the in situ formation of hard, refractory oxide particles in the matrix metal, substantially wlthout oxidizing the matrix metal. This technique is known as the in situ internal oxidation of the solute metal to the solute metal oxide, or simply "internal oxidation". In internal oxidation, the matrix metal is relatively noble compared to the solute metal so that the solute metal will be preferentially oxidized.
The hard, refractory metal oxides formed in the matrix metal cause the alloy to be dispersion strengthened. Dispersion strengthening imparts to these materials a high strength, a high electrical conductivity and a high heat resistance. Dispersion strengthened metal products, such as copper dispersion strengthened with aluminum oxide, have many commercial and industrial uses where high temperature strength, high electrical conductivity, and/or heat conductivity are desired or required. Such uses include frictional brake parts such as linings, facings, drums, and the like and other machine parts for frictional applications, contact points for resistance welding electrodes, electrodes generally, electrical switches and electrical switch gear, transistor assemblies, wires for solderless connections, wires for electrical motors, lamp leads, and many other related applications. The metal masses of the present invention are useful in the production of dispersion strengthened products for the above and other applications.
In the past, attempts have been made to dispersion strengthen alloys by various methods of internal oxidation. These methods may be divided into two categories. The first category is powder metallurgical processes. The second category is internal oxidation of bulk alloy masses. In the first category, U.S. Pat. No. 3,026,200 shows the surface oxidation of alloy powder followed by a heat treatment in an inert atmosphere to diffuse oxygen from the surface of the alloy to preferentially oxidize the solute metal to solute metal oxide within the alloy powder.
U.S. Pat. No. 3,184,835 discloses the internal oxidation of copper-beryllium or copper-aluminum alloys wherein the oxidant is a sintered and milled mixture comprising about 50% copper oxide and about 50% aluminum oxide. The sintered oxidant residue is physically separated from the internally oxidized alloy powder before the powder is formed into dispersion strengthened metal products. The use of this sintered mixture as the oxidant is said to minimize adhesion of the oxidant residue to the internally oxidized alloy.
U.S. Pat. No. 3,779,714 discloses a process for the internal oxidation of alloy powders, for instance copper-aluminum alloy powders, wherein the oxidant is a blend of a heat-reducible metal oxide and a finely divided hard, refractory oxide. This oxidant blend is disposed such that after oxidation of the alloy powder is accomplished, the oxidant residue has substantially the same net composition as the internally oxidized alloy powder, and thus does not have to be removed.
In each of these cases, dispersion strengthened alloy powders are produced before any shapes or articles are attempted to be made from the powders. Such forming procedures after internal oxidation have proven to be very difficult because of the high strength of the dispersion strengthened alloy powders.
In the second category bulk alloy masses are internally oxidized. U.S. Pat. No. 3,399,086 discloses the internal oxidation of copper-aluminum alloy in plate or strip form using copper oxide as the oxidant. The shape to be oxidized is packed in the oxidant. The copper oxide is reduced to give up its oxygen for the preferential oxidation of the alloyed aluminum to form interspersed particles of aluminum oxide within the copper matrix. This process is disclosed as often taking several hours, and then, is usually only effective to dispersion strengthen a relatively thin section of the plate or strip surface.
U.S. Pat. No. 3,552,954 discloses a process for the internal oxidation of alloy strips. According to this process, the alloy strip is internally oxidized under a controlled atmosphere and then reduced in the presence of hydrogen to remove excess oxygen. The alloy strip is then pulverized and reformed into the final dispersion strengthened product. In this patent, it is disclosed that the original processed alloy strip was an unsuitable dispersion strengthened product because of excessive hydrogen embrittlement.
U.S. Pat. No. 3,615,899 discloses another method for the bulk internal oxidation of alloy parts. In this process, the alloy part is packed in a cuprous oxide oxidant which contains an inhibitor oxide. The oxidant blend is controlled to provide a maximum internal oxidation velocity. The maximum internal oxidation velocity is said to be required to produce optimum properties in the finished alloy part.
All of the prior art methods in this category dispersion strengthen a bulk alloy part by exposure to an oxidizing environment only at its surface which requires an extremely long period of time and/or the ultimate properties of the alloy are compromised by concomitant reactions which detract from ultimate performance.
One benefit of the present invention is that a cohesive mass of alloy powder and oxidant is formed and at least partial densification takes place before internally oxidizing to dispersion strengthen. Therefore, this forming requires less energy, less force, and produces less die wear than when forming is subsequent to dispersion strengthening.
Another benefit of the present invention is that it produces more intimate contact between the alloy to be internally oxidized and the oxidant. This improved contact decreases internal oxidation time and improves oxygen transfer from oxidant to solute metal in the alloy.
A further benefit derived from the present invention is that a preformed shape can be dispersion strengthened uniformly throughout and in a fraction of the length of time previously required for dispersion strengthening of preformed shapes.
SUMMARY OF THE INVENTION
The present invention is a preformed charge stock for making a mass of dispersion strengthened metal by internal oxidation and a process for making a dispersion strengthened metal mass utilizing said charge stock. The preformed charge stock is a coherent mass made of an intimate interspersion of alloy particles and oxidant. The alloy contains matrix metal and solute metal. The matrix metal has a low negative free energy of oxide formation, and the solute metal has a high negative free energy of oxide formation, such that there is a substantial difference between the negative free energies of oxide formation of matrix metal and solute metal. The oxidant is a heat-reducible metal oxide having a predetermined negative free energy of oxide formation such that it can oxidize solute metal, but not matrix metal. The amount of oxidant present is adequate for oxidizing, under internal oxidation conditions, sufficient of the solute metal to impart dispersion strengthening of the matrix.
The present process for making a dispersion strengthened metal mass utilizes the above preformed charge stock. The preformed charge stock is first made by forming a coherent mass of alloy powder and oxidant. The preformed charge stock is then internally oxidized by heating until the solute metal portion of the alloy powder is sufficiently converted into hard, refractory oxide particles to impart dispersion strengthening of the matrix metal. Optionally, the dispersion strengthened product is then further shaped and/or densified.
DETAILED DESCRIPTION OF THE INVENTION
In achieving the objects of the present invention, one feature provides for the formation of a coherent mass of intimately blended alloy powder and oxidant.
It has been discovered that making a preformed charge stock of alloy powder and oxidant is substantially easier than forming fully dispersion strengthened alloy powder, even if their net compositions are approximately the same. For example, it takes less force to form a blend of alloy powder and oxidant into a cohesive mass of a given percentage of theoretical density than to form dispersion strengthened metal of the same net composition into the same shape of the same density. This reduced force will also result in reduced wear of the forming dies and a reduction in lamination during forming. Laminations are cracks which form early in a forming process and tend to close later, but remain as weak sites in the finished product. The coherent mass so formed has further been found to be stronger and more ductile than preforms made of dispersion strengthened metals. This property will be found to be particularly beneficial if the coherent mass is subsequently rolled, forged or swaged.
The alloy powder is an alloy of matrix metal and solute metal. The alloy powder can be spheroidal, flake or irregularly shaped. It is intimately blended with oxidant in a preformed charge stock adapted for the internal oxidation of solute metal to solute metal oxide. Said matrix metal has a negative free energy of oxide formation per gram atom of oxygen at 25° C. ranging from 0 to 70 kilocalories. The netative free energy of oxide formation of the solute metal oxide exceeds the negative free energy of oxide formation of the matrix metal oxide by at least 60 kilocalories per gram atom of oxygen at 25° C. The intimately admixed oxidant comprises a pulverulent, in situ, heat-reducible metal oxide having a negative free energy of oxide formation at 25° C. less than that of the solute metal, such that it can oxidize solute metal. Optionally, the oxidant can contain an interspersion of discrete particles of hard, refractory oxide. In such case, the negative free energy of oxide formation of said hard, refractory oxide exceeds the negative free energy of oxide formation of said heat-reducible metal oxide, usually by at least about 60 kilocalories per gram atom of oxygen at 25° C. Preferably, the hard, refractory oxide is present in a proportion and particle size adapted for dispersion strengthening of the oxidant residue resulting from internal oxidation.
The heat-reducible metal oxide can contain the same or different metal moiety from the matrix metal of the alloy. Similarly, the hard, refractory oxide can be the same or different metal oxide than results from the internal oxidation of the solute metal to solute metal oxide in the alloy.
The pulverulent, in situ, heat-reducible metal oxide in the oxidant is preferably in substantial stoichiometric proportion for internal oxidation of all the solute metal to solute metal oxide in the alloy. This proportion can, however, broadly vary as much as ±50% or more. Such variation can be required under some circumstances to be effective. After internal oxidation, the oxidant residue comprises uniformly distributed agglomerates consisting of in situ reduced metal and optional particles of hard, refractory oxide. These agglomerates are in intimate mixture with the particles of internally oxidized alloy in the coherent mass.
Suitable matrix metals for practicing this invention include the following: iron, cobalt, nickel, copper, thallium, germanium, tin, lead, antimony, bismuth, molybdenum, tungsten, rhenium, indium, silver, gold, ruthenium, palladium, osmium, platinum, and rhodium. Mixtures of suitable matrix metals and alloys thereof can also be used.
Suitable solute metals for practicing this invention include: silicon, titanium, zirconium, aluminum, beryllium, thorium, chromium, magnesium, manganese, niobium, tantalum, and vanadium.
Suitable heat-reducible metal oxides for use as the oxidant for practicing this invention include: FeO, Fe 2 O 3 , CoO, NiO, Cu 2 O, CuO, Tl 2 O, GeO 2 , SnO, SnO 2 , PbO, Sb 2 O 3 , Bi 2 O 3 , MoO 3 , MoO 2 , WO 2 , WO 3 , ReO 3 , In 2 O 3 , Ag 2 O, Au 2 O, RuO 2 , PdO, OsO 4 , PtO, and Rh 2 O 3 .
Suitable hard, refractory oxides for use in practicing this invention include the following: SiO 2 , TiO 2 , ZrO 2 , Al 2 O 3 , BeO, ThO 2 , Cr 2 O 3 , MgO, MnO, Nb 2 O 5 , Ta 2 O 5 , and VO.
Suitable matrix metal/solute metal/oxidant combinations useful in practicing this invention include: Cu/Al/Cu 2 O, Ni/Al/NiO, Ni/Be/NiO, Ni/Zr/NiO, Fe/Al/FeO-Fe 2 O 3 , Ag/Al/Ag 2 O, Cu-Ni/Al/NiO, and Ag/Mg/Ag 2 O.
Preferably, the in situ heat-reducible metal oxide in the oxidant contains the same metal moiety as the matrix metal in the alloy powder. Preferably also, the optional hard, refractory oxide in the oxidant contains the same metal moiety as the solute metal in the alloy powder. In one particularly commercially important embodiment of this preferred practice, the oxidant contains substantially the same proportions of matrix metal moiety and solute metal moiety as are present in the alloy powder. Thus, upon internal oxidation of the preformed charge stock, the oxidant residue itself is of substantially the same composition as the internally oxidized alloy and becomes dispersion strengthened herewith.
Another feature of the present invention resides in a preformed charge stock composition based upon an alloy of matrix metal and about 0.01 to about 5% by weight solute metal adapted for further coalescence upon hot working to form dispersion strengthened metal articles. To achieve the proper proportion of oxidant, said composition further comprises about 0.1 to about 10 parts by weight of oxidant per 100 parts of alloy. The exact proportions depend on the solute metal to be oxidized, its concentration in the alloy and the oxygen content of the oxidant.
The preformed charge stock can further comprise a small proportion of a fugitive binder without departing from the essence of this invention. Said binder must be carefully selected such that no residue is left after the internal oxidation step. Such residue would be detrimental to the ultimate properties of the finished workpiece. Suitable binders are ammonium alginate, starch, starch glyceride, polyvinyl alcohols, Carbowax, furfuryl alcohol resins, polyvinyl acetate, oils and other liquids.
According to the process of the present invention, the oxidant is intimately admixed with alloy particles. The mixture is formed into a charge stock and the charge stock is subjected to internal oxidation conditions. After the preformed charge stock is internally oxidized, the oxidant residue remains as a portion of the final product. The oxidant residue is present, however, in such small proportions that it does not significantly adversely affect the properties of the finished product. Optionally, this oxidant residue additionally contains fine particles of a hard, refractory oxide, which can serve to dispersion strengthen the oxidant residue to form an integral part of the resulting workpiece.
Mixing of alloy particles and oxidant can be carried out in any convenient and effective manner. Obtaining an intimate, homogeneous admixture, however, is very important, because it is theorized that the oxygen atmosphere within the coherent mass cannot equalize as readily as it can when the powder is loosely filled in a tray or other container. Ball milling or other such grinding techniques has been found to be particularly advantageous for this mixing operation (e.g. Hardinge conical ball milling, dry pan muller mixing, and enclosed cage milling using variously shaped grinding media, such as cylinders, pyramids, cones and double cones). It not only provides an intimate homogeneous admixture, but also is believed to break up surface oxides on the alloy powder, causes some oxidant to be driven into the alloy powder particle surface, and flattens some of the alloy powder particles. Regardless of theory, ball milling or other such conventional grinding techniques used for mixing of alloy powder and oxidant has been shown to increase the rate at which sintering occurs and has been shown advantageous in attempts to lower the temperature and time required for internal oxidation. Parts formed from such powder exhibit improved interparticle bonding and more uniform dispersion strengthening.
The intimate blend of oxidant and alloy powder is then formed into a charge stock. This formation process may be any conventional forging, rolling, extruding, swaging, or pressing process or otherwise. The preformed charge stock may be only partially dense, for example, 60% of theoretical density, on up to fully dense (100% of theoretical density) with no voids. This is a greater degree of flexibility in forming techniques than is possible for regular dispersion strengthened metal powders. If, for example, dispersion strengthened metal powder made pursuant to prior art instructions is pressed directly to 90% of theoretical density, it tends to laminate (crack) and give rise to weak spots after subsequent sintering. However, a preformed charge stock of the present invention formed by pressing directly to 90% theoretical density does not develop cracks or weak spots during sintering.
This step of the process can be performed continuously or stepwise. It has been found advantageous for the formation of certain extrudable shapes to use a continuous powder extruding process. Such a process will continuously compress powder and expel an extruded strand of alloy power and oxidant blend. An apparatus for one such process is disclosed in U.S. Pat. No. 3,765,216 the disclosure of which is hereby incorporated herein by reference. This apparatus is particularly adapted to extruding metal powders, and is termed a "Conform machine". Its use is described as a metal extrusion process in which the force for extrusion of the metal through a die is derived, at least in part, by maintaining frictional engagement of the metal with passageway defining surfaces of a member which is moved towards the die such that frictional drag of the passageway defining surfaces urges the metal through the die. The use of this machine allows the production of a continuous wire or rod-shaped part by continuous feeding of alloy-powder/oxidant blend. The length of the part formed is not limited by the size of the original charge that can be placed in the machine.
The internal oxidation operation is preferably carried out at a temperature in the range of 1400° F. to 1700° F. Lower temperatures can be used such as about 1200° F. or below with very little sacrifice in properties or efficiency particularly when the preformed charge stock is formed from a blend of alloy powder and oxidant which is rendered particularly intimate by use of a ball mill or the like. Higher temperatures also can be used with some reduction in time required for the complete formation of the oxide, but close temperature control is then necessary to avoid local overheating which might result in partial or incipient fusion of the metal. This step of the process can also be performed stepwise or on a continuous basis.
Annealing to increase grain size can be practiced before or in combination with the internal oxidation operation. Solute metal oxide tends to concentrate at grain boundaries in the alloy powder. This is undesirable because it can cause early failure under stress at these grain boundaries. It is, therefore, often desirable to reduce the grain boundary area in the alloy powder and this is accomplished by annealing the powder to form a larger grain size. The annealing operation can be performed on the alloy powder before formation of the preformed charge stock, or it can be practiced on the preformed charge stock before or in conjunction with the internal oxidation operation. When alloy powder is to be annealed to increase grain size, this step should be subsequent to all milling operations on the powder, because milling will tend to reduce the grain size. For copper-aluminum alloys, which are one of the more commercially important embodiments of the present invention, annealing temperatures of about 1600° F. for one hour in an inert atmopshere such as argon, produce an acceptable grain size of at least about ASTM grain size No. 6 by ASTM Test E-112. If annealing is practiced in combination with internal oxidation, the annealing temperature and atmosphere should be controlled so that the grain size will increase to the desired dimensions before internal oxidation takes place.
The time required for the internal oxidation of the preformed charge stock is similar to the time required for internal oxidation of powders rather than the previously reported time required for internal oxidation of bulk alloy parts. This is because the oxidant is intimately interspersed throughout the charge stock such that oxygen released from the oxidant has only a very short distance to travel to effect internal oxidation of the alloy particles regardless of the outside dimensions of the charge stock.
Further, it has been found there is more intimate contact between the oxidant and alloy particles within the charge stock than there is in a mere loose physical blend of oxidant and alloy particles. This increased contact in some cases will actually allow internal oxidation to proceed at a faster rate for the charge stock than it will for loose powders, particularly if the alloy powder and oxidant were milled together rather than just blended.
Alloy powders suitable for use in the process of the present invention typically have a maximum dimension of about 280 microns and preferably have a maximum dimension of about 140 microns. The ratio of the average largest dimension of the alloy particles to the largest dimension of the oxidant particles should be at least about 2:1 and usually is between about 5:1 and about 30:1 or even higher if practical. This is to provide desirable interparticle contacts for efficient reaction and to maximize homogeneity of the final product. Generally, the oxidant particles are micron or sub-micron in particle size.
There are several methods for incorporating the optional refractory oxide particles in the oxidant of the present invention. In one method, an oxide forming salt of the refractory is applied to and decomposed on a particle of a heat-reducible metal oxide having a particle size in the micron or sub-micron range. In the case of the copper-aluminum system, for instance, sub-micron cuprous/cupric oxide particles are treated with an aqueous solution of aluminum nitrate so as to form a uniform coating. The particles are dried and heated to decompose the aluminum nitrate and form cuprous/cupric oxide particles having a uniform coating of aluminum oxide thereon. The amount of aluminum nitrate added is predetermined according to the aluminum oxide content desired in the final product. In another method, micron or sub-micron particles of heat-reducible metal oxide and refractory oxide particles are intimately blended in a blending device to provide the oxidant.
Internal oxidation of a preformed charge stock composed of the previously described materials can be advantageously accomplished in about 30 minutes to 1 hour. Shorter periods of time are possible where the alloy particles and oxidant particles are smaller or the oxidation temperature is increased. Similarly, the oxidation time can be longer if the particles are larger in size or the oxidation temperature is reduced. In either case, it is important to note that the oxidation time is correlated to the distance the oxygen must travel and not to the size of the charge stock. In the charge stock oxygen must only travel only about the same distance as oxygen must travel in a loose oxidant and alloy powder mixture.
Strength and density of the internally oxidized dispersion strengthened product can be further increased by hot or cold working the dispersion strengthened product. The increase in strength thus obtained is substantially retained even when the worked dispersion hardened product is heated above the annealing temperature of the matrix alloy. Also, if the oxidant contains the optional refractory oxide component, the further working of the internally oxidized dispersion strengthened product can serve to dispersion strengthen the oxidant residue.
The following examples show ways that we have operated this invention. The examples should not be construed as limiting the invention. All temperatures are given in degrees Fahrenheit and all percentages are weight percentages, unless otherwise specified.
EXAMPLE 1
Oxidant was prepared by blending 98.6 parts of commercially available cuprous oxide (Cu 2 O) with 1.4 parts of Al 2 O 3 of about 0.01-0.02μ particle size. Blending was accomplished by rolling the powders in a glass jar with three 1" porcelain mill balls.
Sixty (60) g of oxidant and 1,000 g of atomized alloy powder were then ball milled together for 8 hours in a steel-lined ball mill using steel balls. The alloy powder contained 99.4% Cu and 0.6% Al and would substantially pass through a 60 mesh screen and be retained on a 325 mesh screen (Tyler Standard Sieves). Copper (Cu) can oxidize to form CuO and/or Cu 2 O. Aluminum (Al) can oxidize to form Al 2 O 3 . Similarly CuO and Cu 2 O can be reduced to form Cu and Al 2 O 3 can be reduced to form Al. The negative free energies of oxide formation at 25° C. for CuO, Cu 2 O, and Al 2 O 3 are 32, 35, and 126 kilocalories per gram atom of oxygen, respectively. The oxidant level represents 90% of the amount of oxidant calculated to be required to fully oxidize the aluminum present in the alloy. Note also that ball milling in air will tend to oxidize some of the copper to copper oxides and thus make up at least part of the oxidant deficiency.
Fifteen (15) grams of the oxidant/alloy blend was placed in a die measuring about 1/2"×1-1/8" and pressed at 32,000 lbs./sq. in. using a hydraulic press. This pressure was predetermined to yield a part having 80% of theoretical density. Six samples were so produced.
The samples were heated for various times and temperatures as shown in Table 1. This caused concomitant sintering and internal oxidation. Transverse rupture strength was then determined in accordance with ASTM test B 528-70 (Transverse Rupture Strength of Sintered Metal Powder Specimens), the disclosure of which is expressly incorporated herein by reference. This data is shown in Table 1.
This test is designed to generate data and calculate "transverse rupture strength". It defines the stress, calculated from the flexure formula, required to break a specimen as a simple beam supported near the ends and applying the load midway between the fixed center line of the supports.
Transverse rupture strength is calculated as follows:
TRS=(3XPXL)/(2Xt.sup.2 XW)
where:
TRS=transverse rupture strength of the sintered compact, in psi,
P=load, lbf, required to rupture the specimen,
L=length of specimen span of fixture, in. (1.00 in.),
W=width of the specimen, in., and
t=thickness of specimen, in.
EXAMPLE 2
Commercially available dispersion strengthened alloy power with the same net composition as the samples produced in Example 1 was obtained. This powder is designated AL-60 and is available from Glidden Metals, 1468 West 9th Street, Cleveland, Ohio 44113. It was prepared in accordance with U.S. Pat. No. 3,779,714, the disclosure of which is expressly incorporated herein by reference.
Six (6) parts were made by pressing at 49,000 psi and sintering as described in Example 1. Transverse rupture strength was determined and the data is shown in Table 1.
EXAMPLE 3
In the procedure of Example 1, six parts were produced by pressing at 75,000 lbs./sq. in. This pressure was predetermined to yield a part of about 90% of theoretical density. Transverse rupture strength data is shown in Table 1.
EXAMPLE 4
In the procedure of Example 2, six parts were produced by pressing at 97,000 lbs./sq. in. These parts formed laminates (cracks) during sintering that prevented accurate transverse rupture strength determinations.
TABLE 1______________________________________TRANSVERSE RUPTURE STRENGTH DATA SinteringSintering Temperature, Parts of Parts of Parts ofTime °F. Example 1 Example 2 Example 3______________________________________1 hour 1600 10600 -- 26900 1750 -- 10200 -- 1800 16400 -- 37800 1850 -- 11500 -- 1900 -- -- -- 1950 22200 14200 393007 hours 1600 12200 -- 28300 1750 -- 11300 -- 1800 17200 -- 39300 1850 -- 15700 -- 1900 -- -- -- 1950 26600 18200 63900______________________________________
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This invention relates to dispersion strengthening of metals. A coherent mass comprising an intimate blend of alloy powder and oxidant is formed prior to dispersion strengthening. Said coherent mass is easily formed because the alloy powder is not yet strengthened, and undergoes internal oxidation rapidly because of the intimate blend of alloy powder and oxidant.
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CROSS-REFERENCE TO RELATED APPLICATIONS
Not Applicable
STATEMENT REGARDING FEDERAL SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
REFERENCE TO SEQUENCE LISTING, ETC.
Not Applicable
BACKGROUND
The present invention relates to a chemical glow device that is reusable and rechargeable. More particularly, the present invention relates generally to a glow device that can be reused many times by being refilled with the necessary chemicals while at the same time being rechargeable between refills, so each refill can afford multiple uses of the glow device.
Lighting devices based on chemiluminescent emission generated by the mixing of two chemicals are already commonly known. See U.S. Pat. No. 4,678,608 which is incorporated in the present description by reference. The chemiluminescence is produced by a reaction in the liquid phase of an activator such as hydrogen peroxide with a flourescent agent and an oxalate. Optionally, other secondary compounds may also be present, generally flourescent agents modifying the characteristics of the emitted light.
Also known is a method by which such devices can be made of translucent synthetic material containing two chambers whereby external force is applied to the device until the membrane separating the two chambers moves and/or fails and a chemical reaction is seen producing chemiluminescence. See U.S. Pat. No. 5,552,968 which is incorporated in the present description by reference. Further it is well known that the chemicals involved can be chosen and/or manipulated to obtain a variety of colors of chemiluminescent light, such as red or orange. See U.S. Pat. Nos. 5,122,306 and 6,461,543.
Notwithstanding the above, these prior devices have been limited to single-use or single chemical reaction devices. Thus, there exists a significant demand for a device that provides chemiluminescent light which is reusable and rechargeable.
BRIEF SUMMARY
The present invention is directed to the needs and desires noted above for a reusable and rechargeable glow device that can be reused by refilling the device with the necessary chemiluminescent chemicals and also rechargeable between refills by using a graduated system of introducing the chemiluminescent liquids to produce chemiluminescent light. It is a further object of this invention that a user be allowed to adjust the amount of light or glow provided by adjusting the amount of chemiluminescent chemicals mixed together through use of the graduated system or device. Furthermore, it is an object of this invention that the device be a variety of sizes and/or shapes depending upon the needs of the user, produce a variety of light colors and be producible at a low cost to allow many people to purchase and use these devices.
These and other features, aspects and advantages of the present invention will become better understood with reference to the following description, appended claims and accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 : shows a schematic of one claimed embodiment.
DESCRIPTION
The reusable and rechargeable glow device of this invention may be produced by use of a container having translucent features and containing two chambers. Each chamber contains at least one chemical product which reacts with the other chemical to produce a chemiluminescent reaction. The chemicals of the two chambers are mixed in a gradual manner through use a system by which the amount of the chemicals mixed can be manually adjusted by the user. This flexibility will allow the user to repeatedly create a chemiluminescent reaction by only mixing a limited portion of the chemiluminescent chemicals contained in the device during a specified period. Likewise, once all the chemical products in the device have been mixed and the chemiluminescent reaction has ceased, a user may empty the device of this liquid and refill the two chambers, separately, with the chemiluminescent chemicals necessary to make further reactions.
The invention can be better understood with reference to the attached drawing, illustrating a representative and nonlimiting embodiment.
FIG. 1 shows a reusable and rechargeable glow device as claimed herein. The glow device, 1 , consists of a translucent outer wall 2 and an substantially parallel inner wall 3 whereby the space between 2 and 3 creates a first chamber which is substantially enclosed by material traversing the space between 2 and 3 on both ends of the chamber as shown by 7 and 14 . A second chamber is found inside the parallel inner wall 3 , which is also substantially enclosed by material traversing the open chamber on both ends, 7 and 14 .
There is also present a first valve, in this embodiment piercing the surface 14 , which first valve allows the introduction of chemiluminescent chemicals into the first chamber, but not into the second chamber. This valve may also allow for the emptying of chemicals from the first chamber. It is also possible that there could be two separate valves attached to the first chamber, but not the second chamber, whereby one allows for the introduction of the chemicals and the second allows for emptying of the chemicals.
In the embodiment shown in FIG. 1 , piercing the surface 14 , there is also present a second valve, which second valve allows for the introduction of chemiluminescent chemicals into the second chamber, but not into the first chamber.
There is further a third valve 11 between the first chamber and second chamber. This third valve only allows a specified amount of chemicals from one of the chambers to proceed to the other chamber, but not return to the original chamber. In this embodiment, this third valve allows chemiluminescent chemicals to flow from the second chamber to the first chamber.
There is also provided a means by which a specified amount of chemicals are forced from the second chamber into the first chamber, through the third valve, which then allows for the mixing of the chemicals causing a chemiluminescent reaction.
In the embodiment of FIG. 1 a knob 4 is attached to a shaft 5 which extends through the surface 7 and into the second chamber continuing lengthwise until it terminates at the other end of the second chamber at surface 14 . The shaft 5 contains spherical splines in the area of the shaft that is contained in the second chamber. A disk 10 , containing mating spherical acceptors, is then attached to the shaft on the spherical splines which allows the disk to the moved lengthwise along the shaft when the shaft is rotated by a turning of knob 4 . A channel 9 , which matches a notch in the disk, ensures that the disk will move lengthwise along the shaft and not merely spin along with the shaft 5 when it is rotated via knob 4 .
There is also provided a hole 8 between the first chamber and second chamber which is blocked by the disk when it is in its first position. This first position is characterized by the fact that no chemiluminescent reaction has taken place and the second chamber is completely filled with the second chemical. Thereafter, a chemiluminescent reaction is obtained by turning knob 4 , which rotates shaft 5 moving disk 10 and thereby introducing a desired amount of the second chemical into the first chemical, which then causes a chemiluminescent reaction.
Due to the fact that the first chamber and the second chamber are closed to ambient air, during the chemiluminescent process, the volume of the second chemical will change as the disk 10 is moved lengthwise along the shaft 5 . In order to ensure that the total volume of liquid in chambers one and two remains constant, hole 8 will allow for the flow of chemicals from the first chamber into the second chamber, in the area above the disk 10 , to maintain a constant total volume and avoid possible failure of the either chamber one or two due to excessive liquid pressure or volume.
Although the present invention has been described in considerable detail with reference to certain preferred versions thereof, other versions are possible. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred versions contained herein.
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The present invention discloses a reusable and rechargeable glow device, whereby the glow device is reused by refilling the device with the necessary chemicals while also being rechargeable between refills through use of a graduated introduction system with regard to the chemicals necessary to provide a chemiluminescent reaction.
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CROSS-REFERENCE TO RELATED APPLICATION
The present application is related to and claims priority from prior provisional application Ser. No. 61/389,352, filed Oct. 4, 2010 which application is incorporated herein by reference.
COPYRIGHT NOTICE
A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever. 37 CFR 1.71(d).
BACKGROUND OF THE INVENTION
The following includes information that may be useful in understanding the present invention(s). It is not an admission that any of the information provided herein is prior art, or material, to the presently described or claimed inventions, or that any publication or document that is specifically or implicitly referenced is prior art.
1. Field of the Invention
The present invention relates generally to the field of hunting and more specifically relates to hunting blinds.
2. Description of the Related Art
Hunting is the practice of pursuing wildlife for food, recreation, or trade. People in modern society practice hunting generally as sport or recreation, but in times of a poor economy, or in areas that are depressed economically, hunting is sometimes practiced more as a supplement to income by reducing the amount of food that would have had to have been bought. In earlier centuries, hunting was practiced to a greater degree to provide a food source for families but the practice gradually declined until the beginning of the 21 st century when only an estimated 6% of Americans hunted. As hunting moved from a subsistence activity to a social one, two trends emerged. One was that of the specialist hunter with special training and equipment. The other was the emergence of hunting as a ‘sport’. The percentage of hunters in American society has increased due to modern sport hunting. Hunting in the United States is not associated with any particular class or culture as it sometimes is in some societies and so a larger percentage of the American population is likely to participate by comparison.
Modern day sport hunting is sophisticated in comparison with the hunting technology of past centuries. Firearms are now considerably more technologically advanced than the firearms of the past century. All-terrain vehicles can easily reach into rough or distant hunting grounds that once were considered virtually inaccessible for most people. Range finders can pinpoint the distance of wild game for archery hunters providing a distinct advantage for the hunter. For such a primitive hunting means, bows and bow accessories nowadays are mostly compound bows with a high degree of built in technology. Bow hunters are sportsmen that take pride in their skill of being able closely approach such wary and quick game as deer, elk, and turkey. Getting close enough to kill these types of game usually takes considerable skill and some hunting knowledge.
Some of the hunting accessories used, such as hunting blinds, are nearly a necessity in many environments where the hunter is unable to approach game within a reasonable distance of a firearm or bow-shot. The modern hunting sport has given rise to many different types of hunter blinds for concealment from animals and fowl. Most of these blind systems utilize a type of camouflaged material that blends with natural surroundings, and some type of framework to support the camouflage material. Blind systems can be either ground blinds or elevated blinds for use in trees or on elevated platforms, but the size and shape of these blinds often don't blend well into the surroundings, nor are they comfortable, nor do they retain body heat well. The majority of these blind systems are not easily transportable, utilize a considerable amount of materials and time to construct, and dictate that the hunter must set up the blind in advance of the hunt and then return to the same location for the hunt. Last minute changes in hunting location are usually not feasible due to the set-up time and level of difficulty to transport a blind system. A blind system is needed that is effective, is comfortable, and yet so lightweight that it is easily transportable while hunting and sets up in seconds.
Various attempts have been made to solve the above-mentioned problems such as those found in U.S. Pat. And Pub. Nos. 7,051,908, 5,617,932, 7,219,680, 2009/0165352, 6,698,131, and 2005/0183758. This prior art is representative of hunting blind systems. None of the above inventions and patents, taken either singly or in combination, is seen to describe the invention as claimed.
Ideally, a hunting blind system should be easy to setup, be readily transportable, and yet would operate reliably and be manufactured at a modest expense. Thus, a need exists for a reliable camouflage hunting blind system to provide transportability and ease of setup, and to avoid the above-mentioned problems.
BRIEF SUMMARY OF THE INVENTION
In view of the foregoing disadvantages inherent in the known hunting blinds art, the present invention provides a novel cocoon hunting hammock system. The general purpose of the present invention, which will be described subsequently in greater detail, is to provide greater portability, comfort, and stealth for the hunter during hunting expeditions.
A camouflage hunting blind system is disclosed herein preferably comprising a hanger with a distal and a proximate end, the distal end of hanger comprising a T-hook. The T-hook preferably comprises two open loops and two closed loops, the proximate end of the hanger comprising an S-hook for suspending a hammock chair which is then cloaked with a camouflaged covering.
To use, a tether such as a rope or a light chain is attached at one end to a tether-hook. The opposite end of the tether is passed through the enclosed eye of the proximate end S-hook of the hanger. The tether hook is passed around a high point on the tree and hooked back to the tether in a choker connection and the distal end of the hanger is positioned against the tree with the proximate end pointing upward and away from the tree at about a 45 degree angle (for stability.) The tether is then passed through a closed loop on the distal end of the hanger and looped over a first open hook on one side of the distal end and passed behind the tree to loop over the second open hook on the distal end of the hanger. The tether is then alternately looped multiple times around the open loops of distal end hanger, passing behind the tree each time, securing the distal end of hanger to the tree.
Next, a hammock (style) chair is removably suspended from the S-hook on the proximate end of the hanger and a camouflage covering is draped about the chair and suspended from the S-hook such that an occupant hunter may be suitably camouflaged during the hunting activity. The vertical post that the present invention is tethered to may comprise a tree but may be any sturdy vertical object of sufficient diameter such as a telephone pole or the like. The hanger preferably comprises ferrous material and is approximately 14″ in length but in certain embodiments may comprise other metals or materials of sufficient strength to support a user or be of varying lengths.
The hammock chair may support a user (hunter or nature-watcher) in a suspended sitting position preferably within proximity to a ground surface such that a user sitting in the hammock chair may touch the ground surface with the user's feet (for safety reasons.) Following approval from future safety testing this product may be used up in a tree stand where the user's feet are in contact with the platform. When the user is sitting in the hammock chair suspended from the S-hook with feet contacting a ground surface, the user may rotate through 360 degrees using his/her feet to view the surroundings getting a complete view of approaching wildlife. In this way the user may be disguised from view (by a wild animal) while sitting comfortably in the hammock chair within the camouflage covering.
In certain embodiments, the camouflage covering may be reversible such that a first side of camouflage covering may be colored with natural surrounding colors and a second side of camouflage covering may be a different camouflage pattern or dark (charcoal or other), and may be made of a waterproof or a water resistant material. The covering is reversible. The camouflage covering is enclosable with a zipper or other suitable fastener system such that a user and hammock chair is disguised within its surroundings, allowing user to be camouflaged in an outdoor environment. The camouflage covering may incorporate a floor and a hood for protection of the hunter from the elements and or insects and zip-down flaps with see-through netting for ease of viewing. The hammock chair may also comprise camouflage on a first side and hunter orange on the second side and it is reversible. The hammock chair and hanger may be used for various activities while camping, viewing sporting events, sitting on a boat dock, a back porch or the like. The camouflage hunting blind system is easily portable and comprises a carrying case with a strap and a drawstring.
The camouflage hunting blind system may further comprise a kit for use in hunting and/or nature-watching having: at least one hanger; at least one tether; at least one tether-hook; at least one hammock chair; at least one camouflage covering; and a set of user instructions.
A method of use for a camouflage hunting blind system may comprise the steps of: positioning the distal end of the hanger against a pole with the proximate end at about a 45 degree upward angle (relative the post/tree it is attached to); fastening the distal end of the hanger to the pole/tree with the tether; looping the tether around the pole at a high point; hooking the tether-hook to the S-hook on the hanger at the proximate end of the hanger; adjusting tether to remove slack and securing it at the upward 45 degree angle pointing away from the tree or post; hanging a camouflage covering from the S-hook at the proximate end of the hanger; hanging a hammock chair from the S-hook within camouflage covering; and using camouflaged hunting blind system for observing wild animals.
The present invention holds significant improvements and serves as a camouflage hunting blind system. For purposes of summarizing the invention, certain aspects, advantages, and novel features of the invention have been described herein. It is to be understood that not necessarily all such advantages may be achieved in accordance with any one particular embodiment of the invention. Thus, the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other advantages as may be taught or suggested herein. The features of the invention which are believed to be novel are particularly pointed out and distinctly claimed in the concluding portion of the specification. These and other features, aspects, and advantages of the present invention will become better understood with reference to the following drawings and detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
The figures which accompany the written portion of this specification illustrate embodiments and method(s) of use for the present invention, cocoon hunting hammock systems, constructed and operative according to the teachings of the present invention.
FIG. 1 shows a perspective view illustrating a cocoon hunting hammock system with a camouflage covering in an in-use condition according to an embodiment of the present invention.
FIG. 2 is a perspective view illustrating a hanger of the cocoon hunting hammock system according to an embodiment of the present invention of FIG. 1 .
FIG. 3 is a perspective view illustrating the cocoon hunting hammock system hammock chair and camouflage covering in another in-use condition pose according to an embodiment of the present invention of FIG. 1 .
FIG. 4 is a perspective view illustrating the hanger of the cocoon hunting hammock system as fastened to a tree (or vertical post) according to an embodiment of the present invention of FIG. 1 .
FIG. 5 is a flowchart illustrating a method of use for the cocoon hunting hammock system according to an embodiment of the present invention of FIGS. 1-4 .
The various embodiments of the present invention will hereinafter be described in conjunction with the appended drawings, wherein like designations denote like elements.
DETAILED DESCRIPTION
As discussed above, embodiments of the present invention relate to a hunting blind and more particularly to a camouflage hunting blind system as used to improve the portability, comfort, and convenience of packing and setting up a hunting blind system.
Referring to the drawings by numerals of reference there is shown in FIG. 1 , is a perspective view illustrating an in-use condition of cocoon hunting hammock system 100 with camouflage covering 170 according to a preferred embodiment of the present invention. Cocoon hunting hammock system 100 is shown as suspended from main trunk of a tree (vertical post 180 ) in this FIG. 1 and shown as suspended from a strong branch of the tree (vertical post 180 ) in this FIG. 3 showing its versatility of use.
In this particular embodiment shown (also referencing FIGS. 2 and 4 , camouflage hunting blind system 102 may comprise hanger 120 with distal end 122 and proximate end 124 ; with end of hanger 120 comprising T-hook 126 and with T-hook 126 comprising two open loop(s) 128 and two closed loop(s) 130 . Proximate end 124 of hanger 120 preferably comprises S-hook 132 (as shown in FIGS. 2 and 4 ).
Referring now back to FIGS. 1 and 3 , tether 140 or other suitable attaching means comprises first end 142 and second end 144 . Tether-hook 150 may be attached to first end 142 of tether 140 , hammock chair assembly 160 , and camouflage covering 170 . Hanger 120 is removably attachable to vertical post 180 , as shown, with (using) tether 140 in the following way: first end 142 of tether 140 with tether-hook 150 attaches about vertical post 180 and back to tether 140 in choker fashion, second end 144 passes through closed loop(s) 130 on S-hook 132 at proximate end 124 of hanger 120 and then through one closed loop(s) 130 on distal end 122 of hanger 120 . Distal end 122 of hanger 120 is then restable against vertical post 180 and removably affixed using tether 140 , with proximate end 124 of hanger 120 extending upwardly and outwardly from vertical post 180 at about a 45 degree agree relative to vertical post 180 . In this way (and others the present invention may be secured to vertical post 180 for use).
At least one hammock chair assembly 160 is then removably hooked onto S-hook 132 of proximate end 124 of hanger 120 and camouflage covering 170 is suspended from S-hook 132 and draped about hammock chair assembly 160 such that the user residing within hammock chair assembly 160 is disguised within its surroundings. Camouflage hunting blind system 102 is easily portable and may be set up in less than two minutes (for experienced users.) Camouflage hunting blind system 102 in the embodiment shown weighs less than 10 pounds and rolls up tightly to be placed inside of a carrying case with at least one but preferably two carrying straps and a drawstring. In this way the present invention is portable and easy to use. Hanger 120 may also comprise different shapes and configurations and is of suitable design and durability to hold at least one user safely during the hunting/watching activity.
Referring now to FIG. 2 , a perspective view illustrating hanger 120 of cocoon hunting hammock system 100 according to an embodiment of the present invention of FIG. 1 .
Hanger 120 may be attached to a (substantially circular) vertical post 180 of a diameter within a given range. Vertical post 180 preferably comprises a tree 182 that may be used during a hunting period (since trees 182 are normally found within the wildlife's natural environment.) Hanger 120 , as used, may comprise a ferrous material or a non-ferrous material of sufficient strength to support at least 250 pounds (at least the weight of an average man and the hung equipment.) Hanger 120 is approximately 14″ in length, sufficient to suspend camouflage hunting blind system 102 away from tree 182 enough to rotate hammock chair assembly 160 about 360 degrees for a full field of vision. When cocoon hunting hammock system 100 (may comprise hammock chair/boslom chair; wherein hammock chair may comprise boslom chair) is suspended from an overhead horizontal branch (as in FIG. 3 ), a full 360 degree rotation and field of view is achievable. When camouflage hunting blind system 102 is suspended from a horizontal branch, hanger 120 is utilized in a substantially vertical position still leaving S-hook 132 at an angle such that hammock chair assembly 160 and camouflage covering 170 may be safely suspended (and rotated.)
Referring now again more specifically to FIG. 3 , a perspective view illustrating cocoon hunting hammock system 100 hammock chair assembly 160 , and camouflage covering 170 according to an embodiment of the present invention of FIG. 1 . Hammock chair assembly 160 may support a user in a suspended position from vertical post 180 or tree 182 . When in use by a hunter and/or nature-watcher sitting in hammock chair assembly 160 , the hunter and/or nature-watcher may be disguised within camouflage covering 170 from view by an animal. As previously mentioned for safety reasons, camouflage hunting blind system 102 is for use within reasonable proximity to a ground surface, such that user sitting in hammock chair assembly 160 can touch a ground surface.
When hammock chair assembly 160 is hanging on S-hook 132 , it is rotatable through 360 degrees in this particular hanging orientation. Camouflage covering 170 may be reversible such that a first side of camouflage covering 170 is colored with natural surrounding colors and a second side of camouflage covering 170 may be a dark charcoal or black color or may be a second camouflage pattern so that a user may the place the preferable pattern toward the outside for greater concealment from game. Camouflage covering 170 is preferably water resistant (or substantially waterproof) and is able to keep a user at a warmer temperature than surrounding ambient temperature as well as provide containment of human scent. Camouflage covering 170 is encloseable with fastener 190 such that the user may be disguised to a user-preferred amount/degree. Fastener 190 may comprise a zipper 195 for ease of use or other suitable equivalent. Camouflage covering 170 may comprise (see-through) netting with zip-down flaps. Camouflage covering 170 may comprise a floor as protection from insects and reptiles as well as to provide greater covering as an isolation means from cold ground temperatures and may comprise zip down flaps exposing see-through netting for greater viewing. Camouflage covering 170 may also comprise a hood 172 for covering the user from rain or as a shading device from the sun. In certain embodiments a circulating fan may be included to remove CO 2 , scent or other (may use activated charcoal or the like.)
Referring now to FIG. 4 a perspective view illustrating the cocoon hunting hammock system 100 hanger 120 as fastened to a tree 182 according to an embodiment of the present invention of FIG. 1 .
Distal end 122 of hanger 120 is restable against vertical post 180 and removably affixed using tether 140 , with proximate end 124 of hanger 120 extending upwardly and outwardly from vertical post 180 or tree 182 at approximately a 45 degree angle. Tether-hook 150 is passed around a high point on tree 182 and hooked back to the tether 140 in a choker connection and distal end 122 of hanger 120 is positioned against tree 182 with proximate end 124 pointing upward and away from tree 182 at about a 45 degree angle. Tether 140 is then passed through closed loop(s) 130 on the distal end 122 of hanger 120 and looped over a first open hook on one side of distal end 122 and passed behind the tree 182 to loop over the second open hook on distal end 122 of the hanger 120 . Tether 140 is alternately looped multiple times around open loops of distal end 122 , passing behind the tree 182 each time, securing distal end 122 of hanger 120 to tree 182 . It should be appreciated that the fastening system and means is not intended to be limited to that which is described herein, but rather that other equivalent tying means may be employed and still be considered to be within the scope of the present invention, that the means disclosed is by way of enablement such that the present invention may be used in one safe manner (of many.)
Cocoon hunting hammock system 100 may be sold as kit 440 comprising the following parts: at least one hanger 120 at least one tether 140 ; at least one tether-hook 150 ; at least one hammock chair assembly 160 ; at least one camouflage covering 170 ; and at least one set of user instructions. Cocoon Hunting Hammock System 100 may be manufactured and provided for sale in a wide variety of sizes and shapes for a wide assortment of applications. Upon reading this specification, it should be appreciated that, under appropriate circumstances, considering such issues as design preference, user preferences, marketing preferences, cost, structural requirements, available materials, technological advances, etc., other kit contents or arrangements such as, for example, including more or less components, customized parts, different color combinations, parts may be sold separately, etc., may be sufficient.
Referring now to FIG. 5 , showing a flowchart illustrating a method of use 500 for cocoon hunting hammock system 100 according to an embodiment of the present invention of FIGS. 1-4 .
Method of use 500 for cocoon hunting hammock 100 system may comprise the steps of: steps one 501 —step one 507 starting with step one 501 looping a first end of tether 140 with tether-hook 150 around a vertical post 180 at a high point and hooking tether-hook 150 back to tether 140 using a choker connection; step two 502 passing a second end 144 of tether 140 , first through closed loop(s) 130 of S-hook 132 on proximate end 124 of hanger 120 and then through closed loop(s) 130 on a distal end 122 of hanger 120 ; step three 503 positioning distal end 122 of hanger 120 against vertical post 180 with proximate end 124 at about a 45 degree upward angle pointing away from vertical post 180 ; step four 504 fastening distal end 122 of hanger 120 to vertical post 180 with tether 140 using open loop(s) 128 on distal end 122 of hanger 120 ; step five 505 hanging a camouflage covering 170 from S-hook 132 from proximate end 124 of hanger 120 ; step six 506 hanging hammock chair assembly 160 from S-hook 132 within camouflage covering 170 ; and step seven 507 using cocoon hunting hammock system 100 as an animal watching or camouflage hunting blind system 102 . It should be noted that steps 505 and 507 are optional steps and may not be implemented in all cases.
It should be noted that the steps described in the method of use can be carried out in many different orders according to user preference. Upon reading this specification, it should be appreciated that, under appropriate circumstances, considering such issues as design preference, user preferences, marketing preferences, cost, structural requirements, available materials, technological advances, etc., other methods of use arrangements such as, for example, different orders within above-mentioned list, elimination or addition of certain steps, including or excluding certain maintenance steps, etc., may be sufficient.
The embodiments of the invention described herein are exemplary and numerous modifications, variations and rearrangements can be readily envisioned to achieve substantially equivalent results, all of which are intended to be embraced within the spirit and scope of the invention. Further, the purpose of the foregoing abstract is to enable the U.S. Patent and Trademark Office and the public generally, and especially the scientist, engineers and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application.
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A camouflage hunting blind system comprising a hanger with a distal and a proximate end, the proximate end of the hanger comprises an S-hook for suspending a hammock chair which is then cloaked within a camouflaged covering. The distal end of the hanger is positioned against tree with the proximate end pointing upward and away from the tree at a 45 degree angle wherein both ends are secured using a tether. The camouflage hunting blind system is positioned so a user's feet may touch the ground to rotate hammock chair for (through) 360 degrees of view. The hammock chair may be reversible, having a first side with natural (nature camouflage) colorings and a second side with hunter orange or other suitable coloring (dark or other.) Camouflage hunting blind system may have a camouflage coloring on the outside and a dark coloring on the inside, and weigh less that 10 lbs, and sets up in a very short time. Camouflaged covering encapsulates hammock chair, concealing scent and providing warmth for its user(s).
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CROSS-REFERENCE TO RELATED COPENDING PATENT APPLICATIONS
[0001] The following patent applications, which are assigned to the assignee of the present invention and filed concurrently herewith, cover subject matter related to the subject matter of the present invention and are incorporated herein by reference:
[0002] Serial Number Title
[0003] Cradle For A Quick Barrel Change.
[0004] Force Isolating Cradle Assembly.
[0005] Injection Unit
BACKGROUND OF THE INVENTION
[0006] 1. Field of the Invention
[0007] The present invention broadly relates to injection molding machines and, in particular to the injection unit of an injection molding machine. Injection molding machines include machines for injecting plastic material, or metal material, or metal material in a thixotropic state.
[0008] 2. Summary of the Prior Art
[0009] Operation of an injection molding machine introduces a number of forces, pressures, and stresses on the injection unit. For example, axial carriage force is a force applied to engage the nozzle end of a barrel assembly against a sprue bushing of a mold. This provides a force sealing connection between the nozzle and sprue bushing preventing leakage of melted material during injection. Carriage force is applied and maintained prior to injecting the melt of material.
[0010] Injection force is a force directed along the length of a reciprocating screw located in a bore of a barrel assembly. Injection force results in injecting a melt of material into a mold. There is an axial reactive injection force acting along the length of the barrel assembly as a result of moving a screw forward during the injection stage of a molding process.
[0011] Injection pressure is a pressure required to overcome the resistance to the flow of the melt of material in the nozzle, runner system, and mold cavity. Injection pressure is exerted on the melt in front of the screw tip during the injection stage of a molding process. The accumulator end of a barrel assembly must withstand injection pressure.
[0012] Injection units for molding machines are very well known. For example, the book entitled “Injection Molding machines A User's Guide 3 rd Edition” by Johannaber was published in 1994 by Carl Hanser Verlag (ISBN 1-56990-169-4) and contains a detailed description of conventional injection units for plastic injection molding machines in Chapter 3 on pages 38, 39 42, 43, 44, 75, and 76. The reciprocating screw (RS) injection unit includes a barrel assembly which includes a nozzle, barrel head, barrel, axial bore, feed port, heater bands, and thermocouples. A reciprocating screw, which includes a non-return valve, is disposed in the axial bore of the barrel. The axial bore of the barrel includes a metering section and a feeding section. An electric or hydraulic drive operates the screw to feed and meter a melt of material and inject the metered material into a mold. The barrel assembly is fixed and supported, cantilevered, at one end of the barrel by a carriage. Hydraulic or electric actuators connect between the carriage and a frame member or fixed platen of the injection molding system. Operation of the actuators move the barrel assembly towards and away from the stationary platen and provides an axial carriage force through the entire length of the barrel during injection minimizing leakage between the nozzle tip and the sprue bushing. The axial reactive injection force is directed through the entire length of the barrel during injection.
[0013] The book entitled “Injection Molding Operations” produced by Husky Injection Molding Systems Ltd., and printed in Canada, copyright 1980 also contains a description of conventional injection units for plastic injection molding machines on pages 41 through 44. Again, for the reciprocating screw injection unit, a barrel is supported at a distant end by a carriage, which houses the injection cylinder and a rotational drive. A hydraulic cylinder is connected between the carriage and a stationary platen. In operation of the hydraulic cylinder, the carriage force is applied along the entire length of the barrel. For a two stage injection unit, a barrel is supported at one end by a carriage. The carriage houses the drive. The nozzle of the barrel feeds into a shooting pot which includes an injection piston. The carriage supports another end of the shooting pot. A hydraulic cylinder is connected between the carriage and a stationary platen. In operation of the hydraulic cylinder, the carriage force is applied along the entire length of the shooting pot. The axial reactive injection force is directed through the entire length of the shooting pot during injection.
[0014] U.S. Pat. No. 5,040,589 issued on Aug. 20, 1991 to Bradley et al (assigned to The Dow Chemical Company). The patent describes an injection apparatus for injection molding a thixotropic semi-solid metal alloy. The patent contains a description of an apparatus for processing a metal feedstock into a thixotropic state as the metal is fed into a hopper, located at one end of the barrel, and transported into an accumulation zone located at another end of the barrel. The barrel is constructed of a single piece of material with thick walls. A number of heating zones are defined along the length of the barrel, including sections of the barrel having differing thickness. The feed throat area and zone 4 are relatively thick sections. Zone 3 is a slightly thinner section, and zone 2 is the thinnest section. The barrel is conventionally mounted in the injection unit. A feed throat end of the barrel is mounted in an upright support secured to the frame of an injection unit. A bottom surface of the barrel, intermediate the distant ends of the barrel, rests on a second support also secured to the frame. The carriage force is applied along the entire length of the barrel in operation of the apparatus. All sections of the disclosed barrel must be thick enough to withstand the combination of axial carriage force and axial reactive injection force directed through the entire length of the barrel during injection.
[0015] U.S. Pat. No. 5,983,978 issued on Nov. 16, 1999 to Vining et al (assigned to Thixomat Inc.). The patent describes a thixotropic metal injection molding apparatus. The barrel is formed in two sections to define a high pressure section and a low pressure section. The low pressure section is thinner than the high pressure section. A feed throat end of the barrel is mounted in an upright support of an injection unit. A bottom surface of the barrel, intermediate the distant ends of the barrel, rests on a second support also secured to the frame. The carriage force is applied along the entire length of the barrel in operation of the apparatus. All sections of the disclosed barrel must be thick enough to withstand the combination of axial carriage force and reactive injection force through the entire length of the barrel during injection.
[0016] There are a number of problems and deficiencies with the known prior art devices. Barrels are costly due to the amount of material required to provide a suitable thickness for withstanding the axial force along the entire length of the barrel. The axial force may be the carriage force, or the reactive injection force, or a combination of these two forces.
[0017] Special materials are required for barrels in use with thixotropic materials and these special materials are very expensive and are difficult to manufacture.
[0018] Thick barrels have a high thermal resistance which affects the efficiency and controllability of heating a material in the axial bore of a barrel.
[0019] Barrels, conventionally mounted in the injection unit, are typically difficult to install and remove. The process of installation and removal within a carriage is time consuming. Installation of the barrel in a carriage is further prone to alignment problems.
SUMMARY OF THE INVENTION
[0020] The primary objective of the present invention is to provide an improved barrel assembly for use in an injection molding machine.
[0021] Another primary objective of the present invention is to provide an improved carriage assembly for use in an injection molding machine.
[0022] Another primary objective of the present invention is to provide an improved injection unit for use in an injection molding machine.
[0023] Another primary objective of the present invention is to isolate a portion of a barrel assembly from axial forces.
[0024] Another object of the present invention is to reduce the cost of a barrel assembly.
[0025] Another object of the present invention is to reduce the amount of material required in certain sections of a barrel assembly.
[0026] Another object of the present invention is to reduce the weight of a barrel assembly.
[0027] Another object of the present invention is to reduce the axial stress in a portion of the barrel assembly.
[0028] Another object of the present invention is to reduce the thermal mass in a portion of the barrel assembly.
[0029] Another object of the present invention is to couple and support the barrel intermediate the ends of the barrel for providing more accurate alignment of a nozzle to the sprue bushing.
[0030] Another object of the present invention is to provide a carriage assembly permitting unobstructed access for installing and removing the barrel assembly.
[0031] Another object of the present invention is to provide a carriage assembly with a first coupler for securing the barrel assembly intermediate the ends of the barrel assembly to the cradle assembly.
[0032] Another object of the present invention is to provide a carriage assembly with a second coupler for retaining a portion of the barrel assembly to the cradle assembly.
[0033] Another object of the present invention is to provide a carriage assembly with a barrel support for aligning the barrel within the carriage assembly during installation of the barrel assembly with the carriage assembly.
[0034] The foregoing objects are achieved by providing a barrel assembly for use in an injection molding machine. The barrel assembly consists of a barrel and a first coupler. The barrel having a first portion, a discharge end, and an opening. The barrel having a lengthwise axial bore extending between said discharge end and said opening for receiving a reciprocating screw. The first coupler is disposed on the first portion of the barrel wherein the first coupler isolates a second portion of the barrel from an axial force.
[0035] As an alternative, the first barrel coupler may include a linkage member. The first barrel coupler may include a second linkage member. The linkage member may include a thermal isolator. In an embodiment of the invention, the linkage member is a pair of standoffs. In another embodiment of the invention, the second linkage member is a ring.
[0036] As an alternative, the barrel assembly may include a second coupler disposed on the second portion of the barrel. The second coupler is adapted to cooperate with the second portion of the barrel and a second carriage coupler to permit axial movement of the barrel and prevent rotational movement of the barrel.
[0037] As an alternative, the barrel assembly may include an axial force linkage member disposed on the first coupler. The axial force linkage member distributes the axial force.
[0038] As an alternative, the barrel assembly may include a thermal insulator disposed on the first coupler. The thermal insulator reduces conductive heat transfer between the barrel assembly and a carriage.
[0039] As an alternative, the barrel assembly may include a linkage insulator disposed on the first coupler. The linkage insulator distributes the axial carriage force and reduces conductive heat transfer between the barrel assembly and the carriage. In an embodiment of the invention, the linkage insulator is an axial force linkage member and thermal insulator.
[0040] As an alternative, the barrel assembly may include a plurality of second couplers. In one embodiment of the invention, the second coupler is a recess formed in an outer surface of the second portion of the barrel. In another embodiment of the invention, the recess is a substantially flat pad. In another embodiment of the invention, the recess forms a spline. In another embodiment of the invention, the recess is an axially aligned slot.
[0041] As an alternative, the barrel assembly may include a plurality of axial force linkage members. In an embodiment of the invention, the axial force linkage member is of unitary construction formed on a surface of the first coupler. In another embodiment of the invention, the axial force linkage member is retained on the first coupler.
[0042] As an alternative, the barrel assembly may include a plurality of thermal insulators. In an embodiment of the invention, the thermal insulator is of unitary construction formed on the first coupler. In another embodiment of the invention, the thermal insulator is retained to the first coupler.
[0043] As an alternative, the barrel assembly may include a plurality of linkage insulators. In an embodiment of the invention, the linkage insulator is of unitary construction formed on a side of the first coupler. In another embodiment of the invention, the linkage insulator is retained to the first coupler.
[0044] As an alternative, the barrel assembly may include a barrel liner retained in the axial bore to isolate and protect the barrel from the melt of material.
[0045] The barrel assembly may be of unitary construction. Alternatively, the barrel assembly may be a plurality of barrel sections secured together. For the case wherein the barrel assembly is a plurality of barrel sections, each barrel section may further include a seal preventing leakage of a melt of material.
[0046] Further objects and advantages of the present invention will appear hereinbelow.
BRIEF DESCRIPTION OF THE DRAWINGS
[0047] Embodiments of the present invention will now be described, by way of example only, with reference to the attached figures, wherein
[0048] [0048]FIG. 1 is a diagrammatic side view representation of an injection molding machine illustrating a clamp unit interconnected to an injection unit;
[0049] [0049]FIG. 2 is a perspective view of an injection assembly;
[0050] [0050]FIG. 3 is an exploded perspective view of the injection assembly illustrating a barrel assembly and a carriage assembly;
[0051] [0051]FIG. 4 is a cross sectional view taken along line AA from FIG. 2 illustrating a multi-piece barrel assembly located in the carriage assembly;
[0052] [0052]FIG. 5 is a cross sectional view taken along line AA from FIG. 2 illustrating a nozzle section with a spigot tip;
[0053] [0053]FIG. 6 is a cross sectional view taken along line AA from FIG. 2 illustrating an alternative nozzle section with a semispherical tip;
[0054] [0054]FIG. 7 is a perspective view illustrating an accumulator section of the barrel assembly and a first barrel coupler;
[0055] [0055]FIG. 8 is a cross sectional view taken along line AA from FIG. 2 illustrating an accumulator section of the barrel assembly and a first barrel coupler;
[0056] [0056]FIG. 9 is a cross sectional view taken along line AA from FIG. 2 illustrating a second portion of the barrel assembly;
[0057] [0057]FIG. 10 is a partial perspective view of a second portion of the barrel assembly illustrating a second barrel coupler;
[0058] [0058]FIG. 11 is a top view of cradle member;
[0059] [0059]FIG. 12 is a cross sectional side view of the cradle member taken along line C-C of FIG. 11 illustrating the first cradle coupler, the second carriage coupler, the first barrel support member, and the second barrel support member;
[0060] [0060]FIG. 13 is a front view of the cradle member illustrating the first cradle coupler and the first barrel support member;
[0061] [0061]FIG. 14 is an end view of the cradle member illustrating the drive mount;
[0062] [0062]FIG. 15 is a front view of the yoke;
[0063] [0063]FIG. 16 is a back view of the yoke;
[0064] [0064]FIG. 17 is a cross sectional side view of the yoke taken along line D-D of FIG. 16;
[0065] [0065]FIG. 18 is a partial perspective view of the barrel assembly and carriage assembly illustrating installation of the barrel assembly within the carriage assembly;
[0066] [0066]FIG. 19 is a partial perspective view of the barrel assembly and carriage assembly illustrating the barrel assembly installed in the carriage assembly;
[0067] [0067]FIG. 20 is a top view of the carriage illustrating the relationship between the second barrel coupler and the second cradle coupler;
[0068] [0068]FIG. 21 is a partial top cross sectional view taken along line BB of FIG. 2 illustrating the relationship between the first barrel coupler and the first carriage coupler with a spigot tip nozzle for axial carriage force;
[0069] [0069]FIG. 22 is a top cross sectional view taken along line BB of FIG. 2 illustrating the relationship between the barrel assembly with a spigot tip nozzle and the carriage assembly for axial reactive injection force;
[0070] [0070]FIG. 23 is a partial top cross sectional view taken along line BB of FIG. 2 illustrating the relationship between the first barrel coupler and the first carriage coupler with a semispherical tip nozzle for axial carriage force;
[0071] [0071]FIG. 24 is a top cross sectional view taken along line BB of FIG. 2 illustrating the relationship between the barrel assembly with a semispherical tip nozzle and the carriage assembly for axial reactive injection force;
[0072] [0072]FIG. 25 is a cross sectional view taken along line AA of FIG. 2 illustrating a screw located in the barrel assembly in a first operative position; and FIG. 26 is a cross sectional view taken along line AA of FIG. 2 illustrating a screw located in the barrel assembly in a second operative position.
Nomenclature List 10 Injection molding machine. 12 Clamp unit. 14 Injection unit. 16 Stationary platen. 18 Clamp frame member. 20 Moving platen. 22 Actuator. 24 Moving half of a mold. 26 Stationary half of a mold. 27 Injection assembly. 28 Injection unit frame. 30 Barrel assembly. 32 Tie bars. 34 Carriage assembly. 36 Drive assembly. 38 Screw translation drive. 40 Screw rotation drive 42 Carriage actuator. 44 First barrel portion. 46 First barrel coupler. 48 Second barrel portion. 50 Yoke. 51 Opening 52 Cradle member. 53 Opening 54 Drive mount. 55 Opening. 56 First carriage actuator. 57 Opening. 58 Second carriage actuator. 60 Second barrel coupler. 62 Nozzle. 64 Accumulator. 66 Sealing joint. 68 Sealing joint. 70 Elongate section. 72 Mounting flange. 74 Bores. 76 Accumulator end. 78 Spigot. 80 First diameter axial bore. 82 First concentrator. 84 Second diameter axial bore of a nozzle. 86 Mold end. 88 Spigot tip. 90 Semispherical tip. 92 Opening. 94 Opening. 96 Axial force linkage member. 98 Thermal isolator. 99 Linkage insulator. 100 Bore. 102 Threaded bores. 104 Elongate section. 108 Threaded bores. 110 Second Concentrator. 112 First accumulator diameter bore. 114 Bore. 116 Second diameter bore. 118 End wall. 120 First end wall. 122 Bore. 124 Second end wall. 126 Side. 128 Cylindrical connector. 130 Flange. 132 Bores. 134 Second opening. 136 Second end wall. 138 Liner. 140 Feed throat. 142 Outer barrel. 146 First opening. 147 Axial bore. 148 Second carriage coupler. 150 Second axial force linkage member. 152 First carriage coupler. 153 Engagement member. 155 Support surface. 156 First carriage stop. 158 Second carriage stop. 160 Screw tip. 162 Check valve. 164 Reciprocating screw body. 170 First carriage actuator housing. 172 Second carriage actuator housing. 174 First end. 176 Lengthwise axial opening. 178 First cradle coupler. 180 Support Web. 182 Upper carriage member. 134 Lower carriage member. 186 Support web. 188 Upper carriage member. 190 Lower carriage member. 192 Upright wall member. 194 Upright wall member. 196 First support. 198 First coupler member. 200 Second coupler member. 202 First coupling surface. 204 Second coupling surface. 206 Second support 208 First coupling member. 210 Second coupling member. 212 First coupling surface. 214 second coupling surface. 216 Support Gussets. 218 First barrel support member. 220 Second barrel support member. 222 First upright standoff. 224 Second upright standoff. 226 First upright standoff. 228 Second upright standoff. 230 Yoke mounting surface. 232 Barrel first coupler opening. 234 Mounting surface. 236 Threaded bores 238 Opening 240 Front face. 242 Back side. 244 Left side. 246 Right side. 248 Opening. 250 Central axial bore. 252 Barrel seat. 254 First yoke support. 256 Supporting surface. 258 Second yoke support. 260 Supporting surface. 262 Retaining plate.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0073] An embodiment of the invention is initially described referring to FIG. 1, which illustrates an injection molding machine, generally indicated at 10 . The injection molding machine includes a clamp unit, indicated at 12 , interconnected and secured to an injection unit, indicated at 14 .
[0074] A stationary platen 16 is fixed to a clamp frame member 18 of the clamp unit 12 . A moving platen 20 is operable between an open position and a closed position through an actuator 22 . Those skilled in the art appreciate that the actuator 22 may be either hydraulic, electric, or a combination of hydraulic and electric actuators. A plurality of tie bars 32 extend between the stationary platen 16 and the actuator 22 . A moving half of a mold 24 is mounted on a face of the moving platen 20 and a stationary half of a mold 26 is mounted on a face of the stationary platen 16 .
[0075] The clamp unit 12 of FIG. 1 is a two platen clamp. Alternatively, the clamp unit 12 may be a multi-station clamp unit, for example a stack mold carrier, having more than one moving platen and more than one mold. Alternatively, the clamp unit 12 may be an index clamp unit having a rotating multi-face turret block in place of a moving platen. Alternatively, the clamp unit 12 may be a tandem clamp unit having two molds operated in sequence.
[0076] An injection assembly 27 is mounted on a injection unit frame 28 of the injection unit 14 . The frame 28 typically houses the control system, electronics, and power pack. The injection assembly 27 further includes a barrel assembly 30 , a carriage assembly 34 for supporting and securing the barrel assembly 30 , and a drive assembly 36 . The drive rotates a screw to create a melt of material and feed the material forward in the barrel into an accumulation zone. The drive also reciprocates the screw to inject the melt of material into the mold.
[0077] Referring now to FIG. 1 and FIG. 2, the drive assembly 36 is further described. In an embodiment of the invention, the drive assembly includes both hydraulic and electric components. A screw translation drive 38 provides axial movement of the screw (not shown) in the barrel assembly 30 . A screw rotation drive 40 rotates the screw (not shown) within the barrel assembly 30 . The screw translation drive 38 is hydraulic and the screw rotation drive 40 is electric. Alternatively, the drive could be completely hydraulic or completely electric. Activation of the translation drive 38 axially reciprocates the screw without rotation of the screw by the screw rotation drive 40 .
[0078] The barrel assembly 30 is mounted and securely retained within the carriage assembly 34 . The carriage actuator 42 extends between the carriage assembly 34 and the stationary platen (see FIG. 1). Operation of the carriage actuator 42 moves the injection assembly 27 towards and away from the stationary platen for locating the end of a nozzle into contact with a sprue bushing.
[0079] Referring now to FIG. 3, the injection assembly 27 is further described. The carriage assembly 34 includes a cradle member 52 , a yoke 50 , and a drive mount 54 for mounting the drive assembly 36 (see FIGS. 1 and 2).
[0080] The barrel assembly 30 includes a first barrel portion 44 , a first barrel coupler 46 , a second barrel portion 48 , and a second barrel coupler 60 . The first barrel coupler 46 is disposed on the barrel assembly 30 and interlocks with first carriage coupler to secure the barrel assembly 30 in the carriage assembly 34 . The first carriage coupler is formed intermediate the yoke 50 and an end of the cradle member 52 to be described later.
[0081] The location of the first barrel coupler 46 defines a first barrel portion 44 and a second barrel portion 48 of the barrel assembly 30 . The first barrel portion 44 is a section of the barrel that is capable of withstanding injection pressure. The second barrel portion 48 is a section of the barrel that is isolated from axial forces, both the axial carriage force and the axial reactive injection force.
[0082] The second coupler 60 is disposed on the second barrel portion 48 and communicates with a second carriage coupler located at another end of the cradle member 52 , near the drive mount 54 , retaining the second portion 48 of the barrel assembly 30 in the cradle assembly 34 . Alternatively the second coupler 60 may be disposed between the first barrel coupler 46 and an end of the second barrel portion 48 .
[0083] The carriage actuator 42 includes a pair of hydraulic actuators indicated as 56 and 58 . One end of the first carriage actuator 56 connects to one side of the carriage assembly 34 through a conventional fastener such as a pin (not shown) through the openings 51 and 53 . The other end of the first carriage actuator 56 connects to the stationary platen (see FIG. 1). One end of the second carriage actuator 56 connects to a second side of the carriage assembly 34 through another conventional fastener such as a pin (not shown) through the openings 55 and 57 . The other end of the second carriage actuator 58 connects to the stationary platen (not shown).
[0084] Referring now to FIG. 4, a cross sectional view of the barrel assembly 30 is now further described. The barrel assembly 30 is shown mounted within the carriage assembly 34 . The barrel assembly 34 includes the first barrel portion 44 and the second barrel portion 48 . The first barrel coupler 46 is disposed on the barrel assembly 30 and defines the boundary between the first barrel portion and the second barrel portion. The second barrel coupler 60 is disposed at an end on the second barrel portion 48 . In this embodiment, the first barrel coupler 46 is integrally formed on the first barrel section 44 and the second barrel coupler 60 is formed onto the outer surface of the second barrel portion 48 .
[0085] The first barrel portion 44 includes a nozzle 62 and an accumulator 64 . The nozzle 62 is mechanically secured by a plurality of fasteners to an end of the accumulator 64 . The nozzle 62 seals at the joint 66 with the end of the accumulator 64 preventing leakage of melted material. An axial bore of the nozzle 62 aligns with an axial bore of the accumulator 64 permitting a flow of melt during injection. Alternatively, the nozzle 62 is of unitary construction with the barrel assembly 30 .
[0086] The second barrel portion 48 is a feed section and is mechanically secured by a plurality of fasteners to another end of the accumulator 64 . The second barrel portion 48 seals at the joint 68 at the other end of the accumulator 64 . An axial bore of the second barrel portion 48 aligns with the axial bore of the accumulator permitting a flow of melt from the second barrel section 48 to the accumulator 64 . In an alternative embodiment of the invention, the first barrel section 44 and the second barrel section 48 are of unitary construction without the joints 66 and 68 .
[0087] Referring now to FIGS. 5 and 6, two embodiments of a nozzle 62 are described. The nozzle 62 has an elongate cylindrical section 70 extending from a mounting flange 72 to a mold end 86 of the nozzle 62 . The mounting flange 72 is cylindrical and formed integral to the elongate cylindrical section 70 . The mounting flange 72 has a diameter greater than the elongate section 70 . The mounting flange 72 includes a plurality of spaced apart bores 74 for receiving mounting bolts (not shown) . The accumulator end 76 of the nozzle 62 includes a spigot seal 78 . The spigot seal 78 is cylindrical and extends outwardly from a side of the flange 72 . The nozzle 62 includes a melt channel made up of a first diameter axial bore 80 , a first concentrator 82 , and a second diameter axial bore 84 . In operation during injection, the melt channel receives the melt from the accumulator through the opening 92 . The melt travels along the melt channel in the nozzle 62 and exits the nozzle at another opening 94 en route to a mold.
[0088] In a first embodiment of the nozzle 62 , the mold end 86 includes a spigot tip 88 . The spigot tip 88 is cylindrical and extends into a complimentary cylindrical bore in a sprue bushing (not shown) for tight sealing engagement between the mold end 86 of the nozzle 64 and the sprue bushing during injection of a melt of material. In operation, the spigot tip 88 is in sliding sealing engagement with the complimentary cylindrical bore in the sprue bushing. The spigot tip 88 is permitted to move with respect to the sprue bushing.
[0089] In a second embodiment of the nozzle 62 , the mold end 86 includes a convex semispherical tip 90 . The semispherical tip 90 engages a complimentary concave semispherical opening in a sprue bushing (not shown) for tight sealing engagement between the mold end 86 of the nozzle 64 and the sprue bush during injection of a melt of material. In operation, the semispherical tip 90 is in force sealing engagement with the complimentary concave semispherical opening in the sprue bushing.
[0090] Referring now to FIGS. 7 and 8, an accumulator section, generally indicated as 64 is described. The accumulator includes an elongate section 104 , and a first barrel coupler 46 . In an embodiment of the invention, the coupler 46 includes an axial force linkage member, indicated as 96 , and a thermal isolator, indicated as 98 . Alternatively, the coupler 46 may include a linkage insulator 99 which is an axial force linkage member 96 integrated with a thermal isolator 98 . An axial melt channel extends through the accumulator 64 . The axial melt channel includes a first accumulator diameter bore 112 , a second concentrator 110 , and a second diameter bore 116 . The first accumulator diameter bore 112 aligns and connects with the first diameter bore 80 of the nozzle 62 . The second diameter bore 116 aligns and connects with an axial bore 147 of the second barrel portion 48 (not shown). The volume defined by the second diameter bore 116 (which defines an accumulation zone) determines the maximum available shot size for injection into a mold.
[0091] The accumulator 64 is substantially cylindrical with a suitable wall thickness (between the outer surface of the elongate section 104 and the melt channel) to withstand high pressure due to injection and reactive injection force. In an embodiment of the invention, the wall thickness of the accumulator 64 must also withstand axial carriage force.
[0092] The nozzle 62 connects to an end wall 118 of the accumulator 64 through the flange 72 of the nozzle 62 . The end wall 118 of the accumulator 64 includes a plurality of threaded bores 108 . The flange 72 of the nozzle 62 includes a corresponding plurality of bores 74 . Bolts interconnect the nozzle 62 to the accumulator 64 by the bores 74 and threaded bores 108 . The bore 114 in the accumulator 64 is of complimentary diameter to tightly receive the spigot 78 of the nozzle for sealing engagement between the nozzle 62 and the accumulator 64 . Alternatively, a seal may be installed to prevent leakage between the nozzle 62 and the accumulator 64 . Heater bands are conventionally secured to an outer surface of the accumulator 64 and the side 126 of the coupler 46 .
[0093] In an embodiment of the invention, the coupler 46 is integrally formed on an end of the accumulator 64 . Alternatively, the coupler 46 may be a separate component retained or secured to the accumulator 46 . For example, the coupler 46 may be welded to the outer surface of the accumulator 64 , or threaded to the accumulator 64 . Those skilled in the art will appreciate that any retained or secured connection must be designed to withstand axial forces.
[0094] In an embodiment of the invention, the coupler 46 includes an axial force linkage member 96 . For the embodiment illustrated, the axial force linkage member 96 is a pair of outwardly extending members integrally formed on the first end wall 120 of the coupler 46 . Alternatively, the axial force linkage member 96 may be a plurality of outwardly extending members, or a plurality of standoff posts, or a cylindrical ring member that may be integral or separate from the coupler 46 . In another embodiment of the invention, the coupler 46 includes a pair of axial force linkage members ( 150 , 96 , see FIG. 21 and FIG. 23) disposed on the first end wall 120 and the second wall 124 of the coupler 46 .
[0095] Those skilled in the art will appreciate that the cross sectional area of the force linkage member 96 of the coupler 46 is such to withstand the required axial forces. In addition, placement of the axial force linkage member 96 is such to provide an even symmetrical load distribution.
[0096] Alternatively, the coupler 46 may include a second axial force linkage member (or linkage insulator) located on a second end wall 124 of the coupler 46 .
[0097] In an embodiment of the invention, the axial force linkage member 96 includes a thermal isolator, generally indicated as 98 . For the embodiment illustrated, the thermal isolator 98 is integrally formed on an end of the axial force linkage member 96 . By minimizing the cross sectional area of the linkage member 96 for contact with a first carriage coupler (not shown) in the cradle member 52 . In operation, the thermal isolator reduces the conductive heat transfer from the hot accumulator 64 and the coupler 46 to the cradle member 52 and the yoke 50 . Alternatively, the thermal isolator may be separate from the axial force linkage member 96 , or may be a coating, or may be a different material for reducing the conductive heat transfer. The thermal isolator is disposed intermediate all contacting surfaces between the first barrel coupler 46 and the first carriage coupler. Those skilled in the art will appreciate that the thermal isolator is such to withstand the required axial forces.
[0098] The nozzle 62 and the accumulator 64 together form the first barrel portion 44 of the barrel assembly. The first barrel portion 44 optionally includes a liner or protective coating to protect the melt channel from abrasive and corrosive materials.
[0099] Referring now to FIGS. 9 and 10, a second barrel portion 48 is described. The second barrel portion 48 shown is a feed section of the barrel assembly 30 and includes an axial bore 147 , a first opening 146 , a second opening 134 , and a feed throat 140 . Material enters the second portion 48 through the feed throat 140 . A screw (not shown) disposed in the axial bore 128 conveys the material forward in the axial bore 147 towards accumulator 64 .
[0100] The second barrel portion 48 is substantially cylindrical with a suitable wall thickness (between the outer surface of the elongate barrel and the axial bore 147 acting as a melt channel) to withstand pressure developed due to compacting and sheering the feed material. Axial forces are not directed through the second barrel portion 48 .
[0101] The second barrel portion 48 optionally includes a liner 138 installed within an outer barrel 142 to protect the barrel from abrasive and corrosive materials.
[0102] The opening 146 permits the installation and removal of a screw (not shown) within the axial bore 147 .
[0103] The second end wall 136 of the second portion 48 connects to the coupler side of the accumulator 64 through the flange 130 . The end wall 120 of the coupler 46 includes a plurality of threaded bores 102 . The flange 130 of the second portion 48 includes a corresponding plurality of bores 132 . Bolts interconnect the second portion 48 to the coupler 46 by the bores 132 and thread bores 102 . The bore 100 in the coupler 46 is of complimentary diameter to tightly receive the cylindrical connector 128 of the second portion 48 for sealing engagement between the coupler 46 and the second portion 48 . The bore 122 in the coupler 46 is of complimentary diameter to receive the flange 130 . Alternatively, a seal may be installed to prevent leakage between the first portion and the second portion 48 . The second diameter bore 116 of the accumulator 64 axially aligns with the axial bore 147 of the second portion 48 .
[0104] A second barrel coupler 60 is formed on an end of the second portion 48 . The second barrel coupler 60 includes at least one engagement member, indicated as 153 for complimentary engagement with a cradle engagement member for preventing rotational movement of the barrel assembly 30 during operational rotation of the screw (not shown). Heater bands are conventionally secured to an outer surface of the second barrel portion 48 .
[0105] In the embodiment illustrated, the engagement member 153 is a flat recess machined on the outer surface of the barrel. Alternatively, the engagement member 153 may be an outwardly projecting member, or a groove, or a slot, or splined. Optionally, another recess 155 engages a removal plate (not shown) for preventing the barrel assembly from tipping forward when released from the cradle assembly and aligning the second barrel section vertically with the drive assembly.
[0106] In an application of the machine where the melt of material is a metal in a thixotropic state, for example, magnesium, the nozzle 62 may be made from DIN 2888 or DIN 2999. The accumulator 44 and first barrel coupler 68 (including the axial force isolator) may be made from Inconel 718 with a Stellite 12 liner. The second portion 48 may be also made from Inconel 718 with a Stellite 12 liner.
[0107] In an application of the machine where the melt of material is plastic, the nozzle 62 may be made from SAE 4140 steel with an H13 tip. The accumulator 44 and first barrel coupler 68 (including the axial force isolator) may be made from 4140 with a cast liner. The second portion 48 may be made from 4140 with a cast liner.
[0108] The nozzle 62 , accumulator 44 , first barrel coupler 68 , and second portion 48 may be machined from a billet of material, or alternatively, they may be formed by a hot isostatic pressing (HIP) process and then machined.
[0109] Referring now to FIGS. 3 and 11, the cradle member 52 of the carriage assembly 34 is further described. The cradle member 52 is substantially rectangular as shown in the top view of FIG. 11. A first cradle coupler 178 if formed on one end of the cradle member 52 . A drive mount 54 is formed on a second end of the cradle member 52 . The drive mount 54 includes an axial bore to connect the drive assembly to an end of a screw located in an axial bore of a barrel (not shown). The first cradle coupler 178 and the drive mount 54 are aligned about a longitudinal axis of the cradle member 52 .
[0110] The first cradle coupler 178 and the drive mount 54 are interconnected by a first carriage actuator housing 170 and a second carriage actuator housing 172 .
[0111] The first carriage housing 170 forms a lengthwise U-shaped rectangular channel for housing a first carriage actuator 56 . The first carriage housing 170 includes a support web 180 located near an end of the first carriage housing 170 and extends between an upper carriage member 182 and a lower carriage member 184 . An upright wall member 192 connects the upper carriage member 182 and the lower carriage member 184 .
[0112] The second carriage housing 172 forms a second lengthwise U-shaped rectangular channel for housing a second carriage actuator 58 . The second carriage housing 172 includes a support web 186 located near an end of the second carriage housing 172 and extends between an upper carriage member 188 and a lower carriage member 190 . A second upright wall member 194 connects the upper carriage member 188 and the lower carriage member 190 .
[0113] The cradle member 52 has a lengthwise axial opening 176 extending from the first end 174 of the cradle member 52 to the drive mount 54 . This opening provides clear unobstructed access for inserting and removing a barrel assembly (see FIG. 3) within the cradle member 52 .
[0114] Referring now to FIG. 11 and FIG. 12, the first cradle coupler 178 and the second carriage coupler 148 are further described.
[0115] The cradle member 52 includes a second support 206 that extends between the upright wall members ( 192 , 194 ) at the first end 174 of the cradle member 52 . In an embodiment of the invention, a first cradle coupler 148 includes a first coupling member 208 and a second coupling member 210 . The first and second coupling members ( 208 , 210 ) extend outwardly from the upright wall members ( 190 , 192 ). The first coupling member 208 includes a first coupling surface 212 and the second coupling member 210 includes a second coupling surface 214 . The first cradle coupler 178 forms an opening about the longitudinal axis to receive the first barrel coupler 46 . In an embodiment of the invention, the first coupling surface 212 and the second coupling surface 214 engage the axial force linkage member 96 the barrel coupler 60 . Alternatively, the first coupling surface 212 and the second coupling surface 214 engage the thermal isolator 98 . A pair of support gussets 216 extend between a back surface of the first and second coupling members ( 208 , 210 ) and the upright wall members ( 192 , 194 ).
[0116] The cradle member 52 also includes a first support 196 that extends between the upright wall members ( 192 , 194 ) and the drive mount 54 . The first support 196 is T shaped. In an embodiment of the invention, the second carriage coupler 148 includes a first coupler member 198 and a second coupler member 200 . The first and second coupler members ( 198 , 200 ) extend upwardly from an upper surface first support 196 and outwardly from the upright wall members ( 192 , 194 ). The second carriage coupler 148 forms a opening about the longitudinal axis to receive the second barrel coupler 60 . A first coupling surface 202 and a second coupling surface 204 engage complimentary surfaces ( 153 ) of the second barrel coupler 60 .
[0117] A first barrel support member 218 is formed on an upper surface of the second support 206 . The first barrel support member 218 includes a first upright standoff 222 and a second upright standoff 224 . The standoffs ( 222 , 224 ) are of a height above the upper surface of the second support 206 to engage an outer surface of the barrel assembly 30 for locating the first barrel coupler 46 with respect to the first cradle coupler 178 .
[0118] A second barrel support member 220 is formed on an upper surface of the first support 196 . The second barrel support member 220 includes a first upright standoff 226 and a second upright standoff 228 . The standoffs ( 226 , 228 ) are of a height about the upper surface of the second first support 196 to engage an outer surface of the barrel assembly 30 for locating the second barrel coupler 60 with respect to the second carriage coupler 148 .
[0119] The first barrel support member 218 and the second barrel support member 220 form a barrel alignment member and axially align the barrel assembly 30 when housed in the cradle member 34 . The cradle member 52 may include additional barrel support members.
[0120] Referring now to FIG. 13, the first end 174 and first cradle coupler 178 of the cradle member 52 are described. A yoke mounting surface 230 extends between the first carriage housing 170 and the second carriage housing 172 . The yoke mounting surface 230 includes a number of threaded bores for receiving bolts to secure the yoke 50 to the cradle member 52 . The first upright standoff 222 and the second upright standoff 224 are spaced apart a distance to securely support an outer surface of the barrel assembly 30 . The cross sectional area of the first coupling surface 212 and the second coupling surface 214 is selected to withstand and distribute axial carriage force to the first barrel coupler 46 . The first barrel coupler 46 fits into the barrel coupler opening, generally indicated as 232 .
[0121] Referring now to FIG. 14, the drive mount 54 of the cradle member 52 is further described. The drive mount 54 includes a mounting surface 234 for mounting a drive assembly 36 . A number of thread bores 236 are provided to receive bolts for mounting the drive assembly 36 to the drive mount 54 . A opening 238 is provided to connect the drive assembly 36 to an end of a screw mounted in a barrel (not shown).
[0122] Referring now to FIGS. 15, 16, and 17 , the yoke 50 is further described. The yoke 50 is rectangular having a front face 240 , a back face 242 , a left side 244 , a right side 246 , top and bottom. The yoke 50 is of suitable thickness to withstand axial carriage force. The yoke 50 includes a number of openings 248 for receiving bolts to secure the yoke 50 to the yoke mounting surface 230 of the cradle member 52 . The central axial bore 250 has a first diameter for receiving the barrel assembly 30 and a second diameter for receiving the barrel coupler 46 . The coupling surface of the yoke 50 engages the second axial force linkage member 150 . In an embodiment of the invention, the coupling surface is a barrel seat 252 formed between the first diameter and the second diameter. The barrel seat 254 has a cross sectional area to withstand and distribute axial carriage force.
[0123] In an embodiment of the invention, the first carriage coupler 152 is formed by the yoke 50 and the first cradle coupler 178 of the cradle member 34 .
[0124] The yoke 50 includes a pair of yoke supports ( 254 , 258 ). A first yoke support 254 is mounted on a side of the yoke 50 . A second yoke support 258 is mounted on another side of the yoke 50 , opposite the first yoke support 254 . The yoke supports are axially aligned. The first yoke support 254 includes a supporting surface 256 and the second yoke support 258 includes a supporting surface 260 . The supporting surfaces ( 256 , 260 ) engage complimentary surfaces of the first carriage actuator 56 and the second carriage actuator 58 for supporting the yoke 50 during assembly of the carriage assembly 34 .
[0125] In an embodiment of the invention, the yoke is plate steel A 36 and the cradle assembly is cast from A 536. Alternatively, the cradle assembly may be a pair of couplers interconnected by tie bars.
[0126] In an alternative embodiment of the invention, the first carriage coupler is interconnected to the second carriage coupler by a plurality of tie bars. In another alternative embodiment of the invention, the first carriage coupler is interconnected to the second carriage coupler by frame member.
[0127] Installation of the barrel assembly 30 in the carriage assembly 52 is described with reference to FIGS. 18 and 19. The cradle member 52 is mounted on the frame 28 of the injection unit 14 for axial movement of the injection assembly with respect to the injection unit frame 28 (not shown). The carriage actuator 42 is mounted in the cradle member 52 and connected to a stationary member, for example the stationary platen 16 of the injection molding machine 10 . The carriage actuator 42 is operated to move the cradle member 52 away from the stationary platen 16 (see FIG. 18). The yoke 50 is placed on the carriage actuator 42 away from the first end 174 of the cradle member 52 . The supporting surface 256 engages one actuator and the supporting surface 260 engages the other actuator.
[0128] The barrel assembly 30 is lowered into the opening of the cradle member 34 . The first barrel coupler 46 is aligned with the first cradle coupler 178 . The second barrel coupler 60 is aligned with the second carriage coupler 148 . The barrel assembly 30 is lowered until the barrel assembly 30 engages the first barrel support member 218 and the second barrel support member 200 . The barrel support members ( 218 , 200 ) align the barrel assembly 30 in the cradle member 34 .
[0129] A rectangular retaining plate 262 (see FIG. 19) engages the support surface 155 of the second barrel coupler 60 for retaining the barrel assembly 30 vertically in the cradle member 52 . The plate 262 is secured by conventional bolts to the first and second coupler member ( 200 , 198 ). A lower surface of the plate 262 engages the support surface 155 permitting axial movement of the barrel assembly 30 in the carriage assembly 34 .
[0130] The yoke 50 is moved towards the first end 174 of the cradle member 52 and secured to the first end 174 of the cradle member 52 by a number of bolts. A number of alignment pins and openings are provided between the yoke 50 and the yoke mounting surface 230 for aligning the yoke 50 to the cradle assembly 34 . The first barrel coupler 46 is effectively secured and clamped to the carriage assembly. The reciprocating screw (located within the axial bore of the barrel assembly) is then connected to the drive assembly 36
[0131] Those skilled in the art will appreciate that removal of the barrel assembly 30 from the carriage assembly 52 is the reverse operation of mounting.
[0132] Referring now to FIG. 20, the barrel assembly 30 and second barrel coupler 60 are shown mounted in the carriage assembly 34 as a top view without the yoke 50 .
[0133] The second barrel coupler 60 engages the second carriage coupler 148 , retaining the second barrel portion 48 of the barrel assembly 30 to the cradle member 52 . The second barrel coupler 60 and the second carriage coupler 148 prevent the barrel assembly 30 from rotating about the longitudinal axis during rotational operation of the screw (not shown) . The second barrel coupler 60 and the second carriage coupler 148 permit axial longitudinal movement of the second barrel portion 48 effectively isolating the second barrel portion from axial forces.
[0134] Referring now to FIG. 21, a partial view of the barrel assembly 30 is shown mounted in the carriage assembly 34 as a partial cross sectional view taken along line BB of FIG. 2.
[0135] The barrel assembly 30 is housed and secured in the carriage assembly 34 . In an embodiment of the invention, the thermal isolator and the first axial force linkage member 96 engages a surface of the first carriage coupler 152 . A ring shaped second axial force linkage member 150 is located on a other side of the coupler 46 . A thermal isolator surface of the second axial force linkage member 150 engages an inner surface (barrel seat) of the yoke 50 . The yoke 50 is located at the front of the carriage assembly 34 . The yoke 50 is bolted to a forward section of the carriage assembly 34 to securely clamp the first barrel coupler 46 .
[0136] The clamping force to secure the barrel assembly 30 with the carriage assembly 34 is provided between the yoke 50 and the carriage assembly 34 . The clamping force is directed through the second axial force linkage member 150 (including a thermal isolator), the first barrel coupler 46 , and the first axial force linkage member 96 (including a thermal isolator).
[0137] In operation, there are two different applications where axial carriage force is directed through the barrel coupler 46 . When the nozzle 62 includes a spigot tip 88 (see FIG. 5), the yoke includes a first carriage stop 156 and a second carriage stop 158 (alternatively, a single carriage stop). The first and second stop are mounted by bolts to a front face of the yoke 50 . The first and second stop extend outwardly from the front face of the yoke 50 to engage a surface of the stationary platen. The length of the first and second stop is such to permit a length of the spigot tip 88 to enter into the sprue bushing. Operation of the carriage actuator 42 moves the carriage assembly 34 and barrel assembly 30 towards the stationary platen 16 (see FIG. 1) until the first and second stop engage the stationary platen 16 preventing further forward movement. The carriage actuator 42 is further operated to create the axial carriage force. The axial carriage force is directed through the first carriage actuator 56 and the second carriage actuator 58 to the carriage assembly 34 . The carriage assembly 34 further directs the axial carriage force through the first carriage coupler 152 to the first axial force linkage member 96 , the first barrel coupler 46 , the second axial force linkage member 150 , the yoke 50 , and the first and second stops. This isolates the second barrel portion 48 from axial carriage force.
[0138] Referring now to FIG. 22, axial injection force is described. During the injection phase, the screw translation drive 38 is operated to move the screw forward in the barrel assembly 30 . An injection force is directed from the translation drive 38 to the reciprocating screw body 164 , and to the melt of material located in front of the reciprocating screw. A reactive injection force is directed back through the accumulator 64 , to the first barrel coupler 46 , (including linkage members) to the first cradle coupler 152 , to the first and second carriage actuator housings ( 170 , 172 ), to the drive mount 54 , and to the screw translation drive assembly 30 . The second barrel portion is isolated from the axial reactive injection force.
[0139] Referring now to FIG. 23, when the nozzle 62 includes a semispherical tip 90 (see FIG. 6), the first stop 156 and the second stop 158 are not required. Operation of the carriage actuator 42 moves the carriage assembly 34 and barrel assembly 30 towards the stationary platen 16 unit the semispherical tip 90 engages the sprue bushing. The carriage actuator 42 is further operated to create the axial carriage force. The axial carriage force is directed through the first carriage actuator 56 and the second carriage actuator 58 to the carriage assembly 34 . The carriage assembly 34 further directs the axial carriage force through the first carriage coupler 152 to the first axial force linkage member 96 , the first barrel coupler 46 , the accumulator 64 , and the nozzle 62 . The first barrel portion distributes axial carriage force and the second barrel portion is isolated from axial carriage force.
[0140] Referring now to FIG. 24, axial injection force is described. During the injection phase, the screw translation drive 38 is operated to move the screw forward in the barrel assembly 30 . An injection force is directed from the translation drive 38 to the reciprocating screw body 164 , and to the melt of material located in front of the reciprocating screw. A first reactive injection force is directed back through the accumulator 64 , to the first barrel coupler 46 , (including linkage members) to the first cradle coupler 152 , to the first and second carriage actuator housings ( 170 , 172 ), to the drive mount 54 , and to the screw translation drive assembly 30 . A second reactive injection force is directed back through the nozzle 62 to the accumulator 64 , to the first barrel coupler 46 , (including linkage members) to the first cradle coupler 152 , to the first and second carriage actuator housings ( 170 , 172 ), to the drive mount 54 , and to the screw translation drive assembly 30 . The second barrel portion is isolated from the axial reactive injection force.
[0141] Referring now to FIGS. 25 and 26, operation of a screw in a the barrel assembly is described. The barrel assembly, including the nozzle 62 , accumulator 64 , first barrel coupler 46 , second barrel portion 48 , and second barrel coupler 60 is secured and retained respectively in the carriage assembly 34 as previously described. A screw is located within the axial bore of the accumulator and the second barrel portion. The screw includes a screw tip 160 , a check valve 162 , and a reciprocating screw body 164 . The screw is reciprocatable between an injected position (see FIG. 13) and a maximum shot position (see FIG. 14).
[0142] In operation, the screw starts at the injected position. Feed material enters the axial bore of the barrel assembly through the feed port. The material is melted and conveyed forward along the screw body 164 towards the screw tip 160 . As a shot of material develops in front of the screw tip 160 in the accumulation zone of the accumulator 64 , the screw moves aft until an appropriate shot volume is received in the accumulator zone. Then, the screw is advanced forward injecting the shot of melt into a mold. The check valve 162 permits the melt to move forward, but not backward of the check valve. In operation, the check valve reciprocates only within the axial bore of the accumulator 64 .
[0143] In an embodiment of the invention, the barrel assembly is formed by a single unitary construction. In another embodiment, the barrel assembly is a first section connected to a second section. In another embodiment, the first section is a nozzle connected to an accumulator. In another embodiment, the first section is nozzle connected to a barrel head which is connected to an accumulator.
[0144] It is to be understood by persons skilled in the art that the invention is not limited to the illustrations described herein, which are deemed to illustrate the best modes of carrying out the invention, and which are susceptible to modification of form, size, arrangement of parts and details of operation. The invention is intended to encompass all such modifications, which are within its spirit and scope as defined by the claims.
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The invention relates broadly to injection molding machines and more particularly to a novel barrel assembly for use in an injection unit of an injection molding machine.
Barrels are conventionally mounted at an end in a carriage of an injection unit. Axial carriage force is directed along the entire length of the barrel which requires a thick barrel wall to withstand the axial carriage force.
A barrel assembly is disclosed having a first barrel coupler and a second barrel coupler. The first barrel coupler secures the barrel intermediate the ends of the barrel to a carriage. The second barrel coupler retains an end of the barrel in the carriage preventing rotation of the barrel during operation. The barrel section between the first barrel coupler and an end of the barrel is isolated from axial carriage force in operation.
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BACKGROUND OF THE INVENTION
The present invention relates to an arrangement for converting a wide, delivered stream of bottles into a single-track stream of bottles that is to be withdrawn. A feed mechanism conveys the wide stream of bottles to a conversion region, from where the bottles pass into a withdrawing mechanism that conveys the single-track stream of bottles. The conversion region and the withdrawing mechanism are disposed at essentially the same levels as the feed mechanism. Guide rails are provided at the sides of the feed mechanism, conversion region, and withdrawing mechanism, with those guide rails that are disposed on a given side of the feed mechanism, conversion region, and withdrawing mechanism being connected to one another.
With one heretofore known arrangement of this general type, a so-called wide-track conveyer is disposed at right angles to the conveying direction of the conveyer belts of an intermediate conveyer, the number of conveyer belts of which decrease in the conveying direction to a single conveyer belt, namely the conveyer belt of the withdrawing mechanism. The first and wider track of the intermediate conveyer has a constantly increasing belt speed. This intermediate conveyer effects the conversion of the multi-track stream of bottles to a single-track stream of bottles accompanied by the action of a guide rail that extends from the wide-track conveyer to the withdrawing mechanism, and is transverse to the stream of bottles. See German Offenlegungsschrift No. 31 29 057.
Not only does an arrangement of this type require a lot of space for the relatively long multi-track conversion section that narrows in stages, and expensive and complicated drive mechanisms for realizing the constantly increasing belt speeds for the individual tracks, but it also necessitates large sliding movements for the redistribution of the bottles that takes place during the conversion process. As a result, the bottles have to be transported in a free-standing manner over long stretches. In so doing, bottles fall over, and considerable noise results.
It is an object of the present invention to simplify the conversion of a stream of bottles while to the greatest extent possible eliminating the need for the expensive and space-consuming conversion stretches of the heretofore known arrangement. It is a further object of the present invention to embody the arrangement for accomplishing this in such a way that with the least possible sliding movement of the bottles during the redistribution, it is also possible in the simple manner to realize any angle between the conveying direction of the feed mechanism and the conveying direction of the withdrawing mechanism, in order in this manner to be able to better utilize the existing space conditions than was previously possible.
BRIEF DESCRIPTION OF THE DRAWINGS
These objects, and other objects and advantages of the present invention, will appear more clearly from the following specification in conjunction with the accompanying schematic drawings, in which:
FIG. 1 is a plan view of one inventive arrangement for converting rows of bottles, with the conveying direction of the feed mechanism forming an angle with the conveying direction of the withdrawing mechanism;
FIG. 2 shows the arrangement of FIG. 1, loaded with bottles;
FIG. 3 shows the arrangement of FIG. 1, with a transfer plate that is formed of a plurality of slide plates and has a transfer edge;
FIG. 4 shows an inventive arrangement having a withdrawing mechanism that conveys the single-track stream of bottles in the conveying direction of the conveying region, and also has a deflector disposed in the conveying region;
FIG. 5 shows an inventive arrangement having a conveying region, the conveying direction of which forms an obtuse angle with the conveying direction of the feed mechanism; and
FIG. 6 shows an inventive arrangement where the conveying direction in the withdrawing mechanism is parallel to the conveying direction in the feed mechanism and at 60° to the transfer edge.
SUMMARY OF THE INVENTION
The arrangement of the present invention is characterized primarily in that the conversion region embraces a conveying region of the withdrawing mechanism, and a transfer plate that is disposed downstream in the conveying direction of the top run of the conveyer belts of the feed mechanism, with this conveying region of the withdrawing mechanism having a wider conveying surface than does that region of the withdrawing mechanism that conveys the single-track stream of the bottles; the conveying direction of this conveying region of the withdrawing mechanism forms an angle with the transfer edge, of the transfer plate, that is disposed in the conversion region and extends at an angle other than a right angle relative to the direction in which bottles are conveyed in the feed mechanism; the transfer plate has a width corresponding to the track width of the feed mechanism, and is disposed downstream of the latter at essentially the same level; a guide means is associated with the conveying region of the withdrawing mechanism, and narrows the conveying path.
Further specific features of the present invention will be described subsequently.
By the inventive use of a transfer plate that is at the same level as the feed mechanism and the withdrawing mechanism, and that has a transfer edge, in conjunction with a transfer region of the withdrawing mechanism that is disposed at an angle of greater than 12° to this transfer edge, with which conveying region there is associated a guide means, such as guide rails, that narrow the stream of bottles, the conversion of the multi-track stream of bottles into a single-track stream of bottles is operatively extremely reliably achieved in an amazingly simple manner. The long conveyer belts, including the drives therefore, previously required for the conversion region are thereby eliminated.
Since the bottles are fed in rows to the withdrawing mechanism, and are removed at an angle from the region of the transfer edge before the next row of bottles reaches the withdrawing mechanism, a disturbance-free redistribution of the fed bottles is effected in short sections. To the greatest extent possible, this prevents the bottles from falling over. The inventive arrangement also operates at a relatively low noise level, since due to the configuration in the conversion region, little disturbance is produced within the stream of bottles.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now to the drawings in detail, FIG. 1 illustrates the conversion region C of one embodiment of the inventive arrangement. To feed the bottles indicated in FIG. 2 to the conversion region C, this arrangement is provided with a feed mechanism 19 that has a plurality, for example three, of parallel conveyer belts 22, 23, 24 that rotate endlessly and at the same speed. Each of these conveyer belts includes a hinged belt coupling, and is driven by a non-illustrated drive mechanism. The upper sides or runs of the conveyer belts 22, 23, and 24 together form a horizontally extending conveyer surface that is delimited on the sides by the guide rails 20, 21.
Also provided is a withdrawing mechanism 13 for conveying the bottles further. The conveying direction 5 of this withdrawing mechanism 13 forms an angle with the conveying direction 6 of the feed mechanism 19. As a variation of the orientation illustrated in FIG. 1, the feed mechanism 19 and the withdrawing mechanism 13 can be disposed in such a way that the conveying directions 5 and 6 form an obtuse angle, as illustrated in FIG. 5. The withdrawing mechanism 13 is provided on the sides with guide rails 14, 15, and is also provided with a conveyer belt 16 and a second conveyer belt 17 that is disposed in that conveying region 18 that is associated with the conversion region C. Both of the conveyer belts 16, 17 provide curved guidance, and are, for example, in the form of hinged belt couplings. However, these conveyer belts can also extend linearly, as illustrated in FIGS. 4 and 5. The conveyer belt 17 ends after the conversion region C, whereas the conveyer belt 16 continues linearly from the conversion region C in the conveying direction of the feed mechanism 19. However, as indicated by dashed lines in FIG. 1, the conveyer belt 16 can also end directly after the conversion region C, and the conveyer belt 17 can continue. Such a configuration is desirable if the single-track stream of bottles is to be withdrawn nearly at right angles to the conveying direction 6 of the feed mechanism 19.
The conveyer belt 16 of the withdrawing mechanism 13 leads to a non-illustrated bottle handling or treatment machine, such as a filling machine or a labeling machine. In the conveying region 18, the upper runs of the conveyer belts 16, 17 are disposed at the same level as the upper runs of the conveyer belts 22 to 24. In this connection, the guide rails 14, 15 form curved sections 14' and 15' in the conveying region 18, with the radii of these curved sections essentially conforming to the radius of curvature of the conveyer belts 16 and 17. However, the curved guide section 15' is different from the curved section 14'. This curved section 15' represents a means for narrowing the conveying path in the conveying region 18. For this function, the section 15' is guided over the upper run of the conveyer belt 16 in order in this way to delimit the conversion region C for the short rows of bottles F 1 to F n that are fed to this region.
In the transition region of the upper runs of the feed mechanism 19 to the common transport surface of the conveyer belts 16, 17 of the conveying region 18 of the withdrawing mechanism 13, there is provided an essentially level transition means in the form of a transfer plate 25. This transfer plate 25 forms a part of the conversion region C, and has a width corresponding to the track width of the feed mechanism 19. In the simplest case, the transfer plate 25 is in one piece, but can also, as shown in FIG. 3, comprise a plurality of slide plates 26, each of which is disposed above a return of the feed mechanism 19 from the upper run to the bottom run, as well as above the associated conveyer belt 16 of the withdrawing mechanism 13. On the transfer side disposed above the conveyer belt 16, the slide plates 26 are provided with a slanted edge 29. In this way, the slanted edges 29 of all of the slide plates 26 form a common transfer edge 30 for the reliable transfer of the bottles, in rows, to the conveyer belts 16, 17. This transfer edge 30 extends transverse to the conveying direction 6 of the conveyer belts 22 to 24 of the feed mechanism 19, and forms an angle of 60° with the direction 6. With this angular orientation, the transfer edge 30 and the conveying direction 5 that exists in the conveying region 18 form an angle α of 12° to 168°, and preferably 15°. The slide plates 26 that are provided with the slanted edges 29 can be rigidly connected to one another via a retaining plate 27 that is attached below (see FIG. 3).
The conveyer belts 16 and 17 of the withdrawing mechanism 13 are driven at the same or at different speeds; however, these conveyer belts 16, 17 are both driven at a speed greater than the speed of the conveyer belts 22 to 24 of the feed mechanism 19. The drive and control devices for accomplishing this are not illustrated.
After appropriately adjusting the speeds of the conveyer belts of the withdrawing mechanism 13 and the feed mechanism 19, a wide stream of bottles is delivered to the feed mechanism 19. The continuously fed bottles are then transferred via the transfer plate 25 onto the conveyer belts 16 and 17 of the curved-guidance withdrawing mechanism 13 in the manner illustrated in FIG. 2. Via the action of the conveyer belt 16, 17, the bottles that are transferred in rows onto the conveyer belts 16 and 17 over the transfer edge 30 are accelerated and withdrawn in the direction of the arrow 5, and, under the additional action of the curved, guiderail section 14', reach the linear portion of the withdrawing mechanism 13. Thus already after a short transport section, a single-track stream of bottles is formed between the guide rails 14 and 15; this single-track stream of bottles is eventially conveyed onto the conveyer belt 16. This conversion process is signficantly enhanced by the inclined orientation of the conveyer belts 16 and 17 of the withdrawing mechanism 13 at the angle α, preferably of 15°, to the transfer edge 30.
As can be clearly seen from FIG. 3, as a result of the inventive orientation each row of bottles F 1 transferred into the conveying region 18 of the conversion region C is immediately guided further in the direction of transport by the conveyer belts 16 and 17, thus removing this row from the vicinity of the transfer edge 30, so that place is provided for transfer of the next row of bottles F 2 . Each row of bottles F 1 to F n passes successively to the curved, guide-rail section 14' and thereupon to the guide rail 14, and is subsequently withdrawn, along with previously conveyed rows of bottles, as a single-track stream of bottles in the conveying direction of the feed mechanism 19. In the region of the curved, guide-rail sections 14' and 15', centrifugal forces are effective that accelerate the conversion process.
To rapidly form the single-track stream of bottles in a disturbance-free manner, it can be expedient, as shown in FIG. 1, to dispose a guide means at that guide rail 15 of the withdrawing mechanism 13 located across from the transfer edge 30 and extending on the side of the conveying region 18. This guide means can extend to the conveying path of the conveyer belt 16 and can, for example, be a deflector 31 that is embodied as a plate spring, a permanently elastic rail member, etc. If such a deflector 31 is provided, a respective row of bottles F 1 to F n that passes over the transfer edge 30 into the conveying region 18 is deflected onto the conveyer belt 16 that conveys the single-track stream of bottles out of the conversion region C.
It is also within the scope of the present invention to incline the feed mechanism 19, including the conversion region C, toward the withdrawal side by 1° to 12°, preferably 4° transverse to the conveying direction 5 and about a horizontal axis that extends in the conveying direction 6 of the feed mechanism 19. With this feature, the sloped output becomes effective during the conversion process, so that on the one hand this process is accelerated, and on the other hand the separation of bottles and pieces that have fallen over and are transported by the feed mechanism 19 is enhanced.
It is also within the scope of the present invention to conform the track width of the conveying region 18 of the withdrawing mechanism 13 to the feed mechanism 19 and the transfer plate 25 in such a way that the feed mechanism 19, the transfer plate 25, and the conveying region 18 extend in the same line, as shown in FIG. 6. This is the case if the angle α of the conveyer belt 16 that conveys in the direction 5 of the conveying region 18 is preferably 60°, with the conveying directions of the feed mechanism 19 and the conveying region 18 extending in the same direction. This confirmation of the track width provides for the conveying region 18 a number of conveyer belts 16, 17, 32 that corresponds to the number of conveyer belts 22 to 24 of the feed mechanism 19. In this connection, below the transfer plate 25 the returns of the conveyer belts 22 to 24 from the top run to the bottom run are disposed across from the returns of the conveyer belts 16, 17, 32 from their top runs to their bottom runs. With this embodiment also, it can be expedient to incline the feed mechanism 19, including the conversion region C formed by the transfer plate 25 and the conveying region 18, by 1° to 12°, preferably 4°, transverse to the conveying direction about a horizontal axis that extends in the conveying directions of the feed mechanism 19 and the conveying region 18. In particular, this inclination should be toward the long side that extends along the withdrawing conveyer belt 16 and the feeding conveyer belt 24 in order to accelerate the conversion process and enhance the separation of bottles and pieces that have fallen over and are being transported by the feed mechanism 19.
The present invention is, of course, in no way restricted to the specific disclosure of the specification and drawings, but also encompasses any modifications within the scope of the appended claims.
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An arrangement for converting a multi-track stream of bottles into a single-track stream of bottles. A conversion region is disposed between a feed mechanism that is provided with guide rails, and a withdrawing mechanism that is likewise provided with guide rails. The conversion region comprises a transfer plate and a conveying region of the withdrawing mechanism, with the conveyer belts of the latter being disposed at an angle to the transfer edge of the transfer plate. This transfer plate forms an essentially level transition between the conveyor belts of the feed mechanism and the conveyor belts of the conveying region of the withdrawing mechanism. Guide rails are also associated with the conversion region. These latter guide rails interconnect the guide rails of the feed mechanism and of the withdrawing mechanism. The track width of the transfer plate corresponds to the track width of the feed mechanism, and is disposed downstream of the latter when viewed in the direction of conveying.
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This application is a division of application Ser. No. 07/968,536 filed Oct. 29, 1992, U.S. Pat. No. 5,352,614, which is a continuation of application Ser. No. 07/857,826 filed Mar. 26, 1992; U.S. Pat. No. 5,184,200.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a thin film semiconductor device and, more particularly, to a thin film semiconductor device which can be also suitably used as a photoelectric converting device which can be used in an image processing apparatus such as facsimile, digital copying apparatus, image reader, or the like.
2. Related Background Art
A thin film semiconductor made of a non-monocrystalline semiconductor, particularly, non-monocrystalline silicon (polysilicon, crystallite silicon, and amorphous silicon) is suitably used as a photoelectric converting device which can be preferably used as a thin film semiconductor device in a photoelectric converting device having a large area or a long length. As a photoelectric converting device using a thin film semiconductor, there are two kinds of devices such as primary photo current type (photodiode type) device and secondary photo current type device. Although the primary photo-current type is a photoelectric converting device to extract electrons and holes generated by the incident light and photoelectrically convert, there is a problem such that a photo current which can be taken out as an output is small. On the other hand, according to the secondary photo current type photoelectric converting device, since a larger photo-current (secondary photo current) can be obtained as compared with that of the primary photo current type photoelectric converting device, it can be applied to apparatuses in a wider range and an attention is paid to it.
FIG. 1 is a schematic constructional diagram for explaining an example of the secondary photo current type photoelectric converting device. In FIG. 1, reference numeral 1011 denotes an insulative substrate such as glass or the like; 1012 a photoconductive semiconductor layer made of CdS-Se, amorphous silicon hydride (hereinafter, abbreviated to "a-Si:H") formed by a plasma CVD method or the like, etc.; 1013a and 1013b impurity layers for ohmic contact; and 1014a and 1014b electrodes. In the above construction, by applying a voltage across the electrodes 1014a and 1014b, a large secondary photo current flows and is photoelectrically converted when the light enters from the side of the substrate 1011 or the side of the electrodes 1014a and 1014b.
Further, a photoelectric converting device of the thin film transistor type having auxiliary electrodes to stabilize and improve the characteristics (photo current, dark current, etc.) is proposed. FIG. 2 is a schematic constructional diagram of a thin film transistor type photoelectric converting device having auxiliary electrodes. In FIG. 2, the same component elements as those shown in FIG. 1 are designated by the same reference numerals. In FIG. 2, reference numeral 1015 denotes a transparent or opaque gate electrode and 1016 indicates a gate insulative layer made of SiN x or the like and formed by a plasma CVD method or the like.
Further, a complete contact type photo sensor (photoelectric converting device) using the thin film transistor type photoelectric converting device of FIG. 2, a thin film transistor, and the like is proposed (JP-A-61-26365). FIG. 3 shows an example of such a circuit. FIG. 3 relates to the case of a sensor array having nine thin film transistor type photoelectric converting sections. In the diagram, one block is constructed by every three of thin film transistor type photoelectric converting sections E 1 to E 9 . Thus, three blocks are formed by the converting sections E 1 to E 9 . The sensor array is constructed by those three blocks. Capacitors C 1 to C 9 and switching transistors T 1 to T 9 are respectively connected to the converting sections E 1 to E 9 in. correspondence thereto. Individual electrodes of the photoelectric converting sections E 1 to E 9 are connected to corresponding proper one of common lines 3102 to 3104 through the switching transitors T 1 to T 9 . In more detail, the first switching transistors T 1 , T 4 , and T 7 of each block are connected to the common line 3102. The second switching transistors T 2 , T 5 , and T 8 of each block are connected to the common line 3103. The third switching transistors T 3 , T 6 , and T 9 of each block are connected to the common line 3104. The common lines 3102 to 3104 are connected to an amplifier 3105 through switching transistors T 10 to T 12 .
Gate electrodes of switching transistors ST 1 to ST 9 are commonly connected in a manner similar to the gate electrodes of the switching transistors T 1 to T 9 to parallel output terminals of a shift register 3109. Therefore, the switching transistors ST 1 to ST 9 are sequentially turned on every block by a shift timing of the shift register 3109.
In FIG. 3, the common lines 3102 to 3104 are respectively connected to the ground through capacitors C 10 to C 12 and to the ground through switching transistors CT 1 to CT 3 . A capacitance of each of the capacitors C 10 to C 12 is set to be sufficiently larger than that of each of the capacitors C 1 to C 9 . Gate electrodes of the switching transistors CT 1 to CT 3 are commonly connected and are also connected to a terminal 3108. That is, by applying a high level signal to the terminal 3108, the switching transistors CT 1 to CT 3 are simultaneously turned on, so that the common lines 3102 to 3104 are connected to the ground. Further, the photoelectric converting sections E 1 to E 9 have gate electrodes G 1 to G 9 .
FIG. 4 is a partial plan view of a one-dimensional complete contact sensor array formed on the basis of the circuit diagram shown in FIG. 3. In the diagram, reference numeral 3111 denotes a matrix-shaped wiring portion comprising the common lines 3102 to 3104 and the like; 3112 indicates a thin film transistor type photoelectric converting section; 3113 a charge accumulating section comprising the capacitors C 1 to C 9 ; 3114 a transfer switch which is constructed by the switching transistor T 1 to T 9 and uses thin film transistors having the same structure as that of the photoelectric converting section; 3115 a discharge switch which comprises the switching transistors ST 1 to ST 9 and uses thin film transistors having the same structure as that of the photoelectric converting section; 3116 an extension line to connect a signal output of the transfer switch 3114 to a signal processing "IC; and" 3117 a load capacitor which comprises the capacitors CT 1 to CT 3 and is used to accumulate the signal charges which have been transferred by the transfer switch 3114 and to read out the signal charges.
FIG. 5 is a cross sectional view taken along the line A-A' in FIG. 4. As will be obviously understood from FIG. 5, all of the thin film transistor type photoelectric converting section 3112, charge accumulating section 3113, transfer switch 3114, discharge switch 3115, matrix-shaped wiring section 3111, load capacitor 3117, and the like have a common construction in which a metal (gate electrode 1015 in the photoelectric converting section), an insulative layer (gate insulative layer 1016 in the photoelectric converting section), a photoconductive semiconductor layer (1012 in the photoelectric converting section), ohmic contact layers (1013a and 1013b in the photoelectric converting section), and metals (1014a and 1014b in the photoelectric converting section) are formed on the substrate 1011 in accordance with this order.
The sensor array shown in FIGS. 4 and 5 as mentioned above has the common construction in order to reduce the manufacturing costs by simultaneously manufacturing the photoelectric converting section and the drive circuit section. Particularly, when there is a high fine image reading request, the number of pixels must be increased, so that the drive circuit section which operates at a high speed is needed. However, when the thin film transistor as a thin film semiconductor device of the drive circuit section is made of a semiconductor material of a-Si:H, a mobility of the carrier lies within a range from 0.1 to 0.5 cm 2 ·C -1 ·S -1 and is not enough large. Consequently, there is a limitation in the charge transfer ability. To improve the charge transfer ability, in general, a size of thin film transistor as one of the thin film semiconductor devices is enlarged, the number of drive circuit sections is set to two, or the like. However, a size of photoelectric converting apparatus is consequently enlarged and the manufacturing costs are also increased. Therefore, it is demanded to realize a photoelectric converting apparatus in which the size is not enlarged and the costs are low and which is suitable for miniaturization and has a drive circuit section having an enough high transfer ability.
SUMMARY OF THE INVENTION
The invention is made in consideration of the above problems and it is an object of the invention to provide a photoelectric converting apparatus having a drive circuit section, in which a semiconductor layer comprising a crystallite layer and an amorphous layer is used as a semiconductor layer or a photoconductive semiconductor layer, so that the semiconductor layer not only has a good performance as a semiconductor device but also maintains a good performance as a photoelectric converting section, a thin film transistor and the like of the drive circuit section can be formed by a construction which is common to the photoelectric converting section, the costs are low, the size is not enlarged, and an enough high transfer ability is provided.
The above object of the present invention can be accomplished by a thin film semiconductor apparatus comprising at least: an insulative layer; a semiconductor layer provided in contact with the insulative layer; first and second electrodes provided in contact with the semiconductor layer; and a third electrode provided via the insulative layer, wherein the semiconductor layer is formed by a crystallite layer whose average grain diameter lies within a range from 50 to 350 Å and an amorphous layer.
With the above semiconductor structure, a mobility of carriers is high and an enough high charge transfer ability can be obtained.
As mentioned above, the average grain diameter of the crystallite layer in the invention lies within a range from 50 to 350 Å in consideration of the balance between the carrier mobility and the characteristics of the apparatus, an easiness in manufacturing, and the like. A thickness of crystallite layer is preferably set to a value within a range about from 500 to 2000 Å in consideration of an effective transfer of charges.
According to the invention, the crystallite layer of the semiconductor layer can be arranged on the insulative layer side. A material containing at least silicon and hydrogen can be used as a semiconductor layer. At least the crystallite layer of the semiconductor layer can be formed by alternately performing many times the step of depositing a non-monocrystalline layer and the step of irradiating a hydrogen plasma to the deposited non-monocrystalline layer. A second insulative layer is provided in contact with the first and second electrodes provided in contact with the side of the semiconductor layer which faces the insulative layer. A fourth electrode can be provided in contact with the second insulative layer. In this case, the crystallite layer of the semiconductor layer can be also arranged on the insulative layer side, that is, the above-described second insulative layer side.
The invention can be also obviously applied to a photoelectric converting apparatus (device) using the semiconductor layer as a photoconductive semiconductor layer.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic constructional diagram for explaining an example of a photoelectric converting device;
FIG. 2 is a schematic constructional diagram for explaining an example of a photoelectric converting device;
FIG. 3 is a circuit diagram of a photoelectric converting apparatus;
FIG. 4 is a partial plan view of a contact sensor array having the circuit of FIG. 3;
FIG. 5 is a cross-sectional view taken along the line A-A' of the contact sensor array of FIG. 4;
FIGS. 6, 10, and 12 are schematic constructional diagrams for explaining examples of photoelectric converting devices according to the invention, respectively;
FIG. 7 is a conceptional diagram of a plasma CVD apparatus used to form the photoelectric converting device of the invention;
FIG. 8 is a gas introducing timing diagram in the plasma CVD apparatus in the formation of the photoelectric converting device of the invention;
FIGS. 9, 11, and 13 are diagrams showing characteristics of the photoelectric converting devices, respectively; and
FIG. 14 is an installation diagram of a contact photo sensor array using the photoelectric converting device of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Embodiments of the present invention will be described hereinbelow with reference to the drawings.
Embodiment 1
FIG. 6 is a schematic constructional diagram of a photoelectric converting device of the invention. In the diagram, reference numeral 1011 denotes the substrate; 1016 the insulative layer; 1015 the third electrode (gate electrode); 1014a the first electrode (drain electrode); 1014b the second electrode (source electrode); 1013a and 1013b ohmic contact layers; and 1012 the photoconductive semiconductor layer. The photoconductive semiconductor layer 1012 has a double layer structure comprising: the a-Si:H layer 1012a on the side of the drain electrode 1014a and source electrode 1014b; and the crystallite layer 1012b on the side of the insulative layer 1016.
FIG. 7 is a constructional conceptional diagram for explaining an example of a plasma CVD apparatus used in manufacturing of the photoelectric converting device of the embodiment. In FIG. 7, reference numeral 70 denotes a reaction chamber; 11 a substrate in which functional layers such as a photoconductive semiconductor layer and the like are formed on the surface; 71 an anode electrode having a heater (not shown); 72 a cathode electrode; 73 a high frequency power source of 13.56 MHz; 74 an exhaust pump; 75 an SiH 4 gas introducing tube; 76 an H 2 gas (containing the Ar gas) introducing tube; 77 a microwave source of 2.45 GHz and a microwave applicator; and V 1 and V 2 valves to control the SiH 4 gas and H 2 gas, respectively. The valves V 1 and V 2 are connected to a computer to accurately control the opening/closing times.
The photoelectric converting device of the embodiment is manufactured in the following manner.
(1) A Cr layer having a film thickness of 0.1 μm is deposited onto the glass substrate 1011 (#7059 made by Corning Glass Works Co., Ltd.) by a sputtering method and is patterned into a desired pattern, thereby forming the gate electrode 1015.
(2) The substrate 1011 is set into the ordinary plasma CVD apparatus and a temperature of substrate is set to 350° C. After that, the SiH 4 gas, NH 3 gas, and H 2 gas are introduced at desired mixture ratios and the layer of SiN x :H is deposited, thereby forming the insulative layer 1016 having a film thickness of 3000 Å.
(3) Subsequently, the photoconductive semiconductor layer 1012 is deposited by the following procedure by using the plasma CVD apparatus shown in FIG. 7.
1 First, the substrate 1011 is set, the inside of the reaction chamber 70 is exhausted up to a predetermined pressure by the exhaust pump 74, and the substrate 1011 is simultaneously heated up to 340° C. by the heater (not shown).
2 The introducing timing of the SiH 4 gas and H 2 gas are controlled as shown in FIG. 8. That is, one unit (time t A ) having a time t 1 to deposit the film and a time t 2 to irradiate an H 2 plasma is repeated. For the film depositing time t 1 , both of the valves V 1 and V 2 are open, so that the SiH 4 gas, Ar gas, and H 2 gas are fed into the reaction chamber. The SiH 4 gas is set to 10 SCCM, the H 2 gas is set to 10 SCCM, and a pressure in the reaction chamber is adjusted to 0.1 Torr by the Ar gas. In this instance, a depositing speed is set to about 3 Å/sec. A thickness of film which is deposited for the time t 1 is set to about 5 Å. For the H 2 plasma irradiating time t 2 , the valve V 1 is closed, the valve V 2 is opened, and the H 2 plasma is irradiated. A quality of film deposited for the time t 1 changes in dependence on the H 2 plasma irradiating time t 2 . Particularly, it has been found that an amount of H contained in the film changes and, when the time t 2 is set to a value longer than 80 seconds, a crystallite layer is formed. In the embodiment, the crystallite layer 1012b having a film thickness of 1000 Å is formed on the insulative layer 1016 side by alternately repeating the processes for the above times t 1 and t 2 a number of times.
The substrate is cooled to 250° C. After that, the SiH 4 gas is set to 10 SCCM, the H 2 gas is set to 10 SCCM, the supply of the Ar gas is stopped, and the inside of the reaction chamber is set to 0.5 Torr, thereby depositing the a-Si:H layer 1012a having a film thickness of 4000 Å.
(4) The substrate is set into the ordinary plasma CVD apparatus and an ohmic contact layer having a film thickness of 1500 Å is formed by using the SiH 4 gas, PH 3 gas, and H 2 gas.
(5) Lastly, an Al layer having a thickness of 8000 Å is formed by a sputtering method and is patterned together with the above ohmic contact layer, thereby forming the ohmic contact layers 1013a and 1013b, drain electrode 1014a, and source electrode 1014b.
To examine the fundamental characteristics of the thin film transistor formed as mentioned above, a voltage within a range from -10 to 20 V is applied to the gate electrode 1015, a voltage of 1 V is applied to the drain electrode 1014a, and a voltage of 0 V is applied to the source electrode 1014b, and currents flowing between the drain electrode 1014a and the source electrode 1014b in both of the light irradiating mode and the light non-irradiating mode are measured. In FIG. 9, an axis of ordinate indicates the current flowing between the drain electrode 1014a and the source electrode 1014b and an axis of abscissa indicates a voltage V G of the gate electrode 1015. In FIG. 9, A and A' indicate characteristics of the thin film transistor according to the embodiment of the invention in both of the light irradiating mode and the light non-irradiating mode, respectively. B and B' show characteristics of the thin film transistor in both of the light irradiating mode and the light non-irradiating mode in the case where such a thin film transistor is formed by a method similar to the above method except that the step (3) of forming the crystallite layer 1012b among the steps (1) to (5) of forming the thin film transistor according to the embodiment of the invention and that the a-Si:H layer having a film thickness of 6000 Å is formed in the step of forming the a-Si:H layer 1012a. As shown in FIG. 9, when comparing the characteristics A' and B' in the light non-irradiating mode, in the case of the thin film transistor (shown by A') of the embodiment of the invention, the current (dark current) flowing across the source electrode and the drain electrode near the gate electrode voltage of 20 V is increased by tens of %. On the other hand, when comparing the characteristics A and B in the light irradiating mode, in both of the thin film transistor of the embodiment of the invention and the thin film transistor as a comparison example, similar currents (photo currents) flowing across the source electrode and the drain electrode are obtained.
From FIG. 9, it will be understood that the charge transfer ability of the thin film transistor of the embodiment of the invention is improved as compared with the charge transfer ability of the thin film transistor as a comparison example because of an increase in current between the source and drain electrodes in the light non-irradiating mode. It will be also understood that the current between the source and drain electrodes in the light irradiating mode in a region of V g ≦0 V where an enough large ratio between the photo current and the dark current can be obtained in the thin film transistor of the embodiment of the invention is almost similar to that of the thin film transistor as a comparison example, so that the transistor of the embodiment can also be used as a photoelectric converting section.
Embodiment 2
FIG. 10 is a schematic constructional diagram of a photoelectric converting device in which the charge transfer ability of the photoelectric converting device of the embodiment 1 is further improved. In the diagram, the same component elements as those in FIG. 6 are designated by the same reference numerals. In FIG. 10, reference numeral 1015b denotes a gate electrode and 1016b indicates a gate insulative layer made of SiN x or the like. The device of FIG. 10 differs from that of FIG. 6 with respect to the depositing depositions of an a-Si:H layer 1012a and a crystallite layer 1012b of the photoconductive semiconductor layer 1012 and the position of the gate electrode 1015b.
The photoelectric converting device of the embodiment 2 is manufactured in the following manner.
(1) The step (1) is similar to the step (3) in the embodiment 1 except that the forming order of the a-Si:H layer 1012a and the crystallite layer 1012b is reversed and the substrate temperature when the crystallite layer 1012b is formed is set to 230° C.
(2) The step (2) is similar to the step (4) in the embodiment 1.
(3) The step (3) is similar to the step (5) in the embodiment 1.
(4) The substrate 1011 is set into the ordinary plasma CVD apparatus and the substrate temperature is set to 220° C. After that, the SiH 4 gas, NH 3 gas, and H 2 gas are introduced at predetermined mixture ratios and an SiN x :H layer is deposited, thereby forming the insulative layer 1016b having a film thickness of 3000 Å.
(5) Lastly, an ITO transparent layer having a film thickness of 2000 Å is formed by a sputtering method and is patterned, thereby forming the transparent gate electrode 1015b.
To examine the fundamental characteristics of the thin film transistor formed as mentioned above, a voltage within a range from -10 to 20 V is applied to the gate electrode 1015b, a voltage of 1 V is applied to the drain electrode 1014a, a voltage of 0 V is applied to the source electrode 1014b, and currents flowing between the drain electrode 1014a and the source electrode 1014b in the light irradiating mode and the light non-irradiating mode are measured. In FIG. 11, an axis of ordinate indicates a current between the drain electrode 1014a and the source electrode 1014b and an axis of abscissa shows a voltage V G of the gate electrode 1015b. In FIG. 11, A and A' indicate the characteristics of the thin film transistor of the embodiment of the invention in both of the light irradiating mode and the light non-irradiating mode, respectively. B and B' indicate the characteristics of the thin film transistor as a comparison example in the light irradiating mode and the light non-irradiating mode, respectively, in the case where such a thin film transistor is formed by substantially the same forming method as the above method except that the step (1) of forming the crystallite layer 1012b among the steps (1) to (5) of forming the thin film transistor of the embodiment of the invention and that the a-Si:H layer having a film thickness of 6000 Å is formed in the step of forming the a-Si:H layer 1012a. As shown in FIG. 11, when comparing the characteristics A' and B' in the light non-irradiating mode, in the case of the thin film transistor of the embodiment of the invention, the current (dark current) flowing across the source and drain electrodes near the gate electrode voltage of 20 V is increased by about 1.5 digits. When comparing the characteristics A and B in the light irradiating mode, in both of the thin film transistor of the embodiment of the invention and the thin film transistor as a comparison example, the similar currents (photo currents) flowing across the source and drain electrodes are obtained.
It will be understood from FIG. 11 that the charge transfer ability of the thin film transistor of the embodiment of the invention is fairly improved as compared with the charge transfer ability of the thin film transistor as a comparison example due to a large increase in current flowing between the source and drain electrodes in the light non-irradiating mode. Since the current between the source and drain electrodes in the light irradiating mode in the thin film transistor of the embodiment of the invention is almost similar to that in the thin film transistor as a comparison example, it will be understood that the thin film transistor of the embodiment can also be used as a photoelectric converting section.
Embodiment 3
FIG. 12 is a schematic constructional diagram of a photoelectric converting device in which the charge transfer ability of the photoelectric converting device of the embodiment 1 is further improved. In FIG. 12, the component elements similar to those shown in FIG. 6 are designated by the same reference numerals. In FIG. 12, reference numeral 1015a denotes a third electrode (gate electrode); 1015b the fourth electrode (gate electrode); and 1016a and 1016b gate insulative layers made of SiN x or the like. The device of FIG. 12 largely differs from the device of FIG. 6 with respect to the depositing positions of the a-Si:H layer 1012a and the crystallite layer 1012b of the photoconductive semiconductor layer 1012 and the presence or absence of the gate electrode 1015b.
The photoelectric converting device of the embodiment is manufactured in the following manner.
(1) The step (1) is similar to the step (1) of the embodiment 1.
(2) The step (2) is similar to the step (2) of the embodiment 1.
(3) The step (3) is similar to the step (3) of the embodiment 1 except that the forming order of the a-Si:H layer 1012a and the crystallite layer 1012b is reversed and the substrate temperature when the crystallite layer 1012b is formed is set to 230° C.
(4) The step (4) is similar to the step (4) of the embodiment 1.
(5) The step (5) is similar to the step (5) of the embodiment 1.
(6) The substrate 1011 is set into the ordinary plasma CVD apparatus and the substrate temperature is set to 220° C. After that, the SiH 4 gas, NH 3 gas, and H 2 gas are introduced at predetermined mixture ratios and an SiN x :H layer is deposited, thereby forming the insulative layer 1016b having a film thickness of 3000 Å.
(7) Lastly, an ITO transparent layer having a film thickness of 2000 Å is formed by a sputtering method and is patterned, thereby forming the transparent gate electrode 1015b.
To examine the fundamental characteristics of the thin film transistor formed as mentioned above, a voltage within a range from -10 to 20 V is applied to the gate electrode 1015b, a voltage of 1 V is applied to the drain electrode 1014a, a voltage of 0 V is applied to the source electrode 1014b, and currents flowing between the drain electrode 1014a and the source electrode 1014b in both the light irradiating mode and the light non-irradiating mode are measured. The voltage of gate electrode 1015 is set to 0 V. The light enters from the direction on the side of the gate electrode 1015b. In FIG. 13, an axis of ordinate indicates the current flowing between the drain electrode 1014a and the source electrode 1014b and an axis of abscissa indicates the voltage V G of the gate electrode 1015b. In FIG. 13, A and A' indicate the characteristics of the thin film transistor of the embodiment of the invention in both of the light irradiating mode and the light non-irradiating mode, respectively. B and B' indicate the characteristics of the thin film transistor as a comparison example in the light irradiating mode and the light non-irradiating mode, respectively, in the case where such a thin film transistor is formed by substantially the same method as the foregoing method except that the step (3) of forming the crystallite layer 1012b among the steps (1) to (7) of forming the thin film transistor of the embodiment of the invention is omitted and that the a-Si:H layer having a film thickness of 6000 Å is formed in the step of forming the a-Si:H layer 1012a. As shown in FIG. 13, when comparing the characteristics A' and B' in the light non-irradiating mode, in the case of the thin film transistor of the embodiment of the invention, the current (dark current) flowing between the source and drain electrodes near the gate electrode voltage of 20 V is increased by about 1.5 digits. When comparing the characteristics A and B in the light irradiating mode, in both of the thin film transistor of the embodiment of the invention and the thin film transistor as a comparison example, the similar currents (photo currents) flowing between the source and drain electrodes are obtained.
It will be understood from FIG. 13 that the charge transfer ability of the thin film transistor of the embodiment of the invention is fairly improved as compared with the charge transfer ability of the thin film transistor as a comparison example due to a large increase in current across the source and drain electrodes in the light non-irradiating mode. Since the current flowing between the source and drain electrodes in the light irradiating mode in the thin film transistor of the embodiment of the invention is almost similar to that in the thin film transistor as a comparison example, it will be understood that the thin film transistor of the embodiment can also be sufficiently used as a photoelectric converting section.
Embodiment 4
A circuit as shown in FIG. 3 is constructed as a one-dimensional contact sensor array by using the photoelectric converting section comprising the thin film transistor formed in the second embodiment and the drive circuit section comprising such a thin film transistor or the like. In a manner similar to the embodiment 1, the various characteristics of the thin film transistor type photoelectric converting section are examined. Thus, the characteristics similar to those in the embodiment 1 were obtained. In the thin film transistor of the drive circuit section or the like, sufficient characteristics are shown and the charge transfer ability is improved by about one digit.
FIG. 14 is a cross-sectional view showing a state in which the photoelectric converting device of the invention is installed as a one-dimensional complete contact type photo sensor array. In FIG. 14, an abrasion resistant layer 121 made of glass or the like is formed through a protective layer 120 over the photoelectric converting section and the drive circuit section. An original 123 is illuminated by a light source 122 such as a light emitting diode or the like from the back side of the translucent substrate 1011 such as glass or the like, thereby reading the original 123. It will be obviously understood that the photo sensor array using the photoelectric converting device of the invention can be also used as a one-dimensional contact type photo sensor array using an equal magnification image forming lens.
In the above embodiments, SiH 4 , H 2 , and the like are used as materials to form the thin film. However, the invention is not limited to those materials but can also use materials containing F or the like or materials containing gases having a chemical formula of SiH 2n+2 (n is an integer of 2 or more). As silicon used in the invention, in addition to materials comprising at least silicon and hydrogen, silicon materials containing, for instance, fluorine or the like and other materials can be used.
According to the invention as described above, since the semiconductor layer or photoconductive semiconductor layer comprising the crystallite layer and the amorphous layer is used, it has a good performance as a semiconductor apparatus and a good performance is maintained as-a photoelectric converting section. Therefore, there is provided a photoelectric converting apparatus having a drive circuit section in which a thin film transistor or the like of the drive circuit section can be formed by a construction which is common to that of the photoelectric converting section, the costs are low, the size is not enlarged, and an enough high transfer ability is obtained.
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A semiconductor device comprises, at least, an insulative layer; a semiconductor layer provided in contact with the insulative layer; first and second electrodes provided in contact with the semiconductor layer; and a third electrode provided through the insulative layer. The semiconductor layer has a crystallite layer whose average grain diameter lies within a range from 50 to 350 Å and an amorphous layer.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] An improved method for producing ethanol, by treating carbohydrate material, carbohydrate broth or carbohydrate slurry throughout the fermentation process with a composition containing an aldehyde, a fatty acid, a terpene and a surfactant. Ethanol yields are improved by controlling the formation of biofilms and destroying pre-existing biofilms in the fermentation system.
[0003] 2. Background
[0004] High oil prices have brought about an increase on the search for renewable fuels. Ethanol is one of these renewable fuels which, when mixed with gasoline, can decreased the need for imported oil.
[0005] In 2009, the Renewable Fuels Standard (RFS) called for blending 11.1 billion gallons of ethanol and other biofuels into the U.S. motor fuels market to satisfy future demand. This will increase the level of corn needed by the industry, and will require plant capacity to be increased as well. In 2010, the USA's annual operating capacity increased by 2.7 billion gallons, a 34% increase over 2007 levels.
[0006] Ethanol, a promising biofuel from renewable resources, is produced from the starch of cereal grains (corn, sorghum, wheat, triticale, rye, malted barley, rice), tuber crops (potatoes) or by direct use of the sugar in molasses, sugar cane juice or sugar beet juice. Ethanol can also be produced by fermentation of cellulose-based material (switchgrass, pine trees). Ethanol from grasses or bagasse is now commercially available by the use of high temperature de-lignification of plant materials and the use of enzymes and special yeast that can use C-5 sugar and convert it to C-6 sugar or to ethanol. The use of wood i.e. pine trees, is still in its infancy because of the high cost of converting hardwood into easy-to-use material.
[0007] Eighty percent of the world's ethanol is produced by Brazil and the USA. Of this, 60% is produced by yeast fermentation of corn or sugar cane juice. Ethanol production through anaerobic fermentation of a carbon source by the yeast Saccharomyces cerevisiae is one of the best known biotechnological processes and accounts for more than 35 billion liters of ethanol per year worldwide (Bayrock, 2007).
[0008] Ethanol production from cereal grains begins with the hydrolysis of starch resulting in the conversion of amylose, a mostly linear α-D-(1-4)-glucan, and branched amylopectin, a α-D-(1-4)-glucan which has α-D-(1-6) linkages at the branch point, into fermentable sugars which are subsequently converted to ethanol by yeast (Majovic, 2006) or bacteria (Dien, 2003). Bacteria can convert cellulose-containing material into fermentable sugars for the production of ethanol; these include Zymomonas spp., genetically engineered E. coli, Klebsiella oxytoca, Zymomonas mobilis, Acetivibrio celluloyticus and others (Dien, 2003). Ethanol from sugarcane does not require the use of enzymes since yeast easily converts sucrose to ethanol and CO 2
[0009] Dry milling and wet milling are the two primary processes used to make ethanol from cereal grains in the United States. In the dry milling process, the entire corn ( Zea mays ) kernel or other starchy material is ground into flour and mixed with water to form a slurry. The mixture is then steam cooked to gelatinize the starch and decrease bacterial contamination. This mixture is then cooled and transferred to fermenters where yeast and enzymes are added to convert the sugars to ethanol. After fermentation, the resulting mixture is transferred to distillation columns where the ethanol is separated. The solids remaining after fermentation and ethanol separation are processed into distiller's dried grains with solubles (DDGS), which is used for animal production, e.g. poultry, swine, and cattle feed. More than 80% of today's ethanol capacity uses the dry mill process (RFS, 2006).
[0010] In wet milling the grain is soaked or steeped in water to facilitate separation of the grain into its basic nutritional components, such as corn germ, fiber, gluten and starch. After steeping, the corn slurry is processed through a series of grinders and the components are separated. The gluten component is filtered and dried to produce corn gluten meal (CGM), a high-protein product used as a feed ingredient in animal operations. The starch and any remaining water from the corn slurry are then processed in one of three ways: Fermented into ethanol, dried and sold as dried or modified corn starch, or processed into corn syrup (RFS, 2006). Both the wet and dry mill processes use only the starch portion of the corn kernel for ethanol production. The remaining protein, fat, fiber and other nutritional components remain available for use as animal feed.
[0011] A process called raw starch hydrolysis (dry grinding) converts starch to sugar which is then fermented to ethanol, bypassing conventional starch gelatinization conditions. The enzymes used in the saccharification/fermentation are fungal alpha amylase and glucoamylase (amyloglucosidase) (Thomas, 2001). This simultaneous saccharification and fermentation allows for higher concentrations of starch to be fermented and results in higher levels of ethanol (Maye, 2006).
[0012] Sugar cane, “ saccharuk officinarum” , is the cheapest raw material for renewable energy production. Comparing sugar cane and corn, the sugar cane can yield 5000-7000 liters/Ha/year of ethanol while corn's ethanol yield is 3000 liters/Ha/year (Lee and Bressa, 2006). Brazil and India are the main producers of ethanol from sugar cane. The production process begins with cultivating and harvesting sugarcane at a cane field. The cane is then processed at a sugar/ethanol mill, where cane stalks are washed with acidified water, then shredded and crushed to extract the cane juice. The bagasse, which is the resulting cane after the juice has been extracted, can be used to produce steam and generate electricity within the plant or sold to utility grids. In other mills, the cellulose from bagasse can be used to produce ethanol. After sugarcane juice is extracted it is transformed into alcohol through a fermentation process using yeasts as the catalyst. Sugar from sugarcane is readily available to yeast so fermentation requires only between 4 to 12 hours, compared to 72 hours for fermentation using cereal grains. Fermentation can be conducted in batches or continuously, using open or closed fermentation tanks. After fermentation, the sugarcane ethanol is distilled from other byproducts resulting in a level of purity of approximately 95%.
[0013] Another source for ethanol production is the sugar beet ,“ beta vulgaris. ” Sugar beet can be stored for one to three days, depending on the temperature and the method of storage, whereas sugar cane must be processed immediately after harvesting due to sugar losses. During the production of sugar from beet, slicing of the beet can cause some sugar to undergo breakdown to inverted sugar and then into acids, reducing sugar yields. In order to decrease bacterial action, it is known to use formaldehyde (50 to 100 ppm) and a pH adjustment. This method is used only during sugar production, not in a combined process of sugar and ethanol production. Arvanitis et al. (2004) suggests the use of formaldehyde or other cost effective disinfectant for the control of dextran produced by bacteria. Dextran inhibits crystallization of sugar. It also suggests controlling bacteria to preserve the sugar level if sugar beets are stored for long time. However all experimental data was from 7-day studies. Storage of sugar beets caused sugar levels to decrease due to bacterial contamination and dextran production. The reference teaches the use of 3.7% formaldehyde to store sugar beet longer to prevent bacterial contamination in sugar produced from sugar beet. There is no suggestion of using more concentrated formaldehyde (Arvantis et al. used 3.7% instead of 37%) for the production of ethanol from sugar beet. The MIC using formaldehyde was from 25-500 mg/lt. If the working solution is 3.7%, then the amount of formaldehyde added is only 0.925 mgr (25 mg/lt*0.037) to 18.5 mgr (500 mg/lt*0.037).
[0014] A variety of gram positive and gram negative bacteria have been isolated from fuel ethanol fermentation including species of Lactobacillus, Pediococcus, Staphylococcus, Enterococcus, Acetobacter, Gluconobacter and Clostridium (Bischoff, 2009). Almost two thirds of the bacteria isolated were species of lactic acid bacteria, e.g. Lactobacillus (Skinner, 2007). In sugar cane, Leuconostoc has been reported to negatively influence ethanol yield. The contamination of carbohydrate slurry during the course of alcoholic fermentation results in a) decreased ethanol yield, b) increased channeling of carbohydrates for the production of glycerol and lactic acids, c) a rapid loss of the yeast viability after exhaustion of fermentable sugars, and d) decreased proliferation of yeast in the corn slurry in which the contaminating Lactobacilli spp. have already grown to a high number (Thomas, 2001).
[0015] In a survey conducted by Skinner and Leathers (2004), 44-60% of the contaminants in the wet mill process were identified as Lactobacilli spp. In the dry mill process, 37 to 87% of the contaminants were identified as Lactobacilli spp. Another survey of bacterial contaminants of corn-based plants in the US found that bacterial loads in a wet mill facility were approximately 10 6 cfu/ml corn slurry while those at dry-grind facilities could reach 10 8 cfu/ml corn slurry (Bischoff, 2007; Chang, 1997).
[0016] Lactobacilli spp. contamination in the range of 10 6 to 10 7 cfu/mlml corn slurry can reduce ethanol yield by 1-3%. In industry, even with an active bacterial control program to control the proliferation of Lactobacilli spp., carbohydrate losses to Lactobacilli spp. can make the difference between profitability and non-profitability (Bayrock, 2007). Lactobacilli spp. not only tolerate low pH, high acidity and relatively high concentrations of ethanol, but they also multiply under conditions of alcoholic fermentation (Thomas, 2001). Bacterial contaminants compete for growth factors needed by yeast and also produce by-products that are inhibitory to yeast, particularly lactic and acetic acids.
[0017] The presence of Lactobacillus byproducts, i.e. acetic and lactic acids, during fermentation affects yeast growth and metabolism, and it has been suggested as one of the causes of stuck or sluggish fermentation (Thomas, 2001). If the lactic acid content of the corn slurry approaches 0.8% and/or acetic acid concentration exceeds 0.05%, the ethanol producing yeast are stressed (Bayrock, 2007). Lactobacilli spp. may stress yeast cells, which release nutrients, particularly amino acids and peptides that can stimulate bacterial growth (Oliva-Neto, 2004). A lactic acid concentration of 8 g/L in a beet molasses batch fermentation reduced yeast viability by 95% and alcohol production rate by 80% (Bayrock, 2001).
[0018] The presence of Lactobacillus in the ethanol fermentation can decrease ethanol yield by 44% after 4 days of pH controlled operation. This coincides with an increase in L. paracasei to >10 10 cfu/ml and a fourfold increase in lactic acid concentration to 20 g/L. An 80% reduction in yeast density was seen with concentrations of ethanol, lactic acid and acetic acid of 70, 38 and 7.5 g/L respectively (Bayrock, 2001).
[0019] De Oliva-Neto and Yokoya (1994) evaluated the effect of bacterial contamination on a batch-fed alcoholic fermentation process. They showed that L. fermentum will strongly inhibit commercial baker's yeast in a batch-fed process. When the total acid (lactic and acetic) exceeded 4.8 g/L it interfered with yeast bud formation and viability with 6 g/L decrease in alcoholic efficiency.
[0020] Others have shown that: a) a 10 6 Lactobacilli spp./ml corn slurry results in approx 1% v/v reduction in the final ethanol produced by yeast (Narendranath, 2004), b) challenging the fermentation system with 10 8 cfu L. fermentum /ml in the corn slurry decreased ethanol yield by 27% and increased residual glucose from 6.2 to 45.5 g/L (Bischoff, 2009), and c) the use of 10 5 cfu Lactobacilli spp./ml produced an 8% reduction in ethanol yield and a 3.2 fold increase in residual glucose (Bischoff, 2009).
[0021] Sugar cane depending on harvesting, storage and environmental conditions can suffer from Leuconostoc deterioration which resulted in a decrease in ethanol yield and increase formation of dextran (glucose polysaccharide) that inhibit crystallization of sugar. Leuconostoc is also present on sugar beet process (Eggleston et. al. 2008).
[0022] Conditions in the fermentation/liquidfication tanks are optimum for bacterial growth. Contamination generally originates from harvesting of the carbohydrate material. Washing the material may help lower the contamination level (Mayes, 2006). Other methods to control bacteria include the addition of more yeast culture, stringent cleaning and sanitation, acid washing of yeast destined for reuse, and the use of antibiotics during fermentation (Hynes, 1997). An increased yeast inoculation rate of 3×10 7 cfu/ml corn slurry resulted in greater than 80% decrease in lactic acid production by L. plantarum and greater than 55% decrease in lactic acid production by L. paracasei, when corn slurry was infected with 1×10 8 Lactobacilli spp./ml (Narendranath, 2004; Bischoff, 2009).
[0023] Currently, virginiamycin is the only approved antibiotic known to be used at the dry-grind plant (Bischoff, 2007). The recommended dose of virginiamycin in fuel ethanol fermentations is generally 0.25 to 2.0 ppm (Bischoff, 2009) but the Minimum Inhibitory Concentration (MIC) varies from 0.5 to greater than 64 ppm (Hynes, 1997).
[0024] Various agents have been tested for control of bacterial contaminants in laboratory conditions including antiseptics such as hydrogen peroxide, potassium metabisulfite, and 3,4,4′-trichlorocarbanilide and antibiotics such as penicillin, tetracycline, monensin and virginiamycin. Penicillin and virginiamycin are commercially sold today to treat bacterial infections of fuel ethanol fermentation and some facilities use these antibiotics prophylactically (Skinner, 2004).
[0025] If no antibiotics are used, a 1% to 5% loss in ethanol yield is common. A fifty million-gallon fuel ethanol plant operating with a lactic acid level of 0.3% w/w in its distiller's beer is losing approximately 570,000 gallons of ethanol every year due to bacterial contamination (Maye, 2006). In the absence of an antibiotic, bacterial numbers increased from 1×10 6 cfu/ml to 6×10 6 cfu/ml during a 48 hour fermentation period and 5.8 mg lactic acid was produced (Hynes, 1997).
[0026] A bacterial control program involves the use of virginiamycin. Some characteristics of virginiamycin are: a) it is effective against a number of microorganisms including Lactobacilli spp. at low concentrations, e.g., 0.3 to 5 ppm, b) the microorganisms do not tend to develop resistance, c) it does not significantly inhibit the yeast, d) it is not affected by the pH or alcohol concentration, and e) it is inactivated during ethanol distillation, therefore no residue remains in the alcohol or distilled grains (Bayrock, 2007; Narendranath, 2000; Hynes, 1997). Decreased susceptibility to virginiamycin has been observed in Lactobacilli spp. isolated from dry-grind ethanol plants that use virginiamycin, and the emergence of isolates with multi-drug resistance to both penicillin and virginiamycin has also been reported (Bischoff 2009).
[0027] L. fermentum could be selectively controlled by hydrogen peroxide at concentrations of 1 to 10 mM in an ethanol fermentation process (Narendranath, 2000). Lactobacillus does not have the enzyme catalase, so it cannot decompose hydrogen peroxide and therefore is unable to eliminate its toxic effect (Narendranath, 2000).
[0028] Urea hydrogen peroxide (UHP) has been used as an antiseptic for topical applications on wounds and against gingivitis and dental plaque (Narendranath, 2000) and also serves as an antibacterial during fermentation. UHP not only exhibits excellent bactericidal activity against Lactobacillus but also has an important advantage of providing usable nitrogen in the form of urea for stimulating yeast growth and fermentation rates (Narendranath, 2000).
[0029] Other methods of controlling bacterial contamination include the use of sulfites. Sulfites demonstrate bactericidal activity only in the presence of oxygen and were more effective in killing facultative L. casei which possess high levels of hydrogen peroxide related enzymes, including peroxidase (Chang, 1997). Bacterial load was also decreased when the concentration of sulfite ranged from 100 to 400 mg/L but only in the presence of oxygen. This concentration did not affect yeast populations (Chang, 1997).
[0030] An agent present in the supernatant of yeast cultures reduces the growth of Lactobacilli spp. This compound has not yet been characterized, though it is known to be resistant to freezing, unstable at high temperatures and destroyed when held at 90° C. for 20 minutes (Oliva-Neto 2004).
[0031] Succinic acid by itself at levels of 600 mg/L reduces Lactobacillus concentrations by 78%, in the presence of ethanol that reduction is up to 96% (Oliva-Neto 2004).
[0032] A microbial adherence inhibitor in the form of fowl egg antibodies and specific to lactic acid-producing microorganisms has been developed for use in fermenters (Nash 2009).
[0033] Laboratory studies have shown that antibodies, sulfite and peroxide products can be beneficial in controlling Lactobacilli spp., a problem with these products is the decrease in concentration due to oxidation and decomposition of the chemicals which will require constant monitoring of the whole process of fermentation in order to maintain an effective concentration.
[0034] U.S. Pat. No. 7,955,826 suggests the use of a monoterpene and a surfactant to improve production of ethanol. The monoterpene is d-limonene. The composition is added to the fermentation medium resulting in reduced cleaning requirements. The composition is a water/oil emulsion added to a level of 0.1-1000 ppm. It is also suggested to improve the viability of yeast and is added to corn fermentation media, the emulsion containing 1-70% d-limonene, 0.2-25% surfactant and the balance water.
[0035] To prevent sugar cane deterioration a combination of 8.6 ppm Nisin and 0.1% Tween 20 can be used to delay the lag phase of lactobacillus for 12 hours (Franchi et. al., 2006). The use of 10 ppm Kamoran (tade name of monensin) or a mixture of penicillin 10 ppm and tetracycline have been used to prevent sugar cane deterioration (Payot, 2004). In a related study, out of five commercially available antimicrobial products, only two containing formaldehyde (3.7%) or a quaternary ammonium-isopropanol (3.5%), showed similar effectiveness against lactic bacteria in sugar cane facilities (Arvanitis, et. al., 2004).
[0036] In a dry-grind fuel ethanol plant that uses virginiamycin, six strains of Lactobacillus fermentum, two strains of L. johnsonii and one strain of L. mucosae and L. amylovorus were found all around the fermentation system. It was suggested that biofilms may play a role in the persistence of contaminants in ethanol production facilities (Rich et. al. 2011).
[0037] Despite efforts to prevent contamination through cleaning and disinfecting saccharification tanks and continuous yeast propagation systems, biofilms can act as reservoirs of bacteria that continuously reintroduce contaminants (Bischoff, 2009). Biofilms can occur in many locations; in the human body, for example, they occur in gums, teeth, and ears and can be responsible for infections in that area. Biofilm cells are organized into structured communities enclosed in a matrix of extracellular material. They are phenotypically different from planktonic or suspended cells. They resist host defenses and display decreased susceptibility to antimicrobial agents (Berit et. al. 2002). Damaged lines or pipes that are abraded or scratched create surfaces where organisms can more easily attach. Biofilms are the source of much of the free-floating bacteria in drinking water and machinery, especially in pipes. Once bacteria colonize, they start forming a glycocalyx matrix that holds water, making a film of gelatinous and slippery consistency. This gel-like film encloses the microbial cell and may act as a barrier against the penetration of sanitizers and antimicrobials (Perez-Conesa, et.al. 2006). A review of microbial biofilms can be found in Davey and O'Toole (2000).
[0038] Several US patents describe products to control biofilms. U.S. Pat. No. 6,830,745 teaches using a couple of enzymes systems, one which disrupts biofilm structure and another having a bactericidal effect. U.S. Pat. No. 8,012,461 teaches a biofilm remover which is an aqueous solution containing a quaternary halide surfactant and a source of bromide ions. U.S. Pat. No. 7,165,561 discloses an enzyme and surfactant to decrease and inhibit the growth of biofilms in crossflow filtration systems. US Published Application No. 2011/0123462 discloses the use of unsaturated long chain alcohols and/or aldehydes for the disruption of biofilms, the solutions containing 0.005% to 5% of the active ingredient, preferably 0.05% and 22% ethanol and 77% water.
[0039] Controlling the formation of biofilms is important to do throughout the fermentation system, from cutting the sugar cane or sugar beet all the way through the final product. The present invention can be used during all of these steps of ethanol fermentation. In the case of sugar cane, it can be added to the first juice obtained after cutting and pressing the cane. It can be used during the transferring of juice to the cooling area. It can be used when mixing the juice to obtain the right sugar concentration before going to the fermentation vessel. It can be used while filling up the fermentation vessel with juice or in combination with the yeast broth. Other points of addition for the present invention can be used with the same results, i.e. improved ethanol yield by controlling biofilms. The present invention can prevent the formation of biofilms as well as disrupt established biofilms.
REFERENCES
[0040] Arvanitis, N., C. Z. Kotzamanidis, G. N. Skaracis and A. D. Karagouni. The effectiveness of commercial antimicrobial compounds against saccharolytic microorganisms isolated from beet sugar production line. World J. Microbiology & Biotechnology 2004, 20: 291-296.
[0041] Bayrock, D., 2007. Method of reducing the growth of lactobacillus in a process of ethanol production by yeast fermentation comprising adding a pristinamycin type antimicrobial agent and/or a polyether ionophore antimicrobial agent dissolved in an organic solvent. PCT patent # WO 2007/145858
[0042] Bayrock, D. P., K. C. Thomas and W. M. Ingledew. Control of Lactobacillus contaminants in continuous fuel ethanol fermentations by constant or pulsed addition of penicillin. G. App. Microbiol. Biotechnol 2003, 62: 498-502.
[0043] Bayrock, D. and W. M. Ingledew. Changes in steady state on introduction of a lactobacillus contaminant to a continuous culture ethanol fermentation. J. Industrial Microbiology and Biotechnology 2001, 27: 39-45.
[0044] Berit, A. G. S. Baillie and L. J. Douglas. Mixed species biofilms of Candida albicans and Staphylococcus epidermis. J. Med Microbiol 2002, 51: 344-349.
[0045] Bischoff, K. M., S. Liu, T. D. Leathers and R. E. Worthington. Modeling bacterial Contamination of Fuel Ethanol Fermentation. Biotechno. Bioeng. 2009, 103: 117-122.
[0046] Bischoff, K. M., K. A. Skinner-Nemec and T. D. Leathers. Antimicrobial susceptibility of Lactobacillus species isolated from commercial ethanol plants. J. Ind. Microbiol. Biotechnol. 2007
[0047] Chang I. N., B. H. Kim and P. K. Shin. Use of sulfite and hydrogen peroxide to control bacterial contamination in ethanol fermentation. Applied and Environmental Microbiology 1997, 63(1): 1-6.
[0048] Davey, W. E. and G. A. O'Toole. Microbiology and Molecular Biology Reviews 2000, 64(4): 847-867.
[0049] Dien, B. S., M. A. Cotta and T. W. Jeffries. Bacteria engineered for fuel ethanol production: current status. Appl. Microbiol. Biotechnol. 2003, 63: 258-266.
[0050] Eggleston, G., M., P. G. Moerl Du Boil and S. N. Waldford. A review of sugar cane deterioration in the United States and South Africa. Proc. S. Afr. Sug. Technol. Ass. 2008, 81: 72-85.
[0051] Franchi, M. A., G. E. Serra and M. Cristianini. The use of biopreservatives in the control of bacterial contaminants of sugarcane alcohol fermentation. 2006, 68(7):2310-2315.
[0052] Hynes, S. H., Kjarsgaard, K. C. Thomas and W. M. Ingledew. Use of virginiamycin to control the growth of lactic acid bacteria during alcohol fermentation. J Industrial Microbiology and Biotechnology 1997, 18: 284-291.
[0053] Lee T. S. G. and E. A. Bressan. Sugar Tech 2006, 8(4): 195-196.
[0054] Majovic, L, S. Nikolic, M. Rakin and M. Vukasinovic. Production of Bioethanol from Corn Meal Hydrolyzates. Fuel 2006, 85: 1750-1755.
[0055] Maye, John P., 2006. Use of hop acids in fuel ethanol production. US patent application #20060263484
[0056] Narendranath, N. V. and R. Power. Effect of yeast inoculation rate on the metabolism of contaminant Lactobacilli spp. during fermentation of corn corn slurry. J. Ind. Microbiol. Biotechnol. 2004, 31: 581-584.
[0057] Narendranath, N. V., K. C. Thomas and W. M. Ingledew. Urea hydrogen peroxide reduces the number of Lactobacilli spp., nourish yeast, and leaves no residues in the ethanol fermentation. Applied and Environmental Microbiology 2000, 66(10): 4187-4192.
[0058] Nash, P. 2009. Immunogen adherence inhibitor directed to lactobacillus organisms and method of making and using it. United States Patent Application #20090117129
[0059] Oliva-Neto, P., M. A. Ferreira and F. Yokoya. Screening for yeast with antibacterial properties from ethanol distillery. Bioresource Technology 2004, 92: 1-6.
[0060] Payot, T. 2004. Kamoran using in sugar beet production to improve the quality of diffusion step UNGDA, www.ungda.com.
[0061] Perez-Conesa, D., L Mclansboough and J. Weiss. Inhibition and inactivation of Listeria monocytogenes and Escherichia coli O157:H7 colony biofilms by micellar-encapsulated eugenol and carvacrol. J. Food Protection 2006, 69(12): 2947-2954.
[0062] Rich, J. O., T. D. Leathers, M. S. Nunnally and K. M. Bischoff. Rapid evaluation of the antibiotic susceptibility of fuel ethanol contaminant biofilms. Bioresource Technology 2011, 102: 1124-1130.
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[0064] Skinner-Nemec, K. A., N. N Nichols and T. D. Leathers. Biofilm formation by bacterial contaminants of fuel ethanol production. Biotechnol. Lett. 2007, 29: 379-383.
[0065] Skinner, K. A. and T. D. Leathers. Bacterial Contaminants of Fuel Ethanol Production. J. Ind. Microbiol. Biotech. 2004, 31: 401-408.
[0066] Thomas, K. C., S. H. Hynes and W. M. Ingledew. Effect of Lactobacilli spp. on yeast growth, viability and batch and semi-continuous alcoholic fermentation on corn corn slurry. J. Applied Microbiology 2001, 90: 819-828.
SUMMARY OF THE INVENTION
[0067] An object of the invention is to provide a chemical composition that prevents and/or disrupts biofilm formation during ethanol production, by reducing or not allowing establishment of bacteria on solid surfaces.
[0068] Another object is to A high yield method of fermenting carbohydrate to ethanol in a fermentor, comprising:
[0069] a) mixing a fermentation feedstock with a fermentation broth containing yeast and/or an enzyme,
[0070] b) treating said mixture by adding a composition to the fermentor containing:
10-90 wt. % of an aldehyde selected from the group consisting of formaldehyde, para-formaldehyde, glutaraldehyde, another antimicrobial aldehyde, and mixtures thereof, 1-50 wt. % of a surfactant having an HLB from 4 to 18, 0-20 wt. % of an antimicrobial terpene, or essential oils, 1-50 wt. % of organic acids selected from C 1 to C 24 fatty acids, their salts, glycerides and esters thereof, and 1-50 wt. % water;
wherein the concentration of aldehyde in the fermentor is from about 0.25 to 3 kg/MT of fermentation feedstock, and
[0077] c) isolating ethanol.
[0078] Another object is to provide a fermentation broth or slurry, comprising:
[0079] a) carbohydrate feedstock to be fermented, yeast, and/or an enzyme, and
[0080] b) a treatment composition containing:
10-90 wt. % of an aldehyde selected from the group consisting of formaldehyde, para-formaldehyde, glutaraldehyde, another antimicrobial aldehyde and mixtures thereof, 1-50 wt. % of a surfactant having an HLB from 4 to 18, 1-20 wt. % of an antimicrobial terpene, or essential oils, 1-50 wt. % of organic acids selected from C 1 to C 24 fatty acids, their salts, glycerides and esters thereof, and 1-50 wt. % water;
wherein the concentration of aldehyde is from about 0.25 to 3 kg/MT of fermentation feedstock.
[0087] Another object is to provide an improved method of fermenting carbohydrate to ethanol in a fermentor, comprising:
[0088] a) mixing a fermentation feedstock with a fermentation broth containing yeast and/or an enzyme,
[0089] b) treating said mixture by adding a composition to the fermentor containing:
10-90 wt. % of an aldehyde selected from the group consisting of formaldehyde, para-formaldehyde, glutaraldehyde, another antimicrobial aldehyde, and mixtures thereof, 1-50 wt. % of a surfactant having an HLB from 4 to 18, 0-20 wt. % of an antimicrobial terpene, or essential oils, 1-50 wt. % of organic acids selected from C 1 to C 24 fatty acids, their salts, glycerides and esters thereof, and 1-50 wt. % water;
wherein the concentration of aldehyde in the fermentor is from about 0.25 to 3 kg/MT of fermentation feedstock, and
[0096] c) isolating ethanol,
[0097] d) collecting material remaining after fermentation and adding it to animal feed.
[0098] Another object of the invention is to provide a method for preventing biofilms formation during the entire process of ethanol production by adding a composition to the liquid slurry or fermentable broth comprising:
[0099] a) 10-90 wt.% of an aldehyde selected from the group consisting of formaldehyde, para-formaldehyde, glutaraldehyde, other antimicrobial aldehyde and mixtures thereof,
[0100] b) 1-50 wt. % of a surfactant having an HLB from 4 to 18,
[0101] c) 1-20 wt. % of an antimicrobial terpene, or essential oils,
[0102] d) 1-50 wt % of organic acids selected from C 1 to C 24 fatty acids, their salts, glycerides and esters thereof, and
[0103] e) 1-50 wt % water,
[0104] wherein the concentration of aldehyde in the fermentor is from about 0.25 to 3 kg/MT of fermentation feedstock.
[0105] Another object of the invention is to provide a method for disrupting already established biofilms on the entire equipment used for ethanol production by adding a composition to the liquid slurry or fermentable broth comprising:
[0106] a) 10-90 wt. % of an aldehyde selected from the group consisting of formaldehyde, para-formaldehyde, glutaraldehyde, other antimicrobial aldehyde and mixtures thereof,
[0107] b) 1-50 wt. % of a surfactant having an HLB from 4 to 18,
[0108] c) 1-20 wt. % of an antimicrobial terpene, or essential oils,
[0109] d) 1 -50 wt % of organic acids selected from C 1 to C 24 fatty acids, their salts, glycerides and esters thereof, and
[0110] e) 1-50 wt % water,
[0111] wherein the concentration of aldehyde in the fermentor is from about 0.25 to 3 kg/MT of fermentation feedstock.
[0112] Another object of the invention is to reduce the use of antibiotics and sulfuric acid during the fermentation of carbohydrates adding to the fermentation system a composition comprising:
[0113] a) 10-90 wt. % of an aldehyde selected from the group consisting of formaldehyde, para-formaldehyde, glutaraldehyde, other antimicrobial aldehyde and mixtures thereof,
[0114] b) 1-50 wt. % of a surfactant having an HLB from 4 to 18
[0115] c) 1-20 wt. % of an antimicrobial terpene, or essential oils,
[0116] d) 1-50 wt % of organic acids selected from C 1 to C 24 fatty acids, their salts, glycerides and esters thereof, and
[0117] e) 1-50 wt % water,
[0118] wherein the concentration of aldehyde in the fermentor is from about 0.25 to 3 kg/MT of fermentation feedstock.
[0119] Another object of the invention is to reduce the antibiotic presence in the resulting sub-product of carbohydrates fermentation e.g. distilled grains, corn gluten and others.
[0120] Another object is to reduce antibiotic residues in animal products by feeding the animals sub-products of fermentation resulting from non-antibiotics but the present invention treated substrates.
[0121] Another object is to inhibit the development of antibiotic-resistant strains of bacteria which occur during fermentation.
[0122] Another object is to increase the yield of ethanol from fermented carbohydrate.
[0123] Another object is to improve yeast viability by decreasing the used of sulfuric acid and yeast prewash to decrease bacteria level.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Definitions
[0124] “Weight percent” (wt. %) of a component is based on the total weight of the formulation or composition in which the component is included.
[0125] “Aldehyde” includes formaldehyde, paraformaldehyde, and other biocidal aldehydes.
[0126] “Organic acid” includes formic, acetic, propionic, butyric and other C 1 to C 24 fatty acids, or mono-, di-, or triglycerides of C 1 to C 24 organic fatty acids or their alkyl esters.
[0127] “Antimicrobial terpene” can include allyl disulfide, citral, pinene, nerol, geraniol, carvacrol, eugenol, carvone, anethole, camphor, menthol, limonene, farnesol, carotene, thymol, borneol, myrcene, terpenene, linalool, or mixtures thereof. More specifically, the terpenes may comprise allyl disulfide, thymol, citral, eugenol, limonene, carvacrol, and carvone, or mixtures thereof. The terpene component may include other terpenes with anti-microbial properties and essential oils.
[0128] Bacteria that may interfere with ethanol fermentation include Lactobacillus spp. and Leuconostoc spp., which cause the most problems. Other such bacteria include Pediococcus spp., Staphylococcus spp., Streptococcus spp., Bacillus spp. and Clostridia spp. and other bacteria which reduce fermentation efficiency.
[0129] In ethanol produced from corn, antibiotics are the common biocide, e.g., virginiamycin, penicillin, clindamycin, tylosin, chloramphenicol, cephalosporin and tetracycline. However, because the end product is not fed to animals when ethanol is produced from sugarcane, other biocides can be used since residues do not present the same problem. In such cases suitable biocides include carbamates, quaternary ammonium compounds, phenols and antibiotics (e.g., virginiamycin, penicillin, clindamycin, tylosin, chloramphenicol, cephalosporin and tetracycline).
[0130] The term “effective amount” of a compound means an amount capable of performing the function or having the property for which the effective amount is expressed, such as a non-toxic but sufficient amount to provide anti-microbial benefits in a biofilm preventer or disrupter. Thus an effective amount may be determined by one of ordinary skill in the art by routine experimentation.
[0131] Formulations vary not only in the concentrations of the major components, e.g., aldehydes and organic acids, but also in the type of terpenes, surfactant(s) and water concentration. This invention can be modified by adding or deleting the terpene, type of organic acid, and using other types of surfactant.
Composition(s)
[0132] In general, a composition of the invention contains:
[0133] a) 10-90 wt.% of an aldehyde selected from the group consisting of formaldehyde, para-formaldehyde, glutaraldehyde, other antimicrobial aldehyde and mixtures thereof,
[0134] b) 1-50 wt. % of a surfactant having an H LB from 4 to 18,
[0135] c) 1-20 wt. % of an antimicrobial terpene, or essential oils,
[0136] d) 1-50 wt. % of an organic acid or mixtures of organic acids selected from acetic, propionic, butyric, or other C 1 to C 24 fatty acids, salt forms, glycerides and esters thereof, and,
[0137] e) 1-50 wt % water.
[0138] The antimicrobial terpenes, plant extracts or essential oils containing terpenes can be used in the compositions of this invention as well as the more purified terpenes. Terpenes are readily available commercially or can be produced by methods known in the art, such as solvent extraction or steam extraction/distillation or chemical synthesis.
[0139] The surfactant is non-ionic including ethoxylated castor oil surfactants with 1 to 200 ethylene molecules distributed normally around the mean, preferably a mean of 10 to 80. Other surfactants with similar characteristics can be used including polysorbates surfactants.
Methods
[0140] The present invention is effective against bacteria and bacterial biofilms. Examples of such infective agents include, E. coli, Salmonella spp., Clostridium spp., Campylobacter spp., Shigella spp., Brachyspira spp., Listeria spp., Arcobacter spp, Lactobacillus, Pediococcus, Staphylococcus, Enterococcus, Acetobacter, Gluconobacter, A. pasterurianus, B. Subtilis, Leuconostoc mesenteroides, Weissella paramesenteroides and others.
[0141] The mixture of the present invention is applied by a spray nozzle.
[0142] The mixture of the present invention is applied mixed with a soluble carrier to the fermentable carbohydrate.
[0143] The mixture of the present invention is applied mixed in a starch-based carrier to the fermentable carbohydrate.
[0144] The mixture of the present invention is mixed with a liquid or solid carrier prior to be added to the fermentable carbohydrate.
[0145] The mixture of the present invention is applied drop-wise on the fermentable broth or slurry.
[0146] The mixture of the present invention is applied by inline injection to the fermentable broth or slurry.
[0147] The mixture of the present invention is applied in any or all of the treatable areas during production of sugar and ethanol from sugarcane.
[0148] The mixture of the present invention is applied in any or all of the treatable areas during production of sugar and ethanol from sugar beet.
[0149] The mixture of the present invention is applied in any or all of the treatable areas during production of sugar and ethanol from corn, other starchy or cellulosic material.
[0150] The mixture is applied so as to provide a uniform and homogeneous distribution throughout the carbohydrate substrate.
[0151] Various patents and publications are referenced throughout this specification. The disclosures of each document are hereby incorporated by reference in their entirety.
EXAMPLE 1
[0152] This example shows the base formulation “A” product used in subsequent examples
[0000]
TABLE 1
Components of Formulation “A”
Ingredient
(%)
Formalin (37%)
90.00
Propionic Acid
9.00
d-limonene (terpene)
0.40
Polysorbate 80 (surfactant)
0.60
EXAMPLE 2
[0153] The objective of this study was to determine the effect of a Formula “A” on the survival of Lactobacillus. Lactobacillus plantarum (B-4496) obtained from USDA-Microbial Genomics and Bioprocessing Research in Illinois was grown in Difco™ Lactobacilli spp. MRS (Man-Rogosa-Sharpe) broth. The broth culture was diluted with sterile peptone water to obtain different concentrations of Lactobacillus. Dilutions were treated with different concentrations of Formula A (0, 1, 2 and 3 kg/MT) and incubated for 24 hours at room temperature (20° C.). After incubation, triplicate samples were taken and plated on MRS broth containing 1.5% Difco™ Agar Granulated solidifying agent. Plates were incubated at 37° C. for 24 hours before enumeration of colonies. The average cfu/ml for each treatment is shown in Table 2.
[0000]
TABLE 2
Effect of Formula “A” in the Growth of Lactobacillus
(cfu/ml)
Control (0 kg/MT)
4.1 × 10 7
4.8 × 10 6
5.2 × 10 5
4.8 × 10 4
3.3 × 10 2
5.3 × 10 1
4.0
1 kg/MT
5.0 × 10 7
1.2 × 10 6
8.6 × 10 5
7.9 × 10 3
0
0
0
2 kg/MT
0
0
0
0
0
0
0
3 kg/MT
0
0
0
0
0
0
0
[0154] It was observed that the use 2 kg/MT of the Formula “A” eliminated the growth of Lactobacillus in a culture containing 10 7 cfu/ml.
EXAMPLE 3
[0155] The objective of this study was to determine the effect of Formula “A” on the survival of yeast and Lactobacillus during fermentation. Sterile, finely ground corn was mixed with sterile water in a glass fermenter. Next, a commercial enzyme solution containing alpha-amylase and glucoamylase blend (Stargen: Genencor) for processing of uncooked starch was added. Fali Yeast (10 10 cfu/g; Fleischmann) used as fermentative yeast was added to the corn slurry mixtures while mixing. Finally, Lactobacillus plantarum (B-4496), obtained from USDA-Microbial Genomics and Bioprocessing Research in Illinois and grown in Difco™ Lactobacilli spp. MRS broth, was used as the representative bacterial contaminant of the fermenter. Formula “A” at a dose of 1 Kg/MT was added as the final step before starting the fermentation process. Samples of the liquid phase taken at 4 h, 24 h, 48 h, 72 h and 96 hours were analyzed for yeast and lactobacillus counts. The results are shown in the following tables:
[0000]
TABLE 3
Effect of Formula “A” on Yeast
Counts During Fermentation (cfu/ml)
4 h
24 h
48 h
72 h
96 h
Control
6.8 × 10 8
1.8 × 10 9
2.3 × 10 8
8.0 × 10 8
8.0 × 10 11
Formula A
7.9 × 10 8
2.3 × 10 9
4.8 × 10 8
8.0 × 10 8
2.0 × 10 9
(1 kg/MT)
[0000]
TABLE 4
Effect of Formula “A” on Lactobacillus
Counts During Fermentation (cfu/ml)
4 h
24 h
48 h
72 h
96 h
Control
7.6 × 10 5
1.6 × 10 8
1.3 × 10 9
2.9 × 10 12
2.2 × 10 8
Formula A
6.4 × 10 5
6.8 × 10 7
1.6 × 10 9
1.6 × 10 12
9.0 × 10 7
(1 kg/MT)
[0156] It was observed that 1 kg/ton of the formaldehyde-based product decreased the level of Lactobacillus, but did not affect the level of yeast.
EXAMPLE 4
[0157] The objective of this study was to determine if changes in Formula “A” resulted in similar benefits as previous examples. Fermentation solution was free of Lactobacillus. Formula “A” was modified as described in Table 5. This example was also conducted as to simulate sugar cane fermentation.
[0000]
TABLE 5
Changes compared to Formula “A”
A
B
C
D
E
Formaldehyde (37%)
90
90
90
90
90
Propionic acid
9
9
8
5
0
d-limonene
0.4
0
0
0
0
Polysorbate 80
0.6
1
2
5
10
[0158] In 250-ml glass fermentors, 100 ml of a 12% sterile sucrose solution, 10 ml yeast (10 6 cfu/ml) and 25 ul of each formulation were added and incubated for 24 hours. After incubation, samples were taken for the determination of ethanol yield. The results are shown on Table 6.
[0000]
TABLE 6
Effect of Different Formulations on Ethanol Yield (% Ethanol)
Control
5.97 ± 0.10 x
Formula “A”
5.59 ± 0.00 y
Formula “B”
5.66 ± 0.06 xy
Formula “C”
5.84 ± 0.30 xy
Formula “D”
5.80 ± 0.06 xy
Formula “E”
5.94 ± 0.00 xy
[0159] When there is no bacterial competition during fermentation, the concentration of ethanol was similar in all treatments with the exception of Formula A.
EXAMPLE 5
[0160] The objective of this study was to determine if changes in Formula “A” resulted in similar benefits as shown on previous examples. In this example, Lactobacillus was added to the fermentors to simulate naturally occurring Lactobacillus. The same formulations as Example 4 were used. In 250-ml glass fermentors, 100 ml of a 12% sterile sucrose solution, 10 ml yeast (10 6 cfu/ml) and 25 ul of each formulation were added and incubated for 24 hours. After incubation samples were taken for the determination of ethanol yield as well as yeast and lactobacillus. The results are shown on table 7.
[0000]
TABLE 7
Effect of Effect of Different Formulations
on Ethanol Yield and Microbial Profile
% ethanol
Formulations
Yeast
Lactobacillus
(mean ± S.D.)
Control
1.45 × 10 8
1.20 × 10 8
6.18 ± 0.38 xy
Formula “A”
1.08 × 10 8
1.13 × 10 8
6.38 ± 0.15 xy
Formula “B”
9.78 × 10 7
1.16 × 10 8
6.28 ± 0.50 xy
Formula “C”
7.30 × 10 7
1.01 × 10 8
6.67 ± 0.20 x
Formula “D”
8.12 × 10 7
7.77 × 10 7
5.06 ± 0.02 y
Formula “E”
8.20 × 10 7
9.97 × 10 7
5.49 ± 0.37 xy
[0161] It was observed that formulas A, B and C resulted in a numerical improvement in ethanol yield in the presence of bacterial completion when fermentation lasted 24 hours.
EXAMPLE 6
[0162] The objective of this study was to determine if changes in Formula “A” resulted in similar benefits as shown in previous examples. In this example, Lactobacillus was added to the fermentors to simulate naturally occurring Lactobacillus. The same formulations as Example 4 were used. In 250-ml glass fermentors, 100 ml of a 12% sterile sucrose solution, 10 ml yeast (10 6 cfu/ml) and 25 ul of each formulation were added and then incubated for 18 hours. After incubation, samples were taken for the determination of ethanol yield as well as yeast and lactobacillus. The results are shown in Table 8.
[0000]
TABLE 8
Effect of Effect of Different Formulations
on Ethanol Yield and Microbial Profile
% ethanol
Formulations
Yeast
(mean ± S.D.)
Control
1.27 × 10 8
5.41 ± 0.16 xy
Formula “A”
1.11 × 10 8
5.11 ± 0.12 y
Formula “B”
1.08 × 10 8
5.14 ± 0.08 y
Formula “C”
1.23 × 10 8
5.37 ± 0.15 xy
Formula “D”
1.27 × 10 8
5.56 ± 0.31 x
Formula “E”
1.34 × 10 8
5.22 ± 0.07 y
[0163] It was observed that formula D resulted in an improvement in ethanol yield in the presence of bacterial completion when fermentation lasted 18 hours.
EXAMPLE 7
[0164] The objective of this example was to determine the effect of the using Formula “A” on the destruction of biofilms using lactobacillus as the biofilm forming bacteria. Formula “A” was added at a dose of 0.5 or 1 Kg/MT. The formation of biofilms was prepared as follows:
[0165] In 96-well polystyrene plates: 100 μl of Lactobacillus culture in nutrient broth was added to each well and incubated for 48 hours at 37° C. in an anaerobic chamber. After incubation the plates were washed 5 times with distilled water and blotted dry. After drying, 100 ul of formulation “A” was added to the wells, incubated for 4 or 24 hours at 37° C. in an anaerobic chamber and then washed 5 times with distilled water. After blotting dry, 30 μl of 1% crystal violet was added then incubated for 15 minutes at room temperature to allow the dyeing of biofilms. Wells were washed 5 times with distilled water, blotted dry, 200 μl of 95% ethanol was added and then the plates were read at 590 nm. Results are expressed as the % difference between O.D. of control and the treated samples.
[0000]
TABLE 9
Biofilms Destruction when Exposed for 4 hours
O.D.
% Destruction
Control
0.746
—
0.5 Kg/MT
0.547
27
[0000]
TABLE 10
Biofilms Destruction when Exposed for 4 hours
O.D.
% Destruction
Control
0.803
—
1.0 Kg/MT
0.691
14
[0000]
TABLE 11
Biofilms Destruction when Exposed for 24 hours
O.D.
% Destruction
Control
0.396
—
0.5 Kg/MT
0.344
13
1.0 Kg/MT
0.312
20
[0166] Both dosifications of Formula “A” resulted in a partial destruction of established biofilms.
EXAMPLE 8
[0167] The objective of this example was to determine the effect of the formulas from Example 4 on the destruction of biofilms using Lactobacillus as the biofilm forming bacteria. All formulas were added at a dose of 1 Kg/MT. The formation of biofilms was prepared as follows:
[0168] In 96-well polystyrene plate: 100 μl of Lactobacillus culture in nutrient broth was added to each well and incubated for 48 hours at 37° C. in an anaerobic chamber. After incubation the plates were washed 5 times with distilled water and blotted dry. After drying, 100 ul of each formulation were added to the wells, the plates incubated for 4 hours at 37° C. in an anaerobic chamber and then washed 5 times with distilled water. After blotting dry, 30 μl of 1% crystal violet was added and the plates incubated for 15 minutes at room temperature to allow the dyeing of the biofilm. Wells were washed 5 times with distilled water, blotted dry, 200 μl 95% ethanol was added and then the plates were read at 590 nm. Results are expressed as the % difference between O.D. of control and the treated samples.
[0000]
TABLE 12
Biofilms Destruction when Exposed for 4 hours
O.D.
% Destruction
Control
0.076
—
Formula “A”
0.052
32
Formula “B”
0.055
28
Formula “C”
0.055
28
Formula “D”
0.051
33
Formula “E”
0.051
33
[0169] All formulations were effective against established biofilms.
EXAMPLE 9
[0170] The objective of this example was to determine the effect of the formula “A” cited in the previous examples on the prevention of biofilms formation using Lactobacillus as the biofilm forming bacteria. Formula “A” was added at a dose of 0.5 and 1 Kg/MT. The prevention of biofilms formation was prepared as follows:
[0171] In 96-well polystyrene plate: 100 μl of Lactobacillus culture in nutrient broth and 100 ul of each formula “A” at a dose of 0.5 or 1.0 Kg/MT were added to the wells and incubated for 48 hours at 37° C. in an anaerobic chamber. After incubation the plates were washed 5 times with distilled water and blotted dry. After blotting dry, 30 μl of 1% crystal violet was added, then the plates were incubated for 15 minutes at room temperature to allow the dyeing of biofilms. Wells were washed 5 times with distilled water, blotted dry, 200 μl 95% ethanol was added and then the plates were read at 590 nm. Results are expressed as the % difference between O.D. of control and the treated samples.
[0000]
TABLE 13
Biofilms Prevention when Exposed for 48 hours
O.D.
% Prevention
Control
0.775
—
0.5 Kg/MT
0.674
13
1.0 Kg/MT
0.264
66
[0172] Formula “A” at both doses reduced the establishment of biofilms, with 1 Kg/MT being more effective than 0.5 Kg/MT.
EXAMPLE 10
[0173] The objective of this example was to determine the effect of the formulas from Example 4 on the prevention of biofilms formation using Lactobacillus as the biofilm forming bacteria. All formulas were added at a dose of 1 Kg/MT. The prevention of biofilms formation was prepared as follows:
[0174] In 96-well polystyrene plate: 100 μl of Lactobacillus culture in nutrient broth and 100 ul of each formula at a dose of 1.0 Kg/MT were added to the wells and incubated for 36 hours at 37° C. in an anaerobic chamber. After incubation the plates were washed 5 times with distilled water and blotted dry. After blotting dry, 30 μl of 1% crystal violet was added then incubated for 15 minutes at room temperature to allow the dyeing of biofilms. Wells were washed 5 times with distilled water, blotted dry, 200 μl 95% ethanol was added and then the plates were read at 590 nm. Results are expressed as the % difference between O.D. of control and the treated samples.
[0000]
TABLE 14
Biofilms Prevention when Exposed for 48 hours
O.D.
% Prevention
Control
0.113
—
Formula “A”
0.094
17
Formula “B”
0.093
18
Formula “C”
0.073
35
Formula “D”
0.077
32
Formula “E”
0.079
30
[0175] All formulas decreased the establishment of biofilms.
EXAMPLE 11
[0176] The objective of this example was to determine ethanol production using Formula “A” treated corn or Formula “A” added into the fermenters.
[0177] Whole corn was treated with zero (control) or 0.50 kg/MT, and stored overnight before grinding and setting the fermentation procedure. Treated and un-treated ground corn were mixed with water and incubated at room temperature in an anaerobic environment for 6 hours. Formulation A was added to the fermenters before the 6 hour incubation. The other reagents were added in the fermenters as described in the following.
[0000]
Corn
Water
Enzyme
Yeast
Treatment
(gr)
(ml)
(ml)
(10 8 cfu/gr)
Control - 0 kg/MT
30
100
0.20
1.0 gr
Formulation A - 0.50 kg/MT
30
100
0.20
1.0 gr
Formulation A - 30
30
100
0.20
1.0 gr
ul at fermenter,
(0.50/MT of corn)
[0178] Yeast was hydrated with lukewarm water at 1 gr/10 ml prior to adding to fermenters. Fermenters were kept under constant stirring (low speed) at room temperature for 72 hours before sampling for yeast and alcohol production. After 72 hours, triplicate samples/fermenter were taken and plated on PDA for the determination of yeast count. Plates were incubated at 27° C. for 48 hours and colonies enumerated.
Results:
[0179]
[0000]
Yeast
%
Treatment
(cfu/gr)
ethanol
Control
8.69 × 10 8
9.95 ± 0.13
Formula “A” treated corn
8.13 × 10 8
10.60 ± 0.89
Formula “A” treatment at
7.94 × 10 8
12.05 ± 0.16
fermentors
[0180] The addition of Formulation A in the fermenters improved ethanol yield as compared to Formula “A” treated corn.
[0181] It will be apparent to those skilled in the art that variations and modifications of the invention can be made without departing from the spirit and scope of the teachings above.
[0182] It is intended that the specification and examples be considered as exemplary only and are not restrictive.
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A high yield method for fermenting carbohydrate to ethanol and prevention and/or disruption of biofilms, comprising: a) mixing a fermentation feedstock with a fermentation broth containing yeast and/or an enzyme, b) treating said mixture by adding a composition to the fermentor containing: 10-90 wt. % of an aldehyde selected from the group consisting of formaldehyde, para-formaldehyde, glutaraldehyde, another antimicrobial aldehyde, and mixtures thereof, 1-50 wt. % of a surfactant having an HLB from 4 to 18, 0-20 wt. % of an antimicrobial terpene, or essential oils, 1-50 wt. % of organic acids selected from Ci to C24 fatty acids, their salts, glycerides and esters thereof, and 1-50 wt. % water; wherein the concentration of aldehyde in the fermentor is from about 0.25 to 3 kg/MT of fermentation feedstock, and c) isolating ethanol.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a divisional of U.S. application Ser. No. 10/521,072 filed Jan. 13, 2005, now U.S. Pat. No. 7,174,637, filed under 35 U.S.C. § 371 as a national phase entry of International Application No. PCT/GB2003/002640 on Jun. 20, 2003.
FIELD
The present invention relates to plain journal bearings, particularly though not exclusively, for internal combustion engines and to so-called overlay coatings deposited upon the running sliding surface of such bearings.
BACKGROUND
Overlay coatings on plain journal bearings are well known. Such coatings are used to improve the running characteristics of plain bearings. Generally, overlay coatings are relatively soft metal alloys having a hardness in the region of about 15 Hv; are frequently based on alloys of lead; and, are deposited on another harder bearing alloy at a thickness in the range from about 10 to 30 μm. Overlay alloys of the type under consideration are usually applied by electro-deposition from aqueous plating solutions.
The bearings on which the overlays are deposited are of generally cylindrical or, more commonly, semi-cylindrical form as half-bearing shells which support the crankshaft journals of internal combustion engines, for example. Such bearings generally comprise a layer of a strong backing material such as steel, for example, on which is bonded a layer of a bearing material frequently chosen from alloys of aluminium or copper. The method of attaching the layer of bearing alloy to the strong backing may be any that is suitable and may include techniques such as pressure welding of sheets of bearing alloy to the backing; the casting of molten alloy onto the backing; or, the sintering of powders of alloy to the backing, for example, these methods not being exhaustive. The overlay alloy coating is deposited on the surface of the harder bearing alloy and endows the finished bearing so formed with properties which include conformability and the ability to embed dirt particles and so prevent scoring of a shaft journal by particles of debris carried in the lubricating oil. Although overlay alloys in their bulk form are relatively weak alloys, they have the ability when applied as a thin layer to another, harder bearing alloy to increase the fatigue strength of a bearing embodying that harder and intrinsically stronger bearing alloy. This is effected due to the conformability of the overlay alloy by being able to deform slightly to accommodate slight mis-alignments, especially in new engines during the “running in” phase, and so spread the load more evenly across the bearing surface area.
As noted above, many conventional overlay alloys are based on alloys of lead. Lead is a toxic metal which will eventually be phased out of use by governmental legislation throughout the world. In order to make the lead-based overlay layer less prone to corrosion in hot engine oils about 10 weight % of tin is frequently added or, alternatively, 7 to 10 wt % of indium. Indium, however, is relatively very expensive compared with tin and tends to be used for more expensive, higher performance vehicles. However, when tin is used in the overlay alloy and is deposited upon a harder bearing alloy such as copper-lead, for example, a problem exists in that the tin under engine operating conditions tends to diffuse out of the overlay into the lead of the underlying bearing alloy, as does indium. This is solved by coating the surface of the underlying, harder bearing alloy with a thin diffusion barrier of about 1-3 μm of a metal such as nickel. However, this is not entirely satisfactory as diffusion still occurs and the overlay still becomes depleted in tin due to the formation of non-equilibrium intermetallic compounds such as Ni 3 Sn or Ni 3 Sn 2 which are not good bearing materials in the situation where the shaft journal wears through the overlay to the underlying interface comprising these intermetallic compounds.
With the ever increasing demands placed on bearings by engines having higher specific outputs and operating at higher engine revolutions, there has been a demand for these relatively soft overlay alloys to have improved wear resistance whilst at least maintaining existing levels of fatigue, cavitation resistance and corrosion resistance. This demand has resulted in the development of so-called lead-tin-copper overlay alloys an example of which is Pb-10Sn-2Cu.
Thus, it is an object of the present invention to provide an overlay layer which is not toxic and a further object is to provide an overlay which does not form undesirable compounds at an interface with an underlying, harder bearing material. A yet further object is to provide an overlay having improved performance over known lead-based overlay alloys.
SUMMARY
According to a first aspect of the present invention there is provided a plain bearing having an overlay material layer at a sliding surface of the plain bearing, the plain bearing comprising a layer of a strong backing material, a layer of a first bearing alloy bonded to the strong backing material and a layer of a second bearing alloy comprising said overlay material bonded to said first bearing alloy layer wherein said second bearing material comprises tin having included in the matrix thereof an organic levelling agent.
The tin overlay layer according to the present invention comprises essentially pure tin in that there are no metallic alloying constituents, other than unavoidable impurities, however, the tin is deposited from a bath containing additions of one or more organic materials which have the effect of so-called “levelling” on the electro-deposited tin layer.
Organic materials which have been tested in bearings of the present invention embodying tin overlays include nonylphenolpolyglycolether and pyrocatechol. The content of the organic material in the plating bath has an influence on the degree of levelling achieved in the deposited tin layer, the degree of levelling being reflected in the surface roughness of the tin layer.
At low levels of organic levelling agent, too low for the full benefit of the present invention to be felt, the surface appearance of the bearing surface is one of a generally crystalline appearance having pools of smooth material distributed over the surface. At a content of organic levelling agent where the whole surface is smooth, this is the desirable minimum content.
It is believed that the organic levelling agent is incorporated in the matrix of the deposited tin layer as polymer chains occluded in the matrix structure such as in the form of an organo-metallic tin compound, for example. The polymer chains appear to impart a preferred orientation to the tin atoms during deposition which has been found to give improved slip properties. Improved slip properties have been evidenced by lower coefficients of friction in the tin layer compared with ordinary tin deposits without the levelling additions. The surface of the tin overlay of the bearing of the present invention is very smooth giving a lower degree of friction against a co-operating shaft journal which in turn gives improved compatibility between bearing surface and shaft journal resulting in lower wear rates.
The organic constituent of the tin overlay produces an increased hardness in the range from about 20 to 30 Hv. Pure tin with no organic levelling agent, depending upon its condition, has a hardness of about 8-12 Hv. The hardness of the tin overlay can be changed depending upon the content of the organic levelling agent in the plating bath; the lower the content, the lower the corresponding hardness. The reverse is also true in that as the content of levelling agent increases, so also does the hardness. However, it is possible to have too high a content of organic levelling agent such that the hardness is too high and high internal stresses are produced in the deposit which can lead to cracking of the tin deposit. It is intended that the overlay of the bearing of the present invention operates in a similar manner to conventional overlays in that the overlay layer is sufficiently soft to permit particles of dirt circulating in the lubricating oil to become embedded in the overlay so as to prevent such dirt particles from scoring the shaft journal. Whilst the tin overlay of the present invention is harder than pure tin by a factor of ×2 to ×3 it is still sufficiently soft to provide the required characteristic of dirt embeddability thus, the preferred hardness range is 20 to 30 Hv.
The bearing of the present invention may preferably have an interlayer between the surface of the first bearing material and the tin overlay to act as a diffusion barrier therebetween. The metal layer may be of a thickness lying in the range from about 0.1 to about 3 μm with a thickness of 1 to 2 μm being preferred, however, the actual thickness is of comparatively little importance in terms of bearing performance. The metal may be selected from the non-exhaustive group including nickel, cobalt, copper, silver, iron and alloys of these metals, for example. It has been found that under engine operating conditions the tin overlay reacts with the nickel interlayer over time to form the stable equilibrium intermetallic compound, Ni 3 Sn 4 , due to the presence of effectively an excess of tin. As noted above, prior art lead-10tin overlays tended to form the unstable, non-equilibrium Ni 3 Sn or Ni 3 Sn 2 compounds which are poor bearing materials and have inferior compatibility with a shaft journal and have been blamed in the past for causing seizure when the overlay has worn through to the interlayer. Ni 3 Sn 4 on the other hand is a very good bearing material and thus, the overlay of the present invention in addition to having superior resistance to wear and cavitation erosion is also less prone to seizure when the overlay is nearing the end of its life. Thus, this unforeseen effect of generating a good bearing material at the interface is seen as a significant advantage of the bearing of the present invention.
As with known overlay layers, the thickness of the overlay of the bearing of the present invention may lie in the range from about 10 to 30 μm with 13 to 18 μm being preferred.
The deposition conditions for tin overlays according to the present invention may be varied to produce a range of microstructures. For example, analysis of the tin overlay layer by SEM has revealed no discernible grain size; even at magnifications of ×5000 and ×10000 no grains can be resolved. However, coatings having grain sizes of up to 3 μm may be produced. It is preferred, however, that a smaller grain size is produced as these provide improved bearing properties.
According to a second aspect of the present invention, there is provided a method for the deposition of an overlay layer onto the surface of a plain bearing, the bearing comprising a strong backing material having a layer of a first bearing material thereon, said overlay being deposited upon the surface of said first bearing material, the method comprising the steps of: providing a bearing having a surface on which to deposit said overlay; immersing said bearing in a plating solution having a supply of tin ions and an organic levelling agent in said solution; making said bearing cathodic with respect to an anode in said solution; and depositing an overlay of tin, apart from unavoidable impurities, said tin overlay also having said organic levelling agent included in a matrix thereof.
It is preferred to deposit the tin overlay of the bearing of the present invention by using a so-called “slot jig” wherein the bearing is held with its joint faces against a back face of the slot jig with the bore of the bearing facing the slot, the bearing axis and slot being generally parallel to each other. The plating solution, in which the bearing and slot jig are immersed, is also then sparged through the slot towards the bearing bore.
In this way it has been found that relatively high current densities of 2 to 3 A/dm 2 may be employed compared with less than 1 A/dm 2 where the bearing is merely immersed in the plating solution without sparging thereof. Furthermore, the quality of the deposited tin layer is greatly improved compared with that produced without sparging. The use of high current density permitted by the slot jig and sparging technique also reduces plating time from more than 40 minutes to less than 20 minutes.
A typical plating solution producing a tin/organic material overlay on a bearing according to the present invention may have a composition as follows:
Sn ++ 32-38 g/l SnSO 4 58-68 g/l H 2 SO 4 185-210 g/l Cu <50 mg/l Chloride <20 ppm
Levelling agent additions of nonylphenolpolyglycolether (10-25%) in a methanol carrier (2.5-10%) in the range from 18 to 70 ml/l to the solution specified above have been tested. At the lower end of the range it was found that the degree of levelling and hardness increase was insufficient whilst at the upper end of the range it was found that there was too much inherent stress in the tin deposit and cracking occurred. It was found that concentration in the range from 25 to 55 ml/l gave useful increases in overlay performance with little or acceptable deterioration of the fundamental requirements of an overlay alloy in terms of conformability and dirt embeddability. The content of pyrocatecol was 2.5-10% and amphoteres tensid 2.5% maximum.
It has been found that the leveler content has a substantially directly proportional effect on hardness of the tin deposit. However, a limit of leveler content is reached after which the hardness of the tin deposit remains constant and then actually begins to fall after further increasing the leveler content. Similarly, the leveler content also has a directly proportional effect on surface roughness once the effect of the initial substrate roughness and greatly increased surface roughness of the initial leveler-free tin deposit have been overcome.
BRIEF DESCRIPTION OF THE DRAWINGS
In order that the present invention may be more fully understood, examples will now be described by way of illustration only with reference to the accompanying figures, of which:
FIG. 1 shows a cross section through a part of a schematic bearing according to the present invention showing the constituent layers;
FIG. 2 shows a top view of a schematic arrangement of a plating jig having a bearing being plated with a tin/organic material according to the method of the present invention;
FIG. 3 shows a histogram of mean thickness loss of overlay vs main journal number in an engine test comparing bearings according to the present invention and bearings plated with known Pb/In overlays;
FIG. 4 shows a histogram of weight loss vs main journal number of overlays of bearings according to the present invention and known Pb/In plated bearings in a 3000 hour engine test;
FIG. 5 shows a histogram of volume loss of overlays of bearings according to the present invention and known Pb/In and Pb/Sn/Cu overlays in a hot oil corrosion test;
FIG. 6 shows a histogram of fatigue strength of bearings according to the present invention having a tin/organic material overlay and known Pb/In and Pb/Sn/Cu overlays;
FIG. 7 shows a histogram of volume loss of overlays of bearings according to the present invention, Pb/Sn/Cu and Pb/In overlays;
FIG. 8 shows a graph of leveler content vs hardness; and
FIG. 9 which shows a graph of leveler content vs surface roughness of the deposit on a substrate.
DETAILED DESCRIPTION
Referring now to FIG. 1 which shows a cross section of a small portion of a generalised bearing 10 according to the present invention. The bearing comprises: a strong backing material 12 (only a part of the thickness of which is shown); a layer of a first bearing material 14 bonded to the backing 12 ; an interlayer 16 ; and, an overlay layer 18 of tin which includes an organic levelling agent combined in the matrix thereof. The backing layer 12 may be steel, for example, but may be any other suitable material such as bronze for example if corrosion conditions in the application dictated such. The first bearing material layer 14 may be any that is suitable but will generally be chosen from copper-based alloys or aluminium-based alloys. The interlayer 16 is present to form a diffusion barrier to stop rapid diffusion of the tin from the overlay 18 into the bearing alloy layer 14 in the case of copper-based alloys 14 and to improve the adhesion of the overlay to the bearing alloy in the case of aluminium-based alloys 14 . The interlayer will generally be deposited by electro-deposition where the overlay is so deposited and may comprise a layer of nickel or other suitable material as described hereinabove. In use, the bearing 10 will be subject to temperatures up to about 160° C. At temperatures of 90° C. and above, the tin from the overlay will react with the interlayer material to form the stable intermetallic compound Ni 3 Sn 4 in the case of a nickel interlayer. The rate of formation increases as the temperature rises. The Ni 3 Sn 4 layer grows at the expense of the overlay, however, the Ni 3 Sn 4 layer is a good bearing material per se with good compatibility with the co-operating shaft journal (not shown) and thus, does not present a possible seizure threat. The thickness of the interlayer 16 generally lies in the range from 1 to 3 μm and the thickness of the overlay 18 generally in the range from 13 to 18 μm.
FIG. 2 shows a top plan view of a schematic arrangement 20 of electro-plating apparatus for depositing an overlay 18 on a bearing 10 . The apparatus comprises a jig 22 having two plates 24 , 26 spaced either side of a slot 28 . The bearing 10 is held against the plates 24 , 26 on its joint faces 30 . The jig 22 is immersed in a bath (not shown) of plating solution 32 as is a tin anode 34 of generally cylindrical form. The bearing 10 is made cathodic by a suitable electrical connection (not shown). A sparging tube 36 having holes 38 is situated vertically in the bath in a fixed relationship to the slot 28 . Plating solution is pumped through the tube 36 so as to emerge in jet form, as indicated by the arrows 40 , which are directed towards the bore of the bearing 10 through the slot 28 . Although not apparent from FIG. 2 , the jig 22 is elongate as are the anode 34 and sparging tube 36 and there is generally a stack of a plurality of bearings 10 being plated simultaneously.
In the tests results which follow, the overlay was deposited upon the relevant substrate alloy bearing alloy 14 and interlayer 16 from a plating bath having the following composition:
Sn ++
32-38
g/l
SnSO 4
58-68
g/l
H 2 SO 4
185-210
g/l
Cu
<50
mg/l
Chloride
<20
ppm
Levelling agent additions of nonylphenolpolyglycolether (10-25%) in a methanol carrier (2.5-10%) in the range from 32 to 35 ml/l were added to the above aqueous solution.
The interlayer 16 material was in all cases nickel.
FIG. 3 indicates the results of a 3000 hour test on a Volvo (trade name) diesel truck engine. Main bearings 1 to 4 inclusive were fitted with bearings according to the present invention as described above whilst main bearings 5 to 7 inclusive were fitted with bearings of the same material and construction but having a conventional overlay of Pb-7In. As may be seen from the histogram of FIG. 3 , the mean overlay thickness loss for bearings of the present invention was less than 10% that of the conventional overlay.
FIG. 4 shows the results of the 3000 hour Volvo engine test of FIG. 3 in terms of weight loss. Weight loss of the bearings according to the present invention was significantly less than 100 mg each for the four main bearings on journals 1 to 4 whereas the weight loss of the bearings on journals 5 to 7 was around 1000 mg each.
FIG. 5 is a histogram showing weight loss of overlays in hot oil (white medicinal oil which is chosen for its particularly corrosive nature) after 1000 hours at 120° C., the loss being measured in mm 3 . The bearing material on which the overlays were deposited has a composition CuSn10 which was cast onto steel. The overlays were tin as in the present invention, Pb-7In and Pb-10Sn-2Cu. As may be seen from FIG. 5 , the volume loss of overlays on bearings according to the present invention was about 60% that of Pb-10Sn-2Cu and much less than 10% that of the Pb-7In overlay.
FIG. 6 is a histogram showing the fatigue strength of bearings having the overlays specified The bearings according to the present invention were tested in two forms: one having a thickness of 18 μm at the upper end of the preferred thickness range; and, the second having a thickness of 14 μm at the lower end of the preferred thickness range. The overlay thicknesses of the prior art Pb-10Sn-2Cu and Pb-7In overlays was 15-16 μm. As may be seen from FIG. 6 the fatigue strength of the bearings according to the present invention was significantly greater than the prior art bearings.
Further tests were carried out where the tin overlay having a thickness in the range from 13 to 18 μm was deposited on bearing materials 14 of Cu-30Pb-1.5Sn and Cu-10Sn gave fatigue strengths of 90 to 103 MPa.
FIG. 7 is a histogram showing wear test results showing volume loss of overlay on bearings according to the present invention compared with conventional overlays as described hereinabove. The test conditions were: temperature 120°; load 8 kg; speed 500 rev/min; duration 10 mins; and a constant flow of low oil at 600 ml/min. As may be seen from FIG. 7 the volume loss of overlays according to the present invention is less than 50% of Pb-10Sn-2Cu and less than 40% that of Pb-7In.
Tests were also carried out on the cavitation resistance of overlays on bearings according to the present invention. In these tests, the weight loss of the tin overlay of the inventive bearing was 9 mg whereas the weight loss of a Pb-7In overlay under identical conditions was 37 mg.
FIG. 8 shows the effect of leveler content in the plating bath on the hardness of the tin deposit. It may be seen that the hardness increases linearly with increasing content of leveler which was the same as that in the previously described example.
FIG. 9 shows the effect of leveler content on surface roughness of the tin deposit. At low leveler contents below about 2 ml/l of leveler, the high roughness is a consequence of the substrate surface roughness which was an Ra of o.44 and the roughening effect of the initial, substantially leveler-free tin deposit. Once the effect of the leveler was such that the surface roughness matched that of the substrate then increasing quantities of leveler were directly proportional to the surface roughness.
Thus, relatively low contents of leveler have a strong effect in hardening and smoothing out surface roughness of the tin overlays of the present invention.
Thus, it may be seen that the performance of overlays on bearings according to the present invention is greatly superior to the best conventional overlays deposited by electro-deposition. Where the overlay is deposited upon a lead-free bearing material 14 , the bearing of the present invention provides a completely lead-free bearing which complies with future legislation relating to the elimination of lead from vehicles.
|
A plain bearing and method for making the same are shown and described. The plain bearing includes a layer of a strong backing material to which a first bearing alloy is bonded. A second layer of bearing material overlays the first bearing layer and comprises essentially pure tin without any other metallic alloying constituents and an organic levelling agent in the matrix thereof.
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[0001] This application claims the benefit of Chinese Patent Application No. 201110002095.7, filed with the Chinese Patent Office on Jan. 6, 2011 and entitled “Coverage area compensation and restoration method and apparatus”, which is hereby incorporated by reference in its entirety.
FIELD
[0002] The present invention relates to the field of communications and particularly to a coverage area compensation and restoration method and apparatus.
BACKGROUND
[0003] Along with the dramatic economic and social development, people have ignored or disregarded negative effects due to their excessive pursuing of the satisfactory development and the development pace, and numerous hidden dangers have been concealed for their future development despite their extremely satisfied material desires, so that these problems, e.g., an greenhouse effect, water pollution, etc., will be increasingly prominent over time until human survival is endangered. To some extent, all of these problems may be attributable to people's incomplete understanding of their development that any problem would be readily solved as long as their economic development could be attained, thus ignoring environmental protection. In fact, the problems faced by the human being can be constantly solved only by their scientific development. Thus energy-saving and emission reduction and a low-carbon lifestyle have become hotspots of social interest.
[0004] Those skilled in the art of communications have identified this issue and conceived energy-saving of communication devices. Referring to FIG. 1 , cells A to G of an Evolved Universal Terrestrial Radio Access Network (E-UTRAN) abut each other without overlapping coverage, that is, the E-UTRAN network has single-layer coverage. Particularly the cell A has a coverage compensation function, and the cells B to G have an energy-saving function. During a low-service period (e.g., late at night), the E-UTRAN cells B to G are deactivated for energy-saving, and the cell A acting as a compensation node enlarges its coverage area and provides essential service coverage of this region, thus avoiding a coverage hole arising from deactivation of the energy-saving cells and ensuring continuity of Long Term Evolution (LTE) coverage.
[0005] However there has been absent so far an effective solution to how to control an energy-saving cell to be deactivated and to enlarge a coverage area of a compensation cell.
SUMMARY
[0006] Embodiments of the invention provide a coverage area compensation and restoration method and apparatus so as to perform energy-saving and compensation between the nodes.
[0007] A coverage area compensation method includes the steps of:
[0008] determining from preset energy-saving and compensation strategies whether a trigger condition to initiate an energy-saving and compensation process is satisfied; and
[0009] a first erode performing an energy-saving operation in the energy-saving and compensation process and a second node performing a compensation operation in the energy-saving and compensation process when the trigger condition to initiate the energy-saving and compensation process is satisfied.
[0010] A coverage area restoration method includes the steps of:
[0011] determining from preset energy-saving and compensation restoration strategies whether a trigger condition to initiate a coverage restoration process is satisfied; and
[0012] a first node performing an energy-saving restoration operation in the coverage restoration process find a second node performing a compensation restoration operation in the coverage restoration process when the trigger condition to initiate the coverage restoration process is satisfied.
[0013] A coverage area compensation apparatus includes:
[0014] a strategy module configured to determine from preset energy-saving and compensation strategies whether a trigger condition to initiate an energy-saving and compensation process is satisfied or to receive a trigger for the energy-saving and compensation process from an Operation, Administration and Maintenance, OAM, entity; and
[0015] an enforcement module configured to perform an energy-saving operation in the energy-saving and compensation process or to perform a compensation operation in the energy-saving and compensation process when the energy-saving and compensation process is determined to be initiated,
[0016] wherein the apparatus is an energy-saving node when performing the energy-saving operation in the energy-saving and compensation process; and the apparatus is a compensation node when performing the compensation operation in the energy-saving and compensation process.
[0017] A coverage area restoration apparatus includes:
[0018] a strategy module configured to determine from preset energy-saving and compensation restoration strategies whether a trigger condition to initiate a coverage restoration process is satisfied or to receive a trigger for the coverage restoration process from an Operation, Administration and Maintenance, OAM, entity; and
[0019] an enforcement module configured to perform an energy-saving restoration operation in the coverage restoration process or a compensation restoration operation in the coverage restoration process when an energy-saving and compensation process is determined to be initiated,
[0020] wherein the apparatus is an energy-saving node when performing the energy-saving restoration operation in the energy-saving and compensation restoration process; and the apparatus is a compensation node when performing the compensation restoration operation in the energy-saving and compensation restoration process.
[0021] An Operation, Administration and Maintenance, OAM, apparatus includes:
[0022] a strategy module configured to determine from preset energy-saving and compensation strategies whether a trigger condition to initiate an energy-saving and compensation process is satisfied; and
[0023] a interface module configured to trigger a first node and a second node to perform the energy-saving and compensation process when the energy-saving and compensation process is determined to be initiated,
[0024] wherein the first node is a compensation node, and the second node is an energy-saving node; or the first node is an energy-saving node, and the second node is a compensation node.
[0025] An Operation, Administration and Maintenance, OAM, apparatus includes:
[0026] a strategy module configured to determine from preset energy-saving and compensation restoration strategies whether a trigger condition to initiate a coverage restoration process is satisfied; and
[0027] an interface module configured to trigger a first node and a second node to perform an energy-saving and compensation restoration process when the coverage restoration process is determined to be initiated,
[0028] wherein the first node is a compensation node, and the second node is an energy-saving node; or the first node is an energy-saving node, and the second node is a compensation node.
[0029] A node in an embodiment of the invention sends a compensation request to another related node when an energy-saving or compensation strategy is satisfied so that the node sending the request and the another related node perform an energy-saving or compensation operation to implement energy-saving and compensation between the nodes.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] FIG. 1 is a schematic diagram of adjacent cells in the prior art;
[0031] FIG. 2 is a general flow chart of a coverage area compensation method in an embodiment of the invention;
[0032] FIG. 3 is a flow chart of a method of a compensation node initiating energy-saving and compensation in a forced process in an embodiment of the invention;
[0033] FIG. 4 is a flow chart of a method of a compensation node initiating energy-saving and compensation in a one-negotiation process in an embodiment of the invention;
[0034] FIG. 5 is a flow chart of a method of a compensation node initiating energy-saving and compensation in a two-negotiation process in an embodiment of the invention;
[0035] FIG. 6 is a flow chart of a method of an energy-saving node initiating energy-saving and compensation in a forced process in an embodiment of the invention;
[0036] FIG. 7 is a flow chart of a method of an energy-saving node initiating energy-saving and compensation in a one-negotiation process in an embodiment of the invention;
[0037] FIG. 8 is a flow chart of a method of an energy-saving node initiating energy-saving and compensation in a two-negotiation process in an embodiment of the invention;
[0038] FIG. 9 is a flow chart of a method of an Operation, Administration and Maintenance (OAM) entity initiating energy-saving and compensation in a forced process in an embodiment of the invention;
[0039] FIG. 10 is a flow chart of a method of initiating an energy-saving and compensation process automatically after an OAM entity pre-configures energy-saving and compensation strategies in an embodiment of the invention;
[0040] FIG. 11 is a general flow chart of a coverage area restoration method in an embodiment of the invention;
[0041] FIG. 12 is a flow chart of a method of a compensation node initiating coverage restoration in a forced process in an embodiment of the invention;
[0042] FIG. 13 is a flow chart of a method of a compensation node initiating coverage restoration in a one-negotiation process in an embodiment of the invention;
[0043] FIG. 14 is a flow chart of a method of a compensation node initiating coverage restoration in a two-negotiation process in an embodiment of the invention;
[0044] FIG. 15 is a flow chart of a method of an energy-saving node initiating coverage restoration in a forced process in an embodiment of the invention;
[0045] FIG. 16 is a flow chart of a method of an energy-saving node initiating coverage restoration in a one-negotiation process in an embodiment of the invention;
[0046] FIG. 17 is a flow chart of a method of an energy-saving node initiating coverage restoration in a two-negotiation process in an embodiment of the invention;
[0047] FIG. 18 is a flow chart of a method of an OAM entity initiating coverage restoration in a forced process in an embodiment of the invention;
[0048] FIG. 19 is a flow chart of a method of initiating a coverage restoration process automatically after an OAM entity pre-configures energy-saving and compensation strategies in an embodiment of the invention;
[0049] FIG. 20 is a general structural diagram of a coverage area compensation apparatus in an embodiment of the invention;
[0050] FIG. 21 is a detailed structural diagram of a coverage area compensation apparatus in an embodiment of the invention;
[0051] FIG. 22 is a general structural diagram of a coverage area restoration apparatus in an embodiment of the invention;
[0052] FIG. 23 is a detailed structural diagram of a coverage area restoration apparatus in an embodiment of the invention;
[0053] FIG. 24 is a structural diagram of an OAM entity performing energy-saving and compensation in an embodiment of the invention; and
[0054] FIG. 25 is a structural diagram of an OAM entity performing energy-saving and compensation restoration in an embodiment of the invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0055] A node in an embodiment of the invention sends a compensation request to another related node when an energy-saving or compensation strategy is satisfied so that the node sending the request and the another related node perform an energy-saving or compensation operation to implement energy-saving and compensation between the nodes.
[0056] Referring to FIG. 2 , a general flow of a coverage area compensation method in this embodiment is as follows:
[0057] Step 201 : it is determined from preset energy-saving and compensation strategies whether a trigger condition to initiate an energy-saving and compensation process is satisfied.
[0058] Step 202 : When the trigger condition to initiate the energy-saving and compensation process is satisfied, one of a first node and a second node performs an energy-saving operation in the energy-saving and compensation process and the other node performs a compensation operation in the energy-saving and compensation process; otherwise, the step 201 is repeated.
[0059] Particularly the first node is a compensation node, and the second node is an energy-saving node; or the first node is an energy-saving node, and the second node is a compensation node. And the step 201 can be performed by the compensation node or the energy-saving node or can be performed by a third-party OAM entity. And the compensation node and the energy-saving node can trigger and negotiate about the energy-saving and compensation operations in numerous ways. In this embodiment, the compensation node enforces the compensation strategy among the energy-saving and compensation strategies, and the energy-saving node enforces the energy-saving strategy among the energy-saving and compensation strategies. An implementation process will be introduced below in details in several embodiments.
[0060] Referring to FIG. 3 , a flow of a method of a compensation node initiating energy-saving and compensation in a forced process in this embodiment is as follows:
[0061] Step 301 : A compensation node determines from a preset compensation strategy an energy-saving and compensation process is to be initiated. Numerous preset compensation strategies are possible, for example, a preset point of time is reached, e.g., 11:00 p.m. Other compensation strategies are also possible and will not be enumerated here so as to avoid a repeated description thereof, and any compensation strategy with an energy-saving and compensation process to be initiated can be applicable to this embodiment. Particularly the compensation strategy can be preconfigured by an Operation, Administration and Maintenance (OAM) entity or can be exchanged between cells.
[0062] Step 302 : The compensation node sends a compensation request to an energy-saving node to instruct the energy-saving node to perform deactivation. The compensation request can particularly be a cell compensation indication. The cell compensation indication carries the identifiers of target cells to be deactivated and can further include a minimum period of time after which a target cell is deactivated, that is, the target cell will not be deactivated until the end of this period of time and will be deactivated after a time which is no shorter than this period of time so that the compensation node has sufficient time to cover the target cell so as to reduce or avoid a coverage hole from occurring. The compensation node can send a cell compensation indication to all the adjacent energy-saving nodes concurrently, and then the cell compensation indication carries the identifiers of cells served by all the adjacent energy-saving nodes. Alternatively the compensation node sends cell compensation indications separately to respective adjacent energy-saving nodes, and then the cell compensation indication for each energy-saving node carries the identifiers of cells served by the energy-saving node.
[0063] Step 303 : The compensation node enlarges a coverage area. For example, a particular operation is to boost transmission power, to adjust an inclination angle of an antenna, etc.
[0064] Step 304 : For the enlarged cell, the compensation node interacts with new adjacent cells and collects RLF and other related information of the new adjacent cells so as to further adjust transmission power and optimize the coverage area.
[0065] Step 305 : The energy-saving node switches an intra-cell user to the cell served by the compensation node upon reception of the compensation request. If there is an accessing user served by the energy-saving node, then this step will be performed; otherwise, this step will be skipped.
[0066] Step 306 : The energy-saving node enters an energy-saving state and performs a deactivation operation. Numerous deactivation operations are possible, e.g., to deactivate transmission. Preferably the energy-saving node reserves only a sounding function so as to receive an energy-saving state quit instruction.
[0067] Particularly a process of the steps 303 and 304 and a process of the steps 305 and 306 are two separate processes and can be performed in synchronization.
[0068] In this embodiment, if there is an X2 interface between the compensation node and the energy-saving node, then the compensation node can send the cell compensation indication to the energy-saving node via the X2 interface, and an example of the structure of the cell compensation indication is as depicted in Table 1. If there is no X2 interface between the compensation node and the energy-saving node or there is an inter-RAT scenario between the compensation node and the energy-saving node, then the cell compensation indication will be forwarded by a device in a Core Network (CN) to the energy-saving node, and at this time an example of the structure of the cell compensation indication is as depicted in Table 2, and simply the device in the core network can transparently transmit the cell compensation indication directly.
[0000]
TABLE 1
Information Element
(IE)/Group Name
Value range
Description
Message Type
Served Cells To
1 to maxCellineNB, i.e., the
Indicate target cells requested to
Compensate
maximum identifier of cells
be deactivated
served by a NodeB
>Evolved Cell Global
Indicate the identifier of a cell
Identifier (ECGI)
Time to wait
Indicate a minimum period of
time after which a target cell is
allowed to be deactivated
[0000]
TABLE 2
IE/Group
IE type and
Semantics
Name
Presence
Range
reference
description
CHOICE
Must (M)
Energy-saving
Application)
>Served Cells
Indicate target cells
To Compensate
requested to be
deactivated
>>ECGI
M
>Time to wait
Optional
Indicate a minimum
(O)
period of time after
whic ha target cell is
allowed to be
deactivated
[0069] Referring to FIG. 4 , a flow of a method of a compensation node initiating energy-saving and compensation in a one-negotiation process in this embodiment is as follows:
[0070] Step 401 : A compensation node determines from a preset compensation strategy an energy-saving and compensation process is to be initiated.
[0071] Step 402 : The compensation node sends a compensation request to an energy-saving node to instruct the energy-saving node to perform deactivation. The compensation request can particularly be an energy-saving request or a cell compensation request. The energy-saving request or the cell compensation request carries the identifiers of target cells to be deactivated and can further include a minimum period of time after which a target cell is deactivated and enlarged coverage related information. A variety of enlarged coverage related information is possible, for example, a maximum coverage radius, maximum transmission power, current load information, remaining available load information, etc., of the compensation node. Particularly an energy-saving request in the prior art is applicable to an overlapping coverage scenario and only instructs a target cell to be deactivated, but a compensation node will not compensate. In this embodiment, the energy-saving request is applied to a single-layer coverage scenario and instructs a target cell to be deactivated, but also the compensation node compensates coverage of the target cell.
[0072] The compensation node can send a cell compensation request to all the adjacent energy-saving nodes concurrently, and then the cell compensation request carries the identifiers of cells served by all the adjacent energy-saving nodes. Alternatively the compensation node sends cell compensation requests separately to respective adjacent energy-saving nodes, and then the cell compensation request for each energy-saving node carries the identifiers of cells served by the energy-saving node.
[0073] Step 403 . The energy-saving node determines whether to agree on energy-saving from a local energy-saving strategy and the received enlarged coverage related information, and if so, then the flow proceeds to the step 404 ; otherwise, the flow proceeds to the step 407 . Particularly the energy-saving strategy can be preconfigured by an OAM entity or can be exchanged between cells.
[0074] Step 404 : The energy-saving node returns an acceptance message indicating acceptance of an energy-saving operation. The acceptance message can particularly be a cell compensation response. The cell compensation response includes the identifier of a cell accepting energy-saving, that is, any cell without its corresponding cell identifier being carried will not accept an energy-saving operation, so a failure message as returned below may not carry a cell identifier.
[0075] Step 405 : The energy-saving node switches an intra-cell user to the cell served by the compensation node upon agreement on energy-saving. If there is an accessing user served by the energy-saving node, then this step will be performed; otherwise, this step will be skipped.
[0076] Step 406 : The energy-saving node enters an energy-saving state and performs a deactivation operation. Numerous deactivation operations are possible, e.g., to deactivate transmission. Preferably the energy-saving node reserves only a sounding function so as to receive an energy-saving state quit instruction.
[0077] Step 407 : The energy-saving node returns a failure message indicating rejection of an energy-saving operation. The failure message can particularly be a cell compensation failure. The cell compensation failure may carry information indicating a reason for rejection of an energy-saving operation.
[0078] Step 408 : The compensation node enlarges a coverage area upon reception of the acceptance message.
[0079] Step 409 : For the enlarged cell, the compensation node interacts with new adjacent cells and collects RLF and other related information of the new adjacent cells so as to further adjust transmission power and optimize the coverage area.
[0080] Step 410 : The compensation node operates as it is upon reception of the failure message.
[0081] In this embodiment, if there is an X2 interface between the compensation node and the energy-saving node, then the messages exchanged between the compensation node and the energy-saving node can be transmitted directly via the X2 interface, and at this time an example of the structure of the cell compensation request is as depicted in Table 3, an example of the structure of the cell compensation response is as depicted in Table 4, and an example of the structure of the cell compensation failure is as depicted in Table 5. If there is no X2 interface between the compensation node and the energy-saving node or there is an inter-RAT scenario between the compensation node and the energy-saving node, then the messages between the compensation node and the energy-saving node will be forwarded transparently by a device in a Core Network (CN), and at this time an example of the structure of the cell compensation request is as depicted in Table 6, an example of the structure of the cell compensation response is as depicted in Table 7, and an example of the structure of the cell compensation failure is as depicted in Table 8.
[0000]
TABLE 3
IE/Group Name
Value range
Description
Message Type
Served Cells To
1 to
Indicate target cells requested to be
Compensate
maxCellineNB
deactivated
>ECGI
Indicate the identifier of a cell
Served
Indicate a service coverage area to
Coverage Area
be compensated
Load Information
Indicate current load information or
available capacity information
Time to wait
Indicate a minimum period of time
after which a target cell is allowed
to be deactivated
[0000]
TABLE 4
IE/Group Name
Value range
Description
Message Type
Compensated Cell List
1 to maxCellineNB
List of cells receiving an
instruction and successfully
responding with a
compensation operation
>ECGI
Criticality Diagnostics
[0000]
TABLE 5
IE/Group Name
Message Type
Value range
Description
Cause
Reason for rejection
Criticality Diagnostics
[0000]
TABLE 6
IE type and
Semantics
IE/Group Name
Presence
Range
reference
description
CHOICE
M
Energy-saving
Application
>Served Cells to
Compensate
>>ECGI
M
>Served Coverage
O
Area
>Load Information
O
>Time to wait
O
[0000]
TABLE 7
IE type and
Semantics
IE/Group Name
Presence
Range
reference
description
CHOICE Energy-
M
saving Application
>Served Cells To
Compensate
>>ECGI
M
[0000]
TABLE 8
IE type and
Semantics
IE/Group Name
Presence
Range
reference
description
CHOICE Energy-
M
saving Application
>Cause
O
[0082] Referring to FIG. 5 , a flow of a method of a compensation node initiating energy-saving and compensation in a two-negotiation process in this embodiment is as follows:
[0083] Step 501 : A compensation node determines from a preset compensation strategy an energy-saving and compensation process is to be initiated.
[0084] Step 502 : The compensation node sends a compensation request to an energy-saving node to instruct the energy-saving node to perform deactivation. The compensation request can particularly be a cell compensation request.
[0085] Step 503 . The energy-saving node determines whether to agree on energy-saving from a local energy-saving strategy and received enlarged coverage related information, and if so, then the flow proceeds to the step 504 ; otherwise, the flow proceeds to the step 505 .
[0086] Step 504 : The energy-saving node returns an acceptance message indicating acceptance of an energy-saving operation. The acceptance message can particularly be a cell compensation response. The cell compensation response includes the identifiers of cells accepting energy-saving, that is, any cell without its corresponding cell identifier being carried will not accept an energy-saving operation, so a failure message as returned below may not carry a cell identifier. The cell compensation response can further include the number of users and the amount of data to be switched, etc.
[0087] Step 505 : The energy-saving node returns a failure message indicating rejection of an energy-saving operation. The failure message can particularly be a cell compensation failure. The cell compensation failure may carry information indicating a reason for rejection of an energy-saving operation.
[0088] Step 506 : The compensation node determines from a preset adjustment strategy a cell for which energy-saving is finally required upon reception of the acceptance message. Numerous adjusting strategies are possible, for example, the number of users and the amount of data acceptable to switch together with cells where this part of users reside are determined from the size of a local available load capacity and the number of users and the amount of data received to be switched. Particularly the adjustment strategy can be configured by an OAM entity or can be exchanged between cells.
[0089] Step 507 : The compensation node sends a cell deactivation request to the energy-saving node. The cell deactivation request carries the cell identifier of the cell for which energy-saving is finally required.
[0090] Step 508 : The compensation node enlarges a coverage area.
[0091] Step 509 : For the enlarged cell, the compensation node interacts with new adjacent cells and collects RLF and other related information of the new adjacent cells so as to further adjust transmission power and optimize the coverage area.
[0092] Step 510 : The compensation node operates as it is upon reception of the failure message.
[0093] Step 511 : The energy-saving node switches an intra-cell user to the cell served by the compensation node upon reception of the cell deactivation request. If there is an accessing user served by the energy-saving node, then this step will be performed; otherwise, this step will be skipped.
[0094] Step 512 : The energy-saving node enters an energy-saving state and performs a deactivation operation. Numerous deactivation operations are possible, e.g., to deactivate transmission. Preferably the energy-saving node reserves only a sounding function so as to receive an energy-saving state quit instruction.
[0095] To perform an energy-saving and compensation operation, the operation can alternatively be initiated by the energy-saving node, and for a particular process, reference can be made to the following embodiments.
[0096] Referring to FIG. 6 , a flow of a method of an energy-saving node initiating energy-saving and compensation in a forced process in this embodiment is as follows:
[0097] Step 601 : An energy-saving node determines from a preset energy-saving strategy an energy-saving and compensation process is to be initiated. Numerous preset energy-saving strategies are possible, for example, a preset point of time is reached, e.g., 11:00 p.m. Other energy-saving strategies are also possible and will not be enumerated here so as to avoid a repeated description, and any energy-saving strategy with an energy-saving and compensation process to be initiated can be applicable to this embodiment. Particularly the energy-saving strategy can be preconfigured by an OAM entity or can be exchanged between cells.
[0098] Step 602 : The energy-saving node sends a compensation request to a compensation node to request the compensation node for provision of coverage compensation. The compensation request can particularly be a cell compensation indication. The cell compensation indication carries the identifiers of target cells to be deactivated and can further include a minimum period of time after which a target cell is deactivated. Particularly the energy-saving node can send the compensation request to the compensation node directly via an X2 interface; or can have the compensation request transparently transmitted to the compensation node over a core network.
[0099] Step 603 : The energy-saving node switches an intra-cell user to a cell served by the compensation node. If there is an accessing user served by the energy-saving node, then this step will be performed; otherwise, this step will be skipped.
[0100] Step 604 : The energy-saving node enters an energy-saving state and performs a deactivation operation. Numerous deactivation operations are possible, e.g., to deactivate transmission. Preferably the energy-saving node reserves only a sounding function so as to receive an energy-saving state quit instruction. And in order to reduce or avoid a coverage hole from occurring, the energy-saving node waits for a period of time after sending the compensation request and performs a deactivation operation when the length of the wait period of time reaches the minimum period of time after which a target cell is deactivated.
[0101] Step 605 : The compensation node enlarges a coverage area upon reception of the compensation request. For example, a particular operation is to boost transmission power, to adjust an inclination angle of an antenna, etc.
[0102] Step 606 : For the enlarged cell, the compensation node interacts with new adjacent cells and collects RLF and other related information of the new adjacent cells so as to further adjust transmission power and optimize the coverage area.
[0103] Referring to FIG. 7 , a flow of a method of an energy-saving node initiating energy-saving and compensation in a one-negotiation process in this embodiment is as follows:
[0104] Step 701 : An energy-saving node determines from a preset energy-saving strategy an energy-saving and compensation process is to be initiated.
[0105] Step 702 : The energy-saving node sends a compensation request to a compensation node to request the compensation node for provision of coverage compensation. The compensation request can particularly be a cell compensation request. The cell compensation indication carries the identifiers of target cells to be deactivated and can further include a minimum period of time after which a target cell is deactivated, load related information of the target cells, etc. A variety of load related information of the target cells is possible, e.g., the number of users and the amount of data per target cell, etc.
[0106] Step 703 : The compensation node determines whether to agree to provide coverage compensation from a local compensation strategy and the received load related information of the target cells, and if so, then the flow proceeds to the step 704 ; otherwise, the flow proceeds to the step 709 . Particularly the compensation strategy can be preconfigured by an OAM entity or can be exchanged between cells. Numerous compensation strategies are possible, for example, if a local available remaining capacity satisfies at least a demand of a part of the target cells for the amount of data, then the compensation node agrees to provide this part of the target cells with coverage compensation. Other compensation strategies are also possible and will not be enumerated here so as to avoid a repeated description thereof.
[0107] Step 704 : The compensation node returns an acceptance message indicating acceptance of a coverage compensation operation. The acceptance message can particularly be a cell compensation response. The cell compensation response includes the identifier of a cell accepted to be compensated, that is, any cell without its corresponding cell identifier being carried will not be provided with a compensation operation, so a failure message as returned below may not carry a cell identifier.
[0108] Step 705 : The compensation node enlarges a coverage area after returning the acceptance message.
[0109] Step 706 : For the enlarged cell, the compensation node interacts with new adjacent cells and collects RLF and other related information of the new adjacent cells so as to further adjust transmission power and optimize the coverage area.
[0110] Step 707 : The energy-saving node switches an intra-cell user to the cell served by the compensation node upon reception of the acceptance message. If there is an accessing user served by the energy-saving node, then this step will be performed; otherwise, this step will be skipped.
[0111] Step 708 : The energy-saving node enters an energy-saving state and performs a deactivation operation. Numerous deactivation operations are possible, e.g., to deactivate transmission. Preferably the energy-saving node reserves only a sounding function on as to receive an energy-saving state quit instruction. And in order to reduce or avoid a coverage hole from occurring, the energy-saving node waits for a period of time after receiving the acceptance message and performs a deactivation operation when the length of the wait period of time reaches the minimum period of time after which a target cell is deactivated.
[0112] Step 709 : The compensation node returns a failure message indicating rejection of a coverage compensation operation. The failure message can particularly be a cell compensation failure. The cell compensation failure may carry information indicating a reason for rejection of a coverage compensation operation.
[0113] Step 710 : The energy-saving operates as it is upon reception of the failure message.
[0114] Referring to a flow of a method of an energy-saving node initiating energy-saving and compensation in a two-negotiation process in this embodiment is as follows:
[0115] Step 801 : An energy-saving node determines from a preset energy-saving strategy an energy-saving and compensation process is to be initiated.
[0116] Step 802 : The energy-saving node sends a compensation request to a compensation node to request the compensation node for provision of coverage compensation. The compensation request can particularly be a cell compensation request.
[0117] Step 803 . The compensation node determines whether to agree to provide coverage compensation from a local compensation strategy and received load related information of target cells, and if so, then the flow proceeds to the step 804 ; otherwise, the flow proceeds to the step 805 .
[0118] Step 804 : The compensation mode returns an acceptance message indicating acceptance of a coverage compensation operation. The acceptance message can particularly be a cell compensation response. The cell compensation response includes the identifiers of cells accepted to be compensated, that is, any cell without its corresponding cell identifier being carried will not be provided with a compensation operation, so a failure message as returned below may not carry a cell identifier. The cell compensation response can further include enlarged coverage related information, etc.
[0119] Step 805 : The compensation node returns a failure message indicating rejection of a coverage compensation operation. The failure message can particularly be a cell compensation failure. The cell compensation failure may carry information indicating a reason thr rejection of a coverage compensation operation.
[0120] Step 806 : The energy-saving node determines a cell for which energy-saving is finally required from a preset adjustment strategy upon reception of the acceptance message. Numerous adjusting strategies are possible, for example, the number of users and the amount of data acceptable to switch together with cells where this part of users reside are determined from the size of a received available load capacity and the number of local users and the amount of data to be switched. Particularly the adjustment strategy can be configured by an OAM entity or can be exchanged between cells.
[0121] Step 807 : The energy-saving node sends a cell deactivation request to the compensation node. The cell deactivation request carries the cell identifier of the cell for which energy-saving is finally required.
[0122] Step 808 : The energy-saving node switches an intra-cell user to the cell served by the compensation node after sending the cell deactivation request. If there is an accessing user served by the energy-saving node, then this step will be performed; otherwise, this step will be skipped.
[0123] Step 809 : The energy-saving node enters an energy-saving state and performs a deactivation operation, particularly to deactivate the cell for which energy-saving is finally required. Numerous deactivation operations are possible, e.g., to deactivate transmission. Preferably the energy-saving node reserves only a sounding function so as to receive an energy-saving state quit instruction. And the energy-saving node waits for a period of time after sending the cell deactivation request and performs a deactivation operation when the length of the wait period of time reaches the minimum period of time after which a target cell is deactivated.
[0124] Step 810 : The compensation node sends a compensation request to another non-requesting energy-saving node upon reception of the cell deactivation request to instruct the other energy-saving node to deactivate a cell. The compensation request can be a cell compensation indication or a cell compensation request. For operations of the other energy-saving node upon reception of the compensation request, reference can be made to the flows illustrated in FIG. 3 to FIG. 5 , i.e., the flow charts of the compensation processes initiated by the compensation node. In this step, primarily in view of that the compensation node may have omni-directional coverage, when some cell or cells are provided with coverage compensation, its enlarged coverage area may cover a non-requesting cell or cells and an energy-saving operation can also be performed on this part of cells to save energy. Of course the second negotiation in this embodiment includes negotiation between the compensation node and the other energy-saving node.
[0125] Step 811 : The compensation node enlarges a coverage area.
[0126] Step 812 : For the enlarged cell, the compensation node interacts with new adjacent cells and collects RLF and other related information of the new adjacent cells so as to further adjust transmission power and optimize the coverage area.
[0127] Step 813 : The energy-saving node operates as it is upon reception of the failure message.
[0128] To perform an energy-saving and compensation operation, a device initiating the energy-saving and compensation operation will not be limited to a compensation node and an energy-saving node, but the operation can also be initiated by a third-party device, e.g., an OAM entity, and for a particular process, reference can be made to the following embodiments.
[0129] Referring to FIG. 9 , a method of an OAM entity initiating energy-saving and compensation in a forced process in this embodiment is as follows:
[0130] Step 901 : An OAM entity collects coverage information, load information, etc., of a compensation node and an energy-saving node. This is only exemplary and the OAM entity can collect any energy-saving and compensation related information. This step can be performed periodically or at fixed timings or under some trigger condition.
[0131] Step 902 : The OAM determines from preset energy-saving and compensation strategies an energy-saving and compensation process is to be initiated. The preset energy-saving and compensation strategies can include the compensation strategy of the compensation node in FIG. 3 to FIG. 5 and/or the energy-saving strategy of the energy-saving node in FIG. 6 to FIG. 8 .
[0132] Step 903 : The OAM triggers dynamically the compensation node to activate a compensation state and the energy-saving node to activate an energy-saving state. The OAM can trigger the compensation state and the energy-saving state particularly by sending a compensation request to the compensation node and the energy-saving node. The compensation request can particularly be a cell compensation indication or another configuration message.
[0133] Step 904 : The energy-saving node switches an intra-cell user to a cell served by the compensation node after being triggered. If there is an accessing user served by the energy-saving node, then this step will be performed; otherwise, this step will be skipped.
[0134] Step 905 : The energy-saving node enters the energy-saving state and performs a deactivation operation. Numerous deactivation operations are possible, e.g., to deactivate transmission. Preferably the energy-saving node reserves only a sounding function so as to receive an energy-saving state quit instruction. And in order to reduce or avoid a coverage hole from occurring, the energy-saving node waits for a period of time after being triggered and performs a deactivation operation when the length of the wait period of time reaches a preset minimum period of time after which a target cell is deactivated.
[0135] Step 906 : The compensation node enlarges a coverage area after being triggered. For example, a particular operation is to boost transmission power, to adjust an inclination angle of an antenna, etc.
[0136] Step 907 : For the enlarged cell, the compensation node interacts with new adjacent cells and collects RLF and other related information of the new adjacent cells so as to further adjust transmission power and optimize the coverage area.
[0137] Particularly the steps 904 and 905 can be performed in synchronization with the steps 906 and 907 .
[0138] Referring to FIG. 10 , a flow of a method of initiating an energy-saving and compensation process automatically after an OAM entity pre-configures energy-saving and compensation strategies is as follows:
[0139] Step 1001 : An OAM entity configures a temporal strategy to a compensation node and an energy-saving node. The temporal strategy can be timings or can be periodical. For example, in a timing temporal strategy, the compensation node quits/enters a compensation state again three hours after entering/quitting the compensation state, and also the related energy-saving node is activated/deactivated three hours after being deactivated/activated. For example, in a periodical temporal strategy; the compensation node enters/quits a compensation state for a period of time of 0:00 to 7:00, and also a period of time for which the related energy-saving node enters/quits an energy-saving state can be set the same as 0:00 to 7:00. In this embodiment, the temporal strategy can be regarded as an energy-saving or compensation strategy or a part thereof.
[0140] After the temporal strategy is configured once, the following steps can be performed repeatedly.
[0141] Step 1002 : The energy-saving node switches an intra-cell user to a cell served by the compensation node when the temporal strategy is satisfied. If there is an accessing user served by the energy-saving node, then this step will be performed; otherwise, this step will be skipped.
[0142] Step 1003 : The energy-saving node enters an energy-saving state and performs a deactivation operation. Numerous deactivation operations are possible, e.g., to deactivate transmission. Preferably the energy-saving node reserves only a sounding function so as to receive an energy-saving state quit instruction. And in order to reduce or avoid a coverage hole from occurring, the energy-saving node waits for a period of time after the temporal strategy is satisfied and performs a deactivation operation when the length of the wait period of time reaches a preset minimum period of time after which a target cell is deactivated.
[0143] Step 1004 : The compensation node enlarges a coverage area after the temporal strategy is satisfied. For example, a particular operation is to boost transmission power, to adjust an inclination angle of an antenna, etc.
[0144] Step 1005 : For the enlarged cell, the compensation node interacts with new adjacent cells and collects RLF and other related information of the new adjacent cells so as to further adjust transmission power and optimize the coverage area.
[0145] The foregoing embodiment performs energy-saving and compensation of the cell or the node to thereby save energy and reduce radiation. However the compensation node may fail to satisfy a demand when there is an increase in the number of users or the amount of data, and at this time the energy-saving node will be activated so as to provide a better communication service. A coverage restoration process will be introduced below.
[0146] Referring to FIG. 11 , a general flow of a coverage area restoration method in this embodiment is as follows:
[0147] Step 1101 : It is determined from preset energy-saving and compensation restoration strategies whether a trigger condition to initiate a coverage restoration process is satisfied.
[0148] Step 1102 : If the trigger condition to initiate the coverage restoration process is satisfied, one of a first node and a second node performs an energy-saving restoration operation in the coverage restoration process and the other node performs a compensation restoration operation in the coverage restoration process; otherwise, the step 1101 is repeated.
[0149] Particularly the first node is a compensation node, and the second node is an energy-saving node; or the first node is an energy-saving node, and the second node is a compensation node. Similarly to the coverage area compensation process, the step 1101 can be performed by the compensation node or the energy-saving node or can be performed by a third-party OAM entity. And the compensation node and the energy-saving node can trigger and negotiate about the coverage restoration operations in numerous ways. In this embodiment, the compensation node enforces the compensation restoration strategy among the energy-saving and compensation restoration strategies, and the energy-saving node enforces the energy-saving restoration strategy among the energy-saving and compensation restoration strategies. An implementation process will be introduced below in details in several embodiments.
[0150] Referring to a flow of a method of a compensation node initiating coverage restoration in a forced process in this embodiment is as follows:
[0151] Step 1201 : A compensation node determines from a preset compensation restoration strategy a coverage restoration process is to be initiated. Numerous preset compensation restoration strategies are possible, for example, a preset point of time is reached, e.g., 7 a.m. Other compensation restoration strategies are also possible and will not be enumerated here so as to avoid a repeated description thereof, and any compensation restoration strategy with a coverage restoration process to be initiated can be applicable to this embodiment. Particularly the compensation restoration strategy can be preconfigured by an OAM entity or can be exchanged between cells.
[0152] Step 1202 : The compensation node sends a de-compensation request to an energy-saving node to instruct the energy-saving node to perform activation. The de-compensation request can particularly be a cell de-compensation indication. The cell de-compensation indication carries the identifiers of target cells requested to be activated and can further include a maximum period of tune within which a target cell is activated, that is, the target cell will be activated within this period of time rather than alter this period of time so that when the compensation node narrows a coverage area, the energy-saving node covers the target cell so as to reduce or avoid a coverage hole from occurring. The compensation node can send a cell de-compensation indication to all the adjacent energy-saving nodes concurrently, and then the cell de-compensation indication carries the identifiers of cells served by all the adjacent energy-saving nodes. Alternatively the compensation node sends cell de-compensation indications separately to respective adjacent energy-saving nodes, and then the cell compensation indication for each energy-saving node carries the identifiers of cells served by the energy-saving node.
[0153] Step 1203 : The compensation node switches a user to an activated energy-saving cell. If there is a user, served by the compensation node, to be switched, then this step will be performed; otherwise, this step 11 be skipped. For whether to switch a user, reference can be made to the specification regarding a handover decision in the communication protocol.
[0154] Step 1204 : The compensation node quits a compensation state and narrows a coverage area. For example, a particular operation is to lower transmission power, to adjust an inclination angle of an antenna, etc. The compensation node can switch the user progressively and narrow the coverage area progressively.
[0155] Step 1205 : For the narrowed cell, the compensation node interacts with new adjacent cells and collects RLF and other related information of the new adjacent cells so as to further adjust transmission power and optimize the coverage area.
[0156] Step 1206 : The energy-saving node performs an activation operation and activates all the functions of the cell, served by the node, to be activated upon reception of the de-compensation request.
[0157] Step 1207 : The energy-saving node admits the switched-in user.
[0158] In this embodiment, if there is an X2 interface between the compensation ode and the energy-saving node, then the compensation node can send the cell de-compensation indication to the energy-saving node via the X2 interface, and an example of the structure of the cell de-compensation indication is as depicted in Table 9. If there is no X2 interface between the compensation node and the energy-saving node or there is an inter-RAT scenario between the compensation node and the energy-saving node, then the cell de-compensation indication will be forwarded by a device in a Core Network (CN) to the energy-saving node, and at this time an example of the structure of the cell de-compensation indication is as depicted in Table 10, and simply the device in the core network can transparently transmit the cell de-compensation indication directly.
[0000]
TABLE 9
IE/Group Name
Value range
Description
Message Type
Served Cells To
1 to maxCellineNB,
Indicate target cells requested
Decompensate
i.e., the maximum
to be activated
identifier of cells
served by a NodeB
>Evolved Cell
Indicate the identifier of a cell
Global Identifier
(ECGI)
Time to wait
Indicate a maximum period of
time within which a target cell
is allowed to be activated
[0000]
TABLE 10
IE type and
Semantics
IE/Group Name
Presence
Range
reference
description
CHOICE Energy-
Must (M)
saving
Application
>Served Cells To
Indicate target
Decompensate
cells requested to
be activated
>>ECGI
M
>Time to wait
Optional
(O)
[0159] Referring to FIG. 13 , a flow of a method of a compensation node initiating coverage restoration in a one-negotiation process in this embodiment is as follows:
[0160] Step 1301 : A compensation node determines from a preset compensation restoration strategy a coverage restoration process is to be initiated.
[0161] Step 1302 : The compensation node sends a de-compensation request to an energy-saving node to instruct the energy-saving node to perform activation. The de-compensation request can particularly be a cell de-compensation request. The cell de-compensation request carries the identifiers of target cells requested to be activated and can further include a maximum period of time within which a target cell is activated and narrowed coverage related information. A variety of narrowed coverage related information is possible, for example, a narrowed coverage radius, lowered transmission power, current load information, to-be-transferred load information, etc., of the compensation node.
[0162] The compensation node can send a cell de-compensation request to all the adjacent energy-saving nodes concurrently, and then the cell compensation request carries the identifiers of cells served by all the adjacent energy-saving nodes. Alternatively the compensation node sends cell de-compensation requests separately to respective adjacent energy-saving nodes, and then the cell de-compensation request for each energy-saving node carries the identifiers of cells served by the energy-saving node.
[0163] Step 1303 . The energy-saving node determines whether to agree on restoration from a local de-energy-saving strategy and the received narrowed coverage related information, and if so, then the flow proceeds to the step 1304 ; otherwise, the flow proceeds to the step 1310 . Particularly the de-energy-saving strategy can be preconfigured by an OAM entity or can be exchanged between cells. Numerous de-energy-saving strategies are possible, for example, the energy-saving node agrees on restoration upon reception of a cell de-compensation request, agrees on restoration when a preconfigured point of time is satisfied, etc.
[0164] Step 1304 : The energy-saving node returns an acceptance message indicating acceptance of restoration. The acceptance message can particularly be a cell de-compensation response. The cell de-compensation response includes the identifier of a cell accepting activation, that is, any cell without its corresponding cell identifier being carried will not accept a restoration operation, so a failure message as returned below may not carry a cell identifier.
[0165] Step 1305 : The energy-saving node quits an energy-saving state, performs an activation operation and restores a service of the cell accepting activation upon agreement on restoration.
[0166] Step 1306 : The compensation node switches a user to the activated energy-saving cell upon reception of the acceptance message. If there is a user, served by the compensation node, to be switched, then this step will be performed; otherwise, this step will be skipped. For whether to switch a user, reference can be made to the specification regarding a handover decision in the communication protocol.
[0167] Step 1307 : The compensation node quits a compensation state and narrows a coverage area. For example, a particular operation is to lower transmission power, to adjust an inclination angle of an antenna, etc.
[0168] Step 1308 : For the narrowed cell, the compensation node interacts with new adjacent cells and collects RLF and other related information of the new adjacent cells so as to further adjust transmission power and optimize the coverage area.
[0169] Step 1309 : The energy-saving node admits the switched-in user.
[0170] Step 1310 : The energy-saving node returns a failure message indicating rejection of a restoration operation. The failure message can particularly be a cell de-compensation failure. The cell de-compensation failure may carry information indicating a reason for rejection of a restoration operation.
[0171] Step 1311 : The compensation node operates as it is upon reception of the failure message.
[0172] In this embodiment, if there is an X2 interface between the compensation node and the energy-saving node, then the messages exchanged between the compensation node and the energy-saving node can be transmitted directly via the X2 interface, and at this time an example of the structure of the cell de-compensation request is as depicted in Table 11, an example of the structure of the cell de-compensation response is as depicted in Table 12, and an example of the structure of the cell de-compensation failure is as depicted in Table 13. If there is no X2 interface between the compensation node and the energy-saving node or there is an inter-RAT scenario between the compensation node and the energy-saving node, then the messages between the compensation node and the energy-saving node will be forwarded transparently by a device in a Core Network (CN), and at this time an example of the structure of the cell de-compensation request is as depicted in Table 14, an example of the structure of the cell de-compensation response is as depicted in Table 15, and an example of the structure of the cell de-compensation failure is as depicted in Table 16.
[0000]
TABLE 11
IE/Group Name
Value range
Description
Message Type
Served Cells To
1 to
Indicate target cells requested to be
Decompensate
maxCellineNB
activated
>ECGI
Indicate the identifier of a cell
Served
Indicate a service coverage area to
Coverage Area
be compensated
Load Information
Indicate current load information or
to-be-transferred load information
Time to wait
Indicate a maximum period of time
within which a target cell is allowed
to be activated
[0000]
TABLE 12
IE/Group
Name
Value range
Description
Message Type
Decompensated
1 to maxCellineNB
List of cells receiving an
Cell List
instruction and successfully
responding with a de-compensation
operation
>ECGI
Criticality
Diagnostics)
[0000]
TABLE 13
IE/Group Name
Message Type
Value range
Description
Cause
Reason for rejection
Criticality Diagnostics
[0000]
TABLE 14
IE/Group
IE type and
Semantics
Name
Presence
Range
reference
description
CHOICE
M
Energy saving
Application
>Served Cells
Indicate target cells
To
requested to be
Decompensate
activated
>>ECGI
M
>Served
O
Indicate a service
Coverage Area
coverage area to be
compensated
>Load
O
Indicate current
Information
load information or
to-be-transferred
load information
>Time to wait
O
Indicate a maximum
period of time
within which a
target cell is allowed
to be activated
[0000]
TABLE 15
IE/Group
IE type and
Semantics
Name
Presence
Range
reference
description
CHOICE
M
Energy saving
Application
>Served Cells
Indicate target cells
To
accepting activation
Decompensate
>>ECGI
M
[0000]
TABLE 16
IE type
Semantics
IE/Group Name
Presence
Range
and reference
description
CHOICE Energy
M
saving Application
>Cause
O
[0173] Referring to FIG. 14 , a flow of a method of a compensation node initiating coverage restoration in a two-negotiation process in this embodiment is as follows:
[0174] Step 1401 : A compensation node determines from a preset compensation restoration strategy a coverage restoration process is to be initiated.
[0175] Step 1402 : The compensation node sends a de-compensation request to an energy-saving node to instruct the energy-saving node to perform activation. The de-compensation request can particularly be a cell de-compensation request.
[0176] Step 1403 . The energy-saving node determines whether to agree on restoration from a local de-energy-saving strategy and received narrowed coverage related information, and if so, then the flow proceeds to the step 1404 ; otherwise, the flow proceeds to the step 1405 .
[0177] Step 1404 : The energy-saving node returns an acceptance message indicating acceptance of a restoration operation. The acceptance message can particularly be a cell de-compensation response. The cell de-compensation response includes the identifiers of cells accepting activation, that is, any cell without its corresponding cell identifier being carried will not accept a restoration operation, so a failure message as returned below may not carry a cell identifier. The cell de-compensation response can further include cell types, cell sizes and other information.
[0178] Step 1405 : The energy-saving node returns a failure message indicating rejection of a restoration operation. The failure message can particularly be a cell de-compensation failure. The cell de-compensation failure may carry information indicating a reason for rejection of a restoration operation.
[0179] Step 1406 : The compensation node determines a cell to be finally activated from a preset adjustment strategy upon reception of the acceptance message. Numerous adjusting strategies are possible, for example, the number of users and the amount of data acceptable to switch together with cells where this part of users reside are determined from the number of local users, the amount of local data and the received cell types, sizes and other information. Particularly the adjustment strategy can be configured by an OAM entity or can be exchanged between cells.
[0180] Step 1407 : The compensation node sends a cell activation request to the energy-saving node. The cell activation request carries the cell identifier of the cell to be finally activated.
[0181] Step 1408 : The energy-saving node quits an energy-saving state, performs an activation operation and restores a service of the cell accepting activation upon reception of the cell activation request.
[0182] Step 1409 : The compensation node switches a user to the activated energy-saving cell. If there is a user, served by the compensation node, to be switched, then this step will be performed; otherwise, this step will be skipped. For whether to switch a user, reference can be made to the specification regarding a handover decision in the communication protocol.
[0183] Step 1410 : The energy-saving node admits the switched-in user.
[0184] Step 1411 : The compensation node quits a compensation state and narrows a coverage area. For example, a particular operation is to lower transmission power, to adjust an inclination angle of an antenna, etc.
[0185] Step 1412 : For the narrowed cell, the compensation node interacts with new adjacent cells and collects RLF and other related information of the new adjacent cells on as to further adjust transmission power and optimize the coverage area.
[0186] Step 1413 : The compensation node operates as it is upon reception of the failure message.
[0187] To perform a coverage restoration operation, the operation can alternatively be initiated by the energy-saving node, and for a particular process, reference can be made to the following embodiments.
[0188] Referring to FIG. 15 , a flow of a method of an energy-saving node initiating coverage restoration in a forced process in this embodiment as follows:
[0189] Step 1501 : An energy-saving node determines from a preset energy-saving restoration strategy a coverage restoration process is to be initiated. Numerous preset energy-saving restoration strategies are possible, for example, a preset point of time is reached, e.g., 7 a.m. Other energy-saving restoration strategies are also possible and will not be enumerated here so as to avoid a repeated description, and any energy-saving restoration strategy with a coverage restoration process to be initiated can be applicable to this embodiment. Particularly the energy-saving restoration strategy can be preconfigured by an OAM entity or can be exchanged between cells.
[0190] Step 1502 : The energy-saving node sends a de-compensation request to a compensation node to request the compensation node for provision of coverage restoration. The de-compensation request can particularly be a cell de-compensation indication. The cell de-compensation indication carries the identifiers of target cells requested to be activated and can further include a maximum period of time within which a target cell is activated. Particularly the energy-saving node can send the de-compensation request to the compensation node directly via an X2 interface; or can have the de-compensation request transparently transmitted to the compensation node over a core network.
[0191] Step 1503 : The energy-saving node performs an activation operation and activates all the functions of a cell, served by the node, to be activated after sending the de-compensation request.
[0192] Step 1504 : The compensation node switches a user to the activated energy-saving cell upon reception of the de-compensation request. If there is a user, served by the compensation node, to be switched, then this step will be performed; otherwise, this step will be skipped. For whether to switch a user, reference can be made to the specification regarding a handover decision in the communication protocol.
[0193] Step 1505 : The compensation node quits a compensation state and narrows a coverage area. For example, a particular operation is to lower transmission power, to adjust an inclination angle of an antenna, etc.
[0194] Step 1506 : For the narrowed cell, the compensation node interacts with new adjacent cells and collects RLF and other related information of the new adjacent cells so as to further adjust transmission power and optimize the coverage area.
[0195] Step 1507 : The energy-saving node admits the switched-in user.
[0196] Referring to FIG. 16 , a flow of a method of an energy-saving node initiating coverage restoration in a one-negotiation process in this embodiment is as follows:
[0197] Step 1601 : An energy-saving node determines from a preset energy-saving restoration strategy a coverage restoration process is to be initiated.
[0198] Step 1602 : The energy-saving node sends a de-compensation request to a compensation node to request the compensation node for provision of coverage restoration. The de-compensation request can particularly be a cell de-compensation request. The cell de-compensation request carries the identifiers of target cells requested to be activated and can further include a maximum period of time within which a target cell is activated, information related to the target cells, etc. A variety of information related to the target cells is possible, cell types, cell sizes, etc.
[0199] Step 1603 : The compensation node determines whether to agree on coverage restoration from a local compensation restoration strategy and the received information related to the target cells, and if so, then the flow proceeds to the step 1604 ; otherwise, the flow proceeds to the step 1610 . Particularly the compensation restoration strategy can be preconfigured by an OAM entity or can be exchanged between cells. Numerous compensation restoration strategies are possible, for example, it is determined whether the size of a target cell satisfies a demand of a user and the amount of data to be switched and whether the type of the target cell satisfies a service demand of the user, and if both are positive, then the compensation nodes agrees on coverage restoration. Other compensation restoration strategies are also possible and will not be enumerated here so as to avoid a repeated description thereof.
[0200] Step 1604 : The compensation node returns an acceptance message indicating acceptance of a coverage restoration operation. The acceptance message can particularly be a cell de-compensation response. The cell de-compensation response includes the identifier of a cell accepting activation, that is, any cell without its corresponding cell identifier being carried will not provide a coverage restoration operation, so a failure message as returned below may not carry a cell identifier.
[0201] Step 1605 : The energy-saving node quits an energy-saving state, performs an activation operation and restores a service of the cell accepting activation upon reception of the acceptance message.
[0202] Step 1606 : The compensation node switches a user to the activated energy-saving cell. If there is a user, served by the compensation node, to be switched, then this step will be performed; otherwise, this step will be skipped. For whether to switch a user, reference can be made to the specification regarding a handover decision in the communication protocol.
[0203] Step 1607 : The compensation node quits a compensation state and narrows a coverage area. For example, a particular operation is to lower transmission power, to adjust an inclination angle of an antenna, etc.
[0204] Step 1608 : For the narrowed cell, the compensation node interacts with new adjacent cells and collects RLF and other related information of the new adjacent cells so as to further adjust transmission power and optimize the coverage area.
[0205] Step 1609 : The energy-saving node admits the switched-in user.
[0206] Step 1610 : The energy-saving node returns a failure message indicating rejection of a coverage restoration operation. The failure message can particularly be a cell de-compensation failure. The cell de-compensation failure may carry information indicating a reason for rejection of a coverage restoration operation.
[0207] Step 1611 : The compensation node operates as it is upon reception of the failure message.
[0208] Referring to FIG. 17 , a flow of a method of an energy-saving node initiating coverage restoration in a two-negotiation process in this embodiment is as follows:
[0209] Step 1701 : An energy-saving node determines from a preset energy-saving restoration strategy a coverage restoration process is to be initiated.
[0210] Step 1702 : The energy-saving node sends a de-compensation request to a compensation node to request the compensation node for provision of coverage restoration. The de-compensation request can particularly be a cell de-compensation request.
[0211] Step 1703 . The compensation node determines whether to agree on coverage restoration from a local compensation restoration strategy and received information related to target cells, and if so, then the flow proceeds to the step 1704 ; otherwise, the flow proceeds to the step 1705 .
[0212] Step 1704 : The compensation node returns an acceptance message indicating acceptance of a coverage restoration operation. The acceptance message can particularly be a cell de-compensation response. The cell de-compensation response includes the identifiers of cells accepting activation, that is, any cell without its corresponding cell identifier being carried will not provide a coverage restoration operation, so a failure message as returned below may not carry a cell identifier. The cell de-compensation response can further include the number of users, the amount of data to be switched and other information.
[0213] Step 1705 : The compensation node returns a failure message indicating rejection of a coverage restoration operation. The failure message can particularly be a cell de-compensation failure. The cell de-compensation failure may carry information indicating a reason for rejection of a coverage restoration operation.
[0214] Step 1706 : The energy-saving node determines a cell to be finally activated from a preset adjustment strategy upon reception of the acceptance message. Numerous adjusting strategies are possible, for example, the number of users and the amount of data acceptable to switch together with cells where this part of users reside are determined from the received number of local users and amount of data to be switched and local cell types and cell sizes. Particularly the adjustment strategy can be configured by an OAM entity or can be exchanged between cells.
[0215] Step 1707 : The energy-saving node sends a cell activation request to the compensation node. The cell activation request carries the cell identifier of the cell to be finally activated.
[0216] Step 1708 : The energy-saving node quits an energy-saving state, performs an activation operation and restores all the functions of the cell, served by the node, to be finally activated after sending the cell activation request.
[0217] Step 1709 : The compensation node sends a de-compensation request to another non-requesting energy-saving node upon reception of the cell activation request to instruct the other energy-saving node to activate a cell. The de-compensation request can be a cell de-compensation indication or a cell de-compensation request. For operations of the other energy-saving node upon reception of the de-compensation request, reference can be made to the flows illustrated in FIG. 12 to FIG. 14 , i.e., the compensation restoration flows initiated by the compensation node. In this step, primarily in view of that the compensation node may have omni-directional coverage, when some cell or cells are provided with coverage restoration, its narrowed coverage area may not cover a non-requesting cell or cells and a restoration operation can also be performed on this part of cells to reduce or avoid a coverage hole from occurring. Of course the second negotiation in this embodiment includes negotiation between the compensation node and the other energy-saving node.
[0218] Step 1710 : The compensation node switches a user to the activated energy-saving cell upon reception of the cell activation request. If there is a user, served by the compensation node, to be switched, then this step will be performed; otherwise, this step will be skipped. For whether to switch a user, reference can be made to the specification regarding a handover decision in the communication protocol.
[0219] Step 1711 : The compensation node quits a compensation state and narrows a coverage area. For example, a particular operation is to lower transmission power, to adjust an inclination angle of an antenna, etc.
[0220] Step 1712 : For the narrowed cell, the compensation node interacts with new adjacent cells and collects RLF and other related information of the new adjacent cells so as to further adjust transmission power and optimize the coverage area.
[0221] Step 1713 : The energy-saving node admits the switched-in user.
[0222] Step 1714 : The energy-saving node operates as it is upon reception of the failure message.
[0223] To perform a coverage restoration operation, a device initiating the coverage restoration operation will not be limited to a compensation node and an energy-saving node, but the operation can also be initiated by a third-party device, e.g., an OAM entity, and for a particular process, reference can be made to the following embodiments.
[0224] Referring to FIG. 18 , a method of an OAM entity initiating coverage restoration in a forced process in this embodiment is as follows:
[0225] Step 1801 : An OAM entity collects coverage information, load information, etc., of a compensation node and an energy-saving node. This is only exemplary, and the OAM entity can collect any de-compensation related information. This step can be performed periodically or at fixed timings or under some trigger condition.
[0226] Step 1802 : The OAM entity determines from preset de-energy-saving and de-compensation strategies a coverage restoration process is to be initiated. The preset de-energy-saving and de-compensation strategies can include the compensation restoration strategy of the compensation node in FIG. 12 to and/or the de-energy-saving strategy of the energy-saving node in FIG. 15 to FIG. 17 .
[0227] Step 1803 : The OAM entity triggers dynamically the compensation node to activate a de-compensation state and the energy-saving node to activate a de-energy-saving state. The OAM entity can trigger the de-compensation state and the de-energy-saving state particularly by sending a de-compensation request to the compensation node and the energy-saving node. The de-compensation request can particularly be a cell de-compensation indication or another configuration message.
[0228] Step 1804 : The energy-saving node quits an energy-saving state, performs an activation operation and restores a service of a cell accepting activation after being triggered.
[0229] Step 1805 : The compensation node switches a user to the activated energy-saving cell. If there is a user, served by the compensation node, to be switched, then this step will be performed; otherwise, this step will be skipped. For whether to switch a user, reference can be made to the specification regarding a handover decision in the communication protocol.
[0230] Step 1808 : The energy-saving node admits the switched-in user.
[0231] Step 1807 : The compensation node quits a compensation state and narrows a coverage area. For example, a particular operation is to lower transmission power, to adjust an inclination angle of an antenna, etc.
[0232] Step 1808 : For the narrowed cell, the compensation node interacts with new adjacent cells and collects RLF and other related information of the new adjacent cells so as to further adjust transmission power and optimize the coverage area.
[0233] Referring to FIG. 19 , a flow of a method of initiating a coverage restoration process automatically after an OAM entity pre-configures energy-saving and compensation strategies is as follows:
[0234] Step 1901 : An OAM entity configures a temporal strategy to a compensation node and an energy-saving node. The temporal strategy can be timings or can be periodical. For example, in a timing temporal strategy, the compensation node quits/enters a compensation state again three hours after entering/quitting the compensation state, and also the related energy-saving node is activated/deactivated three hours after being deactivated/activated. For example, in a periodical temporal strategy; the compensation node enters/quits a compensation state for a period of time of 0:00 to 7:00, and also a period of time for which the related energy-saving node enters/quits an energy-saving state can be set the same as 0:00 to 7:00. In this embodiment, the temporal strategy can be regarded as an energy-saving or compensation strategy or a part thereof.
[0235] After the temporal strategy is configured once, the following steps can be performed repeatedly.
[0236] Step 1902 : The energy-saving node quits an energy-saving state, performs an activation operation and restores a service of a cell accepting activation when the temporal strategy is satisfied.
[0237] Step 1903 : The compensation node switches a user to the activated energy-saving cell. If there is a user, served by the compensation node, to be switched, then this step will be performed; otherwise, this step will be skipped. For whether to switch a user, reference can be made to the specification regarding a handover decision in the communication protocol.
[0238] Step 1904 : The energy-saving node admits the switched-in user.
[0239] Step 1905 : The compensation node quits a compensation state and narrows a coverage area. For example, a particular operation is to lower transmission power, to adjust an inclination angle of an antenna, etc.
[0240] Step 1906 : For the narrowed cell, the compensation node interacts with new adjacent cells and collects RLF and other related information of the new adjacent cells so as to further adjust transmission power and optimize the coverage area.
[0241] The foregoing introduction has been made of the coverage area compensation and restoration processes generally involving the compensation node, the energy-saving and the OAM entity, and internal structures and functions of these apparatuses will be introduced below.
[0242] Referring to FIG. 20 , a coverage area compensation apparatus in this embodiment includes a strategy module 2001 and enforcement module 2002 .
[0243] The strategy module 2001 is configured to determine from preset energy-saving and compensation strategies whether a trigger condition to initiate an energy-saving and compensation process is satisfied or to receive a trigger for the energy-saving and compensation process from an OAM entity.
[0244] The enforcement module 2002 is configured to perform an energy-saving operation in the energy-saving and compensation process or to perform a compensation operation in the energy-saving and compensation process when the energy-saving and compensation process is determined to be initiated. Preferably the enforcement module 2002 performs the energy-saving operation in the energy-saving and compensation process after a preset minimum period of time after which a target cell is deactivated or performs the compensation operation in the energy-saving and compensation process within the preset minimum period of time after which a target cell is deactivated. The enforcement module 2002 performs the compensation operation at least in any one of the following ways:
[0245] A coverage area is enlarged by adjusting power of an antenna;
[0246] A coverage area is enlarged by adjusting the number of antenna ports; and
[0247] A coverage area is enlarged by adjusting an inclination angle of an antenna.
[0248] The enforcement module performs the energy-saving operation by deactivating all the other functions than a sounding function in a cell.
[0249] Particularly the apparatus is an energy-saving node when performing the energy-saving operation in the energy-saving and compensation process; and the apparatus is a compensation node when performing the compensation operation in the energy-saving and compensation process.
[0250] The apparatus further includes an interface module 2003 as illustrated in FIG. 21 . The face module 2003 is configured to send a compensation request to a second node to trigger the second node to perform an energy-saving and compensation process.
[0251] The interface module 2003 is further configured to receive a cell compensation response returned from the second node. The enforcement module 2002 performs the energy-saving operation in the energy-saving and compensation process or performs the compensation operation in the energy-saving and compensation process according to the cell compensation response. Alternatively the strategy module 2001 is further configured to determine a cell for which energy-saving is finally required from the cell compensation response and an adjustment strategy upon reception of the cell compensation response. The interface module 2003 is further configured to send to the second node a cell deactivation request carrying the cell identifier of the cell to be finally deactivated.
[0252] When the apparatus is a compensation node, the interface module 2003 is further configured to send a cell deactivation request to an adjacent energy-saving node other than the second node upon reception of the cell compensation response.
[0253] The interface module 2003 is further configured to receive a cell compensation failure returned from the second node.
[0254] When the apparatus is a party receiving a compensation request, the strategy module 2001 is further configured to determine whether to agree on energy-saving from the preset energy-saving and compensation strategies and enlarged coverage related information in a compensation request upon reception of the compensation request. The interface module 2003 is configured to return a compensation response when energy-saving is agreed on. The interlace module 2003 is further configured to return a cell compensation failure when energy-saving is rejected. The interface module 2003 is further configured to receive a cell deactivation request after returning the cell compensation response.
[0255] The apparatus further includes a switch module 2004 configured to receive a user switched in from a target cell to be deactivated or to switch the user from the target cell to be deactivated to another cell.
[0256] Referring to FIG. 22 , a coverage area restoration apparatus in this embodiment includes a strategy module 2201 and enforcement module 2202 .
[0257] The strategy module 2201 is configured to determine from preset energy-saving and compensation restoration strategies whether a trigger condition to initiate a coverage restoration process is satisfied or to receive a trigger for the coverage restoration process from an OAM entity.
[0258] The enforcement module 2202 is configured to perform an energy-saving restoration operation in the coverage restoration process or a compensation restoration operation in the coverage restoration process when an energy-saving and compensation process is determined to be initiated. Preferably the enforcement module 2202 performs the energy-saving restoration operation in the coverage restoration process within a preset maximum period of time within which a target cell is activated or performs the compensation restoration operation in the coverage restoration process after the preset maximum period of time within which a target cell is activated.
[0259] The enforcement module 2202 performs the compensation restoration operation at least in any one of the following ways:
[0260] A coverage area is narrowed by adjusting power of an antenna;
[0261] A coverage area is narrowed by adjusting the number of antenna ports; and
[0262] A coverage area is narrowed by adjusting an inclination angle of an antenna.
[0263] The enforcement module 2202 performs the energy-saving restoration operation by activating all the deactivated functions in a cell.
[0264] Particularly the apparatus is an energy-saving node when performing the energy-saving restoration operation in the energy-saving and compensation restoration process; and the apparatus is a compensation node when performing the compensation restoration operation in the energy-saving and compensation restoration process.
[0265] The apparatus further includes an interface module 2203 as illustrated in FIG. 23 . The interface module 2203 is configured to send a de-compensation request to a second node to trigger the second node to perform an energy-saving and compensation restoration process.
[0266] The interface module 2203 is further configured to receive a cell de-compensation response returned from the second node. The enforcement module 2202 performs the energy-saving restoration operation in the energy-saving and compensation restoration process or performs the compensation restoration operation in the energy-saving and compensation restoration process according to the cell de-compensation response. Alternatively the strategy module 2201 is further configured to determine a cell to be finally activated from the cell de-compensation response and an adjustment strategy upon reception of the cell de-compensation response. The interface module 2203 is further configured to send to the second node a cell activation request carrying the cell identifier of the cell to be finally activated.
[0267] When the apparatus is a compensation node, the interface module 2203 is further configured to send a cell activation request to an adjacent energy-saving node other than the second node upon reception of the cell de-compensation response.
[0268] The interface module 2203 is further configured to receive a cell de-compensation failure returned from the second node.
[0269] When the apparatus is a party receiving a de-compensation request, the strategy module 2201 is further configured to determine whether to agree on restoration from the preset energy-saving and compensation restoration strategies and received narrowed coverage related information upon reception of the de-compensation request and to return a de-compensation response upon agreement on restoration.
[0270] The interface module 2203 is further configured to return a cell de-compensation failure when restoration is rejected.
[0271] The interface module 2203 is further configured to receive a cell deactivation request after returning the cell de-compensation response.
[0272] The apparatus further includes a switch module 2204 configured to switch a user to a target cell to be activated or to admit a switched-in user.
[0273] In this embodiment, the coverage area energy-saving apparatus and the coverage area restoration apparatus can be the same apparatus which performs an energy-saving function when energy-saving is required and performs a restoration function when restoration is required. The strategy module 2001 and the strategy module 2201 are the same module, the enforcement module 2002 and the enforcement module 2202 are the same module, the interface module 2003 and the interface 2203 are the same module, and the switch module 2004 and the switch module 2204 are the same module.
[0274] Referring to FIG. 24 , an OAM entity in this embodiment includes a strategy module 2401 and an interface module 2402 .
[0275] The strategy module 2401 is configured to determine from preset energy-saving and compensation strategies whether a trigger condition to initiate an energy-saving and compensation process is satisfied.
[0276] The interface module 2402 is configured to trigger a first node and a second node to perform the energy-saving and compensation process when the energy-saving and compensation process is determined to be initiated. The interface module 2402 is further configured to collect coverage information and load information of the first node and the second node.
[0277] Particularly the first node is a compensation node, and the second node is an energy-saving node; or the first node is an energy-saving node, and the second node is a compensation node.
[0278] Referring to FIG. 25 , an OAM entity in this embodiment includes a strategy module 2501 and an interface module 2502 .
[0279] The strategy module 2501 is configured to determine from preset energy-saving and compensation restoration strategies whether a trigger condition to initiate a coverage restoration process is satisfied.
[0280] The interface module 2502 is configured to trigger a first node and a second node to perform an energy-saving and compensation restoration process when the coverage restoration process is determined to be initiated. The interface module 2502 is further configured to collect load information and coverage information of the first node and the second node.
[0281] Particularly the first node is a compensation node, and the second node is an energy-saving node; or the first node is an energy-saving node, and the second node is a compensation node.
[0282] The OAM entity in FIG. 24 and the OAM entity in FIG. 25 can be the same apparatus which performs an energy-saving function when energy-saving is required and performs a restoration function when restoration is required. The strategy module 2401 and the strategy module 2501 are the same module, and the interface module 2402 and the interface 2502 are the same module.
[0283] A node in an embodiment of the invention sends a compensation request to another related node when an energy-saving or compensation strategy is satisfied so that the node sending the request and the other related node perform an energy-saving or compensation operation to implement energy-saving and compensation between the nodes. Various implementations are provided in embodiments of the invention, so that a de-energy-saving or restoration process can be initiated by a compensation node, an energy-saving node or an OAM entity, and a forced or negotiation process can be performed between the compensation node and the energy-saving node to accommodate a demand in different scenarios.
[0284] Those skilled in the art shall appreciate that the embodiments of the invention can be embodied as a method, a system or a computer program product. Therefore the invention can be embodied in the form of an all-hardware embodiment, an all-software embodiment or an embodiment of software and hardware in combination. Furthermore the invention can be embodied in the form of a computer program product embodied in one or more computer useable storage mediums (including but not limited to a disk memory, an optical memory, etc.) in which computer useable program codes are contained.
[0285] The invention has been described in a flow chart and/or a block diagram of the method, the device (system) and the computer program product according to the embodiments of the invention, it shall be appreciated that respective flows and/or blocks in the flow chart and/or the block diagram and combinations of the flows and/or the blocks in the flow chart and/or the block diagram can be embodied in computer program instructions. These computer program instructions can be loaded onto a general-purpose computer, a specific-purpose computer, an embedded processor or a processor of another programmable data processing device to produce a machine so that the instructions executed on the computer or the processor of the other programmable data processing device create means for performing the functions specified in the flow(s) of the flow chart and/or the block(s) of the block diagram.
[0286] These computer program instructions can also be stored into a computer readable memory capable of directing the computer or the other programmable data processing device to operate in a specific manner so that the instructions stored in the computer readable memory create an article of manufacture including instruction means which perform the functions specified in the flow(s) of the flow chart and/or the block(s) of the block diagram.
[0287] These computer program instructions can also be loaded onto the computer or the other programmable data processing device so that a series of operational steps are performed on the computer or the other programmable data processing device to create a computer implemented process so that the instructions executed on the computer or the other programmable device provide steps for performing the functions specified in the flow(s) of the flow chart and/or the block(s) of the block diagram.
[0288] Evidently those skilled in the art can make various modifications and variations to the invention without departing from the spirit and scope of the invention. Thus the invention is also intended to encompass these modifications and variations thereto so long as the modifications and variations come into the scope of the claims appended to the invention and their equivalents.
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Disclosed is a method for compensation and restoring of a coverage area, for realizing energy saving and compensation between nodes. The coverage compensation method includes: judging whether or not the trigger condition for starting an energy saving and compensation process is satisfied according to a preset energy saving and compensation strategy; when the trigger condition for starting the energy saving and compensation process is satisfied, one of a first node and a second node carries out an energy saving operation in the energy saving and compensation process while the other node carries out a compensation operation in the energy saving and compensation process; wherein the first node is a compensation node and the second node is an energy saving node, or the first node is an energy saving node and the second node is a compensation node. Further disclosed is a device for implementing the method.
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