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This is a continuation of application Ser. No. 871,736, filed June 6, 1986, now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to methods for the determination of the amino acid sequence of polypeptides and proteins, and equipment for making such determinations.
The most widely used method of protein sequence analysis is the Edman degradation for the sequential removal of amino acid residues. In this scheme, amino acids are removed from the N-terminal of the peptide in a two-step chemical process. The operation for one cleavage is illustrated below. ##STR1##
In the first step an activating group, termed a coupling reagent and illustrated by phenylisothiocyanate in the above diagram, is attached to the free amino group of the N-terminal amino acid of the polypeptide, the sequence of which is to be determined. This step is called coupling and is carried out in a buffer containing a coupling base at high pH (pH 8-9). The Edman process typically uses phenylisothiocyanate (PITC) as a coupling reagent. Other reagents such as methylisothiocyanate or penta-fluorophenylisothiocyanate have been used 1 ,2. The function of the coupling reaction is to make the peptide, bond between the first and second residues more easily acid hydrolyzed than any of the other peptide bonds in the protein. After removal of excess coupling reagent and buffer, the second step is the addition of a cleavage reagent, anhydrous acid, to hydrolyze this activated peptide bond The cleaved amino acid derivative can then be extracted with a suitable organic solvent. The residual peptide with the newly formed N-terminal is left behind for subsequent cycles. The extracted derivative contains information on the identity of the initial N-terminal residue since the amino acid is incorporated in its structure. By differentiating the twenty or so derivatives on the basis of their side chain (R 1 ), the derivative formed after each cleavage can be identified and the amino acid ascertained. If this process is repeated, each subsequent residue can ideally be determined. However, it is not practical to carry out repetitive chemical reactions indefinitely, since the coupling and cleavage reactions never attain 100% yield Although the coupled N-terminal peptide bond is more susceptible to acid hydrolysis than any other bond, random cleavage can and does occur.
The Edman process has been used in manual methods and in automated methods for amino acid sequence determination.
The manual procedures are most frequently used for sequence determinations of small peptides on short sections of proteins or when the cost of an automated sequencer cannot be justified. Many such methods have been reported 3 ,5. Most approaches first apply the protein or peptide to a support such as a paper strip. After the sample is dried, phenylisothiocyanate in a solvent-buffer system (i.e. dioxane or pyridine, etc.) is introduced to the immobilized peptide The coupling reaction may take several hours at 40°-50° C. for completion. It is important at this step that oxygen be excluded to prevent blocking of the N-terminal via side reactions. After coupling is complete, the excess reagents (PITC, etc.) and byproducts (i.e. diphenyl-thiourea) are removed without loss of PTC (phenylthiocarbamyl)-peptides. Several solvent systems have been suggested for this step (.e.g benzene alcohol-ether) 6 . Extraction with benzene alone to remove these byproducts is slow but it does not remove coupled peptides. Either ethyl acetate or an alcohol-ether mixture is better for removing the byproducts but these will also extract small hydrophobic peptides.
After the first wash the PTC-peptide is cleaved into the thiazolinone amino acid and a free peptide. Since internal peptide bond cleavage can occur under aqueous conditions 7 , most procedures call for anhydrous acid, such as trifluoroacetic or heptafluorobutyric acid. During this step the reaction is carried out at a lower temperature than when coupling, and water is excluded from the sample chamber. The cleavage of coupled residues is more difficult with prolyl or glycyl residues, and these may require a higher temperature or a longer reaction period. Overly vigorous hydrolysis conditions at this point can lead to spurious cleavage of internal peptide bonds.
In the final step, the 2-anilino-t-thiazolinone amino acid (ATZ) is extracted with benzene and ethyl acetate. The phase transfer is quantitative for most amino acid derivatives except ATZ-Arg and ATZ-His. Ethyl acetate alone will give better extraction of ATA-Arg and ATZ-His but may also extract small hydrophobic peptides. Acetone is a satisfactory compromise if all traces of water and the acid cleavage reagent are removed earlier by drying under vacuum. The extracted ATZ-amino acid is unstable and must be converted to the stable PTH (3-phenyl-2-thiohydantoin) form by aqueous hydrolysis. The method of Edman is generally used. The conversion reaction consists of hydrolysis of the thiazolinone to the PTC-amino acid intermediate followed by rearrangement to the PTH form. The benzene/ethyl acetate extract is evaporated to dryness under a stream of nitrogen and then dissolved in dilute HCL. The temperature is quickly brought to 80° C. and maintained for 10 minutes, then lowered. The solution is dried and dissolved in a small volume of buffer, whereafter the PTH-amino acid derivative is analyzed.
In general, amino acid sequence determinations are made by automated methods in equipment dedicated to that purpose. The chemistry employed in such automated methods is basically the same as that used in the manual procedure. Present automatic sequencers are based on either the liquid phase (spinning cup) or phase designs. In the liquid phase instruments, protein sample is spread out as a thin film on the inner wall of a rotating reaction cup. The protein is immobilized while liquid Edman reagents introduced into the reaction cup at the bottom move up over the protein film by centrifugal force. Liquids are removed from the top of the cup by means of a scoop protruding into a groove around the top of the cup.
A description of the spinning cup sequencer is given in the original paper by Edman and Begg 7 . In the operation of such sequencers a solution of the sample is introduced into the cup and dried under vacuum while the cup is turning, thus forming a thin film on the lower walls of the cup. Sample size is generally around 100 to 300 nanomoles of sample dissolved in about 500 microliters of the appropriate solvent. After the sample has been dried the automatic cycle is started.
The first step is the introduction of coupling reagent (5% PITC in heptane) and buffer into the spinning reaction cup. The buffer generally contains N,N-dimethyl-N-allylamine (DMAA) to maintain the alkaline pH needed for the coupling reaction. A suitable buffer containing DMAA and a detergent is sold under the trademark Quadrol. The coupling mixture spreads out over the Protein film and dissolves it. The ensuing reaction proceeds for about 20 minutes at 55° C. After partial removal of PITC and solvent by vacuum, the coupling reaction is stopped by the introduction of benzene. The benzene precipitates the protein and carries off the excess PITC reagent and some of the breakdown products of PITC. If Quadrol is used as the buffer, the cup is washed with ethylacetate to remove excess buffer and more of the breakdown products. After vacuum drying the protein remains in the cup as a white film
Anhydrous heptafluorobutyric acid (HFBA) is added to initiate cleavage. The volatile HFBA covers and dissolves the protein film and after only two to three minutes the N-terminal amino acid is cleaved as the anilinothioazolinone derivative. Finally, the remaining HFBA is removed by vacuum, then the released ATZ-amino acid is extracted with butyl chloride and delivered to a fraction collector. A new residue is released to the fraction collector with each cycle of the above procedure.
The collected fractions of ATZ-amino acids now represent the sequential order of amino acid residues comprising the peptide or protein sample. The fractions can be converted to the more stable PTH-amino acid products The solution is heated for 10 minutes in 1.0M HCl at 80° C. or 25% TFA (trifluoroacetic acid) in H 2 O at 60° C. After removal from heat all PTH-amino acid derivatives except PTH-Arg and PTH-His can be extracted with ethyl acetate. Liquid chromatography analysis at this stage is advantageous since there is no need to separate the two phases: All PTH-amino acids present can be determined in a single injection. For preconcentration purposes, the fraction is usually taken to dryness at low temperature prior to the chromatography.
The spinning cup sequencer suffers from the disadvantages of requiring the delivery of precisely calibrated reagent quantities, else protein is easily washed from the cup, the protein must be continuously cycled through successive precipitations and resolubilizations, leading to protein loss and denaturation, and extenders such as Polybrene or blocked proteins are often required to aid in the precipitation of the test sample. The disadvantage of proteinaceous extenders is that they are frequently hydrolyzed during cycles of Edman degradation. These hydrolyzed extenders contain free amino termini that are sequenced along with the test sample, thereby introducing interfering residues into the determination.
Automatic solid-phase sequencers perform the Edman degradation on peptides in much the same way as liquid-phase systems, except that the peptide is immobilized by covalent attachment to a solid support material and does not undergo cycles of solubilization and precipitation Reagents and solvents are undirectionally pumped through a column of bound peptide as required. In this type of sequencer the sample peptide first must be covalently linked to the support material. Several methods have been reported for achieving this task. The most reliable coupling procedures utilize the ε-amino group of lysine 10 or a C-terminal homoserine 15 . Coupling yields are usually up to about 80% but the peptide must contain lysine or a C-terminal carboxyl group 16 . The two types of solid supports for covalent coupling generally used are polystyrene 17 and porous glass 13 . Both are highly substituted with functional groups and inert to the reagents and solvents used in sequencing. Small peptides containing lysine are usually attached to aminopolystyrene by the diisothiocyanate coupling procedure. Peptides without lysine are attached to triethylenetetramine resin by carboxyl activation. Large peptides and proteins are affixed to amino glass supports after activation with diisothiocyanate 18 .
After peptide attachment the resin is washed and packed into a small glass column. The reaction column is then placed into a heated holder in the sequencer From this point, the solid-phase instrument follows much the same chemical procedure as the manual and spinning cup methods except that a wider range of reagents, buffers and solvents can be passed through the column without fear of washing out the covalently bound peptide. The routinely used solid-phase sequencing chemicals are: PITC (5% V/V in acetonitrile), pyridine: N-methylmorpholiniuatrifluoroacetate buffer (2:3 V/V), and trifluoroacetic acid. Ethylene dichloride and methanol are used as solvents. Fractions of the ATZ-amino acids are collected in a fraction collector and later converted to the PTH-amino acid derivative either manually or automatically as described before.
The solid phase sequencer using covalent immobilization of the test protein has never achieved widespread commercial acceptance. This is predominantly the result of the nature of the covalent immobilization, which requires specialized conditions for each polypeptide and results in protein losses.
The gas phase sequencer is related to the solid phase sequencer in that it uses preimmobilized polypeptide. However, rather than avoiding peptide loss by covalent immobilization, this system uses a gaseous form of the alkaline buffer coupling reagent to avoid elution of non-covalently adsorbed polypeptide. The gas phase sequencer has enjoyed considerable commercial success, supplanting both the spinning cup and solid phase sequencers.
An early version of a gas phase sequencer is described in U.S. Pat. No. 4,065,412. A commercial sequencer based upon the system described in that patent is sold by Applied Biosystems of Foster City, Calif. In that system, the protein or peptide is noncovalently deposited on a glass fiber disc which contains a protein extender (Polybrene). The protein and extender form an immobilized film in the glass fiber disc which is held in a small glass chamber. Gas and liquid Edman reagents enter through a small opening at the top of the chamber and exit through the bottom.
The coupling reagent is added in an organic solvent (heptane) that will not dislodge the peptide. The coupling reaction occurs after wetting of the entire surface of the glass disc with the coupling reagent solution and drying off the organic solvent. The reaction is started by introducing the gaseous coupling base, trimethylamine (TMA) The vapor stream of coupling base and water vapor increases the pH of the protein film. In contrast to the spinning cup sequencer, the sample chamber is small and simple. Since there is no liquid buffering solution, certain peptides may be sequenced without covalent attachment. However, this requires that the coupling reagent be added in an organic solvent and that the coupling base be introduced in a separate step. Furthermore, a disadvantage of using the gaseous coupling base is that the reaction is not as easily controlled as with a liquid buffer solution In solution, the optimum pH is approximately 9.0. At a pH higher than 9.5, the coupling reagent begins to react more rapidly with water to form byproducts (anilide and diphenylthiourea). At higher pH levels, breakdown of the peptide or protein can become a problem as set forth in the aforementioned U S. Pat. No. 4,065.412. To effectively control the pH on the reaction surface, the flow rate of the gaseous phase must be precisely controlled as well as the concentration of base (e.g., TMA) in the gaseous atmosphere. This requirement for precise control of flow rates and concentrations results in a very complex and expensive instrument that requires highly skilled operators. Total instrument temperature control is needed to ensure precisely calibrated reagent aliquots.
Another disadvantage of the gas phase system is the requirement that Polybrene (e g., in amounts of 1.2 mg) be used to retain the protein on the small glass disc. However, Polybrene also retains byproducts more efficiently. It has been reported that covalently linked peptides when sequenced in a gas phase sequencer without using Polybrene produce much less of the byproduct peak 19 . Large amounts of byproduct peaks can obscure the identification of some amino acid derivatives.
Another disadvantage of performing the reaction on the surface of the gas phase sequencer with little if any aqueous solvent is that small amounts of salts, denaturants such as urea, or buffer ions deposited from the test sample can interfere with the reaction of the alpha-amino of the N-terminal residue, or interfere with the solvent extraction of amino acid derivatives for identification or the washing out of undesired byproducts.
Another disadvantage of the gas phase sequencer is that after the coupling reaction is complete, all remaining water vapor must be removed by an inert gas drying. Then the byproducts are removed by flowing an organic solvent through the disc holding chamber. It is important that the flow of solvent be precisely controlled so as not to dissolve or dislodge any immobilized protein. Since the flow is in one direction only and there is no film reforming step in the process, any dissolved peptide is lost in the wash.
It has been conventional for quite a long time to prepare test samples for amino acid sequencing by separating polypeptides from one another or from contaminants through the use of dialysis membranes or high pressure liquid chromatography. However, such procedures have not been incorporated into amino acid sequencing devices, and in fact are considered undesirable because they result in the loss of sample.
Accordingly, it is an object of the invention to provide a sequencer which is less expensive than the sequencers of the prior art in not requiring finely calibrated fluid or gas delivery systems or complete instrument temperature control.
It is a further object of the invention to provide a sequencer which is simpler to use than the systems of the prior art, thereby enabling unskilled persons to operate the sequencer.
It is another object to provide a sequencer capable of a higher percentage repetitive yield than has heretofore been available, and thus which is capable of being employed for a larger number of cycles than prior art systems.
It is another object of the invention to provide a sequencer capable of use with contaminated peptides which have not been previously purified. This avoids protein losses in sample preparation and recovery procedures heretofore used with conventional sequencers. This means that over the combined process of sample preparation and sequencer operation far less polypeptide is required to obtain amino acid sequence.
Another object herein is to provide a system that requires a substantially lower cycle time by optimizing the reaction conditions for and selection of Edman reagents, and which provides for more precise control of the coupling reaction than is possible with commercially available gas phase sequencers.
It is an additional object to provide a system for performing sequencing chemistry in an inexpensive multiple column sequencer for simultaneously determining amino acid sequences on a plurality of test samples, i.e. it is the objective to be able to use inexpensive turret valves with low fluid delivery tolerances in sequencers.
It is still a further object to provide a system for amino acid sequencing wherein the polypeptide is not so denatured or modified as to be insoluble in aqueous reagents. Polypeptides that are allowed to freely associate with water can be more accurately sequenced because the amino terminus is not potentially folded into an insoluble matrix and thus is not inaccessible to the sequencing reagents.
Another object is to dispense with the expense and difficulty of working with protein extenders such as Polybrene.
Another object is to provide a device for amino acid sequencing in which the advantages of temperature control during amino acid sequencing reactions can be fully realized.
An additional object is to provide an amino acid sequencer having replacement sample chamber cassettes for convenience and ease of use.
Further objects and features of the invention will be apparent from the following description taken in conjunction with the accompanying drawings.
SUMMARY OF THE INVENTION
The objects of this invention are achieved by a revolutionary change in the way in which polypeptide test samples are handled in amino acid sequencing systems. Whereas heretofore the art has considered it to be essential that the test sample be rigidly immobilized during at least part of the treatment with liquid Edman reagents in order to prevent protein losses due to wash-out from the sample chamber, applicant has recognized that many advantages are achieved if the test sample is in fact free to migrate within the sequencer sample chamber and should not be immobilized or precipitated therein. Applicant has avoided sample wash-out that otherwise would attend non-immobilized polypeptide by two major changes in prior art liquid phase sequencers. First, the improved sequencer is capable of multi-directional flow through the sample chamber. This permits reagents to be introduced serially at opposed ports in the sample chamber whereby the test sample migrates first in one direction with one solvent and then in the opposite direction by another solvent.
Second, in a preferred embodiment the sample chamber also contains a plurality of discrete adsorbents for the polypeptide tandemly arrayed in the solvent flow path through the chamber. The adsorbents are chosen so that the polypeptide sample partitions between a first adsorbent and solvent differently than between a second adsorbent and the same solvent. This means that a given polypeptide will migrate more slowly through the chamber (and its tandem adsorbents) in one direction than in another when the chamber is eluted with a given solvent. This is combined with the multi-directional flow embodiment described above to focus water soluble polypeptide in a band within the chamber that is poised between the chamber ports, i e. it migrates to and fro within the chamber as sequencing reagents are introduced but, because of the use of multiple adsorbents of opposed characteristics and multidirectional flow, the sample is not washed out of the sample chamber.
According to a preferred embodiment of the present invention I provide a polypeptide sequencer comprising (a) a flow-through sample chamber defining a fluid flow path and having first and second ports along the flow path, (b) chromatographic medium disposed in said sample chamber along the flow path, and (c) means for the sequential introduction of fluid reagents alternately to said first and second ports, whereby fluid reagents may be passed sequentially in opposite directions along said chromatographic medium flow path.
In the preferred embodiment, the sample chamber contains a tandem array of distinct adsorbents having differing solid phase. solvent partitioning properties with respect to the sample polypeptide. This is used together with multidirectional flow to suspend the polypeptide within the sample chamber.
A preferable chromatographic medium includes two discrete chromatographic medium segments in tandem of differing chromatographic properties, most preferably one hydrophilic and the other hydrophobic.
A convenient feature of the sequencer of this invention is that the sequencing reactions are performed in a container having first and second ports and disposed therein within the fluid flow path a plurality of discontinuous adsorbents, preferably chromatography resins, in tandem array in the fluid flow path.
In an exemplary method, water soluble peptide is deposited onto the chromatographic medium and migrated to the interface between the segments. The sample then is contacted with coupling reagent and coupling base flowing in a first direction to conjugate the coupling reagent to the peptide. Then a liquid washing solvent is flowed in the substantially opposite direction to remove unreacted coupling reagents and contaminants. Thereafter, cleavage reagent flows through the reaction in the first direction to cleave amino acid derivatives from the coupled peptides. Then, a liquid extracting solvent is flowed through the sample chamber in the second direction to extract and withdraw the cleaved amino acid while leaving the remaining peptide poised in the chromatographic medium. In all of the foregoing liquid elutions the direction of the flow is chosen so that the polypeptide migrates from a "fast" resin into a "slow" resin for the solvent concerned. A "fast" resin is one in which the polypeptide partitions to a greater extent into the solvent phase and therefore migrates through the resin more quickly than through the "slow" resin, which has a higher affinity for the polypeptide in the same solvent The amino acid derivative is then withdrawn and analyzed and the procedure is repeated for successive amino acid derivatives. The flow reversal permits migratory chromatofocusing of the peptide in the sample chamber.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic representation of a bidirectional flow, biphasic resin sequencer for use in the present invention.
FIGS. 2a-2e illustrate the steps performed in using the inventive device herein with the Edman sequencing method.
FIG. 3 illustrates a cut-away view of the symmetrical end of preferred cassette or cartridge sample chamber for use in the sequencer herein.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is directed generally to sequencing proteins or peptides by repeated cycles of attaching coupling reagent to a terminal amino acid and cleaving the coupled amino acid derivatives. For simplicity of description, the term peptide will include both peptides and proteins as sample materials. The invention is particularly adapted to the basic Edman procedure set forth in the background. The present application will refer to that procedure. However, it should be understood that by appropriate modification, the method is also applicable to other sequencing procedure which includes the same functional steps.
Referring to FIG. 1 a sequencer suitable for use in the present invention is illustrated. Aqueous sample solution containing peptide is injected through injection valve 10, such as is supplied suitably by a syringe. Sample solution through line 12a to line 12 which loads flow-through sample chamber 14 manually or automatically via flow-through port 16 disposed at one end of chamber 14. Chamber 14 preferably is in the form of an elongate flow-through column which is transparent to light (e.g., formed of glass). The total volume of the chamber can be varied but is generally about 0.20 ml including about 20 to 40 mg of dry glass beads. Chamber 14 contains chromatographic medium 18 having at least distinct first chromatographic medium segment 18a and second chromatographic medium segment 18b of differing chromatographic properties in fluid communication with each other along the flow path of the column. Segments 18a and 18b preferably are in tandem and abut each other to form an interface. Medium 18a is preferably hydrophilic, while medium 18b is preferably hydrophobic. Other suitable chromatographic media include Synchhropak AX300, Q300, CM300, or S300, which are amion and cation exchange HPLC supports.
In the illustrated embodiment, the lower stationary phase, chromatographic medium 18a is hydrophilic in the form of a normal phase HPLC medium. It should have a long retention time for the hydrophilic group of the peptide and a low affinity for the hydrophobic side products of the Edman reaction. Controlled-pore glass (e.g., supplied by Electro-Nucleonics, Inc., Fairfield, N.J.) or Silica, termed Nu-Gel, may be used as this lower stationary phase. A suitable volume of this segment 18a is 0.1 ml. The characteristics are as follows: Nu-Gel 952 AC 200 angstrom pore size, 200-400 mesh.
The hydrophobic upper phase segment 18b is formed of reverse phase HPLC material such as alkyl (C8 to C18) coupled silica. This material has good flow characteristics and is resistant to reagents used in sequencing. A suitable volume of this segment 18b is 0.1 ml. The characteristics of Synchroprep coupled silica are as follows: 300 angstrom pore size, 30 micron particle size.
While the double stationary phase system is preferable because of its ability to retain the peptides as described below, it should be understood that a single phase, preferably of the hydrophilic type may also be employed with bidirectional flow.
Overall, the importance of the chromatographic phase is that the peptide which is mobile, i.e., not covalently bonded to the chromatographic material but rather reversibly adsorbed, is retained by this system when passing upwardly in an aqueous solution because of the use of the reverse phase material. The normal phase lower column retains the peptide when conducting organic solvent downward for extraction of excess reagent, byproducts and the amino acid (ATZ) derivative.
The chromatographic medium is preferably a particulate bed retained in place during liquid flow by a suitable material at its top and bottom ends which permits passage of fluid but not of the particulate chromatographic bed. As illustrated, such retention means comprise porous plugs 17 suitably formed of glass or Teflon wool.
Referring again to FIG. 1, line 12 is removably sealed to port 16. Chamber 14 is provided with a second port 20 at its upper end which communicates with line 22. The system is fluid tight at ports 16 and 20. Appropriate releasable fittings or couplings (81) are provided at both ends for ready engagement and disengagement with the sequencer to form a fluid-tight seal at ports 16 and 20 in a conventional manner. In this way, after completion of the sequence, chamber 14 becomes a cartridge which may be removed from the sequencer and preferably replaced with a clean cartridge for each run to avoid cross contamination of peptides.
A suitable sample chamber is a small glass column, (2mm in diameter) which may be equipped with suitable means for temperature control such as a water jacket 80 through which temperature adjusted fluid is passed via conduits 82. The column fitting at the lower end 81 may be formed by melting the column to restriction into which a piece of small bore [1.5 mm] Teflon tubing is wedged to a tight fit (see FIG. 3). The tubing may then be held tight by spring tension or an O-ring and screw fitting.
The system includes first reservoir means or block (including reagent, coupling reagent and coupling base containers). generally designated by the number 28. Flow from block 28 proceeds through line 30 to four way valve 32. As illustrated, block 28 includes a source 34 of pressurized inert gas (e g., nitrogen), a solvent container 36, a vapor buffer (coupling base) container 38, a liquid buffer (coupling base) container 40 and coupling reagent (PITC) container 42. The terms "buffer" and "coupling base" are used interchangeably.
The system also includes a cleavage reagent block 44 connected by line 46 to valve 32. Block 44 includes a source 48 of inert gas, a solvent container 52, a container 54 of cleavage reagent (TFA) vapor and a container 56 of liquid cleavage reagent (TFA). Valve 32 is connected by line 58 to a second four-way valve 60 including one position to waste line 62 and another position for passing derivatized amino acid into line 64 communicating with a suitable detector 84. Line 12 interconnects sample chamber 14 and valve 60.
Line 22 is connected to four-way valve 66 which is in turn connected by lines 68 to a series of containers in a solvent block, designated by the number 70. Block 70 includes in sequence a source 72 of inert gas, valved container 74 for acetonitrile solvent, valved container 76 for ethyl acetate solvent, and valved container 78 for benzene solvent. A high pressure valve (not shown) may be interposed in line 68 between the solvent reservoirs and the valve 66.
For convenience of description, the sample chamber will be described in a vertical orientation with port 16 designated the bottom and port 20 designated the top. However, it should be understood that orientation of the sample chamber does not affect the procedure. For example, it may be inverted or disposed horizontally. In the present description, the bottom will refer to the inlet adjacent to the normal or hydrophilic chromatographic medium (the "lower medium") while the top designation will refer to the port adjacent to the reverse phase or hydrophobic chromatographic medium (the "upper medium").
Methodology
In step 1 (FIG. 2a), a sample 202 in injection valve 10, suitably in an aqueous solution, is loaded from the bottom of the column by injecting sample 202, including 204, 206 and 208 through line 12a and line 12 into chamber 14. Most proteins and some peptides 206 will be retained by the hydrophilic lower medium segment 18a. Proteins and hydrophobic peptides 208 can be supplied in solutions with high concentration of salts and other denaturants (e.g., urea, SDS, sucrose and the like). If the protein is in a high concentration of salt or denaturant, it may elute from lower medium segment 18a and migrate up into segment 18b, where it is retained as illustrated by released protein 208 in FIG. 2a. The solution that passes through the column may be collected for analysis to verify that all of the protein is retained by the column. In this instance, valve 60 is in a bypass position while valve 66 is in the illustrated position with excess solution being collected at line 88. Solvents from block 70 are vented to waste through line 83.
Typically, medium 18 is flooded with aqueous sample solution so that the protein in the solution migrates upwardly through the column but is retarded by the hydrophobic upper medium segment 18b. It is noted that although it is preferable to load the peptide from the bottom of the system, it may also be loaded from the top.
Step 2
In this step, wash solution injected at injection valve 10, previously used for the sample, flows upwardly through the column and line 80 for removal to a wash collection vessel. The wash solution may be water or a low concentration of acetonitrile as a mobile phase which preferably flows from the bottom to the top of the column and out the top. In this step, the remaining salts denaturants or small unwanted peptides or amino acids are removed from the sample chamber. Steps 1 and/or 2 may be performed automatically or manually and chamber 14 may be disconnected and stored for subsequent sequencing. In an alternative embodiment the aqueous sample and wash solutions may be introduced into chamber 14 while chamber 14 is disconnected from the sequencer, with subsequent attachment to the sequencer.
Step 3
In this step, suitable coupling reagent (PITC) is delivered in a suitable solvent (e.g., acetonitrile or heptane), preferably 2% PITC in heptane and the reactants are maintained at about 55° C. in the column. See FIG. 2b. In one embodiment, the a coupling base [buffer] 40a 42 first is directed through valves 32 and 60, then through line 62 to waste, thereby filling the dead volume between the two valves (58). Thereafter, the positions of valves 32 and 60 are changed simultaneously and inert gas in source 48 of block 44 is directed to pass the precisely controlled amount of coupling reagent in the dead volume loop 58 between valves 32 and 60 into the bottom of reaction column 14. This embodiment using carefully controlled volume is optional but preferred. Once the coupling reagent is passing into the column, the unused portion of the reagent in valve 32 may be washed out by passing inert gas from source 34 through line 30 and valve 32 to waste as designated by line 82.
In an alternative mode, step 3 may be performed by delivering the coupling reagent from container 42 directly through valves 32 and 60 to the bottom of the reaction column simply by opening the coupling reagent 12a control valve (not shown) with valves 32 and 60 connected to the reaction column. This technique is less preferred because the volume of coupling reagent which passes through the sample chamber is not controlled as precisely as the above referred mode using a precise loop volume. This mode can be used in the usual case where the peptide is retained by the hydrophobic segment 18b. In this alternative mode, it is preferable to carry the PITC in heptane rather than acetonitrile to avoid elution of small peptides from the top of the hydrophilic medium section if a large amount of coupling reagent were inadvertently used.
After either of the above two procedures of delivering coupling reagent, it is preferable to dry the system by flow of inert gas either from the top or bottom of the sample chamber from sources 34, 48 or 72. This drying serves the function of removing the solvent. However, it is an optional step.
Step 4
In this step, a coupling base (buffer) 40a (FIG. 2b) is delivered in an analogous manner to that of step 3.
The loop method described first above can be used to deliver a small precisely controlled amount of liquid buffer to protect against successive amounts being delivered which may carry small peptides up the column. The liquid buffer may be combined with volatile buffer (e.g., trimethylamine or triethylamine and water) from source 28. Since the amount of liquid delivered in this manner will typically be too small to entirely wet the chromatographic medium, the peptide will migrate upwardly through the column but not out of the sample chamber. If the peptide is so large as to be retained on the hydrophobic medium, an amount of liquid buffer 40a may be used that exceeds the column volume. This takes advantage of the two phase discontinuous hydrophilic-hydrophobic system to focus the large peptide at the interface between the normal phase support and the upper reverse phase support.
The volume of liquid buffer delivered is increased beyond the column volume by first opening the liquid buffer valve for container 40 in block 28 so that the liquid flows through valves 32 and 60 and to waste via line 62. Then, valve 60 is shifted in position to direct the liquid buffer upwardly through line 12 to the column shortly (e.g.. two seconds) before valve 32 diverts flow to waste via line 82. Inert gas from source 48 in block 44 is used to force the buffer through valve 60 and line 12 into the bottom of the reaction column 14. This timing can be adjusted so that sufficient liquid buffer enters the sample chamber to wet the entire chromatographic medium 18 with excess buffer free to be eluted through the top of the column. The following criteria are used to select the coupling base. The coupling base will control the pH to within the range from 8-10 and will dissolve both peptide and coupling reagent Suitable coupling bases include hydrophilic solutions such as Quadrol, DMAA, DMBA, or the like, but preferably supplied with a propanol content lower than that present in conventional sources of these products (e.g., 5-20% or less). Such a hydrophilic solution typically causes moderate migration of the peptides upwardly through the hydrophilic chromatographic medium but very slow migration at best through the hydrophilic medium segment.
The flexibility of this system to permit use of such high volumes of liquid buffer 40a permits an increase in efficiency of the coupling reaction by precise pH control. If desired, the liquid buffer can also contain detergents such as SDS to help solubilize the protein. Another reagent that may be included is Norleucine, a primary amine similar to natural amino acids, which may be used as an internal standard and carrier-scavenger for PTC amino acid.
Although Steps 3 and 4 are described in terms of sequential addition of coupling reagent and coupling base, it is only important to the reaction that the two reagents be in simultaneous contact with the peptide as shown in FIG. 2b. Thus, the system can be operated by combining steps 3 and 4 with the combined addition of coupling reagent and coupling base.
Step 5
In this step, the column is dried by flow of inert gas after completion of the coupling reaction. In a preferred technique, the gas first is directed upwardly so that aqueous liquid flows in the direction of hydrophobic material. This may be accomplished by passing inert gas from source 34 through valves 32 and 60 and line 12 upwardly through the column. Then, after most of the liquid is removed, the drying may be completed by high pressure gas such as supplied by inert gas source 72 through a high pressure valve in line. 68. The gas then flows through valve 66 and line 22, column 14 line 12, valve 60, line 62 and out to waste. Complete removal of water is desirable but is not as critical as in prior techniques such as a spinning cup sequencer or gas sequencer described above. This is because migration of the peptide due to the water which causes the organic mobile phase to become more hydrophilic would be counterbalanced by the next addition of liquid buffer from the bottom which causes refocusing of the peptide back towards the interface between the hydrophilic and hydrophobic material.
During downward movement of the high pressure gas, valve 32 may be washed by the passage of solvent from container 36 through the valve and to waste along line 82.
Step 6
In this step (FIG. 2c), organic solvents 70a are passed through the sample chamber in a downward direction to remove non-volatile side products and remaining buffers from the column. The solvents used for elution range from very non-polar solvents such as heptane and benzene to solvents of more moderate polarity such as ethyl acetate or acetonitrile. All solvents enter from the top of the column and are eluted down and out of the bottom of the column. Typically, the solvents delivered in line 68 through valve 66 and line 22 have a pressure on the order of about 10 psi to 100 psi. Valves in the containers in block 70 must be able to withstand pressure of up to 100 psi from source 72 so that high pressure inert gas is flowed through the column to compress any gas bubbles that may trap remaining side products or reagents.
Step 7
In this step, a coupled (PTC) peptide 232, as shown in FIG. 2c is cleaved with a cleavage acid (FIG. 2d). The temperature for acid extraction is about 0° C. to 50° C. The following criterion is used to select the appropriate cleavage acid 246: It must be anhydrous and volatile and of low enough pH to cause cleavage of the PTC peptide into the thiazolinone (ATZ) amino acid 242 and a free peptide 244 of one less amino acid. Cleavage may be performed with either a liquid acid (HFBA, TFA, PFPA, or the like in an anhydrous solution of acetic acid or acetonitrile, or the like), an acid vapor or a combination of both. The liquid acid increases the kinetics of the reaction. On the other hand, use of the gas reduces the risk of elution of the peptide off the top of the column. Thus, the liquid acid is preferred for shortened reaction times where the peptide is relatively large and so the risk of elution from the column is not great. The system may operate with liquid acid at the beginning stages of sequencing and with a gas phase acid at the later stages when the peptide chain is reduced substantially.
Referring to the use of acid vapor cleavage, vapor from container 54 is directed through line 46 and valves 32 and 60 through line 12 into the bottom of sample chamber 14. The same flow system is used for delivery of the liquid cleavage acid from source 56.
It is preferable to perform the cleavage reaction at a temperature of 10° C. to 50° C. The temperature may be varied by the temperature of the circulating water in the water jacket 80. The reaction is stopped by drying of excess liquid or gaseous acid by an upward flow of inert gas followed by high pressure downward flow as described above Drying may be more complete than in either the gas phase sequencer or spinning cup sequencer. This is because the extraction of the cleaved ATZ amino acid may be performed with a more polar solvent than in these two systems because of the chromatographic separation of ATZ amino acid from the remaining peptide. The extraction does not depend on a small amount of remaining acid as in these prior art techniques.
Step 8
In this final stage (FIG. 2e), the cleaved ATZ amino acid 242 is extracted with a suitable organic extraction solvent 70b such as ethylacetate or acetonitrile. Criteria for selecting the solvent are as follows: Complete elution of all ATZ amino acids but some migration of free peptide through the resin.
As illustrated, solvent 70b from container 76 is passed through valve 66 and through line 22 downwardly through the column through valve 60 and line 64 and to a suitable reaction vial 84a for subsequent reaction. The cleaved ATZ amino acid 242 in solvent is converted in such a vial, not shown, to stable PTH amino acids in a conventional manner. As is typical, the vial can contain or have added to it an aqueous solution of TFA for the aqueous acid conversion. An inert gas is flowed through the sample chamber in a manner described above to remove remaining organic acid. Then the column is ready for the sequencing procedure to be repeated for subsequent ATZ amino acid derivatives.
After conversion of the ATZ-amino acids 242 to PTH-amino acids by reaction with the acid (not shown), the residues can be identified by suitable liquid phase chromatography.
One advantage of the above system is that the sample chamber can be bypassed so that the reagent delivery system can be washed directly to waste. Furthermore, in the case of a microsequencer, the volume of the valve and lines needed to deliver all reagents used in Edman degradation chemistry can be as large as the column volume. Bypassing the sample chamber eliminates the problem of washing excess reagents remaining in the valves and lines to waste via the sample-containing sample chamber. This reduces the amount of solvent flowing over the sample. Excess washing by solvent is detrimental due to extractive losses of sample as well as oxidation of the PTC-peptide by trace amounts of peroxide in solvent. The valve in-line washing process can proceed while the sample chamber is being dried which helps reduce the time of the wash.
A major advantage of this system is the ability to use a mobile phase of the peptide without covalent attachment to the medium but without washout of the sample. The liquid reagents are chosen to dissolve the peptide to cause migration in the direction of flow. By alternating flow directions, the peptide moves up and down the column and tends to focus at the interface between the hydrophilic and hydrophobic phase. The rate of migration will depend upon the partitioning between the mobile phase (liquid reagent) and stationary phase (chromatographic medium).
To illustrate focusing of the peptide in the column, a sample of peptide in an aqueous solution loaded into the sample chamber, flows upwardly through the column. Some peptide typically is contained in the hydrophilic lower segment while other peptides are retained by the hydrophobic upper segment. Low molecular weight components are eluted off the column. During the coupling step the aqueous coupling base and the coupling reagent pass upwardly trough the column and the peptide tends to move upwardly into the hydrophobic medium. Thereafter, in step 6, the organic solvents pass downwardly through the column to again move the PTC amino acid towards the hydrophilic phase. Then, in step 7, the cleavage acid again passes upwardly into the column to move the peptide towards the hydrophobic section. Finally, the extraction of the ATZ amino acid derivative is performed in a downward direction. This bidirectional movement of the peptide by varying the direction of flow between the hydrophilic and hydrophobic chromatographic sections causes a focusing of the peptide near the interface between the two segments to prevent washout of the peptide during the procedure.
The references grouped in the following bibliography and respectively cited parenthetically by number in the foregoing text, are hereby incorporated by reference.
Bibliography
1. S. Datta, et al., Biochem. and Biophys. Res. Commun., 72 (1976) 1296-1303.
2. R. A. Laursen, J. Am. Chem Soc., 88 (1966) 5344-5346.
3. P. Edman. "Protein Sequence Determinations," S. B. Needleman, ed., Springer-Verlage, New York (1975) 237.
4. H. D. Niall, "Automated Edman Degradation: The Protein Sequencer," Methods Enzymol., XXVII (D) (1974) 942.
5. G. E. Tarr, Anal. Biochem., 63 (1975) 361-370.
6. H. Fraenkel.Conrat, J. Am. Chem. Soc., 76 (1954) 3606.
7. P. Edman. et al. Eur. J. Biochem., 1 (1967) 80-91.
8. H. Fraenkel-Conrat, et al. "Recent Developments in Techniques for Terminal and Sequence Studies in Peptides and Proteins," Methods of Biochem: Anal., Vol. 2, D. Glick, ed., Interscience, New York (1955) 359-425.
9. M. A. Hermodson, et al. Biochemistry, 11 (1972) 4493-4502.
10. R. A. Laursen, et al. FEBS Lett., 21 (1972) 67-70.
11. J. D. Lynn, et al Anal. Biochem., 45 (1972) 498-509.
12. K. Titani, et al. Nature (New Biol.), 238 (1972) 35-37.
13. E. Wachter, et al. FEBS Lett., 35 (1973) 97-102.
14. M. D. Waterfield, et al. Anal. Biochem. 38 (1970) 475-492.
15. M. J. Horn, et al. FEBS Lett. 36 (1973) 285-288.
16. A. Previero, et al. FEBS Lett , 33 (1973) 135-138.
17. R. A. Laursen, Eur. J. Biochem., 20 (1971) 89-102.
18. R. A. Laursen, "Solid Phase Methods in Protein Sequence Analysis," Pierce Chemical Company, 1975.
19. J. E. Strickler, et al. Anal. Biochem., 140 (1984) 553-566. | A device for the determination of amino acid sequence of a polypeptide comprises two new features offering great advantages in the cost and efficiency of operation of amino acid sequencers. The sequencer is provided with the capability for the bidirectional flow of sequencing reagents and contains a sample chamber having a bicompositional adsorbent for the polypeptide. | 8 |
PRIORITY CLAIM
The present application claims priority from PCT/EP2010/055213, filed 20 Apr. 2010, which claims priority from European Application 09158479.7, filed 22 Apr. 2009.
BACKGROUND
The invention is directed to a process for the preparation of hydrogen and carbon monoxide containing gas from a gaseous carbonaceous feedstock. The process involves the combination of an auto-thermal reforming process and a heat exchange catalytic steam reforming process.
Such a process is described in U.S. Pat. No. 7,087,652. This process involves steam reforming of natural gas in a multi-tubular heat exchange reformer to obtain a reformed gas. This reformed gas is subsequently fed to an auto-thermal reformer (ATR) to obtain an auto-thermal reformer effluent. This effluent is used as the hot gas to provide heat in the heat exchange reformer. The heat exchange reformer is a shell and tube vessel, wherein the reforming catalyst is present in the tubes and where the hot effluent of the ATR flows at the shell side.
U.S. Pat. No. 6,224,789 describes a process involving steam reforming of natural gas in a multi-tubular heat exchange reformer to obtain a reformed gas. In parallel another part of the natural gas is fed to an auto-thermal reformer (ATR) to obtain an auto-thermal reformer effluent. This effluent is used as the hot gas to provide heat in the heat exchange reformer. The reformed gas and the effluent of the ATR after being used as hot gas is combined to obtain a hydrogen and carbon monoxide containing gas as the product of this process.
In both prior art processes the heat exchange reformer is typically a large multi-tubular reactor with several hundred catalyst tubes in a vessel which is 20-30 m high by 4-7 m diameter. Such a unit comprises several tubesheets, refractory lining, heat exchange enhancements such as baffles and sheath-tubes on the shell-side, making the unit difficult to manufacture.
Mixtures of hydrogen and carbon monoxide, sometimes referred to as synthesis gas or syngas, are used as feedstock to a variety of processes to make chemicals, oil products and/or power. When the mixture is used as feed to a Fischer-Tropsch process or to a methanol synthesis process it is sometimes desirable to use a mixture having a hydrogen to carbon monoxide molar ratio of around 2. When preparing such a mixture in the above processes it is found that one will preferably operate at low steam to carbon ratio's. Operation at such conditions in turn results in the synthesis gas mixture as prepared being in the metal dusting corrosion region and as such being very aggressive towards low alloy steel grades. Because of this metal-dusting corrosion special high alloy steel grades resistant to metal dusting will have to be used for the heat exchange surfaces of the heat exchange reformer. Such steel grades are very expensive and add to the cost of the unit.
It is known that the allowable pressure differential at the high temperatures of the above processes for such high alloy steel grades is limited. As a result special instrument protective systems have to be installed to avoid such pressure differentials when the process is in operation. This adds to the complexity of the process.
SUMMARY OF INVENTION
The aim of the present invention is to provide a process, which overcomes the above problems.
This is achieved with the following process. Process for the preparation of hydrogen and carbon monoxide containing gas from a gaseous carbonaceous feedstock by performing the following steps:
(a) auto-thermal reforming of a gaseous feedstock thereby obtaining a first gaseous mixture of hydrogen and carbon monoxide, (b) catalytic steam reforming of the gaseous carbonaceous feedstock to obtain a second gaseous mixture of hydrogen and carbon monoxide by feeding steam and the gaseous carbonaceous feedstock through a first set of numerous microchannels provided with a catalytic steam reforming function and feeding the first gaseous mixture of hydrogen and carbon monoxide through a second set of numerous microchannels, wherein the first and second set of microchannels are oriented such that the required heat for the steam reforming reaction in the first set of microchannels is provided by convective heat exchange from the second set of microchannels, thereby obtaining the hydrogen and carbon monoxide containing gas as the effluent of the second set of microchannels.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a preferred configuration for the first and second set of microchannels.
FIG. 2 illustrates a stacked plate heat exchange reformer.
FIGS. 3 and 3 a illustrate a pressure vessel containing more than one heat exchange reformer.
FIG. 4 shows how a combined heat exchange reformer is used in a process line-up according to the invention.
DETAILED DESCRIPTION
Applicants found that the heat exchange catalytic steam reforming can be performed in more simple equipment, which mitigates several of the disadvantages of the heat exchange reformer reactor of the prior art. The allowable pressure differential in microchannel reactor is higher than in the prior art reactor design. Furthermore due to the enhanced heat transfer performance of the microchannel reactor the required heat transfer area can be much less. This may result in a reduction in the content of high alloy steel in the reactor of 60% as compared to the prior art reactors. This is advantageous in reducing cost and reactor size because such high alloy steel is expensive and difficult to obtain. Further advantages are the smaller plot size required for the process according to the invention. Further advantages will be described when discussing the below preferred embodiments.
The gaseous carbonaceous feedstock used in step (b) is preferably a methane comprising gas. The methane comprising gas can be obtained from various sources such as natural gas, refinery gas, associated gas or coal bed methane and the like. The gaseous carbonaceous feedstock suitably comprises mainly, i.e. more than 90 v/v %, especially more than 94%, C 1-4 hydrocarbons, especially comprises at least 60 v/v percent methane, preferably at least 75 volume percent, more preferably at least 90 volume percent. Preferably natural gas or associated gas is used as the gaseous carbonaceous feedstock.
In a preferred embodiment the gaseous feedstock in step (a) is a methane comprising gas. More preferably it is the same methane comprising gas as used as the gaseous carbonaceous feedstock in step (b). In such an embodiment it is furthermore preferred to feed a combination of the first and second gaseous mixtures of hydrogen and carbon monoxide through the second set of numerous microchannels. Such a configuration is also referred to as a parallel process configuration.
More preferably the process is performed in a series configuration wherein all or part of the second gaseous mixture of hydrogen and carbon monoxide is used as the gaseous feedstock of step (a). Because the steam reforming equilibrium temperature achieved in step (a) is higher, for example between 1000 and 1100° C., compared to step (b), for example between 800 and 900° C., a higher conversion of methane is achieved in a series configuration. This results in a more efficient process. In such a series configuration the gaseous feedstock in step (a) may suitably comprise all or part of the second gaseous mixture of hydrogen and carbon monoxide and another part of the gaseous carbonaceous feedstock.
In any of the embodiments described above it has been found that the temperature of the gas as it enters the second set of microchannels is advantageously between 800 and 1100° C. Higher temperatures are presently not possible due to the limitations of the materials of construction.
For some applications, like for example a cobalt catalysed Fischer-Tropsch process as performed in a fixed bed reactor, it is found advantageous to use a mixture of carbon monoxide and hydrogen having a H 2 over CO molar ratio of between 1.5 and 2.1. Such a desired molar ratio can be achieved with the process according to the invention by feeding a carbon dioxide rich gas to step (a) at such a rate that the content of carbon dioxide, on a dry basis, in the total feed to step (a) is between 1 and 10 vol. %. Such a CO 2 rich gas may suitably the off-gas as produced as by-product in the Fischer-Tropsch synthesis itself.
Step (a) is an auto-thermal reformer, which technology is well known to the skilled person.
In step (b) the gaseous carbonaceous feedstock is converted to the second gaseous mixture of hydrogen and carbon monoxide by means of a steam reforming reaction, which takes place in the presence of a reforming catalyst as present in the first set of numerous microchannels. Steam reforming itself is well known and will not be dealt with in great detail. Preferably the steam to carbon molar ratio of the feed to the first set of numerous microchannels in step (b) is between 0.5 and 3.0.
The first gaseous mixture is fed through the second set of microchannels. Because the first gaseous mixture has a relatively high temperature heat is transferred to the first set of microchannels to perform the endothermic reforming reaction.
In order to achieve the most optimal heat exchange the first and second set of microchannels are preferably arranged alternately to ensure good thermal contact between the channels. Channels in individual steel plates suitably form the microchannels. The steel plates are preferably stacked and diffusion bonded together. Preferably the microchannels of the first and second set are positioned such that the flow direction in the first set of microchannels is substantially counter-current with the flow direction in the second set of microchannels.
The number of microchannels in such plate may vary from more than 10 to more than 10000. The microchannel in such a plate preferably has a height of 5 mm or less, more preferably 2 mm or less, and still more preferably 1 mm or less, and in some preferred embodiments height is in the range of 0.1 and 2 mm. Channel cross-sections can be, for example, rectangular, circular, triangular, or irregularly shaped. Height and width are perpendicular to length and either or both can vary along the length of a microchannel. Height and width can be arbitrarily selected; in the present invention, height is defined as the smallest dimension of a channel that is perpendicular to flow.
The thickness of a steel plate is preferably such that the sufficient heat transfer is possible, while at the same time sufficient mechanical strength is provided. The thickness will thus depend on the type of material chosen for the plate and the dimensions of the microchannel. Suitably the thickness is between 0.2 and 4 mm.
The steel plates, and preferably the steel plates which come into contact with the first gaseous mixture, are preferably made of a metal alloy, which can withstand metal dusting. Such high alloy steel will preferably comprises between 0 and 20 wt % iron, between 0 and 5 wt % aluminium, between 0 and 5 wt % silicon, between 20 and 50 wt % chromium and at least 35 wt % nickel. More preferably the content of chromium in the metal alloy is more than 30 wt %. More preferably the metal alloy comprises between 1 and 5 wt % aluminium. More preferably the metal alloy comprises between 1 and 5 wt % silicon. More preferably the metal alloy comprises between 0 and 2 wt % titanium and/or REM.
The first set of microchannels will comprise a reforming catalytic function. This may be a typical reforming catalyst known to the skilled person. The method of loading the catalyst in said microchannels is described in for example WO-A-2004037418. A suitable method is to wash coat a steam reforming catalyst on a to the inner surfaces of the microchannels.
A preferred configuration for the first and second set of microchannels is described in FIG. 1 . FIG. 1 shows plate 1 and numerous microchannels 2 forming the first set of numerous microchannels provided with a steam reforming catalyst 3 . Microchannels 2 have an inlet end 4 for the gaseous carbonaceous feedstock and an outlet end 5 for the second gaseous mixture of hydrogen and carbon monoxide. FIG. 1 also shows plate 6 and numerous microchannels 7 forming the second set of numerous microchannels. Microchannels 7 are provided with inlet openings 11 fluidly connected to a common header channel 8 through which the first gaseous mixture is supplied to the numerous microchannels 7 . At the downstream end 9 b of the microchannels 7 the cooled gas is collected in a common header 9 .
FIG. 2 illustrates a stack of plates 1 and 6 arranged alternately to form the heat exchange reformer 10 which may be advantageously used in the process according to the invention. The number of plates 1 and 6 will typically be greater than shown. FIG. 2 also shows header 8 , header 9 , header 5 a and header 4 b . These headers are welded around the inlet and outflow openings as present in plates 1 and 6 . Header 8 is fluidly connected to inlet 11 a . Header 9 is fluidly connected to outlet 9 a . Header 4 b is fluidly connected to inlet 4 a and header 5 a is fluidly connected to outlet 12 a.
FIG. 3 shows an embodiment wherein more than one heat exchange reformer 10 is positioned in a single pressure vessel 13 to form a combined heat exchange reformer 14 . Only the inlets 4 a , 11 a and outlets 9 a and 12 a for the various streams pass the pressure vessel wall making the design of the combined heat exchange reformer 14 more simple. Alternatively header 4 b and inlet 4 a may be omitted to obtain reformer 10 ′ modules and combined heat exchange reformer 14 ′ as shown in FIG. 3 a . The gaseous carbonaceous feedstock and steam, being the coldest gas stream, will then be provided by a single inlet 18 directly into the interior of the pressure vessel 19 or 14 ′. The inner wall of vessel 19 is preferably refractory lined.
FIG. 4 shows how combined heat exchange reformer of FIG. 3 or 3 a is used in a process line-up according to the present invention. To combined heat exchange reformer 14 a mixture of steam and a methane comprising gas is fed via inlet 4 a . The resulting second gaseous mixture of hydrogen and carbon monoxide is fed via 12 a to auto-thermal reformer 15 . To said auto-thermal reformer 15 also oxygen, via 16 , and a CO 2 comprising gas and a gaseous carbonaceous feedstock such as methane are fed, via 17 . The resulting first gaseous mixture of hydrogen and carbon monoxide is fed via 11 a to combined heat exchange reformer 14 . The product of the process, namely the hydrogen and carbon monoxide containing gas as discharged from the second set of microchannels, is discharged from the reformer 14 via 9 a. | Process for the preparation of hydrogen and carbon monoxide containing gas from a gaseous carbonaceous feedstock by performing the following steps: (a) auto-thermal reforming of a gaseous feedstock thereby obtaining a first gaseous mixture of hydrogen and carbon monoxide, (b) catalytic steam reforming of the gaseous carbonaceous feedstock to obtain a second gaseous mixture of hydrogen and carbon monoxide by feeding steam and the gaseous carbonaceous feedstock through a first set of numerous microchannels provided with a steam reforming catalyst and feeding the first gaseous mixture of hydrogen and carbon monoxide through a second set of numerous microchannels, wherein the first and second set of microchannels are oriented such that the required heat for the steam reforming reaction in the first set of microchannels is provided by convective heat exchange from the second set of microchannels, thereby obtaining the hydrogen and carbon monoxide containing gas as the effluent of the second set of microchannels. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a cylindrical, axially compressible cheese center or centre for dyeing a package of yarn or textile thread wound on the center, and more particularly to such a cheese center having two end rings between which are arranged several stiffening rings in axial succession, each of which stiffening rings is firmly connected to an adjacent stiffening ring and to an end ring or to another adjacent stiffening ring by means of a plurality of springy webs. The cheese center has ring connecting webs which are bent at right angles and joined to the rings at right angles, the external surfaces of all the webs and of the stiffening rings and of the sections by which the webs being connected to the end rings forming a cylindrical envelope.
2. Description of the Prior Art
In a cheese centre of this type disclosed in DE-A-2 062 520/U.S. Pat. No. 3 753 534, in which the stiffening rings are identical and equidistant and the webs between two adjacent rings are identically formed but the webs in one row of webs between two adjacent rings are the mirror images of the webs in the adjacent row, there are no spacer lugs of the type disclosed, for example, in DE-U-7 516 449 (FIGS. 5 and 6) between two adjacent rings. The said spacer lugs disclosed in the said DE-U 7 516 449 are designed to cooperate in pairs to prevent the stiffening rings, which are connected by S-shaped webs, from approaching each other so closely, when the cheese centre is compressed in the axial direction, that the radial openings in the cheese centre will virtually close up and thus prevent the passage of dyeing liquid. Consequently, as these pairs of spacers are absent from the known cheese centre mentioned above, axial compression of the centre is liable to cause fibres of the wound yarn or the wound textile thread to get clamped between the ring connecting web and a stiffening or end ring and thereby be damaged.
SUMMARY AND OBJECTS OF THE INVENTION
It is therefore an object of the present invention to provide a compressible cheese centre for dyeing purposes in which this disadvantage is avoided and which protects the material wound on to the centre for dyeing purposes when the centre is under axial compression.
In a cheese centre of the type defined above, this problem is solved according to the invention by the provision of a plurality of pairs of cooperating spacer lugs formed on the rings (stiffening rings and end rings), each of these pairs of spacers being arranged between two ring connecting webs which are adjacent to one another in the circumferential direction, and between two adjacent rings so that the two spacers of each pair meet each other in the axial direction when the said adjacent rings approach one another.
In the cheese centre disclosed in DE-U-7 516 449 (FIGS. 5 and 6), similar spacers are provided between the rings but the two spacers of each pair are arranged in axial alignment in front of and behind a ring connecting web so that the two spacers of a pair strike with their entire contact surfaces, which are parallel to one another and set obliquely to the longitudinal axis of the cheese centre, against the non-axially extending middle section (main section) of the associated connecting web, one from each side of the web on axially opposite sides thereof. This action of the spacers against the ring connecting webs is said to stabilize the webs when the cheese centre is in the compressed state.
The cheese centre according to the present invention, on the other hand, has the advantage of safely preventing any part of a ring connecting web from making contact with the adjacent stiffening ring in the event of excessive axial compression of the cheese centre. Such contact could not only cause clamping of the fibres but could also lead to breakage of the ring connecting webs, especially if they are of the known type of hook-shaped webs.
In a preferred embodiment of the cheese centre according to the invention there is a clear radial distance between the spacer lugs and the envelope so that there will be no risk of fibres getting clamped between two lugs in contact with one another.
Also in the preferred embodiment, the spacer lugs of each pair are staggered in relation to one another in the circumferential direction by such an amount that when the cheese centre is under torsion due to compression, the lugs will make contact with one another in a direction parallel to the axis. This arrangement of the lugs of a pair, which are not spread out in the circumferential direction, obviates the spreading out of the lugs which would be necessary to ensure that the lugs meet and support one another if they were situated axially opposite one another and which would have the undesirable effect of reducing the size of the opening in the cheese centre.
Further in the preferred embodiment, one of several identical groups, each consisting of at least two ring connecting webs, is arranged in the circumferential direction between every two adjacent pairs of spacer lugs, the said connecting webs having the same distance apart in all the groups. This not only ensures the periodicity of the elements of the cheese centre in the circumferential direction but also obviates the need to provide pairs of spacer lugs between every two ring connecting webs adjacent to one another in the circumferential direction.
Lastly, in the preferred embodiment, adjacent end sections of two ring connecting webs provided one on each side of the same stiffening ring are staggered in relation to one another in the circumferential direction. By contrast, this staggered arrangement is not provided in the two known types of cheese centres and consequently the axial rigidity of the cheese centres is not uniformly distributed over the circumference of these known centres.
In the preferred embodiment of the cheese centre according to the invention with hook shaped ring connecting webs, the cross-sections of these identical webs taken transversely to their longitudinal direction are rectangular surfaces of equal area which have a greater dimension in the radial direction than in the direction parallel to the axis and in the circumferential direction. This known arrangement of the rectangular cross-sectional areas provides particularly great strength of the cheese centre in the radial direction, which is highly desirable on account of the centripetal internal pressure exerted on the cheese centre by the package wound on it.
In the preferred embodiment, the end sections of the hook shaped ring connecting webs, which end sections extend parallel to the axis, are approximately equal in length to the middle section of the webs. With this form of web, which in the extreme case results in the web being enclosed in a square such that the end sections of the web lie on two parallel sides of the square while the middle section of the web lies on the midline of the square, the strength of the cheese centre in the axial direction and the distance between the stiffening rings are both at an optimum, provided a sufficient number of ring connecting webs are situated between the adjacent stiffening rings of each section of the cheese centre, as is the case in the constructional example of the invention described below.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described in detail with reference to the preferred embodiment of the compressible cheese centre according to the invention illustrated by way of example in the drawing, in which
FIG. 1 is a perspective view of the embodiment with the webs and lugs omitted except in two subsections, in other words without any perforations shown in the central, main section,
FIG. 2 is a surface view of the plane development of a section of this embodiment of the cheese centre, and
FIG. 3 represents a section taken on the line III--III of FIG. 2 through a web and a lug of the embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In the preferred exemplary embodiment, the compressible cheese centre for dyeing purposes, which is fabricated of polypropylene, is substantially in the form of a circular cylindrical hollow body made in one piece comprising a long perforated middle section (10) and two relatively short end rings (12 and 14) which are complementary to one another in form so that two identical cheese centres can be plugged together in the axial direction.
The middle section (10) mainly comprises a plurality of identical stiffening rings (16) and a large number of ring connecting webs (18) which join two axially adjacent stiffening rings (16) together and each of which is connected at one end to a stiffening ring (16) and at its other end either to the adjacent stiffening ring (16) or to a web connecting section (20 or 22) of one of the end rings (12 and 14). The external surfaces of all the webs (18) and stiffening rings (16) and of the web connecting sections (20 and 22) of the end rings (12 and 14) form an external cylindrical envelope (24). Similarly, the internal surfaces of the above-mentioned parts of the cheese centre form a coaxial cylindrical envelope (26) in the interior of the cheese centre. The wall thickness of the middle section (10) is everywhere the same, i.e. the radial dimensions of the stiffening rings (16), the ring connecting webs (18) and the web connecting sections (20 and 22) of the end rings (12 and 14) are all the same. The axial width of the said stiffening rings (16) is, however, somewhat greater than the width of the ring connecting webs (18). This width of the connecting webs (18) is measured partly in the circumferential direction of the cheese centre and partly in its axial direction since the webs (18) are bent at right angles and connected to the rings (12,14 and 16) at right angles. The cross-sectional surface area of each web (18) is constant along the whole of its longitudinal line which is bent twice at an angle. The same applies to the stiffening rings (16), whose cross-sectional surfaces are rectangular in the planes of all the axial sections. The cross-sectional surfaces of the ring connecting webs (18) are also rectangular, both in all the radial sectional planes of the end sections (28) extending parallel to the axis and in all the axial sectional planes of the middle section (30) which extends in the circumferential direction and connects the two end sections. The middle section (30) of each web (18) is slightly longer than each of the two end sections (28) which are equal in length. When viewed in detail, each of these end sections (28) will be seen to be joined to the middle section (30) by way of an intermediate section (32) in the form of the quadrant of a circle in order to avoid indentation or the formation of a notch. The inner curvature (smaller radius of curvature) is also formed at the bases of the webs, where they join the rings (16 and 14 or 12). Several groups of ring connecting webs (18), each group composed of two webs (18) situated side by side in the circumferential direction, are arranged between every two adjacent rings (12,14 and 16). The two webs (18) of each group situated between the same two rings are arranged identically whereas the webs in each axially adjacent group are reversed so that the middle sections (30) in one group extend in the opposite circumferential direction to the middle sections of the webs in an axially adjacent group. Viewing the arrangements of connecting webs in the different sections of cheese centre extending from one stiffening ring (16) to the next or to an adjacent end ring (12 or 14), therefore, it will be seen that the arrangement alternates from one section to another in that, compared with the arrangement of the webs (18) in one section, the webs in the axially adjacent section are rotated about the longitudinal line of one of its two end sections (28) extending parallel to the axis.
The clear distance between two ring connecting webs (18) of the same group, which is approximately equal to the length of the middle sections(30) measured in the same circumferential direction, is smaller than the corresponding distance between one connecting web and the circumferentially adjacent web of the next group, so that the larger perforations in the cheese centre, which are situated between circumferentially adjacent webs belonging to different groups, are each large enough to accomodate a pair of cooperating spacer lugs (34). Each spacer lug (34) of a pair is joined to one of two axially adjacent rings (16, 14 or 12) in such a position that the two lugs of a pair are not in exact axial alignment although there is some overlap between them in the circumferential direction. The amount of shift between two spacer lugs (34) of a pair in the circumferential direction is calculated to ensure that the two lugs will correctly meet one another so that when pressure is applied to the cheese centre, the torsion produced between two successive stiffening rings (16) will not differ in amount but will change in sign from one section of the centre to the next.
The identical spacer lugs (34) are slightly wider than the ring connecting webs (18) in the circumferential direction but not as high as the webs in the radial direction, i.e. their radially inwardly facing broad side coincides with the internal envelope (26) but their radially outwardly facing side does not reach the outer envelope (24). While the two spacer lugs (34) of each pair in one and the same section of cheese centre are identically arranged, the arrangement alternates from one section of the cheese centre to the next so that the sign of the shift in position in the circumferential direction alternates.
The ring connecting webs (18) and the spacer lugs (34) are arranged to produce a periodicity in each section of the cheese centre so that identical pairs of webs and the pairs of lugs are uniformly distributed over the circumference of the centre and the arrangements recur in every second section. Whereas the number of webs and the number of lugs, which are the same in each section of the cheese centre and are inevitably equal to one another within a section, may be either even or odd, the number of sections should be even so that the total torsion of the compressed cheese centre between the two end rings (12 and 14) is theoretically zero.
In one end ring (12), the web connecting section (20), whose axial dimension is smaller than that of the stiffening rings (16), is followed by an end section (36) which forms the axially outer end of the cheese centre. The external surface of this end section (36), which is S-shaped or reverse S-shaped in profile, is situated radially more inwardly than the outer envelope (24), while its internal surface, which is in the form of a circular cylinder, forms part of the inner envelope (26). The other end ring (14), whose web connecting section (22) is wider in the axial direction than the stiffening rings (16), is accordingly followed by an outer end section (38) whose internal surface, which is correspondingly S-shaped or reverse S-shaped in profile, is radially external to the inner envelope (26), while its external surface, which is in the form of a circular cylinder, forms part of the outer envelope (24); and a groove forming a yarn or thread reserve (40) on the web connecting section (22) has its base on a smaller circumference than this outer envelope.
Several cheese centres described by way of example are fitted together in the axial direction so that they are locked together pairwise by their sections (36 and 38) in a form locking manner both in the axial and in the radial direction. When the packages mounted on the cheese centres are in the process of being dyed, a perforated spindle which has the external form of a circular cylinder equal in diameter to the internal envelope (26) of the cheese centres extends through the row of centres. When axial pressure is exerted on the free ends of the first and last cheese centre, all the cheese centres undergo axial compression so that the internal right angles of the ring connecting webs (18) are reduced and this compression may be continued until the paired spacer lugs (34) strike against one another. | A compressible cheese center for dyeing purposes, has two end rings, and a plurality of intermediate stiffening rings (12, 14 and 16) connected together by springy webs (18).
Spacer lugs (34) are arranged pairwise between webs (18) which are adjacent to one another in the circumferential direction of the cheese center so that the lugs (34) of each pair meet when they approach one another in the axial direction, preventing parts of the web from abutting against the adjacent ring when compression is too high. Such abutment could cause breakage of the web as well as clamping of the fibres or threads. | 3 |
FIELD OF THE INVENTION
[0001] The present invention relates broadly to glass panels which comprise spaced-apart edge sealed glass sheets. The present invention will be described herein with reference to vacuum glazing, however, it will be appreciated that the present invention does have broader applications including, for example, in automobile windows, glass panel displays or solar collector panels.
BACKGROUND OF THE INVENTION
[0002] Hermetic seals which are suitable for use in vacuum glazing typically involve the use of solder glass, which is also referred to as glass frit. The term “solder glass” refers to a glass which melts and softens at a lower temperature than the glass sheets of the glazing, but which has a coefficient of thermal expansion which closely matches that of the glass sheets. As such, a suitable solder glass will depend upon the glass used for the glass sheets of the vacuum glazing. A typical example of glass used for vacuum glazing is soda lime glass.
[0003] The use of solder glass has the advantage that, unlike other solders such as metal solder, it is “compatible” with the glass sheets. For example, bonds between the solder glass and the glass sheets can be formed by inter-diffusion. At the same time, the solder glass is impermeable so that a low pressure within the internal volume of vacuum glazing can be maintained indefinitely for all practical purposes.
[0004] To form an hermetic seal between two glass sheets of a vacuum glazing, solder glass, normally in the form of a viscous liquid paste containing solder glass powder, is provided around the edges of the glass sheets, which are positioned in a spaced apart relationship, e.g. by way of support pillars placed between the sheets. The entire structure is then heated to a temperature at which the solder glass melts and whilst in its molten state, flows by capillary action between the spaced apart sheets and diffuses into the atomic structure of the respective glass surfaces, forming a strong and leak free joint between them.
[0005] Although the temperature at which the edge seal process occurs is less than that at which the glass sheets soften and melt, it is in general necessary for the temperature at which the sealing process occurs to be such that the glass sheets are quite close to the point at which softening and distortion occur. In other words the influence of the heating on the glass sheets cannot be ignored for all purposes.
[0006] As an example, the temperatures necessary to form the seal with the process described above can result in a significant relaxation of internal stresses in the glass sheets. Treatment of the glass sheets at such temperatures for that purpose is commonly referred to as annealing. Although the annealing may result in the removal of unwanted stresses in the glass sheets for some applications, for other applications the removal of residual stresses during the formation of the solder glass seal is undesirable. As an example, it is often required that the glass in windows and doors should be tempered or heat strengthened. Tempered glass contains internal stresses which need to be retained to maintain the increased strength of the glass sheet.
[0007] Since a significant stress relaxation in the glass sheets cannot be avoided during the forming of the hermetic edge seal made from solder glass as described above, it has up until now been impossible to manufacture vacuum glazing which incorporates an hermetic edge seal made from solder glass and which utilize (fully) heat strengthened glass.
SUMMARY OF THE INVENTION
[0008] The present invention may be defined broadly as providing a method of constructing a glass panel which comprises two confronting edge sealed glass sheets. The method comprises the steps of providing a solder glass band around the margin of one surface of each glass sheet; forming, at a first temperature, an hermetic bond between the solder glass band and the associated surface of each glass sheet; positioning the glass sheets in spaced-apart confronting relationship; forming, at a second temperature which is lower than the first temperature, an hermetic seal between the two solder glass bands whilst maintaining the spaced apart relationship between the glass sheets, in a manner that substantially avoids annealing of either glass sheet.
[0009] In one embodiment, the step of forming the hermetic seal between the solder glass bands comprises fusing together the two solder glass bands to form an hermetic bond directly between those bands.
[0010] Alternatively, the step of forming the hermetic seal between the two solder glass bands comprises interposing solder glass between the two solder glass bands and fusing the solder glass with the two solder glass bands.
[0011] The temperature and time for forming the hermetic bond between the solder glass band and at least one of the glass sheets is preferably selected such that tempering of the glass sheet will be effected.
[0012] Support pillars may be used to maintain the glass sheets in the spaced apart relationship.
[0013] The method does have an application in vacuum glazing, in which case the method further comprises the step of evacuating the hermetically sealed space between the two glass sheets.
[0014] Preferably, the step of providing the marginal solder glass bands comprises depositing a liquid paste comprising solder glass powder onto the surfaces.
[0015] The solder glass may alternatively be deposited using different techniques, including deposition by a screen printing process or deposition as a pre-formed film or tape.
[0016] During the forming of the hermetic seal between the two solder glass bands, a spacing between the glass sheets may change compared to the situation when the glass sheets are positioned in the spaced-apart confronting relationship.
[0017] The glass sheets may be flat or curved and may be of any circumferential shape.
[0018] The present invention may also be defined in terms of a glass panel which comprises two confronting edge sealed glass sheets, in which the edge sealing is being effected by the above defined method.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Preferred forms of the invention will now be described, by way of example only, with reference to the accompanying drawings.
[0020] [0020]FIG. 1 is a schematic drawing illustrating a method of forming a glass panel embodying the present invention.
[0021] [0021]FIG. 2 is a schematic drawing illustrating another method of forming a glass panel embodying the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0022] We seek to manufacture a glass panel comprising two confronting edge sealed glass sheets. In FIG. 1( a ) liquid solder glass 10 is deposited as marginal bands on the surfaces of two glass sheets 12 , 14 . In FIG. 1( b ) the glass sheets 12 , 14 are then tempered to establish the necessary stresses within the glass sheets 12 , 14 for heat strengthening the same. During the tempering process, the solder glass 10 melts and forms an hermetic bond to the surface of the glass sheets 12 , 14 . This bond is achieved by interdiffusion of the atoms of the solder glass 10 and the glass sheets 12 , 14 , typically over a distance of approximately 0.1 μm. As the temperature is decreased at the end of the tempering process, the solder glass solidifies.
[0023] The two tempered glass sheets are then assembled into a configuration illustrated in FIG. 1( c ), with the bands of solidified solder glass 10 being positioned on top of each other. In the configuration illustrated in FIG. 1( c ), an array of support pillars 16 has been provided on the bottom glass sheet 14 . The sum of the thicknesses of the two bands of solidified solder glass 10 is slightly greater than the height of the support pillars 16 . During a second heating process, the bands of solidified solder glass 10 are softened and melted sufficiently to form a hermetic seal between them. At the required temperature, the solder glass 10 softens sufficiently that it deforms, permitting the upper glass sheet 12 to move towards glass sheet 14 until it contacts the support pillars 16 , as illustrated in FIG. 1( d ). After cooling down from the second heating process, a hermetic seal 18 exists between the edges of the glass sheets 12 , 14 around their periphery. The second heating process occurs at a lower temperature, and for a shorter time, than is necessary to produce the hermetic bond between the solder glass 10 and the glass sheets 12 , 14 during the first heating process (FIG. 1( b )), with the temperature of the second heating process being sufficiently low to avoid a significant relaxation of the stresses within the glass sheets 12 , 14 to maintain their heat-strengthened property.
[0024] The bands of solidified solder glass 10 melt and fuse into a non-porous material during the second heating process, and fuse to each other at a lower temperature than that required for significant interdiffusion to occur between the atoms of the bands of solder glass 10 and the glass sheets 12 , 14 .
[0025] For glass sheets made from soda lime glass, the solder glass used would for example have a “conventional” specification of being fusible with soda lime glass at 450-480° C. for one hour, or at higher temperatures for a shorter time. The tempering process will be chosen to cover those specifications. However, the second heating process, i.e. the fusing of the bands of solder glass 10 , can be performed at 440° C., preferably 350° C. for one hour, thereby avoiding a significant stress relaxation in the tempered glass sheets during the second heating process.
[0026] Turning now to FIG. 2( a ), in an alternative embodiment marginal bands of solder glass 20 , 22 are deposited on to glass sheets 24 , 26 , respectively, with the band of solder glass 22 on one of the sheets 26 being wider than the other. The glass sheet 26 is dimensioned to exceed a width of the glass sheet 24 at any point around the periphery of glass sheet 24 .
[0027] Both sheets 24 , 26 are then tempered and during the tempering process, hermetic bonds are formed between the bands of solder glass 20 , 22 and the glass sheets 24 , 26 , respectively (see FIG. 2( b )).
[0028] The sheets 24 , 26 are then assembled into a configuration as illustrated in FIG. 2( c ), with the bottom sheet 26 protruding the upper sheet 24 at any point around the circumference of glass sheet 24 . In the configuration illustrated in FIG. 2( c ), an array of support pillars 28 is provided between the glass sheets 24 , 26 with a combined thickness of the bands of solder glass 20 , 22 being slightly less than a height of the support pillars 28 .
[0029] Next, a further band of solder glass 30 in a liquid paste form is deposited around the periphery of the upper glass sheet 24 , on top of the band of solder glass 22 , as illustrated in FIG. 2( d ).
[0030] The entire structure is then subjected to a second heating process during which the band of solder glass 30 is softened and melted to fuse both to itself to form an impermeable layer, and to each of the bands of solder glass 20 , 22 (FIG. 2( e )). This melting and fusing operation takes place at a substantially lower temperature, and over a shorter time, than is necessary to form a hermetic bond between the solder glass 20 , 22 and the glass sheets 24 , 26 directly (FIG. 2( b )).
[0031] In this embodiment, the final separation of the glass sheets 24 , 26 is “automatically” controlled to be equal to the height of the support pillars 16 , without having to allow for sufficient deformation of the bands of the solder glass 10 to ensure “complete” lowering of the upper sheet 14 as described for the other embodiment (see FIG. 1. It will be appreciated by a person skilled in the art that numerous variations and/or modifications may be made to the present invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects to be illustrative and not restrictive.
[0032] For example, the further solder glass band used for forming an hermetic seal between the pre-deposited bands of solder glass on both glass sheets does not necessarily require one of the glass sheets to be larger than the other. Rather, the further solder glass band may be deposited “directly” on the peripheral side of equally dimensioned glass sheets in the area between the glass sheets.
[0033] As another example, the further solder glass can be the same solder glass as used for the pre-deposited solder glass bands, or may be a different solder glass with different specifications. | A method of constructing a glass panel which comprises two confronting edge sealed glass sheets, the method comprises the steps of providing a solder glass band around the margin of one surface of each glass sheet, forming, at a first temperature, an hermetic bond between the solder glass band and the associated surface of each glass sheet, positioning the glass sheets in spaced-apart confronting relationship, forming, at a second temperature which is lower than the first temperature, an hermetic seal between the two solder glass bands whilst maintaining the spaced apart relationship between the glass sheets. | 8 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to a corrugating machine for the manufacture of sheets of corrugated board, comprising at least two unroll stands for unwinding webs of material from reels of material; at least one fluting unit for the manufacture of at least one corrugated medium from one of the webs of material; at least one processing equipment for uniting the corrugated medium and at least another web of material to form a web of corrugated board; a cutting station for cutting the sheets of corrugated board from the web of corrugated board; and a method for the manufacture of sheets of corrugated board on a corrugating machine, comprising the steps of providing a corrugating machine which comprises at least two unroll stands for unwinding continuous webs of material as well as at least one processing equipment for producing at least one web of corrugated board from the webs of material; digitally printing at least one web of material on the corrugating machine; and cutting the sheets of corrugated board from the digitally printed web of corrugated board in accordance with the shape and size of digitally imprinted patterns.
[0003] 2. Background Art
[0004] Corrugating machines for the manufacture of single-faced corrugated board or multi-layer corrugated board are for example known from U.S. Pat. No. 5,632,850. There is a frequent demand for printed sheets of corrugated board. Simple and flexible solutions have not been known so far.
SUMMARY OF THE INVENTION
[0005] It is an object of the invention to develop a corrugating machine of the type mentioned at the outset in such a way that simple printing of the corrugated board is possible, in particular for working rather small printing jobs.
[0006] According to the invention, this object is attained in a corrugating machine wherein at least one digital printing system for printing at least one of the webs is disposed between the unroll stands and the cutting station. The gist of the invention resides in digitally imprinting the webs during manufacture of the corrugated board, even before the sheets are cut to size, in a corrugating machine. Prints can be applied to the web rather flexibly, in particular true to pattern. In particular, it is possible to handle rather small printing jobs, imprinting varying patterns on the webs being feasible without exchange of hardware components of the printing system. The patterns can be printed in various directions, in particular lengthwise and crosswise of the web conveying direction, with varying scaling. It is even possible to print a web of single-faced corrugated board on the side of the corrugated medium, which is not feasible when printing cylinders are used. Any subsequent printing of the sheets of corrugated board or printing of reels of material that are kept in the corrugating machine prior to operation can be dropped.
[0007] In a corrugating machine with the printing system disposed upstream of the processing equipment seen in a direction of production, the webs of material are printed while single i.e., not united, in the corrugating machine. This reduces the demands on the printing system because material of comparatively little thickness can be worked.
[0008] With printing taking place upstream of a heater which is anyway necessary for the production of corrugated board, this will automatically provide for the print on the webs of material to dry.
[0009] Printing flexibility is further improved by the possibility of bilateral printing. A single printing unit serves to print bilaterally, or two displaced printing units may be used, a first unit printing one side and a second unit printing the other. The bilateral print can be applied to the united web of corrugated board or even before, with two webs of material being unilaterally imprinted and then united to form the web of corrugated board.
[0010] Details of the invention will become apparent from the ensuing description of several exemplary embodiments, taken in conjunction with the drawing.
BRIEF DESCRIPTION OF THE DRAWING
[0011] [0011]FIG. 1 is a view of a first part of a corrugating machine according to a first embodiment;
[0012] [0012]FIG. 2 is a view of a detail of FIG. 1, on an enlarged scale, in the vicinity of a first web of material;
[0013] [0013]FIG. 3 is a plan view of a detail of the first web of material in the vicinity upstream of a heater in the first part of the corrugating machine;
[0014] [0014]FIG. 4 is a plan view of a detail of the first web of material downstream of the heater in the first part of the corrugating machine;
[0015] [0015]FIG. 5 is a plan view of details of a printed web of material;
[0016] [0016]FIG. 6 is a view of a second part of the corrugating machine according to the first exemplary embodiment;
[0017] [0017]FIG. 7 is a view of a second part of a corrugating machine according to a second exemplary embodiment;
[0018] [0018]FIG. 8 is a view of a first part of a corrugating machine according to a third exemplary embodiment;
[0019] [0019]FIG. 9 is a view of a second part of a corrugating machine according to the third exemplary embodiment;
[0020] [0020]FIG. 10 is a view of a first part of a corrugating machine according to a fourth embodiment; and
[0021] [0021]FIG. 11 is a view of a second part of the corrugating machine according to the fourth embodiment.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0022] The following is a description of a first embodiment of the invention, taken in conjunction with FIGS. 1 to 6 . A corrugating machine as diagrammatically plotted in FIGS. 1 and 6 comprises a machine 1 for the manufacture of single-faced corrugated board. From a first unroll stand 2 , a first web of material 3 is fed to the machine 1 . The webs of material are continuous paper webs. The web of material 3 constitutes a backer web for the corrugated board manufactured on the machine 1 . FIG. 2 is a side view, on an enlarged scale, of the first web of material 3 in detail. It comprises a backer 3 a with a primer 3 b which improves the printing quality. The backer 3 a to primer 3 b thickness ratio is not true to scale in FIG. 2. In practice, the primer 3 b is substantially thinner as compared to the backer 3 a than shown in FIG. 2. The primer 3 b must not necessarily be available in a form applied to the web of material 3 when it is rolled up; it can just as well be applied to the web of material 3 later upon unwinding.
[0023] Between the first unroll stand 2 and the machine 1 , the first web of material 3 passes through a first digital printing unit 4 with an ink jet head 5 which prints the top side of the first web of material in accordance with a printing job. Via a signal line 6 , the printing unit 4 is in connection with an application control unit 7 .
[0024] In the machine 1 , the printed first web of material 3 is united with a second web of material 8 which is supplied from a second unroll stand 9 . When unrolled, the second web of material 8 passes between two adjacent fluted rollers 10 which are allocated to each other for producing a corrugation. After passing there-through, the second web of material 8 is available in the form of a corrugated medium 8 . Then adhesive is applied to the tips of the medium 8 in an adhesive applicator unit 11 , and the medium 8 and the first web of material 3 are pressed together and united in a nip between a nip roller 12 and one of the fluted rollers 10 . Consequently, the machine 1 is a first production unit of a processing equipment 42 for uniting webs of material to form a web of corrugated board. A single-faced web of corrugated board 13 is discharged upwards from the machine 1 and deflected about a deflection roller 14 into a working direction 15 . The machine 1 for the manufacture of single-faced corrugated board is generally known for example from U.S. Pat. No. 5,632,850, GB 2 305 675 A or DE 43 05 158 A1, to which reference is made for details.
[0025] [0025]FIGS. 3 and 4 illustrate details of the first web of material 3 in a plan view. FIG. 3 shows the web of material 3 prior to it passing, in the working direction 15 , through a pre-heater 16 downstream of the deflection roller 14 . The first web of material 3 marginally comprises first marks 17 which are equidistant division marks that extend crosswise of the working direction 15 . Upstream of the pre-heater 16 , two adjacent first marks 17 have a distance a 1 from each other. At regular distances in the working direction 15 , the first web of material further comprises stripes of second marks 18 which are equidistant short division marks that are parallel to the working direction 15 . Upstream of the pre-heater 16 , two adjacent marks 18 have a distance b 1 from each other. FIG. 4 shows the web of material 3 in an illustration similar to FIG. 3 downstream of the pre-heater 16 . The distance between two adjacent first marks 17 is a 2 and the distance between two adjacent second marks 18 is b 2 . Owing to shrinkage of the web of corrugated board 13 after being heated in the pre-heater 16 and owing to the modifications, resulting therefrom, in the dimensions of the web of material 3 , the following applies to the distances: a 2 <a 1 and b 2 <b 1 .
[0026] A reader 19 , which is disposed above the web of corrugated board and thus above the top side of the first web of material 3 that carries the marks 17 , 18 and between the deflection roller 14 and the pre-heater 16 , determines the distances a 1 and b 1 between adjacent marks 17 , 18 . To this end the reader 19 is similar to a bar code scanner. Via a signal line 20 , the reader 19 is in connection with the application control unit 7 .
[0027] A second unroll stand 21 for a third web of material 22 as another liner of the single-faced web of corrugated board 13 is disposed downstream of the machine 1 in the working direction 15 . The corrugated medium 8 , the first web of material 3 which is the backer web, and the third web of material 22 which is the liner web are suitably selected paper webs. In part, it is also usual to call the third web of material 22 the liner web, with the first web of material 3 in this case being called primer web. The webs of material 3 , 8 and 22 are unrolled at a speed of up to 400 m/min.
[0028] Downstream of the second unroll stand 21 , the third web of material 22 is first deviated about a deflection roller 23 so that it runs in the working direction 15 . Then the third web of material 22 is deviated by 180° by another two deflection rollers 24 , 25 so that the side that faces downwards between the deflection rollers 23 and 24 is now turned upwards, the third web of material 22 , downstream of the deflection roller 25 , running counter to the working direction 15 . Downstream of the deflection roller 25 , the third web of material 22 passes through a second printing unit 26 which cooperates with the first printing unit 4 , forming a digital printing system 27 . The side of the third web of material 22 that is turned upwards downstream of the deflection roller 25 is printed by an ink jet head 28 in the printing unit 26 , in accordance with a printing job. The third web of material 22 is also of two-layer design, having a backer and a primer such that the ink jet head 28 of the second printing unit 26 imprints the primer of the third web of material 22 . The primer of the third web of material can also be applied after being unrolled and upstream of the second printing unit 26 .
[0029] For print application control, the second printing unit 26 is in connection with the application control unit 7 via a signal line 29 . After passing the second printing unit 26 , the third web of material 22 , by the aid of another two deflection rollers 30 , 31 , is again deflected substantially by 180° so that downstream of the deflection roller 31 , the third web of material 22 again runs substantially in the working direction 15 .
[0030] Downstream of the deflection roller 31 , the third web of material is fed to the pre-heater 16 . The pre-heater 16 comprises two heating rollers 32 that can be heated and are disposed one on top of the other. The single-faced web of corrugated board 13 and the third web of material 22 run one on top of the other, partially being in contact with the respective heating rollers 32 . An adhesive applicator unit 33 is disposed downstream of the pre-heater 16 , having an adhesive roller 33 which partially dips into an adhesive pan 35 . The medium 8 of the web of single-faced corrugated board 13 is in contact with the adhesive roller 34 .
[0031] Downstream of the adhesive applicator unit 33 , provision is made for a heating contact pressure device 36 which comprises a horizontal hot plate table 37 that extends in the working direction 15 . A continuously driven contact pressure belt 39 is provided above the table 37 ; it is deflected by way of three rollers 38 . A nip 40 is formed between the contact pressure belt 39 and the table, with the web of single-faced corrugated board 13 and the third web of material 22 passing through the nip 40 where they are pressed one upon the other. A corresponding heating device 36 is known from DE 199 54 754 A1. A three-layer web of corrugated board 41 is being formed in the heating device 36 . The heating device 36 and the table 37 constitute a second production unit of the processing equipment 42 for uniting webs of material to form a web of corrugated board 41 .
[0032] [0032]FIG. 5 shows two sections of the printed first web of material 3 as part of the web of corrugated board 41 after discharge from the heating device 36 . Various printing patterns 43 are illustrated, which are necessary for printing certain sizes and types of boxes or cartons. As seen in FIG. 5 by way of example, the printing patterns 43 may differ in dimensions lengthwise or crosswise of the working direction 15 .
[0033] The printing patterns 43 are for example advertising imprints, or instructions in the form of folding or cutting stencils, or printed numbers or dates, or imprints dealing with a certain batch of goods that must be wrapped by the aid of the sheets of corrugated board 62 , 67 . They may be clearly worded, readable information or bar codes. Owing to the possibilities of the digital printing system 27 , printing-pattern- 43 variations are virtually unlimited. It is for instance conceivable to design the patterns 43 so that they represent individual parts of an entire picture which originates when sheets 62 , 67 with these individual parts of printing patterns are joined or when wrappings are produced from these sheets.
[0034] [0034]FIG. 6 illustrates a second part of the corrugating machine, following the discharge of the web of corrugated board 41 from the heating device 36 . At the upstream end of FIG. 6, a second reader 44 is disposed above the web of corrugated board 41 . The reader 44 is in connection with the application control unit 7 via a signal line 45 illustrated by dashes in FIG. 6. The second reader 44 registers the top side of the web-of-material- 3 section seen in FIG. 4. The second reader 44 measures the distances a 2 , b 2 between adjacent first marks 17 and adjacent second marks 18 .
[0035] Downstream of the reader 44 —seen in the working direction 15 —a lengthwise cutting/grooving unit 46 is disposed, consisting of two successive grooving stations 47 and two successive lengthwise cutting stations 48 . The grooving stations 47 have grooving tools 49 which are arranged in pairs one on top of the other, with the web of corrugated board 41 passing there-between. The lengthwise cutting stations 48 have rotatably drivable cutters 50 which are movable into engagement with the web of corrugated board 41 for it to be cut lengthwise. The detailed design of the lengthwise cutting/grooving unit 46 is known from U.S. Pat. No. 6,071,222 and DE 101 31 833 A which reference is made to for further details of design.
[0036] Downstream of the lengthwise cutting/grooving unit 46 —seen in the working direction 15 —provision is made for a shunt 51 where lengthwise cut sections 52 , 53 of the web of corrugated board 41 are separated. The web sections 52 , 53 are then fed to a cross-cutting unit 54 . It comprises a pair of top crosscutting rollers 55 for the top web section 52 and a pair of bottom crosscutting rollers 56 for the bottom web section 53 . The rollers of the pairs of rollers 55 , 56 each have a cutter bar 57 which is perpendicular to the working direction 15 , extending radially outwards. The cutter bars 57 of a pair of crosscutting rollers 55 , 56 cooperate for crosscutting the web sections 52 , 53 . A top conveyor belt 58 is disposed downstream of the top pair of crosscutting rollers 55 ; it is deviated by rotatably drivable rollers 59 . Downstream of the top conveyor belt 58 , provision is made for a place of deposit 60 with a vertical stop 61 where sheets of corrugated board 62 , which have been cut from the web section 52 by means of the crosscutting unit 54 , are piled up, forming a stack 63 . As roughly outlined by an arrow 64 in FIG. 6, the place of deposit 60 is adjustable in height. For further dispatch of the stack 63 , the place of deposit 60 can in particular be lowered as far as to a bottom 65 that supports the corrugating machine.
[0037] Another bottom conveyor belt 66 is disposed downstream of the pair of crosscutting rollers 56 , stacking sheets of corrugated board 67 on another place of deposit 68 ; the sheets are cut from the web section 53 by means of the crosscutting unit 54 . For adaptation to the height of the stack 63 , the bottom conveyor belt 66 can be lifted as roughly outlined by the arrow 68 a.
[0038] Printing the web of corrugated board 41 with patterns 43 takes place as follows: First the webs of material are provided with primers and supplied to the unroll stands 2 and 21 . The primers may also be dropped, in which case a non-coated web of material is made available at the unroll stand 9 . By alternative, the primer can also be applied directly upstream of the printing units 4 , 26 after the webs of material have been unrolled. The marks 17 , 18 are applied by the printing unit 4 . Then the corrugating machine starts running, producing a non-printed web of corrugated board 41 . This continues until the web of corrugated board that is produced has reached the area where it is registered by the second reader 44 . The two readers 19 , 44 then register the distances a 1 , b 1 and a 2 , b 2 of the marks 17 and 18 . The readers 19 , 44 then pass this information to the application control unit 7 . Based on the ratio a 2 /a 1 of the distances of the marks 17 upstream and downstream of the heating devices 16 , 36 , a computer of the application control unit 7 determines a degree of longitudinal shrinkage of the webs of material 3 , 8 , 22 in the working direction 15 , i.e. a modification of the web dimensions in the longitudinal direction between the web in the vicinity of the first printing unit 4 of the printing system 27 on the one hand (reader 19 ) and the web prior to the sheets 62 , 67 being cut on the other hand (reader 44 ). Correspondingly, cross-shrinkage of the webs of material 3 , 8 , 22 is determined by the aid of the ratio of the distances b 1 , b 2 of adjacent marks 18 in the vicinity of the reader 19 on the one hand and in the vicinity of the reader 44 on the other. Determining the cross shrinkage can be dropped as well as the associated marks. The distance parameters a 1 , a 2 , b 1 , b 2 are transmitted by the readers 19 , 44 to the application control unit 7 .
[0039] The degrees of shrinkage of the web of corrugated board 41 in the longitudinal and cross direction, which are determined by the application control device 7 , serve for the application control device 7 to determine scaling factors for the printing pattern 43 that will be applied by the printing units 4 and 26 . The printing units 4 and 26 apply the printing patterns 43 by dimensional reservation so that the desired size of the printing patterns 43 will appear on the web sections 52 , 53 owing to the pre-determined shrinkage of the web. Simultaneously, the application control unit 7 , via signal lines (not shown), controls the lengthwise cutting stations 48 on the one hand and the crosscutting unit 54 on the other in accordance with the printing jobs transmitted by the application control unit 7 to the printing system 27 . The sheets of corrugated board 62 , 67 are cut in such a way that the printing patterns 43 are located at pre-determined places on the sheets 62 , 67 . The printing jobs transmitted from the application control unit 7 to the printing system 27 may involve small or minimal serial manufacture of only few sheets of corrugated board 62 , 67 . Upon modification of the printing job, the lengthwise cutting stating 48 is triggered by the application control unit 7 so that the width of the web sections 52 , 53 is cut correspondingly. Instead of the illustrated cross-cutting unit 54 with pairs of rollers 55 , 56 , use can be made of a cross-cutting unit which is equally triggered by the application control unit 7 , enabling sheets of corrugated board of varying lengths to be cut in the working direction 15 . The sheets of corrugated board 62 , 67 can then be adapted in size perfectly flexibly to the shape and size of the printing patterns 43 of the respective printing jobs.
[0040] If necessary, prior to being printed, the sides of the webs of material 3 , 22 that are to be printed can be cleaned by a corresponding equipment, for instance a compressed air sprayer. Sucking off is conceivable alternatively of blowing off the sides, to be printed, of the webs of material 3 and 22 . Finally, it is also possible to prepare the webs of material 3 , 22 in such a way that they are antistatic, dust being prevented from depositing on the sides that are to be printed. Preferably, printing the webs of material 3 , 22 takes place in an air-conditioned environment. The temperature is kept at less than 40° C. Once the webs of material 3 , 22 have been printed, the printed sides can be sealed by a corresponding protective layer being applied. This type of sealing can take place prior to or after the sheets of corrugated board 62 , 67 are cut.
[0041] [0041]FIG. 7 illustrates a second part of a corrugating machine according to a second embodiment. FIGS. 8 to 11 illustrate further embodiments of corrugating machines. Components that correspond to those described with reference to FIGS. 1 to 6 have the same reference numerals and are not going to be explained in detail again.
[0042] In the corrugating machine according to the second embodiment, a digital printing system 69 is disposed downstream of the heater (not shown). With no relevant shrinkage of the web taking place between the jobs of printing the web of corrugated board 41 and depositing the cut sheets of corrugated board 62 , 67 , the readers 19 , 44 of the first embodiment can be dropped.
[0043] In the second exemplary embodiment, a reader 70 is disposed upstream of the lengthwise cutting/grooving unit 46 , crosswise scanning the web of corrugated board 41 and recognizing the distribution of printing patterns 43 on the web of corrugated board 41 . Signal lines 71 , 72 provide for signalling connection of the reader 70 with the lengthwise cutting stations 48 . Depending on recognition of the printing patterns 43 by the reader 70 , the lengthwise cutting stations 48 are triggered for web sections 52 , 53 to be cut, having a width that corresponds to the arrangement of the printing patterns.
[0044] Another reader 73 is disposed between the lengthwise cutting/grooving unit 46 and the cross-cutting unit 54 , within its range scanning the web sections 52 , 53 of the web of corrugated board in the working direction 15 i.e., lengthwise, and registering the distribution of printing patterns 43 on the web of corrugated board 41 in the working direction 15 . A signal line 74 connects the reader 73 with the cross-cutting unit 54 . Corresponding to what has been said about lengthwise cutting of the web of corrugated board 41 , the reader 73 triggers the cross-cutting unit 54 in such a way that this unit 54 cuts the sheets of corrugated board 62 , 67 in accordance with the distribution of printing patterns in the working direction 15 . By the aid of the readers 70 . 73 , a plane shape of the sheets of corrugated board can be determined, the longitudinal and transverse dimensions of which are adjustable; this plane shape can be cut to size by the lengthwise cutting stations 48 and the cross-cutting unit 54 being correspondingly triggered.
[0045] In variation of the second embodiment, printing units may be provided in addition to the printing system 69 , corresponding to the printing units 4 and 26 of the first embodiment for printing individual webs of material upstream of the machine 1 or the heating device 36 .
[0046] In further variation of the second embodiment, the printing system 69 can be provided with two ink jet heads in such a way that the web of corrugated board 41 is bilaterally printed, i.e. simultaneously on the top and bottom side.
[0047] [0047]FIGS. 8 and 9 show the two parts of a corrugating machine according to a third embodiment. As compared to the first embodiment, the second printing unit 26 misses in the first part, seen in FIG. 8, of the corrugating machine. Also the deviation of the third web of material by the deflection rollers 23 , 24 , 25 , 30 , 31 has been dropped, which is no longer needed. Further, the first reader 19 misses in the third embodiment. The application control unit exists also in this embodiment, however it is not shown. In the corrugating machine of the third embodiment, a first web of material 3 is being printed, having marks 17 , 18 at an initial distance that is given and has been fed into the application control unit of the third embodiment prior to the start of production of the corrugating machine. Therefore the application control unit of the third embodiment knows the distances a 1 , b 1 although they have not been measured by a reader.
[0048] The second part of the third embodiment of the corrugating machine seen in FIG. 9 corresponds to the second part of the corrugating machine of the first embodiment seen in FIG. 6, a difference residing in that the reader 44 of the first embodiment, which evaluates the distance from each other of the marks 17 and the marks 18 , is functionally split into a first reader 75 for determination of the distance of the marks 17 and a second reader 76 for determination of the distance of the marks 18 . Signal lines (not shown) connect the readers 75 , 76 to the application control unit of the corrugating machine of the third embodiment.
[0049] [0049]FIGS. 10 and 11 illustrate the two parts of a corrugating machine of a fourth embodiment. These parts correspond to those of the third embodiment with the difference that the web of corrugated board, in the fourth embodiment, is printed from below instead of from above. Therefore, the printing unit 4 misses in the first part of the corrugating machine of the fourth embodiment. It is replaced by the printing unit 26 which corresponds to the first embodiment, serving for printing the bottom side of the third web of material 22 . Correspondingly, in the second part of the corrugating machine of the fourth embodiment, the readers 75 , 76 are located underneath the web of corrugated board 41 , there registering the printing patterns imprinted by the printing unit 26 . Otherwise, the fourth embodiment corresponds to the third embodiment.
[0050] The readers 19 , 44 , 70 , 73 , 75 , 76 may be embodied as a camera, in particular a CCD camera. In addition to the function described above, the reader 19 still has the function of synchronizing the two printing units 4 , 26 when bilaterally accurately aligned printing is to take place on the web of corrugated board 41 . To this end, the reader 19 registers the time when a certain printing pattern 43 finds itself within in the range of the reader 19 . Depending on the difference of the conveying paths of the web of single-faced corrugated board 13 from the reader 19 as far as to the nip 40 on the one hand and of the third web of material 22 from the ink jet head 28 as far as to the nip 40 on the other hand, the application control unit 7 computes the instant at which the printing unit 26 must print the third web of material 22 for this third web 22 to be printed true to the position of the print on the opposite side of the web of corrugated board, which is the top side of the web of corrugated board 13 that is printed by the printing unit 4 . | A corrugating machine serves for the manufacture of sheets of corrugated board. It comprises at least two unroll stands for unwinding webs of material. A fluting unit is provided for producing at least one corrugated medium from one of the webs of material. A processing equipment serves for uniting the webs of material to form a web of corrugated board. The sheets of corrugated board are cut to size in a cutting station. At least one digital printing system for printing at least one of the webs is disposed between the unroll stands and the cutting station. One of the webs of material can have a coating for improved printing quality. Methods are specified for digitally printing within the corrugating machine, which, upon printing, allow for any modification of dimensions during manufacture of the web of corrugated board; and which enable synchronized printing of opposite sides of the web of corrugated board to take place; and which enable the sheets of corrugated board to be cut in dependence on a printing job. This ensures rather flexible high-quality printing of the sheets of corrugated board. | 1 |
CROSS REFERENCE TO RELATED APPLICATION(S)
The present application is a continuation of U.S. patent application Ser. No. 10/634,025 filed Aug. 4, 2003 now U.S. Pat. No. 7,000,428, which is a continuation of U.S. patent application Ser. No. 09/827,028 filed Apr. 4, 2001, now U.S. Pat. No. 6,601,965, which is a continuation-in-part of U.S. patent application Ser. No. 09/498,523 filed Feb. 4, 2000, now abandoned.
BACKGROUND OF THE INVENTION
1. Technical Field
This invention relates to jewelry. More particularly, this invention pertains to a necklace or bracelet that includes an illuminated medallion.
2. Description of the Prior Art
There exists a substantial market for jewelry of a whimsical nature. Unfortunately, the design of jewelry that can be sold at mass market prices while offering an eye catching effect, such as artificial luminance, is complex and difficult. To achieve such an effect, the jewelry must include a power source, preferably compact. In addition, inexpensive prior art jewelry incorporating a battery-powered device has generally been of limited useful life since inexpensive designs fail to permit battery replacement.
SUMMARY OF THE INVENTION
The present invention addresses the foregoing and other shortcomings of the prior art by providing an article of jewelry. Such article includes an elongated flexible conductor having an exterior coating of non-conductive composition. The conductor comprises a loop having first and second internal discontinuities. A clasp is located within the first discontinuity and a medallion is located within the second discontinuity. The clasp includes a battery in electrical communication with the conductor, and the medallion includes an electro-luminous device in electrical communication with the conductor.
The preceding and other features and advantages of the present invention shall become further apparent from the detailed description that follows. Such description is accompanied by a set of drawing figures in which numerals, corresponding to those of the written description, are associated with the features of the invention. Like numerals refer to like features throughout both the written description and the drawing figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a necklace incorporating the invention superimposed upon a wearer shown in shadow outline;
FIG. 2 is a cross-sectional view of the coated conductor of the invention;
FIG. 3 is an exploded side elevation view of the clasp of an article of jewelry in accordance with the invention, according to the preferred embodiment of this invention, and is suggested for printing on the first page of the issued patent;
FIG. 4 is a side elevation view in cross-section of an assembled clasp in accordance with the invention; and
FIG. 5 is a cross-sectional view of the luminous medallion of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Technical Details
Turning to the drawings, FIG. 1 is a perspective view of a necklace 10 incorporating the invention superimposed upon a wearer shown in shadow outline. The necklace 10 generally comprises a coated conductor 12 comprising, as shown in the cross-sectional view of FIG. 2 , an internal conductor or wire 14 having a coating 16 of appropriate non-conductive material. An example of a suitable coated conductor is NYLON coated wire. Such a conductor has the advantageous quality of avoiding “kinking” when bent.
Returning to FIG. 1 , the coated conductor 12 is formed into a loop for hanging about a wearer's neck, in the case of the necklace, or wrist, in the case of a bracelet, with discontinuities provided for incorporation of an illuminated medallion 18 and a clasp 20 housing a battery structure. As will be seen, an electrical circuit is formed that includes the battery housed within the clasp 20 , a battery-powered light emitting device of the medallion 18 and the conductor 14 . Such electrical circuit actuates the medallion to emit illumination when energized by the closing of the clasp 20 . Thus the clasp 20 serves both to secure the necklace 10 and to house a replaceable battery. By allowing battery replaceability, the useful life of the necklace 10 is not limited by that of the battery, permitting the fabrication of higher quality jewelry as opposed to the lower quality “throw away” items of the prior art.
FIG. 3 is an exploded side elevation view of the clasp 20 of the invention and FIG. 4 is a side elevation view in cross-section of the clasp 20 when the assembly is closed. The clasp 20 has been carefully designed to facilitate the ready removal and replacement of a battery 22 that provides the power for illuminating the medallion 18 . The battery 22 is preferably of the nickel cadmium type characterized by an anode surface 24 of less diameter than the cathode surface 26 .
The clasp 20 includes coacting upper and lower caps 28 and 30 , preferably of molded plastic or other resilient material, respectively. The caps 28 , 30 of the small and unobtrusive clasp 20 are particularly designed to facilitate easy access to the interior of the chamber formed therebetween for battery 22 removal and/or replacement. Each cap 28 , 30 includes a rim 32 and 34 , respectively, that protrudes outside the diameter of a sidewall. In the case of the upper cap 28 , the rim 32 protrudes outside the outer diameter of an annular sidewall 36 while, in the case of the lower cap 30 , the rim 34 protrudes outside the outer diameter of a sidewall 38 .
The rims 32 and 34 greatly facilitate the ability of one to grasp the caps 28 and 30 independently. In addition, as can best be seen in FIG. 4 , the clasp 20 has been carefully dimensioned so that, when closed, the sidewall 38 of the lower cap 30 is forced outwardly by the maximum outer diameter of the enclosed battery 22 so that a press-fit is obtained with the interior of the sidewall 36 of the upper cap 28 . Such interaction is obtained by careful dimensioning of the inner diameter of the sidewall 38 with the dimensions of the battery 22 and the outer diameter of the sidewall 38 with the inner diameter of the sidewall 36 .
In addition to the locking arrangement illustrated in FIG. 4 , a tight pressure fit exists between the battery 22 and the interior of the rim 34 of the lower cap 30 that retains the battery 22 within the clasp 20 even when the two caps 28 and 30 are disengaged from one another. This permits one to use and wear the device as an ordinary piece of jewelry, unlocking the clasp 20 to remove the necklace, for example, from one's neck without concern that the battery 22 will be lost.
When battery replacement is required, this is easily accomplished by pushing a thin rod-like element upward through an aperture 40 that is provided in a bottom area of the lower cap 30 within the thickened central area of the rim 34 circumscribed by the inner circumference of the sidewall 38 .
Electrodes 42 , 44 are received within central recesses 46 , 48 at the thickened inner surfaces of the rims 32 and 34 respectively. Each of the rims 32 and 34 includes a tunnel 50 , 52 for receiving an end of the coated conductor 12 adjacent to a loop discontinuity. Referring to FIG. 4 in particular, it can be seen that the portions of the ends of the coated conductor 12 interior to the rims 32 and 34 are stripped to exposed the conductor wire 14 . The wire 14 is, in each case, joined to an electrode 42 or 44 , after being threaded through one of the tunnels 50 , 52 by crimping with a metal crimp bead to form a flat, square contact that cannot transverse backward through the tunnel 50 or 52 as each bead assembly is much larger than the tunnel through which it was originally received. As a result, no adhesives for securing either electrodes or wires are required within the interior of the clasp 20 .
FIG. 5 is a cross-sectional view of the medallion 18 of the necklace 10 . The medallion 18 comprises a spherical bead 54 , smooth or faceted, of transparent or translucent, clear or tinted, material that receives end of the coated conductor 12 in the region of a second loop discontinuity. The ends of the coated conductor 12 , stripped to expose the interior conductor wire 14 , electrically contact positive and negative terminal receptors 56 and 58 of a light emitting diode (LED) 60 . The LED 60 is of the surface mounted type, permitting the arrangement as shown in FIG. 5 and may comprise, for example, a device commercially available under Part No. KPT 2021 HD from Kingbright Corporation of City of Industry, California. Such a LED is available in red, blue, green, amber, and white. The invention is, however, not limited to such a LED.
The bead 54 of the medallion 18 includes a diametrical hole 62 forming a channel therethrough. To assemble, the LED 60 is inserted into the channel after insertion of the surface mounted LED therein with positive and negative terminal receptors 56 and 58 facing opposed channel entrances. The exposed conductor 14 at the ends of the stripped coated conductor 12 are separately inserted into the end of the channel to contact the LED 60 . Once contact is made with one of the opposed terminals, an appropriate non-conductive adhesive, such as silicone glue, is injected into the channel and allowed to harden to maintain contact between that terminal and the conductor or wire 14 . This process is repeated to obtain secure contact between the wire 14 and each of the terminal receptors 56 and 58 , resulting in a simple, yet rugged configuration. The use of silicone glue assures that the channel will remain clear and in no way affect the appearance of the bead 54 when illuminated.
Employing a surface mounted LED 60 enables the use of a small bead-like medallion 18 that is illuminated from within. This is to be contrasted with illuminated medallion-type ornamentation that employs bullet mounted LEDs such as that taught in U.S. Pat. No. 6,122,933 issued to Stephen K. Ohlund on Sep. 26, 2000 for “Jewelry Piece”. Such LEDs operate at a higher voltage (requiring the use of multiple batteries and thereby necessitating a bulkier clasp) and, as in the above patent, requiring an arrangement other than the simple and durable arrangement of the invention in which wires enter into the interior of a bead to contact opposite sides of a LED. This is due to the fact that bullet-mounted LEDs are bulkier (approximately 0.75 mm vs. 3 mm in cross section) than surface mounted LEDs and the output pins of such LEDs are parallel to one another, exiting the LED from the same side. Such terminal configuration prevents the mounting of such a source wholly within a small bead as in the invention. The mounting of the light source wholly within a relatively small bead 54 generates a more brilliant and dramatic effect than possible in devices limited to indirect illumination as a consequence of the use of bullet type LED sources such as that of U.S. Pat. No. 6,122,933.
When assembled, the necklace 10 (alternatively, a bracelet may be formed with a shortened coated conductor 12 ) is then operable as a piece of luminous jewelry with illumination emanating through the bead 54 of the medallion 18 since the LED 60 is in electrical contact with the battery 22 power supply through the conductor 14 when the clasp 20 is closed and secured as shown in FIG. 4 .
While this invention has been described with reference to its presently-preferred embodiment, it is not limited thereto. Rather, the invention is limited only insofar as it is defined by the following set of patent claims and includes within its scope all equivalents thereof. | A necklace or bracelet includes a luminous medallion. A conductor having a coating of non-conductive material is formed into a loop having two discontinuities. A clasp that houses a removable battery is fixed within the first discontinuity and a bead having an internally embedded LED is located within the second discontinuity. Electrical connections are made to electrodes located within the clasp by interior electrical conductors exposed at the stripped ends of the coated conductors that define one discontinuity. The conductors are fixed in electrical contact with the LED at the other discontinuity at the stripped ends of the coated conductor in the region of the second discontinuity. | 0 |
CROSS-REFERENCED APPLICATIONS
[0001] The present disclosure is a continuation of and claims priority to U.S. patent application Ser. No. 13/683,760, filed Nov. 21, 2012, now U.S. Pat. No. 8,566,660, issued Oct. 22, 2013, which is a continuation of U.S. patent application Ser. No. 13/277,740, filed Oct. 20, 2011, now U.S. Pat. No. 8,321,731, issued Nov. 27, 2012,which is a continuation of U.S. patent application Ser. No. 13/028,033, filed Feb. 15, 2011, now U.S. Pat. No. 8,046,652, issued Oct. 25, 2011, which is a continuation of U.S. patent application Ser. No. 12/197,004, filed Aug. 22, 2008, now U.S. Pat. No. 7,890,828, issued Feb. 15, 2011, which is a continuation of U.S. patent application Ser. No. 09/917,972, filed Jul. 30, 2001, now U.S. Pat. No. 7,418,642, issued Aug. 26, 2008, which are incorporated herein by reference.
BACKGROUND
[0002] Application specific integrated circuits (ASICs) must be tested under a variety of circumstances. For example, during development, an ASIC generally requires thorough testing and debugging to verify or fix the design of the integrated circuit. During production, ASICs generally must be tested to separate good chips from bad chips. During use, an ASIC is often tested to determine whether the integrated circuit is functioning properly in a system.
[0003] One method for testing an ASIC during production uses a traditional ASIC tester such as an Agilent 83000 F330 to apply test patterns to the terminals of the ASIC. The test patterns ideally exercise all of the functional paths of the ASIC and can uncover any defects in the ASIC. Developing the test patterns required for thorough testing can take significant development effort. In particular, developing a test pattern that exercises all functional paths in multiple functional units including embedded memory can be difficult. Additionally, when an ASIC includes an interface to external memory, the test patterns must emulate the external memory, and developing a test pattern that emulates the timing of a high-speed external memory can be time consuming particularly when the ASIC uses a serial interface to reduce pin count.
[0004] Even if an exhaustive test pattern is developed, running through a complex test pattern during testing of an ASIC generally requires time, which potentially increases the manufacturing cost of the ASIC. Less exhaustive test patterns can reduce test times, but simpler test patterns may not catch as many defects, resulting in more defective chips being delivered to customers.
[0005] Another limitation of ASIC tests requiring a tester is that such tests are limited to production or development of the ASICs and generally are impractical for testing of an ASIC in commercial product or system. Accordingly, ASICs need at least two types of tests, a test implemented with an external tester and a built-in self-test (BIST) that the ASIC performs in a product. Developing both tests requires duplicated effort and expense.
[0006] BIST tests are generally implemented using special BIST logic that applies deterministic signal patterns in an attempt to exercise the logic paths. Developing BIST logic that performs exhaustive tests is difficult both because there is no guarantee that the paths exercised are the actual functional paths and because creating the test logic often requires specialized design tools. Once produced, such logic is often complicated, increases the ASICs size and cost, and can be overhead that decreases the ASICs performance.
[0007] In view of the difficulties involved in testing, more efficient testing methods and structures are sought for testing ASICs during development, production, and use.
SUMMARY
[0008] In accordance with an aspect of the invention, an ASIC with an embedded processor executes test routines to test the operation of the ASIC. The test routines can perform at-speed functional tests of circuit blocks such as embedded memory, coders and decoders, and interfaces to external devices. The test implementation requires a small amount of IC area associated with the memory storing the test routines. External test equipment can use a simple test pattern that in one embodiment of the invention only involves three pins of the ASIC. Accordingly, the production testing can be performed quickly with simple test equipment and without burdening the ASIC with complex test logic. Additionally, the same or similar test routines in the embedded memory can be used in a self-test when the ASIC is in a product.
[0009] One embodiment of the invention is an integrated circuit including a processing core and a non-volatile memory containing test routines that the processing core executes to test the integrated circuit. An interface block in the integrated circuit can handle signals associated with testing. In particular, the processing core executes the test routines selected according to control signals input via the interface block.
[0010] In one embodiment, the interface block includes first and second terminals. The processing core use a first signal on the first terminal to indicate a test result, i.e., to indicate whether execution of the test routines detected a defect in the integrated circuit. On the second terminal, the processing core activates a second signal to indicate when the first signal indicates the test result. A third terminal can receive a control signal for selection of the test routines from embedded memory for a production test or a system-level test or for selection of execution of firmware downloaded from external memory.
[0011] Functional blocks in the integrated circuit can include data paths that facilitate software testing of the blocks. For example, an input buffer that normally receives data input from an external source can be connected so that the processor can write to the input buffer to test data flow through the input buffer. To reduce the need for test routines that monitor an entire data stream, check code or CRC calculators can be added to specific units to provide a code that is easily checked to detect errors. Further loop-back capabilities can be added to facilitate testing of the data from in and out of network interfaces.
[0012] Another embodiment of the invention is a test method for an integrated circuit. The test method uses an embedded processing core in the integrated circuit to execute test routines stored in an embedded non-volatile memory in the integrated circuit. The test routines can implement complicated tests such as exhaustive testing of an internal memory or other functional blocks of the integrated circuit and output a signal that a tester observes to determine a test result. Generally, a first signal indicates whether the execution of the test routines detected a failure in the integrated circuit. The processing core in executing the test routines can activate a second signal to indicate when a state of the first signal indicates whether the test routines detected a failure. The first signal can be activated before activation of the second signal to acknowledge or signal that the processing core is executing the test routines. One or more additional signals from the integrated circuit can indicate a type or location of a failure that executing the test routines detected.
[0013] A tester during production testing of the integrated circuit thus has a simple test pattern involving only a few pins but obtains a test result from an exhaustive test implemented in the test routines. Additionally, during use of the integrated circuit in a system the system's circuitry can easily initiate a test of the integrated circuit and monitor results.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a block diagram of an ASIC with self-test capabilities in accordance with an embodiment of the invention.
[0015] FIGS. 2A and 2B are timing diagrams of output signals for a passed self test and a failed self test, respectively.
[0016] FIG. 3 is a flow diagram of an external memory portion of a test process in accordance with the invention.
[0017] FIG. 4 is a block diagram of an ASIC connected to test equipment for production testing in accordance with an embodiment of the invention.
[0018] FIG. 5 is a block diagram of an ASIC in a system capable of system-level testing in accordance with an embodiment of the testing.
[0019] FIG. 6 is a flow diagram of a method 600 for testing an integrated circuit.
[0020] Use of the same reference symbols in different figures indicates similar or identical items.
DETAILED DESCRIPTION
[0021] In accordance with an aspect of the invention, an ASIC with an embedded processor has test routines in an embedded memory. The embedded processor executes the test routines to test the operation of the ASIC. The test routines may be used for ASIC production tests and system-level power-on self-tests. For highly integrated circuits that already contain an embedded ROM, the overhead logic for these self-test functions is minimal.
[0022] FIG. 1 is a block diagram of an ASIC 100 in accordance with an exemplary embodiment of the invention. In FIG. 1 , ASIC 100 is a formatter for a printer and in an end product would participate in communications between a printer and a host computer (not shown). This exemplary embodiment is described here to provide a concrete example of one ASIC application, but broad aspects of the invention can be used more widely in any integrated circuit or ASIC that contains an embedded processor having sufficient processing power to execute test routines. Embodiments of the invention are clearly not limited to integrated circuits containing the specific functional units of ASIC 100 .
[0023] As illustrated in FIG. 1 , ASIC 100 includes a processing core 110 , an internal memory 120 , a general purpose input/output (GPIO) interface 130 and functional units including a codec 140 , an external device interface 150 , a print engine communications unit 160 , a DMA unit 170 , and timing circuits 180 . An arbitrated internal bus 190 conducts communication signals among the various blocks of ASIC 100 .
[0024] Processing core 110 executes instructions that can be stored in internal memory 120 or external memory (not shown). Any type of processor may be suitable for processor 100 , but in an exemplary embodiment of the invention, processing core 110 is an ARM7 processing core, which can be licensed from ARM Ltd.
[0025] Internal memory 120 includes volatile memory such as DRAM 122 and SRAM 124 and non-volatile memory such as ROM 126 . ROM 126 can be any type of non-volatile memory such as a mask ROM, an EPROM, or an EEPROM and stores firmware including but not limited to test routines 128 . An exemplary set of test routines 128 is described further below and generally includes tests of the operation internal memory 120 and associated memory interface circuits and tests of the other functional units 140 , 150 , 160 , 170 , and 180 .
[0026] In the exemplary embodiment, interface 150 operates in a normal mode to implement a universal serial bus (USB) interface for communication with a host computer, but interface 150 can also operate to download firmware as described below. Alternatively, GPIO interface 130 can be used as a memory interface to download firmware from an external memory such as a serial EEPROM. Downloaded firmware can replace all or portions of test routines 128 as described further below. Print engine communications 160 implements a communication interface to a printer, and DMA 170 implements direct memory access for transfer of print images. Codec 140 performs coding and decoding operations on print images.
[0027] GPIO interface 130 provides the control and output interface for self-test functions of ASIC 100 . In particular, GPIO interface 130 employs three signals, ASICTEST, BISTERROR, and BISTDONE. Processing core 110 checks input signal ASICTEST via GPIO interface 130 to determine whether to execute system-level self-test or an ASIC production test. Test routines 128 will generally include slightly differences for system-level tests or production tests. Processing core 110 controls signals BISTERROR, and BISTDONE to indicate test results.
[0028] FIGS. 2A and 2B are timing diagrams for signals BISTERROR and BISTDONE and respectively illustrate a passed self-test and a failed self-test in the exemplary embodiment of the invention.
[0029] In FIG. 2A , processing core 110 executes test code 128 (for production or system-level testing) in response to a reset of ASIC 100 . Processing core 110 begins by activating single BISTERROR for a short period (e.g., about 100 ns) to demonstrate that signal BISTERROR is functional. External test equipment (not shown) detects a failure if processing core 110 fails to activate signal BISTERROR within a period after activation of the reset signal. After deactivating signal BISTERROR, processing core 110 executes the portions of test routines 128 that input control signals such as signal ASICTEST designate. For the example of FIG. 2A , no error is detected, and processing core 110 activates signal BISTDONE upon completing execution of test routines 128 . External test equipment during production testing or system circuitry during in system testing identifies the passed self-test from the toggling of signal BISTERROR followed by the activation of signal BISTDONE while signal BISTERROR is in a state indicating no error (e.g., inactive).
[0030] In FIG. 2B , processing core 110 again toggles single BISTERROR to demonstrate signal BISTERROR is functional and then executes the portions of test routines 128 designated by the input control signals. For the example of FIG. 2B , execution of test routines 128 detects a failure, and processing core 110 reactivates signal BISTERROR and then activates signal BISTDONE to indicate the detection of a test failure. External test equipment or system circuitry identifies the failed self-test from activation of signal BISTDONE while signal BISTERROR is in a state indicating an error (e.g., active). Processing core 100 further can use other output signals from GPIO interface 130 to indicate the type and/or location of the defect or failure.
[0031] In the exemplary embodiment of the invention, test routines 128 are part of the boot code that ASIC 100 executes during power up, and test routines 128 include three main portions referred to herein as BIST, EEPROM, and self-test. In the exemplary embodiment of the invention, a control signal input via GPIO interface 130 controls whether processing core 110 executes test routines 128 or attempts to download firmware from external memory via interface 130 or 150 . If test routines 128 are executed, processing core 110 starts with the BIST portion of test routines 128 .
[0032] The BIST portion is executed before the system is setup to use internal memory or the internal operating system of ASIC 100 . The BIST portion tests internal DRAM 122 and SRAM 124 , e.g., by performing extensive write and read patterns and validating whether the data read is correct. Processing core 110 checks an error code resulting from the internal memory test and activates signal BISTERROR and then BISTDONE if an error is detected. If ASIC 100 passes the BIST test, test routines 128 enable use of a memory controller in interface 150 to download firmware from an external device.
[0033] In one embodiment of the invention, the BIST test of internal memory is only performed for system-level self-tests and not for production tests. Production testing of ASICs including internal memory such as DRAM often must identify the location of any defects in the memory to enable conventional laser repair operations. To identify the location of a defect in a memory array, the simple error signal timing illustrated in FIGS. 2A and 2B can be augmented to provide additional output signals indicating the exact location of any reparable defect in a memory array. However, the resulting increase in the complexity of output of the errors signals increases the complexity of test routines 128 so that a conventional memory array test method may be suited for production testing. For a system-level test, repair is generally not an option, and the memory testing that test routines 128 provides all the required information. As noted above, in the exemplary embodiment, the signal ASICTEST is activated or not to indicate whether a BIST of internal memory is required.
[0034] After ASIC 100 passes the test in the BIST portion of test routines 128 , processing core 110 executes the EEPROM portion of test routines 128 . FIG. 3 is a flow diagram of a process 300 implemented in the EEPROM portion. Process 300 in an initial decision step 310 checks a control signal input via GPIO interface 130 (e.g., a pin GPIO[ 13 ]). If the control signal is not activated, processing core 110 executes of the self-test portion 370 of test routines 128 .
[0035] If the control signal is activated, processing core 110 in step 320 attempts to reset an external memory such as an external serial EEPROM and then jumps to executing self-test routines 370 if the reset operation failed (e.g., because no external memory is connected). If the reset operation is successful, processing core 110 in step 340 reads or checks identifying data that should be stored in the external memory and then in a decision step 350 determines whether the external memory contains expected information, e.g., the first word has a value not equal xFFFF. If the external memory contains the expected information, processing core 110 in step 350 downloads firmware to internal memory 120 and executes that firmware, instead of continuing execution of test routines 128 . If the external memory does not provide the expected information, processing core 110 jumps from decision step 350 to execute the self-test portion 370 of test routines 128 .
[0036] The ability to load firmware from external memory during the boot process facilitates implementation of tests that are specialized for debugging the design of ASIC 100 or specialized for the particular system using ASIC 100 . A co-owned U.S. patent application entitled, “Point-Of-Sale Demonstration of Computer Peripherals”, describes use of the firmware download capability to implement non-testing functions (e.g., providing a system demonstration) and is hereby incorporated by reference in its entirety.
[0037] The self—test portion of test routines 128 verifies the operation of the major blocks within ASIC 100 . In particular, in the exemplary embodiment, the self-test portion of test routines 128 tests interface 150 , DMA block 170 , and codec 140 . Additional testing of internal memory 120 can also be performed.
[0038] The specific tests of particular blocks depend on the specific functions of the block. For example, for codec 140 , processing core 110 can direct data form internal memory 120 to codec 140 for coding or decoding. Processing core 110 then determines whether the output data from codec 140 matches correctly coded or decoded data that is stored in ROM 126 .
[0039] To provide tests that replicate actual system operation, test routines can try to emulate the normal data flow in ASIC 100 . For example, a normal data flow in the exemplary embodiment starts with input of data to an input FIFO buffer in USB interface 150 . The input FIFO buffer can include a normal input path from external circuits and an alternative input path that allows processing core 110 to write data into the input FIFO buffer to start a data flow. Similarly, processing core 110 can read data in an output buffer to check data output.
[0040] A data flow can proceed from the input FIFO buffer to internal memory 120 , from internal memory 120 to codec 140 for coding, back to internal memory 120 , from internal memory 120 to codec 140 for decoding or to DMA block 170 . The proper passage of data through the entire system provides a high degree of verification of the operation of ASIC 100 . Additionally, testing a data flow through several functional blocks may avoid the need to separately test each data transfer step because processing core 110 can observe the data at the final stage of the flow to detect errors. To further facilitate error checking, the last functional block in the data flow, e.g., DMA block 170 can include a CRC code calculator, so that processing core 110 only needs to check a CRC code instead of the entire output data stream.
[0041] Although the functional blocks of ASIC 100 can be conventional in implementation, specific features can be built into various functional block to facilitate test operations executed embedded processor 110 . For example, the DMA block 170 can include circuitry that performs the CRC calculations to allow error detection without requiring processing core 110 to monitor the entire data stream. Input blocks such as USB interface 150 can provide paths that permit processing core 110 to write input values into incoming FIFO buffers to simulate data input when testing a data flow. Implementations of “loopback test” capabilities in the functional block can facilitate tests executed by processing core 110 . Such tests would be particularly useful for testing on-chip network interfaces.
[0042] Processing core 110 can also test data flow through the blocks of ASIC 100 at specific clock speeds used in ASIC 100 and determine whether the blocks are meeting the required timing. For this testing, the clock and reset pins of ASIC 100 can driven during production or system-level testing in the manner required for normal operation of ASIC 100 . Conventional test equipment 400 as illustrated in FIG. 4 can easily implement the timing signal CLK and control signals ASICTEST to test ASIC at full speed or at an elevated speed, for example, to prove timing margins during production testing.
[0043] In the above test process, processing core 110 can provide a failure code CODE in addition to asserting signal BISTERROR. Failure code CODE would indicate the nature or the location of the failure found during testing. For example, the value a 2-bit failure code can designate that whether the detected failure is in internal memory 120 , codec 140 , DMA block 170 , or interface block 150 .
[0044] In a product, ASIC 100 is connected to other system components 500 such as illustrated in FIG. 5 . In the embodiment of FIG. 5 , for example, external interface 150 is connected to a host connector 510 for connection to a host computer or external memory, and print engine communications 160 connects to a printer connector 520 of a printer. Clock and system control circuit 540 and an optional external memory 530 connect to timing circuits 180 and GPIO interface 130 . For system-level testing, system control 540 controls signal ASICTEST to select a system-level test and monitors signals BISTDONE and BISTERROR to determine whether ASIC 100 is functioning properly. In a system such as illustrated in FIG. 5 , when executing test routines, which may be from internal memory 120 or downloaded to ASIC 100 from memory 530 , processing core 110 can test ASIC 100 and any of the other system components 500 .
[0045] FIG. 6 illustrates a flow diagram of a method 600 for testing an integrated circuit. The method 600 includes, at 604 , applying a control signal (e.g., signal ASICTEST of FIG. 1 ) to an integrated circuit (e.g., integrated circuit ASIC 100 of FIG. 1 ). The method 600 further includes, at 608 , selecting test routines according to the applied control signal. The selected test routines are used for a production test or a system-level test of the integrated circuit, as previously discussed. For example, when the control signal has a first state, selected test routines implement a production test of the integrated circuit using a processing core of the integrated circuit; and when the control signal has a second state, selected test routines implement a system-level test of the integrated circuit. The method 600 further includes, at 612 , observing a first signal output from the integrated circuit as a result of the processing core executing the selected test routines, the first signal indicating whether the execution of the test routines detected a failure in the integrated circuit.
[0046] Although the invention has been described with reference to particular embodiments, the description is only an example of the invention's application and should not be taken as a limitation. For example, although the above-described embodiment is a formatter for a printer, embodiments of the invention can be employed in other types of integrated circuits. Various other adaptations and combinations of features of the embodiments disclosed are within the scope of the invention as defined by the following claims. | A test method for an ASIC uses an embedded processor in the ASIC to execute test routines from an embedded memory or an external memory. During ASIC production, the test routines can comprehensively test of the blocks of the ASIC without a complicated test pattern from test equipment. The test routines can also perform power-up tests in systems or end products containing the ASIC. Test selection, activation, and result output can be implemented using a few terminals of the ASIC. | 6 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is related to the concurrently filed applications listed below, the contents of which are incorporated herein by reference in their entirety.
[0000]
Application
Attorney
No.
Filing Date
Title
Docket No.
Unknown
Jan. 18, 2008
METHOD OF CONSTANT
SNTEC.001AUS
AIRFLOW CONTROL FOR A
VENTILATION SYSTEM
Unknown
Jan. 18, 2008
METHOD OF CONSTANT RPM
SNTEC.001AUS2
CONTROL FOR A VENTILATION
SYSTEM
Unknown
Jan. 18, 2008
METHOD OF TRANSITION
SNTEC.001AUS3
BETWEEN CONTROLS FOR A
VENTILATION SYSTEM
Unknown
Jan. 18, 2008
MULTI-LEVEL PROGRAMMING
SNTEC.001AUS4
OF MOTOR FOR A VENTILATION
SYSTEM
Unknown
Jan. 18, 2008
MOTOR CONTROL APPARATUS
SNTEC.001AUS6
FOR A VENTILATION SYSTEM
BAGROUND
[0002] The present disclosure relates to airflow control, and more particularly, to control of an electric motor for a substantially constant airflow.
Discussion of Related Technology
[0003] A typical ventilation system includes a fan blowing air and a ventilation duct to guide the air from the fan to a room or space to air condition. An electric motor is coupled to the fan and rotates the fan. Certain ventilation systems also include a controller or control circuit for controlling operation of the electric motor for adjusting the rotational speed of the motor. The controller may change the electric current supplied to the electric motor to adjust the rotational speed. In certain ventilation systems, the controller controls the operation of the motor to adjust the air flow rate, which is the volume of the air flowing through the duct for a given time period.
SUMMARY
[0004] One aspect of the invention provides a method of operating an electric motor in a ventilation system. The method may comprise: detecting an electric current applied to a motor; detecting a rotational speed of the motor; and controlling the motor's operation to adjust a product of the electric current and the rotational speed so as to arrive a target value.
[0005] In the foregoing method, the motor is coupled with a fan, which blows air in a ventilation duct, wherein controlling the motor's operation may generate an airflow with a substantially constant airflow rate in the ventilation duct in a range of a static pressure within the duct. The system may not comprise an airflow rate sensor for detecting an airflow rate generated by the blower, wherein controlling the motor's operation does not use an input of an airflow rate change. Controlling the motor's operation may generate the substantially constant airflow rate while the static pressure significantly changes. The system may not comprise a static pressure sensor for detecting the static pressure within the duct, wherein controlling the motor's operation does not use an input of a static pressure change.
[0006] Still in the foregoing method, controlling the motor's operation may comprise adjusting a turn-on period of the motor so as to attempt to make the product reach the target value. The target value may be computed using a rated electric current and a rated rotational speed of the motor. The target value may be a fractional value of a product of a rated electric current and a rated rotational speed of the motor. The method may further comprise: receiving a user input of a desired level of airflow rate; and obtaining the target value that corresponds to the desired level. Receiving the user input may comprise receiving a user's selection among a plurality of predetermined levels, and wherein obtaining the target value may comprise retrieving the target value from a plurality of values stored in a memory, wherein the retrieved target value may be associated with the user's selection. Receiving the user input may comprise receiving a user's desired level represented in a number, and wherein obtaining the target value may comprise computing the target value using the number and a preprogrammed formula.
[0007] Still in the foregoing method, controlling the motor's operation may comprise transitioning from adjusting the product to adjusting a rotational speed of the motor to arrive another target value. Controlling the motor's operation may comprise transitioning to adjusting the product from adjusting a rotational speed of the motor to arrive another target value. The method may further comprise: determining whether the electric current is greater or smaller than a reference value; and when the electric current is greater than the reference value, continuing to control the motor's operation so as to adjusting the product. The method may further comprise: determining whether the electric current is greater or smaller than a reference value; and when the electric current becomes smaller than the reference value, controlling the motor's operation so as to transition from adjusting the product to adjusting a rotational speed of the motor to arrive another target value.
[0008] Another aspect of the invention provides a method of operating an electric motor in a ventilation system. The method comprises: providing a blower comprising a motor and a fan coupled to the motor, the blower being configured to generate an airflow in a ventilation duct; detecting an electric current applied to the motor; detecting a rotational speed of the motor; and controlling the motor's operation so as to generate the airflow with a substantially constant airflow while a static pressure within the duct substantially changes, wherein controlling the motor's operation does not use an input of a static pressure within the duct.
[0009] In the foregoing method, the system may not comprise a static pressure sensor for detecting a static pressure within the duct. The system may not comprise an airflow rate sensor for detecting an airflow rate generated by the blower, wherein controlling the motor's operation does not use an input of an airflow rate generated by the blower. Controlling the motor's operation may comprise conducting a feedback control of a product of the electric current and the rotational speed so as to make the product reach a target value. Controlling the motor's operation may comprise conducting a feedback control of the rotational speed so as to make the rotational speed reach a target value. Controlling the motor's operation may comprise conducting a feedback control of a product of the electric current and the rotational speed so as to make the product reach a target value.
[0010] The method may further comprise determining whether the electric current is greater or smaller than a reference value, wherein the feedback control of the product is performed when the electric current is greater than the reference value. Controlling the motor's operation may comprise a feedback control of the rotational speed so as to make the rotational speed reach a target value. The method may further comprise determining whether the electric current is greater or smaller than a reference value, wherein the feedback control of the rotational speed is performed when the electric current is smaller than the reference value.
[0011] Another aspect of the invention provides a method of operating an electric motor in a ventilation system. The method comprises: providing a blower comprising a motor and a fan coupled to the motor, the blower being configured to generate an airflow in a ventilation duct; monitoring a rotational speed of the motor; monitoring an electric current applied to a motor; and controlling the motor's operation so as to maintain the rotational speed within proximity of a target rotational speed while the electric current is smaller than a reference value.
[0012] In the foregoing method, controlling the motor's operation may generate a substantially constant airflow rate while a static pressure within the duct significantly changes. The system may not comprise an airflow rate sensor for detecting an airflow rate generated by the blower, wherein controlling the motor's operation does not use an input of an airflow rate generated by the blower. The system may not comprise a static pressure sensor for detecting the static pressure within the duct, wherein controlling the motor's operation does not use an input of a static pressure within the duct. Controlling the motor's operation may comprise adjusting a turn-on period of the motor so as to attempt to make the product reach the target rotational speed. The method may further comprise receiving a user's input of a desired rotational speed, which becomes the target rotational speed. The target rotational speed may be a fractional value of a rated rotational speed of the motor.
[0013] The foregoing method may further comprise: receiving a user input of a desired level of the rotational speed, wherein the user input may comprise a selection among a plurality of predetermined levels; and retrieving, from a memory, the target rotational speed associated with the user's selection. The method may further comprise: receiving a user input of a desired level of the rotational speed, wherein the user inputs the desired level represented in a number; and computing the target rotational speed using the number and a preprogrammed formula. The target rotational speed may be computed using the number and a rated rotational speed of the motor. Controlling the motor's operation may comprise transitioning from maintaining the rotational speed to maintaining a product of the electric current and the rotational speed within proximity of another target value. The other target value may be computed using a rated electric current and a rated rotational speed of the motor. Transitioning may occur when the electric current becomes greater than the reference value.
[0014] Another aspect of the invention provides a method of operating an electric motor in a ventilation system. The method comprising: providing a blower comprising a motor and a fan coupled to the motor, the blower being configured to generate an airflow in a ventilation duct; detecting an electric current applied to the motor; detecting a rotational speed of the motor; and controlling the motor's operation so as to generate the airflow with a substantially constant airflow while a static pressure within the duct substantially changes, wherein controlling the motor's operation does not use an input of an airflow rate generated by the blower.
[0015] The system may not comprise an airflow rate sensor for detecting changes of the airflow rate. The system may not comprise a static pressure sensor for detecting a static pressure within the duct, and wherein controlling the motor's operation does not use an input of a static pressure within the duct. Controlling the motor's operation may comprise a feedback control of the rotational speed so as to make the rotational speed reach a target value. Controlling the motor's operation may comprise a feedback control of a product of the electric current and the rotational speed so as to make the product reach a target value. The method may further comprise determining whether the electric current is greater or smaller than a reference value, wherein the feedback control of the product is performed when the electric current is greater than the reference value. Controlling the motor's operation may comprise a feedback control of the rotational speed so as to make the rotational speed reach a target value. The method may further comprise determining whether the electric current is greater or smaller than a reference value, wherein the feedback control of the rotational speed is performed when the electric current is smaller than the reference value.
[0016] Another aspect of the invention provides a method of operating an electric motor in a ventilation system. The method comprising: running a motor in a first control mode, which attempts to make a I·RPM value reach a first target value, wherein the I·RPM value is a product of an electric current and the rotational speed of the motor; running the motor in a second control mode, which attempts to make the rotational speed reach a second target value; and transitioning between the first control mode and the second control mode.
[0017] The foregoing method may further comprise: comparing the electric current with a reference value; and wherein transitioning may be carried out based on a result of the comparison. Comparing may be continuously, periodically or sporadically performed during running of the motor. The reference value may be a user's input or a value computed using a user's input for at least one of the first and second control modes. The method may further comprise receiving a user input of a desired level of airflow. The desired level may be a fractional value of a maximum airflow rate, and wherein the reference value may be computed using the fractional value. The reference value may be a product of the fractional value and a rated electric current of the motor. The first target value may not change while running in the first control mode, and wherein the second target value may not change while running in the second control mode. The first control mode may be chosen when the electric current is greater than the reference value. The second control mode may be chosen when the electric current is smaller than the reference value. The motor may run in the first control mode at a first static pressure within a ventilation duct, wherein the motor may run in the second control mode at a second static pressure, which may be greater than the first static pressure.
[0018] The foregoing method may further comprise: receiving a user's input of a desired level of airflow, wherein the user selects one of a plurality of predetermined levels of airflow; and retrieving the first target value from a plurality of values stored in a memory of the system, wherein the retrieved first target value may be associated with the user's selection. The method may further comprise: receiving a user's input of a desired level of airflow, wherein the user inputs the desired level represented in a number rather than selecting from preprogrammed choices; and computing the first target value using the number and a preprogrammed formula. The first target value may be computed using a rated electric current and a rated rotational speed of the motor. The method may further comprise receiving a user's input of a desired maximum rotational speed, which becomes the second target value for the second control mode
[0019] The motor may be coupled with a fan, which blows air in a ventilation duct, wherein running the motor in the first control mode may generate an airflow with a substantially constant airflow rate while a static pressure within the duct significantly changes. The motor may be coupled with a fan, which blows air in a ventilation duct, wherein the system may not comprise an airflow rate sensor for detecting an airflow rate generated by the fan, wherein running the motor in the first or second control mode does not use an input of an airflow rate generated by the fan. The motor may be coupled with a fan, which blows air in a ventilation duct, wherein the system may not comprise a static pressure sensor for detecting a static pressure within a ventilation duct, wherein running the motor in the first or second control mode does not use an input of a static pressure within the ventilation duct. Running the motor in at least one of the first and second control nodes may comprise adjusting a turn-on period of the motor so as to make the product reach the first target value. The method may further comprise: monitoring the electric current applied to the motor; and monitoring a rotational speed of the motor.
[0020] Another aspect of the invention provides a method of operating an electric motor in a ventilation system. The method comprising: running a motor in a first control mode, which attempts to make a I·RPM value reach a first target value, wherein the I·RPM value may be a product of an electric current and the rotational speed of the motor; monitoring changes of the electric current; comparing the monitored electric current against a reference; and transitioning the motor's operation to a second control mode, which attempts to make the rotational speed reach a second target value, when determining that the electric current changes from a value greater than the reference to a value smaller than the reference.
[0021] A further aspect of the invention provides a method of operating an electric motor in a ventilation system. The method comprising: running a motor in a second control mode, which attempts to make a rotational speed of the motor reach a second target value; monitoring changes of the electric current; comparing the monitored electric current against a reference; transitioning the motor's operation to a first control mode, which attempts to make the a I·RPM value reach a first target value, when determining that the electric current changes from a value smaller than the reference to a value greater than the reference, wherein the I·RPM value may be a product of an electric current and the rotational speed of the motor.
[0022] A further aspect of the invention provides a method of operating an electric motor in a ventilation system the method comprising: providing a user interface configured to receive a user's input; receiving a user's input of a desired level of airflow rate, wherein the desired level may be a fraction of a maximum airflow rate computed using at least one rated value of the motor; obtaining a target value corresponding to the desired level for a feedback control; and conducting the feedback control using the target value for a substantially constant airflow rate.
[0023] In the foregoing method, receiving the user input may comprise receiving a user's selection among a plurality of predetermined levels. Obtaining the target value may comprise retrieving the target value from a plurality of values stored in a memory, wherein the retrieved target value may be associated with the user's selection. The desired level may be a user inputted number rather than a selection among preprogrammed choices. Obtaining the target value may comprise computing the target value using the number and a preprogrammed formula. The feedback control may be to adjust a product of an electric current and a rotational speed so as to make the product stay within proximity of the target value. The feedback control may be conducted when an electric current applied to the motor is greater than a reference value. The reference value may be the same fraction of a rated electric current of the motor. The maximum airflow rate may be a product of a rated electric current and a rated rotational speed.
[0024] The method may further comprise: receiving a user's input of a desired level of a rotational speed, which may be a fractional value of a rated rotational speed of the motor; and obtaining a target rotational speed corresponding to the desired level for another feedback control. The method may further comprise conducting the other feedback control using the target rotational speed to make a rotational speed of the motor stay within proximity of the target rotational speed. The other feedback control using the target rotational speed may generate a substantially constant airflow rate. The other feedback control may be conducted when an electric current applied to the motor may be smaller than a reference value.
[0025] The user input of a desired level may comprise a selection among a plurality of predetermined levels of rotational speed, and wherein obtaining the target rotational speed may comprise retrieving, from a memory, the target rotational speed associated with the user's selection. The user input of a desired level may comprise a user inputted number rather than a section among preprogrammed levels, and wherein obtaining the target rotational speed may comprise computing the target rotational speed using the number and a preprogrammed formula. The target rotational speed may be computed using the user inputted number and a rated rotational speed of the motor.
[0026] A still further aspect of the invention provides a method of operating an electric motor in a ventilation system. The method comprising: providing a user interface configured to receive a user's input; receiving a user's input of a desired level of a rotational speed, which may be a fractional value of a rated rotational speed of the motor; and obtaining a target rotational speed corresponding to the desired level for a feedback control; and conducting the feedback control using the target rotational speed for a substantially constant airflow rate in a range of an electric current, which may be smaller than a reference value.
[0027] The method may further comprise receiving a user's input of a desired level of airflow rate, wherein the desired level may be a fraction of a maximum airflow rate computed using at least one rated value of the motor. The reference value may be a product of the fraction and a rated electric current of the motor. Conducting the feedback control using the target rotational speed attempts to make a rotational speed of the motor stay within proximity of the target rotational speed. The user input of a desired level may comprise a selection among a plurality of predetermined levels of rotational speed, and wherein obtaining the target rotational speed may comprise retrieving, from a memory, the target rotational speed associated with the user's selection. The user input of a desired level may comprise a user inputted number rather than a section among preprogrammed levels, and wherein obtaining the target rotational speed may comprise computing the target rotational speed using the number and a preprogrammed formula. The target rotational speed may be computed using the user inputted number and a rated rotational speed of the motor.
[0028] A still further aspect of the invention provides a method of controlling an electric motor for use in a ventilation system. The method comprising: providing a ventilation system comprising a blower and a duct with at least one opening, the blower comprising a motor and a fan coupled to the motor, the blower being configured to generate an airflow through the at least one opening; conducting a test operation of the blower for collecting data indicative of the motor's operation in the ventilation system; processing the data collected from the test operation to generate a correction coefficient; and conducting a feedback control using a target value, which has been modified using the correction coefficient.
[0029] In the foregoing method, the test operation may be conducted under a condition where a static pressure inside the duct may be substantially the minimum. The test operation may be conducted under a condition where the at least one opening may be substantially fully open. Conducting the test operation may comprise: running the motor; changing the rotational speed of the motor; and monitoring the electric current while changing the rotational speed. Changing the rotational speed may comprise gradually increasing or decreasing the rotational speed. The collected data may comprise a relationship between an electric current applied to the motor and the motor's rotational speed monitored during at least part of the test operation. Processing the data may comprise: computing values of the correction coefficient using an electric current and a rotational speed collected during at least part of the test operation; and associating each value of the correction coefficient with a volumetric airflow rate. The method may further comprise: storing the values of the correction coefficient and associated volumetric airflow rates in a memory.
[0030] Still in the foregoing method, the target value may be associated with a volumetric airflow rate and has been modified using the correction coefficient that may be associated with the same volumetric airflow rate. The target value for the feedback control would have been different unless modified using the correction coefficient. Conducting a feedback control may comprise a constant I·RPM control, which attempts to make a product of an electric current and a rotational speed within proximity of the target value. The target value of the feedback control may be a fraction of a product of a rated electric current and a rated rotational speed, which has been modified using the correction coefficient. The constant I·RPM control may be conducted in a range of electric current, which is greater than a reference current value. The reference current value may be a fractional value of a rated electric current of the motor.
[0031] Still in the foregoing method, conducting a feedback control may comprise: receiving a user input of a desired level of airflow rate; and computing the target value that corresponds to the desired level and may be modified based on the correction coefficient. Conducting a feedback control may comprise a constant RPM control, which attempts to make a rotational speed within proximity of the target value. The target value of the feedback control may be a fraction of a rated rotational speed of the motor, which has been modified using the correction coefficient. The method may further comprise receiving a user's input of a desired rotational speed, which becomes the target value. The correction coefficient may be to compensate at least some variations caused by the motor's unique relationship between an electric current applied to the motor and a rotational speed of the motor. The feedback control may generate a substantially constant airflow rate while a static pressure within the duct significantly changes. The system may not comprise an airflow rate sensor for detecting an airflow rate generated by the blower, wherein the feedback control does not use an input of an airflow rate generated by the blower. The system may not comprise a static pressure sensor for detecting the static pressure within the duct, wherein the feedback control does not use an input of a static pressure within the duct
[0032] A further aspect of the invention provides a motor control apparatus for a ventilation system. The apparatus comprises: an electric current sensor configured to detect an electric current applied to a motor; a speed sensor configured to detect a rotational speed of the motor; and a controller configured to conduct a feedback control of adjusting a product of the electric current and the rotational speed to stay within proximity of a target value.
[0033] In the foregoing apparatus, the controller may be further configured to compare the electric current against a reference value, and to conduct the feedback control when the electric current is greater than the reference value. The controller may be further configured to compare the electric current against a reference value, and to conduct another feedback control of adjusting the rotational speed stay within proximity of a second target value when the electric current is smaller than the reference value. The controller may be further configured to compare the electric current against a reference value, and to transition between a first control mode and a second control mode based on the comparison, wherein in the first control mode the controller may be configured to conduct the feedback control, wherein in the second control mode the controller may be configured to conduct another feedback control of adjusting the rotational speed stay within proximity of another target value.
[0034] The foregoing apparatus may further comprise at least one user input interface configured to receive a user's desired level of airflow rate and to further receive a user's desired level of rotational speed. The controller may be further configured to use the user's desired level of airflow rate for the feedback control and to use the user's desired level of rotational speed for another feedback control. At least one of the feedback control and the other feedback control may be designed to achieve a substantially constant airflow rate in different static pressure ranges.
[0035] The controller may be further configured to control the motor's operation so as to generate a substantially constant airflow rate from a fan coupled with the motor, wherein the controller may not require an input of the static pressure for the feedback control. The controller may be further configured to control the motor's operation so as to generate a substantially constant airflow rate from a fan coupled with the motor, wherein the controller may not require an input of the airflow rate generated by the fan for the feedback control. The controller may be further configured to conduct a test operation to collect a relationship between the electric current and the rotational speed, wherein the controller may be further configured to compute a correction coefficient using the collected relationship, wherein the controller may be further configured to modify a target value for a feedback control using the correction coefficient.
[0036] A further aspect of the invention provides a motor control apparatus for a ventilation system. The apparatus comprises: an electric current sensor configured to detect an electric current applied to a motor; a speed sensor configured to detect a rotational speed of the motor; and a controller configured to compare the electric current against a reference value, and to conduct a feedback control of adjusting the rotational speed stay within proximity of a second target value when the electric current may be smaller than the reference value.
[0037] A further aspect of the invention provides a motor control apparatus for a ventilation system. The apparatus comprises: an electric current sensor configured to detect an electric current applied to a motor; a speed sensor configured to detect a rotational speed of the motor; and a controller configured to compare the electric current against a reference value, and to transition between a first control mode and a second control mode based on the comparison, wherein in the first control mode the controller may be configured to adjust a product of the electric current and the rotational speed to stay within proximity of a first target value, wherein in the second control mode the controller may be configured to adjust the rotational speed stay within proximity of a second target value.
[0038] A further aspect of the invention provides a motor control apparatus for a ventilation system. The apparatus comprises: an electric current sensor configured to detect an electric current applied to a motor; a speed sensor configured to detect a rotational speed of the motor; at least one user input interface configured to receive a user's desired level of airflow rate and to further receive a user's desired level of rotational speed; and a controller configured to use the user's desired level of airflow rate for a first control mode and to use the user's desired level of rotational speed for a second control mode.
[0039] A further aspect of the invention provides a motor control apparatus for a ventilation system. The apparatus comprises: an electric current sensor configured to detect an electric current applied to a motor; a speed sensor configured to detect a rotational speed of the motor; and a controller configured to control the motor's operation so as to generate a substantially constant airflow rate from a fan coupled with the motor, wherein the controller may be configured to accomplish the substantially constant airflow rate over a significant range of a static pressure in a duct in which the blower may be installed without an input of the static pressure. The system may not comprise a static pressure sensor for detecting the static pressure in the duct.
[0040] A further aspect of the invention provides a motor control apparatus for a ventilation system. The apparatus comprises: an electric current sensor configured to detect an electric current applied to a motor; a speed sensor configured to detect a rotational speed of the motor; and a controller configured to control the motor's operation so as to generate a substantially constant airflow rate from a fan coupled with the motor, wherein the controller may be configured to accomplish the substantially constant airflow rate over a significant range of a static pressure in a duct in which the blower may be installed without an input of the airflow rate generated by the fan. The system may not comprise an airflow rate sensor for detecting the airflow rate generated by the fan.
[0041] A further aspect of the invention provides a motor control apparatus for a ventilation system. The apparatus comprises: an electric current sensor configured to detect an electric current applied to a motor; a speed sensor configured to detect a rotational speed of the motor; and a controller configured to conduct a test operation to collect a relationship between the electric current and the rotational speed, wherein the controller may be further configured to compute a correction coefficient using the collected relationship, wherein the controller may be further configured to modify a target value for a feedback control using the correction coefficient.
[0042] In the foregoing apparatus, the controller may be further configured to gradually change the rotational speed of the motor and monitor the electric current to collect the relationship. The controller may be further configured to generate values of the correction coefficient for various airflow rates. The controller may be configured to modify the target value at a given airflow rate using a value of the correction coefficient corresponding to the given airflow rate.
BRIEF DESCRIPTION OF THE DRAWINGS
[0043] The accompanying drawings include:
[0044] FIG. 1 illustrates a constant airflow operation and a non-constant airflow operation in a ventilation system while static pressure inside a duct changes;
[0045] FIG. 2 illustrates a typical relationship between static pressure and motor's speed (RPM) in a constant airflow operation;
[0046] FIG. 3 is a block diagram of a motor control system according to one embodiment;
[0047] FIG. 4 is a flow chart for a constant I·RPM motor control operation according to one embodiment;
[0048] FIG. 5 illustrates a RPM-static pressure profile in a motor control operation according to one embodiment;
[0049] FIG. 6 is a flowchart of a motor control operation including a transition between a constant I·RPM control and constant RPM control according to one embodiment;
[0050] FIG. 7 illustrates an RPM-static pressure relationship in multi-level airflow controls according to one embodiment;
[0051] FIG. 8 illustrates a static pressure-airflow rate relationship in multi-level airflow controls according to one embodiment;
[0052] FIG. 9 is a flowchart for a test operation and a modified constant airflow control using data from the test operation according to one embodiment;
[0053] FIG. 10 illustrates a current-RPM characteristic of a motor acquired in a test operation according to one embodiment;
[0054] FIG. 11 illustrates a Kr-RPM relationship of a motor according to one embodiment;
[0055] FIG. 12 illustrates an RPM-airflow rate relationship in a steady state operation of a motor when the static pressure remains constant according to one embodiment;
[0056] FIG. 13 illustrates a Kr-airflow rate relationship of a motor according to one embodiment;
[0057] FIG. 14 is a detailed block diagram of a motor controller for a ventilation system according to one embodiment;
[0058] FIG. 15 is a circuit diagram of the motor controller of FIG. 14 ;
[0059] FIG. 16 is a circuit diagram of a speed control interface circuit shown in FIG. 14 ; and
[0060] FIGS. 17A and 17B illustrate a PWM input signal and a conversed PWM signal for use in a motor speed control according to one embodiment.
DETAILED DESCRIPTION OF EMBODIMENTS
[0061] Various embodiments of the invention will be discussed in more detail below, with reference to the drawings. The sizes and shapes of elements shown in the drawings do not represent actual sizes or shapes, nor represent relative sizes of the elements shown in a single drawing.
Static Pressure Changes in a Ventilation System
[0062] As discussed above in the Background section, a ventilation system typically includes a motor, a fan coupled to the motor and a ventilation duct to guide air blown by the fan. The pressure inside the ventilation duct (static pressure) changes for many reasons. The static pressure inside the duct changes, for example, when an object is placed inside the duct or in front of an opening of the duct. Dust accumulated within the duct or in a filter installed in the duct can increase the static pressure inside the duct. The static pressure changes make the airflow control difficult. In particular, the static pressure changes in the duct influence the operation of the motor.
Motor Controller
[0063] In embodiments, a motor control circuit or controller controls operation of the motor for adjusting the air flow rate in a ventilation system. More specifically, the controller controls the operation of the motor to generate a substantially constant airflow rate in the duct. In one embodiment, the controller controls the motor operation to generate a substantially constant airflow rate over static pressure changes in the duct of the ventilation system. The controller may not require a static pressure sensor for monitoring the static pressure changes or a feedback control based on a monitored static pressure input. Also, the controller may not require an airflow rate sensor for monitoring the airflow rate changes or a feedback control based on a monitored airflow rate input. In some embodiments the controller are imbedded in the motor, and in others the controller is separate from the motor.
[0064] In one embodiment, the controller or its associated sensor monitors the rotational speed (e.g., RPM) of the motor and utilizes the monitored speed for the control of the airflow rate. In one embodiment, the controller or its associated sensor monitors the electric current applied to the motor and utilizes the monitored electric current for the control of the airflow rate. As will be discussed in detail, in one embodiment, the controller processes the rotational speed input and the electric current input so as to determine the length of time during which the power is turned on (i.e., turn-on period) to accomplish a substantially constant airflow. In this embodiment, the controller controls the airflow rate using intrinsic information of the motor's operation, such as rotational speed and electric current, rather than using extrinsic information such as static pressure and airflow rate.
Substantially Constant Airflow
[0065] FIG. 1 plots changes of the airflow rate (volume/time) over changes of static pressure in a ventilation duct. Line 20 represents a constant airflow control of the motor operation according to an embodiment of the invention. Line 22 represents non-controlled operation of a motor, in which the airflow rate decreases as the static pressure increases. In the constant airflow control line 20 , the airflow rate, e.g., in CFM (cubic feet per minute) stays substantially constant over significant changes in the static pressure. In other words, the airflow rate remains within a range between a lower limit QL and a higher limit QH regardless the change of the static pressure.
[0066] According to embodiments of the invention, the controller attempts to control the motor's operation such that the airflow rate changes like the constant airflow control line 20 at least for a static pressure range. As a result when the motor operates under the constant airflow control, the airflow rate stays substantially constant for at least part of the span of static pressure changes or throughout the span of the static pressure changes.
[0067] Here, a substantially constant airflow means that the airflow rate remains within a range as the static pressure changes. According to various embodiments, the range for a substantially constant airflow rate can be about 2, 4, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28 or 30 percent of the total range in which the airflow rate can change when there is no airflow control. Alternatively, the range for a substantially constant airflow rate can be about 1, 3, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27 or 29 percent of the range of the airflow rates between 0 CFM and the maximum airflow rate the motor can generate in a given ventilation system.
[0068] Alternatively, a substantially constant airflow means that the airflow rate is within proximity of a target value as the static pressure changes. According to various embodiments, the airflow rate is within proximity of a target value when the airflow rate is within about 2, 4, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28 or 30 percent of the total span of the airflow rate. Alternatively, “within proximity” is accomplished when the airflow rate is within about 1, 3, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27 or 29 percent of the range of the airflow rates between 0 CFM and the maximum airflow rate the motor can generate in a given ventilation system.
[0069] FIG. 2 illustrates a typical relationship between a motor's RPM and the static pressure changes in a duct when substantially constant airflow is accomplished and maintained throughout the static pressure range. In the static pressure range 25 a between the minimum static pressure and a midpoint 25 c , the motor's RPM changes significantly as the static pressure changes. On the other hand, the static pressure range 25 b between the midpoint 25 c and the minimum static pressure, the motor's RPM changes significantly less than in the range 25 a as the static pressure changes. In one embodiment, the controller uses the motor's RPM and the electric currently applied to the motor to control the motor operation and emulate the relationship illustrated in FIG. 2 .
Constant Airflow Control
[0070] In a ventilation system having an outlet with a variable opening area, an airflow rate (Q) can be represented by Formula 1 below, in which “A” denotes the open area of the outlet and “V” denotes the speed of the air passing the outlet.
[0000] Q=A×V (1)
[0071] The open area (A) of the outlet has a generally direct relationship with a load applied to the motor. As the open area (A) of the outlet increases, the load applied to the motor generally proportionally increases. Assuming all other conditions remain the same, an increase of the load increases the electric current (I) applied to the motor. Thus, the open area (A) of the outlet and the electric current (I) applied to the motor have the general relationship of Formula 2.
[0000] I∝A (2)
[0072] The speed of air (V) passing the outlet opening is generally proportional to the motor's rotational speed (e.g., RPM), assuming all other conditions remain the same. Thus, the motor's RPM and the speed (V) of air have the general relationship of Formula 3.
[0000] RPM∝V (3)
[0073] In view of the foregoing relationships, the airflow rate (Q) of a ventilation system can be represented using the electric current (I) and the motor's speed (RPM) as in Formula 4, in which “a” is a constant coefficient.
[0000] Q=α·I· RPM (4)
[0074] As noted above, a constant airflow control is to maintain the airflow rate (Q) constant or substantially constant. Thus, in theory, the constant airflow control can be accomplished by maintaining the product of the electric current (I) and the motor's speed (RPM) to stay constant while running the motor. This relationship is represented in Formula 5.
[0000] I· RPM=constant (5)
[0075] The relationship of Formula 5 is used in some embodiments of the invention. The foregoing discussion to reach Formula 5 provides some scientific and practical relationship among the variables (Q, A, V, RPM and I) in the ventilation system. However, their representations may not be exact in actual ventilation systems. As such, the present invention and its embodiments are not bound by any theory, even including the foregoing discussion to arrive in Formula 5.
Constant I·R Control
[0076] According to various embodiments, a motor control system controls the operation of the motor such that the I·RPM value remains constant or substantially constant. Here, a substantially constant I·RPM means that the product of the electric current and the motor's speed remains within a range as the static pressure changes. The range for a substantially constant I·RPM can be about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 percent of the total range in which the motor's I·RPM can change. Optionally the range is about 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5 or 6 of the total I·RPM range. Alternatively, the I·RPM range can be about 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 percent of the product of the rated speed (RPM 0 ) and rated current (I 0 ) of the motor. Optionally the range is about 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5 or 6 percent of the product (I 0 ·RPM 0 ).
[0077] In certain embodiments, the motor control system conducts a feedback control of the motor operation. In one embodiment, the feedback control attempts to make the I·RPM value reach a target value. During the feedback control, the I·RPM value changes in the vicinity of the target value. In another embodiment, the feedback control makes the I·RPM value stay within proximity of a target value. Here, the I·RPM value is in the vicinity or within proximity of a target value when the I·RPM value at a given time is apart from the target value by less then about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 percent of the total range in which the motor's I·RPM can change. Optionally the proximity range is less than about 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5 or 6 of the total I·RPM range. Alternatively, the I·RPM value is within proximity of a target value range when the I·RPM value at a given time is apart from the target value by less then about 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 percent of the product of the rated speed (RPM 0 ) and rated current (I 0 ) of the motor. Optionally the proximity range is less than about 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5 or 6 percent of the product (I 0 ·RPM 0 ).
[0078] To implement this control, referring to FIG. 3 , the motor control system includes a current sensor 301 , a speed sensor 303 , a controller 305 and a motor 307 . The current sensor 301 detects and monitors the electric current (I) applied to the motor 307 . Also, the speed sensor 303 detects and monitors the rotational speed (RPM) of the motor 307 . These sensors 301 , 303 and/or the controller 305 can be implemented within the motor housing or outside.
[0079] FIG. 4 is a flow chart for the motor control operation in accordance with one embodiment. In step 401 , the controller 305 receives the electric current (I) and the motor speed (RPM) from the current sensor 301 and speed sensor 303 . In one embodiment, the electric current (I) and the motor speed (RPM) are tagged with the time of sensing. For this purpose, in one embodiment, the current sensor 301 and speed sensor 303 are synchronized. In one embodiment, the electric current (I) and the motor speed (RPM) are substantially continuously supplied to the controller 305 . In one embodiment, the electric current (I) and the motor speed (RPM) are supplied to the controller 305 periodically or sporadically.
[0080] Then, the controller 305 processes the inputs and generates a control signal to control the motor's operation. In step 403 , the controller 305 calculates the I·RPM value by multiplying the inputted electric current (I) and the motor speed (RPM) that are detected at the same time. IN the alternative, the controller 305 may obtain an equivalent value of the I·RPM value (e.g., I·RPM value multiplied by a coefficient). Following, in step 405 , the controller 305 compares the resulting value against a target constant value for the constant airflow control so as to obtain a difference between them. In one embodiment, the target constant value is predetermined or preprogrammed. In another embodiment, the target constant value is chosen during the operation using the I·RPM values of earlier time of the same operation.
[0081] Subsequently in step 407 , the controller 305 generates a control signal to compensate the difference obtained in the previous step. In one embodiment, the control signal specifies the length of period during which the electric current is applied to the motor, i.e., the power is on. To compensate varying values of the difference, the controller 305 changes the length of period, which in turn changes the speed of the motor. The length of the period has generally proportional relationship with the speed of the motor. Thus, when the controller 305 generates a control signal specifying a longer period, the speed of the motor increases, vice versa. In one embodiment, the length of period is represented in a pulse width using a pulse width modulation (PWM). In another embodiment, the controller uses a method other than the PWM. Also, in other embodiments, the control signal specifies one or more other variables to compensate the electric difference obtained in the previous step.
[0082] The foregoing control for a constant I·RPM value can provide a substantially constant airflow through the ventilation outlet. The substantially constant airflow can be obtained throughout the span of the static pressure or in at least only part of the span of the static pressure. The relationship between the motor's RPM and static pressure from this constant I·RPM control is similar to the profile of FIG. 2 in at least part of the static pressure span. Thus, using the constant I·RPM control, a substantially constant airflow can be achieved over the changes of the static pressure.
[0083] In the discussed embodiments, the constant airflow control is performed over a range of static pressure changes without the need of a static pressure sensor for monitoring the static pressure and without a feedback control using an input of static pressure. Further, the constant airflow control is performed over a range of static pressure changes without the need of an airflow rate sensor for monitoring the airflow rate in the duct or outlet and further without a feedback control using an input of airflow rate.
[0084] In certain conditions, the constant I·RPM control provides a better result in some static pressure ranges than others. Thus, while in some embodiment, the constant I·RPM control is used throughout the static pressure range; in other embodiment, the constant I·RPM control only in a certain static pressure range. In one embodiment, the constant I·RPM control is used in a lower static pressure range as in the range 25 a of FIG. 2 , which generally corresponds to a higher electric current.
[0085] In one embodiment, the constant I·RPM control is used when the electric current is higher than a value, which is predetermined or chosen during the operation. In another embodiment, the constant I·RPM control is used when the electric current is within a range. In another embodiment, the constant I·RPM control is used in a higher static pressure range as in the range 25 a of FIG. 2 , which corresponds to a lower electric current. In another embodiment, the constant I·RPM control is used when the electric current is lower than a value, which is predetermined or chosen during the operation.
Constant RPM Control
[0086] In some ventilation systems, the constant I·RPM control may not very well emulate the relationship illustrated in FIG. 2 in certain static pressure range. It is particularly true in the high static pressure range 25 b , in which the motor's speed changes much less than the changes of the static pressure. Thus, in one embodiment, the controller 305 runs in a constant RPM control mode, in which the motor's rotational speed (e.g., RPM) stays constant or substantially constant in the high static pressure range 25 b . Here, a substantially constant RPM means that the motor's RPM remains within a range as the static pressure changes. The range for a substantially constant RPM can be about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 percent of the total range in which the motor's RPM can change. Optionally the range is about 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5 or 6 of the total RPM range. Alternatively, the RPM range can be about 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 percent of the rated speed (RPM 0 ) of the motor. Optionally the range is about 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5 or 6 percent of the rated speed (RPM 0 ) of the motor.
[0087] In embodiments, the motor controller conducts a feedback control of the motor operation to achieve the constant RPM control. In one embodiment, the feedback control attempts to make the motor's rotational speed reach a target value. During the feedback control, the rotational speed changes in the vicinity of the target value. In another embodiment, the feedback control makes the rotational speed stay within proximity of a target value. Here, the rotational speed is in the vicinity or within proximity of a target value when its value at a given time is apart from the target value by less then about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 percent of the total range in which the motor's rotational speed can change. Optionally the proximity range is less than about 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5 or 6 of the total range of the rotational speed. Alternatively, the rotational speed is within proximity of a target value range when its value at a given time is apart from the target value by less then about 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 percent of the rated rotational speed (RPM 0 ) of a particular motor. Optionally the proximity range is less than about 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5 or 6 percent of the rated rotational speed (RPM 0 ).
[0088] Referring to FIG. 5 , line 23 b represents this constant RPM control in the static pressure range 25 b . In one embodiment, the constant RPM control is applied to only part of the range 25 b . In the constant RPM control embodiments, maintaining the motor's speed constant creates a substantially constant airflow although that control may not exactly emulate the profile in FIG. 2 . Also, maintaining the motor's speed constant may at least achieve a result in which the airflow rate stays within a range, which is wider than narrow. The constant RPM control is very useful in ventilation systems, which do not require a strict constant airflow control in a high static pressure range.
[0000] Transition between Constant I·RPM Control and Constant RPM Control
[0089] In FIG. 5 , the line 23 b represents the constant RPM control, and the line 23 a represents the constant I·RPM control. As indicted in FIGS. 2 and 5 , the static pressure is generally inversely proportional to the load applied to the fan and motor. Given that the load is generally proportional to the current, the transition between the two controls can be determined based on the electric current (I). In one embodiment, when the electric current is smaller than a reference electric current, the constant RPM control is chosen; and when the electric current is greater than the reference electric current, the constant I·RPM control is used. As such, the transitional point 24 is found without an input of the static pressure. The values of the reference electric current will be discussed below.
Multi-Level and Programmable Constant I·R Control
[0090] In one embodiment, the motor control system provides a multi-level constant airflow control, which allows users to choose a target airflow rate from multiple predetermined airflow rates. Each of the predetermined airflow rates is associated with a target value for the constant airflow control. In this embodiment, when a user selects one of the predetermined airflow rates, the controller feedback-controls the operation of the motor such that the product of the I·RPM value or its equivalent reaches and stays at about the target value associated with the user selected airflow rate.
[0091] In one embodiment, the target values associated with the multiple airflow rates are predetermined with reference to a maximum hypothetical I·RPM value, which corresponds to a maximum hypothetical airflow rate available from the ventilation system. In one embodiment, the maximum hypothetical I·RPM value refers to the I·RPM value obtained using the motor's rated current (I 0 ) and rated RPM (RPM 0 ) as in Formula 6.
[0000] Maximum hypothetical I ·RPM value= I 0 ·RPM 0 (6)
[0092] In one embodiment, the target values associated with the multiple airflow rates are predetermined with reference to a maximum hypothetical I·RPM value, which corresponds to a maximum hypothetical airflow rate available from the ventilation system. In one embodiment, the maximum hypothetical I·RPM value refers to the I·RPM value obtained using the motor's rated current (I 0 ) and rated RPM (RPM 0 ) as in Formula 6.
[0093] In one embodiment, each target value is a fraction or percentage of the maximum value obtained using Formula 6 or other appropriate formulas. Then, each airflow rate associated with the target value generally represents a corresponding fraction of the maximum hypothetical airflow rate available from the motor. Table 1 is an example listing airflow rates and associated target values that are stored in the controller 305 or an associated memory, in which the motor's maximum hypothetical I·RPM value is 20.
[0000]
TABLE 1
Airflow Rate Levels
Associated Target Values
20%
4
40%
8
60%
12
80%
16
100%
20
[0094] Alternatively or additionally, in one embodiment, the motor control system provides a user programmable constant airflow control, in which users are allowed to input a desired airflow rate or level rather than selecting one of preprogrammed airflow rates or levels. For example, a user inputs 35% level of constant airflow control, the controller 305 computes a target value for the 35% level, which is 35% of the maximum hypothetical I·RPM value of the motor. Then, the controller 305 controls the operation of the motor such that the I·RPM value can reach and stay at the value of 35% of I 0 ·RPM 0 .
[0095] In these embodiments with multi-level and/or programmable constant airflow control, the system includes an appropriate user interface or control panel, with which users can select or input a desired airflow rate level. Further, these embodiments optionally include an appropriate indicator or display device to indicate or display the presently chosen airflow rate level.
[0000] Reference Electric Current for Transition between Controls
[0096] As discussed above, in one embodiment, the transition between the constant I·RPM control and the constant RPM control is determined based on the electric current applied to the motor. More specifically, the reference electric current differs in different airflow rate levels. In one embodiment, the reference electric current is predetermined or calculated using the rated electric current (I 0 ) of the motor. For example, the reference electric current for a certain percent airflow rate has a value of the same fraction of the rated electric current.
[0097] Table 2 is an example listing airflow rates and associated reference electric current for transitioning between the constant RPM control and the constant I·RPM control.
[0000]
TABLE 2
Airflow Rate Levels
Reference Electric Current
30%
0.3 × I 0
50%
0.5 × I 0
70%
0.7 × I 0
90%
0.9 × I 0
100%
I 0
Multi-Level and Programmable Constant RPM Control
[0098] In one embodiment, the motor control system provides a multi-level constant speed (RPM) control, which allows users to choose a target speed value from multiple predetermined speed values. Alternatively or additionally, in one embodiment, the motor control system provides a user programmable constant RPM control, in which users are allowed to input a desired RPM value or level rather than selecting one of preprogrammed RPM values.
[0099] In one embodiment, the target RPM values are predetermined with reference to the rated RPM (RPM 0 ) of a motor or another reference RPM value. In one embodiment, each target RPM value is a percentage or fractional level of the rated RPM (RPM 0 ) or the other reference value. In these embodiments, in a percentage level is chosen or inputted by a user for the performance of the constant RPM control at an RPM corresponding to the percentage level.
[0100] In these embodiments with multi-level and/or programmable constant RPM control, the system includes an appropriate user interface (not illustrated) or control panel (not illustrated), with which users can select or input a desired airflow rate level. The feature of user selection or programming of the motor speed is particularly useful to technicians who have developed certain senses about the correlation between the motor's speed and airflow rates. These technicians and experts could find a good approximation about the motor's speed to accomplish a desired airflow rate, which can be inputted to the motor control system for the constant RPM control. Further, these embodiments optionally include an appropriate indicator or display device to indicate or display the presently chosen airflow rate level.
Overall Process for Constant Airflow Control
[0101] FIG. 6 is a flowchart of the process of constant airflow control according to an embodiment. In step 601 , a user selects or inputs a desired level of airflow rate for a constant airflow control using a user interface or a control panel of the motor or motor controller 305 . In one embodiment, the selection or input of the desired level sets a desired airflow rate for the constant I·RPM control and also for the constant RPM control. In another embodiment, the desired level determines the desired airflow rate for the constant I·RPM control, and the user may need to provide a desired level of motor speed for the constant RPM control. Thus, optionally, in step 603 the user selects or inputs a desired level of motor speed, which may occur prior to step 601 in some embodiments.
[0102] Then, the user turns on and runs the motor. After a transient period for a certain rotational speed, in step 605 the controller 305 compares the electric current (I) to the reference electric current calculated based on the desired level of airflow rate. For example, in case the inputted desired level is 70%, the reference electric current is 70% of the rated electric current of the motor. In this comparison, if the electric current applied to the motor is greater than the reference electric current, the controller 305 selects the constant I·RPM control 607 . On the other hand, if the electric current applied to the motor is smaller than the reference electric current, the controller 305 selects the constant RPM control 609 . In one embodiment, during the operation, the controller 305 goes to step 605 and conducts the comparison constantly to determine whether to transition from one control to the other. Alternatively, the comparison of step 605 can be conducted periodically or sporadically to determine the need for transition between the controls.
[0103] FIG. 7 illustrates the relationship between the motor speed (RPM) and static pressure in multi-level constant airflow controls, including three profiles similar to FIG. 5 . The profile A represents 10% level of airflow rate control; the profile B represents 50% level; and the profile C represents 70% level. Each profile includes a constant RPM control section in the static pressure range from the maximum to a midpoint referred to as constant rate point (CRP). Also, each profile transitions to a constant I·RPM control in the static pressure range from the midpoint to the minimum static pressure. FIG. 8 illustrates the relationship between the static pressure and the airflow rate in the multi-level constant airflow controls corresponding to FIG. 7 . In Profile C, the portion 801 corresponds to the higher static pressure range in which the constant RPM control is conducted; and the portion 803 corresponds to the lower static pressure range in which the constant I·RPM control is conducted.
Correction of Motor Output Variations
[0104] Motors produced with the identical design and manufacturing may not have the identical operating characteristics. Also, motors produced in the same batch may have slight differences in their responses to certain controls. Further, a single motor can have different responses to the same control action when the motor operates under different contexts, such as different designs (size, weight, configurations, etc.) of the fan coupled with the motor and different designs of the ventilation duct (size and configurations). The results of these are deviations and variations from a computed output when a control action is taken. In the constant I·RPM control or the constant RPM control, for example, the motor's response to a control action to achieve a target value can result in a slight deviation from the target value although the response is good enough to produce a generally desired result, i.e., a substantially constant airflow rate.
[0105] According to one embodiment, the controller 305 corrects these variations and deviations for better constant airflow controls. More specifically, the controller 305 conducts one or more test operations, and collects certain data specific to at least one of the motor, fan and duct configurations. In one embodiment, the test operation is carried out when the motor is coupled with a particular fan and installed in a particular ventilation duct or system. In one embodiment, the collected data are stored in a memory associated with the controller 305 and used to minimize the deviations so as to accomplish that the motor operation is close to the profile of FIG. 2 for at least part of the static pressure span. In one embodiment, the data are further processed to produce a reduced form of data that has more direct correlation with the control of the motor operation. The reduced form of data is then stored in the memory and used to achieve a desired operation of the motor for a substantially constant airflow rate.
[0106] FIG. 9 is a flow chart of a process according to embodiments for correcting the motor output variations. In step 902 , a test operation of the ventilation system is performed under its minimum static pressure condition. During the test operation, in step 904 , the electric current applied to the motor is monitored while changing the motor's speed (e.g., RPM). In step 906 , the current and RPM data obtained from the test operation is processed to produce a coefficient (e.g., Kr), which can represent deviations in the actual motor operations from its corresponding computed value at different levels of airflow rates. In step 908 , a correction coefficient for compensating or correcting the deviations is obtained for each airflow rate level, and in step 910 the correction coefficient is stored in a memory associated with the controller. Then, in step 912 , the motor is operated for a constant airflow control, and a control target value is compensated using the stored correction coefficient values. Various features and embodiments of the test operation and the controlled operation will be further discussed.
Test Operation
[0107] In one embodiment, the test operation is performed under the same or very similar condition where the motor is operated for ventilation. In this embodiment, in order to conduct the test, the motor is assembled with a fan and installed in the ventilation system to blow air through the duct. Thus, the test results from the test operation reflect the conditions of actual operation of the ventilation system, such as, size, design and weight of the fan, and the configuration of the duct.
[0108] During the test operation, the motor is operated under the minimum static pressure condition. The ventilation duct has one or more outlets through which air blown from the fan is discharged. In one embodiment, the minimum static pressure condition can be created by opening the outlets to their maximum size. During the test operation, the motor is run while changing the RPM by changing the length of period during which the electric current is applied to the motor. In one embodiment, the motor's RPM is increased and/or decreased gradually, stepwise, randomly or in combination. In one embodiment, the motor's RPM is continuously and gradually increased. While changing the motor's RPM, the electric current applied to the motor is monitored. In embodiments, the RPM and current at each time are recorded continuously, intermittently or in combination. FIG. 10 illustrates examples of recorded current-RPM relation for three different motors or three different conditions for the same motor.
[0000] Processing Data from Test Operation
[0109] In step 906 of FIG. 9 , the controller processes the data obtained from the test operation so as to produce Kr values. In one embodiment, Kr is a coefficient obtained using Formula 7, in which β is a coefficient having a constant value.
[0000] Kr=β·I /RPM (7)
[0110] In one embodiment, β equals to “1”, where Kr=I/RPM. The Kr values obtained using Formula 7 is plotted against the motor's speed in FIG. 11 . In one embodiment, the Kr-RPM relation as in FIG. 11 is then converted to the relation between Kr values and different levels of airflow rate of the particular motor in the particular ventilation system. Here, the term “different levels of airflow rate” refers to various fractions of the maximum airflow rate of the motor. In one embodiment, the maximum airflow rate is the airflow rate obtainable when the rated electric current (I 0 ) and rated speed (RPM 0 ) of the motor are achieved. Using Formula 4, the maximum airflow rate is represented with the maximum hypothetical I·RPM value (I 0 ·RPM 0 ) in Formula 8.
[0000] Q 0 =α·I 0 ·RPM 0 (8)
[0111] In one embodiment, the conversion of the Kr-RPM relation to the Kr-airflow rates relation can be based on the relation between RPM and airflow rates of the motor. Typically, the RPM of a motor is proportional to the airflow rate generated from the motor when the static pressure of the ventilation duct does not change. For example, the RPM-airflow rate relations 1201 , 1202 of two motors are plotted in FIG. 12 . In one embodiment, using the proportional relation between the RPM and airflow rates, the Kr-RPM relation in FIG. 11 can be converted to the Kr-airflow rate relation. In other embodiments, the Kr-RPM relation is converted to the Kr-airflow rate relation using a linear or non-linear relation between the RPM and airflow rates of a particular motor.
[0112] FIG. 13 plots the Kr-airflow rate relation converted from the Kr-RPM relation of FIG. 11 according to one embodiment. The maximum RPM of FIG. 11 corresponds to the maximum airflow rate of FIG. 13 , and each fractional level (e.g., percentage) of the maximum RPM of FIG. 11 corresponds to a fractional level (e.g., percentage) of the maximum airflow rate of FIG. 13 . Although FIGS. 11 and 13 plot the Kr-RPM and Kr-airflow rate relations continuously, in actual embodiments these relations may be generated discontinuously. Optionally, although not included in the flowchart of FIG. 9 , the resulting Kr-airflow rate relation in a continuous or discrete format is stored in a memory associated with the controller.
[0113] In step 908 of FIG. 9 , a correction coefficient is obtained for each airflow rate or its fractional level. The correction coefficient can represent deviations in the actual motor operations from its corresponding computed value at different levels of the airflow rate. Thus, the correction coefficient can be used to compensate the deviations at different levels of the airflow rate. In one embodiment, the correction coefficient represents the size of deviation of the Kr value from the corresponding value computed using the rated current and rated RPM. In one embodiment, the correction coefficient (γ) is represented by Formula 8.
[0000] γ· K 0 =Kr (8)
[0114] In one embodiment, K 0 denotes the Kr counterpart that is computed using the rated current and rated RPM as in Formula 9.
[0000] K 0 =I 0 /RPM 0 (9)
[0115] Subsequently, in step 910 , at least part of the resulting data is stored in a memory associated with the controller. The resulting data includes Kr values, K 0 values, correction coefficients (γ) for various airflow rates or their fractional levels. In one embodiment, only correction coefficient (γ) and the corresponding airflow rate or its fractional level are stored in a memory. In embodiments, either or both of the Kr values and the K 0 values are also stored in the memory. In one embodiment, the resulting data are stored as a table, in which each airflow rate value has a corresponding value of the correction coefficient (γ) and optionally other data obtained from the foregoing processes. Table 3 is an example listing the values of Kr, K 0 and γ for each airflow rate.
[0000]
TABLE 3
Airflow Rate
Levels
Kr 0
Kr
γ
10%
0.1 · I 0 /RPM 0 = 0.00018
0.00019
0.947
20%
0.2 · I 0 /RPM 0 = 0.00024
0.00025
0.960
30%
0.3 · I 0 /RPM 0 = 0.00030
0.00032
0.938
40%
0.4 · I 0 /RPM 0 = 0.00038
0.00038
1
50%
0.5 · I 0 /RPM 0 = 0.00043
0.00045
0.956
60%
0.6 · I 0 /RPM 0 = 0.00062
0.00060
1.033
70%
0.7 · I 0 /RPM 0 = 0.00075
0.00073
1.027
80%
0.8 · I 0 /RPM 0 = 0.00085
0.00082
1.037
90%
0.9 · I 0 /RPM 0 = 0.00092
0.00091
1.011
100%
1 · I 0 /RPM 0 = 0.00099
0.001
0.99
[0116] According to the embodiment represented in Table 3, the airflow rate is stored as a fraction (e.g., percentage) of the maximum airflow rate although not limited thereto. Likewise, the Kr and K 0 values corresponding to airflow rates can be stored as a fraction (e.g., percentage) of their maximum values or as their actual values calculated from appropriate formulae using the data obtained during the test operation. In other embodiments, the airflow rate levels are not represented in discrete numbers (e.g., 1, 2, 3, . . . , N- 1 , N) rather than fractions of the maximum airflow rate as also shown in FIG. 13 (see the numbers below the horizontal line).
More Accurate Constant Airflow Control
[0117] In step 912 of FIG. 9 , the controller 305 uses the data stored in the memory for a more accurate constant airflow control. In embodiments, the correction coefficient (γ) is factored in to produce a modified target value in the constant I·RPM control or the constant RPM control. Each control changes a certain variable, such as the pulse width during which the electric current is applied, so as to drive the value of a formula to a target value. In certain embodiments discussed above, the target values for control is obtained or computed based on the rated values, such as the rated electric current and rated speed of the motor, which are determined from manufacturing. Now, in one embodiment, the target values are adjusted or modified based on data drawn from the motor's test operation, including the correction coefficient. More specifically the target values are modified differently at different levels of airflow rate.
[0118] In one embodiment of the constant I·RPM control, the target value is a fraction of the hypothetical maximum I·RPM. In the embodiment, this target value is adjusted using the correction coefficient (γ). In one embodiment of the constant RPM control, the target value is a fraction of the rated speed (RPM 0 ). In another embodiment of the constant RPM control, the target value is a user inputted target RPM. In these embodiments, the target value is adjusted using the correction coefficient (γ).
[0119] According to embodiments of the invention, the system provides a controller that allows the constant airflow control at various target airflow rates. Further, the controller provides for the adjustment of the constant airflow control based on the RPM and electric current relationship obtained from a test operation to make the control more accurate. These controls make the airflow rate remains substantially constant irrespective of significant changes of the static pressure in certain static pressure ranges.
Response Rate Correction
[0120] In one embodiment, constant airflow controls can be further modified and improved based on the response rate of the motor. Generally, the larger or heavier the fan coupled with the motor is, the smaller the response rate of the motor is preferred; and the smaller or lighter the fan is, the larger the response rate is preferred. In one embodiment, the system provides a user interface or control panel, with which the motor operator selects or inputs a desired motor response rate. Using this feature, the motor operator can further improve the constant airflow control to accomplish substantially constant airflow rate over the static pressure changes. Particularly, when the fan is replaced, an operator or technician can set a desired response rate based on at least one of the new fan's configuration, size and weight.
Controller Circuits
[0121] In various embodiments, the motor controller can be implemented in various ways including both software and hardware. FIG. 14 illustrates an exemplary controller according to an embodiment of the invention. In the illustrated embodiment, the motor controller includes an electronic control circuit 70 . The electronic control circuit 70 includes a power switch circuit 4 , a gate circuit or drives 5 and a logic circuit 6 . The power switch circuit 4 has an output connected to a motor 2 via a line 12 and supplies a motor coil with switching power, such as a single-phase, two-phase or three-phase for driving a fan 1 . The motor 2 can be an electrically commutated motor (ECM) or a brushless motor (BLM) although not limited thereto. The gate circuit 5 is provided for driving the power switch circuit 4 , and a logic circuit 6 is provided for controlling a control signal suitable for each motor driving method.
[0122] In the illustrated embodiment, the motor controller further includes a current detection circuit 8 for detecting a load current 22 flowing through the motor coil, and a rotor position detection processing circuit 3 for processing a pulse of a position detection signal of a motor rotor. The current detection circuit 8 is connected to an input of a microprocessor 7 via a line 23 . The rotor position detection processing circuit 3 is connected to the inputs of the microprocessor 7 and the logic circuit 6 via lines 16 and 15 , respectively.
[0123] Further, in the illustrated embodiment, the motor controller further includes an input device 46 , which has a maximum speed setting unit 10 for use in setting a target RPM corresponding to various airflow rates. Further the input device 46 includes an airflow rate setting unit 11 for setting various levels of constant airflow rates. The maximum speed setting unit 10 and the constant rated airflow setting unit 11 are connected to a multi-program interface circuit 9 via lines 18 and 19 , respectively. The multi-program interface circuit 9 has an output connected to the input of the microprocessor 7 via line 17 .
[0124] The motor controller of the illustrated embodiment further includes an interface circuit 47 , a pulse width modulation (PWM) unit 48 , and a DC variable voltage unit 49 . The interface circuit 47 is configured to process a PWM signal (generally 80 Hz) for speed setting, which is supplied from the external system or control device through the pulse signal supply unit 48 , and a variable DC voltage (0 to 10V) supplied from the DC variable voltage unit 49 by using a single terminal. The interface circuit 47 is connected to the input of the microprocessor 7 via line 50 .
[0125] The microprocessor 7 is configured to process data to control motor so as to operate in a constant airflow rate mode based on the acquired data from the sensor circuits, and transmit a PWM signal (for example, 20 Khz) for speed control. The output signal is transmitted to the logic circuit 6 of the electronic control circuit 70 via a line 21 .
[0126] In one embodiment, the controller has a set of commands for performing a self-testing operation. In the test operation of the ventilation system, when the motor driving power switch 402 turns on, the motor is operated to rotate the fan from a still state to a preset maximum speed as the microprocessor 7 outputs a PWM output signal while being automatically modulated 0 to 100% according to a self-driving test operation commands of the microprocessor 7 . At this time, from the load current 22 and the speed signal 16 , the microprocessor 7 acquires current data, speed data, and a peak current rate, which may vary according to various different fan loads and environments, and determines the current-speed relation as shown in FIG. 4 .
[0127] Now referring to FIG. 15 , for example, a variety of fans or blower of the fan 1 can be connected to the motor 2 used in a ventilation and air conditioning (HVAC) system. The motor 2 may include an ECM or BLM of a single-phase, two-phase or three-phase or more. The power switch circuit 4 has full bridge FET elements 4AH, 4AL, 4□H, and 4□L, and is connected to one upper winding of the coil of the motor 2 .
[0128] Each of gate driving circuit sections 24 and 25 of the gate circuit 5 for driving the FET elements of the power switch circuit 4 may include a gate drive-dedicated circuit such as IRS2106. The gate circuit 5 is connected to the power switch circuit 4 and the logic circuit 6 having logic circuit units 30 and 31 for processing the speed signal and the PWM signal.
[0129] The power switch circuit 4 is connected to the current detection circuit 8 having a resistor 26 with a resistance of about 0.1 to 0.5Ω, a resistor 27 , and a capacitor 28 connected to a motor control circuit ground. A voltage formed in the resistor 26 is integrated when a current flows, and the voltage signal is input to an amplifier 29 . The voltage is transmitted to the microprocessor 7 via a line 23 . In order to input motor speed (RPM) information from the rotor position detection processing circuit 3 of the motor 2 employing a sensor or back-EMF of an armature coil, the signal is transmitted to the input of the microprocessor 7 via a line 16 .
[0130] Further, the output of the program input device 46 is connected to a transmission line 39 of a RS485 processor 36 . The output signal is to control and monitor a maximum speed setting unit 10 and a constant rated airflow setting unit 11 enabling a multi-level programming for constant airflow control according to one embodiment. A transmission output R of the RS486 processor 36 is connected to a data input RXD of the microprocessor 7 through a photo coupler 34 . A data output 43 of the microprocessor 7 is connected to a receiving input of the program input device 46 via the photo coupler 33 , the RS485 processor 36 and a line 40 . A data communication control (CTRL) signal 45 of the microprocessor 7 is connected to a control terminal of the RS485 processor 36 through the photo coupler 35 . Accordingly, the program data can be supplied to the microprocessor 7 smoothly, and grounds 41 and 42 can be electrically insulated from an external program input device 46 .
[0131] Further, an interface circuit (SCI) 47 has a speed signal conversion microprocessor 56 built therein. The speed signal conversion microprocessor 56 serves to interface a DC variable voltage unit 49 and a pulse width modulator 48 for generating a variable DC voltage of about 0 V to about 10 V and a PWM signal, which is used for speed control or setting, in response to a control signal of an external system controller, to one terminal. Now an embodiment of the speed signal conversion microprocessor 56 is further described.
[0132] Referring to FIG. 16 , in one embodiment, when a DC variable voltage unit 49 is selected by a switch 65 , a DC voltage is input to an input PB 1 of the speed signal conversion microprocessor 56 through an OP amp 58 . The DC voltage passing through a resistor 64 is cut off by a DC filter capacitor 59 . Meanwhile, when a predetermined DC voltage is input to the input PB 1 , the speed signal conversion microprocessor 56 is programmed to output a pulse width modulation signal of 80 Hz (an output signal shown in FIG. 15B ), which is proportional to a voltage level thereof. The output signal PBO of 80 Hz is connected ( 54 ) to a base of a transistor 53 . An output of a photo coupler 52 is connected ( 55 ) to a base of a transistor 51 . Accordingly, a PWM signal of 80 Hz, which is fully insulated electrically, is output through a collector 50 of the transistor 51 .
[0133] If a PWM signal of 40 to 120 Hz is connected to the input of the switch 65 , a signal whose voltage is divided into the resistor 64 and the resistor 63 is input to a base of a transistor 61 . An AC component of a pulse by switching of the transistor 61 is input to an input PB 2 of the speed signal conversion microprocessor 56 through the two capacitors 59 and 60 .
[0134] The speed signal conversion microprocessor 56 has a program built therein, for outputting a PWM signal of 80 Hz according to an increase or decrease of a pulse width on the basis of a rising point a of a pulse, a falling point b of the pulse, and a rising point c of 1/f cycle of the pulse, as shown in FIG. 17B , although an input PWM signal frequency is not constant as in INPUT (40 to 120 Hz) of FIG. 17A . Accordingly, a PWM output of 80 Hz can be always output accurately although there is a change in an input PWM frequency.
[0135] Embodiments of the present invention provide an input method, which is capable of setting a constant rate point (CRP) and a maximum speed (or target RPM). Thus, as shown in A, B, and C of FIG. 8 , various levels of constant airflows can be set and a constant airflow can be realized accurately with a reasonable tolerance and conveniently. According to embodiments of the present invention, although an unknown load is connected to a motor, the motor can be driven according to a self-driving program and a load current and speed of the motor are automatically found to calculate a constant airflow control function. It is thus not necessary to install an additional sensor for detecting static pressure inside the duct nor to input constant airflow data.
[0136] Further, embodiments of the present invention provide an input method capable of arbitrarily setting a constant rated point CRP and a maximum speed. Accordingly, constant airflows can be set in various ways such as (A), (B), and (C) of FIG. 8 , and an accurate constant airflow can be set conveniently. Further, there is an advantage in that a PWM or DC variable voltage signal for speed control, which is provided from a HAVC system controller, can be processed stably and easily. Furthermore, embodiments of the present invention can simplify a constant airflow control device and system, save a time and cost consumed to calculate and set constant airflow program and data necessary for different fans and blowers, and maximize amenity and energy saving effects, which are expected in HAVC control.
[0137] It is to be understood that persons of skill in the appropriate arts may modify the invention here described while still achieving the favorable results of this invention. Accordingly, the foregoing disclosure is to be understood as being a broad, teaching disclosure directed to persons of skill in the appropriate arts, and not as limiting upon the invention. | A method of constant airflow control for a ventilation system is disclosed. The method includes various controls to accomplish a substantially constant airflow rate over a significant change of the static pressure in a ventilation duct. One control is a constant I·RPM control, which is primarily used in a low static pressure range. Another control is a constant RPM control, which is primarily used in a high static pressure range. These controls requires neither a static pressure sensor nor an airflow rate sensor to accomplish substantially constant airflow rate while static pressure changes. This is because these controls use only intrinsic control variables which are electric current and rotational speed of the motor. Also, the method improves the accuracy of the control by correcting certain deviations that are caused by the motor's current-RPM characteristics. To compensate the deviation, the method adopts a test operation in a minimum static pressure condition. Also disclosed is an apparatus for conducting these control methods. | 5 |
FIELD OF THE INVENTION
The invention concerns aquatic sports and activities, such as canoeing and wherein, rivers are used in which nautical stages are provided to allow for the teaching of sailing enthusiasts and the running of competitions.
BACKGROUND OF THE INVENTION
Water sports, and more particularly canoeing and kayaking, are a constantly growing leisure activity. To cope with this demand, several types of aquatic passages are used.
The first type is constituted by natural rivers offering a unique framework for sailing enthusiasts and which require little equipment or accessories, such as markers or beacons suspended above the river so as to subsequently lay out a specific passage or route in the bed of this river to be traversed.
A second type of aquatic passage is offered by pseudo-natural passages which are facilities of rivers with the aid of natural or concrete layers of broken stones. In fact, the bed of the river is modified by the creation of artificial volumes by means of concrete masses installed in the river bed.
A third type of aquatic passage is constituted by artificial rivers obtained by, for example, diverting one portion of the flow of a river into an artificial canal or by means of pumping water from a river or reservoir into an artificial canal.
These types of aquatic passages or courses only offer, for a specific river, a single determined immovable flowing path of the water of the river. In other words, the bed and the flow from the river are definitively fixed.
Moreover, the development of these nautical activities is such that these running water stages are the main driving elements required for carrying out these sports and in particular for canoeing and kayaking.
The object of the invention is to develop a nautical passage avoiding said drawbacks and able to offer the possibility of changing the course to be traversed within the river so as to diversify the possible passages to be made on this river, while avoiding modifying the overall river bed.
SUMMARY OF THE INVENTION
To this effect, one first main object of the invention concerns a method for providing a nautical course in running water and intended for nautical activities and consisting of modifying the river bed by placing or creating artificial volumes in the river bed. According to the invention, it consists of carrying out the following stages steps:
partially draining the river;
placing on the river bed, at each location where it is desired to create a volume, at least one base provided with holes opening on its upper surface;
placing inside the holes or bases each element having one portion going into these holes so as to constitute said artificial volumes, and
refilling the river,
so as to thus create a temporary nautical passage.
One improvement of this method consists of interconnecting several vertical elements by a linking piece so as to render them integral and define larger artificial volumes.
It is also possible to interconnect certain elements by an intermediate board so as to thus increase the artificial volumes created by these elements.
The second main object of the invention concerns a device to provide an aquatic passage in running water, especially for nautical sports, by modifying the bed of a river and including:
bases to be laid on the river bed, and
elements secured to the bases and having one voluminous upper portion for constituting one portion of the artificial volumes in the river bed.
The bases, which may be made of concrete, are preferably have holes in the upper surface thereof and the elements each have a rod to fix them in said holes.
In this case, the holes are discharging and vertical with respect to the bases.
In this embodiment, the bases each have several depending feet so that the bases are elevated with respect to the river bed in order to provoke a circulation around and through the bases for the purpose of cleaning the holes.
The upper portion of certain elements may be constituted by a polyethylene casing molded around the rod 1 which extends over the entire height of the element, or a vertical cylinder with a lower rod being fixed to the base of said cylinder by means of a concrete sleeve.
Thus, it is possible to define the desired passage by firstly placing concrete bases at certain locations and equipping them with one or several vertical elements.
One preferred embodiment of the invention provides that the elements are each constituted by a vertical cylinder, itself constituting the upper portion where the lower rod is fixed by means of a concrete sleeve.
These cylinders are advantageously completed by forming handling orifices in the wall of each cylinder which allows the river water to flow into the cylinder when returning the water to the river and flow out of the cylinder when draining the river.
In this embodiment, each vertical element may be completed by a round cover or cap provided with at least one hole.
It is also possible to use multiple covers constituted by several round caps each provided with at least one hole so as to place on the top of several adjacent cylinders. Thus, larger volumes are created.
The cylinders and covers may be made of either polyvinyl chloride or polyethylene.
Preferably, the holes of the bases are lined with a sleeve preferably made of metal.
Preferably, the sleeve is provided with grooves on its internal surface.
Similarly, the rods preferably have longitudinal grooves.
Another feature of the invention consists in that the upper portions of certain elements are provided with grooves to receive upper intermediate planks placed between two elements and thus increasing the artificial volumes created by the elements.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention and its characteristics shall be readily understood on reading the following detailed description of the preferred embodiments of the present invention with reference to the accompanying drawing, wherein:
FIG. 1 is a sectional view of a first embodiment of one element and a base of the device of the invention;
FIG. 2 is an elevated view of an assembly of several vertical elements constituting a determined volume;
FIG. 3 is a top view corresponding to FIG. 2;
FIG. 4 is a second embodiment of one element of the device of the invention, and
FIG. 5 is a top view using the elements of FIG. 4.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to FIG. 1, the main first portion of the device of the invention consists of creating a set of bases 1, preferably made of cement, and intended to be placed on the floor of the river bed 5, namely at the bottom of the latter. The main characteristic of these bases 1 is that they can be fixed above the elements 10 which shall constitute artificial volumes. As shown in the illustrated detailed embodiment, this is possible in that each base 1 has a set of holes 2, for example vertical and opening onto the upper surface 3 of the base 1 in question. The fact that these holes 2 are open at each end makes it possible to avoid any suction effect when an object is introduced or removed from these holes 2. They are preferably reinforced by a sleeve or sheath 4 which may, for example, be made of metal so as to increase their resistance to wear and ensure the lateral stability of the artificial volumes created in the river.
It is equally preferable to provide feet 22 underneath the bases 1 to support and elevate the base 1 from an underlying river bed 5. In fact, if said bases are surrounded by water, the current may allow for a systematic cleaning of the holes 2 when they are open, i.e. when elements 10 are not inserted therein.
It is therefore possible to consider using these bases 1 whose sides may vary, for example from 1 to 3 meters. Having regard to the fact that these bases 1 are preferably made of concrete, they typically need to be handled by means of a crane.
The second main element of the device of the invention is constituted by a set of elements 10, for example vertical elements, intended to establish an artificial volume in the river bed and able to divert or direct the flow of water of the latter. So as to be able to be fixed in a concrete base 1, the embodiment shown provides that each element 10 has at its lower portion a fixing rod 11 whose shape corresponds to the internal diameter of the sheath 4. In this respect, not only is the shape complementary to the internal shape of the sheath 4 (a cylindrical tube if the sheath 4 is cylindrical), but also all shapes may be inscribed there. Thus, it is possible to use cylindrical fixing rods 11 in the sheaths 4 whose internal shape is circular in which the external surface of the rods is inscribed.
In one first embodiment, and so as to facilitate the handling of this vertical element 10, the lower rod 11 may advantageously be embodied in the form of a hollow metallic profile. It is fixed to one upper portion 12 of the vertical element 10 which is hollow voluminous. In fact, the upper portion 12 constitutes the operational portion with regard to the flow of the river to be modified. The fixing of the lower rod 11 to the upper voluminous portion 12 may be advantageously effected with the aid of a linking concrete constituting a fixing sleeve 13. Thus, it is possible to equip, not merely any base 1 of one or several vertical elements 10 for constituting an artificial obstacle in the river bed, but also place this artificial obstacle at a desired location by placing the base 1 at the corresponding location at the bottom of the river.
With reference to FIGS. 2 and 3, it can be immediately seen that the device of the invention is able to embody any type of artificial obstacle of any shape in the river bed, considering that the placing of bases 1 is possible on the bottom of said bed. In fact, FIG. 2 shows four vertical elements 10 placed beside one another. In effect, it is preferable that the distance between the holes 2 of the bases 1 corresponds to the diameter or width of the vertical elements 10. In this way, with them placed adjacently, these elements are able to play the role of a dike with respect to the water of the river.
FIG. 3 shows a top view of one possible embodiment of an obstacle shown by FIG. 2. In fact, in considering the edge 20 of the river, it can be seen that the placing of one or several bases on the side of the bed close to this edge 20 makes it possible to construct a projection 21 constituted by eight vertical elements 10 placed in such a way as to obtain the desired shape. Thus, a diversion of the flow of the river is created, that is an artificial turning.
The embodiment of FIG. 3 shows that the holes 4 are placed diagonally or zig-zag with respect to the edges 20 of the river bed. This is merely one embodiment example, the bases being able to be disposed anywhere, such as at the bottom of the river, and likewise the placing of the holes 2 in these bases 1 could be provided in any type of geometry. However, it is preferable that their position and spacing are able to constitute compact volumes. It can also be readily understood that if one or several bases 1 are placed in the middle of the river, it is possible to create, not merely a projection of the edge 20 of the river, but also an artificial island in the middle of the river bed.
With reference again to FIG. 1, for handling the vertical elements 10, at least one handling hole 14 is made in the wall of the upper portion 12 of the vertical elements 10. It is moreover advantageous that these holes 14 have a handle shape. Thus, the vertical elements 10 can be placed manually in the holes 2 of the bases 1 at the desired locations.
In this respect, it ought to be mentioned that the invention is preferably applicable to rivers able to be at least partially denuded of water, that is able to be significantly drained. Once the vertical elements 10 have been placed, the river may be filled with water. The handling holes 14 then enable the vertical elements 10 to remain in the bases 1 without floating. In fact, these fixing holes 14 allow water to progressively enter into each of the vertical elements. The embodiment of the lower rods 11 with the aid of hollow profiles allows for a possible circulation of water inside the vertical elements 10 below the bases 1 if the holes 2 do not open imperviously on the bottom 5 of the river. Finally, it is advantageous to provide a draining hole 19 in the bottom of the upper portion 12 so as to enable the water to flow out of the upper portion 12 when draining the river prior to any possible movement of the vertical element. This type of hole 19 may also be used as a handling hole once it has assumed the correct shape.
One first preferred embodiment of the upper portion 12 of the vertical elements 10 is of using relatively wide cylinders. These may in particular be PVC draining pipes, that is made of polyvinyl chloride or polyethylene.
These vertical elements 10 are each advantageously capped or completed by a round cover 15 placed at the top 16 of a vertical element 10. The cover 15 makes it possible to prevent users of the aquatic course from jamming a leg or arm in one of the vertical elements 10. Preferably, at least one hole 17 is provided traversing each of the covers 16 so as to allow air to escape during the gradual filling of the inside of the vertical elements 10 when water is placed back into the river.
In the case shown in FIGS. 2 and 3, it is advantageous to have a linking piece, such as a multiple cap 18 constituted by round individual covers rendered integral with one another. This multiple cap 18 is able to stiffen the structure created by means of several adjacent vertical elements 10.
Single or multiple covers may also be constituted by the same material as that of the upper portion 12 of the vertical elements 12, that is PVC or polyethylene.
The weight of this vertical element may then be about sixty kilograms for a length of between one 1.5 and 2 meters. These vertical elements 10 are able to resist a water level difference on opposite sides of the vertical element equal to one meter. Thus, it can be conceived that it is possible to set up local fast currents and deviations of the flow of the river so as to simulate obstacles and difficult situations on an aquatic course, such as rapids.
The above-discussed preferred embodiment of the invention provides that the lower rod 11 of the vertical elements 10 is a cylindrical rod and that the corresponding holes 2 are also cylindrical. This is merely one embodiment, these two elements being able to have different but corresponding shapes.
Similarly, the section of the vertical elements 10 need not be cylindrical but may be square or have a shape more suited to the configuration of the obstacle it is desired to create. In particular, they may have a shape complementary to the bank of the river opposite the location where they are placed so as to allow an obstacle to be in intimate contact with the latter and thus prevent the waler from flowing alongside the bank.
With reference to FIG. 4, a second preferred embodiment of the elements mainly consists of molding a synthetic material, such as polyethylene, around a large rod 25 extending over the entire height of the element. Thus, a vertical element 10 is formed having a casing 23 able to have any shape. Thus, it is possible to mold a large number of different obstacles so .as to obtain a relatively full set of obstacles for embodying a varied course.
In FIG. 4, the rod 25 is shown with longitudinal grooves 28. This may facilitate the introduction of rods 25 into the holes 2 or the sheath 3 of the holes when there is a small amount of dirt or sand inside these holes. This facility of mounting may also be obtained by making grooves on the internal surface of the sheaths 3 placed in the holes 2. So as to allow for handling of these elements 10, lower grooves 26 may be provided at the bottom of the polyethylene casing 23. Thus, it is possible to provide flanges 27 in the upper portion of these lower grooves 26 so as to form grasping handles.
Secondly, with reference to FIG. 5, it is advantageous to make large longitudinal grooves 31 on one portion or over the entire height of several elements 10 so that an intermediate board 30 can be inserted therein. Thus, a link may be established between two elements 10 so as to offer additional possibilities for forming various obstacles. The intermediate boards 30 may have different heights so as to form a complete obstacle with regard to a boat or a sort of weir for provoking a rapid.
The method of the device of the invention makes it possible to have an open-ended structure able to be placed not only in running water but in a simple sheet of water. This running water stage using this type of obstacle offers a range of possibilities of variations of floats favorable to users. This type of equipment in fact is able to mitigate certain drawbacks appearing at a particular location, such as when the bed of a river provides a passage too difficult for users. On the other hand, it is also possible to create artificial difficulties in the bed of a river which normally does not present a major challenge for experienced users.
In addition, the obstacles can be moved, thus making it possible to vary the currents and movements of the water of a given river at a given location.
Moreover, the elements of the device may easily be standardized. However, the height of the vertical elements 10 may be extremely variable according to the water level of the river or the type of obstacle it is desired to create.
The aquatic courses created as above may possibly be accessible to water sports enthusiasts of all levels when they are associated with the flow variations of the river.
Finally, by virtue of its dismantable nature, the bases and elements can be removed from the river after use to restore the river to its initial natural bed. But it needs to be stated that in the last analysis, the invention is particularly fully adapted to the artificial river arms which have firstly been erected, for example in diverting any disposition installed on or at the edge of the river, such as a dam.
Other embodiments are possible, the concept of the invention residing in the fact of securing elements to bases placed at the bottom of the river to be converted. | A device for creating a specific but temporary aquatic passage in an artificial or natural river. The device includes bases which rest on the bottom of a river and elements which extend upwardly from the bases. The bases have holes formed therein which receive rods that extend downwardly from the elements. Placement of the bases in the river bed, and subsequent installation of elements into the bases, allows obstacles to be created in the river which are desirable for canoeing and kayaking. | 0 |
This application is a continuation-in-part of my copending application entitled "Resonantly Driven Pavement Crusher", Ser. No. 329,149, filed Dec. 10, 1981, now U.S. Pat. No. 4,402,629; which is in turn a continuation-in-part of the patent entitled "Resonantly Driven Vertical Impact System", Ser. No. 157,138 filed June 5, 1980, now U.S. Pat. No. 4,340,255.
BACKGROUND OF THE INVENTION
The present invention relates to pavement breakers in which a cutting or crushing tool is mounted to the output end of a resonantly driven beam, and in particular to the penetration tool used on such devices.
A pavement breaker of the type utilized in connection with the present invention is illustrated in my above-referenced U.S. Pat. No. 4,340,255. The pavement breaker includes a mobile carrier vehicle which rides over the pavement to be broken. A resonant beam having input and output antinodes at its ends and a pair of stationery nodes intermediate its ends is mounted to the vehicle at the nodes. The beam is excited to near its resonant frequency, and a penetrating tool depending from the output end of the beam breaks the pavement underlying the vehicle. The tool may have a relatively narrow striking surface to essentially slice through or cut the underlying pavement, or a wider surface to achieve a pulverizing or crushing action.
The cross-referenced application describes an improvement in the penetrating tool used in the pavement breaker of the type disclosed in the patent. This tool includes a flat bottom surface, and inclined flanges forward and rear. The forward flange strikes the pavement at a relatively small closing angle, between about 6° and 18°, to initially break the pavement. The flat bottom further crushes the pieces broken off by the forward flange. The rear flange is provided so that the tool can be reversed when the flange in use becomes worn.
While the tool described in the cross-referenced application has been found to be quite useful, the required force to break the pavement has been found to increase as the stroke of the tool proceeds toward completion. It has been discovered that this results from the fact that the closing angle, defined as the angle between the direction of motion of the portion of the tool striking the pavement and the inclination of the flange at that point, increases throughout the stroke of the tool. The tool essentially pivots about the adjacent node of the resonant beam, and the increased distance between this node position and the portion of tool striking the pavement increases throughout the stroke of the tool, thus increasing the closing angle.
The system must accommodate the maximum force encountered, which will occur at the end of the stroke in the tool described above. As a result a system with such a tool will operate below its optimum at intermediate portions of the stroke. This system is somewhat unstable because the reaction forces will vary with the depth of penetration of the tool and also with irregularities in the surface being broken.
SUMMARY OF THE INVENTION
The present invention provides an improved penetrating tool for pavement breakers as described in U.S. Pat. No. 4,340,255. The tool of the present invention has a flange with a striking surface which extends in the direction of motion of the vehicle. The striking surface is curved so that the closing angle, defined as the difference between the angle of motion and the angle of inclination of that portion of the striking surface in contact with the pavement, is constant throughout the entire stroke of the tool. The constant closing angle should be within the range of about 6°-18°, preferably about 15°.
By providing a constant closing angle along the striking surface of the tool, the required input force to penetrate the material remains constant, as are the reaction forces on the beam. The system can thus be operated at its near optimum mode at all times, without undue concern about wide excursions in the required input and resultant reaction forces. This results in a far more stable and efficient operation, and because the system operates near optimum at all times, its performance is significantly improved.
The novel features which are characteristic of the invention, as to organization and method of operation, together with further objects and advantages thereof will be better understood from the following description considered in connection with the accompanying drawings in which a preferred embodiment of the invention is illustrated by way of example. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only and are not intended as a definition of the limits of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevation view of a pavement breaker incorporating the tool of the present invention;
FIG. 2 is a plan view of the embodiment of FIG. 1;
FIG. 3 is an elevation view of the preferred embodiment of the tool of the present invention;
FIG. 4 is a plan view of the embodiment of FIG. 3;
FIGS. 5A and B are schematic views depicting the operation of the preferred embodiment of the tool of the present invention;
FIG. 6 is a schematic depiction of the angular relationships of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred embodiment 10 of a vertical impact system incorporating the present invention is illustrated generally by way of reference to FIGS. 1 and 2 in combination. Impact system 10 includes a carrier vehicle with a forward frame 12 connected to a rear frame 14 by an articulating joint 16. Hydraulic actuators 17, 18 extend between forward and rear frames 12, 14 to control articulation of the vehicle. The carrier vehicle rides on wheels 20 over a surface 22 which is to receive vertical impact forces for some purpose, such as old pavement to be broken up and removed, existing pavement to be cut for utility work, and the like.
An engine 24 is mounted on rear frame 14, and provides both motive power for the wheels 20 and hydraulic power from a reservoir 26. The operator of the vehicle rides in a control cab 28 projecting forwardly and to one side of the remainder of the vehicle.
A solid, homogeneous resonant beam 30, typically steel, is supported by the carrier vehicle. In the preferred embodiment, resonant beam 30 is approximately 121/2 feet long, and has a resonant frequency of about 45 cycles per second when vibrating transversely about forward and aft nodes spaced inwardly from its ends. While resonating in this fashion, resonant beam 30 has antinodes (locations of maximum amplitude) at its opposite ends and approximately at its center. Pavement penetrating tool 31 depends from the forward end of beam 30.
Resonant beam 30 is supported at its aft node by a shaft 32 which projects through the beam at the location of the aft node (see U.S. Pat. No. 4,320,807). Shaft 32 is supported by a pair of pneumatic tires 34 embedded in the forward frame 12 of the vehicle. Since shaft 32 passes through a node position of beam 30, vibration of the beam at the node position is relatively small (theoretically zero) and the transmission of vibratory forces from the beam to the frame is minimized.
A massive weight 38 is superimposed over beam 30 toward its forward end. Weight 38 is fixed to a bracket 40 which is in turn connected to a member (not shown) which pivots about shaft 32 to control the position of the weight relative to beam 30. An hydraulic cylinder 46 depends from a pin 48 attached to a portion 50 of the forward frame 12, and is fixed to bracket 40. Hydraulic cylinder 46 is of the single acting type, in which the cylinder can be contracted to lift weight 38, but cannot be extended to push down on the weight. Use of such a single acting cylinder allows weight 38 to be raised for transportation of the system, but inhibits the transmission of reaction forces from weight 38 to frame element 50 of the vehicle. Beam 30 is attached to the underside of weight 38 at the forward node of the beam, as discussed in more detail hereinafter.
Beam 30 has an enlarged housing formed in its input end 56, in which is located an eccentric oscillator. A hydraulic motor 60 operated by drive 58 rotates the eccentric oscillator to vibrate the beam at at least near its resonant frequency. Tool 31, depending from the output end of resonant beam 30, is thus driven to penetrate underlying surface 22.
A preferred embodiment of tool 31 is illustrated in more detail by way of reference to FIGS. 3 and 4. Tool 31 includes a shank 62 with forwardly and rearwardly disposed inclined flanges 63, 64. Flanges 63, 64 have mirror image striking surfaces 65, 66 having a complex curved configuration. A flat horizontal surface 68 is located at the base of the tool and is contiguous with striking surfaces 65, 66.
Preferred embodiment 31 of the present invention depicts a cutting type of tool which is quite narrow, having a transverse dimension of about 11/4" at the base and about 3/4" along the flanges. This tool will provide a cutting type of action for the underlying surface, but the present invention could also be adapted to wider tools used to achieve a crushing or breaking action.
As illustrated in FIGS. 5A and B, resonant beam 30 is attached to weight 38 by a link 70 connected to an abutment 72 emanating from the beam at the location of its forward node. When resonant beam 30 is vibrating, the forward portion of the beam, including tool 31 attached thereto, essentially pivots about the location of its forward node, i.e., abutment 72. (The movement of the beam is actually more complex because it is bending, but this fact is insignificant for the purposes of the present discussion.)
The point "a" of a striking surface 65 of tool 31 in instantaneous contact with surface 22 moves in an essentially circular arc centered at abutment 72. Line 73 on FIG. 5 shows the radius of the arc and line 74 shows a perpendicular thereto. Line 74 is thus a tangent to a circle centered at abutment 72 and passing through point "a", and indicates the direction of motion of point "a".
The degree to which striking surface 65 impacts underlying surface 22 depends on the "closing angle", designated "α". The closing angle is the amount by which the angle of inclination of the tool at point "a", represented by a tangent line 76 to surface 65 at point "a", exceeds the direction of motion of the tool as represented by line 74.
Turning to FIG. 6, the angle of motion of the tool, considered an oblique angle from surface 22, is represented by θ. θ is the angular distance measured about "a" from surface 22 to line 74, the direction of motion of the point "a" of the tool. The angle of inclination of the tool, represented by γ, is the oblique angle taken about "a" from surface 22 to line 76, 76 being the tangent to striking surface 65 of the tool at point "a". The difference between γ and θ is α, the closing angle of the tool.
FIG. 5B shows tool 31 further penetrating surface 22 relative to the position shown in FIG. 5A, and the point at which the striking surface 65 contacts surface 22 has moved to point "b". Comparing FIG. 5B with 5A, it is apparent that as striking surface 65 of tool 31 penetrates surface 22, the distance from node 72 to the point at which striking surface 65 contacts surface 22, as represented by line 73', increases. As a result, θ' the angle of motion of point "b", is greater than θ. The object of the present invention is to maintain α constant, and since θ decreases as the point of impact moves outwardly along the tool, γ, the angle of a tangent to the striking surface of the tool, decreases by the same amount.
Referring to FIG. 3, coordinates X and Y are located at the theoretical base of the tool, determined by the point at which striking surfaces 65, 66 would meet if they were not truncated by flat surface 68. In the embodiment shown, the theoretical base of the tool is located 25 inches forward of and 281/4 inches below forward node position 72. The shape of striking surface 65, and mirror image surface 66, is determined by the following table.
______________________________________X Y X Y______________________________________0 0 8 5 5/161/2 7/32 81/2 53/41 15/32 9 6 3/1611/2 23/32 91/2 65/82 1 10 71/821/2 1 5/16 101/2 75/83 15/8 11 81/831/2 1 29/32 111/2 8 23/324 21/4 12 91/441/2 2 9/16 121/2 9 25/325 27/8 13 103/851/2 3 9/32 131/2 11 1/326 3 21/3261/2 4 1/167 4 15/3271/2 47/8______________________________________
In operation, tool 31 of the present invention penetrates surface 22 at a closing angle α. The striking surface 65 of tool 31 is curved so that as the tool penetrates the surface, the closing angle remains constant because of the curvature of the striking tool. As a result, the force required to cut through the surface, and the reaction forces on the beam absorbed by weight 38, are essentially constant.
While a preferred embodiment of the present invention has been illustrated in detail, it is apparent that modifications and adaptations of that embodiment will occur to those skilled in the art. However, it is to be expressly understood that such modifications and adaptations are within the spirit and scope of the present invention, as set forth in the following claims. | An improved penetrating tool for pavement breakers is disclosed. The tool of the present invention has a flange with a striking surface which extends in the direction of motion of the vehicle. The striking surface is curved so that the closing angle, defined as the difference between the angle of motion and the angle of inclination of that portion of the striking surface in contact with the pavement, is constant throughout the entire stroke of the tool. The constant closing angle should be within the range of about 6°-18°, preferably about 15°. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to processes for producing guanosine 5′-diphospho-fucose (hereinafter referred to as “GDP-fucose”) and guanosine 5′-diphospho-4-keto-6-deoxymannose (hereinafter referred to as “GKDM”) GDP-fucose is useful, for example, as a synthetic substrate of complex carbohydrates which are useful, for example, for application to and immunotherapy for the protection against infections by bacteria, viruses and the like and cardiovascular diseases. Also, GKDM is useful as, for example, an intermediate for the production of GDP-fucose.
2. Brief Description of the Background Art
As a process for producing GDP-fucose, a chemical synthesis process ( Carbohyd. Res., 242: 69 (1993)) is known; however, it has disadvantages in terms of stereoselectivity and the supply of a substrate. The processes in which enzymes are used ( Agric. Biol. Chem., 48: 823 (1984), WO 93/08205, and WO 99/09180) are not suitable for large scale production since they use expensive materials. Also, the enzymes require complex purification steps. A process using the activity of a microorganism has been developed (WO 98/12343) and is a useful process; however, it requires further modification for use as an industrial production process. In addition, it is known that the activity of GDP-mannose 4,6-dehydratase as the starting enzyme in the biosynthesis of GDP-fucose from GDP-mannose is inhibited by the final product, GDP-fucose ( Biochim. Biophys. Acta, 117: 79 (1966); FEBS Lett., 412: 126 (1997)).
SUMMARY OF THE INVENTION
An object of the present invention is to provide efficient processes for producing GDP-fucose and GKDM.
This object and others are provided by the present invention, which relates to the following (1) to (18).
(1) A process for producing GDP-fucose, comprising:
allowing GKDM and an enzyme source to be present in an aqueous medium, wherein the enzyme source is a culture broth of a microorganism capable of converting GKDM into GDP-fucose or a treated product of the culture broth;
forming and accumulating GDP-fucose in the aqueous medium; and
recovering the GDP-fucose from the aqueous medium.
(2) A process for producing GDP-fucose, comprising:
allowing a guanosine 5′-triphosphate (hereinafter referred to as “GTP”) precursor, a saccharide and enzyme sources to be present in an aqueous medium, wherein the enzyme sources are a culture broth of a microorganism capable of forming GTP from a GTP precursor or a treated product of the culture broth, and a culture broth of a microorganism capable of forming GKDM from a saccharide and GTP or a treated product of the culture broth;
forming and accumulating GKDM in the aqueous medium;
converting the accumulated GKDM into GDP-fucose using, as an enzyme source, a culture broth of a microorganism capable of converting GKDM into GDP-fucose or a treated product of the culture broth to form and accumulate GDP-fucose in the aqueous medium; and
recovering the GDP-fucose from the aqueous medium.
(3) A process for producing GKDM, comprising:
allowing a GTP precursor, a saccharide and enzyme sources to be present in an aqueous medium, wherein the enzyme sources are a culture broth of a microorganism capable of forming GTP from a GTP precursor or a treated product of the culture broth, and a culture broth of a microorganism capable forming GKDM from a saccharide and GTP or a treated product of the culture broth,
forming and accumulating GKDM in the aqueous medium; and
recovering the GKDM from the aqueous medium.
(4) The process according to (1), (2) or (3), wherein the treated product of the culture broth is selected from the group consisting of a concentrated product of the culture broth, a dried product of the culture broth, cells obtained by centrifuging the culture broth, a dried product of the cells, a freeze-dried product of the cells, a surfactant-treated product of the cells, an ultrasonic wave-treated product of the cells, a mechanical grinding-treated product of the cells, a solvent-treated product of the cells, an enzyme-treated product of the cells, a protein fraction of the cells, an immobilized product of the cells, and an enzyme preparation obtained by extracting from the cells.
(5) The process according to (2) or (3), wherein the GTP precursor is selected from the group consisting of guanine, xanthine, hypoxanthine, guanosine, xanthosine, inosine, guanosine 5′-monophosphate, xanthosine 5′-monophosphate, and inosine 5′-monophosphate.
(6) The process according to (2) or (3), wherein the saccharide is selected from the group consisting of glucose, fructose, and mannose.
(7) The process according to (2) or (3), wherein the microorganism capable of forming GTP from a GTP precursor is selected from microorganisms belonging to the genus Corynebacterium.
(8) The process according to (7), wherein the microorganism is Corynebacterium ammoniagenes.
(9) The process according to (2) or (3), wherein the microorganism capable of forming GKDM from a saccharide and GTP is at least one kind of microorganisms.
(10) The process according to (9), wherein the at least one kind of microorganisms is at least one microorganism selected from microorganisms belonging to the genera Escherichia and Corynebacterium.
(11) The process according to (10), wherein the microorganism belonging to the genus Escherichia is Escherichia coli.
(12) The process according to (10), wherein the microorganism belonging to the genus Corynebacterium is Corynebacterium ammoniagenes.
(13) The process according to (2) or (3), wherein the microorganism capable of forming GKDM from a saccharide and GTP is a microorganism having a strong activity of at least one enzyme selected from the group consisting of glucokinase (hereinafter referred to as “glk”), phosphomannomutase (hereinafter referred to as “manB”), mannose 1-phosphate guanylyltransferase (hereinafter referred to as “manC”), phosphoglucomutase (hereinafter referred to as “pgm”), phosphofructokinase (hereinafter referred to as “pfk”), and GDP-mannose 4,6-dehydratase (hereinafter referred to as “gmd”).
(14) The process according to (13), wherein the microorganism is at least one microorganism having a recombinant DNA comprising a vector and a DNA fragment containing at least one gene selected from the group consisting of a glk-encoding gene, a manB-encoding gene, a manC-encoding gene, a pgm-encoding gene, a pfk-encoding gene, and a gmd-encoding gene.
(15) The process according to (14), wherein the glk-encoding gene, the manB-encoding gene, the manC-encoding gene, the pgm-encoding gene, the pfk-encoding gene or the gmd-encoding gene is a gene derived from Escherichia coli.
(16) The process according to (1) or (2), wherein the microorganism capable of converting GKDM into GDP-fucose is a microorganism having strong GKDM epimerase/reductase (hereinafter referred to as “wcaG”) activity.
(17) The process according to (16), wherein the microorganism is a microorganism having a recombinant DNA comprising a vector and a DNA fragment containing a wcaG-encoding gene.
(18) The process according to (17), wherein the wcaG-encoding gene is derived from Escherichia coli.
BRIEF EXPLANATION OF THE DRAWINGS
FIG. 1 shows construction steps of a plasmid pNK11 capable of expressing glk, manB and manC.
FIG. 2 shows construction steps of a plasmid pGE19 capable of expressing gmd.
FIG. 3 shows construction steps of a plasmid pGE8 capable of expressing wcaG.
DETAILED DESCRIPTION OF THE INVENTION
This application is based on Japanese application No. Hei 11-225889 filed on Aug. 10, 1999, the entire contents of which is incorporated hereinto by reference.
In order to achieve the above and other objects, the present inventors have conducted intensive studies, and found that the inhibition of GDP-mannose 4,6-dehydratase activity by GDP-fucose can unexpectedly be avoided, and therefore GDP-fucose can be formed efficiently, by forming and accumulating GKDM, (a precursor of GDP-fucose), and then converting the thus accumulated GKDM into GDP-fucose.
The process is preferably conducted in the culture broth of a microorganism capable of forming GTP from a GTP precursor or a treated product of the culture broth. Any microorganism can be used so long as it is a microorganism having such an ability. Appropriate GTP precursors are well-known, and include those described later. Examples of such microorganisms include those belonging to the genus Escherichia and the genus Corynebacterium.
Examples of the microorganisms belonging to the genus Escherichia include Escherichia coli and the like. Examples of the microorganisms belonging to the genus Corynebacterium include Corynebacterium ammoniagenes and the like. Specific examples include Corynebacterium ammoniagenes ATCC 21170 and the like.
Also, the process is preferably conducted in the culture broth of a microorganism capable of forming GKDM from a saccharide and GTP or a treated product of the culture broth. Appropriate saccharides are also well-known, and include those described later. Examples of such microorganisms include those having a strong activity of at least one enzyme selected from the group consisting of glk, manB, manC, pgm, pfk and gmd. The above microorganisms having a strong enzyme activity mean microorganisms having an activity of at least one enzyme selected from the group consisting of, for example, glk, manB, manC, pgm, pfk and gmd which has been improved from the activity of a parent strain. The parent strain means a microorganism used as the origin in the construction of a variant, a cell fusion strain, a transductant or a recombinant strain. The microorganisms having an activity of at least one enzyme selected from the above enzymes which has been improved from the activity of the parent strain may be any of a variant, a cell fusion strain, a transductant and a recombinant strain.
Examples thereof include microorganisms belonging to the genus Escherichia and the genus Corynebacterium . Preferred examples include Escherichia coli and Corynebacterium ammoniagenes.
Additionally, a transformant in which an activity of at least one enzyme selected from glk, manB, manC, pgm, pfk and gmd is improved by recombinant DNA techniques can also be used. Examples thereof include Escherichia coli NM522 having a recombinant DNA (pNK11) containing a glk gene derived from Escherichia coli ( J. Bacterial., 179: 1298 (1997)), Escherichia coli NM522 having a recombinant DNA (pNK11) containing a manB gene derived from Escherichia coli ( J. Bacteriol., 178: 4885 (1996)), Escherichia coli NM522 having a recombinant DNA (pNK11) containing a manC gene derived from Escherichia coli ( J. Bacteriol., 178: 4885 (1996)), Escherichia coli NM522 having a recombinant DNA (pNT55) containing a pgm gene derived from Escherichia coli ( J. Bacteriol., 176: 1298 (1994)) (WO 98/12343), Escherichia coli NM522 having a recombinant DNA (pNT55) containing a pfkB gene derived from Escherichia coli ( Gene, 28: 337 (1984)) (WO 98/12343), Escherichia coli NM522 having a recombinant DNA (pGE19) containing a gmd gene derived from Escherichia coli ( J. Bacteriol., 178: 4885 (1996)), and the like.
When a microorganism is capable of forming GTP from a GTP precursor and is also capable of forming GKDM from a saccharide and GTP simultaneously, GKDM can then be formed by the microorganism from a GTP precursor and a saccharide. Also, in the case of a microorganism which has only a part of the activities necessary for forming GKDM from a saccharide and GTP in one strain, GKDM can be formed by appropriately combining at least two microorganisms.
Any microorganism can be used as the microorganism capable of converting GKDM into GDP-fucose used in the present invention, so long as it has such a converting activity. For example, a microorganism having a strong wcaG activity can be used.
Specifically, a microorganism belonging to the genus Escherichia or the genus Corynebacterium , such as Escherichia coli, Corynebacterium ammoniagenes , or the like, can be exemplified.
Furthermore, a transformant in which activities of GKDM epimerase/reductase are improved by recombinant DNA techniques can also be used. Examples thereof include Escherichia coli NM522 having a recombinant DNA (pGE8) containing an Escherichia coli wcaG gene ( J. Bacteriol., 178: 4885 (1996)).
In the above production of GDP-fucose and GKDM using recombinant DNA techniques, various processes related to genetic recombination, such as isolation and purification of a plasmid DNA from a microorganism, digestion of the plasmid DNA with restriction enzymes, isolation and purification of the digested DNA fragment, enzymatic ligation of the DNA fragments, transformation using a recombinant DNA, and the like, can be carried out in accordance with known processes (e.g., Molecular Cloning, A Laboratory Manual, Second Edition , Cold Spring Harbor Laboratory Press (1989) (hereinafter referred to as “ Molecular Cloning, Second Edition ”) and Current Protocols in Molecular Biology , John Wiley & Sons (1987-1997) (hereinafter referred to as “ Current Protocols in Molecular Biology ”)). Also, a polymerase chain reaction (hereinafter referred to as “PCR”) can be carried out in accordance with a known process ( PCR Protocols , Academic Press (1990)).
A gene related to the formation of GDP-fucose or GKDM can be expressed in a host by making a DNA fragment containing the gene into a DNA fragment having an appropriate length containing the gene with restriction enzymes or by the PCR, inserting the resulting fragment into the downstream of the promoter of an appropriate expression vector, and then introducing the DNA-inserted expression vector into a host cell suitable for the expression vector.
Any of bacteria, yeast and the like can be used as the host cell, so long as it can express the gene of interest.
Examples of the expression vector include those capable of replicating autonomously in the above-described host cell or capable of being integrated into chromosome, and containing a promoter at the position where the gene of interest can be transcribed.
When a prokaryote, such as a bacterium or the like, is used as the host cell, it is preferred that the gene expression vector can replicate autonomously in the prokaryote and is a recombinant DNA which is constructed from a promoter, a ribosome binding sequence, a DNA of interest and a transcription termination sequence. It may contain a gene which controls the promoter.
Examples of the expression vector include pKK223-3 and pGEX-2T (both manufactured by Amersham Pharmacia Biotech Co.), pSE280 (manufactured by Invitrogen Co.), pGEMEX-1 (manufactured by Promega Co.), pQE-30 (manufactured by Quiagen Co.), pET-3 (manufactured by Novagen Co.), pKYP10 (Japanese Published Unexamined Patent Application No. 110600/83), pKYP200 ( Agric. Biol. Chem., 48: 669 (1984)), pLSA1 ( Agric. Biol. Chem., 53: 277 (1989)), pGEL1 ( Proc. Natl. Acad. Sci., USA, 82: 4306 (1995)), pBluescript II SK+ (manufactured by Stratagene Co.), pBluescript II SK− (manufactured by Stratagene Co.), pTrS30 (prepared from Escherichia coli JM109/pTrS30 (FERM BP-5407)), pTrS32 (prepared from Escherichia coli JM109/pTrS32 (FERM BP-5408)), pUC19 ( Gene, 33: 103 (1985)), pSTV28 (manufactured by Takara Shuzo Co., Ltd.), pUC118 (manufactured by Takara Shuzo Co., Ltd.), pPAC31 (WO 98/12343), and the like.
Any promoter can be used, so long as it can function in host cells, such as Escherichia coli and the like. Examples thereof include promoters derived from a bacterium or phage, such as trp promoter (Ptrp), lac promoter (Plac) P L promoter (P L ), P R promoter, P SE promoter, and the like, SPO1 promoter, SPO2 promoter, penP promoter, and the like. Further examples include artificially designed and modified promoters, such as a promoter prepared by connecting two Ptrp's in series, tac promoter, lac T7 promoter, and let I promoter.
It is preferred to use a plasmid in which the space between the Shine-Dalgarno sequence which is a ribosome binding sequence and the initiation codon is controlled at an appropriate distance (e.g., 6 to 18 bases).
In the recombinant DNA of the present invention, the transcription termination sequence is not always necessary for the expression of the DNA of interest; however, it is preferred to arrange the transcription termination sequence just below the structural gene.
Examples of the prokaryote include microorganisms belonging to the genus Escherichia, Serratia, Bacillus, Brevibacterium, Corynebacterium, Microbacterium, Pseudomonas , and the like. Specific examples include Escherichia coli XL1-Blue, Escherichia coli XL2-Blue, Escherichia coli DH1 , Escherichia coli MC1000 , Escherichia coli W1485 , Escherichia coli NM522 , Escherichia coli JM109 , Escherichia coli HB101 , Escherichia coli No. 49 , Escherichia coli W3110 , Escherichia coli NY49 , Serratia ficaria, Serratia fonticola, Serratia liquefaciens, Serratia marcescens, Bacillus subtilis, Bacillus amyloliquefaciens, Brevibacterium immariophilum ATCC 14068 , Brevibacterium saccharolyticum ATCC 14066 , Corynebacterium ammoniagenes, Corynebacterium glutamicum ATCC 13032 , Corynebacterium glutamicum ATCC 14067 , Corynebacterium glutamicum ATCC 13869 , Corynebacterium acetoacidophilum ATCC 13870 , Microbacterium ammoniaphilum ATCC 15354 , Pseudomonas sp. D-0110, and the like.
As the process for introducing a recombinant DNA, any process can be used, so long as it is a process for introducing the DNA into the host cell, such as a process using a calcium ion ( Proc. Natl. Acad. Sci., USA, 69: 2110 (1972)), a protoplast process (Japanese Published Unexamined Patent Application No. 248394/88), an electroporation process ( Nucleic Acids Research, 16: 6127 (1988)), and the like.
When a yeast strain is used as the host cell, examples of used expression vector include YEp13 (ATCC 37115), YEp24 (ATCC 37051), YEp50 (ATCC 37419), pHS19, pHS15, and the like.
Any promoter can be used, so long as it can function in the yeast strain. Examples thereof include PH05 promoter, PGK promoter, GAP promoter, ADH promoter, gal 1 promoter, gal 10 promoter, heat shock polypeptide promoter, MFα1 promoter, CUP 1 promoter, and the like.
Examples of the host cell include yeast strains belonging to the genus Saccharomyces, Schizosaccharomyces, Kluyveromyces, Trichosporon, Schwanniomyces, Pichia, Candida , and the like. Specific examples include Saccharomyces cerevisiae, Schizosaccharomyces pombe, Kluyveromyces lactis, Trichosporon pullulans, Schwanniomyces alluvius, Pichia pastoris, Candida utilis , and the like.
As the process for introducing the recombinant DNA, any process can be used, so long as it is a process for introducing the DNA into yeast. Examples thereof include an electroporation process ( Methods in Enzymol., 194: 182 (1990)), a spheroplast process ( Proc. Natl. Acad. Sci. USA, 81: 4889 (1984)), a lithium acetate process ( J. Bacteriol., 153: 163 (1983)), and the like.
Culturing of the transformant of the present invention in a medium can be carried out in accordance with a process generally used for culturing a host.
As the medium for culturing the transformant obtained using a prokaryote, such as Escherichia coli or the like, or a eucaryote, such as yeast or the like, as the host, any one of natural media and synthetic media can be used, so long as it contains a carbon source, a nitrogen source, inorganic salts and the like which can be assimilated by the organism and can perform culturing of the transformant efficiently.
Any material which can be assimilated by the organism can be used as the carbon source. Examples thereof include carbohydrates (e.g., glucose, fructose, sucrose, molasses containing them, starch, starch hydrolysate, etc.), organic acids (e.g., acetic acid, propionic acid, etc.), alcohols (e.g., ethanol, propanol, etc.), and the like.
Examples of the nitrogen source include ammonia, ammonia salts of inorganic or organic acids (e.g., ammonium chloride, ammonium sulfate, ammonium acetate, ammonium phosphate, etc.), other nitrogen-containing compounds, peptone, meat extract, yeast extract, corn steep liquor, casein hydrolysate, soybean meal, soybean meal hydrolysate, various fermented cells and digests thereof, and the like.
Examples of inorganic materials used in the medium include potassium dihydrogen phosphate, dipotassium hydrogen phosphate, magnesium phosphate, magnesium sulfate, sodium chloride, ferrous sulfate, manganese sulfate, copper sulfate and calcium carbonate.
The culturing is carried out generally under aerobic conditions, such as shaking culture, submerged aeration agitation culture, and the like. The culturing temperature is preferably from 15 to 40° C., and the culturing time is generally from 5 hours to 7 days. During the culturing, the medium pH is controlled at from 3.0 to 9.0. The pH is adjusted by an inorganic or organic acid, an alkali solution, urea, calcium carbonate, ammonia, or the like.
In addition, antibiotics, such as ampicillin and chloramphenicol, and the like, may be optionally added to the medium during culturing.
When a microorganism transformed with an expression vector in which an inducible promoter is used as the promoter is cultured, an inducer may be optionally added to the medium. For example, when a microorganism transformed with an expression vector using lac promoter is cultured, isopropyl-β-D-thiogalactopyranoside may be added to the medium; and when a microorganism transformed with an expression vector using trp promoter is cultured, indole acrylate may be added.
When at least two microorganisms are used in the process of the present invention, such microorganisms may be separately cultured to use the respective culture broths, or they may be simultaneously inoculated into a single culture vessel to carry out mixture culturing and then the resulting culture broth is used. Alternatively, during or after completion of the culturing of any one of the microorganisms, the remaining microorganism is inoculated and cultured and the resulting culture broth is used.
A microbial culture broth obtained by the culturing or a treated product of the culture broth after its various treatment can be used as an enzyme source in the process of the present invention in an aqueous medium.
Examples of the treated product of the culture broth include a concentrated product of the culture broth, a dried product of the culture broth, cells obtained by centrifuging the culture broth, a dried product of the cells, a freeze-dried product of the cells, a surfactant-treated product of the cells, an ultrasonic wave-treated product of the cells, a mechanical grinding-treated product of the cells, a solvent-treated product of the cells, an enzyme-treated product of the cells, a protein fraction of the cells, an immobilized product of the cells, an enzyme preparation obtained by extracting from the cells, and the like.
The microorganism in the process of the present invention is used at an amount of from 1 to 500 g/l, preferably from 5 to 300 g/l, as wet cells. Also, when the formation reaction is carried out simultaneously using at least two microorganisms, the amount of the total wet cells of the microorganisms in an aqueous medium is from 2 to 500 g/l, preferably from 10 to 400 g/l.
Examples of the GTP precursor used in the process of the present invention include guanine, xanthine, hypoxanthine, guanosine, xanthosine, inosine, guanosine 5′-monophosphate, xanthosine 5′-monophosphate, inosine 5′-monophosphate, and the like. The precursor which can be used include a purified compound, a salt of the precursor, and a culture broth containing the precursor produced by fermentation of a microorganism or the precursor partially purified from the culture broth, so long as the contaminants do not inhibit the reaction. The GTP precursor is used at a concentration of from 0.1 mM to 1.0 M, preferably from 0.01 to 0.5 M.
Examples of the saccharide used in the process of the present invention include glucose, fructose, mannose, derivatives thereof, and the like. The saccharide may be used as a purified product or a material containing the same, so long as the contaminants do not inhibit the reaction. The saccharide may be added in a lump at the time of starting of the reaction, or dividually or continuously during the reaction. The saccharide used at a concentration of from 0.1 mM to 2.0 M.
In the process of the present invention, an energy donor, a coenzyme, a phosphate ion, a magnesium ion, a chelating agent (e.g., phytic acid, etc.), a surfactant and an organic solvent may be optionally added.
Any compound can be used as the energy donor, so long as it promotes the formation. Examples thereof include carbohydrates (e.g., glucose, fructose, sucrose, lactose, maltose, mannitol, sorbitol, etc.), organic acids (e.g., pyruvic acid, lactic acid, acetic acid, etc.), amino acids (e.g., glycine, alanine, aspartic acid, glutamic acid, etc.), molasses, starch hydrolysate, and the like. The energy donor is used at a concentration of from 1.0 mM to 2.0 M.
Examples of the phosphate ion include orthophosphoric acid, pyrophosphoric acid, tripolyphosphoric acid, polyphosphoric acid, metaphosphoric acid, inorganic phosphates (e.g., potassium dihydrogenphosphate, dipotassium hydrogenphosphate, sodium dihydrogenphosphate, disodium hydrogenphosphate, etc.), and the like. The phosphate ion is used at a concentration of from 1.0 mM to 1.0 M.
Examples of the magnesium ion include inorganic magnesium salts (e.g., magnesium sulfate, magnesium nitrate, magnesium chloride, etc.), organic magnesium salts (e.g., magnesium citrate, etc.), and the lie. The magnesium ion is generally used at a concentration of from 1 to 100 mM.
Any surfactant can be used, so long as it can promote the formation. Examples thereof include nonionic surfactants (for example, polyoxyethylene octadecylamine (e.g., Nymeen S-215, manufactured by NOF CORPORATION), etc), cationic surfactants (for example, cetyltrimethylammonium bromide, alkyldimethyl benzylammonium chloride (e.g., Cation F2-40E, manufactured by NOF CORPORATION), etc.), anionic surfactants (for example, lauroyl sarcosinate, etc.), tertiary amines (for example, alkyldimethylamine (e.g., Tertiary Amine FB, manufactured by NOF Corporation), etc.), and the like, which may be used alone or as a mixture of at least two thereof. The surfactant is generally used at a concentration of from 0.1 to 50 g/l.
Examples of the organic solvent include xylene, toluene, aliphatic alcohol, acetone, ethyl acetate, and the like. The organic solvent is generally used at a concentration of from 0.1 to 50 ml/l.
Examples of the aqueous medium used in the process of the present invention include water, buffers (e.g., buffers of phosphate, carbonate, acetate, borate, citrate, Tris, etc.), alcohols (e.g., methanol, ethanol, etc.), esters (e.g., ethyl acetate, etc.), ketones (e.g., acetone, etc.), amides (e.g., acetamide, etc.), and the like. Alternatively, a culture medium of a microorganism may be used as the aqueous medium.
The process of the present invention is carried out in the aqueous medium for 1 to 96 hours at pH 5 to 10, preferably pH 6 to 8 and at a temperature of 20 to 50° C.
The GDP-fucose and GKDM formed in the aqueous medium can be determined using HPLC or the like in accordance with the process described in WO 98/12343.
The GDP-fucose and GKDM formed in the aqueous medium can be recovered in accordance with a usual process using activated carbon or an ion exchange resin ( Carbohyd. Res., 242: 69 (1993)).
Preferred embodiments of the present invention are shown in the following Examples. However, the present invention is not limited thereto.
EXAMPLE 1
Construction of a Strain Expressing glk, manB, manC, pgm and pfkB
A DNA primer having the nucleotide sequence of SEQ ID NO:1 and a DNA primer having the nucleotide sequence of SEQ ID NO:2 were synthesized using a 8905 type DNA synthesizer manufactured by Perceptive Biosystems Co.
Using these synthetic DNA primers, PCR was carried out using a glk gene-containing plasmid pNT46 (WO 98/12343) DNA as a template. The PCR was carried out using 40 μl of a reaction solution containing 1 ng of pNT46 DNA, 0.5 μM of each primer, 2.5 units of Pfu DNA polymerase (manufactured by Stratagene Co.), 4 μl of ×10 buffer for Pfu DNA polymerase (manufactured by Stratagene Co.) and 200 μM of each deoxyNTP, by repeating a cycle of 94° C. for 1 minute, 42° C. for 2 minutes and 72° C. for 3 minutes 30 times.
A 1/10 volume of the reaction solution was subjected to agarose gel electrophoresis to confirm amplification of the fragment of interest and then the remaining reaction solution was mixed with the same volume of TE (10 mM Tris-HCl (pH 8.0) and 1 mM EDTA)-saturated phenol/chloroform (1 vol/1 vol).
After centrifugation of the mixture, the thus obtained upper layer was mixed with two volumes of cold ethanol, and the mixture was allowed to stand at −80° C. for 30 minutes. The resulting solution was centrifuged to obtain a precipitate of DNA.
The precipitate of DNA was dissolved in 20 μl of TE. Using 5 μl of the resulting solution, the DNA was digested with restriction enzymes BGlII and SalI, the resulting DNA fragments were separated by agarose gel electrophoresis, and then a fragment of 1.3 kb was recovered using Gene Clean II Kit.
A manB and manC expression plasmid pNK7 (WO 98/12343) (0.2 μg) was digested with restriction enzymes BamHI and SalI, the DNA fragments were separated by agarose gel electrophoresis, and then a fragment of 8.2 kb was recovered in the same manner.
Using a ligation kit, the fragments of 1.3 kb and 8.2 kb were subjected to a ligation reaction at 16° C. for 16 hours. Using the ligation reaction solution, Escherichia coli NM522 was transformed in accordance with the known process described above, and the resulting transformants were spread on an LB agar medium containing 50 μg/ml ampicillin, followed by culturing overnight at 30° C.
Plasmids were extracted from the thus grown transformant colonies in accordance with the known process described above to obtain a plasmid pNK11 capable of expressing glk, manB and manC. The structure of this plasmid was confirmed by restriction enzyme digestion (FIG. 1 ). In FIG. 1 , symbols “Amp r ” and “cI857” represent an ampicillin-resistant gene and cI857 repressor, respectively.
Using the thus obtained plasmid pNK11 , Escherichia coli NM522/pNT55 (WO 98/12343) was transformed in accordance with the known process, and the resulting transformants were spread on an LB agar medium containing 50 μg/ml ampicillin and 10 μg/ml chloramphenicol, followed by culturing overnight at 30° C. By selecting the thus grown transformants, Escherichia coli NM522/pNK11/pNT55 as a strain capable of simultaneously expressing glk, manB, manC, pgm and pfkB was obtained.
EXAMPLE 2
Construction of a Strain Expressing Escherichia coli gmd
Escherichia coli W3110 (ATCC 27325) was cultured by the process described in Current Protocols in Molecular Biology , and then chromosomal DNA of the microorganism was isolated and purified.
Using DNAs synthesized by the 8905 type DNA synthesizer manufactured by Perceptive Biosystems Co., having the nucleotide sequences of SEQ ID NOs:3 and 4, respectively, as primers, PCR was carried out in accordance with the process described in Example 1 using 0.1 μg of the chromosomal DNA of Escherichia coli W3110 (ATCC 27325) as a template.
A 1/10 volume of the reaction solution was subjected to agarose gel electrophoresis to confirm amplification of the fragment of interest, and then the remaining reaction solution was mixed with the same volume of TE-saturated phenol/chloroform.
After centrifugation of the mixture, the thus obtained upper layer was mixed with two volumes of cold ethanol, and the mixture was allowed to stand at −80° C. for 30 minutes. The resulting solution was centrifuged to obtain a precipitate of DNA.
The precipitate of DNA was dissolved in 20 μl of TE. Using 5 μl of the resulting solution, the DNA was digested with restriction enzymes HindIII and XbaI, the resulting DNA fragments were separated by agarose gel electrophoresis, and then a DNA fragment of 1.1 kb was recovered using Gene Clean II Kit.
Using DNA preparations synthesized by the 8905 type DNA synthesizer manufactured by Perceptive Biosystems Co., having the nucleotide sequences of SEQ ID NOs:5 and 6, respectively, as primers, PCR was carried out in accordance with the process described in Example 1 using the DNA of a trp promoter-containing plasmid pNT54 (WO 98/12343) as a template.
A 1/10 volume of the reaction solution was subjected to agarose gel electrophoresis to confirm amplification of the fragment of interest, and then the remaining reaction solution was mixed with the same volume of TE-saturated phenol/chloroform.
After centrifugation of the mixture, the thus obtained upper layer was mixed with two volumes of cold ethanol, and the mixture was allowed to stand at −80° C. for 30 minutes. The resulting solution was centrifuged to obtain a precipitate of DNA, and the precipitate of DNA was dissolved in 20 μl of TE.
Using 5 μl of the resulting solution, the DNA was digested with restriction enzymes EcoRI and XbaI, the resulting DNA fragments were separated by agarose gel electrophoresis, and then a DNA fragment of 0.4 kb was recovered in the same manner.
After 0.2 μg of pBluescriptII SK+ DNA was digested with restriction enzymes EcoRI and HindIII, the DNA fragments were separated by agarose gel electrophoresis, and then a DNA fragment of 3.0 kb was recovered in the same manner.
Using a ligation kit, the fragments of 1.1 kb, 0.4 kb and 3.0 kb were subjected to a ligation reaction at 16° C. for 16 hours.
Using the ligation reaction solution, the Escherichia coli NM522 was transformed in accordance with the known process described above, and the resulting transformants were spread on the LB agar medium containing 50 μg/ml ampicillin, followed by culturing overnight at 30° C.
Plasmids were extracted from the thus grown transformant colonies in accordance with the known process described above to obtain an expression plasmid pGE19. The structure of this plasmid was confirmed by restriction enzyme digestion (FIG. 2 ).
EXAMPLE 3
Construction of a Strain Expressing Escherichia coli wcaG
Using DNA preparations synthesized by the 8905 type DNA synthesizer manufactured by Perceptive Biosystems Co., having the nucleotide sequences of SEQ ID NOs:7 and 8, respectively, as primers, PCR was carried out in accordance with the process described in Example 1 using the chromosomal DNA of Escherichia coli W3110 (ATCC 27325) as a template.
A 1/10 volume of the reaction solution was subjected to agarose gel electrophoresis to confirm amplification of the fragment of interest, and then the remaining reaction solution was mixed with the same volume of TE-saturated phenol/chloroform.
After centrifugation of the mixture, the thus obtained upper layer was mixed with two volumes of cold ethanol, and the mixture was allowed to stand at −80° C. for 30 minutes. The resulting solution was centrifuged to obtain a precipitate of DNA, and the precipitate of DNA was dissolved in 20 μl of TE. Using 5 μl of the resulting solution, the DNA was digested with restriction enzymes ClaI and XhoI, the resulting DNA fragments were separated by agarose gel electrophoresis, and then a DNA fragment of 1.0 kb was recovered using Gene Clean II Kit.
After 0.2 μg of pPAC31 DNA was digested with restriction enzymes ClaI and SalI was digested, the DNA fragments were separated by agarose gel electrophoresis, and then a DNA fragment of 5.2 kb was recovered in the same manner.
Using a ligation kit, the fragments of 1.0 kb and 5.2 kb were subjected to a ligation reaction at 16° C. for 16 hours.
Using the ligation reaction solution, the Escherichia coli NM522 was transformed in accordance with the known process described above, and the resulting transformants were spread on the LB agar medium containing 50 μg/ml ampicillin, followed by culturing overnight at 30° C.
Plasmids were extracted from the thus grown transformant colonies in accordance with the known process described above to obtain an expression plasmid pGE8. The structure of this plasmid was confirmed by restriction enzyme digestion (FIG. 3 ).
EXAMPLE 4
Production of GKDM
The Escherichia coli NM522/pNK11/pNT55 obtained in Example 1 was inoculated into a 1 L baffled conical flask containing 125 ml of LB medium supplemented with 50 μ/ml ampicillin and 10 μg/ml chloramphenicol, followed by culturing at 28° C. and at 220 rpm for 17 hours. The resulting culture broth (125 ml) was inoculated into a 5 L culture vessel containing 2.5 L of a liquid medium (pH not adjusted) composed of 10 g/l glucose, 12 g/l bactotryptone (manufactured by Difco Co.), 24 g/l yeast extract (manufactured by Difco Co.), 2.3 g/l KH 2 PO 4 , 12.5 g/l K 2 HPO 4 and 50 μg/ml ampicillin, followed by culturing at 30° C. for 4 hours under conditions of 600 rpm and 2.5 L/minute aeration, and further culturing at 40° C. for 3 hours. During the culturing, the medium pH was maintained at 7.0 using 28% aqueous ammonia. Also, glucose was added during the culturing when necessary. The resulting culture broth was centrifuged to obtain wet cells. Since the wet cells can be preserved at −20° C. as occasion demands, it was able to use them by thawing prior to use.
The Escherichia coli NM522/pGE19 obtained in Example 2 was inoculated into a 1 L baffled conical flask containing 125 ml of LB medium supplemented with 50 μ/ml ampicillin, followed by culturing at 28° C. and at 220 rpm for 17 hours. The resulting culture broth (125 ml) was inoculated into a 5 L culture vessel containing 2.5 L of a liquid medium (pH not adjusted) composed of 10 g/l glucose, 12 g/l Bactotryptone (manufactured by Difco Co.), 24 g/l yeast extract (manufactured by Difco Co.), 2.3 g/l KH 2 PO 4 , 12.5 g/l K 2 HPO 4 and 50 μg/ml ampicillin, followed by culturing at 37° C. for 6 hours under conditions of 600 rpm and 2.5 L/minute aeration. During the culturing, the medium pH was maintained at 7.0 using 28% aqueous ammonia. Also, glucose was added during the culturing when necessary. The resulting culture broth was centrifuged to obtain wet cells. Since the wet cells can be preserved at −20° C. as occasion demands, it was able to use them by thawing prior to use.
Corynebacterium ammoniagenes ATCC 21170 was inoculated into a 300 ml baffled conical flask containing 25 ml of a liquid medium composed of 50 g/l glucose, 10 g/l polypeptone (manufactured by Nihon Pharmaceutical Co., Ltd.), 10 g/l yeast extract (manufactured by Oriental Yeast Co., Ltd.), 5 g/l urea, 5 g/l (NH 4 ) 2 SO 4 , 1 g/l KH 2 PO 4 , 3 g/l K 2 HPO 4 , 1 g/l MgSO 4 .7H 2 O, 0.1 g/l CaCl 2 .2H 2 O, 10 mg/l FeSO 4 .7H 2 O, 10 mg/l ZnSO 4 .7H 2 O, 20 mg/l MnSO 4 .4˜6H 2 O, 20 mg/l L-cysteine, 10 mg/l calcium D-pantothenate, 5 mg/l vitamin B 1 , 5 mg/l nicotinic acid and 30 μg/l biotin (adjusted to pH 7.2 with 10 N NaOH), followed by culturing at 28° C. and at 220 rpm for 24 hours.
The resulting culture broth (20 ml) was inoculated into a 2 L baffled conical flask containing 250 ml of a liquid medium having the same composition, followed by culturing at 28° C. and at 220 rpm for 24 hours. The thus obtained culture broth was used as a seed culture broth.
The seed culture broth (250 ml) was inoculated into a 5 L culture vessel containing 2.25 L of a liquid medium composed of 150 g/l glucose, 5 g/l meat extract (manufactured by Kyokuto Pharmaceutical Industrial Co., Ltd.), 10 g/l KH 2 PO 4, 10 g/l K 2 HPO 4 , 10 g/l MgSO 4 .7H 2 O, 0.1 g/l CaCl 2 .2H 2 O, 20 mg/l FeSO 4 .7H 2 O, 10 mg/l ZnSO 4 .7H 2 O, 20 mg/l MnSO 4 .4˜6H 2 O (separate sterilization), 15 mg/ml β-alanine (separate sterilization), 20 mg/l L-cysteine, 100 μg/l biotin, 2 g/l urea and 5 mg/l vitamin B 1 (separate sterilization) (adjusted to pH 7.2 with 10 N NaOH), followed by culturing at 32° C. for 24 hours under conditions of 600 rpm and 2.5 L/minute aeration. During the culturing, the medium pH was maintained at 6.8 using 28% aqueous ammonia.
The resulting culture broth was centrifuged to obtain wet cells. Since the wet cells can be preserved at −20° C. as occasion demands, it was able to use them by thawing prior to use.
A reaction solution of 25 g/l of the above Escherichia coli NM522/pNK11/pNT55 wet cells, 15 g/l of the above Escherichia coli NM522/pGE19 wet cells, 150 g/l of the above Corynebacterium ammoniagenes ATCC 21170 wet cells, 60 g/l fructose, 30 g/l mannose, 20 g/l GMP, 25 g/l KH 2 PO 4 , 5 g/l MgSO 4 .7H 2 O, 5 g/l phytic acid, 4 g/l Nymeen S-215 and 10 ml/l xylene was put into a 200 ml beaker, and the reaction solution was stirred (900 rpm) using a magnetic stirrer to carry out the reaction at 32° C. for 12 hours. During the reaction, the pH of the reaction solution was maintained at 7.2 using 4 N NaOH, and fructose and KH 2 PO 4 were added when necessary.
After completion of the reaction, the reaction product was analyzed by HPLC to confirm that 18.6 g/l (29.4 mM) of GKDM (2Na salt) was formed and accumulated in the reaction solution.
EXAMPLE 5
Production of GDP-fucose
The Escherichia coli NM522/pNK11/pNT55 obtained in Example 1 was cultured by the process described in Example 4, followed by centrifuging to obtain wet cells.
The Escherichia coli NM522/pGE19 obtained in Example 2 was cultured by the process described in Example 4, followed by centrifuging to obtain wet cells.
The Escherichia coli NM522/pGE8 obtained in Example 3 was cultured by a process similar to the Escherichia coli NM522/pNK11/pNT55 described in Example 4 except for adding ampicillin only instead of adding ampicillin and chloramphenicol, followed by centrifuging to obtain wet cells.
The Corynebacterium ammoniagenes ATCC 21170 was cultured by the process described in Example 4, followed by centrifuging to obtain wet cells.
Since the wet cells can be preserved at −20° C. as occasion demands, it was able to use them by thawing prior to use.
A reaction solution (30 ml) of 25 g/l of the above Escherichia coli NM522/pNK11/pNT55 wet cells, 15 g/l of the above Escherichia coli NM522/pGE19 wet cells, 150 g/l of the above Corynebacterium ammoniagenes ATCC 21170 wet cells, 60 g/l fructose, 30 g/l mannose, 30 g/l GMP, 25 g/l KH 2 PO 4 , 5 g/l MgSO 4 .7H 2 O, 5 g/l phytic acid, 4 g/l Nymeen S-215 and 10 ml/l xylene was put into a 200 ml beaker, and the reaction solution was stirred (900 rpm) using a magnetic stirrer to carry out the reaction at 32° C. for 12 hours. After 12 hours of the reaction, the Escherichia coli NM522/pGE8 wet cells were added to give a concentration of 15 g/l, and the reaction was continued for 10 hours. During the reaction, the pH of the reaction solution was maintained at 7.2 using 4 N NaOH, and fructose and KH 2 PO 4 were added when necessary.
After completion of the reaction, the reaction product was analyzed by HPLC to confirm that 14.0 g/l GDP-fucose was formed and accumulated in the reaction solution.
When the reaction was carried out for 22 hours by adding the Escherichia coli NM522/pGE8 (15 g/l) wet cells at the time of starting of the reaction, the amount of the accumulated GDP-fucose (2Na salt) was 3.7 g/l (5.9 mM).
While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skill in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof. | Processes for producing GDP-fucose, comprising allowing GKDM and a culture broth of a microorganism capable of converting GKDM into GDP-fucose to be present in an aqueous medium, forming and accumulating GDP-fucose therein, and recovering the GDP-fucose therefrom; or comprising allowing a GTP precursor, a saccharide, a culture broth of a microorganism capable of forming GTP from a GTP precursor, and a culture broth of a microorganism capable of forming GKDM from a saccharide and GTP to be present in an aqueous medium, forming and accumulating GKDM therein, converting the accumulated GKDM into GDP-fucose using as a culture broth of a microorganism capable of converting GKDM into GDP-fucose to form and accumulate GDP-fucose therein, and recovering the GDP-fucose therefrom; and a process for producing GKDM, comprising allowing a GTP precursor, a saccharide, a culture broth of a microorganism capable of forming GTP from a GTP precursor, and a culture broth of a microorganism capable forming GKDM from a saccharide and GTP to be present in an aqueous medium, forming and accumulating GKDM therein, and recovering the GKDM therefrom. | 2 |
CROSS REFERENCE TO RELATED APPLICATION
Pursuant to 35 U.S.C. §119, the benefit of priority from provisional application 61/340,031, with a filing date of Mar. 1, 2010, is claimed for this non-provisional application.
STATEMENT OF GOVERNMENT INTEREST
The invention described was made in the performance of official duties by one or more employees of the Department of the Navy, and thus, the invention herein may be manufactured, used or licensed by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.
BACKGROUND
The invention relates generally to vertical missile launchers. In particular, the invention relates to road-mobile launchers for surface-to-air intercept missiles.
Vertical missile launchers have conventionally been deployed aboard warships, such as cruisers and destroyers to replace rail launchers. Originally developed for anti-submarine warfare (e.g., ASROC, RUM-139), vertical launchers were subsequently deployed for other missiles for guidance using shipboard radar, such as Aegis. Missiles to be incorporated in ship-board vertical launcher arrays include Tomahawk (BGM-109) and Standard Missile. Of the latter, the SM-2 (RIM-67) and SM-3 (RIM-161) versions are used for surface-to-air interception of either hostile aircraft or ballistic warheads.
Conventional tactical surface-to-air missiles for are deployable on exposed ground-based launch stands. However, these involve deployment of several platforms for target detection, tracking, guidance and control.
SUMMARY
Conventional vertical missile launchers yield disadvantages addressed by various exemplary embodiments of the present invention. In particular, these designs provide such a launcher intended for relocatable ground transport.
Various exemplary embodiments provide a mobile terrestrial vertical missile launch system for relocatable ballistic missile deployment. The system is connectable to a transport truck and includes a trailer, a pivotable canister, a plurality of stabilizing legs, and an equipment module. The trailer has a hitch for connecting to the truck, a base for supporting wheels for road travel, and a flatbed platform having a transverse hinge.
In various embodiments the canister contains a launcher for at least one missile and is configurable by rotation at the hinge for disposal in either a longitudinal position for stowage or an erected position for deployment. The stabilizing legs are disposed along a periphery of the trailer. The legs can be disposed in one of an elevated position for stowage and a retarded position for ground engagement. The equipment container supplies electrical power, conditioning, communication and control for the missile.
BRIEF DESCRIPTION OF THE DRAWINGS
These and various other features and aspects of various exemplary embodiments will be readily understood with reference to the following detailed description taken in conjunction with the accompanying drawings, in which like or similar numbers are used throughout, and in which:
FIG. 1 is an assembly perspective view of a terrestrial-based vertical launcher;
FIG. 2 is an assembly perspective view of the vertical launcher;
FIG. 3 is an assembly elevation view of the vertical launcher;
FIG. 4 is an assembly elevation view of the vertical launcher; and
FIG. 5 is an exploded perspective view of the vertical launcher.
DETAILED DESCRIPTION
In the following detailed description of exemplary embodiments of the invention, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration specific exemplary embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. Other embodiments may be utilized, and logical, mechanical, and other changes may be made without departing from the spirit or scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims.
Various exemplary embodiments provide a system for deploying a modular vertically launched missile launcher previously used exclusively in ship-board installations on a fully mobile land-based platform resulting in an expeditionary type missile launching system. The design incorporates a modular vertical missile launcher from which to house and launch the missiles, a trailer capable of transporting the launcher and all of its associated sub-systems such that the launcher and its sub-systems are an erected and enabled on the trailer and can then be quickly stowed and transported without removal from said trailer.
The Mk 41 Vertical Launching System (VLS) has been successfully used on numerous United States Navy and allied ships for many years. Policy considerations for implementing tactical ballistic missile defense have led to interest in extending the field of operations of this missile launching system to ground-based applications. One inherent characteristic for more effective security and cost-effective logistics involves having the missile launching system be readily mobile. While many mobile missile launching systems have been developed in the past, this is the first known application of incorporating an in-service Navy missile launcher onto a fully road-mobile, or expeditionary, land-based platform.
FIG. 1 shows an assembly perspective view 100 of a launch system in the stowed configuration, appropriate for road-mobile towing. The launch system 100 includes a low flat-bed trailer 110 terminating at the longitudinal ends in a fore hitch 120 and an aft axle base 130 that support the wheels 140 . A canister 150 lies horizontally disposed on the trailer 110 substantially parallel to the trailer's longitudinal axis. The canister 150 contains a launcher for at least one missile stored therein, such as an SM-3 for ballistic defense, in an armored or hardened case for protection against weather and other potentially debilitating threats. The canister 150 can correspond to the Mk 41 VLS or similarly configured system.
A plurality of stabilizing legs 160 terminating in ground-pads are disposed along the longitudinal periphery of the trailer 110 , raised to extend upward substantially parallel to the sides of the canister 150 in the stowed configuration. Equipment modules 170 for supplying electrical power and HVAC support, radar tracking and missile control systems 180 , may be disposed on the base 130 . A transverse hinge 190 disposed on the trailer 110 (perpendicular to the trailer's longitudinal axis) attaches to one edge of the canister 150 for pivoting. The trailer 110 enables the canister 150 and accompanying equipment to connect to a large motorized truck for travel across road for deployment that can be relocated at short notice.
FIG. 2 shows a perspective view 200 of the launch system in the deployed configuration, appropriate for operational defense and target engagement. The canister 250 lies vertically disposed on the trailer 110 , having been rotated on the hinge 190 upward and rearward for ballistic launch of the missile. The stabilizing legs 260 can be retarded or folded down to inhibit rocking of the trailer as weight shifts during deployment and missile launch. The legs 260 can be rotated from their stowed position at their junction to the trailer 110 .
FIG. 3 shows an elevation view 300 of the launch system in the stowed configuration as shown from the port side. The canister 150 in the horizontal position occupies a flatbed fore portion 310 of the trailer 110 , adjacent to the hitch 120 . The mass of the canister 150 with the installed missile shifts the trailer's center-of-mass forward for improved road handling. A flatbed aft portion 320 of the trailer 110 can remain unoccupied during stowage. The stabilizing legs 160 are depicted as elevated for stowage. The upper edge of the canister 150 between the fore and aft portions 310 and 320 represents a deployed bottom free edge 330 .
FIG. 4 shows an elevation view 400 of the launch system in the deployed configuration. The canister 250 in the vertical position has been rotated by arrow 410 (clockwise 90° from the port side) along the hinge 190 . The legs 260 are deployed as being lowered for ground engagement. The wheels 140 at the base 130 can be elevated off the surface, depending on topographical conditions. The upper edge of the canister 250 between the fore and aft portions 310 and 320 represents a stowed bottom free edge 420 .
A fore ledge on the hitch 120 can support one bottom free edge 420 of the canister 150 in the stowed configuration. An aft ledge on the base 130 can support the other bottom free edge 330 of the canister 250 in the deployed configuration. A motor within the equipment 170 can be used to rotate the canister from supine stowage as position 150 to erect deployment as position 250 and/or the legs from upright 160 to retard as deployed 260 .
FIG. 5 shows an exploded perspective view 500 of the launch system for deployment. The trailer 110 includes the hitch 120 , the flatbed with the fore and aft portions 310 and 320 divided by the hinge 190 , and the base 130 containing the wheels 140 . Adjacently separated from the trailer 110 for installation are the legs 260 and the canister 250 for deployment, along with the equipment 170 and radar system 180 .
Various exemplary embodiments provide an expeditionary platform that can carry the Navy VLS in a stowed configuration along with all of its immediate sub-systems on a single towable unit or trailer for transport to a road-accessible launch site. Upon reaching the intended location, various exemplary embodiments provide erection and preparation for operations in a short period of time. Accomplishing this necessitates carrying all immediately necessary sub-systems on the same trailer or towable package as the launcher itself.
Various exemplary embodiments employ the existing Mk 41 VLS along with several other systems including: environmental conditioning (e.g., heating, ventilation, and air conditioning (HVAC), electrical power generation, fuel storage, pressurized water storage, electrical connection boxes, stabilizing jacks, armor plating, and mechanical erection devices to encompass a complete expeditionary VLS package.
The Mk 41 VLS has been in operation for many years and constitutes a modular, multi-purpose vertically oriented missile launcher capable of launching many Navy missiles installed aboard warships. Its conventional design inherently focuses around shipboard installation. The launcher has built-in electronics to operate and launch the missiles (albeit operating with ship-board power supply), a built-in gas management system to channel and direct missile exhaust away from the ship, and sufficient structure to store the missiles prior to launch.
However, because the Mk 41 VLS is designed to be installed in a warship, its design relies on numerous ship services including: electrical power, heating ventilation and air-conditioning (HVAC), and ballistic protection. Thus various exemplary embodiments have been developed to render the Mk 41 VLS independent of ship-board services by converting the launcher into a self-sufficient operating unit. For these embodiments, a separate command and control function can be assumed to remain external to the Mk 41 VLS mobile unit and communicate missile operational commands to the VLS module through an external data-communications interface.
Various exemplary embodiments are based on a custom-designed low-slung trailer arrangement where the primary long-bed of the trailer is positioned below the tops of the tires allowing for maximum overhead clearance. The Mk 41 VLS can be initially stowed in a horizontal configuration towards one end of the trailer. The Mk 41 VLS remains enclosed in an armored case that provides ballistic protection, anti-intrusion protection, and general protection from the environment. This armored case contains numerous access panels and doorways to enable personnel to install missiles, maintain equipment, and perform routine VLS related tasks.
Also integral to the armored skin is all of the necessary HVAC ducting to maintain internal temperature, humidity, and air quality for the system. All electrical, data, and communications connections can be conducted through one or more interface panels on the exterior of the armored case so that no access panels or doors remain open for an extended time during normal operation. The HVAC system, power generation unit, fuel storage units for the power generation unit, and fire suppression systems can be located at the two end of the trailer unit, either over the rear wheels or in the vicinity of the tongue or both.
For the trailer having been towed into desired position, integral support jacks can be deployed to stabilize the system to prevent vibration, tipping, or to correct for variations in site elevation. The Mk 41 VLS is then erected by pivoting it about a hinge pin located along the lower edge of the launcher connected to the trailer such that the launcher is rotated from a horizontal stowed configuration to a vertical deployed configuration. Erection of the launcher can either be accomplished through the use of an external crane system or preferably through a mechanical self-erection mechanism installed between the trailer and the launcher.
Once the launcher is fully erected it will need to be secured or latched to the trailer in the deployed configuration. HVAC, fire suppression, and power generation connections can either be made once the launcher is erected or some systems could be designed with sufficient flexibility in their connections to remain connected in both the stowed and deployed configuration. For services connected after erecting the launcher, all connections should preferably use ruggedized, flexible, quick-connect fittings and connectors to ensure a rapid set-up time. These aspects represent design considerations within the scope of the artisan of ordinary skill without departing from the scope of the invention.
The primary advantage to this system is the ability to take a previously ship-based missile launching system and incorporate it into highly mobile, rapid deployment land-based missile launching system. The inventive features of these exemplary embodiments include the incorporation of a ship-based system reliant on shipboard services into a self-contained land-based system.
While certain features of the embodiments of the invention have been illustrated as described herein, many modifications, substitutions, changes and equivalents will now occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the embodiments. | A mobile terrestrial vertical missile launch system is provided for relocatable ballistic missile deployment. The system is connectable to a transport truck and includes a trailer, a pivotable canister, a plurality of stabilizing legs, and an equipment module. The trailer has a hitch for connecting to the truck, a base for supporting wheels for road travel, and a flatbed platform having a transverse hinge. The canister contains launcher for at least one missile and is configurable by rotation at the hinge for disposal in either a longitudinal position for stowage or an erected position for deployment. The stabilizing legs are disposed along a periphery of the trailer. The legs can be disposed in one of an elevated position for stowage and a retarded position for ground engagement. The equipment container supplies electrical power, environmental conditioning, tracking, communication and control for the missile. | 5 |
BACKGROUND OF THE INVENTION
The present invention relates to electric current sources based on fuel elements.
Hydrogen is a “clean fuel” because it can be reacted with oxygen in hydrogen-consuming devices, such as a fuel cell or combustion engine, to produce energy and water. Virtually no other reaction byproducts are produced in the exhaust. As a result, the use of hydrogen as a fuel effectively solves many environmental problems associated with the use of petroleum based fuels. Safe and efficient storage of hydrogen gas is, therefore, essential for many applications that can use hydrogen. In particular, minimizing volume, weight and complexity of the hydrogen storage systems are important factors in mobile applications.
The development of fuel cells as replacements for batteries in portable electronic devices, including many popular consumer electronics such as personal data assistants, cellular phones and laptop computers is dependent on finding a convenient and safe hydrogen source. The technology to create small-scale systems for hydrogen supply, storage and delivery has not yet matched the advancements in miniaturization achieved with fuel cells.
A hydrogen fuel cell for portable applications needs to be compact and lightweight, have a high gravimetric hydrogen storage density, and be operable in any orientation. Additionally, it should be easy to match the control of the system's hydrogen flow rate and pressure to the operating demands of the fuel cell.
The existing hydrogen storage options, which include compressed and liquid hydrogen, hydrided metal alloys, and carbon nanotubes, have characteristics which complicate their use in small consumer applications. For instance, compressed hydrogen and liquid hydrogen require heavy tanks and regulators for storage and delivery, metal hydrides require added heat to release their stored hydrogen, and carbon nanotubes must be kept pressurized.
Alternatives for hydrogen storage and generation include the class of compounds known as chemical hydrides, such as the alkali metal hydrides, the alkali metal aluminum hydrides and the alkali metal borohydride. The hydrolysis reactions of many complex metal hydrides, including sodium borohydride, (NaBH4) have been commonly used for the generation of hydrogen gas.
In those applications where a steady and constant supply of hydrogen is required, it is possible to construct hydrogen generation apparatus that control the contact of a catalyst with the hydride fuel. Such generators typically use a two-tank system, one for fuel and the other for discharged product. The hydrogen generation reaction occurs in a third chamber that contains a metal catalyst and connects the two tanks. However, such two-tank designs are not typically directionally independent or amenable to miniaturization.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a device for and method of storage and generation of hydrogen for autonomous current sources based on fuel cells, which constitutes a further improvement of the existing solutions.
In keeping with these objects and with others which will become apparent hereinafter, one feature of the present invention resides, briefly stated, in a device for producing hydrogen for power sources, comprising a housing; means for containing electrolyte in said housing; means for containing aluminum in said housing; means for periodically bringing the aluminum and the electrolyte in contact for production of hydrogen; and means for the withdrawing the hydrogen to a power source.
In accordance with the present invention, another feature of the present invention resides, briefly stated, in a method further comprising setting a predetermined pressure in said container so that when an interior of said housing is connected with a power source, a pressure which is lower than the said pressure is provided inside said container and the aluminum is brought in contact with the electrolyte, while after generation of hydrogen and withdrawal from said container when a pressure becomes again equal to the said pressure the aluminum and electrolyte are disengaged from one another and generation of hydrogen is stopped until a next cycle.
In the present invention the hydrogen production is performed by aluminum assisted water split in accordance with the following formula:
2Al+6H2O[ in alkaline solution ]→2Al(OH) 3 +3H 2 ↑
As a result of reaction of aluminum with water in alkaline medium, a pure hydrated aluminum oxide is produced (AlOH 3 .nH 2 O) and hydrogen. The yield of hydrogen can be substantially 3.7%. Taking into consideration that a quantity of water required for reaction can be provided in half by a returned water generated in the electrochemical power system based on the fuel cell during the use of an energy device, the yield of hydrogen can reach 7-10%. The necessary condition of the reaction is a direct contact of all reactant (aqueous alkaline solution and aluminum) with each other. The quantity of produced hydrogen can be regulated by a magnitude of area of contact of the surfaces of particles of aluminum which interact with water.
The aluminum can be used in any form, such as foil, sheet, wire, granules (pellets) of regular and irregular shape. It is important to provide an optimal area of surface of reaction and its completeness. It is important that one of the linear sizes of the used form of aluminum parts is small and does not exceed 0.1-1 mm.
The important feature of the present invention is also the content of the electrolyte, in particular NaOH with addition of LiOH, NaInO 2 and Na 4 Ga 2 O 3 *nH2O.
The required quantities include 4 M of NaOH with 1-10 Wt % of the above mentioned additives.
The novel features of which are considered as characteristic for the present invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view schematically showing a device for a hydrogen gas generation in accordance with the first embodiment of the present invention;
FIG. 2 is a view schematically showing a device for a hydrogen gas generation in accordance with the second embodiment of the present invention;
FIG. 3 is a view schematically showing a device for a hydrogen gas generation in accordance with the third embodiment of the present invention;
FIG. 4 is a view showing a graph of hydrogen generation rate versus time for a hydrogen production by aluminum assisted water split according to the present invention;
FIG. 5 is a view showing a graph of a total amount of hydrogen produced versus time for hydrogen production by aluminum assisted water split according to the present invention;
FIG. 6 is a view showing a graph of a hydrogen output pressure versus time for a hydrogen production by aluminum assisted water split according to the present invention; and
FIG. 7 is a view showing a graph of a hydrogen generation temperature versus time for hydrogen production by aluminum assisted water split according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A device for hydrogen gas generation in accordance with one embodiment of the present invention is shown in FIG. 1 . The device has a housing 10 , a unit for setting a controlling pressure 12 , a sealing unit 14 for sealing introduction of gas which sets the pressure, a unit 16 for sealing a pipe for supply of a generated hydrogen to a fuel cell, a unit 18 for sealing a removable lid of the device. The device further has a flexible bay 20 formed as an electrolyte container for accommodating electrolyte 22 . The device further has a container 30 with a portion of aluminum, and a unit 24 for sealing the container with aluminum.
Reference numeral 26 identifies a unit of sealing a pipe for return of water from the fuel cell. The device further has unit 32 for filtration and withdrawal of generated hydrogen from the device, a flexible pipe 34 for withdrawal of the generated hydrogen from the flexible back 32 , a pipe 40 for supplying the generated hydrogen to a fuel cell, and a pipe 50 for return of water from the fuel cell into the device.
The housing 10 can be composed of rigid material, for example from a thermoplastic material such as polyamide, ABC, and thermoreactive plastic material such as fluoroplastics or silicon elastomers. The container 20 for electrolyte is composed of an elastic material, for example from rubber EPDM or silicon rubber, and accommodates a required quantity of electrolyte needed for the chemical reaction. The container 30 with a portion of aluminum, the sealing unit 24 , and the unit for filtration and removal of generated hydrogen is located inside the container 20 .
The unit 32 for filtration and removal of the generated of the united hydrogen is connected through the sealing unit 16 by the flexible pipe 34 with a pipe for supply of hydrogen 40 to the fuel cell. The device for setting controlling pressure 12 is connected through the sealing unit 14 to the housing 10 , and the pipe for return of water from the fuel cell 50 is connected to the housing 10 through the sealing unit 26 . The housing 10 is composed of two parts connected with one another by the sealing unit 18 .
In the initial position the device formed as a cartridge does not have active components. In order to supply the components into the cartridge, it is necessary to open the housing 10 in the sealing unit 18 which can be formed as screw connection, a bayonet connection or another fast connection, to disconnect the sealing unit 24 , to pour aqueous solution, for example of 4 M Na OH with additives 1-10 Wt % LiOH, NaInO 2 and Na 4 Ga 2 O 3 *nH2O into the electrolyte container 20 , to place the container 30 with a portion of aluminum inside the container 20 , to seal the sealing unit 24 , to seal the housing 10 .
For activation of the device, it is necessary to connect the pipe for supply of hydrogen 40 to the fuel cell, and the pipe for return of water 50 to a corresponding part of the fuel cell.
After the connection of the pipe 40 , insufficient pressure, relative to pressure set by the unit 12 is provided. This leads to squeezing of the electrolyte container 20 which is composed of elastic material, and the electrolyte 22 is brought into contact with the aluminum in the container 30 , so that in accordance with the above mentioned reaction, generation of hydrogen starts. This process continues until the pressure inside the container 20 becomes equal to the pressure set by the setting unit 12 . After the pressures inside the elements 12 and 20 become equal, electrolyte and aluminum are disconnected, and reaction of generation of hydrogen automatically stops until a next cycle. The next cycle starts when the pressure of hydrogen in the fuel cell again becomes smaller than the pressure set by the unit 12 , and the process continues until a complete use of the reactants. As can be seen, the device formed as a cartridge can operate in any spatial orientation.
After the complete use of the reactants, the device is disconnected from the fuel cell and is recharged. For this purpose the housing 10 is open in the sealing unit 18 , the sealing unit 24 is disconnected, the container 30 is removed from the container 20 , the spent solution of electrolyte is removed from the container 20 , and the container is washed, while the spent solution can be sent for recycling, a fresh solution specified herein above is introduced into the electrolyte container 20 , the container 30 with a portion of aluminum is introduced into the container 20 , the sealing unit 20 is sealed, the housing 20 is sealed, and the device is ready for next use.
FIG. 2 shows another embodiment of the device in accordance with the present invention. The device has a housing 10 , a unit 12 for setting controlling pressure, a unit 14 for sealing introduction of gas that sets by pressure, a unit 16 for sealing a pipe for supply of generated hydrogen into a fuel cell, a unit 18 for sealing a removable lid of the device. Reference numeral 22 identifies electrolyte. The device further has a container 30 with a portion of aluminum, a unit 24 for sealing the aluminum container, a unit 26 for sealing a pipe for return of water from a fuel cell, a flexible pipe 34 for removal of generated hydrogen from the flexible bag.
The device further has a pipe 40 for supplying generated hydrogen to the fuel cell, a pipe 50 for return of water from the fuel cell into the device. The device further has an internal bag 60 composed of a porous hydrophobic membrane which allows a passage of hydrogen a net 62 which can be formed as a plastic net and reinforced for providing a required gap between the internal bag 60 and a flexible bag 64 . The flexible bag 64 is impermeable for hydrogen and electrolyte. Reference numeral 66 identifies a unit for withdrawal of hydrogen from the device.
In the device shown in FIG. 2 the housing 10 is also composed of rigid material as in the embodiment of FIG. 1 . The container formed as a bag for electrolyte 64 is located inside the housing and composed of an elastic material such as EPDM rubber or silicon rubber with a supply of the electrolyte 22 , and the container with a portion of aluminum 30 . The internal bag 60 is composed of a gas permeable membrane known in the art and more permeable to hydrogen than water, such as silicon rubber, fluoropolymer, or any common hydrogen-permeable metal membrane, such as palladium-gold alloy membrane. Another bag 62 composed of a plastic mesh or net, for example of polyethylene or polypropylene fluoroplastic and another material which is resistant in alkali solutions, is provided between the elements 60 and 64 for obtaining a gap therebetween. The container 30 with a portion of aluminum and electrolyte 22 are introduced into the container 64 through the hermetically sealed window 24 . The unit for withdrawal of hydrogen 66 is arranged on the container 64 and connected by the flexible pipe 34 , which through the sealing unit 16 is connected with the pipe 40 for supply of hydrogen to the fuel cell. The unit 12 for setting controlling pressure and the pipe for return of water from the cell 50 are connected through the sealing unit 14 and the sealing unit 26 correspondingly to the housing 10 . The housing 10 is composed of two parts connected with one another by the sealing unit 18 .
As in the previous embodiment, in the initial position there are no reactants in the device. It is then necessary to open the housing 10 in the area of the sealing unit 18 , to disconnect the sealing unit 24 , to introduce the electrolyte into the container 20 , to place the container 30 with a portion of aluminum into the container 60 - 64 , to seal the unit 24 and the housing 10 .
In order to activate the device it is necessary to connect the device 40 for supply of hydrogen to the fuel cell and the pipe of 50 for return of water to the corresponding parts of the fuel cell. After the connection of the pipe 40 an insufficient pressure relative to the pressure set by the unit 12 is provided. This leads to squeezing of the composite container for electrolyte 60 - 64 , which is composed of the elastic material, the electrolyte 22 is brought in contact with aluminum in the container 30 , and hydrogen is generated in accordance with the above mentioned reaction. After equalization of the pressure inside the elements 20 and 64 , the electrolyte and aluminum are disengaged from one another and the reaction of generation of hydrogen automatically stops until the next cycle. The next cycle starts when pressure of hydrogen in the fuel cell again becomes lower than the pressure set by the unit 12 , and the process continues till full use of reactants.
After the complete use of reactants the device is disconnected from the fuel cell and is recharged. For this purpose the housing 10 is open in the area of the sealing unit 18 , the sealing unit 24 is disconnected, the container 30 is removed from the composite container 60 - 64 , the electrolyte is removed from the container 20 and washed, and the spent solution is sent for recycling, a fresh solution of the electrolyte is introduced into the composite container 60 - 64 , the container 30 with the portion of aluminum is introduced into the composite container 60 - 64 , the unit 24 is sealed, and the housing 10 is sealed.
FIG. 3 shows another embodiment of the present invention. The device for hydrogen generation has a housing 10 , a unit 12 for setting controlling pressure, a unit 14 for sealing introduction of gas which sets the pressure, a unit 16 for sealing a pipe for supply of generated hydrogen to a fuel cell, a unit 18 for sealing a removable lid of the device. Reference numeral 22 identifies electrolyte. The device further has a unit 76 for sealing the container with aluminum, a unit 26 for sealing a pipe for return of water from the fuel cell, a container 30 with a portion of aluminum, a pipe 40 for supply of generated hydrogen to the fuel cell, a pipe 50 for return of water from the fuel cell, a unit 70 for removal of hydrogen from the device, a cylinder 72 providing a displacement of aluminum container by means of a piston rod 78 under the action of the gas from the unit 12 , a piston 74 , and a unit for sealing the piston rod 78 . The device further has a flexible bag 80 which is impermeable for hydrogen and electrolyte.
As before, the housing 10 is composed of a solid material, for example a plastic material. The container or bag for electrolyte 80 composed of an elastic material, for example of EPDM rubber or silicon rubber or plastic with the electrolyte 22 is located in the housing. The housing 10 is composed of two parts removably connectable by the sealing unit 18 . The electrolyte container 80 is connected to the housing 10 in the area of the sealing unit 18 . The unit for filtration and removal of hydrogen 70 with the pipe 40 for supply of hydrogen to the fuel cell and the device for regulating the position of the container 30 with aluminum relative to the level of the electrolyte 20 are located in an upper part of the housing 10 . This regulating device includes the unit 12 for setting a controlled pressure, the cylinder 72 with the piston 74 , the piston rod 78 and the sealing unit 76 , the pipe 50 for water return from the fuel cell through this sealing unit 26 . The pipe 50 for return of water from the fuel cell is connected to the housing 10 through the sealing unit 26 .
As in the previous embodiments for introducing reactants it is necessary to open the housing 10 , to introduce the electrolyte into the container 80 , to connect the container 30 with aluminum to the piston rod 78 at a corresponding height, to seal the housing 10 .
For activation of the device it is necessary to connect the pipe 40 for hydrogen to the fuel cell and the pipe 50 for water return to the corresponding part of the fuel cell. Immediately after the connection of the pipe 40 an insufficient pressure relative to the pressure set by the unit 20 is produced. This leads to lowering of the container 30 with aluminum till its contact with the electrolyte 22 , and they are brought in contact with one another, whereafter in accordance with the above mentioned reaction generation of hydrogen starts. The process will continue till the pressure inside the housing 10 equalizes with the pressure set by the unit 12 . After the equalization of the pressures the container 30 with aluminum connected to the piston rod 78 moves upwardly, the electrolyte and aluminum are disengaged with one another, and the reaction stops until a next cycle. The next cycle starts when the pressure of hydrogen in the fuel cell transmitted into the housing 10 is again less than the pressure set by the element 12 , and the process continues until complete use of the reagents. The device can work in a substantial vertical position +/−30°. After the use of the reactants the device is disconnected from the fuel cell and is recharged/replaced correspondingly.
It should be mentioned that the container 30 for aluminum is configured so as to provide a contact of the electrolyte with the aluminum in the container. The container 7 can be formed as a mesh, net, etc, which allows the above mentioned contact. The important feature of the present invention is that the aluminum is provided in form of small particles with a thickness substantially not exceeding 0.1-1 mm. This provides a high degree of contact between the aluminum and the electrolyte and high efficiency of the process.
The inventive device and method have been tested. An example is presented herein below just for illustration purposes and is not to be constructed as limitation of the present invention, since many deviations are possible without a parting of the spirit and scope of the invention.
The device shown in FIG. 3 is utilized here as an example. It was constructed to bench test of the invention. 300 ml of 4 M of solution NaOH with corresponding additives was introduced into the flexible bag 80 . 65 gram of industrial aluminum alloy 6061 was introduced into the container 30 as a band with a thickness of 1 mm, wound into a spiral with an outer diameter approximately 75 mm. The test was made for obtaining hydrogen in the quantity of approximately 180 liter with a flow rate approximately 0.65 liter per minute during approximately 5 hours. The results of this experiment are shown in FIGS. 4 , 5 , 6 and 7 . 207,089 liter of hydrogen was produced with efficiency of 0.677 liter per minute during 5 hours. During the test a low pressure set by the self regulating system has observed inside the device as shown in FIG. 6 and a corresponding calculated value of temperatures as shown in FIG. 7 . It clearly shows that the device and method can be used as a hydrogen source for portable fuel cell power systems and also for industrial/residential power systems and electric vehicle operations.
It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions and methods differing from the type described above.
While the invention has been illustrated and described as embodied in a device for and method of storage and generation of hydrogen for autonomous current sources based on fuel cells, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention. | A device for generating hydrogen for power system based on hydrolysis aluminum assisted water split has a housing, a unit for containing aluminum in the housing, a unit for periodically bringing the aluminum and the electrolyte in contact for production of hydrogen, and a unit for the withdrawing the hydrogen to a power source. | 2 |
BACKGROUND AND SUMMARY OF THE INVENTION
This invention relates to the field of compressors. The traditional compressor operates with an up and down reciprocating stroke, and its power consumption and abrasion characteristics are very high. Although an improved gyro-compressor which can minimize its power consumption and abrasion has been designed, it can neither absorb the input compressed air to extremity nor transmit the input compressed air by the compressor piping in large amounts freely and systematically. How to overcome (remedy) these deficiencies are the objects of the present invention.
It is thus an object of the present invention to provide the dual functions of an exhaust fan and a compressor in one unit which can operate with a minimum power. In other words, it is characterized by its large proportional amount of exhausted compressed air with respect to the amount of input compressed air. It is another object of the present invention to provide a device to take, through the piping's exhausting and absorbing function, the place of the factory stack and treat the exhausted smoke and gas, etc., in piping based on their quality and composition chemically and physically and then filter, deheat and dehumidify them in order to let them turn into colorless, odorless and poison free clear air, and additionally the air convection current and function combustion promotion in furnace through the speed control device.
It is a still further object of the present invention to provide a innovated central air condition center unit, the exhaust stroke of which is fixed to piping and disposed concentratedly in the wall in such a way as to increase the internal space of a building room. Therefore, the present invention can be designed in construction together with the waterpipe, wire pipe and gas pipe as a whole, cross-the-boardly. The present invention acts as a multi-purpose compressor; the small size compressor comprising four sets of absorbing-exhausting strokes. The first set is connected to a room and used as the air conditioned to condition the air by means of supplying the cold or warm air into the room through filtering, de-heating or heating the air. The second set is connected to the place where the smoke exhaust is fixed as the exhauster to exhaust the smoke or oil through a filtering net. The third set is connected to a water closet and is used as the device to exhaust therefrom the odor and absorb thereto the fresh air. The fourth set is connected to dining room or bedroom to act as the electric fan. The large size compressor can freely be divided into 8, 9, 10, . . . set to be used as the central air conditioning unit for the great building or factory. The most important advantage of the present invention is to save the energy in addition to its lower production cost. Therefore, the present invention is a popular air conditioning device. It is further object of the present invention to provide by adapting, a liquid compressing pump to treat and purify, with the chemical or physical processes, the polluted waste water for the chemical factory, to serve the purpose of purifying the waste water.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 shows an exploded perspective view of a compressor constructed in accordance with and embodying the present invention.
FIG. 2 shows a perspective view, partially broken away, of a compressor constructed in accordance with and embodying the present invention.
FIG. 3 is a plan view of the cam on the upper part fixed seal plate and its "S" shape socket at its bottom.
FIG. 4 is a side view illustrated in FIG. 3.
FIG. 5 is a plan view of the "S" socket enclaved on the pulley at the top of slider.
FIG. 6 is a plan view of the present compressor cylinder showing "S" wing shaft to the inleting stroke of the air chamber.
FIG. 7 shows a side view of a slider device used in the compressor of the present invention.
DETAILED DESCRIPTION
Referring now by reference numerals to the FIG. 1, this invention is the multi-purpose synchronous three-angle-cross compressor comprising two sets of upper and lower, symmetrical, fixed seal (end) plates 8 enclaved into star disc cam 9 respectively, a sealed cylinder in the unit, equipped in it with a "S" wing shaft 7, some equiangular convex plate 2 fixed around the sealed cylinder, a slider 4 fixed at the socket 3 channelling the section of convex plate 2, cylinder and its internal wall, the pulley 15 fixed on slider, some inlets 12 and outlets 13 on the wall of sealed cylinder 1 to function as the inleting and outleting devices which are the main components of the present invention.
Referring to FIG. 3 and FIG. 4, the present invention is a compressor comprising a cover 16 completed by a cut internal circle 9' on the upper part of fixed and sealed plate 8, enclaved on star disc cam 9, a central shaft 5 at the center of the sealed plate 8, going through the whole compressor, a bearing 11 comprising the steel balls 20 and lubricant oil, fixed at the center of sealed plate 8 to make the shaft 5 operate smoothly, a convex disc 6 fixed below the bearing (a disc socket 6 in the section of bottom of sealed plate 8), which acts as a device to fix the "S" wing shaft 7 in sealed cylinder 1 with shaft rotation, prevent the air leakage from the clearance between the star disc cam 9 at the upper and lower and central position, a "S" socket 10 in the section of bottom of star disc cam 9, which can be enclaved on pulley 15 at the upper ends of slide 4 in the cylinder 1 the bottom track of which, when star disc cam 9 with shaft center rotates, will start the pulley 15, and make the slider 4 reciprocate (refer to FIG. 5) and a bolt 14 screwed which when star disc cam 9 is set in shaft 5, prevents the star cam 9 from dropping.
Referring to FIG. 1 and FIG. 6, the present invention comprises a sealed cylinder 1 which is hollow inside, the perimeter of which is fixed some equiangular convex pillar plate 2 (the small size compressor with 4 sets convex pillar plate, the large size compressor with 8, 9, and 10 . . . sets convex pillar plate). The slider 4 is fixed in the socket 3, channeling the internal section of convex pillar plate 2 and internal wall of cylinder 1. The slider 4 is provided with an arm extension 17 on its upper and lower parts and some pulleys 21 are provided with between the arm extension 17 and slider 4 in order to let it slide on sealed fixing plate 8. Further, the internal upper and lower end of the slider 4 is provided with a pillar 17' being secured to upper and lower pulleys 15, respectively. The pulley 15 is secured to the track 10 of "S" socket fixed at the bottom of the star disc cam 9 on the upper cover. Moreover, the external shell of sealed cylinder is provided with the inlet 12 and outlet 13. The inlet stroke is constructed with the free valve and except the moment the air sideswipes the point of "S" wing shaft in cylinder 1, the air can be inleted into the compressing chamber 19. The outlet stroke is constructed with the reverse valve and the air compressed into the compressing chamber 19 is outleted from outlet 13 with reverse valve under excluding by "S" wing shaft 7, and the retardation of the slider attached closely to "S" wing shaft. When the point of the "S" wing shaft 7 sends the slider 4 to socket 3 of the convex pillar plate 2, entirely the whole strock of the compressing chamber is completed and the air is completely exhausted from reverse valve 13. For the second compressing chamber, it is the beginner to exhaust continuously the inleted air from the separate set outlets beside the slider.
Referring to FIG. 1 and FIG. 2, the present invention is a compressor operated by motor starts the middle shaft 5 to make the "S" wing shaft 7 in the sealed cylinder 1 rotate and exclude the air inleted from the inlet 12 with free valve to the outlet 13 with reverse valve. (The compressing chamber exhausts the air from the outlet 13 by means of the rotation of "S" wing shaft 7 and gradual reduction of space by slider 4 sliding along "S" shaft 7.) The compressor is characterized by its two similar and symmetrical upper and lower sealed plates 8 comprising the enlaved star disc cam 9 and two sets of upper and lower "S" sockets 10. The slider 4 of the present invention compressor works under the track function of "S" socket 10 at the bottom of upper and lower star cams 9, which starts the pulley to reciprocate along socket 10. The present inventive compressor comprises three "S" components; the "S" wing shaft 7 and two "S" socket tracks 10 at the bottoms of upper and lower star disc. The present inventive compressor is characterized by its low-noise and saving of energy in 60%. The principle of saving energy of the present invention includes: (1) The sliding of slider 4 and pulley 15 of the present invention is characterized by its high speed and simple operation in comparison with the traditional gro-compressor. (2) The "S" wing shaft in cylinder functions as two compressing valves and make "S" wing shaft operation simple under the principle of couple. (3) The present inventive compressor provides the exhausting pressure with lesser energy by taking advantage of the fact that the inlet avails itself of more absorbing power than that of the outlet. (The small size compressor comprises four compressing chambers with three inlets and two outlets each, totalling 12 inlets and 8 outlets). | An epoch-making new type compressor is characterized by its sealed cylinder, the upper part gyro-cam (in S shape) of which starts slider in the cylinder (it is provided with the same shaft and in the same "S" shape with the upper gyro-cam) for forth and back coordination and engage the synchronous three angle-cross operation whereby the slider goes forth and back along the socket in the cylinder. The air goes into the compressing chamber through the inlet with the free valve beside the slider and goes out through the outlet with the reverse valve beside the other slider (in the front position of the first slider) by means of excluding by the slider attached to the wing shaft in cylinder. | 5 |
BACKGROUND OF THE INVENTION
(1) Field of the Invention
The present invention relates to a device for positioning at a reaction plate, the device being configured to seat a reaction vessel at the reaction plate.
(2) Description of the Related Art
Laboratory based chemical reactions are typically carried out in a reaction vessel and where the reaction medium is liquid based, the reaction vessel is typically a round bottomed glass flask, commonly borosilicate, which is sold under the brand name Pyrex® by Corning of Corning, N.Y.
In order to drive the reaction heat is supplied to the reaction vessel which in turn transfers the heat to the reaction medium. The common bunsen burner represents one of the more primitive sources of heat used in the laboratory to heat reaction vessels. A further example is the commonly used oil bath in which the oil is heated by heating elements located within the bath. Oil baths have found particular use where elevated temperatures are required.
When used within a laboratory environment, the naked flame of the bunsen burner is particularly hazardous as it may serve as an ignition source for flammable solids, liquids or vapour. Oil baths pose a number of significant hazards. Firstly, the viscosity of the oil decreases when heated and spillage or splattering of the heated oil commonly results in skin burns or provides an ignition source. However, one of the more frequent accidents associated with oil baths stems from overheating of the oil resulting in ignition or explosion.
Hotplates and hotplate stirrers have been available for sometime and represent significantly safer laboratory heat sources. Hotplate stirrers operate by generating a rotating electromagnetic field in the region of the hotplate which induces a rotation effect on a magnetised stirring bar positioned within the liquid to be stirred. Resistance heating elements positioned in contact with the hotplate provide a means for heating the substantially planar working surface. Heat is supplied from the hotplate either directly to the reaction vessel, in contact with the hotplate, or via a liquid, typically an oil bath, positioned on the hotplate working surface. When used in combination with an oil bath, the significant risks posed to laboratory personnel remerge. Where a liquid/oil bath is not used the limited surface contact area between the planar hotplate and the curved flask provides for inefficient heat transfer and a limited heating effect.
One known device includes an adapter block constructed from aluminum or stainless steel for positioning over a stirrer hotplate. The adapter block comprises a plurality of recesses, each recess being configured to seat and partially house a reaction vessel. As a result of the extended surface contact area between the adapter block and reaction vessel, heat generated by the hotplate is efficiently transferred to the reaction medium within the reaction vessel.
The known device described above is specifically designed for parallel synthesis involving the simultaneous heating and stirring of multiple reaction vessels positioned outside the perimeter of the hotplate. This known adapter block is specifically designed for use with test tube or boiling tube type reaction vessels having a substantially elongate shape. Additionally, as the reaction vessels are located outside the perimeter of the reaction plate the rotational effect imparted to the magnetised stirring bar within each reaction vessel is reduced. This may be a particular problem where the reaction medium is particularly viscous.
BRIEF SUMMARY OF THE INVENTION
The inventors provide a reaction vessel support device configured for positioning at a reaction plate, the device being adaptable and configured to receive and support a single or a plurality of reaction vessels of different shapes and dimensions. The device of the present invention is modular, being constructed from separate and interchangeable components. In particular, a base unit capable of positioning at the reaction plate is configured to mate with an insert selected from a set of inserts, each respective insert being configured to seat a different shaped and/or sized reaction vessel.
The base unit may comprise a single recessed portion positioned within the base unit so as to be aligned directly over the reaction plate such that the majority of the recessed portion is located within the perimeter of the reaction plate. An insert selected from the range of different inserts is capable of seating within the recessed portion. Effective heat transfer is provided between insert and base unit due to the shape and dimensions of an exterior surface of the insert corresponding to the shape and dimensions of the recessed portion of the base unit. In particular, the distance between the insert and recessed portion, in the region of the recess, may be within the range 0 to 5 mm.
As the recess, the insert and hence the reaction vessel are aligned centrally with respect to the heating plate an enhanced heating effect is achieved over similar known devices in which the reaction vessels are positioned off centre. Additionally, effective stirring of the reaction medium is also possible, particularly where viscous liquids are used due to this centralised location of the reaction vessel within the magnetic field generated over the reaction plate.
According to a first aspect of the present invention there is provided a reaction vessel support device for positioning at a reaction plate, said device comprising: a base unit capable of positioning in contact with said reaction plate; an insert formed non-integrally with said base unit, said insert comprising at least one reaction vessel receiving portion capable of seating and locating about a portion of a reaction vessel; and a single recessed portion formed in said base unit capable of seating and locating about said insert, said recessed portion positioned at said base unit such that said insert is located substantially centrally relative to said reaction plate.
Preferably, the shape and dimensions of a convex surface region of said insert configured for locating within said recessed portion correspond substantially to the shape and dimensions of the concave recessed portion of the base unit.
Preferably, a shape of said insert and said recessed portion are configured such that a distance between said recessed portion and said insert, in the region of said recessed portion, is substantially uniform. The distance between the convex surface region of the insert and the surface of the recessed portion may be substantially zero or the insert and base unit may be configured to provide a gap distance of up to 5 mm.
Preferably, the recessed portion is dish or bowl shaped being defined by at least one side wall and a base.
Preferably, each insert comprises a single reaction vessel receiving portion capable of seating and locating about a portion of a single reaction vessel. Alternatively, each insert may comprise a plurality of reaction vessel receiving portions wherein each insert is capable of seating a plurality of reaction vessels.
Each insert and in particular the reaction vessel receiving portion may be designed to seat and locate about a reaction vessel of specific size and shape. Accordingly, via the inserts, the reaction plate adapter of the present invention may be configured to support independently round bottom flasks of sizes of 25 ml, 50 ml, 100 ml, 250 ml, 500 ml, 1 L, 2 L or 3 L. Additionally, the inserts may be configured to receive and support reaction flasks of any shape commonly used within the laboratory environment. The present invention is also configurable for use with sealable high pressure reaction vessels.
A lip may be provided at the insert configured for seating at an upper region of the recessed portion whereby the insert may be suspended within the recess by the lip. The lip may be annular or may be discontinuous possibly in the form of radially extending projections.
Preferably, the device comprises location means provided at said base unit capable of seating said base unit in position at the reaction plate. The location means is capable of inhibiting lateral displacement of the device relative to the stirrer hotplate.
A lower surface of the device may comprise a central cavity corresponding in size and shape to the reaction plate. Accordingly, the reaction plate is configured to locate partially within the cavity so as to ensure the device is effectively located in position. Alternatively, location feet or projections may be provided towards the underside of the base unit for abutting against the reaction plate and releasably locking the device in position. In particular, the location feet or projections may be removeably connected to the base unit, for example being screwed into the underside surface. Accordingly, a user may detach and reattach the location feet at the base unit enabling the device for use with reaction plates of different sizes and shapes. For example, a square reaction plate may require four location feet provided at the underside surface of the base unit whilst three location feet would be sufficient to secure the device in position at a substantially circular reaction plate.
Preferably, an underside surface of the base unit comprises means to enable the location feet to be secured at a plurality of different positions on the underside surface such that the location means is adaptable and may be configured specifically by a user to allow the device to be secured to any one of a plurality of different shaped and sized reaction plates.
The base unit and insert of the present invention may be made of any chemically resistant material including for example a polymer based compound, a metal, in particular aluminium or a metal alloy, in particular stainless steel. Additionally, the material of the present invention is chosen to provide efficient heat transfer from the reaction plate to the reaction vessel.
According to a second aspect of the present invention there is provided a device for positioning at a reaction plate configured to support at least one reaction vessel, said device comprising: a base unit capable of positioning in contact with said reaction plate; an insert formed non-integrally with said base unit, said insert comprising a dish-like configuration having a concave surface region and a convex surface region, wherein said concave region of said insert is capable of seating and locating about a portion of a reaction vessel; and a single recessed portion formed substantially centrally within said base unit capable of seating and locating about said convex portion of said insert.
Accordingly, due to the single recessed portion being formed substantially centrally within the base unit, the reaction vessel, when seated at the insert, may be positioned substantially centrally within the perimeter of the upper surface of the reaction plate.
According to a third aspect of the present invention there is provided an adapter block device for a stirrer hotplate, said device comprising: a base unit capable of seating on said reaction plate, said base unit comprising an internal bowl-like cavity, formed substantially centrally within said base unit, said cavity comprising side walls and a base; and a dish-like insert comprising at least one concave surface region capable of seating and locating about a portion of a reaction vessel, and a convex surface region configured to mate with said bowl-like cavity of said base unit, wherein said insert is capable of being removeably accommodated within said base unit.
The device of the present invention is capable of fitting to a magnetic stirrer, a hotplate or a magnetic stirrer hotplate of the kind typically used in a laboratory environment.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of the invention and to show how the same may be carried into effect, there will now be described by way of example only, specific embodiments, methods and processes according to the present invention with reference to the accompanying drawings in which:
FIG. 1 herein is a perspective view of a reaction vessel support device mounted on a magnetic stirrer hotplate according to a specific implementation of the present invention;
FIG. 2 herein is a cross sectional perspective view of the device and hotplate of FIG. 1 herein;
FIG. 3 herein is perspective view of the device of FIG. 1 herein;
FIG. 4 herein is a plan view of the device of FIG. 1 herein;
FIG. 5 herein is a cross sectional side elevation view of the device of FIG. 1 herein;
FIG. 6A is a perspective view of an insert capable of use with the device of FIG. 1 herein;
FIG. 6B herein is a cross sectional side elevation view of the insert of FIG. 6A herein;
FIG. 7A herein is a perspective view an insert capable of use with the device of FIG. 1 herein;
FIG. 7B herein is a cross sectional side elevation view of the insert of FIG. 7A herein;
FIG. 8A herein is a perspective view of an insert capable of use with the device of FIG. 1 herein;
FIG. 8B herein is a cross sectional side elevation view of the insert of FIG. 8A herein;
FIG. 9 herein is a graph of the heat transfer performance of the device of the present invention compared with a conventional oil bath;
FIG. 10 herein is a perspective view of a further specific implementation of the device of FIG. 1 herein;
FIG. 11 herein is a cross sectional side elevation view of the device of FIG. 10 herein;
FIG. 12A herein is a perspective view of an insert capable of use with the device of FIG. 10 herein; and
FIG. 12B herein is a cross sectional side elevation view of the insert of FIG. 12A herein.
DETAILED DESCRIPTION OF THE INVENTION
There will now be described by way of example a specific mode contemplated by the inventors. In the following description numerous specific details are set forth in order to provide a thorough understanding. It will be apparent however, to one skilled in the art, that the present invention may be practiced without limitation to these specific details. In other instances, well known methods and structures have not been described in detail so as not to unnecessarily obscure the description.
Within this specification, the term ‘reaction plate’ includes a magnetic stirrer plate; a hotplate and; a magnetic stirrer hotplate typically found within the art and used within a laboratory environment to provide heat or a stirring effect to a reaction medium housed within a reaction vessel.
Within this specification, reference to the central positioning of the flask, insert or recessed portion of the base unit relative to the reaction plate includes an alignment of a central point of the flask, insert or recessed portion with a central point of the reaction plate. Additionally, ‘centrally’ includes the relative positioning of the flask, insert or recessed portion within the perimeter of the reaction plate such that the majority of the flask, insert or recessed portion is positioned within the perimeter of the reaction plate.
FIG. 1A herein illustrates a perspective view of the reaction vessel support device according to the specific implementation of the present invention and FIG. 2 herein illustrates a cross sectional perspective view of the device.
Referring to FIGS. 1 and 2 herein, reaction station 100 comprises a reaction plate 101 comprising a substantially circular upper working surface (not shown). Reaction plate 101 is formed at one end of a neck portion 108 extending from a substantially rectangular upper surface 111 of reaction station 100 . Suitable control means are provided 106 , 107 allowing a user to adjust the heating effect provided at hotplate 101 and control the extent of the magnetic field generated in the region of the hotplate.
The reaction vessel support device comprises a base unit 102 comprising a bowl-like configuration in which a central recessed portion (not shown) accommodates a dish-like insert 103 . A reaction flask 104 is seated within and supported by insert 103 via a concave receiving portion 206 corresponding in shape, dimension and/or curvature to an exterior, lower portion of reaction vessel 207 .
Insert 103 comprises an annular lip portion 203 located at an upper region of the concave inner surface 206 . Lip 203 is configured to seat onto an upper portion of the recessed portion of base unit 102 whereby insert 103 may be suspended via lip 203 . According to the specific implementation of the present invention a gap of substantially 2 mm is provided between the outer convex surface region of the dish-like insert and the surface region of the recessed portion provided within base unit 103 .
Two handles 105 are provided at base unit 102 , the handles being positioned at opposite sides of the base unit substantially opposed to one another. Each handle comprises a projection (not shown) comprising screw threads configured to mate with corresponding screw threads (not shown) provided within unit 102 .
A slim elongate cavity 109 is provided in an upper region of base unit 102 configured to receive and accommodate a portion of a liquid filled thermometer. A similar additional cavity is provided 110 configured to receive and accommodate an electronic temperature probe, being for example a metal-resistance thermometer.
Referring to FIG. 2 herein a magnet 200 is housed within a cavity 202 extending from an underside surface 208 of reaction station 100 to the reaction plate 101 . A spindle 201 connects magnet 200 to a motor (not shown) whereby magnet 200 , positioned directly below reaction plate 101 , is rotatable in the plane of plate 101 so as to generate a magnetic field within the region of reaction station 100 . A magnetised stirrer bar (not shown) accommodated within reaction vessel 104 is caused to rotate in response to the magnetic field.
Base unit 102 comprises an annular groove 204 formed within its exterior surface positioned midway between an upper and lower portion. Groove 204 is configured to receive suitable means for locating a heat shield at the exterior surface of base unit 102 . The heat shield is configured to conceal substantially the entire external surface of unit 102 and is preferably manufactured from a thermally insulating material.
FIGS. 3 , 4 and 5 herein illustrate respectively a perspective view, a plan view and a cross sectional side elevation view of the base unit 102 of FIGS. 1 and 2 herein.
Base unit 102 comprises a substantially centrally positioned recessed portion 300 extending inwardly from an upper region towards a lower region to define a bowl-like cavity. With reference to FIG. 5 herein the recessed portion 300 comprises an annular side wall 500 extending towards the lower region of a base unit to form a cavity base 501 . The internally concave recessed portion 300 borders, at an upper region, the outer surface of the base unit via an annular chamfered section 502 . This upper region and/or chamfered section 502 is configured to seat annular lip 203 ( FIG. 2 ) so as to suspend insert 103 within recessed portion 300 .
A further cavity 503 is provided at a lower region of base unit 102 . Cavity 503 comprises a substantially cylindrical configuration being open at one end 506 , at bottom surface 208 of base unit 102 . Cavity 503 is defined by annular wall 504 extending inwardly from base surface 208 towards the substantially circular innermost wall 505 positioned directly underneath recessed portion 300 . Via cavity 503 , base unit 102 is capable of seating at the reaction plate ( FIG. 2 ) whereby lateral movement of base unit 102 is impeded or preferably prevented. Base unit 102 may be displaced from reaction plate 101 by a user grasping handles 105 and lifting the device upwardly in a direction perpendicular to surface 111 of reaction station 100 .
FIGS. 6A and 6B illustrate a perspective view and cross sectional side elevation view of an insert capable of seating within recessed portion 300 . The dish-like insert comprises an internally concave surface region 601 , 602 , 603 and an externally convex surface region 604 having a profile corresponding to a segment of a sphere. A portion of the inner, concave region comprises reaction vessel receiving portion 602 capable of seating and locating about a lower portion of a reaction vessel or flask 104 . The curved vessel receiving portion 602 is bordered at its uppermost region 603 by an annular inclined wall 601 tapering outwardly from the concave bowl 602 towards an upper region of the insert. The tapered annular wall 601 terminates at an annular upper surface 605 which defines a portion of annular lip 600 .
FIGS. 7A and 7B herein illustrate a perspective view and cross sectional side elevation view of a slightly modified version of the insert of FIGS. 6A and 6B herein. The insert of FIGS. 7A and 7B herein is configured for supporting a larger reaction vessel than that of the insert of FIGS. 6A and 6B herein. In particular, a radius of curvature of concave reaction vessel receiving portion 702 is greater than region 602 such that a vessel of larger width or diameter may be accommodated within the insert. Similarly, FIGS. 8A and 8B herein illustrate a further variation of insert configured to accommodate a larger reaction vessel than the insert of FIGS. 7A , 7 B and 6 A, 6 B herein. The radius of curvature of vessel receiving portion 802 is greater than that of the respective receiving portions 702 , 602 . Additionally, the depth of the vessel receiving portion 802 of the insert of FIG. 8 herein is greater than that of the insert of FIGS. 7A , 7 B and 6 A, 6 B herein.
The annular tapered side wall 601 , 701 allows enhanced visibility of the reaction flask and hence the flask contents when seated within the insert and positioned at the device.
FIG. 9 herein illustrates the heating performance of the base unit according to the specific implementation of the present invention comprising an insert configured to seat a 1 litre flask. The heating performance was evaluated using a fuzzy logic temperature controller both in the block and in the flask. The flask was filled with water to half the total flask volume. The water was stirred using an electrical stirring bar and the oil bath was stirred using a cross shaped stirring bar. Temperatures were measured via the fuzzy logic probe and a separate temperature check thermometer as appropriate. A Heidolph oil bath and a Heidolph MR 3001 K stirring hotplate were used.
The fuzzy logic probe, positioned within the base unit and the oil bath, was set to 140° C. The internal flask temperature was monitored by the temperature check thermometer.
Curve 900 represents the temperature of the water within the flask supported by the present invention; curve 901 represents the temperature of the water within the flask partially submerged within the oil bath; curve 902 represents the temperature of the base unit and; curve 903 represents the temperature of the oil within the oil bath.
As illustrated, the reaction vessel support device and the oil bath behave very similarly as confirmed by the change in temperature over time of both the base unit/oil bath and the water in both flasks. Both the device of the present invention and the oil bath brought the water, within the flask, to the boil after approximately 39 minutes.
FIGS. 10 and 11 herein illustrate respectively perspective and cross sectional side elevation views of a further specific implementation of the base unit of FIGS. 1 to 5 herein. The base unit 1000 comprises centralised cavity 1001 being defined by concave wall 1100 and base 1101 . Annular rim 1006 borders the cavity opening and comprises recessed portions 1002 , 1003 configured to receive a thermometer and temperature probe, respectively. Handle receiving means 1004 are provided through the body of the base unit for receiving handles 105 (not shown) annular groove 1005 extending around the perimeter of the base unit is capable of receiving the heat shield as described with reference to FIGS. 1 to 4 herein. Cavity 1103 being defined by walls 1104 , 1105 is capable of locating about hotplate 101 received through open end 1106 as detailed with reference to FIG. 5 herein.
FIGS. 12A and 12B herein illustrate respectively a perspective view and a cross sectional side elevation view of an insert configured for seating within the base unit of FIGS. 10 and 11 herein. The insert comprises internally concave surface region 1202 being defined by annular side wall 1203 and base 1204 . Side wall 1203 is bordered at its upper region by outwardly tapering annular side wall 1206 positioned between an upper flat annular surface 1207 and an annular end region 1205 of curved wall 1203 . Lip 1200 is configured for positioning and seating at upper surface 1006 of the base unit. The exterior, convex, bowl-like surface 1208 comprises a curvature configured to correspond to that of the cavity 1001 of base unit 1000 .
Annular lip 1200 comprises two cut-out sections 1201 positioned opposed to one another wherein when insert is seated within recessed portion 1001 thermometer receiving means 1002 , 1003 are not concealed.
According to further specific implementations of the present invention cavity 503 , 1103 may be replaced by a plurality of, in particular three or four, projections extending from lower surface 208 . The projections, distributed around the perimeter of surface 208 , are spaced apart sufficiently such that each projection is configured to grip the perimeter of the hotplate 101 as the base unit is seated at reaction station 100 .
Although the invention has been described and illustrated with respect to exemplary embodiments thereof, it should be understood by those skilled in the art that the foregoing and various other changes, omissions and additions may be made therein and thereto, without parting from the spirit and scope of the present invention. | A reaction vessel support device for mounting on a magnetic stirrer hotplate. The modular device comprises a base unit capable of positioning and seating at the reaction hotplate, and an insert formed non-integrally with the base unit comprising a reaction vessel receiving portion capable of seating and locating about a portion of a reaction vessel. At any one time, the base unit is capable of accommodating a plurality of different shaped and sized inserts each insert being configured to seat and support a specific reaction vessel of particular shape and size. The device therefore serves as a magnetic stirrer hotplate adapter. | 1 |
TECHNICAL FIELD
[0001] The present invention relates to an apparatus for the treatment of a fluid, such as for example air or water, and the detection of fluid contamination. In particular, the present invention relates to the use of a dual wavelength emitting laser in an apparatus for the treatment of air or water and the detection of airborne or waterborne contamination. The invention may be applied to a product which purifies air and confirms whether or not the air is safe to breathe. The invention also may be applied to a product which purifies drinking water and confirms whether or not the water is safe to drink.
BACKGROUND ART
[0002] There is an ever increasing need for clean and safe air to breathe and water to drink, particularly in heavily populated countries or regions throughout the world. A major, high-volume, application for compact solid-state deep ultraviolet (UV-C) light sources is for chemical-free sterilisation of air or water. UV-C light causes permanent physical damage to DNA which prevents bacteria, viruses and fungi from replicating. This means that UV-C treatment can be used to disinfect air or water at points-of-use for safe breathing or drinking. UV-C light is particularly effective at destroying the e-coli bacteria.
[0003] Compact solid-state UV-C light sources also have application in bio- and chemical-sensing because biological and chemical compounds strongly absorb UV-C light. Proteins and other organic chemicals can be identified from their fluorescence spectra. A fluorescence measurement requires illumination with light at a short wavelength at which the compounds are strongly absorbing, and detection of the resulting fluorescence at longer wavelengths. Wavelengths near about 280 nm are suitable, but shorter wavelengths of about 220 nm are preferred owing to the stronger absorbance at this wavelength.
[0004] Point-of-use products for the UV-C treatment of air and water are already available, and these products use mercury lamps as the UV light source. However, mercury lamps contain toxic material, tend to have short operating lifetimes and long warm-up times. An alternative UV light source currently under development is the UV semiconductor light emitting diode (LED). The current drawbacks to using UV LEDs are again lifetime issues, their poor performance below a wavelength of 260 nm and their inability to provide a collimated beam or tightly focused light spot. UV-C lasers, on the other hand, potentially provide a monochromatic, coherent, collimated and easily focusable beam which can be rapidly modulated for fluorescence measurements. UV-C lasers also emit at wavelengths down to 205 nm.
[0005] A UV-C laser can be realised by frequency doubling a blue-violet wavelength laser diode. Nishimura, JJAP 42, 5079 (2003) reported on making a UV-C laser in this way. An advantage of using a UV-C laser made by frequency doubling is that the device can be made to emit both the UV-C laser light (205-230 nm) and the blue-violet laser light (410-460 nm). The two wavelengths of light are particularly useful in a sensor system for distinguishing between micro-organisms of different species and size.
[0006] Several systems for the detection and treatment of micro-organisms in air using UV lasers are disclosed in the following:
[0007] Yoshinaga et al., U.S. Pat. No. 5,123,731, issued on Jun. 13, 1992, discloses a particle measuring device which uses two laser wavelengths through frequency doubling a first laser beam. The use of laser wavelengths down to 200 nm are specified; however, no mention of air treatment is made in this patent, and the system does not provide treatment of the particles.
[0008] Silcott et al., U.S. Pat. No. 7,106,442, issued on Sep. 12, 2006, discloses another particle measuring device which uses multiple laser beams of different wavelengths, including frequency doubled laser beams. Treatment of the particles is not mentioned in this patent.
[0009] Wilson et al., U.S. Pat. No. 7,242,009, issued on Jul. 10, 2007, discloses a method of using multiple wavelength laser induced fluorescence to distinguish between threat and background airborne particles. Again, no method of treating the threat particles is disclosed.
[0010] Berry et al., WO2004110504A2, published on Dec. 23, 2004, is an air sterilising system which uses a UV laser. The use of multiple laser wavelengths is specified, but only in a discrete narrow range. The system does not provide sensing.
[0011] Zamir, WO2005011753A1, published on Feb. 10, 2005, discloses another system for sterilising liquids and gases using a UV laser. Only UV light is used, and there is no sensing of micro-organisms.
[0012] Several systems for the treatment and detection of micro-organisms in water using UV lasers are disclosed in the following:
[0013] Baca et al., U.S. Pat. No. 6,919,019B2, issued on Jul. 19, 2005, discloses a laser water detection and treatment system for the military. However, this system has micro-organism sensing which is separate from the water treatment zone, and a laser is not used for the sensing of micro-organisms. Both of these issues will increase the size and cost of such a system.
[0014] Goudy, Jr., U.S. Pat. No. 4,816,145, issued on Mar. 28, 1989, discloses a system for the laser disinfection of fluids. The device disinfects water using a UV (gas) laser and sensors to adjust the laser power to compensate for scattering. Only one laser wavelength is used (UV), and the detectors do not distinguish between scattering, absorption and fluorescence. Again, the size and cost of such a system are likely to be problematic. Also, the sensitivity and range of the detector will be limited in this device.
[0015] Baca, U.S. Pat. No. 6,740,244B2, issued on May 25, 2004, discloses another laser water treatment system that disinfects water near point-of-use using a UV laser. Only a UV laser is used, and there is no sensing in this device.
[0016] Safta, U.S. Pat. No. 6,767,458B2, issued on Jul. 27, 2004, discloses another water purification system using only a UV laser. However, it does not have sensing.
[0017] Killinger et al., U.S. Pat. No. 7,812,946, issued on Oct. 12, 2010, discloses a water monitoring apparatus that includes a UV LED source to excite fluorescence from dissolved organic compounds. The use of a UV laser is mentioned but only as a performance comparison to the UV LED.
SUMMARY OF INVENTION
[0018] Aspects of the invention include a system for the disinfection of a flowing fluid, such as for example air or water, using ultraviolet laser light, and the determination of fluid (air or water) purity from detecting and comparing fluorescence, scattering and absorption of visible and ultraviolet laser light in the fluid (air or water) flow.
[0019] Exemplary embodiments of the invention include a laser light source simultaneously generating both visible and ultraviolet laser beams. Both laser beams are incident on a narrow stream of flowing fluid, such as for example air or water, containing micro-organism particulates. The micro-organisms mostly absorb the UV laser light, causing them to both fluoresce and be destroyed, and mostly transmit and scatter the visible blue-violet laser light. By detecting and comparing the fluorescence, absorption and scattering of the different laser beams, the air or water purity can be determined.
[0000] Advantages of the invention include:
a) The high efficacy of the UV-C laser wavelength for rapidly destroying bacteria, strongly exciting bacteria fluorescence and being strongly absorbed in contaminated water. b) The use of highly collimated and tightly focused laser beams for fast and effective water treatment and achieving high sensing signals from waterborne micro-organisms. c) Both the visible and UV laser beams are generated by the same light source. Therefore, component size, cost and power consumption is low. d) The two wavelengths of light are particularly useful in a sensor system for distinguishing between micro-organisms of different species and size.
[0024] Other exemplary embodiments of the present invention include a system with an apparatus having a conduit for directing a flow path of a fluid, such as air or water, containing biological particles at a constant velocity along a straight path, and a laser light source simultaneously emitting both an ultraviolet and a visible laser beam that is directed to be incident on the flow path of the air or water. The visible laser beam may be generated by a laser diode, and the ultraviolet laser beam may be generated by frequency doubling the visible laser beam using a non-linear optical crystal. The ultraviolet laser beam excites the biological particles to fluoresce and damage their DNA structure at the same time. The system may further include a sensor for measuring the scattered laser light from the biological particles in the directed flow path, a sensor for measuring the fluorescence from the biological particles in the flow path, and a sensor for measuring the transmission of laser light through the flow path to determine absorption of the laser light by the water or air. The system further may include a controller configured to determine whether contaminants are present in the fluid based upon the detections of the sensors.
[0025] Accordingly, an aspect of the invention is a system for purifying a fluid or determining fluid purity. An embodiment of the system includes a light source for generating a first laser light beam incident upon a flow path of the fluid, and a frequency doubler for doubling the frequency of at least a portion of the first laser light beam to generate a second laser light beam incident upon the flow path of the fluid, wherein the second laser light beam has a wavelength suitable for absorption by contaminants in the fluid. A plurality of light detectors detect at least one of the first laser light beam or the second laser light beam after the light beams exit the flow path. A controller is configured to determine whether contaminants are present in the fluid based upon the detections of the plurality of light detectors.
[0026] In another exemplary embodiment of the system, the first laser light beam is a visible laser light beam and the second laser light beam is an ultraviolet laser light beam.
[0027] In another exemplary embodiment of the system, the wavelength of the ultraviolet laser light beam is exactly half that of the visible laser light beam.
[0028] In another exemplary embodiment of the system, the ultraviolet laser beam has a wavelength of less than 270 nm.
[0029] In another exemplary embodiment of the system, the ultraviolet laser beam has a wavelength of less than 230 nm.
[0030] In another exemplary embodiment of the system, the ultraviolet laser beam has a wavelength of less than 210 nm.
[0031] In another exemplary embodiment of the system, the visible laser beam has a wavelength of less than 540 nm.
[0032] In another exemplary embodiment of the system, the visible laser beam has a wavelength of less than 460 nm.
[0033] In another exemplary embodiment of the system, the visible laser beam has a wavelength of less than 420 nm.
[0034] In another exemplary embodiment of the system, at least one of the light detectors is a scattering light detector that measures light scattered from the flow path.
[0035] In another exemplary embodiment of the system, at least one of the light detectors is a transmitted light detector that measures light transmitted through the flow path.
[0036] In another exemplary embodiment of the system, at least one of the light detectors is a fluorescence light detector that measures fluorescence from the flow path.
[0037] In another exemplary embodiment of the system, the first laser beam is a pulsating laser beam.
[0038] In another exemplary embodiment of the system, the system further includes a conduit defining the flow path of the fluid.
[0039] In another exemplary embodiment of the system, the conduit includes a plurality of optical window regions that are transparent to wavelengths of light corresponding to wavelengths of light of the first and second laser light beams.
[0040] In another exemplary embodiment of the system, the first and second laser light beams intersect the flow path at different points.
[0041] In another exemplary embodiment of the system, the fluid is contained in a vessel as a static volume flow path.
[0042] In another exemplary embodiment of the system, the light source includes a semiconductor laser diode for generating the first laser light beam.
[0043] In another exemplary embodiment of the system, the frequency doubler is a non-linear optical crystal.
[0044] In another exemplary embodiment of the system, the frequency doubler is a beta-Barium Borate non-linear optical crystal.
[0045] Another aspect of the invention is a method for purifying a fluid or determining fluid purity. An exemplary embodiment of the method may include the steps of generating a first laser light beam incident upon a flow path of the fluid; doubling the frequency of at least a portion of the first laser light beam to generate a second laser light beam incident upon the flow path of the fluid wherein the second laser light beam has a wavelength suitable for absorption by contaminants in the fluid; detecting at least one of the first laser light beam or the second laser light beam after the light beams exit the flow path; and determining whether contaminants are present in the fluid based upon the light detections.
[0046] In another exemplary embodiment of the method, the first laser light beam is a visible laser light beam and the second laser light beam is an ultraviolet laser light beam having half the wavelength of the first laser light beam.
[0047] In another exemplary embodiment of the method, the first and second laser light beams intersect the flow path at different points.
[0048] In another exemplary embodiment of the method, detecting at least one of the first laser light beam or the second laser light beam comprises at least one of detecting light that is scattered from the flow path, detecting light that is transmitted through flow path, or detecting light fluorescence from the flow path.
[0049] In another exemplary embodiment of the method, the fluid is at least one of air or water.
[0050] To the accomplishment of the foregoing and related ends, the invention, then, comprises the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative embodiments of the invention. These embodiments are indicative, however, of but a few of the various ways in which the principles of the invention may be employed. Other objects, advantages and novel features of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the drawings.
BRIEF DESCRIPTION OF DRAWINGS
[0051] FIG. 1 is a schematic diagram depicting an air or water purification and sensor system according to an exemplary embodiment of the invention.
[0052] FIG. 2 is a top plan view of the component configuration of a UV laser made by frequency doubling a blue-violet laser light beam from a laser diode.
[0053] FIG. 3 is a graphical representation of the actual light output produced by a dual wavelength laser where the UV laser beam (b) is made by frequency doubling a blue-violet laser diode beam (a).
[0054] FIG. 4 is a schematic diagram depicting a water purification and sensor system according to an exemplary embodiment of the invention.
[0055] FIG. 5 is a schematic diagram depicting an air purification and sensor system according to another exemplary embodiment of the invention.
[0056] FIG. 6 is a schematic diagram depicting a static purification and sensor system according to another exemplary embodiment of the invention.
DESCRIPTION OF REFERENCE NUMERALS
[0000]
1 Dual wavelength laser source
1 a Laser diode
1 b Frequency doubling (FD) crystal
2 Flow conduit containing air or water stream
2 a Flow conduit containing water stream
2 b Flow conduit containing air stream
3 Light detectors
3 a Light detector to measure laser light scattered from the flow stream
3 b Light detector to measure laser induced fluorescence from the flow stream
3 c Light detector to measure laser light transmitted through the flow stream
4 Treatment vessel containing volume of air or water
5 Conduit optical window region
6 Vessel optical window region
7 Controller
DETAILED DESCRIPTION OF INVENTION
[0071] Referring to FIGS. 1 and 2 , the present invention uses a dual wavelength laser 1 made by frequency doubling a first visible laser light beam from a semiconductor laser diode 1 a to generate a second ultraviolet laser light beam. The frequency doubling is achieved using a frequency doubler in the form of, for example, a non-linear optical frequency doubling (FD) crystal 1 b . FIG. 2 illustrates a top plan view of a dual wavelength laser component 1 made by frequency doubling a blue-violet laser beam.
[0072] The first blue-violet laser light beam may be generated by a blue-violet laser diode 1 a and may have a wavelength in the range 410 to 460 nm. Green laser diodes with wavelengths as long as 540 nm are also suitable. The monochromatic blue-violet laser beam is shaped and focused into a frequency doubler, such as a non-linear optical FD crystal 1 b that may be made of beta-Barium Borate (BaB 2 O 4 or BBO) with a pre-determined crystal cut, orientation and geometric shape. The BBO FD crystal frequency doubles the input laser beam to produce the second ultraviolet output laser light beam with double the frequency (or half the wavelength). For example, an input laser beam of 460 nm will produce an output laser beam of 230 nm. As depicted in FIG. 1 , for example, only a percentage of the input beam is frequency doubled, and the remainder passes straight through. For example, one component of the outputted beam may be the first blue-violet laser light beam, and another component of the outputted beam may be the second ultraviolet (UV) laser light beam with double the frequency (half the wavelength) of the first blue-violet laser beam. Therefore, the output from the BBO FD crystal contains a pair of beams with two different laser wavelengths (the input and the frequency doubled components). The second UV laser light beam typically would be of wavelength suitable for purifying the air or water, in that biological contaminants may absorb light from the UV laser light beam and be destroyed.
[0073] In an exemplary embodiment, the BBO FD crystal may be placed inside a re-circulating optical cavity which allows multiple passes of the incident blue-violet laser beam through the BBO FD crystal, thereby increasing the total amount of blue-violet light converted into UV light. In addition, one may increase the total amount of blue-violet light converted into UV light by mechanically shaping the BBO FD crystal into a ridge waveguide structure with dimensions of several micrometers in directions orthogonal to the blue-violet laser beam and several millimeters in the same direction as the blue violet laser beam.
[0074] FIG. 3 shows the optical spectra from a dual wavelength laser 1 made by frequency doubling a single beam pass of a blue-violet laser diode 1 a through a BBO FD crystal 1 b . The blue-violet laser diode can be modulated or pulsed at very high speed; therefore, the UV laser beam can also be modulated at the same speed. The UV laser beam (b) is essentially half the wavelength of the blue-violet laser beam (a).
[0075] Examples of the operation of the present invention are described below. Although the invention is described principally in connection with the purification and detection of contaminants in air or water, it will be appreciated that the invention is not limited in such regard. Rather, the invention may be utilized in connection with any suitable fluid (the term fluid being understood to include both liquids and gases).
Example 1
[0076] An exemplary preferred embodiment of the present invention is now described with reference to FIG. 4 . The system illustrated in FIG. 4 includes a conduit 2 a that provides a flow path through which a steady flow of water passes. A conduit diameter in the range 1 to 10 mm is preferred, and 3 mm is most preferred. A water flow in the range 0.1 to 3 litres per minute is preferred, and 1 litre per minute is most preferred. The conduit contains an optical window region 5 that is transparent to light in the wavelength range between about ultraviolet and infrared, and thus is transparent to wavelengths of light of the first blue-violet laser light beam and the second ultraviolet laser light beam. The optical window region 5 , for example, may be crystal quartz.
[0077] The pair of laser beams provided by the dual wavelength laser component 1 are split and then directed onto the water flow via the optical window region. The UV laser beam typically will be absorbed by any biological particles or micro-organisms in the water causing them to fluoresce. The DNA structure of the biological particles typically will also be physically damaged or destroyed by the UV light. Some of the UV laser beam will also scatter off the particles or pass through the water (depending on its purity). Most of the blue-violet laser beam typically will either pass through the water or scatter off the particles. However, some particle fluorescence may also be induced by the blue-violet laser beam.
[0078] A plurality of light detectors 3 are positioned to receive light that exits the flow path from the optical window region 5 of the water conduit. For example, the light detectors 3 may include detectors to measure the light scattering (detector 3 a ), fluorescing (detector 3 b ) or light being transmitted (detector 3 c ) by any biological particles in the water (which in turn may be used to determine absorption). CCD sensors are preferred detectors due to their compact size. Optical filters may also be used to distinguish between signals. Pulsing the laser beams may be employed as the input light signals. The type, size, and number of biological particles in the water stream may be determined by detecting and comparing the corresponding scattering, fluorescence and transmission signals.
[0079] The conduit 2 a may contain several optical window regions 5 for light to exit the water flow that are not adjacent to the entry window. This provides a means for the UV laser beam to experience multiple reflections inside the conduit before exiting, thereby increasing its germicidal effectiveness in destroying any micro-organisms.
[0080] A controller 7 receives and processes outputs from the plurality of light detectors 3 . The controller 7 is configured to determine whether contaminants are present in the water based upon the detections of the plurality of light detectors 3 . More specifically, the controller 7 may compare the outputs of the light detectors 3 against a library of stored reference signals produced by known contaminants. In this way, contaminant species can be identified and quantified. Optical filters may be employed in conjunction with the light detectors 3 so as to improve signal to noise ratio. The controller 7 may be provided in the form of a control circuit or processing device that may execute program code stored on a machine-readable medium. Such controller functionality could also be carried out via dedicated hardware, firmware, software, or combinations thereof, without departing from the scope of the invention.
Example 2
[0081] Another exemplary preferred embodiment of the disclosed system is illustrated in FIG. 5 . The embodiment of FIG. 5 includes conduit 2 b that provides a flow path through which a steady flow of air passes. A conduit diameter in the range 1 to 10 mm is preferred, and 3 mm is most preferred. An air flow in the range 0.1 to 3 litres per minute is preferred, and 1 litre per minute is most preferred. The conduit contains an optical window region 5 that is transparent to light in the wavelength range between ultraviolet and infrared, and thus is transparent to wavelengths of light of the first blue-violet laser light beam and the second ultraviolet laser light beam. The optical window region 5 , for example, may be crystal quartz.
[0082] The pair of laser beams provided by the dual wavelength laser component 1 are split and then directed onto the air flow via the optical window region. The UV laser beam typically will be absorbed by any biological particles or micro-organisms in the air causing them to fluoresce. The DNA structure of the biological particles typically will also be physically damaged or destroyed by the UV light. Some of the UV laser beam will also scatter off the particles or pass through the air (depending on its purity). Most of the blue-violet laser beam typically will either pass through the air or scatter off the particles. However, some particle fluorescence may also be induced by the blue-violet laser beam.
[0083] A plurality of light detectors 3 are positioned to receive light that exits the flow path from the optical window region of the air conduit. For example, the light detectors 3 may include detectors to measure the light scattering (detector 3 a ), fluorescing (detector 3 b ) or being transmitted (detector 3 c ) by any biological particles in the air (which in turn may be used to determine absorption). CCD sensors are preferred detectors due to their compact size. Optical filters may also be used to distinguish between signals. Pulsing laser beams may be employed as the light input signal. The type, size and number of biological particles in the air stream may be determined by detecting and comparing the corresponding scattering, fluorescence and transmission signals.
[0084] The conduit 2 b may contain several optical window regions 5 for light to exit the air flow that are not adjacent to the entry window. This provides a means for the UV laser beam to experience multiple reflections inside the conduit before exiting, thereby increasing its germicidal effectiveness in destroying any micro-organisms.
[0085] As in the previous example, a controller 7 receives and processes outputs from the plurality of light detectors 3 . The controller 7 is configured to determine whether contaminants are present in the air based upon the detections of the plurality of light detectors 3 .
Example 3
[0086] Another exemplary preferred embodiment of the disclosed system is illustrated in FIG. 6 . The embodiment of FIG. 6 includes a vessel 4 which is periodically filled and emptied with a volume of air or water, and in which the volume of air or water is held for germicidal treatment and detection. A vessel volume in the range 10 to 1000 mm 3 is preferred, and 125 mm 3 is most preferred. The vessel contains optical window regions 6 that are transparent to light in the wavelength range between ultraviolet and infrared, and thus is transparent to wavelengths of light of the first blue-violet laser light beam and the second ultraviolet laser light beam. The optical window region 6 , for example, may be crystal quartz.
[0087] The pair of laser beams provided by the dual wavelength laser component 1 are split and then directed onto the air or water volume via the optical window region. The UV laser beam typically will be absorbed by any biological particles or micro-organisms in the air/water causing them to fluoresce. The DNA structure of the biological particles typically will also be physically damaged or destroyed by the UV light. Some of the UV laser beam will also scatter off the particles or pass through the air/water (depending on its purity). Most of the blue-violet laser beam typically will either pass through the air/water or scatter off the particles. However, some particle fluorescence may also be induced by the blue-violet laser beam.
[0088] A plurality of light detectors 3 are positioned to receive light that exits the vessel from the optical window region 6 of the air/water vessel. For example, the light detectors 3 may include detectors to measure the light scattering (detector 3 a ), fluorescing (detector 3 b ) or being transmitted (detector 3 c ) by any biological particles in the air or water (which in turn may be used to determine absorption). CCD sensors are preferred detectors due to their compact size. Optical filters may also be used to distinguish between signals. Pulsing laser beams may be employed as the input light signal. The type, size and number of biological particles in the air/water volume may be determined by detecting and comparing the corresponding scattering, fluorescence and transmission signals.
[0089] The vessel 4 may contain several optical window regions 6 for light to exit the air/water that are not adjacent to the entry window. This provides a means for the UV laser beam to experience multiple reflections inside the vessel before exiting, thereby increasing its germicidal effectiveness in destroying any micro-organisms.
[0090] As in the previous examples, a controller 7 receives and processes outputs from the plurality of light detectors 3 . The controller 7 is configured to determine whether contaminants are present in the air or water based upon the detections of the plurality of light detectors 3 .
[0091] Once germicidal treatment of the air/water volume is completed, the vessel 4 may be emptied into another vessel ready for safe use, and the first vessel 4 may then be refilled with a new volume of air/water for treatment and sensing.
[0092] Although the invention has been shown and described with respect to a certain embodiment or embodiments, equivalent alterations and modifications may occur to others skilled in the art upon the reading and understanding of this specification and the annexed drawings. In particular regard to the various functions performed by the above described elements (components, assemblies, devices, compositions, etc.), the terms (including a reference to a “means”) used to describe such elements are intended to correspond, unless otherwise indicated, to any element which performs the specified function of the described element (i.e., that is functionally equivalent), even though not structurally equivalent to the disclosed structure which performs the function in the herein exemplary embodiment or embodiments of the invention. In addition, while a particular feature of the invention may have been described above with respect to only one or more of several embodiments, such feature may be combined with one or more other features of the other embodiments, as may be desired and advantageous for any given or particular application. | A system and method are disclosed for the simultaneous optical disinfection and detection of biological particles in a flowing fluid, such as air or water, medium. A light source for irradiating the flowing medium is a dual wavelength laser element simultaneously emitting a visible laser beam and an ultraviolet laser beam. In particular, a laser diode may generate a first visible laser light beam, and a second ultraviolet laser light beam may be generated by passing the first laser light beam through a frequency doubling crystal. Optical detectors measure scattering, fluorescence and/or transmission of the laser light beams from the air or water medium to determine the presence of biological particles in real-time. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an inorganic article for containing or contacting a solution for crystal growth of a compound semiconductor and a liquid-phase epitaxy apparatus using the same.
2. Description of the Prior Art
There are various types of inorganic devices used for the crystal growth of a compound semiconductor, including a carbon boat (a graphite boat), a container (a crucible), and a lid of the container, which are commonly made of graphite and employed where airtightness is required.
For example, the carbon boat is generally used in a slide boat procedure employed for liquid-phase epitaxy method of the epitaxial growth technology.
In operation of the liquid phase epitaxy, a solution for epitaxial growth is heated to a high temperature (of 700° to 900° C.) and then, cooled down. The solution contains diffusive elements having a high vapor pressure, such as arsenic, phosphorus, and the like and also, the carbon boat must be used in an airtight situation. However, the graphite is generally porous and the carbon boat made of the graphite has a large number of tiny pores on the surface thereof and, thus is unsatisfactory in the airtightness.
As a result, such diffusive elements tend to be dispersed through the tiny pores to the outside of the boat, whereby the stoichiometric composition of the solution will be destroyed causing structural defects of crystals. This disadvantage will become more serious during a longer period of the crystal growth.
The above-mentioned problems related to porousness also apply to porous inorganic structures in general, such as vessels made from graphite or ceramic (e.g. h-BN, Al 2 O 3 , etc.) exemplified by a crucible, lid of vessels and so on.
SUMMARY OF THE INVENTION
A primary object of the present invention is, in view of the aforementioned aspects, to provide a novel inorganic article for crystal growth and more specifically, an inorganic article for growth of crystals on a compound semiconductor in which the dispersion of diffusive elements contained in a solution for epitaxial growth from the tiny pores of the porous inorganic article is prevented.
Another object of the present invention is to provide a liquid-phase epitaxy apparatus in which the dispersion of diffusive elements contained in a solution for epitaxial growth from said apparatus to the outside during the process of epitaxial growth, which has been conventionally observed is prevented.
The first object is achieved by 1 an inorganic article for crystal growth, characterized in that the pores of a porous inorganic structure used for the substrate of the article for crystal growth are filled with an inorganic material having a melting point of 400° to 900° C. and also, 2 an inorganic article for crystal growth characterized in that the surface and about the pores of the article 1 is coated with amorphous carbon or diamond.
The second object is achieved by a liquid-phase epitaxy apparatus according to the present invention which comprises the following arrangements 3 or 4.
The arrangement 3 is characterized by comprising a crucible made of the inorganic article 1 or 2 or from a material selected from P-BN (pyrolytic boron nitride), quartz and sapphire, in which a substrate holder is disposed in the crucible, and a sealing member is arranged to suspend above the substrate holder, for trapping a solution contained above or beneath the substrate holder at said place.
Also, the arrangement 4 is characterized by comprising a crucible made of the inorganic article 1 or 2 or from a material selected from P-BN, quartz and sapphire, in which a source crystal holder is disposed in the bottom of the crucible, a substrate holder is arranged above and at a specific distance from the source crystal holder, and a sealing member is arranged to suspend above the substrate holder for trapping a solution contained between the two holders at said place.
According to the inorganic article 1 or 2 of the present invention, the pores of a substrate having a porous inorganic structure are closed with the particular inorganic material so that the permeability of vapor is sharply declined, whereby the dispersion of diffusive elements contained in the growth solution from the pores to the outside will be prevented as the airtightness is improved.
Particularly, the surface and the pits of the inorganic article 2 which has had the pores closed with the inorganic material are additionally coated with amorphous carbon or diamond so that the wear resistance is increased while the vapor permeability is further decreased as compared with the article 1, whereby the generation of carbon dust will be minimized.
Also, each of the apparatuses 3 and 4 of the present invention is comprised of the crucible made of the inorganic article 1 or 2 or from a material selected from P-BN, quartz and sapphire and has a crucible-like arrangement which provides nearly no sliding contact between the sliding parts and the stationary parts as compared with conventional slide type or piston type boat made from graphite. Hence, the dispersion of diffusive elements contained in the growth solution during the process of epitaxial growth is prevented since the airtightness is improved.
The porous inorganic structures associated with the present invention include various types of porous (or multi-cellular) structures employed for crystal growth of a compound semiconductor which are made of e.g. graphite or ceramic (h-BN, Al 2 O 3 , etc).
The inorganic material for filling into the pores of the porous inorganic structure of the inorganic article 1 or 2 according to the present invention may be selected without specific limitation, except that the melting point is 400° to 900° C., preferably, 450° to 850° C. and that no chemical reaction with a basic material such as graphite, ceramic and the like nor dissolution into the solution during the liquid phase epitaxy process is allowed. The inorganic materials thus include elements such as Al, Sb, Ba, and Ce, oxides such as B 2 O 3 , Bi 2 O 3 , Sb 2 O 3 , V 2 O 5 , MoO 3 , Rb 2 O 2 , and KReO 4 , halides such as CaCl 2 , EuBr 2 , EuI 2 , LaBr 3 , KCl, PrBr 3 , PrCl 3 , SmBr 2 , SmI 2 , AgCl, AgI, YbCl 2 , PbF 2 , LiBr, LiCl, MgCl 2 , MnCl 2 , RbBr, BbI, and NaI, and other compounds such as Sb 2 S 3 , Li 2 CO 3 , and NaCN.
Also, it is preferred that the inorganic material has a boiling point of not less than 1500° C. and more specifically, 1500° to 2250° C. and is less volatile. The inorganic materials satisfying the foregoing conditions include elements such as Al, Sb, Ba, and Ce, oxides such as B 2 O 3 , Bi 2 O 3 , Sb 2 O 3 , and V 2 O 5 , and halides such as CaCl 2 , EuBr 2 , EuI 2 , LaBr 3 , KCl, PrBr 3 , PrCl 3 , SmBr 2 , SmI 2 , AgCl, AgI, and YbCl 2 .
Among the most preferable inorganic materials having desired melting and boiling points are such common oxides as B 2 O 3 , Bi 2 O 3 and Sb 2 O 3 , of which melting and boiling points are 450° C. and 2250° C., 825° C. and 1890° C., and 656° C. and 1550° C. respectively.
Although the aforementioned inorganic materials suffice for use in the present invention, it is more preferable that in addition to a specific melting and boiling points, its vapor pressure be less than 5 mmHg at a temperature of 900° C. so that the dissipation of the inorganic material which has been filled in the article 1 from the tiny pores during the liquid phase epitaxy is minimized, and the addition thereof as an impurity to a growing crystal is decreased as much as possible.
The method of filling the pores of the porous inorganic structure with the inorganic material according to the present invention is not limited to the immersion process of immersing the structure into a solution of the inorganic material as described later and the process in which the pores are filled by applying a pressure at a high temperature after the structure is coated at surface with the inorganic material.
The coating with amorphous carbon or diamond over the surface and the pits of an article, for producing the article 2 is conducted after the pores are filled with the inorganic material, and any known coating method may be used with equal success. For example, a process using amorphous carbon may be applied in which the generation of amorphous carbon is carried out at the same time of the coating and more particularly, the coating with amorphous carbon is conducted by a plasma CVD method or common pyrolysis CVD with the use of a gas of carbon material such as hydrocarbon (e.g. methane, acetylene, propane, or butane), ketone (e.g. acetone), alcohol (e.g. methanol or ethanol), aromatic hydrocarbon (e.g. benzene or toluene), or the like. Other procedures including an ion beam sputtering with carbon target and a laser vapor deposition will also be used.
The methods of coating with diamond includes a heat filament method associated with a known thermal CVD apparatus provided with or utilizing a tungsten filament, a plasma CVD method employing a high frequency of not more than 13.5 MHz for energization under the almost same condition as of the thermal filament method, a procedure based on the thermal filament method in which the inorganic structure has a positive potential and between the structure and a filament a bias voltage is applied, a procedure using an ark plasma under about one atmospheric pressure, and a burning flame procedure in which mainly the mixed gas of methane-hydrogen or acetylene gas is burned in atmosphere with the aid of a burner and the inorganic structure cooled down is positioned in a flame for developing a layer of diamond thereon.
The foregoing procedures employ as the carbon material gas a mixture gas of hydrogen and carbon compound, e.g. methane, ethane, butane, ethylene, acetylene, ethanol, acetone, or carbon monoxide.
The thickness of an amorphous carbon or diamond layer may vary depending on the use and size of a component. For example, the layer on a carbon boat is preferably 0.1 to 50 μm, more specifically, 1 to 20 μm, and at optimum, about 5 μm.
The vapor permeability is hence remarkably decreased by additional coating with amorphous carbon or diamond as compared with that by simple filling of the tiny pores with inorganic material. In fact, the air permeability of an amorphous carbon layer is less than 10 -12 cm 2 /second under the conditions of He and ΔP=1 atm as compared with 0.1 to 10 cm 2 /second on a common carbon layer. The layer of diamond remains more stable at a higher temperature and higher in the wear resistance and the thermal conductivity than a layer of amorphous carbon.
The crucibles provided in the apparatuses 3 and 4 of the present invention are made of the article 1 or 2 or from a material selected from P-BN, quartz and sapphire. The articles 1 or 2 are much improved in the airtightness as described previously and also, each structure made from the material selected from P-BN, quartz and sapphire originally does not have pores which allow diffusive elements to escape, exhibiting a higher degree of airtightness. Hence, the shape of each crucible is not limited to a particular configuration. For example, a shape similar to that of a crucible used with a pulling method of a bulk crystal growing method may be employed.
The substrate holder and the source crystal holder arranged in a crucible are not limited to the article 1 or 2 of the present invention or an article made from the material selected from P-BN, quartz and sapphire and may be a common stable material such as graphite, ceramic (e.g. h-BN or Al 2 O 3 ), or the like, which undertakes no chemical reaction with a solution of the primary material. It is most preferable that they be the same article 1 or 2, or an article made from the material selected from P-BN, quartz and sapphire which are dense materials, as is the crucible, in order to improve airtightness.
The sealing member provided in the upper of a crucible is not particularly specified on condition that it does not allow the primary solution to pass through so that the dispersion of diffusive elements contained in the solution to the outside is prevented and causes no chemical reaction with the solution and the crucible, during the liquid phase epitaxy process. Preferably, a sealing liquid as the sealing member is selected from B 2 O 3 , BaCl 2 , CaCl 2 , Bi 2 O 3 , and Sb 2 O 3 for use with a bulk crystal growing method in e.g. the pulling method which employs a crucible.
The apparatuses 3 and 4 of the present invention are preferably employed for use with a liquid-phase epitaxy (LPE) method. Particularly, the apparatus 4 is most suitable for carrying out a yo-yo solute feeding method which is included in the LPE method. The yo-yo solute feeding method is such a procedure of production as disclosed in "Material for Light Emitting Device and its Production Method" (Japanese Patent Laid-open Publication Nos. 63-81989 (1988) and 61-226275 (1986)). The yo-yo method is named after the periodical increase and decrease of an operating temperature for growing a layer of desired crystal, which is based on the difference between densities of the solution and the solute contained in the solution at the gravity field.
By applying the apparatus 4 of the present invention to the yo-yo solute feeding method, the dispersion of diffusive elements contained in the solution can be avoided drastically even in a comparatively long period of epitaxial growth by the yo-yo method. In practice, the substrate holder arranged in the upper region of the apparatus has a substrate for crystal growth therein while the source crystal holder disposed in the lower region holds a source crystal therein to be a material and a space between the two holders is filled with the primary solution (See FIGS. 4 and 5).
In the present invention, elements with high vapor diffusion are those known in the epitaxial crystal growth technique for the manufacture of various compound semiconductor devices, which elements are exemplified by P, Zn, Se, S, As, etc. Examples of growth solutions containing these elements include GaP and InGaP for yellow-green LED; ZnSe, ZnS and ZnSSe for red LED; InP and GaAs for infrared LD and LED; and InGaAsP and InGaAs for other LDs. The components 1 and 2, and apparatuses 3 and 4 of the present invention can be used most effectively together with the growth solutions mentioned above.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic cross sectional view showing an equipment for filling the pores of an inorganic porous structure with an inorganic material for providing an article of the present invention;
FIG. 2 is a cross sectional view showing one embodiment of the apparatus 3 according to the present invention;
FIG. 3 is a cross sectional view showing another embodiment of the apparatus 3 according to the present invention;
FIG. 4 is a cross sectional view showing one embodiment of the apparatus 4 according to the present invention; and
FIG. 5 is a cross sectional view showing another embodiment of the apparatus 4 according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Hereunder, the article and the apparatus of the present invention will be described in detail by way of the embodiments.
First, the description will start with a carbon boat which is a typical porous inorganic structure, by referring to a method of filling a number of tiny pores existing in the carbon boat with an inorganic material and also, a method of coating with amorphous carbon and diamond. Both the shape and arrangement of the carbon boat are of conventionally known.
FIG. 1 illustrates an equipment for filling the inorganic porous substrate by an immersion procedure, in which there is provided a vacuum container 1of e.g. silica glass which is coupled with a conduit 2 communicated, in turn, with a vacuum pump (not shown) for rendering the vacuum container 1 vacuum, a conduit 3 for supplying a gas of e.g. N 2 , CO 2 , He, Ar or H 2 into the vacuum container 1, and a hanger rod 4 inserted thereinto for lifting upward and downward a carbon boat B in the vacuum container 1. A vessel 5 containing a solution 6 of the inorganic material is placed on the bottom of the vacuum container 1 so that the boat B can be immersed into the solution 6 by controlling the hanger rod 4. Also, an electric furnace 7 is provided around the vacuum container 1 for heating the boat B, vessel 5, and solution 6 in the vacuum container 1 to a high temperature.
The procedure for filling the tiny pores in the carbon boat B with the inorganic material using said device will now be described.
The vessel 5 is filled with the solution 6 of a desired inorganic material (e.g. B 2 O 3 ) and the carbon boat B to be processed is attached to the hanger rod 4. Then, the vacuum container 1 is airtightly closed andmade vacuum by sucking volatile substances therein through the conduit 2.
After the air is pumped out, the vacuum container 1 is heated by the electric furnace 7 to a proper temperature. This heat-up procedure can accelerate the effective removal of remaining gas or steam from the surface region and inside of the carbon boat B made from graphite by vacuum action. Also, by the heating, the inorganic material is melted downto a liquid and its viscosity can be lowered. For example, the viscosity ofthe inorganic material of e.g. B 2 O 3 is 3630 poise at 600°C. and reduced to 39.8 poise at 1200° C. Because the vapor pressure of the inorganic material increases with a rise in the temperature, a heating temperature can be adequately determined from the viscosity and the vapor pressure. For B 2 O 3 , the heating temperature is preferably 500° to 1500° C.
After the gas occluded in the carbon boat B is removed by heating and the inorganic material is heated to a predetermined temperature, the boat B isimmersed into the solution 6 by using the hanger rod 4 (as best shown in FIG. 1). Simultaneously, a gas of e.g. N 2 , CO 2 , He, Ar, or H 2 is introduced, as necessary, through the conduit 3 into the vacuumcontainer 1 for exerting pressure onto the solution 6 for adequate time so that the solution 6 can easily penetrate into the pores in the boat B.
The pressure to be applied may be any atmospheric pressure(s) as long as itsatisfies the object. For example, the pressure may be one atmospheric pressure, several atmospheric pressures or any other pressure besides these. While the vacuum container 1 remains at a give pressure with the introduction of gas after having a vacuum, the inorganic material is allowed to penetrate into the pores of the carbon boat B during a period of, for example, one minute to one hour. Thereafter, the boat B is lifted out of the solution 6.
The boat B is then removed out from the vacuum container 1 and the remaining solution on the surface of the boat B is removed off with the use of a solvent such as alcohol.
By the foregoing process, the carbon boat, the inorganic article 1 of the present invention, can be obtained. The inorganic article 2 according to the present invention is prepared by coating the article 1 with amorphous carbon or diamond.
The coating with amorphous carbon can be conducted by e.g. a plasma CVD method comprising the steps of baking a carbon boat filled with the inorganic material at 800° to 950° C. under the hydrogen atmosphere for several hours as a preparatory process, placing the boat B in a plasma reactor, introducing a mixture gas of argon and methane, CH 4 , for producing plasma, which serves as a hydrocarbon gas into thereactor, heating the boat B, if necessary, from the room temperature to about 150° C. and producing a plasma state in the reactor, and depositing amorphous carbon on the surface and the pits of the boat B. After the layer of amorphous carbon is developed to a desired thickness, the plasma state is released and the boat B is removed from the reactor. If necessary, a post-process is carried out by heating the boat B once more under the hydrogen atmosphere.
The coating with diamond is implemented by e.g. a plasma CVD method including after the same preparatory process as of amorphous carbon, the steps of placing a boat B in a plasma reactor, supplying with a mixture gas of methane and hydrogen, heating the boat B to 840° to 860° C., applying a high frequency of 13.5 MHz to the reactor for generating a plasma, and depositing a polycrystalline layer of diamond over the surface and the pits of the boat B. It is preferred that the plasma CVD method is carried out at a pressure of 10 to 100 Torr and with a concentration of methane gas of 0.5 to 5%.
Improved apparatuses 3 and 4 employing the foregoing inorganic components or other components made from a material selected from P-PN, quartz and sapphire will now be described.
An apparatus A for LPE is shown in FIG. 2 in which a substrate for crystal growth is placed beneath a solution. A substrate holder 11 for retaining the substrate 13 for crystal growth is disposed closely on the bottom of acrucible body 10.
Also, a sealing liquid 17 of e.g. B 2 O 3 is provided above and at a distance from the substrate holder 11 for trapping the solution 30 at said place.
Although not specifically explained in Figure, the liquid phase epitaxy with the apparatus A may be conducted by such an arrangement as shown in FIG. 3, which is associated with the pulling method of bulk crystal growth. In operation, the substrate 13 is placed on the substrate holder 11 and the solution 30 is supplied and sealed in with the sealing liquid 17 supplied on solution 30. Then, the solution 30 is heated to a temperature for starting the crystal growth and slowly cooled down to growthe crystals having a desired composition on the substrate 13. After the growth, the sealing liquid 17 and the solution 30 are discharged and the substrate 13 is taken out from the apparatus.
FIG. 3 illustrates an LPE apparatus B in which a substrate is disposed directly on the upper surface of a solution while a substrate holder is arranged to slide upward and downward. More particularly, the substrate holder 51 is slidably disposed in a crucible body 50. Also, a rod 59 is mounted to a central projection 51a of the substrate holder 51 so that thesubstrate holder 51 can be moved upward and downward from the outside of the apparatus. A sealing liquid 57 (of e.g. B 2 O 3 ) for trapping the solution 70 is provided above the substrate holder 51. As shown in Figure, the apparatus B is disposed on a base 92 arranged in a perpendicularly-disposed reactor 91 made from quarts, etc. as is common inthe pulling process of the bulk crystal growth. An electric furnace 93 extends around the reactor 91 in concentric circle.
In operation of the apparatus B for epitaxial growth, the substrate holder 51 is lifted down to the upper level of the solution 70 contained in the body 50 by actuating the rod 59 and simultaneously, the sealing liquid 57 is supplied onto the substrate holder 51. After heating the solution 70 toa temperature for starting crystal growth with the electric furnace 93, thesubstrate holder 51 is lowered by the rod 59 in order to allow the substrate 53 to come into contact with the upper surface of the solution 70. Then, the epitaxial growth is effected on the substrate 53 while slowly cooled down. After the epitaxial growth, the substrate holder 51 islifted up by the rod 59 to separate the substrate 53 from the solution 70.
Accordingly, the upward and downward movement of the substrate holder 51 bythe rod 59 allows the solution to come into contact with the substrate after heated up to the crystal growth starting temperature, thus minimizing the melt-back of the substrate into the solution and ensuring quick separation of the substrate from the solution after the crystal growth. Hence, the deposition of poly-crystal materials on the surface of a growth layer and also, the damage on the surface of a epitaxial layer can be avoided and high quality crystals can be obtained.
An apparatus C most suitable with the yo-yo solute feeding method is shown in FIG. 4 in which a source crystal holder 21 for retaining a source crystal 23 is disposed closely on the bottom of a crucible body 20 and a substrate holder 22 for retaining a substrate 24 for crystal growth is detachably mounted above and at a distance from the source crystal holder 21. Also, a sealing liquid 27 of e.g. B 2 O 3 is provided over thesubstrate holder 22 for trapping a solution 40 between the upper and lower holders 22 and 21.
For epitaxial growth with the apparatus C, the supply of the solution 40 follows the placement of the source crystal 23 on the source crystal holder 21 and the substrate holder 22 is mounted to the upper region of the body 20 so that the substrate 24 comes into contact with the upper surface of the solution 40. Then, the sealing liquid 27 is supplied onto the substrate holder 22. As the source crystal 23 is released into the solution 40 by means of the yo-yo solute feeding method or a procedure of periodical increase and decrease of the temperature, a desired epitaxial layer is grown on the upper substrate 24. After the growth of the epitaxial layer, the substrate holder 22 is removed out from the body 20.
An apparatus D shown in FIG. 5 is a modification of the apparatus C in FIG.4 and associated with the yo-yo solute feeding method, in which a substrateholder is arranged for vertical sliding movement like the same of the apparatus B shown in FIG. 3. More specifically, the substrate holder 62 isprovided for sliding movement in a crucible body 60 and has a projection 62a arranged in the central region thereof and coupled to a rod 69 for theupward and downward movement. Like the apparatus B, the apparatus D is placed on a base 92 in a reactor 91 which is encircled by an electric furnace 93.
The epitaxial growth with the apparatus D is similar to that with the apparatus C. It is understood that like the apparatus B, the actuation of the rod 69 involves the engagement and disengagement of the substrate 64 with and from the solution 80 during a step of liquid phase epitaxy by theyo-yo solute feeding method.
EXAMPLES 1 TO 9 AND COMPARISONS 1 AND 2
Examples of the present invention will be described for clarifying how little the dispersion of diffusive elements is involved with the improved inorganic components of the present invention.
The graphite crucibles were employed as porous inorganic articles, and a test for examining the dispersion of diffusive elements was conducted using those processed with filling with an inorganic material (Examples 1 to 3); those further coated with amorphous carbon after the filling process (Examples 4 to 6); those coated with diamond after the filling process (Examples 7 to 9); one without any process done (Comparison 1), and a ceramic crucible (of Al 2 O 3 ) not processed (Comparison 2) by the following test method, the results of which are summarized in Table1. The crucibles employed had the structure shown in FIG. 2 and were of thesame size and shape.
Test Procedure
In the Examples and Comparisons, the solution for epitaxial growth employs InP and is supplied to each crucible at equal concentration and amount, and the upper surface thereof is sealed in with a sealing liquid of B 2 O 3 . Then, the InP solution is maintained at 900° C. for 9 hours and the dispersion of P which is a diffusive element containedin the solution is calculated from the following formula.
The dispersion is expressed by a percentage of the decreased weight of P inthe InP solution (weight of dispersed P) after 9 hours of keeping, to the original weight of P in the solution before the keeping. The vapor pressure of P is 0.023 atm while the solution is maintained at 900°C. ##EQU1##
TABLE 1______________________________________ thickness of thickness of percent- inorganic amorphous diamond age of material carbon layer layer disper- to be filled μm μm sion (%)______________________________________Ex. 1 B.sub.2 O.sub.3 -- -- 9Ex. 2 Bi.sub.2 O.sub.3 -- -- 12Ex. 3 Sb.sub.2 O.sub.3 -- -- 12Ex. 4 B.sub.2 O.sub.3 10 -- 2Ex. 5 Bi.sub.2 O.sub.3 10 -- 3.5Ex. 6 Sb.sub.2 O.sub.3 10 -- 4Ex. 7 B.sub.2 O.sub.3 -- 10 1.5Ex. 8 Bi.sub.2 O.sub.3 -- 10 3.5Ex. 9 Sb.sub.2 O.sub.3 -- 10 3.5Com. Ex. 1 -- -- -- 27Com. Ex. 2 -- -- -- 30______________________________________ | An inorganic article used as a container for holding a solution for crystal growth according to the present invention is provided by filling the pores of substrate having a porous inorganic structure with an inorganic material which has a melting point of 400° to 900° C. A liquid-phase epitaxy apparatus according to the present invention is comprised of a crucible made of the inorganic article or from a material selected from P-BN, quartz and sapphire and has an arrangement with less sliding contact. Thus, the dispersion of diffusive elements contained in a solution during the epitaxial growth is prevented. Accordingly, both the article and the apparatus of the present invention permit growth of crystals having high quality and less structural defects, thus contributing to the production of a semiconductor device made of materials having high vapor pressure. | 2 |
Related to the present patent application is patent application Ser. No. 11/496,191 of Jul. 31, 2006.
TECHNICAL FIELD
The invention concerns power management and image enhancement in visual display devices and, more particularly, in liquid-crystal display devices.
BACKGROUND OF THE INVENTION
Visual display devices are ubiquitous in battery-powered portable electronic devices such as notebook computers and mobile, hand-held telephones where, typically, they are the largest consumers of battery power. For example, in mobile devices equipped with thin-film transistor (TFT) liquid-crystal displays (LCD) utilizing backlight illumination, the LCD panel consumes more than 30% of the device power and the backlight typically consumes 75% of the LCD power. Thus, for conserving battery power, there is primary interest in minimizing the power consumption of the display device.
An LCD screen typically includes an array of liquid-crystal pixels arranged as a plurality of rows each having a plurality of pixels, arranged in columns, with each pixel capable of displaying any one of 256 luminance values of a gray scale and the corresponding chrominance values. Each pixel has its own liquid crystal cell, a dedicated thin-film transistor, and a dedicated capacitor. The electrical field of the capacitor controls the orientation of the liquid crystals within the cell, determining the optical transmissivity of the cell and thus its luminance when lit by a backlight. The capacitor is charged and discharged via its transistor. Device activation typically is row-by-row, so that, at any one time, all column lines are connected to a single row.
For saving power in an LCD device, dynamic backlight control can be used, involving dynamic scaling down and up of the backlight brightness while the device is being used, e.g. in playing back a movie. Moreover, it is beneficial to correspondingly transform an image/pattern to be displayed by transforming the pixel luminance values.
SUMMARY OF THE INVENTION
When the display backlight is set at a specific brightness value, a preferred transformation, (1), of the pixel values can be determined for minimizing perceived image distortion between the original untransformed image at maximum backlight and the transformed image under the specific backlight condition. Furthermore, a preferred transformation, (2), of the pixel values can be determined for minimizing power consumption while meeting an image-quality requirement. A preferred transformation can maximize the luminance of a given pattern and provide optimal contrast by assigning each pixel a value from a given dynamic range of pixel values based on the value of the probability density of the pixel luminance values for the given pattern. Preferably, in effecting a transformation, certain display attributes are taken into account for imposing constraints on transform parameters.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a graph showing an exemplary pixel value distribution along a line of 256 pixel values as may arise for a particular given pattern, and further showing the graphs of the identity transform and of an illustrative multi-stage transform.
FIG. 2 is a graph showing the pixel value distribution of FIG. 1 approximated by a step function, and further showing how the transform slopes are computed.
FIG. 3 is a graph showing a multi-stage transform obtained for the step function of FIG. 2 .
FIG. 4 is a representation of an exemplary procedure for transforming the given pixel values using the pixel value distribution of the given pattern in accordance with a preferred embodiment of the invention.
FIG. 5 is a representation of a further exemplary procedure for transforming the given pixel values using the pixel value distribution of the given pattern, representing a further preferred embodiment of the invention.
FIG. 6 is a block schematic of an exemplary embodiment of the technique.
DETAILED DESCRIPTION
Transform Shape
For a transformation technique, FIG. 1 shows given or input pixel luminance values on the x-axis, output pixel values on the y-axis, and a pictorial representation of a distribution of the pixel values. The straight line from ( 0 , 0 ) to ( 255 , 255 ) represents the identity transform which saves no power and causes no distortion. For backlight control, a transform is desired so that, after scaling the backlight, the maximum perceived luminance value is u<255 at x=255. Then, assuming that the perceived luminance of the pixel is the product of the backlight value and the transformed pixel value, we can scale the backlight by a factor of u/255, saving power.
FIG. 1 also shows a generic multi-stage transform with 4 stages as an example. More generally, on judicious choice of the number of stages/segments and their slope, any desired transformation can be effected. Our invention includes techniques for advantageously determining the number of stages and their slopes.
Constraints On Transform Shape
A preferred transform will meet certain constraints for preventing undesirable effects. For example, if at any stage the slope of the transform were 0, then all the pixel values in that range would get compressed to a single value, resulting in total loss of contrast there. This is the case for certain transforms previously known in the art which clip the high pixel values to a threshold value, resulting in washout of bright pixels in the image. For example, washout will impair images of bulbs and lights due to loss of contrast in the region of the light. Conversely, if a slope is too large, pixel values that are close to each other are dramatically separated in the pixel-value space, causing a distorted rendition as compared with the original image. For example, where a given pixel value distribution has a peak, a swath of pixels have very similar luminance, e.g. in the court of a basketball scene. If the transform then has a high slope for these pixel values, the transformed court will have dramatically varying luminance, and the image will appear distorted.
In addressing such concerns, a preferred technique imposes two constraints on the slope, m, of the transform in any stage:
m≦s max ,
m≧s min , (1)
where s max and s min are determined from a target backlight scaling factor, u/255. Then
s max =255 /u
s min =s× 255 /u
where s is a suitably chosen parameter.
With these constraints, our preferred multistage transform can give good power savings through dynamic backlight control, maintaining brightness, maintaining contrast where necessary, avoiding contrast distortion in important regions, and minimizing washout effect as compared with known transforms.
Estimation of Multistage Transform
For the present description of a preferred technique for estimating a desired multi-stage transform we assume that u is given, i.e. that we know the required backlight scaling factor, and hence the power savings. The technique aims at finding a transform that minimizes distortion while achieving power savings determined by u. A basic exemplary procedure can be described as follows:
(a) In regions where the histogram value is high, i.e., where there are several pixels with that range of values, we maintain the original contrast by using as large a slope value as possible.
(b) In regions where the histogram value is low, i.e., where there are few pixels with values in that range, we use a lesser slope. Contrast is reduced in these regions, but because it affects only a few pixels the reduction is not perceived as much.
We start by dividing the x-axis into B bins, where B can be between 0 and 255. A typical value of B may be between 5 and 30. Then we integrate the original histogram within these bins to get a piecewise uniform density function as shown in FIG. 2 . U(i) denotes the value of the uniform density in bin i.
FIG. 2 also shows the uniform density over the entire dynamic range for comparison. The value of this density is denoted as U. If U(i)>U, then the number of pixels in bin i is greater than average, suggesting that we should maintain the original contrast by using an appropriate slope. If U(i)<U, then a less-than-average number of pixels is indicated in bin i, and so we can afford to lose some contrast by using a lesser slope. For example, as shown in FIG. 2 , a practicable slope can be chosen as the one that transforms the uniform density with the value U(i) in bin i to another uniform density with the value U. This slope is given by
s
(
i
)
=
U
(
i
)
U
(
2
)
On taking account of the constraints given by Equation 1, we obtain the following for determining the slope for bin i:
If s ( i )> s max , then s ( i )= s max
If s ( i )< s min , then s ( i )= s min
FIG. 3 shows what the transform can look like after this step. At this point, the transform does not necessarily meet the desired maximum perceived luminance value, u. Using the target backlight scaling factor, u/255, the maximum desired transformed luminance can be computed as
y f =min (255, x f ×255/ u )
where x f is the maximum input luminance for the frame.
Typically, x f >u, thus typically y f =255. FIG. 3 shows this case; y f =255 is the maximum transformed luminance, allowing a scaling of the backlight by a factor of u/255 to result in a maximum displayed brightness of u. FIG. 3 also shows u, the value the maximum perceived luminance. We are now interested in modifying the computed transform so that it has a maximum value=y f . In FIG. 3 , y f is more than the maximum value given by the current transform, t(255), so that we can scale up the transform by an appropriate factor. If y f were less than t(255), then we would scale down the transform. In either case we honor the constraints given by Equation 1.
FIG. 4 shows an exemplary algorithm, designated as MULTISTAGE, for determining the transform t(p), 0≦p<256. It can be used for task (1) as described in the Summary above.
For task (2) we further seek to meet a prescribed maximum perceived brightness after backlight scaling. FIG. 5 shows an exemplary algorithm, there designated as SCALING, which can be used for task (2). On combining procedures MULTISTAGE and SCALING, both tasks can be performed simultaneously. We note a number of typical applications of the two algorithms individually and in combination as follows:
1. Apply MULTISTAGE alone. Use the maximum value, t(255), to determine the backlight scaling factor, t(255)/255. This seeks to give the best possible image without trying to meet any particular power saving goal.
2. Apply MULTISTAGE. Determine the backlight scale factor based on the desired backlight setting, u. The scale factor is given by u/255. Then apply SCALING. This yields an optimal video or image and also meets the desired power saving goal.
3. Apply a transform with a fixed slope from 0 up to a certain threshold pixel value. Use MULTISTAGE after this threshold value. This seeks to maintain maximum brightness, while still achieving contrast at the high pixel values.
4. Proceed per Application 3 above, and then apply SCALING as in Application 2.
5. Proceed per Application 4 above, but, when applying SCALING, scale the fixed-slope transform only if the minimum slope constraints cannot be met.
6. When used for video, apply a low-pass filter in time to smooth the transform determined for each frame of a scene by any of Applications 1-5 above. This minimizes flicker as may result from very fast transform changes frame to frame.
7. Apply a high-pass filter to sharpen the edges of the video processed by any of applications 1 to 6 described above.
8. By scaling of chrominance pixels, apply a color boost to the chrominance values for improving the color combination of the processed image. For example, in a preferred embodiment in the YUV space, the U and V components each are scaled up by a respective fixed factor. Alternatively, chrominance scaling can involve a generic functional transform of the luminance component.
Interaction With Environment
For an over-all view of a typical implementation of our technique, FIG. 6 shows different types of input 1 to a processor 2 for generating processed video frame output 3 as well as a backlight value 4 for display of video frame output 3 on an end client display device 5 . As illustrated, for example, input 1 can include any/all of: values and statistics of pixels of an input video frame, values and statistics of a past video frame in a sequence of video frames, LCD panel characteristics of the display device 5 , ambient light conditions of the environment in which the input video frame was generated, and user input. Input data are used by processor 2 in determining transform parameters, determining a backlight value, and transforming pixel values. At the display device 5 , the transformed pixel values can be displayed against a backlight as determined by processor 2 , or against some other supplied background. For display, a video/image may be targeted for either or a combination of (i) least power consumption on the display device 5 and (ii) best possible enhancement as compared with the input.
Techniques of the invention can be applied for static backlight setting of an individual display, or dynamically in a scenario where the backlight can be changed from frame to frame of a video sequence. In either case, in processing a frame, the processor 2 can make reference to at least one previously processed frame. A previous frame can also be used for smoothing, e.g. with a suitable small portion α of the pixel values of a previous frame added to a portion (1−α) of the current frame of a scene.
Technological Benefits And Uses
Techniques of the invention can generate high-quality video, still images, graphics, and screen shots of other multimedia applications such as Microsoft Power Point and Word applications, all at minimized display backlight power or at any specific display backlight power. Furthermore, the techniques can be useful for enhancing a display even where there may be little or no concern with backlight power. Our techniques can be implemented for power management and/or image enhancement in notebook-PC's, media players such as DVD playback devices, handheld consumer electronic devices, portable media players, personal digital assistant (PDA) devices, LCD TV's and mobile phones, for example. | In visual display devices such as LCD devices with backlight illumination, the backlight typically consumes most of device battery power. In the interest of displaying a given pixel pattern at a minimized backlight level, the pattern can be transformed while maintaining image quality, with a transform determined from pixel luminance statistics. Aside from, or in addition to such minimizing, a transform also can be used for image enhancement, for a displayed image better to meet a visual perception quality. In either case, the transform preferably is constrained for enforcing one or several display attributes. | 6 |
BOTANICAL/COMMERCIAL CLASSIFICATION
[0001] Persea americana Mill./Avocado Tree
VARIETAL DENOMINATION
[0002] ‘MERENSKY 1’
SUMMARY OF THE INVENTION
[0003] This invention relates to a new and distinct variety of an avocado tree that is named ‘Merensky 1’.
[0004] In the 1970's and early 1980's widespread outbreaks of Phytophthora cinnamomi root rot (P.c.) had devastating effects on most avocado trees grown at Westfalia Estate. The use of clonal rootstocks (such as ‘Duke 7’, introduced to South Africa in 1978 from California) had not yet made much impact and there were very noticeable tree health differences between individual avocado trees at Wesfalia Estate at that time. Fungicides, effective against P.c. were not available. In this period, i.e. in the late 1970's and early 1980's, a healthy seedling avocado tree, later known as ‘Latas’, was selected at Westfalia Estate where it was growing in waterlogged conditions. Vegetative propagation material was taken from this extraordinarily healthy avocado tree to graft several avocado rootstocks with this material. Merensky Technological Services, a research operation of Hans Merensky Holdings, undertook experimental clonal propagation of this rootstock at the Westfalia nursery. Results obtained from experimental plantings showed the ‘Merensky 1’ variety to be promising in terms of fruit production and resistance to Phytophthora cinnamomi root rot. In the 1980's budwood of the ‘Merensky 1’ variety was made available to the University of California/Riverside—Department of Plant Pathology for academic testing. It was found that the ‘Merensky 1’ variety had an additional beneficial characteristic, namely its salinity tolerance as compared to available commercial avocado rootstocks. This and subsequent asexual propagation confirmed the new variety to be stable and that progeny formed is true to type. Had the variety not been discovered and carefully preserved, it could have been lost to mankind. The ‘Merensky 1’ variety is believed to be well-suited as a rootstock, wherein other commercial varieties are grafted thereon for avocado fruit production. The ‘Merensky 1’ variety can be distinguished from all previously known avocado varieties.
BRIEF DESCRIPTION OF THE PHOTOGRAPHS
[0005] The accompanying photographs show specimens of the tree and plant parts of the new ‘Merensky 1’ variety.
[0006] FIG. 1 illustrates a three-year old topworked tree of the ‘Merensky 1’ variety while growing at Westfalia Estate, South Africa.
[0007] FIG. 2 illustrates typical mature foliage of the ‘Merensky 1’ variety, with dimensions in centimeters and inches shown below.
[0008] FIG. 3 illustrates typical flush foliage of the ‘Merensky 1’ variety with dimensions in centimeters shown on the right.
[0009] FIG. 4 illustrates typical inflorescence of the ‘Merensky 1’ variety with dimensions in centimeters shown on the right.
[0010] FIG. 5 illustrates a typical external view of the fruit of the ‘Merensky 1’ variety, with dimensions in centimeters shown below; and
[0011] FIG. 6 illustrates typical internal views of the fruit of the ‘Merensky 1’ variety, with and without the seed, and dimensions in centimeters shown below.
DETAILED DESCRIPTION
[0012] In those instances where precise color assessment can be made, references are to The Royal Horticultural Society (R.H.S.) Color Chart. In other instances, generally, color terms are used in accordance with an ordinary dictionary significance. The instant cultivar ‘Merensky 1’ is described as a plant as a whole in the following description, with the exception as a rootstock for a specific scion when reference is made to root rot resistance and salinity tolerance. The following description is taken from a three-year old topworked tree located at Westfalia Estate, Waterval section. Reference to other varieties, and particularly the ‘Merensky 2’ (U.S. Plant Pat. No. 15,309 P3) is for comparative purposes of a topworked tree of approximately the same age.
Cultural conditions:
[0014] Westfalia Estate, Waterval section, is situated in north-eastern South Africa (latitude 23.45 S, longitude 30.05 E, altitude 750 m above sea level). The soil type is a fine-loamy, mixed paleudult (USDA, 1975. Soil Taxonomy, Soil Conservation Service, Agriculture Handbook No. 436, Washington) with a clay content of 40%. Soil analysis prior to planting indicated a need for phosphate and pH adjustment. Superphosphate was applied to address the phosphate needs and the low soil pH (5.6) was amended to pH 6.5 by applying dolomitic lime. Nutrition requirements are based on annual leaf analyses and fertilizers spread under the tree by hand. There is a deficiency of the trace elements zinc and boron which are supplemented annually. Soil erosion is prevented by planting an annual legume cover crop. Soil moisture is monitored by means of tensiometers and irrigation is applied by micro-sprinklers aimed to wet 100% of soil in the drip zone. Climatic data: Long term average monthly maximum (MAXT)/minimum (MINT) temperatures and monthly rainfall for Westfalia Estate, Waterval section:
JAN FEB MAR APR MAY JUN JUL MAXT 27.8 28.1 27.2 25.7 23.9 21.6 22.3 (° C.) MINT 17.2 17.7 16.7 13.9 9.8 5.7 5.8 (° C.) RAIN 149.3 245.4 153.8 107.1 28.5 30.9 5.0 (mm) AUG SEP OCT NOV DEC YEAR MAXT 23.4 24.3 25.4 26.5 26.9 25.3 (° C.) MINT 7.6 10.8 13.0 14.7 16.7 12.5 (° C.) RAIN 21.8 62.9 107.5 106.5 161.3 1180 (mm)
Tree: Growth habit — Spreading.
[0016] Vigor.— No data is available to quantify the vigor of the ungrafted ‘Merensky 1’ tree. However, data on the vigor of ‘Hass’ grafted onto the rootstock ‘Merensky 1’, as determined by trunk circumference measurement in Years 2- 6 after planting in an orchard with high Phytophthora cinnamomi pressure at Westfalia Estate, South Africa is provided below.
Trunk circumference (cm) Rootstock Year 2 Year 3 Year 4 Year 5 Year 6 ‘Merensky 1’ 20.4 25.9 29.8 32.3 37.3 ‘Merensky 2’ 18.1 23.6 27.5 30.2 34.9 Size.— Medium. The typical tree size of a three-year old topworked ‘Merensky 1’ is 3.8 meters in height and 4.1 meters in width. By comparison, the dimensions of a three-year old topworked ‘Merensky 2’ tree is 4.0 meters in height and 3.6 meters in width. Branch:
Color.— the color of the one-year old branch is green (RHS 147B). Smoothness.— the smoothness of the bark of a one-year old branch is smooth. Lenticels.— the lenticels of a one-year old branch are inconspicuous.
Main stem:
Color.— grey brown (RHS 199B and N199B). Texture of bark.— corky.
Young shoot (Flush):
Intensity of anthocyanin coloration.— weak. By comparison, it is medium in ‘Merensky 2’. Color.— greyed-orange (RHS 176A). Conspicuousness of lenticels.— medium. Color of lenticels.— purple (RHS 187C). Size of lenticels.— 1.0 mm long. Concentration of lenticels.— +/− 30 lenticels per square cm. Color of upper side.— orange-brown (RHS 172A). Glossiness of upper side.— medium. Color of lower surface.— greyed-orange (RHS 174A).
Mature leaf:
Length.— 18.4 cm. By comparison 17 cm for ‘Merensky 2’. Width. 13 8.6 cm. By comparison 7.0 cm for ‘Merensky 2’. Ratio length/width.— 2.1. By comparison 2.4 for ‘Merensky 2’. Shape.— lanceolate to elliptic. Color of upper side.— dark green (RHS 147A). Color of lower side.— medium green (RHS N138B). By comparison ‘Merensky 2’ is medium green (RHS N138C). Glossiness of upper side.— medium. Prominence of veins on lower side.— prominent and in relief. Color of veins.— yellow-green (RHS N144A). General shape and cross - section.— flat. Reflexing of apex.— absent. Color of petiole.— yellow-green (RHS 145A). Anise aroma.— absent. In contrast in ‘Merensky 2’, it is present.
Flower:
Bud size.— approximately 6 mm in length and approximately 4 mm in diameter. Bud shape.— ovoid. Bud color.— commonly near yellow-green group (RHS 149D). Opening.— belongs to Group “B”; female opening (i.e. with mature pistil) occurs in the afternoon, the flower closes over night, and male opening (i.e. with mature stamens) occurs the next morning; the flower's opening cycle lasts 20-24 hours. The “B” flower type is the compliment of “A” (‘Hass’). Commonly avocados of the “B”-type are used for enhancing pollination of ‘Hass’. Petals.— Borne in two whorls of three perianth lobes. The petals possess entire margins and petal coloration is near yellow-green (RHS 145D). Stamen.— There commonly are nine fertile stamens with each having two basal orange nectar glands and three staminodia. The anthers are tetrathecal. Pistil.— The single pistil with a slender style and small stigmatic surface has one carpel with one ovule. The ovary is superior. Pedicel.— Commonly approximately 7 mm in length and approximately 1.8 mm in diameter. The coloration is near yellow-green (RHS 145C). Number of flowers on inflorescence.— There are approximately 90-180 flowers per inflorescence. In contrast, ‘Merensky 2’ has approximately 110-170 flowers per inflorescence. Fragrance.— absent. Bloom.— Bloom period at Westfalia Estate Waterval section varies with temperatures. However the ‘Merensky 1’ variety has been found to bloom from 1 st August through 10 th October. In contrast, the ‘Merensky 2’ variety has been found to bloom from July 3 rd through September 25 th .
Fruit:
Length.— 11.2 cm. Width.— 7.0 cm. Ratio length/width.— 1.6. Shape.— obovate. Color of skin ( when ripe ).—light green (RHS 144A). In contrast, ‘Merensky 2’, very dark green (RHS 137A). Texture of skin.— rough, lenticels bumpy. In contrast, ‘Merensky 2’ very smooth. Presence of longitudinal ridges.— absent. In contrast, ‘Merensky 2’, one strong, long longitudinal ridge. Thickness of skin.— medium to thick. In contrast, ‘Merensky 2’ is very thin and membranous. Adherence of skin to flesh.— weak. In contrast, ‘Merensky 2’ strong. Main color of flesh.— light yellow (RHS 154D). Color of flesh next to skin.— yellow green (RHS 144A). Width of more intensely colored area next to skin.— 3.0 mm. Conspicuousness of fibers in flesh.— conspicuous.
Seed:
Length.— 5.1 cm. In contrast ‘Merensky 2’, 4.8 cm. Width.— 4.5 cm. In contrast ‘Merensky 2’, 4.2 cm. Shape.— in longitudinal section — base flattened, apex rounded. In contrast, ‘Merensky 2’, ovate. Color of seed coat ( fresh ).—orange brown (RHS 165A).
Time of harvesting: March (in South Africa). Resistance to pests: Strong resistance to Phytophthora cinnamomi. Tolerance to salinity: Has shown higher salinity tolerance (significantly lower concentrations of chloride and sodium in leaves of the ‘Hass’ scion grafted onto ‘Merensky 1’) in a field trial than presently used avocado rootstocks. Market use: The fruit of the present variety is not in condition for market use, but rather the variety is used as a rootstock onto which commercial varieties, such as ‘Hass’ are grafted. | A new and distinct variety of Persea americana tree having strong resistance to Phytophthora cinnamomi and tolerance to salinity, and used as a rootstock. | 0 |
FIELD OF THE INVENTION
[0001] The invention relates generally to electronic tags and, more specifically, to RFID electronic tags incorporated into a finished product such as a tire.
BACKGROUND OF THE INVENTION
[0002] RFID electronic tags are incorporated into a variety of finished articles or products such as tires. Such tags include an electronic device for storing data such as a product identification number. The data stored within tag memory is transmitted upon receipt of an interrogation signal from the tag to a remote reader during the product life cycle to provide useful information concerning the product.
SUMMARY OF THE INVENTION
[0003] In an aspect of the invention, a product and electronic tag assembly are provided including a rubber-based article portion. The electronic device and antenna attach to or embed withinthe article portion. The antenna is constructed to be flexible and at least partially composed of a flexible conductive material such as conductive rubber. The flexible antenna conductive material is selected to provide material composition properties substantially equivalent to the article portion, whereby rendering the antenna transparent and mechanically compatible for incorporation into the article portion.
[0004] According to another aspect, the flexible antenna is of a dipole configuration including first and second antenna arms composed of conductive rubber and connected to respective contacts of the electronic device. The flexible antenna arms and the electronic device may be wholly or partially embedded within the article portion or attached thereto.
[0005] In yet a further aspect, the electronic device includes a circuit module and a separator component composed of non-conductive material encasing the circuit module and separating the antenna arms. The antenna arms are secured to the article portion whereby at least a surface portion of the antenna arms faces outwardly and exposed from the article portion in an exposed relationship to an ambient adjacent air mass such as, but not limited to, the air within a tire cavity. The antenna arms may thus be configured and positioned to change transmission characteristics responsive to a change in pressure exerted on the antenna arms by surround article portion material.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] The invention will be described by way of example and with reference to the accompanying drawings in which:
[0007] FIG. 1 is a perspective view of a RFID tag representative of the prior art;
[0008] FIG. 2 is a perspective view of a RFID tag electronic device pursuant to the invention;
[0009] FIG. 3A is a longitudinal sectional view of an RFID tag embodied pursuant to the invention with the intermediary non-conductive separator component removed for the purpose of illustration;
[0010] FIG. 3B is a longitudinal sectional view of the RFID tag with the separator component in place;
[0011] FIG. 5 is a perspective view of an alternatively configured electronic device in which the integrated circuit chip and contact array comprising the electronic device is not encased within a casing;
[0012] FIG. 6 is a longitudinal sectional view of the alternative tag configuration showing encasement of inward ends of the antenna arms by a separator component.
[0013] FIG. 7 is a block level diagram of the procedure for configuring and utilizing the tag as a pressure sensor device.
DETAILED DESCRIPTION OF THE INVENTION
[0014] Referring first to FIG. 1 , a conventional RFID tag 10 is shown to include a substrate 12 supporting an IC (integrated circuit) package 13 having edge contact arrays 16 , 18 . A pair of rigid metallic conductive coiled antenna arms 20 , 22 are electrically coupled to respective contact arrays 16 , 18 of the IC package 14 . The IC package includes an IC chip (not shown) of conventional construction for performing data memory and data transmitting functions. The contacts 16 , 18 are generally of serpentine configuration extending from the IC chip and bending downward to remote ends supported by the substrate 12 . It is to those ends that the coil antenna arms 20 , 22 are coupled by soldering or other known techniques.
[0015] The dipole antenna constituted by the coils 20 , 22 communicate data from the IC package 14 to an external reader. The tag 10 may be incorporated into sundry articles or products by embedding the tag 10 within the article or affixing the tag to the article by adhesive or other known techniques. Coupling the tag 10 with an article or product allows information such as product identification data stored within the IC package to be accessed throughout the life cycle of the product.
[0016] In some end use applications, the product is subjected to rigorous stresses and strains during normal use. Such forces may cause the antenna arms 20 , 22 to separate from the CI contacts 16 , 18 and cause a malfunction. Moreover, the material composition of the metallic coil antenna arms 20 , 22 , the substrate 12 , and the IC package 14 may be dissimilar to the material composition of the host article into which the tag is incorporated. In such an event, the tag is considered “non-transparent” and bonding the tag to a portion of the article or product may become problematic. Failure of the bond may cause the entire tag to become separated from the article or product during use.
[0017] FIG. 2 shows one IC package 24 configured pursuant to the invention. The package includes an outer casing 26 enclosing an IC chip (not shown) from which arrays of contact arms 28 , 30 extend in coplanar linear form. The arrays of contacts 28 , 30 extend through opposite sides of the casing 26 as shown. Each of the contact arms 28 , 30 are elongate and are preferably, although not necessarily, of a straight, non-serpentine configuration, unlike the contacts 16 , 18 of the device 14 shown in FIG. 1 . As used herein, “electronic device” is used interchangeably with “IC package” and refers to the IC circuitry and contacts used in the performance of tag functions such as identification data storage and transmission. The electronic device may include an outer casing 26 as shown in FIG. 2 or may be configured without a casing as shown in FIG. 4 as will be explained.
[0018] With reference to FIG. 3A , the subject tag 32 is shown. IC package or device 24 is positioned in line with a pair of antenna arms 34 , 36 . The antenna arms 34 . 36 are composed of a conductive rubber compound or matrix from commercially available solid or liquid conductive rubber products such as, but not limited to, Zoflex (manufactured and sold by XILOR Inc., and located in Knoxville, Tennessee. The antenna arms 34 , 36 are connected to the RFID electronics at respective arrays of contacts. 28 , 30 . Connection is established by encasing the contacts 28 , 30 within inward ends 38 , 40 of the arms 34 , 36 , respectively. The arms 34 , 36 are of flexible conductive rubber construction having a thickness or width D at inward ends 38 , 40 sufficient to encase the contacts 28 , 30 and to overlap respective opposite ends of the electronic device or IC package 24 . That is, the depth, width D, is wider than the IC package 24 whereby allowing the antenna arm inward ends 38 , 40 to extend over opposite sides and edges of the IC package 24 as seen from FIG. 3A .
[0019] FIG. 3B shows the placement of a separator component 42 about the IC package 24 . The component 42 encases the IC package 24 and is composed of non-conductive material such as a non-conductive rubber. The component 42 thus electrically separates the antenna arms 34 , 36 and further serves to protect the IC package 24 . Preferably, although not necessarily, ends 44 , 46 of the separator component 42 will overlap the ends 38 , 40 of the arms 34 , 36 , thus creating a complete rubber-based casing of the entire tag assembly. That is, the entire tag 32 is sheathed in a rubber base that will be transparent when embedded into an article or product such as a tire that is composed primarily of rubber. The RFID tag 32 thereby lends itself to a low cost method of production such as an extrusion process in which the conductive arm 34 , IC device 24 , non-conductive separator component 42 , and conductive arm 36 are sequentially extruded into a finished tag. The resultant tag will be flexible and bond better and more easily into a rubber product such as a tire. Moreover, because the components are of rubber materials, the tag is more non-obtrusive within a tire portion such as a wall, making the bonding of the tag to the tire stronger and less prone to failure. The risk of tag separation from the tire is thereby minimized.
[0020] FIGS. 3A and 3B show a tag embodiment in which the electronics is encased. FIGS. 4 and 5 show an alternative tag embodiment 48 that eliminates the encasement package of the electronics and affixes flexible conductive rubber-based antenna arms 56 , 58 directly to edge contacts 52 , 54 of an integrated circuit 50 . The IC 50 has arrays of contacts 52 , 54 along opposite edges. The antenna arms 56 , 58 composed as described above from flexible conductive rubber. Inward ends 60 , 62 of the arms 56 , 58 affix over the edges of the IC and thereby establish electrical contact. The diameter or thickness of the arms 56 , 58 is greater than the thickness of the IC 50 . A separator 64 , as shown by FIG. 5 , encases the IC 50 and is dimensioned to overlap the inward ends 60 , 62 of the arms 56 , 58 . The separator component 64 is formed of non-conductive material such as rubber. The resulting tag shown in FIG. 5 is thus completely encased by a material (rubber) compatible with and transparent to the material of a host rubber article such as a tire. The IC 50 is further protected by the flexible external sheath created by the arms 56 , 58 and the separator component 64 .
[0021] The tag 48 can be inserted in its entirety within a wall of an article or product such as a tire sidewall. The RFID tag becomes transparent when embedded into the tires because tires are likewise composed primarily of rubber having generally the same mechanical and material properties as the tag antenna arms 56 , 58 . As a result, performance of the tire is not degraded by the presence of the tag 48 and a bonding of the tag within a tire sidewall is less likely to fail over time from tire use. Compatibility is used herein to mean materials having like mechanical and material properties. Compatibility between the tag 48 composition and that of the host tire product portion into which the tag is embedded thus creates a desired transparency between the tag and the tire.
[0022] The tag 48 may be completely embedded within a wall of the tire; partially embedded; or externally affixed by adhesive or other means. When completely embedded, the flexibility of the tag will complement the flexibility the surrounding tire wall (i.e. become transparent). If partially embedded, a portion of the tag 48 will remain exposed. If affixed by adhesive, the tag 48 will be exposed to the ambient air cavity. It is commonplace to internally mount an RFID to either a tire sidewall defining the tire cavity or to an underside of the tire tread tire portion defining the cavity. So positioned, the tag 48 is proximate to the tire cavity that becomes pressurized when the tire is mounted to a wheel.
[0023] It is contemplated that the tag, whether in the configuration 32 or 48 , when mounted to tire, will function to transmit product identification data, when subjected to an interrogation signal, to a remote reader by means of the dipole antenna arms 34 , 36 ( FIGS. 3A , 3 B) or 56 , 68 ( FIGS. 4 , 5 ). The use of the RFID tag may be extended if desired for deployment as a low cost, durable and passive (requiring no internal power source) pressure sensor for detecting air pressure within an adjacent pressurized ambient air mass. In a tire, the tag can serve as a pressure sensor for measuring the air pressure within a tire cavity. For use as a pressure sensor in a tire, the tag antenna arms are composed of a flexible, electrically conductive, and pressure sensitive material such as conductive polymers or a pressure sensitive polymer. Such a material is commercially available from XILOR, Inc. The signal strength returned from the RFID tag when it is interrogated will vary based on the surrounding pressure brought to bear on the tag antenna arms because the impedance of the rubber changes with pressure.
[0024] If the RFID tag and its antenna arms are completely embedded within a rubber composed wall of an article or product, the RFID tag by varying signal strength will indicated changes of pressure within that wall bearing upon the tag. In the case of measuring tire cavity air pressure, the tag may be embedded within a wall of the tire defining the tire cavity. Changes in air pressure within the cavity will change compression forces within the tire walls defining the tire and will thereby vary the compressive forces bearing on the antenna arms. The change in compression forces on the tag antenna arms will be reflected in a variance in signal strength, whereby serving to communicate tire cavity air pressure.
[0025] The RFID tag may also be partially embedded within the tire wall such that a portion or the entirety of the antenna arms remain exposed to the ambient air mass within the tire cavity. In this system, changes in tire cavity air pressure will directly impact against the tag antenna arms and change impedance of the rubber therein. The change in signal strength can be detected by an external reader and calculations made to determine the air pressure within the cavity that correlates with the impedance values within the antenna arm rubber. Likewise, the tag may be mounted against the tire sidewall by adhesive agents or the like, and a similar procedure used to measure the signal variation resulting from pressure changes against the tag antenna arms.
[0026] In the aforementioned pressure sensor applications, as seen from the block diagram of FIG. 6 , it is necessary to first study and calculate the conductive rubber within the antenna arms and how the impedance will vary according to pressure on the arms. Once such a study and calculations are completed, pressure sensor application of the tag within a product and article can be made. An interrogation of the tag from an external signal will result in data transmission from the tag to a reader. The transmission signal can then be analyzed and, from its strength, the impedance of the antenna arms deduced. From the impedance value thus calculated, the pressure against the antenna arms may be determined and a conclusion of air pressure within the tire cavity necessary to produce such a pressure on the arms can be calculated.
[0027] With specific reference to FIG. 6 , the procedure for implementing a pressure sensor tag application is as follows calculate impedance of tag rubber antenna arms; calculate changes in antenna arm impedance resulting from changes in pressure exerted on antenna arms; determine changes in tag transmission signal strength from changes in antenna arm impedance; ilncorporate tag into rubber-based tire wall defining pressurized tire cavity; Interrogate tag to initiate return data signal; measure strength of return data signal; calculate impedance of antenna arms required to result in measured data signal strength; determine pressure exerted on antenna arms required to result in calculated antenna arm impedance; calculate air pressure within the tire cavity required to generate pressure exerted on antenna arms.
[0028] Variations in the present invention are possible in light of the description of it provided herein. While certain representative embodiments and details have been shown for the purpose of illustrating the subject invention, it will be apparent to those skilled in this art that various changes and modifications can be made therein without departing from the scope of the subject invention. It is, therefore, to be understood that changes can be made in the particular embodiments described which will be within the full intended scope of the invention as defined by the following appended claims. | A host article and electronic tag assembly includes an article portion of rubber-based material composition. The electronic device and antenna attach to or are embedded within the article portion. The antenna is constructed to be flexible and at least partially composed of a flexible conductive material such as conductive rubber. The flexible antenna conductive material is selected to provide material composition properties substantially equivalent to the rubber-based article portion, whereby rendering the antenna mechanically compatible for incorporation into the article portion. A change in compression within the rubber-based article portion changes compression forces exerted from the article portion on the antenna arms which, in turn, results in a detectable change in signal strength from the tag. The antenna may further be configured and positioned within the article portion to change transmission characteristics responsive to a change of air pressure in an ambient adjacent air mass within the article, and thereby function as an air pressure sensor. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This applications claims the benefit of PCT/EP 2004/003565, filed Apr. 3, 2004 and claims priority of German Application No. 103 15 131.1 filed on Apr. 3, 2003
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention concerns a headlamp for vehicles with at least one planar luminous panel having a plurality of luminous-element chips, and with an optical element arranged in the beam path of the light beam emitted by the luminous panel.
[0004] 2. Related Art
[0005] From DE 100 09 782 A1 is known a headlamp for vehicles in which a plurality of luminous-element chips are arranged in the form of a matrix. To produce different light functions, a group of different luminous-element chips can be activated, so that a predetermined luminance distribution can be produced in conjunction with an optical element mounted in front of the luminous panel.
[0006] Also from EP 1 270 324 A2 is known a headlamp for vehicles with a plurality of luminous-element chips, different groups of luminous-element chips being activatable to produce different light functions. The plurality of luminous-element chips form a planar luminous panel which emits a light beam in the direction of light emission to an optical element designed as a converging lens. The optical element collects the light beam emitted by the luminous panel according to a predetermined luminance distribution.
[0007] With the known headlamps, the planar luminous panel is formed by a two-dimensional array in which the luminous-element chips are densely packed and regularly assembled.
SUMMARY OF THE INVENTION
[0008] It is the object of the present invention to develop a headlamp for vehicles in such a way that firstly a space-saving and compact structure is ensured and secondly the effectiveness of the headlamp is increased.
[0009] To achieve this object, the invention in combination with the introductory part of patent claim 1 is characterised in that the luminous-element chips of the luminous panel are arranged in a common recess and in that the recess on one side facing in the direction of light emission has an edge in such a way in a spatial arrangement to the luminous-element chips that a predetermined luminance gradient in a luminance distribution of the headlamp is formed in the region of the edges.
[0010] Advantageously, due to a selected edge of a luminous panel which is spatially in relationship to the luminous-element chips, the invention allows the formation of a relatively sharp light/dark boundary in the luminance distribution of the headlamp. The basic concept of the invention is to position a plurality of luminous-element chips in a spatial arrangement to an edge, so that a steep luminance gradient is formed in a luminance distribution along a line perpendicularly to the edge. By this means, in combination with the optical element mounted in front, a light/dark boundary of substantially improved design can be produced.
[0011] According to a preferred embodiment of the invention, the recess is trough-shaped for receiving the luminous-element chips, the edge being formed by the free end of an edge wall extending from a base side of the luminous panel. Advantageously, the recess can serve as a common housing for the plurality of luminous-element chips, wherein, due to selective relative spatial arrangement of some of the luminous-element chips to the edge, the formation of a sharp light/dark boundary is promoted substantially.
[0012] According to a development of the invention, the shape of the recess or the shape of the edge or edge wall of the recess is adapted to the luminance distribution to be produced. The shape of the recess or edge thus marks the luminance distribution, wherein for example by means of an edge provided with a break an asymmetrical luminance distribution can be produced.
[0013] According to a development of the invention, the recess is filled with a light-converting luminescent material, so that the light emitted by the luminous-element chips is converted to white light. Advantageously, the luminescent material is integrated in a cast material, so that in a space-saving manner firstly light conversion and secondly mechanical protective covering of the luminous-element chips are provided.
[0014] According to a development of the invention, a bottom surface of the recess is reflectively coated, so that there is an increase in lighting efficiency and furthermore the steepness of the luminance gradients can be influenced in the desired manner.
[0015] Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
[0017] Practical examples of the invention are described in more detail below with the aid of the drawings. They show:
[0018] FIG. 1 a a schematic perspective view of a first embodiment of the invention,
[0019] FIG. 1 b a light distribution of the headlamp as in FIG. 1 a,
[0020] FIG. 2 a perspective drawing of a luminous plate of the headlamp having the plurality of luminous-element chips as in FIG. 1 a,
[0021] FIG. 3 a section along the line III-III as in FIG. 2 ,
[0022] FIG. 4 a a top view of a luminous panel of the headlamp as in FIG. 1 a or of a luminous plate of the headlamp as in FIG. 2 ,
[0023] FIG. 4 b a luminance distribution of the luminous panel as in FIG. 4 a along the lines a and b,
[0024] FIG. 5 a a schematic perspective view of a headlamp according to a second embodiment,
[0025] FIG. 5 b a light distribution of the headlamp as in FIG. 5 a,
[0026] FIG. 6 a a top view of a luminous panel of the headlamp as in FIG. 5 a,
[0027] FIG. 6 b a luminance distribution of the luminous panel as in FIG. 6 a along the lines a and b,
[0028] FIG. 7 a a schematic perspective view of a headlamp according to a third embodiment,
[0029] FIG. 7 b a light distribution of the luminous panel as in FIG. 7 a along the lines a and b,
[0030] FIG. 8 a a top view of a luminous panel of the headlamp as in FIG. 7 a, and
[0031] FIG. 8 b a luminance distribution of the luminous panel as in FIG. 8 a along the lines a and b.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0032] The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.
[0033] A headlamp for vehicles according to a first embodiment as in FIG. 1 a to FIG. 4 b essentially consists of a luminous plate 1 and an optical element 2 , which are fixed in a conventional manner in a headlamp housing, not shown. Alternatively, several luminous plates 1 which in combination produce a common light distribution may be provided.
[0034] The luminous plate 1 has a triangular luminous panel 3 in which are arranged a plurality of luminous-element chips 4 .
[0035] As can be seen better from FIGS. 2 and 3 , the luminous plate 1 has a recess 5 to the bottom surface 6 of which are attached the luminous-element chips 4 . The recess 5 is designed as a trough, wherein upright edge walls 7 extend from the bottom side 6 at the edge in the direction of a direction of light emission 8 of the luminous panel 3 . The free end of the edge wall 7 forms an edge 9 from which a front side 10 of the luminous plate 1 , which front side 10 defines the recess 5 , extends in a plane. The luminous plate 1 is cuboid.
[0036] The bottom side 6 may be reflectively coated, so that the luminance distribution is improved.
[0037] As is clear from FIG. 1 a, the luminous plate 1 abuts by the front side 10 against a light input surface 11 of the optical element 2 .
[0038] The optical element 2 serves as a light-conducting element and has a convex-shaped light exit surface 12 in the direction of light emission 8 .
[0039] In FIG. 1 b is shown the light distribution of this headlamp, different regions L 1 , L 2 , L 3 of the luminous panel 3 being responsible for different intensities I 1 , I 2 , I 3 of luminance distribution.
[0040] As is particularly clear from FIGS. 4 a and 4 b, the luminous-element chips 4 are also positioned in a triangular arrangement in the recess 5 which is triangular in a top view, the distance from the luminous-element chips 4 facing towards a preferred edge wall 7 ′ of the triangular recess 5 , to the edge wall 7 ′, being small. Preferably, these luminous-element chips 4 abut directly against the corresponding edge wall 7 ′. The gap between the luminous-element chips 4 and the other edge walls 7 ″ is filled by a filler with a light-collecting or light-converting auxiliary material. Preferably, the luminous-element chips 4 are completely covered with a cast material 13 which extends from the bottom side 6 to a plane in which the front side 10 extends. The cast material 13 has in particular a light-converting luminescent material by means of which the blue light emitted by the luminous-element chips 4 is converted to white light by additive colour mixing.
[0041] The luminous-element chips can be designed as volume spots having a size of 1 mm 2 . The luminous-element chips 4 are constructed so as to be able to emit light in a lateral direction, that is, perpendicularly to the main direction of emission. The luminous-element chips 4 are preferably designed as light-emitting diode chips (LED chips).
[0042] As is clear from the luminance distribution L along the lines a and b as in FIG. 4 b, the lateral distance from the luminous-element chips 4 to the respective edge walls 7 , 7 ′, 7 ″ has a substantial effect on the shape of a luminance gradient G. A gradient G′ in the region of the preferred edge wall 7 ′ is relatively large, that is, the luminance distribution has a steep ascent in this region, so that in combination with the optical element 2 a relatively sharp light/dark boundary LDB can be obtained. The other transitions in the regions of the edge wall 7 ″ have a smaller luminance gradient G″.
[0043] According to a second embodiment of a headlamp as in FIGS. 5 a to 6 b, a luminous plate 20 with a rectangular luminous panel 21 is provided. The luminous plate 20 rests in planar fashion on a bottom surface 22 of an optical element 23 . The optical element 23 has an arcuate reflective surface 24 which is formed after the fashion of a hammer-forged surface, so that a luminance distribution as in FIG. 5 b is produced.
[0044] As can be seen from FIGS. 6 a and 6 b, the luminous-element chips 4 lie relatively close to a preferred edge wall 25 ′, so that a relatively large luminance gradient G′ is obtainable. The latter allows the relatively sharp light/dark boundary LDB, the asymmetrical shape of the light/dark boundary LDB (15° ascent) being produced by the bulging shape of the reflective surface 24 of the optical element 23 .
[0045] In FIG. 5 b is shown the intensity peak 12 which is determined in width and shape by the four luminous-element chips 4 . The intensity I 1 at the light/dark boundary LDB is determined by the strong decline in luminance L 1 in the region of the preferred edge wall 25 ′. The distance between the luminous-element chips 4 and the other edge walls 25 ″ is greater, so that the corresponding luminance gradients G″ are made flatter. The distance between the luminous-element chips 4 and the edge walls 25 is a measure of the steepness of the decrease in luminance or the magnitude of the luminance gradient G.
[0046] According to a third embodiment as in FIGS. 7 a to 8 b, a luminous plate 30 with an asymmetrically constructed luminous-panel/recess 31 is provided. The luminous panel and the recess 31 are defined by edge walls 32 in accordance with the preceding examples, a preferred edge wall 32 ′ having a break 33 from which a section of the edge wall 32 ′ extends further at an angle of 50°. The luminous-element chips 4 abut directly by their side walls against the two sections of the edge wall 32 ′ separated by the break 33 , so that a large luminance gradient G′ is formed to form the light/dark boundary LDB.
[0047] As can be seen from FIGS. 7 a and 7 b, an optical element 34 which is designed as a lens and arranged at a distance from the luminous plate 30 is provided. A lower region L 1 of the luminous panel which runs along the preferred edge wall 32 ′ corresponds to an intensity range I 1 of light distribution, at the edge of which runs the light/dark boundary LDB. An upper region L 2 of the luminous panel is projected in a lower intensity range I 2 of light distribution projected on a measuring screen arranged at a standardised distance. The luminous plate 30 is preferably arranged in a focal plane of the lens 34 .
[0048] A common feature of the above practical examples is that most of the recess is filled by the luminous-element chips 4 , but for the formation of a light/dark boundary LDB the distance from groups of luminous-element chips 4 to the edge is relatively small or zero. The different geometries of the luminous panels can be used individually or in combination to generate different light distributions, in particular in each case for the formation of basic light, asymmetrical light or other light configurations. The headlamp formed in this way can, for example, be used to produce a dipped beam, main beam, motorway beam and/or cornering beam function.
[0049] As various modifications could be made to the exemplary embodiments, as described above with reference to the corresponding illustrations, without departing from the scope of the invention, it is intended that all matter contained in the foregoing description and shown in the accompanying drawings shall be interpreted as illustrative rather than limiting. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims appended hereto and their equivalents. | A headlamp for vehicle has at least one planar luminous panel of luminous-element chips, and an optical element arranged in the beam path of the light beam emitted by the luminous panel. The luminous-element chips ( 4 ) of the luminous panel ( 3, 21, 31 ) are arranged in a common recess ( 5 ). The recess ( 5 ) is on the side facing the direction of the light emission. The headlamp has an edge in spatial arrangement to the luminous-element chips such ( 4 ) that a predetermined luminance gradient (G, G′, G″) in a light distribution (L) of the headlamp is formed in the region of the edges ( 9, 25, 32 ). | 5 |
RELATED APPLICATION
This application claims the benefit of U.S. Provisional Application Ser. No. 60/410,496, filed Sep. 13, 2002.
FIELD OF THE INVENTION
This invention relates generally to valves and more particularly to on/off valves, throttling valves and control valves.
DESCRIPTION OF THE RELATED ART
Throttling valves, on/off valves and control valves are used in a wide number of process control system applications to control some parameter of a process fluid. While the process control system uses such a valve to ultimately control the pressure, level, pH or other desired parameter of a fluid, the valve basically controls the rate of fluid flow.
Typically, an on/off valve, throttling valve, or control valve includes a fluid inlet passage coupled through an orifice to a fluid outlet passage and a closure member disposed in the orifice, which controls the amount of fluid flow therethrough. The closure member may include a valve plug having a surface which seats against a seat ring disposed at the orifice. During operation, the control system moves the valve plug towards and away from a surface of the seat ring to provide a desired fluid flow through the orifice and, therefore, the valve.
It is desirable to positively retain valve trim components within a valve body of a control valve to minimize the chance of loose pieces traveling downstream and causing damage to other process equipment such as, for example, compressors, pumps, or turboexpanders. For example, in some control valves, the valve plug may be threadably secured to a valve stem, and prevented from rotating with respect to the valve stem by a locking pin that may be disposed within a bore passing through both the valve plug and the valve stem. The locking pin may be press fit into the bore, or alternatively, a bolt may be used in place of the locking pin that may be threadably received within the bore passing through the valve plug and the valve stem.
In order to prevent the locking pin or locking bolt from exiting the bore, by selecting the appropriate pin material, stem material, and hole size, a tightly fitting pin , such as a groove pin, may be used, to reliably stay in place without positive mechanical restraint. However, the locking pin must be drilled out for removal during valve maintenance. In addition, some valves are configured such that a cage trim, disposed between the valve seat and the valve bonnet, serves to prevent the locking pin or locking bolt from exiting the bore during valve operation. However, if the valve is disassembled by separating the valve bonnet from the valve body, the locking pin or locking bolt may be accessed and removed if desired.
In addition, for some applications, it may not be desirable to utilize a valve cage. For example, if the fluid being controlled is likely to clog the valve cage (such as, for example, a gritty or sticky process fluid), a different configuration for retaining the locking pin or locking bolt without the use of a cage trim, may be desirable.
SUMMARY OF THE DISCLOSURE
A valve trim assembly is provided for a process control valve having a valve body and a bonnet. The valve trim assembly includes a valve plug adapted to move to one of a plurality of operational positions with respect to the valve body. The valve plug includes a plug bore, and a movable valve stem is attached to the valve plug. The movable valve stem includes a stem bore therein that is adapted to substantially align with the plug bore. A locking member is disposed in the stem bore and the plug bore and a retaining member may be attached to the bonnet. The retaining member substantially surrounds the locking member at all operational positions of the valve plug.
BRIEF DESCRIPTION OF THE DRAWINGS
The advantages of the present invention will be apparent upon reading the following description in conjunction with the drawings, in which:
FIG. 1 is a cross-sectional view of a control valve including a mechanically retained locking pin in accordance with the teachings of the present invention; and
FIG. 2 is an enlarged detail view of a portion of the control valve of FIG. 1 .
DETAILED DESCRIPTION
With reference initially to FIG. 1 , a process control valve 20 includes a valve body 22 that includes an outlet passage 24 , an inlet passage 26 , an orifice 27 disposed between the outlet passage 24 and the inlet passage 26 , and a bonnet 28 . (In an alternate example, the inlet passage 26 and the outlet passage 24 may be reversed, such that the fluid inlet passage becomes the fluid outlet passage, and the fluid outlet passage becomes the fluid inlet passage, thereby changing an upward flow valve to a downward flow valve.) An actuator housing 30 is attached to the bonnet 28 .
A valve trim assembly, generally indicated at 31 , includes a valve stem 32 and a valve plug 34 that may be secured to a lower end 36 of the valve stem 32 , as oriented in FIG. 1 . The valve stem 32 may extend through the actuator housing 30 , the bonnet 28 , and partially into the valve body 22 .
The valve plug 34 may be sized and shaped to sealingly engage a valve seat ring 38 disposed within the orifice 27 in the valve body 22 when the process control valve 20 is in a closed configuration. The valve stem 32 may be moved vertically in a known manner with respect to the bonnet 28 , the actuator housing 30 , and the valve body 22 . For example, a diaphragm 40 within the actuator housing 30 may be used to facilitate vertical movement of the valve stem 32 . The diaphragm 40 may be secured to the valve stem 32 using nuts 41 and upper and lower diaphragm washers 43 and 45 , respectively. The actuator housing may be secured to the bonnet 28 using cap screws 47 .
The valve plug 34 may be threadably connected to the lower end 36 of the valve stem 32 , as best seen in FIG. 2. A locking member such as a locking pin 42 may be disposed in a stem bore 44 in the valve stem 32 that is aligned with a corresponding plug bore 46 in the valve plug 34 . The locking pin 42 may be sized such that a first end 48 and a second end 50 of the locking pin 42 are both disposed within the plug bore 46 .
As is generally understood in the art, movement of the diaphragm 40 causes movement of the valve plug 34 to one of a plurality of operational positions with respect to the valve body 22 . Accordingly, by controlling the pressure present in the upper and/or lower chambers of the actuator housing 30 , the position of the valve plug 34 may be controlled. As shown in FIG. 1 , the process control valve 20 may include a preload spring 49 and an adjusting screw 51 for adjusting the amount of force provided by the preload spring 49 . It will be appreciated that other types of actuators in addition to the diaphragm actuator illustrated in FIG. 1 may be used without departing from the present invention.
In order to provide proper sealing, packing 52 may be provided between the valve stem 32 and the bonnet 28 . The bonnet 28 may be secured to the valve body 22 by a hammer nut 54 threadably secured to the valve body 22 . The packing 52 may be secured in place by a packing retainer 56 that may be threadably attached to the bonnet 28 and that may be further secured in place by a lock nut 58 . The lock nut 58 may be configured as described in commonly assigned and co-pending U.S. Provisional Patent Application Ser. No. 60/410,620 entitled, “Retainer Lock Nut for Fluid Pressure Control Device”.
The packing retainer 56 includes a lower portion 60 that extends downwardly, as oriented in FIGS. 1 and 2 . The lower portion 60 may be cylindrically-shaped, and serves as a retaining member that surrounds the locking pin 42 during operation of the process control valve 20 . Specifically, while the valve is in operation, both the first end 48 and the second 50 of the locking pin 42 are prevented from extending beyond the surface of the valve plug 34 by the presence of the lower portion 60 of the packing retainer 56 . The location of the locking pin 42 may be selected such that the valve seat ring 38 does not allow the valve plug 34 to travel downward sufficiently to expose the locking pin 42 below the lower portion 60 of the packing retainer 56 . Thus, over its entire range of travel, between a first or upper travel limit, and a second or lower travel limit, the valve plug 34 will always remain in a position such that the first end 48 and the second end 50 of the locking pin 42 will be constrained by the lower portion 60 of the packing retainer 56 .
During valve maintenance, it may be highly desirable to access the locking pin 42 (for example, in order to replace or refinish the valve plug 34 ) without disassembling the actuator housing 30 or disturbing the position of the adjusting screw 51 . Accordingly, the process control valve 20 may be designed with sufficient stem travel to allow the locking pin 42 to be exposed and not covered by the lower portion 60 of the packing retainer 56 when the process control valve 20 is disassembled by removing the hammer nut 54 from the valve body 22 . The amount of actuator travel may be controlled by the distance between the lower diaphragm washer 45 and the cap screws 47 . The hammer nut 54 has sufficient thread engagement with the valve body 22 to provide a safe, easy way to control the stem position during valve disassembly without disturbing the position of the adjusting screw 51 .
By positively retaining the locking pin 42 by mechanical means, the locking pin material, stem material, and the amount of mechanical interference between the locking pin 42 and the bores 44 and 46 in the valve stem 32 and the valve plug 34 , respectively, may be such that the locking pin may be easily removed with a hammer and a punch during valve maintenance procedures. For example, the locking pin material may be UNS S17400 and the stem material may be UNS S20910. Additionally, the amount of mechanical interference in the illustrated embodiment may be defined by a 5/32 inch (0.397 cm) Type E groove pin, per American Society of Mechanical Engineers (ASME) Standard B18.8.2, with corresponding bore diameters 44 and 46 each in a range of from approximately 0.158 inches (0.401 cm) to approximately 0.160 inches (0.406 cm). This condition is sometimes referred to as a “loose” pin connection, and avoids situations in which the locking pin must be drilled out for removal, as may be required if an interference fit is used in the absence of such mechanical restraint.
Since the packing retainer 56 is threaded to the bonnet 28 , the packing retainer 56 will not remain stuck inside the valve body 22 when the bonnet 28 is removed. The alignment and retention of the plug 34 onto the valve stem 32 may be achieved without the need for a cage, which may be advantageous, especially in certain applications, such as, for example, where the process fluid is gritty or sticky and therefore a cage can cause the valve to become clogged or the valve plug 34 to bind.
As configured in accordance with the present disclosure, the disassembly of the process control valve 20 does not require disassembly of the packing 52 . Accordingly, the level of packing stress or preload may be preserved, ensuring that packing sealing performance is consistent with pre-maintenance operation. This configuration simplifies valve maintenance for assemblies that simply have worn or damaged trim and do not require packing adjustment or packing replacement. In addition, by not having to remove the packing or the valve stem, packing damage may be avoided and therefore the need for packing replacement due to damage during valve maintenance may also be avoided. The configuration also has an advantage of avoiding the need to disassemble the actuator housing 30 during valve maintenance, thus maintaining proper spring adjustment.
The foregoing detailed description has been given for clearness of understanding only and no unnecessary limitations should be understood therefrom, as modifications will be obvious to those skilled in the art. For example, the invention is applicable to many types of valves in addition to on/off valves, throttling valves, and control valves, and is also applicable to valves that include a different type of locking member, such as a locking bolt instead of a locking pin for securing the valve stem to the valve plug.
Thus, while the present invention has been described with reference to specific examples, which are intended to be illustrative only and not to be limiting of the invention, it will be apparent to those of ordinary skill in the art that changes, additions or deletions may be made to the disclosed embodiments without departing from the spirit and scope of the invention. | A process control valve includes a valve stem, a valve plug. The valve stem and the valve plug are attached to one another by an arrangement that includes a locking pin that passes through substantially aligned bores in the valve stem and the valve plug. The locking pin is positively retained mechanically and prevented from extending outside of the bores in the valve stem and the valve plug. | 5 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] Reference is made to and priority claimed from U.S. provisional application Ser. No. 61/001,541, filed Nov. 1, 2007, entitled PAINT CAN STAND WITH ADJUSTABLE POLE.
BACKGROUND OF THE INVENTION
[0002] 1. Technical Field
[0003] The present invention relates to a paint can stand for holding paint cans; and more particularly to a paint can stand having a carrying handle and an adjustable pole, which provides height adjustment for various conditions.
[0004] 2. Discussion of Related Art
[0005] Painters frequently use a stand up ladder having a folding tray to support a can of paint while the painter is painting. While this approach may be functional, there is always a chance that the paint can could tip over and spill the contents. In this exemplary situation, the paint can is not secured but rather rests on the top of the tray. Thus if a painter becomes careless or is distracted, there is a possibility of knocking the paint can off the ladder tray and spilling large quantities of paint.
[0006] It would be advantageous to provide the painter with an apparatus for holding the paint can that is not attached to the ladder yet is still adjustable in height, thus the paint can would not tip over if accidentally made unsteady by the painter's movements on the ladder. This problem can be eliminated if the painter uses a separate, adjustable stand capable of holding a gallon paint can, or a smaller paint can. The stand is further advantageous if provided with a handle allowing the painter to relocate the entire unit, i.e. the paint can engaged in paint can stand, simply by grasping and carrying the handle.
SUMMARY OF THE INVENTION
[0007] In accordance with a first broad aspect of the invention, a paint can stand comprises a basket configured for receiving and holding a paint can, an adjustable pole configured for engaging and supporting the basket, and a base configured for detachably receiving and securely holding one end of the adjustable pole so as to provide a foundation for the paint can stand. The adjustable pole has a first and second portion, the first portion having a plurality of aperture and corresponding pegs arranged along its longitudinal axis, each peg being configured to be responsive to a force, for being pushed into a respective aperture when the force is applied, and for being extended outwardly from the respective aperture when the force is not applied; and the second portion having a hole dimensionally sized for receiving and engaging one of the plurality of the pegs when the force is applied then released so as to adjust the paint can stand to a particular height for holding the paint can in the basket. The base has a collar configured to receive the adjustable pole. The first portion, the second portion and the base are detachably coupled together so that the paint can stand can be quickly and easily assembled together for use and disassembled and easily stored when not in use.
[0008] In some embodiments, the basket can have a flexible handle pivotally attached thereto configured for lifting and carrying said paint can stand. In some embodiments, the base is configured in a substantially x-shaped arrangement. In some embodiments, the base is dimensionally sized to extend outwardly beyond an outermost periphery of the basket for increased base of support. In some embodiments, the base comprises a collar configured to removably affix the one end of the second portion of the adjustable pole. In some embodiments, the basket is substantially open and has spaced-apart supportive pieces extending from a supportive base of the basket to a top rim of the basket. In some embodiments, the supportive base of the basket has a substantially x-shaped configuration. In some embodiments, the basket is dimensionally sized to accommodate a gallon-sized paint can. In some embodiments, the handle is substantially arc-shaped and dimensionally sized to be able to freely swing from one side of the paint can stand to another side of the paint can stand while a can of paint is engaged in the paint can stand. In some embodiments, the basket is made of a light band metal. In some embodiments, the adjustable pole is made of aluminum. In some embodiments, the adjustable pole is made of steel. In some embodiments, the collar is removably affixed to the second portion of the adjustable pole using a peg and hole mechanism. In some embodiments, the collar is removably affixed to the second portion of the adjustable pole by screwing the one end of second portion into the collar. In some embodiments, the adjustable pole is extendable from 1 to 3 feet in height. In some embodiments, the adjustable pole is extendable from 3 to 6 feet in height. In some embodiments, the basket and the first pole portion are detachably coupled together, including being respectively configured for screwing together.
[0009] One embodiment is shown and described herein wherein a basket is configured for receiving and holding the paint can; an adjustable pole is configured for engaging and supporting said basket, the adjustable pole having a first and second portion, the first portion having a plurality of aperture and corresponding pegs arranged along its longitudinal axis, each peg being configured to be responsive to a force, for being pushed into a respective aperture when the force is applied, and for being extended outwardly from the respective aperture when the force is not applied, and the second portion having a hole dimensionally sized for receiving and engaging one of the plurality of the pegs when the force is applied then released so as to adjust the paint can stand to a particular height for holding the paint can in the basket; and a base being configured for detachably receiving and securely holding one end of the second portion of said adjustable pole so as to provide a foundation for the paint can stand, such that the first portion, the second portion and the base being detachably coupled together so that the paint can stand can be quickly and easily assembled together for use and disassembled and easily stored when not in use.
[0010] In other embodiments, the basket and the first pole portion may be detachably coupled together, including being respectively configured for screwing together, or being coupled together in a manner similar to the technique for coupling the second portion of the adjustable pole and the base.
[0011] Another embodiment is shown and described herein wherein the paint can stand comprises a basket configured for receiving and holding a paint can; an adjustable pole configured for detachably engaging and supporting said basket, said adjustable pole having first and second pole portions being dimensioned and configured so that one pole portion fits telescopically inside and slides in relation to the other pole portion so as to adjust the length of the adjustable pole and so that the first and second pole portions frictionally engaging with one another so as to remain frictionally locked in an adjusted position; a base configured for detachably coupling and securely holding either the first or second pipe portions so as to provide a foundation for the paint can stand; whereby the basket, the first portion, the second portion and the base all being detachably coupled together so that the paint can stand can be quickly and easily assembled together for use and disassembled and easily stored when not in use.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 shows a side view of the assembled paint can stand.
[0013] FIGS. 2A-2D show the separate elements of the paint can stand of FIG. 1 .
[0014] FIG. 2A shows a top view of the base of the paint can stand of FIG. 1 .
[0015] FIG. 2B shows a side view of the adjustable pole of the paint can, stand of FIG. 1 .
[0016] FIG. 2C shows a top view of the basket of the paint can stand of FIG. 1 .
[0017] FIG. 2D shows a side view of the basket of the paint can stand of FIG. 1 .
[0018] FIG. 3 shows a side view of another embodiment of the assembled paint can stand.
DETAILED DESCRIPTION
[0019] As shown in FIGS. 1 and 2 A- 2 D, the present invention features a paint can stand ( 1 ) having a basket ( 2 ) for engagement with a paint can, the basket ( 2 ) being affixed to an adjustable pole ( 10 ) configured for height adjustment of the stand ( 1 ), and the adjustable pole ( 10 ) further being affixed to a base ( 9 ) for support. The basket ( 2 ) is cylindrical in shape and sufficiently wide and deep to contain a standard paint can, and may be comprised of a light band metal. The scope of the invention is not intended to be limited to the type or kind of material of which the basket is comprised of either now known or later developed in the future.
[0020] Affixed to the basket ( 2 ) is an easy-swing handle ( 3 ) used for carrying the paint can stand ( 1 ). The handle ( 3 ) is semi-circular in shape and is affixed to opposite sides of the basket ( 2 ). The handle ( 3 ) rests alongside the basket ( 2 ) when in the resting position and is in an arced position above the stand when being carried. The handle ( 3 ) is dimensionally sized to be able to make a full arc swing from side to side while a standard gallon-size paint can is situated inside the basket ( 2 ).
[0021] The adjustable pole ( 10 ) comprises two portions, which may be comprised of aluminum or steel. The scope of the invention is not intended to be limited to the type or kind of material from which the adjustable pole is made either now known or later developed in the future. The first portion ( 4 ) is a hollow cylindrical tube affixed at one end to the supportive bottom surface of the basket ( 2 ). Affixed to the first portion ( 4 ) of the adjustable pole ( 10 ) are evenly spaced pegs ( 5 ) for engaging with the second portion ( 6 ) of the adjustable pole ( 10 ). The pegs ( 5 ) may utilize compressive technique configured for allowing the pegs ( 5 ) to be compressed into the inner hollow portion of the tube when a compressing force is applied. Such compressive techniques are known in the art, and the scope of the invention is not intended to be limited to any particular type or kind either now known or later developed in the future. The second portion ( 6 ) is a hollow cylindrical tube having a slightly larger diameter than the first portion ( 4 ) such that the first portion ( 4 ) can be slidably engaged into the second portion ( 6 ), the second portion ( 6 ) having a hole ( 7 ) at one end for engaging with the pegs ( 5 ) of the first portion ( 4 ), thereby providing height adjustment. Alternatively, the adjustable pole ( 10 ) could have a twist-to-tighten collar rather than the engaging peg ( 5 ) and hole ( 7 ). The scope of the invention is not intended to be limited to the type, kind or manner of engagement for providing height adjustment of the adjustable pole either now known or later developed in the future.
[0022] The end of the second portion ( 6 ) of the adjustable pole ( 10 ) that is opposite the hole ( 7 ) is affixed to the base ( 9 ), which has a collar ( 8 ) for accepting the adjustable pole ( 10 ). The collar ( 8 ) may be affixed to the second portion ( 6 ) of the adjustable pole ( 10 ) using a peg and hole, nut and bolt, pin and hole, threaded twisting or screwing technique, or other suitable engaging techniques. The base ( 9 ) is arranged in a cross-beam or x-shaped manner for support and should be sufficiently wide to provide suitable solid support for the paint can stand ( 1 ). The scope of the invention is not intended to be limited to the shape of the base or collar affixing techniques either now known or later developed in the future.
[0023] The paint can stand ( 1 ) is adjustable from one to three feet or three to six feet, but the scope of the invention is not intended to be limited to the adjustable size either now known or later developed in the future.
[0024] FIG. 3 shows another embodiment of the invention, which is substantially similar in structure and function to the embodiment of FIG. 1 . As shown in FIG. 3 , the alternative embodiment of the present invention features a paint can stand ( 1 ′) having a basket ( 2 ′) for engagement with a paint can, the basket ( 2 ′) being affixed to an adjustable pole ( 10 ′) via a coupler ( 12 ), the adjustable pole ( 10 ′) being configured for height adjustment of the stand ( 1 ′), and the adjustable pole ( 10 ′) further being affixed to a base ( 9 ′) for support. The basket ( 2 ′) is cylindrical in shape and sufficiently wide and deep to contain a standard paint can, and may be comprised of a light band metal. The scope of the invention is not intended to be limited to the type or kind of material of which the basket is comprised of either now known or later developed in the future.
[0025] Affixed to the basket ( 2 ′) is an easy-swing handle ( 3 ′) used for carrying the paint can stand ( 1 ′). The handle ( 3 ′) is semi-circular in shape and is affixed to opposite sides of the basket ( 2 ′). The handle ( 3 ′) rests alongside the basket ( 2 ′) when in the resting position and is in an arced position above the stand when being carried. The handle ( 3 ′) is dimensionally sized to be able to make a full arc swing from side to side while a standard gallon-size paint can is situated inside the basket ( 2 ′).
[0026] The adjustable pole ( 10 ′) comprises two portions, which may be comprised of aluminum or steel. The scope of the invention is not intended to be limited to the type or kind of material from which the adjustable pole is made either now known or later developed in the future. The first portion ( 4 ′) is a hollow cylindrical tube affixed at one end to the supportive bottom surface of the basket ( 2 ′). The bottom surface of the basket ( 2 ′) has a collar ( 12 ) for accepting the first portion ( 4 ′) of the adjustable pole ( 10 ′). The collar ( 12 ) may be affixed to the first portion ( 4 ′) of the adjustable pole ( 10 ′) using a peg and hole, nut and bolt, pin and hole, threaded twisting or screwing technique, or other suitable engaging techniques. The scope of the invention is not intended to be limited to the collar affixing techniques either now known or later developed in the future. Affixed to the first portion ( 4 ′) of the adjustable pole ( 10 ′) are evenly spaced pegs ( 5 ′) for engaging with the second portion ( 6 ′) of the adjustable pole ( 10 ′). The pegs ( 5 ′) may utilize compressive technique configured for allowing the pegs ( 5 ′) to be compressed into the inner hollow portion of the tube when a compressing force is applied. Such compressive techniques are known in the art, and the scope of the invention is not intended to be limited to any particular type or kind either now known or later developed in the future. The second portion ( 6 ′) is a hollow cylindrical tube having a slightly larger diameter than the first portion ( 4 ′) such that the first portion ( 4 ′) can be slidably engaged into the second portion ( 6 ′), the second portion ( 6 ′) having a hole ( 7 ′) at one end for engaging with the pegs ( 5 ′) of the first portion ( 4 ′), thereby providing height adjustment. Alternatively, the adjustable pole ( 10 ′) could have a twist-to-tighten collar rather than the engaging peg ( 5 ′) and hole ( 7 ′). The scope of the invention is not intended to be limited to the type, kind or manner of engagement for providing height adjustment of the adjustable pole either now known or later developed in the future.
[0027] The end of the second portion ( 6 ′) of the adjustable pole ( 10 ′) that is opposite the hole ( 7 ′) is affixed to the base ( 9 ′), which has a collar ( 8 ′) for accepting the adjustable pole ( 10 ′). The collar ( 8 ′) may be affixed to the second portion ( 6 ′) of the adjustable pole ( 10 ′) using a peg and hole, nut and bolt, pin and hole, threaded twisting or screwing technique, or other suitable engaging techniques. The base ( 9 ′) is arranged in a cross-beam or x-shaped manner for support and should be sufficiently wide to provide suitable solid support for the paint can stand ( 1 ′). The scope of the invention is not intended to be limited to the shape of the base or collar affixing techniques either now known or later developed in the future.
[0028] The paint can stand ( 1 ′) is adjustable from one to three feet or three to six feet, but the scope of the invention is not intended to be limited to the adjustable size either now known or later developed in the future.
BEST MODE FOR CARRYING OUT THE INVENTION
[0029] FIG. 1 shows the assembled paint can stand as described. FIG. 2 shows the separate elements of the paint can stand of FIG. 1 .
THE SCOPE OF THE INVENTION
[0030] It should be understood that, unless stated otherwise herein, any of the features, characteristics, alternatives or modifications described regarding a particular embodiment herein may also be applied, used, or incorporated with any other embodiment described herein.
[0031] Although the invention has been described and illustrated with respect to exemplary embodiments thereof, the foregoing and various other additions and omissions may be made therein without departing from the spirit and scope of the present invention. | A paint can stand is provided comprising a basket, an adjustable pole engaged with the basket, and a base configured for removable engagement with the adjustable pole. The adjustable pole has a first and second portion, the first portion having pegs extending outwardly therefrom, and the second portion having a hole dimensionally sized for engaging with the pegs. The base has a collar configured to receive the adjustable pole. | 5 |
FIELD OF THE INVENTION
The present invention relates to implantable diagnostic apparatuses for determining analytes and methods for their use.
BACKGROUND
Implantable diagnostic apparatuses have already been described, for example, as parts of implantable insulin pumps. Such apparatuses essentially comprise an implantable measurement chamber in which a biosensor generates an analyte-dependent signal which, for its part, serves to control the insulin pump. These apparatuses have to be exchanged periodically when the insulin reserve is exhausted. Since this exchange takes place relatively frequently, the exchange interval is frequently shorter than the service life of the biosensors.
What is disadvantageous in the case of previous methods, and probably also a reason why the previous methods for glucose determination in connection with insulin pumps have not been applied to other parameters, is the problem that would arise if the biosensors are in contact with blood over a relatively long period of time and then their function is impaired, or even rendered impossible, by deposits such as, for example, fat- or protein-containing deposits (clots).
In particular, methods for determining coagulation parameters, which, by their nature, are often associated with clot formation, are not considered to be promising.
The object underlying the present invention is to provide an implantable diagnostic apparatus which enables the intervals between the exchanges of the apparatuses to be significantly lengthened and which allows the detection of coagulation and fibrinolysis parameters to determine hemostasis disturbances, e.g. by detecting factor VIII or measuring the PT (prothrombin) time.
It has been found, surprisingly, that the apparatus according to the invention, either as an individual measurement chamber or as an apparatus containing a plurality of measurement chambers, can advantageously be used to determine hemostasis disturbances, i.e. any malfunction of the hemostasis system.
SUMMARY OF THE INVENTION
The present invention relates to a diagnostic apparatus for determining analytes, which comprises at least (i) one measurement unit for single or continuous determination of an analyte, wherein the measurement unit generates a signal in the presence of the analyte to be determined; (ii) a signal transmission unit capable of converting that signal and capable of forwarding it to a signal-processing unit or forwarding the unconverted signal to a signal-processing unit; and (iii) a sample feeder to the measurement unit(s) which extends into the relevant liquid-containing body compartment, for instance a blood vessel. A light source which radiates a light suitable for exciting photosensitizers, preferably such as those as disclosed in EP-A2-0 515 194 (incorporated herein by reference), projects into the measurement chamber of said measurement unit. The surface within the measurement chamber shall be at least partly conductive or alternatively, the measurement chamber shall contain a light receiver. The measurement chamber preferably contains photosensitizers, especially photosensitizers incorporated into so-called sensitizer beads, capable of producing oxygen radicals after illumination. The analytes to be determined react with photosensitizers in such a way that the photosensitizers yield, depending on the analyte's concentration or activity, singlet oxygen which is measured by electrodes and converted into a transmittable signal. Alternatively, the signal is generated in the presence of analytes by photosensitizers that are in close proximity with acceptors, which might be incorporated into so-called acceptor beads, and the singlet oxygen generated by the photosensitizers activates said acceptors which subsequently produce light, and said light is detected. Acceptors preferably comprise substances such as described as a chemiluminescent compound in EP-A2-0 515 194.
The present invention relates fither to methods for determining analytes or their activity, preferably for the detection of hemostatsis disturbances, comprising an diagnostic apparatus as described above (i) wherein the analytes react with photosensitizers in such a way that the photosensitizers yield, depending on the analyte's concentration or activity, singlet oxygen which is measured by electrodes and converted into a transmittable signal; or (ii) wherein in the presence of analytes the signal is generated by photosensitizers that are in close proximity with acceptors and the singlet oxygen generated by the photosensitizers activates said acceptors which subsequently produce light, and said light is detected.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the scheme of one preferred embodiment of such a diagnostic apparatus comprising a signal-processing unit and a diagnostic measurement device (DND) with a cannula, which is implanted under the skin in such a way that the cannula projects into a blood vessel. The cannula contains a filter which ensures that cellular constituents of the blood are excluded from the measurement chamber(s) within the DND, with the result that plasma is used in the analysis.
FIG. 2A shows the scheme of one embodiment of a measurement chamber: The interior of the measurement chamber can be illuminated directly by an light source, e.g. a small light-emitting diode, or indirectly via an optical waveguide. The measurement chamber can be closed or opened, e.g. by magnetically actuable closure flaps. At least a part of the surface of the measurement chamber is conductive.
FIG. 2B shows a cross-section through a measurement device comprising a multitude of measuring chambers which are connected with a blood stream.
FIG. 3 illustrates a cross-section through the measurement chamber: Photosensitizers, preferably sensitizer beads, generating singlet oxygen on excitation, are applied, in the measurement chamber, together with analyte-specific reagents. A light source which radiates a light suitable for exciting the sensitizer beads projects into the measurement chamber. When coagulation takes place, the mobility of the sensitizer beads is altered by the fibrin network of the clot, and, as a result, sensitizer beads accumulate on the conductive surface. In the case of immunochemical reactions, corresponding binding partners such as antibodies are immobilized on the surface of the measurement chamber. As a result of the binding of the sensitizer beads to the analyte to be detected, which is bound to the binding partner of the surface, the sensitizer beads are brought into the vicinity of the conductive surface of the measuring chamber. Excitation of the sensitizer beads with light generates oxygen radicals which will generate a measurable signal if the conductive surface is within the effective range of the oxygen radicals. Due to the limited range in aqueous medium, only those oxygen radicals produced by sensitizer beads which are in close proximity to the conductive surface, e.g., by clot formation or by the immunochemical reaction, will reach the conductive surface and cause a measurable current flow.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to a diagnostic apparatus for determining analytes, which comprises at least (i) one measurement unit for single or continuous determination of an analyte, wherein the measurement unit generates a signal in the presence of the analyte to be determined; (ii) a signal transmission unit capable of converting that signal and capable of forwarding it to a signal-processing unit or forwarding the unconverted signal to a signal-processing unit; and (iii) a sample feeder to the measurement unit(s) which extends into the relevant liquid-containing body compartment, for instance a blood vessel.
Determining analytes in the sense of the present invention means the detection of the analyte, measuring the analyte's concentration or its activity such as its enzymatic or binding activity. The analytes are the substances or compounds usually measured in a clinical laboratory to detect any diseases or to check a person's health (see also EP-A2-0 515 194), especially blood clotting factors and plasma proteins such as antibodies or peptide hormones.
In a preferred embodiment of the diagnostic apparatus, a light source which radiates a light suitable for exciting photosensitzers projects into the measurement chamber of said measurement unit, and the surface of the measurement chamber shall be at least partly conductive or, the measurement chamber shall comprise a light receiver. The measurement chamber preferably contains photosensitizers, preferably such as those as disclosed in EP-A2-0 515 194 and especially photosensitizers incorporated into so-called sensitizer beads, capable of producing oxygen radicals after illumination. The analytes to be determined react with photosensitizers in such a way that the photosensitizers yield, depending on the analyte's concentration or activity, singlet oxygen which is measured by electrodes and converted into a transmittable signal. Alternatively, the signal is generated in the presence of analytes by photosensitizers that are in close proximity with acceptors, which might be incorporated into so-called acceptor beads, and the singlet oxygen generated by the photosensitizers activates said acceptors which subsequently produce light, and said light is detected. Acceptors preferably comprise substances such as described as a chemiluminescent compound in EP-A2-0 515 194.
The diagnostic apparatus shall be implanted preferably outside a blood vessel. It shall usually not exceed an external dimension of 1500 μl, preferably of 500 μI, particularly preferably of 400 μl, especially preferably of 300 μl. The measurement unit of the diagnostic apparatus may be used only once or as long as its functionality is ensured. The diagnostic apparatus may comprise a plurality of measurement units, and is used for determining one single analyte or for determining different analytes. The energy necessary for signal generation and/or transmission is normally generated by a concomitantly implanted battery or is fed in by an external transducer.
The apparatus according to the invention comprises one or more measurement chambers which, in turn, essentially comprise three parts, to be precise the actual measurement chamber, a cannula which protrudes therefrom and, for its part, projects into a liquid-containing body compartment, such as a blood vessel, in whose fluid is the analyte to be determined. Furthermore, a signal transmission unit is associated with each measurement chamber—or else with all the measurement chambers together. The vessel end of the cannula may advantageously be closed off by a filter, which allows the passage of the analytes but excludes cells. The cannulae are furthermore provided with a closure flap which can be actuated by the action of an extracorporeal signal.
The diagnostic apparatus is advantageously additionally provided with an apparatus for storing the measurement signals, which can then be called up as required.
A preferred embodiment of the measurement chamber is illustrated in FIG. 2 .
A plurality of said measurement chambers are advantageously combined to form a diagnostic apparatus, the number of individual measurement chambers preferably being from 20 to 50. The number as such is non-critical; if one determination per week is assumed, then a number of 50±10 appears to be particularly advantageous since one exchange per year is sufficient in this case.
The inventive method and device can be furished both for flow rate measurements and for individual determinations. The possibility of contactless signal transmission means that it can advantageously be used both for in- and outpatients, without additionally restricting the patients' mobility. The signal transmission methods are known per se to a person skilled in the art. The structure of one embodiment of the device is illustrated in FIG. 1 . The structure of a specific measurement chamber is illustrated in FIG. 2 A. The production of sufficiently small measurement chambers is possible by the methods which are known per se to a person skilled in the art.
The closure of the measurement chambers is especially important. Magnetically actuable closure flaps which can assume two fixed states (flip-flops) can advantageously be used here. FIG. 2B illustrates an arrangement of a plurality of measurement chambers. The supply of light to the individual measurement chambers can in this case be effected for example either via correspondingly small light sources, for example light-emitting diodes, arranged separately for each measurement chamber or via corresponding optical waveguides.
Each measurement chamber advantageously contains the reagent or reagents necessary for the reaction, for example, thromboplastin for a PT (prothrombin time) determination or antibodies or antigens for an immunochemcal reaction.
The present invention relates further to methods for determining analytes or their activity, preferably for the detection of hemostatsis disturbances, comprising an diagnostic apparatus as described above (i) wherein the analytes react with photosensitizers in such a way that the photosensitizers yield, depending on the analyte's concentration or activity, singlet oxygen which is measured by electrodes and converted into a transmittable signal; or (ii) wherein in the presence of analytes the signal is generated by photosensitizers that are in close proximity with acceptors and the singlet oxygen generated by the photosensitizers activates said acceptors which subsequently produce light, and said light is detected.
In a preferred embodiment of the invention, a coagulation process is initiated in the measurement unit and the course of the coagulation is determined by following a suitable parameter.
The inventive technology is difficult to realize using the customary determination methods employed in coagulation. A new technology is advantageously employed, which new technology is described below:
Thus, for example, photosensitizers, preferably sensitizer beads generating singlet oxygen, which are described in EP-A2-0 515 194, for example, can be used. These sensitizer beads are applied, in the measurement chamber, to a conductive surface made of carbon, for example, together with the analyte-specific reagents. A light source which radiates a light suitable for exciting the sensitizer beads projects into the measurement chamber. When coagulation takes place, the mobility of the sensitizer beads is altered, as a rule restricted, and, as a result, sensitizer beads accumulate on the conductive surface and a measurable current flow is produced (also see FIG. 3 ).
An analogous method can be employed for immunological determinations, where a specific binding partner is immobilized on the conductive surface and sensitizer beads which are likewise coated with a binding partner specific to the analyte are bound by the analyte in the vicinity of the conductive surface, which again leads to a measurable change in the current flow.
An advantageous embodiment can be designed as follows:
A device comprising the elements of a measurement unit, a signal-processing unit and also a cannula is implanted under the skin, with the result that the cannula projects into a vessel. The units are produced by means of microtechnology of the kind used for example in the fabrication of integrated circuits (chip technology) and, as a result, are small enough that they can be implanted using known endoscopic techniques. For the measurement, an external receiver is emplaced and the current for the measurement is transmitted conductively. At the same time, the measurement signals or results are transmitted to the receiver, where they can be interrogated.
The measurement unit comprises discrete measurement chambers which can be individually closed off by valves and can be used just once, and also a pump apparatus connected to the cannula, and also, if appropriate, to a supply reservoir containing physiological NaCl for flushing the cannula. Furthermore, the measurement unit contains a light generator, for instance a microlaser, and also current lines for deriving and processing the measurement signal. The measurement chamber contains a miniaturized diode or is connected to the central light generator via an optical waveguide. The measurement chamber contains the reagents which are necessary for detecting the plasma protein or for the coagulation analysis. The methods for producing the discrete components, such as valves or pumps, for example, are known per se to a person skilled in the art.
The detection of the reaction is carried out by means of a novel combination of sensitizer beads with an amperometrically sensitive printed circuit board. Excitation with light generates oxygen radicals which generate a measurable signal on the printed circuit board. In the event of clot formation, said radicals are preferably produced in the vicinity of the printed circuit board, on account of the immobilization. The free solution can be kept in motion by stirrers. In the case of immunochemical reactions, corresponding binding partners are immobilized on the surface. As a result of the binding of the sensitizer beads to the analyte to be detected, which is bound to the binding partner of the surface, the sensitizer beads are brought into the vicinity of the printed circuit board, thereby transferring a charge (oxygen radicals) to the printed circuit. The measurement signal is thus proportional to the analyte concentration. As an alternative, it is also possible to use such reagents as described in EP-A2-0 515 194, comprising sensitizer and acceptor beads. The measurement chamber would then contain a light receiver instead of a printed circuit board.
The signal-processing unit contains a computing processor and also a transducer for transmission of the results, and also further electrical units for receiving energy.
The cannula may contain filters which ensure that cellular constituents of the body liquids are excluded, with the result that in case of blood as the body liquid, plasma is used in the analysis. After the measurement, access ducts, cannula and filter can be cleaned by backward flushing with physiological sodium chloride solution. | The present invention relates to an implantable diagnostic apparatus for determining analytes in body fluids, which comprises a plurality of identical and/or different measurement units for determining an analytic parameter, in which a signal is generated which is specifically related to the variable to be determined and is transmitted by means of suitable measures to a receiver situated outside the body. | 8 |
RELATED APPLICATIONS
[0001] This application claims priority to U.S. provisional application 62/091,362 filed Dec. 12, 2014 which is hereby incorporated by reference in its entirety.
BACKGROUND
[0002] The use of high-throughput microarrays is gaining increasing acceptance as a method for the screening of libraries of biomolecules, such as DNA, proteins, peptides and sugars (1-4). One of the key factors affecting the efficiency and specificity of a microarray experiment is the method used to attach the probes to the solid support. During the last decade click chemistry became a very efficient and cost-effective method of molecule immobilization (5). The basic foundations of click chemistry were developed by Sharpless et al. (5, 7). To date, various modifications of this reaction are known (8).
[0003] However, the most suitable variant for microarray construction seems to be the copper (Cu(I))-catalyzed variant of alkyne-azide cycloaddition (CuAAC) (9, 10). Typically, this cycloaddition reaction is simple and easy to perform and is compatible with many functional groups. This has been demonstrated by the covalent and orthogonal attachment of biomolecules to solid surfaces to fairly rapidly prepare microarrays (11-13).
[0004] Surface chemistries for solid phase assays can be categorized into mono-, two- or three dimensional, based on their architectures (14). Strategies enabling a distribution of immobilization points within the thickness of the coating are generally called “three-dimensional” (3D) coatings and are known to produce better signal-to-noise ratios, and wider dynamic ranges through a unique combination of characteristics that include low non-specific binding and high probe loading capacity (15).
[0005] A need exists for better arrays and materials to prepare the arrays, wherein high sensitivity, superior signal-to-noise ratio, and good yields can be achieved. 3D coatings enabling the attachment via click chemistry of biomolecules (e.g., peptides and proteins, nucleic acid compounds such as DNA and RNA, lipids, and carbohydrates such as glycans) in a functionally active form with proper orientation satisfy this need and have the potentiality of finding wide application in microarray technology.
[0006] In addition, needs exist to discover better materials to enable separations, including electrophoretic separations.
SUMMARY
[0007] Embodiments described herein include compositions and polymers, and methods of making and using such compositions and polymers including arrays.
[0008] One lead aspect provides for a composition comprising at least one polymer, wherein the polymer comprises a polymeric backbone comprising (or consisting essentially of or consisting of) at least three monomeric repeat units A, B, and C which are different from each other, wherein monomeric repeat unit C comprises at least one side group which comprises at least one optionally protected alkynyl group. This polymer can be uncrosslinked or crosslinked. This polymer, in one embodiment, can be part of a multilayer. This polymer, in one embodiment, can be reacted to form a gel or a hydrogel.
[0009] Another lead aspect is a composition comprising at least one polymer, wherein the polymer comprises a polymeric backbone comprising (or consisting essentially of or consisting of) at least two monomeric repeat units A and C which are different from each other, and optionally comprising at least a third monomeric repeat unit B, wherein monomeric repeat unit A is a substituted acrylamide monomeric repeat unit, and monomeric repeat unit C comprises at least one side group which comprises at least one optionally protected alkynyl group. This polymer can be uncrosslinked or crosslinked. This polymer, in one embodiment, can be part of a multilayer. This polymer, in one embodiment, can be reacted to form a gel or a hydrogel.
[0010] Still another lead aspect is a composition comprising at least one polymer, wherein the polymer comprises a polymeric backbone comprising (or consisting essentially of or consisting of) at least two monomeric repeat units B and C which are different from each other, and optionally comprising at least a third monomeric repeat unit A, wherein monomeric repeat unit B comprises a silane monomeric repeat unit, and monomeric repeat unit C comprises at least one side group which comprises at least one optionally protected alkynyl group. This polymer can be uncrosslinked or crosslinked. This polymer, in one embodiment, can be part of a multilayer. This polymer, in one embodiment, can be reacted to form a gel or a hydrogel.
[0011] In one embodiment, the monomeric repeat unit C comprises at least one side group which comprises at least one optionally protected alkynyl group, wherein the polymer is formed by a functionalization reaction of a pre-polymer to form the optionally protected alkynyl group.
[0012] In one embodiment, the optionally protected alkynyl group is an unprotected alkynyl group. In another embodiment, the optionally protected alkynyl group is an unprotected alkynyl group represented by —C≡C—H.
[0013] In one embodiment, the monomeric repeat unit C comprises at least one side group which comprises at least one optionally protected alkynyl group, wherein the optionally protected alkynyl group is represented by —NH—CH 2 —C≡CH, dibenzocyclooctyne-amine, or dibenzocyclooctyne-PEG-amine (wherein PEG is poly(ethylene glycol). In one embodiment, the optionally protected alkynyl group is a strained cyclooctyne group.
[0014] In one embodiment, the optionally protected alkynyl group is protected. In one embodiment, the optionally protected alkynyl group is protected by a silane group. In one embodiment, the optionally protected alkynyl group is protected and represented by —C≡C—Si(R) 3 , wherein R is a C 1 -C 12 alkyl group. In one embodiment, the optionally protected alkynyl group is protected and represented by —C≡C—Si(CH 3 ) 3 .
[0015] In one embodiment, the monomeric repeat unit A comprises at least one N,N-substituted acrylamide repeat unit and monomer B comprises at least one silane reactive side group. In one embodiment, the polymer comprises an all carbon backbone. In one embodiment, the monomeric repeat units are distributed randomly.
[0016] In one embodiment, the polymer consists essentially of a polymeric backbone comprising (or consisting essentially of) at least three monomeric repeat units A, B, and C which are different from each other, wherein monomeric repeat unit C comprises (or consists essentially of) at least one side group which comprises (or consists essentially of) at least one optionally protected alkynyl group. This polymer can be uncrosslinked or crosslinked. This polymer, in one embodiment, can be part of a multilayer. This polymer, in one embodiment, can be reacted to form a gel or a hydrogel.
[0017] In one embodiment, the polymer consists essentially of a polymeric backbone comprising (or consisting essentially of) at least two monomeric repeat units A and C which are different from each other, and optionally comprising (or consisting essentially of) at least a third monomeric repeat unit B, wherein monomeric repeat unit A is a substituted acrylamide monomeric repeat unit, and monomeric repeat unit C comprises (or consists essentially of) at least one side group which comprises (or consists essentially of) at least one optionally protected alkynyl group. This polymer can be uncrosslinked or crosslinked. This polymer, in one embodiment, can be part of a multilayer. This polymer, in one embodiment, can be reacted to form a gel or a hydrogel.
[0018] In one embodiment, the polymer consists essentially of a polymeric backbone comprising (or consisting essentially of) at least two monomeric repeat units B and C which are different from each other, and optionally comprising (or consisting essentially of) at least a third monomeric repeat unit A, wherein monomeric repeat unit B comprises (or consists essentially of) a silane monomeric repeat unit, and monomeric repeat unit C comprises (or consists essentially of) at least one side group which comprises (or consists essentially of) at least one optionally protected alkynyl group. This polymer can be uncrosslinked or crosslinked. This polymer, in one embodiment, can be part of a multilayer. This polymer, in one embodiment, can be reacted to form a gel or a hydrogel.
[0019] In one embodiment, the polymer consists of a polymeric backbone comprising (or consisting of) at least three monomeric repeat units A, B, and C which are different from each other, wherein monomeric repeat unit C comprises (or consists of) at least one side group which comprises (or consists of) at least one optionally protected alkynyl group. This polymer can be uncrosslinked or crosslinked. This polymer, in one embodiment, can be part of a multilayer. This polymer, in one embodiment, can be reacted to form a gel or a hydrogel.
[0020] In one embodiment, the polymer consists of a polymeric backbone comprising (or consisting of) at least two monomeric repeat units A and C which are different from each other, and optionally comprising (or consisting of) at least a third monomeric repeat unit B, wherein monomeric repeat unit A is a substituted acrylamide monomeric repeat unit, and monomeric repeat unit C comprises (or consists of) at least one side group which comprises (or consists of) at least one optionally protected alkynyl group. This polymer can be uncrosslinked or crosslinked. This polymer, in one embodiment, can be part of a multilayer. This polymer, in one embodiment, can be reacted to form a gel or a hydrogel.
[0021] In one embodiment, the polymer consists of a polymeric backbone comprising (or consisting of) at least two monomeric repeat units B and C which are different from each other, and optionally comprising (or consisting of) at least a third monomeric repeat unit A, wherein monomeric repeat unit B comprises (or consists of) a silane monomeric repeat unit, and monomeric repeat unit C comprises (or consists of) at least one side group which comprises (or consists of) at least one optionally protected alkynyl group. This polymer can be uncrosslinked or crosslinked. This polymer, in one embodiment, can be part of a multilayer. This polymer, in one embodiment, can be reacted to form a gel or a hydrogel.
[0022] In one embodiment, the polymer is represented by DMA-PMA-MAPS, copolymerized N, N-dimethylacrylamide (DMA), 3-trimethylsilanyl-prop-2-yn methacrylate (PMA) and 3(trimethoxysilyl)-propylmethacrylate (MAPS). In one embodiment, the PMA is deprotected.
[0023] In another aspect, provided is a composition prepared by reaction of a polymer composition as described and/or claimed herein, wherein the polymer is in an unprotected form, with at least one compound. The compound can be an azide compound. The compound can be, for example, not limited by a particular molecular weight but can be a small molecule or polymer. The polymer can be a biomolecular compound. The polymer can be a synthetic polymer.
[0024] In another embodiment, provided is a composition prepared by reaction of a polymer composition as described and/or claimed herein, wherein the polymer is in an unprotected form, with at least one biomolecular compound, which optionally is a glycan compound. In another embodiment, the biomolecular compound, which optionally is a glycan compound, comprises an azide moiety.
[0025] Another aspect is an article comprising at least one substrate coated with a composition as described and/or claimed herein. In one embodiment, the article is a microarray. In another embodiment, the article can be a device for separation.
[0026] Another aspect is a method of forming the polymer composition as described and/or claimed herein, wherein the method comprises polymerizing at least one first monomer C′ which provides for monomeric repeat unit C, with one or both of monomers A′ and B′ which provide for monomeric repeat unit A and B, respectively. The monomer C′ can either directly provide the monomeric repeat unit C, or it can provide a precursor which upon a post-polymerization reaction can form the monomeric repeat unit C.
[0027] In one embodiment, the polymerizing is carried out by free radical polymerization. In another embodiment, the polymerizing is carried out with monomers A′, B′, and C′.
[0028] Another aspect is a method of carrying out a test, such as a binding test, wherein the method comprises exposing an article as described and/or claimed herein to a composition comprising at least one biomolecule.
[0029] In one aspect, the composition as described and/or claimed herein is crosslinked. In one aspect, the composition as described and/or claimed herein is a gel or is a hydrogel. In one embodiment, the prepared composition is a hydrogel comprising poly(alkylene glycol) polymer.
[0030] Another aspect is a method for separation comprising separating components, wherein a composition as described and/or claimed herein is used as a separation agent. Another aspect is a method for electrophoretic separation comprising electrophoretically separating components, wherein a composition as described and/or claimed herein is used as a electrophoretic sieving matrix.
[0031] Another aspect is an article as described and/or claimed herein, wherein the substrate of the article is coated with a multi-layer comprising a composition as described and/or claimed herein.
[0032] Another aspect is an article as described and/or claimed herein, wherein the multi-layer comprises at least three layers, and the surface layer comprises the composition as described and/or claimed herein.
[0033] One or more advantages in various embodiments are noted throughout the rest of this application.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] FIG. 1 : Chemical formula of 11 compounds: azide cyanine dye (1), α-mannose derivatives (2-9) positive (10, α-mannose) and negative (11, β-galactose) controls.
[0035] FIGS. 2( a ) and ( b ) : Mean fluorescence intensity of the glycomimetics of FIG. 1 (11 replicates per line) incubated with 100 ng/ml of biotynilated ConA (0.943 nM) and revealed with Cy3 labeled streptavidin, (a) image of the glycomimetic microarray; (b) histogram of spot fluorescence intensity of 11 spot replicates.
[0036] FIG. 3 : Synthesis of the poly(DMA-PMA-MAPS) copolymer. In brackets are the molar fractions of the monomers.
[0037] FIG. 4 : Reaction scheme of a typical click reaction between the surface and the glycan.
[0038] FIG. 5 : Dependence of surface immobilization density on the concentration of the solution spotted
[0039] FIGS. 6( a ) and ( b ) : Fluorescence vs log([ConA]) in a sigmoidal/growth graph. Both the glycomimetics (3 and 5) were spotted at 50 μM printing concentration. The bars represent the standard deviation of each mean fluorescence. (a) is the trend of a glycan with higher affinity for ConA (0.436 nM) while (b) is the trend of a glycan with a lower affinity with the lectin (3.45 nM).
[0040] FIG. 7 . Separation of DNA fragments in a “click” gel (Example 2).
[0041] FIG. 8 . DNA microarray of different slides with multilayers of “click” functional polymers, upper showing spots and lower showing fluorescent intensity for layer one or layer three (Example 3).
DETAILED DESCRIPTION
Introduction
[0042] Microarrays are known in the art. See, for example, Muller and Roder, Microarrays , Elsevier, 2006 and Kohane, Kho, Butte, Microarrays for an Integrative Genomics , MIT Press, 2003. See also, for example, U.S. Pat. No. 8,809,071 and WO 2011/124715 which describe copolymers which can be used in microarrays and which is hereby incorporated by reference in its entirety.
[0043] In the lead aspect, provided is a composition comprising at least one polymer, wherein the polymer comprises a polymeric backbone comprising (or consisting essentially of, or consisting of) at least three monomeric repeat units A, B, and C which are different from each other, wherein monomeric repeat unit C comprises at least one side group which comprises at least one optionally protected alkynyl group. In some embodiments, monomeric repeat unit A may be omitted, and in some embodiments, monomeric repeat unit B may be omitted. Each of these elements is described in more detail herein below.
[0044] The polymeric backbone can be an all-carbon backbone represented by —[CH 2 —CHR] n —; wherein R is for the different side groups which will provide for the monomeric repeat units A, B, and C. In some embodiments, at least 90 mole %, or at least 95 mole %, or at least 99 mole % of the monomer repeat units are units A, B, and C. The different monomeric repeat units can be substantially randomly arranged in the backbone, or they can be arranged with some order. Other monomer repeat units such as D or E can be present, but in a preferred embodiment, the polymer backbone consists of or consists essentially of the repeat units A, B, and C.
[0045] The number average molecular weight can be, for example, about 5,000 to about 100,000, or about 10,000 to about 50,000.
[0046] The polymer can be purified by methods known to the person skilled in the art such as precipitation, extraction, and the like.
Monomeric Repeat Unit C, Alkynyl Groups, Protected and Unprotected Forms
[0047] The monomeric repeat unit C can provide the polymer with the function of reacting with a biomolecule by Cu(I))-catalyzed of alkyne-azide cycloaddition, a method known in the art as an example of “click chemistry” rather than more conventional “nucleophilic reactions.”
[0048] Apart from the Cu(I)-catalyzed 1,3-dipolar cycloaddition of alkyne and azide groups (CuAAC reaction) for forming the polymer reaction product, also another type of related reaction can be used, the so called Strain-promoted Azide-Alkyne Click Chemistry (SPAAC) reaction. The requirement of a cytotoxic copper catalyst can limit the usage of CuAAC reactions. A Copper free method is the SPAAC reaction [Jewett et al. (2010), “Cu-free click cycloaddition reactions in chemical biology,” Chem. Soc. Rev. 39(4):1272]. SPAAC reactions rely on the use of strained cyclooctynes that possess a remarkably decreased activation energy in contrast to terminal alkynes and thus do not require an exogenous catalyst [Ess et al (2008), “Transition states of strain-promoted metal-free click chemistry: 1,3-dipolar cycloadditions of phenyl azide and cyclooctynes,” Org. Lett. 10: 1633]. In this embodiment, the alkyne group of the polymer is a strained cyclooctyne that can be introduced into the polymer by post modification reaction with, for example, dibenzocyclooctyne-amine (DBCO).
[0049] The SPAAC reaction can be used to form a variety of polymers and types of polymers in various applications including, for example, gels, hydrogels, and multilayers as described more hereinbelow.
[0050] In one embodiment, the optionally protected alkynyl group is an unprotected alkynyl group. More particularly, the optionally protected alkynyl group is in one embodiment an unprotected alkynyl group represented by —C ≡C—H.
[0051] In another embodiment, the optionally protected alkynyl group is protected. In one embodiment, the optionally protected alkynyl group is protected by a silane group. In one embodiment, the protected alkynyl group is represented by —C≡C—Si(R) 3 , wherein R is, for example, a C 1 -C 12 alkyl group. In one embodiment, the optionally protected alkynyl group is represented by —C≡C—Si(CH 3 ) 3 .
[0052] Monomeric repeat unit C can result from use of monomers called C′.
[0053] In addition, monomeric repeat unit C can be provided through reaction of a pre-cursor, reactive polymer. For example, a monomer can be used which is functionalized to react to prepare a polymer which has the functional groups ready to react. These functional groups (e.g., an active ester such as a succinimidyl ester) can be reacted with a multi-functional group such as propargylamine which provides the polymer with the alkyne functional groups.
Monomeric Repeat Unit A
[0054] The monomeric repeat unit A can provide the function of having the polymer absorb to the substrate surface. See, for example, U.S. Pat. No. 8,809,071 and WO 2011/124715. For example, the monomeric repeat unit can be a polymerized acrylamide moiety including, for example, a monomeric repeat unit which comprises at least one N,N-substituted acrylamide repeat unit such as polymerized dimethylacrylamide. Monsubstituted acrylamide can also be used. Monomeric repeat unit A can result from use of monomers called A′.
Monomeric Repeat Unit B
[0055] The monomeric repeat unit B can provide the function of stabilizing the absorbed film by covalently reacting with functional groups present on the surface. See, for example, U.S. Pat. No. 8,809,071 and WO 2011/124715. Monomeric repeat unit C can comprise at least one silane reactive side group. Monomeric repeat unit B can result from use of monomers called B′.
Method of Making Polymer
[0056] Also provided herein are methods of making polymers and the polymers which results from these methods. For example, one embodiment is a method of forming the polymer composition as described herein, wherein the method comprises polymerizing at least one first monomer C′ which provides for monomeric repeat unit C, with one or both of monomers A′ and B′ which provide for monomeric repeat unit A and B, respectively. In one embodiment, the polymerizing is carried out by free radical polymerization. In one embodiment, the polymerizing is carried out with monomers A′, B′, and C′.
Method of Using the Polymer
[0057] One embodiment is a method of carrying out a binding test, wherein the method comprises exposing an article as described herein to a composition comprising at least biomolecule such as, for example, one or more azido-modified biomolecules. The biomolecule can bind with the article. Biomolecules include, for example, glycans, proteins, and DNA peptides. Any biomolecule which can be azide-modified can be used.
Derivatized Form of the Polymer
[0058] One embodiment is a composition prepared by reaction of a polymer composition as described herein, wherein the polymer is in an unprotected form, with at least one compound such as a biomolecule. In one embodiment, the compound is a glycan compound. Other embodiments include, for example, proteins and DNA peptides. The biomolecule such as a glycan compound can comprise an azide moiety.
[0059] The polymer can also be derivatized or crosslinked to form a crosslinked form of the polymer including a gel or hydrogel.
[0000] Articles with Polymer
[0060] One embodiment is an article comprising at least one substrate coated with the compositions described herein. In a lead embodiment, the article is a microarray.
[0061] Substrates are known in the art and include, for example, glass, plastic, materials used in the semiconducting industry such as Si or SiO 2 , and the like. Substrates can be insulators, electronic conductors, or semiconductors.
[0062] The substrates can be coated with polymer films as described herein. Film thickness can be, for example, 1 nm to 100 nm, or 2 nm to 50 nm.
PREFERRED EMBODIMENTS AND WORKING EXAMPLES
[0063] Herein, in a preferred embodiment and in working examples, the inventor describes a novel substrate for the fabrication and screening of glycan arrays combining the high sensitivity and superior signal-to-noise ratio of polymer-coated Si—SiO 2 wafers with the immobilization by the cupper catalyzed azide/alkyne ‘click’ reaction 18 on a 3D coating. The inventor reports here in a preferred embodiment and working examples for the first time the synthesis and characterization of the novel clickable polymer and its use to form a coating on a Si/SiO 2 wafer for the highly sensitive detection of mono- and oligosaccharide/proteins interactions.
[0064] In this preferred embodiment and working examples, the proposed click conjugation chemistry, featuring quantitative yields, high tolerance of functional groups as well as insensitivity to solvents, fulfills many requirements for the immobilization of sugar ligands onto polymer coated supports, and it can be potentially extended to the immobilization and analysis of glycomimetic structures.
[0065] Herein, in a preferred embodiment and working examples, the inventor(s) introduce a new polymer obtained from the polymerization of N,N-dimethylacrylamide (DMA), 3-trimethylsilanyl-prop-2-yn methacrylate (PMA) and 3(trimethoxysilyl)-propylmethacrylate (MAPS), copoly (DMA-PMA-MAPS) and describe its use in the formation of a functional coating for microarrays. The backbone of the polymer bears alkynyl side group moieties that allow binding azide-modified glycans to the surface by “Click” chemistry. This attachment mode offers a number of advantages in the immobilization of biomolecules such as glycans, such as high grafting efficiency, oriented immobilization and insensitivity to functionalities present in natural glycans. The novel surface chemistry was used to prepare microarrays substrates for fluorescence microarray on Si/SiO 2 slides. The higher sensitivity to the fluorescence signal provided by the novel Si/SiO 2 microarray substrate offers significant advantages over conventional glass slides allowing analysis at lower glycan surface density.
[0066] Eight α-mannoside derivatives, immobilized on the polymer-modified substrate, were screened against the mannose-binding lectin Concanavalin A (Con A), using α-mannose as the positive control and β-galactose as the negative control. The array analysis showed specific interactions of the mannosylated support with ConA with a high signal-to-noise ratio. At the highest surface densities of mannose derivatives, dissociation constants on the order of 1 nM were calculated from fluorescence microarray experiments. The surface equilibrium dissociation constant (K D ) of the interaction was found to depend strongly on the surface concentration of glycans. The fluorescence detection enhanced by the Si/SiO 2 substrates enabled the study of density dependent, binding properties of Concanavalin A even at low glycan density and to determine surface equilibrium constants in solution-like conditions.
WORKING EXAMPLES
[0067] Additional embodiments are provided in the following non-limiting working examples:
1. Materials and Methods
1.1 Materials
[0068] Trimethylsilylpropyn-1-ol, triethylamine (TEA), diethyl ether (Et 2 O), methacryloyl chloride (CH 2 CCH 3 COCl), dry tetrahydrofuran (THF), α,α′-azoisobutyronitrile (AIBN), petroleum ether (EtP), potassium carbonate (K 2 CO 3 ), copper sulphate penta-hydrate (Cu 2 SO 4 .5H 2 O), ascorbic acid, biotinylated ConcanavalinA (ConA), streptavidin-cyanine3, phosphate saline buffer (PBS), Bovin Serum Albumin (BSA), trizma base (Tris), chloridric acid (HCl), sodium chloride (NaCl), Tween 20, manganese chloride (MnCl 2 ), calcium chloride (CaCl 2 ), sodium hydroxide (NaOH), N-(2-hydroxyethyl)piperazine-N′-(2-ethanesulfonic acid) (HEPES) were purchased from Sigma Aldrich (St. Louis, Mo., USA). Cyanine3 azide was purchased from Lumiprobe GmbH (Feodor-Lynnen Strasse 23, 30625 Hannover, Germany). All solvents were used as received.
[0069] Silicon oxide chips with a 100 nm thermal oxide layer were bought from Silicon Valley Microelectronics (Santa Clara, Calif., USA). The glass substrates with a silicon dioxide anti-reflection layer used in some experiments were provided by ODL S.r.l. (Brembate Sopra, Bergamo, Italy). An Agilent 1200 series liquid chromatography system, (Agilent Technologies, Santa Clara, Calif., USA) was used to carry out GCP. GPC columns were from Schodex (New York, N.Y., USA); MALLS system was purchased from Wyatt Technology (Santa Barbara, Calif., USA).
1.2 Polymer Synthesis
[0070] 1.2.1 Synthesis of 3-trimethylsilyl-prop-2-ynyl methacrylate (PMA)
[0071] According to Ladmiral V. and co-workers (16) 3-(trimethylsilyl)prop-2-yn-1-ol (2.31 ml, 15.6 mmol) and triethylamine (2.83 ml, 20.27 mmol) were dissolved in Et 2 O (20 ml) and cooled to −20° C. A solution of methacryloyl chloride (1.81 ml, 18.56 mmol) in Et 2 O (10 ml) was added drop wise over 1 hour. The mixture was stirred at −20° C. for 30 minutes and then overnight at room temperature. Ammonium salts were removed by filtration and the volatiles were removed under reduced pressure. The yellow oil residue was purified by flash chromatography (EtP:Et 2 O=50:1, Rf=0.39) (2.48 g, 12.64 mmol, Yield 81%).
[0072] 1 H-NMR (400 MHz, CDCl 3 ): δ=0.18 (s, 9H, Si(CH 3 ) 3 ); 1.97 (m, 3H, CH 3 C═CH 2 ); 4.76 (s, 2H, OCH 2 ); 5.62 (m, 1H, C═CHH); 6.17 (m, 1H, C═CHH).
[0000] 1.2.2 Synthesis of copoly(N,N-dimethylacrylamide (DMA)-3-trimethylsilyl-prop-2-ynyl methacrylate (PMA)-3-(Trimethoxysilyl)propyl methacrylate (MAPS)).
[0073] The polymer was synthesized via a random radical polymerization in anhydrous tetrahydrofuran with a 20% w/v total monomer concentration. The DMA was filtered on aluminium oxide to remove the inhibitor. The molar fraction of the monomers DMA, PMA and MAPS was 97:2:1.
[0074] The DMA and PMA monomers were dissolved in dried tetrahydrofuran (THF) in a round-bottom flask equipped with condenser, magnetic stirring. The solution was degassed by alternating argon purges with a vacuum connection, over a 10-min period. MAPS and α,α′-Azoisobutyronitrile (this latter at 2 mM final concentration) were added to the solution, which was then warmed to 65° C. and maintained at this temperature under a slightly positive pressure of argon for 2 h.
[0075] After the polymerization was completed, the solution was first diluted to 10% w/v with dry THF and the polymer precipitated by adding petroleum ether (10 times the reaction volume). The product, a white powder, was filtered on Buckner funnel and dried under vacuum at room temperature.
[0076] The protective trimethylsilyl groups were removed in water under basic condition, using K 2 CO 3 (9 mM) at pH 9. The reaction mixture was stirred at room temperature for 1 h, then the polymer was dialyzed, lyophilized and the white powder obtained was stored at −20° C.
1.2.3 Polymer Characterization by Gel Permeation Chromatography
[0077] The size of each polymer was characterized using Gel Permeation Chromatography in tandem with an UV-detector (A=214 nm).
[0078] A JASCO 880 PU liquid chromatography system, consisting of an isocratic pump to control mobile phase flow throughout the system connected to a JASCO UVIDEC-100-III UV detector. ChromNAV Chromatography Data System—JASCO was used to analyze the sequence of sample injection and to calculate the calibration curve of polyacrylamide standards.
[0079] The GPC setup consists of four Shodex aqueous GPC columns in series: OHpak SB-G (guard column), OHpak SB-804M HQ, OHpak SB-803 HQ, and OHpak SB-802.5 HQ. Each column is packed with a polyhydroxymethacrylate gel and connected in series with a decreasing exclusion limit. The columns were maintained at 40° C. throughout each run using a thermostated column compartment.
[0080] After the polymer sample is fractionated by GPC, the sample flows into a UV-detector. The molecular weight of the polymer was obtained by using a calibration curve.
[0081] Copoly(DMA-PMA-MAPS) sample was diluted using the GPC mobile phase (GPC buffer: 100 mM NaCl, 50 mM NaH 2 PO 4 , pH 3, 10% v/v Acetonitrile) to a concentration of 2.66 mg/ml and the sample was run three times through the GPC-UV system to test for reproducibility. Each run injected 20 μL of sample to be analyzed and the flow rate through the system was held at a constant 0.3 mL/min.
[0000] 1.3 Coating of Microarray Slides and Glass Substrates with Poly(DMA-PMA-MAPS)
[0082] Poly(DMA-PMA-MAPS) was dissolved in DI water to a final concentration of 2% w/v and then diluted 1:1 with an aqueous (NH 4 ) 2 SO 4 solution at 40% of saturation. The slides were immersed into the polymer solution for 30 minutes, rinsed in DI water, dried with nitrogen flow and then cured at 80° C. under vacuum for 15 minutes. Before the immersion the slide was pre-treated with oxygen plasma in a Plasma Cleaner from Harrick Plasma (Ithaca, N.Y., USA). The oxygen pressure was set to 1.2 Bar with a power of 29.6 W for 10 min.
1.4 Goniometry
[0083] Contact angle measurements were collected via the sessile drop method using a CAM200 instrument (KSV Ltd), which utilizes video capture and subsequent image analysis. Deionized water was used, and its purity was confirmed by correlating the measured surface tension based on the pendant drop shape to the literature values for pure water (72 mN/m at 25° C.).
1.5 Dual Polarization Interferometry (DPI)
[0084] Dual polarization interferometry (DPI) measurements were conducted using an Analight Bio 200 (Farfield Group, Manchester, UK) running Analight Explorer software. A silicon oxynitride AnaChip™ surface treated with oxygen plasma was used in this study. To measure the coating thickness, the chip was inserted into the fluidic compartment of an Analight Bio 200 and a polymer solution (1% w/v in a 20% saturated ammonium sulphate) was slowly introduced into the chip channels at a flow rate of 6 μl/min for 15 minutes. The flow was then stopped, and the solution was let in contact with the surface for 30 minutes before washing the channel with water, which was injected into the channel at a flow rate of 50 μl/min.
[0085] Before each experiment, a standard calibration procedure was performed using 80% (w/v) ethanol and MQ H 2 O solutions. The data were analyzed using Analight Explorer software to calculate the mass, the density and the thickness of the poly(DMA-PMA-MAPS) absorbed onto the surface.
1.6 Microarray Experiments
[0086] In the study of lectin-glycan interactions, an array of eight α-mannose derivatives carrying an azido linker was printed using a piezoelectric spotter (SciFlexArrayer S5, Scienion, Berlin Germany) on the surface of a polymer coated silicon slide. Four hundreds pL of each glycan was spotted at 10 μM or 50 μM concentration from an aqueous solution of Cu 2 SO 4 .5H 2 O (2.5 mM) and ascorbic acid (12.5 mM). Chemical structures and entries of the glycans 2-9 used in this study are reported in FIG. 1 . A α-mannoside (10) and β-galactoside (11) were used as positive and negative controls. Eleven replicates of the same glycan were spotted as shown in FIG. 2 a . The immobilization reaction took place during an overnight incubation in a humid chamber at room temperature. The printed slides were sequentially washed with PBS buffer for 10 minutes with DI water and dried by a nitrogen stream. The arrayed slides were then incubated with biotinylated α-mannose-binding lectin Concanavalin A (ConA) in the lectin binding buffer (LBB, 50 mM HEPES, pH 7.4, 5 mM MnCl 2 , 5 mM CaCl 2 ) in the presence of BSA (0.2 mg/ml). After 2 hours of incubation at room temperature on a lab shaker, the slides were washed 10 minutes in washing Buffer (0.05 M Tris/HCl pH9, 0.25 M NaCl, 0.05% v/v Tween 20), rinsed in DI water and dried by a nitrogen stream. A final incubation of 1 h with 2 μg/ml Cyanine3 labelled Streptavidin in PBS (Phosphate Saline Buffer) in a humid chamber at room temperature under static condition enabled the fluorescence detection of the surface bound ConA by means of a scanner (ProScanArray scanner from Perkin Elmer, Boston, Mass., USA) used at 70% of laser power and 60% of photomultiplier (PMT) gain ( FIG. 2 b ). The fluorescence intensities of 11 spot replicates were confirmed by three experiments that provided the same fluorescence intensities for each glycomimetic, with a standard deviation lower than 5%.
1.7 Determination of the Surface Equilibrium Constant by Fluorescence Experiments
[0087] The surface equilibrium constant, K D,surf for the interaction of eight different mannose derivatives with ConA was determined according to a method previously reported by Liang and co-workers (17). Several silicon/silicon oxide slides coated with poly(DMA-PMA-MAPS) were printed with 11 replicates of each glycan at 50 μM concentration to form an array of eight different α-mannose derivatives. Each slide was incubated for 2 hours with a given concentration of biotinylated ConcanavalinA (ConA) (from 47.2 pM to 9.43 nM) dissolved in LBB containing 0.2 mg/ml BSA.
[0088] After 1 hour of incubation with Cy-3 labeled Streptavidin (2 μg/ml) in PBS, the slides were scanned for fluorescence to evaluate the amount of ConA captured by the immobilized glycans. The Fluorescence intensities of 11 replicated spots were averaged.
[0089] The experimental conditions used during the incubation were optimized to ensure attainment of the equilibrium. The mean fluorescence intensities of the different glycans (spotted in 11 replicates) obtained from each single incubation was plotted against ConA concentration. The fluorescence values were fitted using OriginPro-8 that enables the calculation of K D,surf as EC50 for each glycan, depending on its affinity for ConA.
2 Results and Discussion
2.1 Design of the Polymer Structure and Substrate Selection
[0090] The inventor introduces a novel polymer named copoly (DMA-PMA-MAPS), obtained from the polymerization of N,N-dimethylacrylamide (DMA), 3-trimethylsilanyl-prop-2-yn methacrylate (PMA) and 3(trimethoxysilyl)-propylmethacrylate (MAPS) ( FIG. 3 ). The GPC-MALLS analysis of poly(DMA-PMA-MAPS) indicates that the polymer has a molecular weight (Mw) of 4.2×10 4 g/mol and polydispersity of 2.6. This new polymer is different from the polymer introduced by our group to form a hydrophilic 3D coating for microarray (18-20). The novelty of this work is the introduction of an alkyne moiety which allows binding azide-modified glycans by azide alkyne Huisgen cycloaddition using a Copper (Cu) catalyst at room temperature ( FIG. 4 ). Binding glycans to the surface via click chemistry offers a number of advantages (21-23) over classical nucleophilic reactions between amino modified probes and surface active esters. From the surface point of view, the stability of an alkyne group is far higher than that of an active ester, which typically is freshly prepared right before sugar immobilization. Additionally, when building arrays of natural glycans, the selectivity of the attachment point is guaranteed, as there are no natural glycans that contain azido functions. Replacement of the N-Acryloyloxysuccinimide monomer, the chemically reactive group of the prior art “parent” polymer with PMA does not alter either the self-adsorbing properties of the polymer or its physical characteristics. The coating is prepared by “dip and rinse”, by immersing the slide in an aqueous solution of the copolymer (10 mg/mL) at ambient temperature followed by washing with water. The coated substrates are then cured at 80° C. for 30 min. When glass-SiO 2 slides or Si—SiO 2 wafers are immersed in the copolymer solution for 30 minutes, ultrathin films of the polymer are generated. The rational behind replacing glass with Si/SiO 2 slides is to maximize fluorescence enhancement. As previously shown, the optical interference (OI) phenomenon induced by layers of well-defined thickness and different refractive index maximize photo-absorption of the dye molecules in the vicinity of the surface and enhance the light emitted towards the detector (24). These microarray slides display fluorescence intensity, at least, 5 times higher than that of standard glass slides.
2.2 Surface Characterization
2.2.1 Contact Angle Measurements
[0091] The contact angle was measured both before and immediately after the coating deposition to monitor and quantify changes of the surface hydrophilicity resulting from the presence of a surface polymer layer. The water contact angle could not be measured on an uncoated silicon chip after 10 minutes of plasma oxygen treatment because of its extremely high hydrophilicity (i.e. complete wetting). Thanks to this characteristic, the formation of a polymer coating is immediately evident because the water droplet contact angles increase on the coated surfaces from 0° to 33°±0.78° C. (the obtained contact angle value is the average of five measurements each on five different coated chips).
2.2.2 Dual Polarization Interferometry
[0092] The coating was also characterized using dual polarization interferometry (DPI), which is an optical surface analytical technique that provides multiparametric measurements of molecules on a surface to give information on the molecular dimension (layer thickness), packing (layer refractive index, density) and surface loading (mass)(25). From the DPI analysis it was possible to characterize the polymeric coating by obtaining values of thickness, mass and density (Table 1).
2.2.3 Polymer Binding Capacity
[0093] In order to assess the density of glycans bound to the polymer coated slide, a simple experiment was carried out based on the measurement of fluorescence after spotting, immobilization and washing of an azide-modified Cyanine-3 dye (1, FIG. 1 ). Following an approach described in reference 19, Cyanine 3 azide 1, was printed at concentrations ranging from 1 pM to 1 mM on copoly(DMA-PMA-NAS) coated silicon slides in 14 replicates. The slide was imaged at 543 nm with a fluorescence scanner (ProScanArray, PerkinElmer, Massachusetts, USA). After 12 hours of incubation in a dark humid chamber, the slides were washed with dimethylformamide (DMF) for 10 minutes to remove unbound molecules, dried under a nitrogen flow and imaged again to assess the binding efficiency. At a fixed laser power and photomultiplier gain (60% and 70% respectively) not all the spots could be visualized: 0.5 μM being the lowest detectable spotting concentration. Since the concentration (C) and the volume (V) of the Cy3 dye are known, the number of molecules covalently bound to the surface (Np) is the product of the number of Cy3 printed and the ratio of the pre-quench (Qpre) to post-quench (Qpost) spot intensities, where NA is Avogadro's number.
[0000]
Np
=
C
·
V
·
N
A
·
Qpost
Qpre
[0000] From the attachment density of the dye it was possible to estimate the distance between the molecules, which is representative of the distance between glycans.
The saturation density on the polymer was found to be 3 molecules/nm 2 . The density of bound molecule as a function of the spotted dye concentration are reported in FIG. 5 .
2.3.1 Microarray Experiments
[0094] The eight α-mannose derivatives 2-9 shown in FIG. 1 were spotted on the surface of a polymer coated Si/SiO 2 slide at 50 μM concentration. Alpha-mannose (10) and β-galactose (11) were used as positive and negative controls, respectively, whereas the Cy3 derivative 1 ( FIG. 1 ) was used as a reference to facilitate the imaging process. Concanavalin A (ConA) was chosen in this work, due to its well characterized affinity for Mannose and Glucose derivatives (26,27).
[0095] The surface-immobilized glycans, incubated with 100 ng/ml (0.943 nM) of biotinylated ConA and detected with Cy3-labelled streptavidin, show a variable degree of fluorescent intensity ( FIG. 2 ) depending on their affinity for ConA. The interaction between α-mannose derivatives and ConA was specific as confirmed by the lack of fluorescence on the spots of β-galactose (11), the negative control. The graph (b) of FIG. 2 reports the fluorescence intensity observed for different glycan spots. Except the ligand 5, all the mannosides of this study as well as the control 10 have similar affinities for ConA, as expected from their strong structural similarities. Differently, the ligand 5 does not seem to interact, possibly due to steric hindrance from the large, lipophilic amide groups. The analysis reported above provided only a qualitative estimate of the affinity between the α-mannose derivatives immobilized onto the surface and the selected lectin. In order to measure the equilibrium dissociation constant (K D ) of the interaction a more complex experiment is required. Nine slides were spotted with 50 μM and 10 μM aqueous solutions of 11 replicates of the glycomimetics 2-11 ( FIG. 1 ). The chips were incubated with ConA solutions of increasing concentration, from 47.2 pM up to 469.3 nM. By scanning the surface, a mean fluorescence value was obtained for each of the glycomimetic spot replicates. For each glycan, average values of fluorescence were plotted against ConA concentrations (logarithmic scale) and the curve was fitted as a sigmoidal/growth function. Typical curves of high (3) and low affinity (5) glycomimetics are shown in FIG. 6 . From these curves it was possible to extrapolate a value of EC50 (the half maximal Effective Concentration) for each molecule. EC50 refers to the ConA concentration at which half of the probes on the surface are occupied by the target. The values of EC50 reported in Table 2 represent the surface equilibrium constant K D,surf and provide a quantitative estimation of the affinity between the glycomimetics and the considered lectin, when the interaction occurs on a surface.
[0000]
TABLE 1
Thickness, mass and density of the poly(DMA-PMA-MAPS)
coating obtained from DPI analysis.
Thickness
Mass
Density
(nm)
(ng/mm 2 )
(g/cm 3 )
Poly-(DMA-PMA-
15.31 ± 3.21
1.98 ± 0.14
0.14 ± 0.04
MAPS)
[0000] TABLE 2 K D, surf values obtained for each glycomimetic printed at 50 μM and 10 μM concentrations. 50 μM 10 μM *K D, surf *K D, surf Glycomimetic (nM) (nM) 2 0.26 1.01 3 0.34 0.79 4 0.67 1.71 5 5.33 N/A 6 0.88 1.77 7 0.40 0.98 8 0.34 0.85 9 0.43 0.75 10 0.90 1.33
*The values of K D were determined by incubating the slides with ConA solutions ranging in concentration from 47.2 pM to 469.3 nM. Typical dose-response curves were measured and all the data obtained were fitted with OriginPro8 using a growth/sigmoidal function fixing the parameter p=1 and the parameter A1=0.
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ADDITIONAL EMBODIMENTS
[0123] Additional embodiments are provided including embodiments for gels and hydrogels and embodiments for multi-layers. See Working Examples 2 and 3 and supporting descriptions.
Gels and Hydrogels
[0124] Gels and hydrogels can be prepared by methods described herein. Gels and hydrogels are known in the art. They are cross-linked materials. Hydrogels are lightly crosslinked and swell extensively in water.
[0125] Many applications are possible with gels and hydrogels including many biochemical-oriented applications. One example of an application is a separation such as an electrophoretic separation, wherein hydrogels are used as sieving agents.
[0126] A number of hydrogels have been obtained by click chemistry reactions. They can be applied for a range of applications including, for example, drug delivery systems for the entrapment and release of pharmaceutically active proteins, and also as scaffolds for tissue engineering and repair. However, the use of click hydrogels as a sieving matrix in electrophoresis is not known.
[0127] In 2001, Sharpless has defined in Angewandte Chemie (Kolb et al., Angew. Chem. 2001, 113, 2056-2075 ; Angew. Chem. Int. Ed. 2001, 40, 2004-202) a set of criteria that a process should meet in the context of click chemistry:
“The reaction must be modular, wide in scope, give very high yields, generate only inoffensive byproducts that can be removed by nonchromatographic methods, and be stereospecific (but not necessarily enantioselective). The required process characteristics include simple reaction conditions (ideally, the process should be insensitive to oxygen and water), readily available starting materials and reagents, the use of no solvent or a solvent that is benign (such as water) or easily removed, and simple product isolation. Purification—if required—must be by nonchromatographic methods, such as crystallization or distillation, and the product must be stable under physiological conditions. [ . . . ] Click processes proceed rapidly to completion and also tend to be highly selective for a single product . . . ”. The click philosophy is based on the concepts of modularity and orthogonality: building blocks for a final target are made individually and subsequently assembled by means of click reactions. Over twenty reactions have been referred to as click reactions, one of such reactions is the Cu(I)-catalyzed cycloaddition.
[0129] In the gel and hydrogel embodiments, this type of reaction to form hydrogels can be carried out. One application is as sieving matrices for electrophoresis.
[0130] Some key elements of these embodiments include:
[0000] 1) the formation of a hydrogel for DNA electophoresis by click reaction of two suitable functionalities present separately on the two “gel forming” components. For the definition of click reaction in the context of polymers, see Angew. Chem. Int. Ed. 2011, 50, 60-62.
2) A hydrogel formed by two components where at least one of them is polymeric.
3) Optionally, both components are polymeric and multifunctional
4) Optionally, one is multifunctional and one is just functionalized at the two ends.
[0131] Copolymers described herein for click chemistry can be used to form hydrogels. For example, a first polymer can be functionalized with a click functionality such as alkyne groups. A second moiety such as a bifunctional agent or a bifunctional polymer can be functionalized with a complementary click functionality such as azide groups. The end groups of the polymer can be functionalized for the click chemistry. One or more of the components can be hydrophilic so as to provide for a hydrogel. Examples include poly(alkylene glycol) polymers and copolymers such as poly(ethylene glycol), poly(propylene glycol), and copolymers of same. The degree of crosslinking can adjusted to control the degree of swelling. One exemplary polymer component which has been used to demonstrate the concept of this embodiment is described herein. It is a copolymer of dimethylacrylamide (DMA), γ-methacryloxypropyltrimethoxy silane (MAPS) and a monomer bearing alkyne functionalities, 3-(trimethylsilylpropyne) methacrylate (TMS-PMA) that, upon deprotection of the alkyne, reacts with PEG functionalized by azide moiety at both ends via Cu(I)-catalyzed 1,3-dipolar cycloaddition reaction.
[0132] The monomer bearing alkyne functionalities can be made as described herein by copolymerization. Alternatively, post modification of a functional polymer can be carried out in which, one of the monomers of a copolymer is reacted with a bifunctional molecule that bears an alkyne group. As example of this approach is given by a polymer that contains a succinymidyl active ester (NAS) that reacts with propargylamine. The result is an alkyne-functionalized polymer.
[0133] There are several ways of forming the hydrogel, the one of the example is by a reaction of poly(DMA-PMA-MAPS), the alkyne-polymer, with a second polymer that bears azide groups such as, for example, polyoxyethylene bis(azide). The length of the PEG chain can vary in a wide interval without compromising its ability of cross-linking the chains of the alkyne polymer. The azido polymer can be different than PEG. Also, it can also have the same backbone of the alkyne polymer but contain azido functionalities pending from its backbone. Azido functionalities can be introduced directly in the polymerization step or be the result of a post modification process.
[0134] The Cu(I)-catalyzed 1,3-dipolar cycloaddition reaction is not the only type of click reaction that can be used to form the desired gel or hydrogel. Other examples are the reaction between thiol-functional polymer and maleimide-polymer, or thiol-polymer and alkyne-polymer catalyzed by UV in the presence of a photoinitiator, or any other type of reaction that satisfies the criteria for click chemistry.
[0135] The relative amounts of the two polymers participating in the click reaction can be adapted for the need. For example, the cross-link density and the hydrophobicity can be controlled by the ratio. For example, the weight ratio can vary from 99:1 to 1:99, or 95:5 to 5:95, or 90:10 to 10:90 with respect to either polymer. In some embodiments, for example, the majority component can be the alkyne copolymer, and the azido polymer can be the minority component. In other embodiments, the minority component can be the alkyne copolymer, and the azido polymer can be the majority component.
Example 2
[0136] FIG. 7 illustrates results from a slab gel separation of double stranded DNA fragments in a sieving matrix obtained by click chemistry reaction between copoly(DMA-MPA-MAPS) and O,O′-Bis(2-azidoethyl)polyethylene glycol catalyzed by 2.5 mM CuSO4, 12.5 mM ascorbic acid and 10 mM tris(3-hydroxypropyltriazolylmethyl)amine (THPTA). The gel was polymerized in 150 mM BisTris buffer at pH 7.2 at equimolar concentration of alkyne and azide groups. The concentration of the alkyne polymer was 10%. The DNA fragments (100 bp ladder) are stained with Sybr Green.
[0137] In example 2, copoly(DMA-NAS-MAPS) (the alkyne polymer) was synthesized as described above in Section 2.1. The polymer was dissolved at 10% w/v concentration in 150 mM BisTris-tricine buffer pH 7.2 containing 20× Sybr Green. To this solution poly(ethylene glycol) bisazide with an average Mn 1,100 from Aldrich, was added to a final concentration 10 mM (1.1% w/v). Catalysts, 2.5 mM CuSO 4 , 10 mM tris(3-hydroxypropyltriazolylmethyl)amine (THPTA), and 12.5 mM ascorbic acid were added and the gel was cast using a classical gel casting procedure. The solution becomes a gel in a time ranging from 30 minutes to two hours, depending on temperature. After the gel was formed, DNA (GeneRuler 100 bp) in the loading buffer (10 mM tris-HCl, sucrose and bromophenol blue) was loaded in the wells and the separation was run until the bromophenol blue contained in the DNA sample reached the end of the gel.
Multi-Layers
[0138] Another embodiment for the polymers described herein is for assembly of polymer multilayer films by click chemistry. The films can be ultrathin.
[0139] Polymer multilayers obtained by click chemistry are described in, for example, Such et al., J. Am. Chem. Soc. 2006, 128, 9318-9319. A variety of substrates can be used for building up films including inorganic substrates such as glass or silicon and organic substrates such as polymers.
[0140] Herein, a composition is provided where the first layer is made by a copolymer with three important ingredients that are, for example: a substituted acrylamide, preferentially DMA; a silane monomer, preferentially MAPS; and an alkyne monomer or a monomer that bears a functional group that, upon rection, is transformed into an alkyne. The role of DMA and of the silane polymer are outlined in patent application “SILANE COPOLYMERS AND USES THEREOF”, EU 11714266.1 and US 2013/0115382. The simultaneous presence of the surface interacting monomer, DMA, and the surface condensing monomer, MAPS, allows to form a stable covalent coating by a simple dip and rinse approach.
[0141] On the first layer, a second layer is formed by, for example, reaction of polyoxyethylene bis(azide) with the first layer. This latter polymer can be used in large excess so to quantitatively transform the alkyne groups on the surface in azido groups. In the specific case the azido group of one end of the PEG chain reacts with alkyne groups by Cu(I)-catalyzed cycloaddition whereas the second azide, at the other end, is available for reacting with alkyne groups of a third polymer so to form the third layer.
[0142] There is large flexibility on the choice of the chemical composition of the second and third layer, as, in this case the polymer attachment is ensured by its reaction with the layer underneath and not by the combination of physi- and chemi-sorption to the surface. Therefore, the silane condensing monomer is not required but it can optionally be present. The backbone of these polymers can be similar in composition to that of the first layer or different, the only requirement being the presence of azido or alkyne groups pending from the backbone of the polymers or located at their ends. In the formation of the third layer, polyoxyethylene bis(alkyne) can also be used.
[0143] The scope of the application is to protect a composition and its application to sensor surface modification with a functional layer so to allow covalent bonding of different ligands. The surface can be glass, silicon oxide, silicon nitrate, plastics, PDMS, gold, metal while the ligand can include a broad range of molecules such as biomolecules (proteins, DNA, peptides, glycans) or small organic molecules (drugs). Each of the three layers bind complementary functional groups. For instance, the layers 1 and 3 react with azido groups while the layer 2 reacts with alkyne groups. The coating can be made to contain the azide on the first layer, in this case, the second layer will be made to contain alkyne groups and the third, azido groups.
[0144] The rational behind building a multilayer structure in the context of a biosensor is to increase the distance between the rigid substrate and the biomolecule so to reduce constraints in the conformation of the biomolecule. In addition, the orthogonal character of click chemistry allows oriented immobilization of molecules that are regioselectively modified by functional groups that are not naturally present in their chemical structure.
[0145] The thickness of the layers can be adapted, and the number of the layers can be adapted. For example, film thickness for one layer can be, for example 1 nm to 10 nm. The number of layers can be, for example, 2-100 layers, or 2-10 layers.
Example 3
[0146] In this example, three layers of alkyne and azide polymers were alternated on the surface of a microarray slide.
[0147] First Layer: silicon slides with an oxide coating of 100 nm were coated with a thin layer of copoly(DMA-PMA-MAPS). The polymer was dissolved in DI water to a final concentration of 2% w/v and then diluted 1:1 with an aqueous (NH 4 )2SO 4 solution at 40% of saturation. The slides were immersed into the polymer solution for 30 minutes, rinsed in deionized water, dried with nitrogen flow and then cured at 80° C. under vacuum for 15 minutes. Before the immersion the slide was pre-treated with oxygen plasma in a Plasma Cleaner from Harrick Plasma (Ithaca, N.Y., USA). The oxygen pressure was set to 1.2 Bar with a power of 29.6 W for 10 minutes.
[0148] Second Layer: the coated slide was immersed in a solution of O,O′-Bis(2-azidoethyl)polyethylene glycol (4 mM) containing 2.5 mM CuSO 4 , 12.5 mM ascorbic acid and 10 mM tris(3-hydroxypropyltriazolylmethyl)amine (THPTA). The slide we left in this solution overnight and then rinsed extensively with water
[0149] Third layer: the slide with the two layers was immersed in a 1% w/v solution of copoly(DMA-PMA-MAPS) containing 2.5 mM CuSO4, 12.5 mM ascorbic acid and 10 mM tris(3-hydroxypropyltriazolylmethyl)amine (THPTA). The size of the PEG chain was 1000 Da. The slide was left overnight in this solution and then rinsed with water and dried extensively in vacuum at 80° C.
[0150] Samples of slides with the first, the second and the third layer were spotted with an azido-modified oligonucleotide (23 mer) from a solution containing the click catalysts (CuSO 4 , ascorbic acid, THPTA). After overnight incubation the slides were washed and incubated with a solution of the fluorescently labeled complementary oligonucleotide at a 1 uM concentration for 1 hour. The slides were then rinsed with the proper buffer and imaged with a fluorescence scanner. In FIG. 8 a the spots of the oligonucleotide are visible in the images of the alkyne modified substrates whereas no spots are detected on the second layer as the click reaction has converted the alkyne groups almost quantitatively. These experiments prove that layers of polymers with different functional groups form on the surface. In particular, the alkyne groups on the third layer result from a click chemistry reaction between azido and alkyne polymers. The spot average fluorescence intensity detected on first and third layer is quantified in the histogram of FIG. 8 b . The fluorescence for the second layer was negligible as no reaction occurred. | Fabrication of arrays, including glycan arrays, that combines the higher sensitivity of a layered Si—SiO 2 substrate with novel immobilization chemistry via a “click” reaction. The novel immobilization approach allows the oriented attachment of glycans on a “clickable” polymeric coating. The surface equilibrium dissociation constant (K D ) of Concanavalin A with eight synthetic glycans was determined using fluorescence microarray. The sensitivity provided by the novel microarray substrate enables the evaluation of the influence of the glycan surface density on surface K D values. The interaction of carbohydrates with a variety of biological targets, including antibodies, proteins, viruses and cells are of utmost importance in many aspects of biology. Glycan microarrays are increasingly used to determine the binding specificity of glycan-binding proteins. The click polymers can be prepared in different forms such as soluble polymers, hydrogels, and multi-layers. The polymers can be prepared directly by copolymerization or by copolymerization to form a pre-polymer which is then reacted to form the target polymer. Other uses include separations, including electrophoretic separations. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Patent Application Ser. No. 62/091,358 filed Dec. 12, 2014, U.S. Provisional Patent Application Ser. No. 62/052,981 filed Sep. 19, 2014, U.S. Provisional Patent Application Ser. No. 62/054,705 filed Sep. 24, 2014, U.S. Provisional Patent Application Ser. No. 62/056,936 filed Sep. 29, 2014, and U.S. Provisional Patent Application Ser. No. 62/060,403 filed Oct. 6, 2014, the entire disclosures of which are hereby incorporated herein by reference. This application is also related to U.S. patent application Ser. No. 14/495,702, U.S. Patent Application Publication Nos. 2012/0261349, 2013/0087504, and U.S. Pat. No. 8,361,384, the entire disclosures of which are hereby incorporated herein by reference.
FIELD
[0002] The invention pertains generally to systems and methods for treating water. More particularly, embodiments of the invention utilize systems that expose an oxygen containing gas to magnetic fields, catalysts, and/or a radiation source to form a treated gas, and then deliver the gas to water in order to treat the water.
BACKGROUND
[0003] Water used in various systems can accumulate undesirable content such as particulate matter, bacteria, algae, viruses, fungi, and pollutants. Examples of these water systems include cooling towers, evaporative coolers, swimming pools, fountains, sewage wastewater systems, water troughs for agricultural animals, agricultural runoff, and fisheries. If the undesirable content in these water systems is not treated, it can lead to broken devices, waterborne diseases, and other ill effects.
[0004] There are several existing options to treat water systems. For example, chlorination kills biological growth, desalination removes salt, and filtration removes particulate matter. A water system with undesirable content may bleed off water, and the water system is replenished with feed water that does not contain pollution, biological growth, etc. However, the use of chemicals or the constant replenishing of water can substantially increase costs associated with the maintenance of water quality.
[0005] Alternative water treatment options such as ultraviolet (UV) lamps can kill biological growth in water. However, UV lamps generally do not help with hyper-concentration and deposition of water-borne solids. Therefore, there is a need for a water treatment system that can function as a disinfectant and reduce the deposition of water-borne solids, while reducing the costs associated with such water treatment.
SUMMARY
[0006] Embodiments of the invention are directed to solving these and other problems and overcoming the disadvantages of the prior art. More particularly, embodiments of the invention provide for the maintenance and improvement of water quality using magnetic fields, catalysts, and radiation to increase oxygen radicals in oxygen containing gas or other gases, and then deliver the treated gas to a body of water or a water containing system.
[0007] In accordance with embodiments of the invention, oxygen containing gas is supplied to a water treatment device having a reaction chamber in which at least one magnet, at least one catalytic mount, and at least one UV lamp are disposed. The gas passes through the magnetic field, over the catalytic mount, and through the UV radiation to increase oxygen radicals in the gas, and to form a treated gas. The treated gas is delivered from the water treatment device and is placed in contact with a body of water or a water containing system. The treated gas can reduce particulate matter and disinfect the water.
[0008] In accordance with other embodiments of the invention, a mount may have a particular geometry that provides increased surface area for a catalytic material such as nickel. For example, the mount may have a plurality of vanes extending from a central body of the mount. These vanes may form a sweeping incline relative to a top and/or bottom surface of the mount. In addition, the mount may include additional elements that extend from the individual vanes to further increase the surface area of the mount. In various embodiments, the mount may actively or passively rotate to increase the amount of oxygen containing gas that contacts the surface area of the mount. The geometry of the mount may also serve other purposes beyond increased surface area. In some embodiments of the invention, the geometry of the mount provides a location that can receive other components, such as magnets.
[0009] In accordance with some embodiments of the invention, magnets may be used to create a magnetic field in a water treatment device. As described above, the mount may comprise a geometry that is adapted to receive magnets. The geometry may be a simple recess in the mount, or the geometry may be more complex such as a protrusion surrounded by an annular recess in the mount. The magnet may be disposed within a recess in the mount. The magnet may also be disposed about a radiation source, for example, a UV lamp. In other words, the magnet may be a ring shape that completely, or partially, encircles the radiation source. Further, more than one magnet may be associated with the mount.
[0010] In accordance with exemplary embodiments of the invention, a mount may be disposed at either end of the radiation source. The mounts may interconnect the radiation source to the water treatment device and/or be concentrically disposed about the radiation source. Once a mount and a magnet are disposed about the radiation source, the magnet may abut the mount such that the magnet is at least partially disposed in a recess of the mount. Further, the mount may have recesses on either side to accommodate magnets disposed on either side of the mount. Accordingly, the polarities of two magnets may be oriented such that the magnets are attracted to each other and are secured to the mount via magnetic attraction. In other embodiments, the polarities of two magnets may be oriented such that the magnets are repelled from each other. In these embodiments, the mount may include additional features such as a bayonet fitting to selectively interconnect the magnets to the mount. Various combinations of magnets, mounts, and radiation sources can be used to increase oxygen radicals in oxygen containing gas using magnetic fields, catalysts, and radiation simultaneously, nearly simultaneously, or in series.
[0011] Embodiments of the invention may be disposed in a number of support structures. These structures house the water treatment device, including the pump, the reaction chamber, and other components. In some embodiments the support structure is a cabinet where a user may open a door to access the components of the water treatment device. A pump inside of the cabinet draws oxygen containing gas from outside of the cabinet and expels treated gas outside of the cabinet through a conduit. In other embodiments, the water treatment device may only need to treat a body of water or a water containing system that is in a remote location for a short amount of time, and/or it may be desirable to change the location of the water treatment device periodically. Therefore, in some embodiments, the support structure is a trailer or other mobile support structure. It will be appreciated that the trailer may be cabinet-sized and towable behind a light truck or car. In other embodiments, the trailer may be a semi-truck trailer or an intermodal container.
[0012] Embodiments of the water treatment device may comprise any number of components alone or in combination. For instance, a water treatment device may have a radiation source with a mount-and-magnet combination disposed at either end of the lamp. In alternative embodiments, a mount-and-magnet combination may simply be disposed at midpoint along the length of the UV lamp. Further yet, a given water treatment device may comprise multiple radiation sources, and multiple water treatment devices may be arranged in parallel or in series to meet the requirements of the overall water treatment system.
[0013] One embodiment of the invention is a water treatment device, comprising a reaction chamber at least partially defining an enclosed volume, the reaction chamber having a first end and a second end, wherein an inlet is disposed at the first end of the reaction chamber and an outlet is disposed at the second end of the reaction chamber; a radiation source located within the enclosed volume, the radiation source having a longitudinal length substantially extending from proximate the first end of the reaction chamber to proximate the second end of the reaction chamber; a first mount disposed about the radiation source, the first mount having at least two vanes extending from the first mount, wherein at least a portion of a surface of the first mount comprises a catalyst; and a first magnet disposed about the radiation source and positioned adjacent to the first mount.
[0014] In some embodiments, gas enters the enclosed volume through the inlet, moves through a magnetic field generated by the first magnet, passes over the first mount and past the radiation source, and exits the enclosed volume through the outlet. In various embodiments, a second magnet is disposed about the radiation source and positioned adjacent to the first mount, the first magnet having a first polarity and the second magnet having a second polarity, wherein the polarities are oriented such that the first magnet and the second magnet are attracted to each other. In other embodiments, a second magnet is disposed about the radiation source and positioned adjacent to the first mount, the first magnet having a first polarity and the second magnet having a second polarity, wherein the polarities are oriented such that the first magnet and the second magnet are repelled from each other. In some embodiments, a second mount is disposed about the radiation source, the second mount having at least two vanes extending from the second mount, wherein at least a portion of a surface of the second mount comprises a catalyst; a third magnet disposed about the radiation source and positioned adjacent to the second mount; a fourth magnet disposed about the radiation source and positioned adjacent to the second mount, the third magnet having a third polarity and the fourth magnet having a fourth polarity, wherein the polarities are oriented such that the third magnet and the fourth magnet are attracted to each other.
[0015] In some embodiments of the invention, the first magnet fully encircles a circumference of the radiation source. In certain embodiments of the invention, at least two vanes form a vane angle with a bottom surface of the first mount, wherein the vane angle is between approximately 30° and 60°. In various embodiments, at least one element extends from each vane of the at least two vanes, wherein the at least one element and each vane of the at least two vanes forms a partially enclosed volume. In some embodiments, the first mount comprises an outer portion rotatably disposed about an inner portion, wherein the at least two vanes extend from the outer portion, and wherein the gas impinges the at least two vanes and causes the outer portion to rotate about the inner portion. In various embodiments, an electric motor operably interconnects to the first mount, wherein excitation of the electric motor causes the first mount to rotate about the radiation source. In some embodiments, the catalyst comprises at least one of nickel, CaNi 5 , NaTaO 3 :La, K 3 Ta 3 B 2 O 12 , (Ga 0.82 Zn 0.18 )(N 0.82 O 0.18 ), Pt/TiO 2 , cobalt, and bismuth.
[0016] In embodiment of the invention is a system for treating water, comprising a pump that draws in gas at a first pressure and expels the gas at a second pressure, wherein the second pressure is greater than the first pressure; a first conduit interconnected to the pump, the first conduit channeling the gas from the pump; a first treatment device having an inlet interconnected to the first conduit, the first treatment device comprising a reaction chamber at least partially defining an enclosed volume, the reaction chamber having a first end and a second end, wherein the inlet is disposed at the first end of the reaction chamber and an outlet is disposed at the second end of the treatment chamber; a radiation source located within the enclosed volume, the radiation source having a longitudinal length substantially extending from proximate the first end of the treatment chamber to proximate the second end of the reaction chamber; a first mount disposed about the radiation source, the first mount having at least two vanes extending from the first mount, wherein at least a portion of a surface of the first mount comprises a catalyst; and a first magnet disposed about the radiation source and positioned adjacent to the first mount.
[0017] In various embodiments of the invention, a second conduit interconnects to the outlet of the first treatment device, the second conduit channeling the gas from the first treatment device to a water source. In certain embodiments of the invention, a second mount disposed about the radiation source, the second mount having at least two vanes extending from the second mount, wherein at least a portion of a surface of the second mount comprises a catalyst; a third magnet disposed about the radiation source and positioned adjacent to the second mount; a fourth magnet disposed about the radiation source and positioned adjacent to the second mount, the third magnet having a third polarity and the fourth magnet having a fourth polarity, wherein the polarities are oriented such that the third magnet and the fourth magnet are attracted to each other. In various embodiments, a second treatment device has a second inlet interconnected to the first conduit, the second treatment device comprising a second reaction chamber, a second radiation source, a second catalyst, and a fifth magnet. In exemplary embodiments, a second magnet is disposed about the radiation source and positioned adjacent to the first mount, the first magnet having a first polarity and the second magnet having a second polarity, wherein the polarities are oriented such that the first magnet and the second magnet are attracted to each other. In other embodiments, a second magnet is disposed about the radiation source and positioned adjacent to the first mount, the first magnet having a first polarity and the second magnet having a second polarity, wherein the polarities are oriented such that the first magnet and the second magnet are repelled from each other. In some embodiments, the catalyst comprises at least one of nickel, CaNi 5 , NaTaO 3 :La, K 3 Ta 3 B 2 O 12 , (Ga 0.82 Zn 0.18 )(N 0.82 O 0.18 ), Pt/TiO 2 , cobalt, and bismuth.
[0018] Another embodiment of the invention is a water treatment device, comprising a support structure; a reaction chamber at least partially defining an enclosed volume, the reaction chamber having a first end and a second end, wherein an inlet is disposed at the first end of the reaction chamber and an outlet is disposed at the second end of the reaction chamber; a radiation source located within the enclosed volume, the radiation source having a longitudinal length that extends from proximate the first end of the reaction chamber to proximate the second end of the reaction chamber; a first mount disposed about the radiation source, the first mount having at least two vanes extending from the mount, the at least two vanes and a bottom surface of the first mount forming a first vane angle; a second mount disposed about the radiation source, the second mount having at least two vanes extending from the second mount, the at least two vanes and a bottom surface of the second mount forming a second vane angle; a plurality of magnets, wherein at least a first magnet in the plurality of magnets is a ring magnet that extends around at least a portion of the radiation source and is held by the first mount, and wherein at least a second magnet in the plurality of magnets is a ring magnet that extends around a second portion of the radiation source and is held by the second mount; and wherein gas enters the enclosed volume through the inlet, passes over the first mount, moves past the radiation source, passes over the second mount, and exits the enclosed volume through the outlet.
[0019] Yet another embodiment of the invention is a method for treating water, comprising providing a reaction chamber at least partially defining an enclosed volume, the reaction chamber having a first end and a second end, wherein the inlet is disposed at the first end of the reaction chamber and an outlet is disposed at the second end of the treatment chamber; providing a radiation source located within the enclosed volume, the radiation source having a longitudinal length substantially extending from proximate the first end of the treatment chamber to proximate the second end of the reaction chamber; providing a first mount disposed about the radiation source, the first mount having at least two vanes extending from the first mount, wherein at least a portion of a surface of the first mount comprises a catalyst; providing a first magnet disposed about the radiation source and positioned adjacent to the first mount; supplying oxygen containing gas to the reaction chamber through the inlet; moving the gas through a magnetic field generated by the first magnet, over the first mount, and through radiation generated by the radiation source; and expelling the gas from the reaction chamber through the outlet.
[0020] Additional features and advantages of embodiments of the invention will become more readily apparent from the following description, particularly when taken together with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 depicts a water treatment system according to an embodiment of the invention;
[0022] FIG. 2 is a side cross-section view of components of a water treatment device according to an embodiment of the invention;
[0023] FIG. 3 is a side cross-section view of components of a water treatment device according to another embodiment of the invention;
[0024] FIG. 4 is a perspective view of a water treatment device housed in a trailer according to an embodiment of the invention;
[0025] FIG. 5 is an exploded view of a reaction chamber and associated components according to an embodiment of the invention;
[0026] FIG. 6 is a side cross-sectional view of a reaction chamber and associated components according to an embodiment of the invention;
[0027] FIG. 7 is a flowchart depicting aspects of a method for treating water according to an embodiment of the invention;
[0028] FIG. 8 is a perspective view of a catalyst mount according to an embodiment of the invention;
[0029] FIG. 9 is a perspective view of a catalyst mount according to an embodiment of the invention;
[0030] FIG. 10 is a perspective view of a catalyst mount according to an embodiment of the invention;
[0031] FIG. 11 is a perspective view of a catalyst mount according to an embodiment of the invention; and
[0032] FIG. 12 is a cross-sectional view of a catalyst mount according to an embodiment of the invention.
DETAILED DESCRIPTION
[0033] FIG. 1 shows a water treatment system 100 used to treat water 104 in a body of water or a water containing system. A water treatment device 108 is one component of the system 100 , and the water treatment device 108 is housed in or associated with a support structure 112 , which in this embodiment is a cabinet. The water treatment device 108 draws in an oxygen containing gas, such as ambient air, passes the gas through a reaction chamber to create a treated gas, and supplies the treated gas to an outlet conduit 116 . The oxygen containing gas may be subjected to magnetic fields, catalysts, and/or radiation in a reaction chamber of the water treatment device 108 to form the treated gas. The outlet conduit 116 supplies treated gas to an injection port 120 , which introduces the treated gas to a body of water 104 . In this example, the water 104 is in a swimming pool. However, it will be appreciated that the water treatment system 100 can supply treated gas to water 104 in any body of water or water containing system 124 .
[0034] Now referring to FIG. 2 , additional components of a water treatment system 100 incorporating a water treatment device 108 in accordance with embodiments of the invention are depicted. In this embodiment, the water treatment device 108 provides treated gas to a water containing system 124 that includes a branch circuit 128 through which water 104 is circulated in the direction of arrow 132 . More specifically, treated gas is supplied from the water treatment device 108 by an outlet conduit 116 . An injection port 120 is disposed at the end of the outlet conduit 116 , and the injection port 120 introduces treated gas to the branch circuit 128 of the water containing system 124 . In general, the water treatment device 108 can supply treated gas to any water 104 that benefits from increased oxygen radicals. Examples of water 104 that can be treated using embodiments of the invention include cooling tower water, recreational water, therapy water, architectural water, and agricultural water.
[0035] The water treatment device 108 includes a reaction chamber 136 that, as described in detail elsewhere herein, contains at least one radiation source, such as a UV lamp, at least one magnet, and/or at least one mount with a catalyst. Oxygen containing gas is introduced to an inlet 140 , for example, by a pump 144 or other source of pressurized gas. The inlet 140 leads to the reaction chamber 136 , and the pump 144 delivers oxygen containing gas under positive pressure to the reaction chamber 136 at a desired flow rate. For example, oxygen containing gas can be provided at a flow rate of equal to or greater than 28 liters per hour (L/hr). Flow rates of 300 L/hr or greater may be required for some applications. The pump 144 has a pump outlet 148 that may interconnect to a common supply conduit 152 . The pressurized gas moves through the common supply conduit 152 , a solenoid 156 , and a supply conduit 160 before reaching the inlet 140 of the reaction chamber 136 . After exposure to the radiation, the magnetic field, and/or the mount with a catalyst, the oxygen containing gas exits the reaction chamber 136 through an outlet 164 as a treated gas, and is introduced to the water 104 in the water containing system 124 .
[0036] The water treatment device 108 also includes various electronic components. For example, a ballast 168 may supply a controlled current to the radiation source within the reaction chamber 136 . In addition, one or more controller boards 172 may be provided. A controller board 172 can include a processor and associated memory to execute software or firmware to control aspects of the operation of the water treatment device 108 . For example, operation of the pump 144 , the solenoid 156 , and the radiation source can be under the control of the controller board 172 . The controller board 172 can also receive control input, for example, from a user through an associated user input device 176 regarding the operation of the water treatment device 108 . Moreover, the controller board 172 can provide output to a user output device 180 concerning the operation of the water treatment device 108 . In an exemplary embodiment, the controller board 172 may comprise a controller device with an integrated processor and memory. Alternatively or in addition, the controller board 172 can include discrete digital logic devices and/or analog devices. Embodiments of a water treatment device 108 may include various gauges and/or indicator lamps 184 to provide an indication of the proper operation of the radiation source, pump, or other components. For example, a gauge can display the amount of current being drawn by one or more of the radiation sources. As a further example, a gauge or indicator lamp 184 can provide an indication of the pressure within the reaction chamber 136 , to provide information regarding the operation of the pump 144 . Further, a gauge or indicator lamp 184 may provide an indication of pressure at any point in the water treatment system 100 . Alternatively or in addition, the pressure within the reaction chamber 136 , or at any point in the system 100 , may be displayed on a pressure gauge 188 disposed on the exterior of the cabinet 112 .
[0037] Additional components may be optionally included in embodiments of the water treatment device 108 . For example, the common supply conduit 152 may include a radiator 192 to reduce the temperature of the pressurized gas. A cooling fan 196 may be disposed on an inner surface of the cabinet 112 to also reduce the temperature of the common supply conduit 152 or any other component of the water treatment device 108 . A filter 200 may be operably connected to the pump 144 or interior of the cabinet 112 to reduce particulate matter from the oxygen containing gas as it is drawn into the pump 144 .
[0038] The reaction chamber 136 can be generally cylindrical in shape, having an outer diameter and a length. In some embodiments, the reaction chamber 136 is comprised of UV resistant acrylonitrile butadiene styrene (ABS) plastic or polyvinyl chloride (PVC) material. In other embodiments, the reaction chamber 136 includes materials such as, but not limited to, metal, metal alloys, composites, and natural and synthetic polymers. It will be appreciated that in embodiment with multiple reaction chambers 136 , the reaction chambers 136 may not have identical outer diameters, lengths, or material compositions.
[0039] FIG. 3 shows a water treatment device 108 with two reaction chambers 136 a, 136 b. The water treatment device 108 can include any number of reaction chambers 136 , for example, to scale the water treatment device 108 such that an appropriate amount of treated gas can be provided to the water containing system 124 . The multiple reaction chambers 136 a, 136 b may be associated with multiple sets of components (e.g., a first ballast 168 a and a second ballast 168 a ). A pump 144 supplies pressurized gas to inlets 140 a, 140 b that correspond to each reaction chamber 136 a, 136 b, respectively. More particularly, pressurized gas moves through the common supply conduit 152 to a Y or T fitting 204 via a solenoid valve 156 . First 160 a and second 160 b supply conduits are interconnected to the first 140 a and second 140 b inlets of the reaction chambers 136 a and 136 b, respectively. In accordance with embodiments of the invention, the pump 144 draws oxygen containing gas from the ambient environment, and provides a pressurized supply of such gas to the reaction chambers 136 a, 136 b. The solenoid valve 156 allows the enclosed volumes of the reaction chambers 136 a, 136 b to be sealed off while the pump 144 is not supplying pressurized gas, for example, as a result of a planned or inadvertent shutdown of the pump 144 , to prevent a backflow of water into the water treatment device 108 .
[0040] Each reaction chamber 136 a, 136 b includes an outlet 164 a, 164 b. Each outlet 164 a, 164 b can be interconnected to a corresponding outlet conduit 116 a or 116 b. The outlet conduits 116 a or 116 b are in turn interconnected to a common outlet conduit 208 by a Y or T fitting 212 . The common outlet conduit 208 is interconnected to the branch circuit 128 at an injection port 120 . Accordingly, treated gas that has passed through reaction chambers 136 a, 136 b is supplied to the water 104 within the branch circuit 128 via the injection port 120 . In accordance with at least some embodiments, the injection port 120 can comprise a simple T fitting, a bubbler, a venturi, or the like. Alternatively or in addition, the injection port 120 can incorporate or be associated with a one-way valve that allows treated gas to enter the flow of water 104 , but to prevent that water 104 from entering the outlet conduit 208 . Moreover, the injection port 120 can also incorporate or be associated with a viewing port, for example, to allow maintenance personnel to confirm operation of the device by inspection.
[0041] A water treatment device 108 can incorporate more than two reaction chambers 136 through appropriate interconnections of the inlets 140 and outlets 164 of multiple chambers to the pump 144 and the injection port 120 , respectively. Multiple reaction chambers 136 may also be arranged in series. In accordance with still other embodiments, a water treatment device 108 can be provided with multiple reaction chambers 136 in which less than all of the reaction chambers 136 are operated. For example, additional reaction chambers 136 can be incorporated as spares, and can be interconnected to the pump 144 and the injection port 120 selectively, for example, after a failure of another one of the reaction chambers 136 . In accordance with still other embodiments, a water treatment device 108 with multiple reaction chambers 136 can be provided in which all of the included reaction chambers 136 are interconnected to the pump 144 and to the injection port 120 , but in which a selected number of radiation sources associated with reaction chambers 136 are operated at any particular point in time. Such embodiments permit larger amounts of treated gas to be supplied to the injection port 120 when required, by operating all or a greater number of the reaction chambers 136 , for example, upon startup of the water treatment device 108 or when aggressive treatment of the water 104 within the water treatment system 100 is desired. When a steady state or when aggressive treatment of the water 104 is not otherwise required, at least some of the radiation sources can be powered off to conserve electrical power.
[0042] Now referring to FIG. 4 , a water treatment device 108 that utilizes a trailer 216 for a support structure 112 is illustrated. Previous embodiments depict the support structure 112 as a cabinet. However, treatment of a body of water or a water containing system 124 may only be a temporary arrangement, and it may be necessary to periodically move the water treatment device 108 to different locations. As for other examples, the treatment of the water 104 within a water containing system 124 may be at a remote location, or it may simply be more convenient to provide a water treatment device 108 as a portable system. Therefore, in some embodiments, a water treatment device 108 as disclosed herein utilizes a trailer 216 , sled or other easily moveable assembly for a support structure 112 to provide a portable and/or easily deployed water treatment system 100 . The trailer 216 may be similarly sized as a semi-truck trailer or an intermodal container. In other embodiments, the trailer 216 is similarly sized as cabinet embodiments but includes components such as axles, wheels, hitches, etc. to achieve the desired mobility.
[0043] The trailer 216 comprises many or all of the same components as the cabinets described elsewhere herein. In FIG. 4 , the water treatment device 108 comprises an intake 220 through which oxygen containing gas in the ambient air is drawn from the ambient environment into a pump 144 . The intake 220 may comprise components such as a filter to improve the reliability of the various components within the water treatment device 108 by reducing the particulate matter from the oxygen containing gas. The pump 144 pressurizes the oxygen containing gas, which then moves into a supply conduit 160 and then into a reaction chamber 136 via an inlet 140 . The oxygen containing gas is subjected to a magnetic field, a catalyst, and/or radiation in the reaction chamber 136 . Since the trailer 216 allows for larger scale water treatment devices 108 , the reaction chamber 136 may include a number of lamps. For example, embodiments may include 90 UV lamps. Treated gas exits the reaction chamber 136 via an outlet 164 and into an outlet conduit 116 where the treated gas can be delivered to a body of water or a water containing system.
[0044] The trailer 216 also comprises other components. For example, the trailer 216 depicted in FIG. 4 comprises a door 224 to allow access inside of the trailer 216 for maintenance and other functions. The trailer 216 also comprises vents 228 that allow for the movement of air between the interior and exterior of the trailer. The vents 228 may be coupled with air blowers to provide an increased movement of air, for example, for cooling and/or the supply of oxygen containing gas to the water treatment device 108 .
[0045] FIGS. 5 and 6 are detailed views of components of a reaction chamber 136 in accordance with embodiments of the invention. In particular, FIG. 5 is an exploded view of an example reaction chamber 136 , and FIG. 6 is a cross-sectional view of the reaction chamber 136 of FIG. 5 . Referring to both FIGS. 5 and 6 , the reaction chamber 136 comprises a first end cap 232 , a chamber enclosure 236 , and a second end cap 240 . Oxygen containing gas enters the first end cap 232 through an inlet 140 . The gas flows through an enclosed volume 244 at least partially defined by the chamber enclosure 236 , the first end cap 232 , and the second end cap 240 , and then exits through an outlet 164 , which is disposed in the second end cap 240 .
[0046] The chamber enclosure 236 depicted in FIGS. 5 and 6 has a first end and a second end. The first end cap 232 is selectively interconnected to the chamber enclosure's 236 first end, and the second end cap 240 is selectively interconnected to the chamber enclosure's 236 second end. The selective interconnection between these components may be a screw fitting, a latching fitting, a snap fitting, or any other fitting that non-permanently joins two components. In other embodiments, one or both of the first end cap 232 and the second end cap 240 may be permanently joined with the chamber enclosure 236 . Alternatively, the first end cap 232 , second end cap 240 , and the chamber enclosure 236 may be milled from a single piece of material or otherwise formed as a unitary component.
[0047] The first end cap 232 has a conduit aperture 248 for a power conduit 252 to provide power to components located within the enclosed volume 244 of the reaction chamber 136 from an external power source. The power conduit 252 may be any power conduit 252 commonly known in the art. In various embodiments, the power conduit 252 may not require the conduit aperture 248 in the first end cap 232 . For example, the power conduit 252 may utilize coupled inductors to transmit power wirelessly. As another example, the power conduit 252 may comprise or be connected to an electrical socket or connector 256 that is connectible from outside of the enclosed volume 244 .
[0048] The power conduit 252 can pass through the first end cap 232 and can be operably interconnected to an electrical socket 256 . A radiation source 260 such as a UV lamp is selectively interconnected to the electrical socket 256 such that the power conduit 252 supplies power to the radiation source 260 . Wiring of electrically powered components such as the ballast, pump, and radiation source is not necessarily shown in the figures. However, it will be appreciated that the ballast is wired to the radiation source 260 , and that the water treatment device is electrically coupled to a source of electric power in order to operate. Typical electrical coupling includes, but is not limited to, plugging into an electrical outlet or hard-wiring.
[0049] The radiation source 260 , in some embodiments, can produce UV radiation in a range between approximately 40 nm and 400 nm, wherein “approximately” implies a variation up to +/−10%. For example, the radiation source 260 can comprise a low pressure mercury lamp that produces light at germicidal (e.g., about 254 nm) and ozone producing (e.g., about 185 nm) wavelengths. In at least some embodiments, the radiation source 260 is in the form of a longitudinal tube with first and second ends associated with first and second mounts 264 , 268 , respectively. The radiation source 260 can be a single ended device in which electrical contacts are provided at one end, or a double ended design, in which electrical contacts are provided at each end.
[0050] In some embodiments, the inlet 140 is coaxial with the radiation source 260 . In other embodiments, the inlet 140 is not coaxial with the radiation source 260 . The distance between the axis of the radiation source 260 and an axis of the inlet 140 is the inlet offset. The outlet 164 may be coaxial with the radiation source 260 , or the outlet 164 may comprise an outlet offset similar to the inlet offset described herein.
[0051] In the example embodiment of FIGS. 5 and 6 , a first mount 264 is adjacent a first end of the radiation source 260 that is selectively interconnected to or that locks to the electrical socket 256 , and a second mount 268 is disposed adjacent a second end of the radiation source 260 where the radiation source 260 has electrical contacts at each end so the second mount 268 may also be associated with the electrical socket 256 . In some embodiments, one or both of the first mount 264 and the second mount 268 can be nickel plated. The nickel plated first 264 and second 268 mounts function as a catalyst, more particularly a catalyst for forming oxygen radicals. In embodiments of the water treatment device 108 having multiple radiation sources 260 within a reaction chamber 136 , multiple pairs of first and second mounts 264 , 268 can be provided, and/or each pair of mounts 264 , 268 can be associated with multiple radiation sources 260 .
[0052] The reaction chamber 136 can also include one or more magnets. A first magnet 272 and a second magnet 276 may be disposed about, adjacent, or within the first mount 264 and have their polarities oriented such that the magnets 272 , 276 are attracted to each other. Similarly, a third magnet 280 and a fourth magnet 284 may be disposed about, adjacent, or within the second mount 268 and have their polarities oriented such that the magnets 280 , 284 are attracted to each other. As a result, magnetic fields that traverse at least some or a substantial portion of the enclosed volume 244 of the reaction chamber 136 are created. Accordingly, oxygen containing gas introduced at the inlet 140 is passed through one or more magnetic fields, as well as being exposed to electromagnetic radiation from the radiation source 260 . In accordance with alternative embodiments, the first and second magnets 272 , 276 can be arranged such that they repel one another, and the third and fourth magnets 280 , 284 can be arranged such that they repel one another. The magnets can comprise permanent magnets, including but not limited to high strength permanent magnets such as neodymium (Neodymium-Iron-Boron) grade N52. Alternatively or in addition, the magnets can comprise electromagnets. In accordance with still other embodiments, magnets can be located outside of the reaction chamber 136 , but positioned such that the magnetic field or fields produced by the magnets intersect gas that will be provided to the water.
[0053] FIG. 7 depicts a process 288 for treating water in accordance with some embodiments of the invention. In step 292 , oxygen containing gas is pumped to a reaction chamber 136 . The gas can be derived from any source such as, without limitation, the surrounding atmosphere, a compressor, an air pump, or a gas cylinder containing pressurized air to name a few. In some configurations, the gas can comprise an oxygen fortified air or a super-atmospheric oxygen gas stream. Oxygen fortified air generally refers to a gas stream containing more than about 21.1% oxygen (O 2 ) (according to the 1976 Standard Atmosphere) and nitrogen (N 2 ), argon (Ar) and carbon dioxide (CO 2 ) in volume ratio of about 78:1:0.04. At least some of the oxygen contained in the oxygen fortified air can be derived from an oxygen concentrator, oxygen-generator, and/or oxygen source (such as without limitation, bottled oxygen gas or liquid oxygen source). A super-atmospheric oxygen gas stream generally refers a gas stream having a partial pressure of oxygen greater than the ambient oxygen partial pressure. The super-atmospheric oxygen gas stream may or may contain one or more of nitrogen, argon and carbon dioxide and may have a nitrogen:argon:carbon dioxide volume ratio of about 78:1:0.04.
[0054] Next, in step 296 , the oxygen containing gas passes through a magnetic field generated by a first pair of magnets. The magnets may be permanent magnets, but in some configurations can be electromagnets. In some embodiments of the invention, the magnets in the first pair of magnets are oriented such that the magnets are attracted to each other. In yet further embodiments, the magnets in the first pair of magnets are oriented such that the magnets are attracted to each other. In alternative embodiments, magnets are arranged to the form a linear array with each magnet in the array repelling its nearest neighbors. Stated another way, like magnetic polls positioned adjacent to one another, such as for example (NS) (SN) (NS) (SN).
[0055] In step 300 the gas passes over a first catalytic mount, through radiation, and over a second catalytic mount. Embodiments of the invention may comprise one or more mounts to increase the production of oxygen radicals, for example ozone. The mounts have a surface area at least partially comprising a catalyst such as nickel to promote the production of oxygen radicals. As discussed in greater detail below, the geometry of the mounts can enhance the catalytic effect. In some embodiments, the electromagnetic radiation is UV radiation, which can be derived from any process and/or device generating UV radiation such as UV lamps. The gas may absorb at least some the UV radiation to form oxygen radicals. In some configurations, the gas is contacted with the UV radiation in the presence of a magnetic field. In still other embodiments, the gas is contact with the UV radiation in the presence of a magnetic field and in the presence of a catalyst. The UV radiation may comprise radiation having a wavelength of about 185 nm, about 254 nm, or a mixture of 185 and 254 nm wavelengths. As used herein, even lasers and diodes can emit radiation having spectral peaks, although the spectrum or spectrums of radiation may be very narrow. It will be appreciated that even radiation referred to as monochromatic usually emits wavelengths across a spectrum, albeit a very narrow one. Where an electromagnetic radiation source is described as emitting radiation of a specific wavelength or wavelengths, is should be understood that the specific wavelength or wavelengths is considered a spectral peak for the purposes of this specification and appended claims.
[0056] The gas also passes over or past a second catalytic mount in step 300 . Like the first catalytic mount, the second catalytic mount is at least partially coated or plated with a catalyst such as nickel. However, the gas's composition may change as it passes through the reaction chamber. Therefore, in some embodiments, it is advantageous to have a second catalytic mount with a different geometry, different type of catalyst, different area coated or plated with the catalyst, etc. to optimize production of oxygen radicals in the presence of a different gas composition. It will be appreciated that the two catalysts in this embodiment may also be identical.
[0057] In step 304 , the gas passes through a second magnetic field generated by a second pair of magnets. In some embodiments, the second pair of magnets is functionally identical to the first pair of magnets. As noted above, however, in some embodiments in may be advantageous to have a second pair of magnets that are different than the first pair of magnets because the gas may change in composition as in steps 296 and 300 . Therefore, weaker magnets, stronger magnets, magnets in different combinations, magnets in different locations, etc. may be advantageous. The treated gas exits the reaction chamber into the outlet conduits.
[0058] In step 308 , the treated gas moves through the outlet conduits and is introduced to a body of water or a water containing system. In some configurations, the water has a first concentration of bacteria and the treated water has a second concentration of bacteria. In some embodiments, the second concentration is no more than the first concentration.
[0059] FIGS. 8-12 depict some embodiments of a catalyst plated or coated mount 264 with a shape and surface composition that enhances the production of oxygen radicals such as ozone. For example, the catalyst may be nickel. The mount 264 has a central body 312 surrounded by first and second vanes 316 , 320 and first and second elements 324 , 328 . The central body 312 defines a partially enclosed volume that is generally cylindrical in shape and has an inner diameter. The radiation source 260 , or other electromagnetic source, is configured to pass through the partially enclosed volume such that the mount 264 is disposed about the radiation source 260 .
[0060] A first recess 332 is disposed on one end of the central body 312 , and a second recess 336 is disposed on the other end of the central body 312 . These recesses 332 , 336 have a larger inner diameter than the portion of the central body 312 that partially defines the enclosed volume. The magnets 272 , 276 , 280 , 284 (shown in FIGS. 5 and 6 ) are configured to be at least partially disposed in the recesses 332 , 336 in some embodiments. The magnets 272 , 276 , 280 , 284 are ring shaped so that the magnets 272 , 276 , 280 , 284 and the mount 264 may be disposed about the radiation source 260 . Then the magnets 272 , 276 , 280 , 284 may be disposed in the recesses 332 , 336 and abut the central body 312 of the mount 264 .
[0061] The magnets 272 , 276 , 280 , 284 may be arranged in two pairs, and magnets may be disposed on either side of the mount 264 . For example, the first and second magnets 272 , 276 may be disposed on either side of the mount 264 such that the first magnet is at least partially disposed within the first recess 332 , and the second magnet is at least partially disposed within the second recess 336 . Furthermore, the first and second magnets 272 , 276 may have their polarities oriented such that the magnets 272 , 276 are attracted to each other, and thus the first and second magnets 272 , 276 are secured to the mount 264 via magnetic attraction. In alternative embodiments, the first and second magnets 272 , 276 may have their polarities oriented such that the magnets 272 , 276 are repelled from each other. In these embodiments, the magnets 272 , 276 may be selectively interconnected to the mount 264 via, e.g., a screw fitting, a bayonet fitting, a latch, etc., to resist the repulsion force.
[0062] Next, first and second vanes 316 , 320 extend from the outer surface of the central body 312 . As shown in FIG. 8 , the vanes 316 , 320 form a sweeping incline relative to a horizontal or lateral plane. In some embodiments of the invention, the inclined surface of the vanes 316 , 320 allow the mount 264 to rotate about or relative to the radiation source 260 . For example, the mount 264 may be disposed about a bearing device at an end of the radiation source 260 that allows the mount 264 to rotate freely about an axis corresponding to a longitudinal axis of the radiation source 260 . Thus, when gas enters the reaction chamber through the inlet, the gas impinges upon the inclined surface of one or more vanes 316 , 320 which causes the mount 264 to rotate. The rotation aids in mixing the gas of the reaction chamber to more evenly distribute the oxygen radicals. Further, the mixing aspect of this embodiment allows more gas to interact with the catalytic area of the mount 264 , which increases the production of oxygen radicals.
[0063] In some embodiments, the mount 264 may comprise electric contacts to energize the radiation source 260 . In further embodiments, the mount 264 uses electric energy to mix the gas in the reaction chamber 136 . The mount 264 may be a two piece design where a bearing device and an electric motor allow an outer concentric portion of the mount 264 to actively rotate about an inner portion of the mount 264 . This is opposed to other passive embodiments that rely on gas impingement or thermal convection to rotate the mount 264 . As the outer portion rotates, the mount 264 arms agitate the gas inside of the reaction chamber 136 , which increases the amount of the gas that contacts the mount 264 and is exposed to the radiation source 260 .
[0064] First and second elements 324 , 328 extend from the first and second vanes 316 , 320 , respectively, and the first and second elements 324 , 328 form partially enclosed volumes with the first and second vanes 316 , 320 , respectively. The additional elements 324 , 328 provide more surface area for the mount 264 to interact with the gas, and thus increase production of oxygen radicals.
[0065] The surface composition of the mount 264 can enhance the production of oxygen radicals in the gas. As mentioned above, the mounts 264 may be comprised of, or coated with, a material such as nickel. Other catalytic materials include, but are not limited to, CaNi 5 , NaTaO 3 :La, K 3 Ta 3 B 2 O 12 , (Ga 0.82 Zn 0.18 )(N 0.82 O 0.18 ), Pt/TiO 2 , Cobalt-based systems, and Bismuth-based systems. In addition to the mount 264 , the reaction chamber 136 or other components of the system 100 may be comprised of, or coated with, a catalytic material to induce the production of the oxygen radicals in the gas.
[0066] It will be appreciated that a variety of shapes can be used to increase the surface area of the mount 264 and surface composition that is exposed to gas in the reaction chamber. For example, more than two vanes may be disposed about the central body 312 of the mount 264 where each additional vane increases the surface area of the mount 264 . In addition, finned surfaces may be employed to further increase the surface area of the mount 264 . Fins may be arrayed in a simple grid-like fashion with longitudinal rows and lateral rows oriented perpendicular to each other, in a more complex three-dimensional pattern, or any other pattern that is commonly known in the art.
[0067] FIG. 9 illustrates an embodiment of the mount 264 with four vanes 316 , 320 , 340 , 344 disposed about the central body 312 . The inner surface of each vane is connected to the central body 312 along the entire length of the vane. The ends of the vanes 316 , 320 , 340 , 344 terminate at the top and bottom surface of the central body 312 . However, it will be appreciated that the ends of the vanes 316 , 320 , 340 , 344 may run shorter or longer than the surfaces of the central body 312 .
[0068] The vanes 316 , 320 , 340 , 344 in FIG. 9 generally have an angle relative to the central body 312 of the mount 264 . FIG. 9 also shows that when viewed along a longitudinal axis of the mount 264 , the vanes slightly overlap each other such that there are no gaps between the vanes. It will be appreciated that other embodiments may comprise gaps between the vanes when viewed along a longitudinal axis of the mount 264 .
[0069] FIGS. 10-12 show other embodiments of a mount 264 . FIG. 10 shows a mount 264 with two vanes 316 , 320 that extend outward and curl around a central body 312 of the mount 264 in opposing directions. The vanes 316 , 320 in this embodiment are not inclined relative to a horizontal plane, a lateral plane, a top surface of the central body 312 , or a bottom surface of the central body 312 .
[0070] FIG. 11 shows a mount 264 that is taller in the longitudinal direction of the radiation source than the mount 264 depicted in FIG. 10 . This elongation of the mount 264 further increases its surface area, particularly in the direction of the gas flow. FIG. 11 also shows that the ends of the mount 264 vanes are not perpendicular to the top and/or bottom surfaces of the mount 264 . Instead, the ends of the vanes taper to a point, which exposes more surface area toward the radiation source for increased production of oxygen radicals.
[0071] FIG. 12 is a cross-section view of the mount 264 of FIG. 11 taken along a longitudinal plane. This cross-section view shows that the inner surfaces of the vanes also comprise a taper or angle that increases the surface area of the mount 264 that is exposed to the moving gas for increased production of oxygen radicals.
[0072] It will be appreciated that embodiments of the invention are not limited to particular dimensions. However, dimensions of some exemplary water treatment system components are provided. In some embodiments, the reaction chamber's outer diameter is between approximately 2.5 cm and 31 cm. In various embodiments, the reaction chamber's outer diameter is between approximately 3.5 cm and 9.0 cm. In a certain embodiment, the reaction chamber's outer diameter is approximately 3.8 cm, and in another embodiment, the reaction chamber's outer diameter is approximately 8.9 cm. Further, the reaction chamber's length is between approximately 30 cm and 178 cm. In various embodiments, the reaction chamber's length is between approximately 66 cm and 102 cm. In certain embodiments, the reaction chamber's length is approximately 66 cm, 76 cm, 91.5 cm, 96.5 cm, or 101.5 cm.
[0073] Exemplary arrangements or orientations of various components are also provided. In various embodiments, the inlet offset between the inlet to the reaction chamber and the radiation source is between approximately 0.25 cm and 30.5 cm. In other embodiments, the inlet offset is between approximately 0.5 cm and 15.5 cm. In certain embodiments, the inlet offset is between approximately 1 cm and 5.5 cm. In some embodiments, the inlet offset is approximately 1.2 cm.
[0074] In some embodiments, this vane angle between the vane and one of the top or bottom surface of the central body of the mount is between approximately 5° and 60°. In various embodiments, the vane angle is between approximately 15° and 45°. In some embodiments, the vane angle is approximately 30°. In other embodiments, this vane angle is between approximately 30° and 60° from the bottom surface of the mount 264 . In a further embodiment, the vane angle is approximately 45° from the bottom surface of the central body. In some embodiments, the vanes taper at a vane angle between approximately 30° and 60° from the bottom surface of the mount. In a further embodiment, the vane angle is approximately 45° from the bottom surface of the mount. In some embodiments, the inner surfaces of the vanes are angled between approximately 60° and 90° from the bottom surface of the mount. In a further embodiment, the inner surface is angled approximately 75° from the bottom surface of the mount.
[0075] In addition to exemplary dimensions and orientations, exemplary components are provided. As an example, without limitation, the pump 144 may be a Tetra Whisper® 150 aquarium air pump. In addition, a non-limiting example of a ring magnet is a 1.9 cm×1.3 cm×3.2 cm neodymium ring magnet. The ring magnets comprising each pair of magnets are placed about 0.6 cm apart with poles opposing each other. A magnetic field perpendicular to the lamp is generated by the opposing poles of each pair of magnets. Moreover, the magnetic field generated by each pair of magnets passes directly across the corona of the lamp positioned with the void of the ring magnets.
[0076] The neodymium magnets have a residual induction (Br) from about 12.9 to about 13.3 KGauss and about 1.29 to about 1.33 Tesla, a minimum coercive force from about 1.5 to about 12.4 K-Oersted and from about 915 to about 987 kA/m, a minimum intrinsic coercive force Hci from about 12 to about 25 K-Oersted and from about 955 to about 1,592 kA/M, and maximum energy product (BH) max from about 40 to about 43 MGOe and from about 318 to about 342 kJ/m3
[0077] In accordance with exemplary embodiments of the invention, a radiation source such as a UV lamp can produce UV radiation with multiple wavelengths in a water treatment device. The UV lamp may produce a first wavelength that is within a range of from about 178 nm to about 187 nm to produce oxygen radicals such as ozone gas, and the UV lamp may produce a second wavelength that is within a range from about 252 nm to about 256 nm, which is highly antimicrobial. The radiation source 260 may also be a G36T5VH/4P (manufactured by USHIO America, Inc., a subsidiary of USHIO Inc. of Japan) ozone producing quartz UV lamp, with a main spectral peak at approximately 253.7 nm and another spectral peak at approximately 185 nm. The G36T5VH/4P ozone producing quartz UV lamp is generally elongate and cylindrical, having a length of about 84 cm and a diameter of about 1.5 cm. It uses a universal B224PWUV-C ballast. The G36T5VH/4P lamp consumes approximately 40 watts power and emits approximately 14 watts power in the form of UV radiation.
[0078] Other embodiments comprise other radiation sources, including, but not limited to, other UV lamps, lasers, or diodes adapted to emit radiation in the UV range. Some embodiments do not require a ballast, or use a different ballast than the B224PWUV-C. Non-limiting examples of suitable lamps include arc, discharge (including noble gas, sodium vapor, mercury vapor, metal-halide vapor or xenon vapor), induction, plasma, low-pressure, high-pressure, incandescent and discharge lamps emitting UV radiation having suitable wavelengths. Examples of suitable lasers, without limitation, include gas, chemical, excimer, solid-state, fiber, photonic, semi-conductor, dye or free-electron laser operate in one of continuous or pulsed form. Furthermore, suitable diodes include without limitation are diamond, boron nitride, aluminum nitride, aluminum gallium nitride, and aluminum gallium, indium nitride.
[0079] In some embodiments, the radiation source or the magnets reside outside the reaction chamber. In these embodiments, the chamber enclosure 236 permits transmission of substantial amounts of radiation from the radiation source 260 into a reaction chamber 136 . For example, a glass tube comprising GE Type 214 fused quartz glass is an appropriate chamber enclosure 236 where the radiation source resides outside the reaction chamber 136 .
[0080] Moreover, the radiation source 260 can, in an exemplary embodiment, but without limitation, comprise a four pin single ended device with pins or electrical contacts. It will be appreciated that in a single-ended lamp, the power is supplied to an electrode or electrodes at one end of the radiation source 260 by wires that extend from the first end to the second end of the radiation source 260 . In accordance with a further example embodiment, the radiation source 260 can be a double ended device, with electrical contacts at each end. In accordance with still other embodiments, the radiation source 260 can comprise any source of radiation at the desired wavelength or wavelengths. For example, a radiation source 260 can comprise one or more lasers tuned or otherwise configured to output a desired wavelength or wavelengths.
[0081] Next, embodiments with exemplary performance results are provided. In at least some embodiments, the nickel plated mounts 264 , 268 can improve the efficiency of forming oxygen radicals by at least about 10%, more commonly by at least about 25%, or even more commonly by at least about 50%. Moreover, the nickel plated mounts 264 , 268 typically improve the effectiveness of the treated gas used to treat water by at least about 10%, more typically by at least about 25%, or even more typically by at least about 50%. Moisture (characterized as relative humidity “RH” in Table I below) in the gas can affect the catalytic process. The first 264 and second 268 mounts may be nickel plated by an electroless plating process. The nickel plating may be nickel phosphorous alloy having from about 4 to about 7 wt % phosphorous. The nickel plating has a thickness from about 7.62 micro meters to about 12.7 micro meters.
[0082] Table I below summarizes the improvement realized by moving the gas over a nickel plated mount in the reaction chamber. The scenarios where the mount was nickel plated realized an increase in production of oxygen radicals, as measured by an ozone meter. Furthermore, the level of water vapor in the gas can enhance the efficiency and effectiveness of the conversion of oxygen containing gas to treated gas with addition oxygen radicals.
[0000]
TABLE I
PPM Oxygen Radicals Produced*
Without Ni
Without Ni
With Ni
With Ni
Feed Gas
Catalyst
Catalyst
Catalyst
Catalyst
Liters/Min
(15% RH)
(40% RH)
(15% RH)
(40% RH)
5
14.2
14.3
16.9
18.8
10
12.3
12.6
14.4
17.2
15
9.1
9.1
10
10.7
20
5.4
5.4
6
6.3
*as measured by an ozone meter.
[0083] Embodiments of the invention comprise water treatment devices that utilize a magnetic field, a mount having a catalyst, radiation, and/or oxygen containing gas to produce gas that can be used to treat water, including but not limited to solute-laden water, highly alkaline water, and biologically contaminated water, or water that will likely become highly alkaline or biologically contaminated in the absence of treatment. An example of such water is cooling tower water. Other examples include, but are not limited to oil or gas well by-product water and other contaminated water generated as a by-product of an industrial process or processes. Embodiments of the invention are also effective at treating swimming pool water and spa or hot tub water, where the water treatment devices typically stabilize chlorine concentration, and reduce the need for chlorine in the water.
[0084] By use of the water treatment device, the pH of solute laden water such as cooling tower water can be modulated, and biological contamination is highly controlled without the use of, or with substantially reduced use of, chemical agents. Water treatment costs are therefore reduced by use of the water treatment device over chemical treatment alone. Embodiments of the invention effectively treat cooling tower water by preventing or eliminating biological contamination of the water, and by lowering pH about 0.2 units, or maintaining cooling tower water pH 0.2 units below what the pH would be if the cooling tower water were untreated.
[0085] Embodiments of the water treatment device disclosed herein can mitigate total alkalinity such that alkalinity does not concentrate as fast as calcium ions, water hardness, chloride ions, conductivity, or other indices of cycles of concentration. In a typical installation, total alkalinity is 50%-75% of expected based on cycles of concentration indicated by an increase in chloride ion concentration. The reduced alkalinity can be highly beneficial, with deposition of scale and other mineral deposits on cooling tower parts being greatly reduced or eliminated completely. Embodiments of the water treatment device disclosed herein can operate to decrease calcium concentration where the water treatment device is installed on a cooling water system that has incurred substantial mineral deposits. In many cases, the substantial mineral deposits can be substantially or completely eliminated. The substantial mineral deposits are typically eliminated within a year of installing the water treatment device.
[0086] In some embodiments, the water treatment device includes a glass media filter. The filter can remove or reduce suspended solids, including dead bacteria, and may help prevent infestation of water with Legionella bacteria.
[0087] In some embodiments, the water treated by the water treatment device is cooling tower water. The cooling tower water may be a re-circulated cooling tower water, typically referred to as a closed dry cooling tower water. While not wanting to be limited by example, the cooling tower water may be a component of an oil refinery, a petrochemical and/or other chemical plant, a power station or a heating, ventilation and air condition system. The water treatment device can be configured to introduce treated gas at any location in the cooling water system. The treated gas may be contacted with water that is injected in the cooling tower header line and/or side stream line interconnected to the cooling tower header line.
[0088] In some embodiments, the water treated by the water treatment device is one of recreational, therapy and architectural water. The recreational, therapy and/or architectural waters may comprise a re-circulating water system. Non-limiting examples of recreational waters include swimming pools, spas and hot tubs. Non-limiting examples of therapy pools include hydrotherapy pools, injury (such as, burn, skeletal, and/or muscular) recovery/rehab pools, low impact exercise pools and such. Architectural waters include without limitation water fountains, water walls, reflective pools and the like. The water re-circulating system for recreational, therapy and architectural waters typically include one or more of the following unit operations: balance tank unit; flocculation process; filtration unit; aeration unit; antimicrobial treatment unit; and sorbent treatment unit. The water treatment device can be configured to contact treated gas with the recreational, therapy and/or architectural water at any location in the re-circulating water system. The water treatment device can replace one or more of the unit operations, such as but not limited to the aeration and antimicrobial units.
[0089] In some embodiments, the water treated by the water treatment device is agricultural water. The water may contain an adjuvant being applied to animal and/or plant to treat the animal and/or plant. In some embodiments, the adjuvant is formulated with water treated by the water treatment device. In some embodiments, the water containing the adjuvant is treated by the water treatment device prior to being applied to the animal and/or plant.
[0090] The foregoing discussion of the invention has been presented for purposes of illustration and description. Further, the description is not intended to limit the invention to the form disclosed herein. Consequently, variations and modifications commensurate with the above teachings, within the skill or knowledge of the relevant art, are within the scope of the invention. The embodiments described hereinabove are further intended to explain the best mode presently known of practicing the invention and to enable others skilled in the art to utilize the invention in such or in other embodiments and with various modifications required by the particular application or use of the invention. It is intended that the appended claims be construed to include alternative embodiments to the extent permitted by the prior art. | A water treatment device for treating water in water systems such as cooling towers, evaporative coolers, swimming pools, fountains, sewage wastewater systems, water troughs for agricultural animals, agricultural runoff, and fisheries is described. The water treatment device utilizes a magnetic field, a catalyst, and ultraviolet (UV) radiation to produce a treated gas with increased oxygen radicals to treat a body of water. A mount disposed about a UV lamp may comprise the catalyst material or materials to increase the production of oxygen radicals. The resulting treated gas may be placed in contact with a body of water, for example, to reduce particulate build up, biological matter, and other pollutants. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to memo pad devices; and, more particularly, to a portable device holding a replaceable memo pad that can be transported between a phone booth and a vehicle.
2. Description of the Prior Art
Various types of memo pad holders are known in the art. Such holders typically have a spring biased grip for holding a pad and a place on the holder for retaining a writing instrument. Some such holders may have means, such as a magnet or suction cup, so the holder can be releasably attached to a supporting surface.
Although such devices are portable, and can be carried between home and vehicle, for example, they cannot be mounted temporarily in a phone booth or the like. They must be laid on a seat or shelf and use thereof is thus quite cumbersome.
There is thus a need for a memo pad holder which can be transported between a vehicle and a phone booth, mounted temporarily in both locations, yet provide a firm and steady writing surface.
SUMMARY OF THE INVENTION
It is an object of this invention to provide a portable memo pad holding device for a car and remote telephone.
It is a further object of this invention to provide such a device which has removable attachment means for removably and selectively attaching the device to a vehicle or cradle of a telephone.
These and other objects are preferably accomplished by providing a portable memo pad device which can be transported in a vehicle between the vehicle and a phone booth. The device includes a removable pad and a mount adapted to fit on the standard cradle of a telephone booth out in public in place of the transmitter-receiver. The mount also includes a suction cup for removably attaching the device to the dashboard or the like of a vehicle. Thus, the device can be moved back and forth between a vehicle and a remote telephone.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1, is a vertical elevational view of the device of the invention;
FIG. 2 is a side view of the device of FIG. 1;
FIG. 3 is a rear view of the device of FIG. 1;
FIG. 4 is a vertical elevational view of a conventional commercial telephone showing the device of FIGS. 1 to 3 mounted on the cradle of the telephone;
FIG. 5 is a side view of the mounted device of FIG. 4;
FIG. 6 is a front view taken along lines VI-VI of FIG. 5;
FIG. 7 is a view taken along lines VII-VII of FIG. 6;
FIG. 8 a view taken along lines VIII-VIII of FIG. 6;
FIG. 9 is a view similar to FIG. 8 showing a second position of the parts thereof; and
FIG. 10 is a view taken along lines X-X of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1 of the drawing, a portable memo pad holder device 10 is shown having a generally flat planar main body portion 11 with a resilient clip 12, having an integral grasping tab 13, mounted on body portion 11. As seen in FIG. 2, clip 12 is generally L-shaped having a short leg portion 14 integral with a flange member 15 (see also FIG. 1) mounted to body portion 11 or forming a portion thereof in any suitable manner. As is well known in the art, clip 12 is resiliently and integrally hinged to body portion 11 and, thus, by grasping tab 13, the longer leg portion 17 can be pulled away from body portion 11 so that a writing pad 18 of paper can be snapped thereunder and be removably retained therein.
As also seen particularly in FIG. 2, an elongated pen retaining tab 19 (see also FIG. 1) is provided integral with body portion 11 and extending away from body portion 11. Tab 19 is spaced from leg portion 14 a sufficient distance such that a pencil or pen (not shown) can be snapped therebetween and be retained therein until it is necessary to use the same as a writing instrument.
Main body portion 11 has an integral upper portion 20 having a plurality of circular cavities 21 to 23 therein, each cavity 21 to 23 being blocked off partially at the side by a flange portion (e.g., flange portions 24 to 26, respectively). As seen in FIG. 10, each cavity 21 to 23 has a spring 27 therein with a plurality of coins 28 between spring 27 and flange portion 26 (for example). Thus, cavities 21 to 23 vary in diameter, each receiving a different size coin therein, such as dimes in cavity 21, nickels in cavity 22 and quarters in cavity 23. The springs 27 bias the coins outwardly for easy removal. Of course, flange portions 24 to 26 serve to retain the coins in their respective cavities until removal.
As seen in FIG. 2, a support 29 is integral with the back of body portion 11 having a lower elongated portion 30 and an upper enlarged generally triangular portion 31. Portion 31 has a flat angled portion 32 (see also FIG. 3). As seen in FIG. 2, the angle of surface 32' is generally parallel to the angle of surface 36' of support 36 (e.g., about 45° with respect to the horizontal) so that, when in the position shown in FIG. 4, pad 18 is at a desired writing angle.
Support 29, along with pivotable support 36 (FIG. 1) serves to support device 10 on the conventional cradle 37 of a telephone 38 (FIG. 4). Thus, as seen in FIG. 1, support 36 is generally rectangular having an open generally rectangular area 39 for receiving therein the hook 39' (see particularly FIGS. 6 and 7) of the telephone 38, the hook 39 being free to move up and down. Support 36 also includes spaced enlarged portions 40, 41 (FIG. 1) at the top right and left side of support 36. Enlarged portion 40 has a groove 42 therein while enlarged portion 41 has a groove 43 therein. As seen in FIGS. 2 and 3, support 20 has an integral generally circular portion 61 with a spaced circular flange 62 (see also FIG. 1). Rectangular support 36 (FIG. 2) has a circular boss 63 rotatable between portion 61 and flange 62 with a lip portion 64 acting as a stop (FIG. 1) which abuts against support 20. As seen in FIG. 6, the right cradle portion 44 of cradle 37 is received in groove 43 whereas the left cradle portion 45 of cradle 37 is received in groove 43. As seen in FIG. 5, flat angled portion 32 abuts against the telephone 38 and serves to support device 10 so that pad 18 is in the angled position shown in FIGS. 4 and 5 for writing thereon. Thus, as seen in dotted lines in FIG. 1, support 36 moves from the cradle support or solid line position to the dotted line or stored position 36" (i.e., when mounted to a telephone or then to a vehicle).
As seen in FIG. 2, a generally cylindrical housing 46 is secured to the back of 47 of support 11 and has a like configured plate 48 (see also FIG. 3) secured to a cylindrical housing 46' rotatably and removably mounted in like configured cylindrical housing 46. Plate 48 has a Y-shaped flange 49 secured at the bottom having spaced ears 50, 51 receivable between spaced flanges 52, 53 extending upwardly from a circular boss 54 integral with a generally conically shaped housing portion 55.
A resilient suction cup 56 is mounted within the front surface of housing portion 55 having a shaft 57 extending therethrough (and through boss 54) between ears 50, 51. A lever 58 (FIG. 5) is fixed to a shaft 59 extending through ears 50, 51 and flanges 52, 53 and configured to shaft 57 so that, when lever 58 is rotated, shaft 57 moves up and down between ears 50, 51 to lock suction cup 56 to a support surface as is well-known in the suction cup art. If desired, a magnet 60 (see the dotted lines in FIG. 2) may be mounted within housing portion 55 to increase the grip of suction cup 56 when secured to a metallic surface.
It can be appreciated that flanges 52, 53 allow portions 55-56 and 60 to be pivoted about shaft 59 so that the suction cup 56 can be pivoted out of the way when device 10 is temporarily mounted to telephone 38 as seen in FIGS. 2, 3, and 5.
Thus, in operation, when device 10 is mounted on the cradle 37 of telephone 38 as heretofore discussed, the user can take coins from upper portion 20, as previously discussed, put them into the phone 38 and use the same. The device 10 is firmly and positively supported in writing position on telephone 38 (suction cup 56 being in the stored position in FIG. 5).
After use, the device 10 is quickly and easily removed from telephone 38 (see FIGS. 8 and 9) and returned to the vehicle of the user. Suction cup 56 can now be pivoted to the dotted line position 56' shown in FIG. 2 and the device 10 can now be secured to any convenient support surface, such as the dashboard of a vehicle, merely by rotating lever 58 and locking suction cup 56 to the desired support surface. If the latter is metallic, magnet 60 will increase the grip until it is desired to release the same by releasing lever 58.
Since housing 46' merely fits within housing 46, the housing 46', plate 48 and parts connected thereto can be removed, as seen in FIG. 5, when the device 10 is used on telephone 38. Further, since housing 46' also rotates within housing 46, the orientation of pad 18 can be changed so that it is convenient to use.
It can be seen that there is disclosed a portable memo pad device easily movable between car and remote telephone and temporarily secured at the telephone in a writing position. The device can be stored in a brief case for use in other remote locations, such as an airport terminal. After use, the device is easily returned to the vehicle and secured to a supporting surface thereon, preferably adjacent the driver, such as a part of the dashboard or windshield. | A portable memo pad holder device which can be transported in a vehicle between the vehicle and a remote phone. The device includes a removable pad and a mount adapted to fit on the standard cradle of a telephone in place of the transmitter-receiver. The mount also includes a suction cup for removably attaching the device to the dashboard or the like of a vehicle. Thus, the device can be moved back and forth between the vehicle and a remote telephone. | 1 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a divisional of application Ser. No. 11/027,860, filed on Dec. 30, 2004, the contents of which are fully incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a system and method for finishing fenestration openings.
BACKGROUND OF THE INVENTION
[0003] General contractors engaged in the construction of a commercial or residential building are responsible for scheduling various subcontractors to complete their assigned tasks in a timely manner. When a certain subcontractor's work is delayed for some reason, further delays may be caused for other subcontractors whose tasks are dependent on the first subcontractor. For instance, plumbing and electrical work must be completed before interior drywall can be hung; likewise painting and finishing cannot proceed until the drywall is hung. To the extent that a job can be planned so that as few subcontractors are dependent on the completion of each other's work as possible, a smoother job with fewer delays is likely to result.
[0004] While better scheduling and planning on the part of the general contractor can reduce these bottlenecks, some are unavoidable due to requirements imposed by current building materials. For example, fenestration openings are unfinished openings in the side of a building which will ultimately receive a window or door assembly. Currently, windows are delivered by the manufacturer having a frame which is attached to the framing members of the fenestration opening. Until this frame is installed, the finishing crews, which apply the exterior finish such as plastering to the building as well as the interior drywall crews, cannot complete their work. Accordingly, delays in shipment and installation of the windows and frames lead to significant problems in work scheduling for the building as a whole, which can potentially cause an entire job to fall behind schedule.
[0005] A need exists for a system and method which reduces the need for a high degree of coordination between subcontractors. With such a system and method, the burden on the window and door manufacturers to deliver on a tight schedule is reduced, and the general contractor regains a degree of control over his schedule without worrying about being held up by his custom window and door suppliers not delivering on time.
SUMMARY OF THE INVENTION
[0006] Accordingly, a fenestration cap system is provided as a separate piece from the frame of the window. The fenestration cap can be installed prior to the delivery of the widows and accompanying frames, and allows interior and exterior finishing to be completed without having to install the window and door systems. This allows more time for custom window and door orders to be filled by the supplier without holding up progress in other areas of the job. The waiting for the actual windows to arrive and be installed is no longer one of the critical paths of the job schedule, and may be completed at the convenience of the contractor.
[0007] This system is compatible with the frames of major door and window suppliers, and gives consumers the flexibility to choose the windows and doors that best fit their specific needs without being forced to make a selection due to manufacturer lead times. Furthermore, the present system is easy to install, and can be done by tradesmen with minimal training. The inclusion in certain embodiments of the present invention of flanges and stops reduces the need for careful measuring and placement of finishing materials such as drywall sheeting.
[0008] The fenestration cap system allows window and door openings to be made ready to receive their corresponding accessories, while at the same time being easily made weatherproof in the absence of these accessories with the addition of a simple piece of panel or sheeting.
[0009] Additional benefits are provided if accessories such as windows and doors are installed after finishing crews complete their work, which may include the application of plaster to the outside of the storefront, or the installation of drywall along the inside. In this case, The window and door systems installed within the fenestration cap do not need to be masked off by the finishing crews, and they are not in danger of being damaged by the finishing crews.
[0010] In one embodiment of the present fenestration cap system, future window replacement can be achieved by simply removing the window fasteners holding the window and possibly the frame within the fenestration cap, cutting out the perimeter window sealant, and sliding the window out leaving the integrity of the structural and building substrates in a finished undisturbed state.
[0011] In an exemplary embodiment, a window sill comprises a structural base having a first side and a second side, a fenestration cap attached to the structural base, a window frame mounted on the fenestration cap, and finish elements applied to the structural base and adjacent to the fenestration cap. The window frame may be removed from the fenestration cap without disturbing the finish elements.
[0012] In an alternative embodiment, a fenestration cap comprises a first surface for receiving a window and a second surface attached to the first surface for attachment to a fenestration opening. The window is separably detachable from the first surface and the fenestration opening is detachable from the second surface. Furthermore, detachability of the window from the first surface is independent of detachability of the fenestration opening from the second surface.
[0013] A method of installing a window in a window opening comprises providing a window opening and preparing the window opening for receiving a fenestration cap, installing a fenestration cap by placement within and attachment to the window opening in a primary step, and installing a window within the window opening by placement within and attachment to the fenestration cap in a secondary step.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 shows a side view of a prior art commercial window assembly;
[0015] FIG. 2 shows an isometric view of a prior art window assembly;
[0016] FIG. 3 shows a fenestration cap according to one embodiment of the present invention;
[0017] FIG. 4 shows a fenestration cap having a built in plaster key and a channel in the interior side according to another embodiment of the present invention;
[0018] FIG. 5 shows a recessed fenestration cap having a built in plaster key and a flush interior side according to one embodiment of the present invention;
[0019] FIG. 6 shows a recessed fenestration cap having a channel in the interior side according to one embodiment of the present invention;
[0020] FIG. 7 shows a recessed fenestration cap having a flush interior side according to one embodiment of the present invention;
[0021] FIG. 8 shows a fenestration cap having a built in plaster key which is attached to a window pane using a caulked butt joint;
[0022] FIG. 9 shows a recessed fenestration cap having a built in plaster key which is attached a window pane using a caulked butt joint;
[0023] FIG. 10 shows a sill detail of a fenestration cap anchored to a concrete slab;
[0024] FIG. 11 shows a fenestration cap according to an alternative embodiment of the present invention; and
[0025] FIG. 12 shows a head detail of a fenestration cap anchored to a concrete slab.
[0026] Before any embodiment of the invention is explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and arrangements of components set forth in the following description, or illustrated in the drawings. The invention is capable of alternative embodiments and of being practiced or being carried out in various ways. Also, it is to be understood that the terminology used herein is for the purpose of illustrative description and should not be regarded as limiting.
DETAILED DESCRIPTION OF THE INVENTION
[0027] The present fenestration cap was designed to systematically coordinate and weatherproof fenestration openings before the installation of commercial or residential windows or doors. In one embodiment, the fenestration cap is a permanent fixtures in the building in which it is installed. The present cap allows for plastering and installation of interior drywall to be completed after installation of the fenestration cap itself, all of which may be completed at the leisure of a general contractor before delivery of the windows and associated frames is even taken. As such, a delay in such delivery will not unnecessarily inconvenience the contractor and delay the job; plasterers and finishing crews no longer need to wait for the delivery of windows to a job site to complete their portions of the build.
[0028] Once the windows and frames do arrive, they can be installed separately by attachment to the fenestration cap with sheet metal screws or other appropriate fastening means. Furthermore, if the window panes themselves ever need to be replaced, the frames in which they are mounted can be easily detached from the fenestration cap without the need to remove the cap itself. Formerly, the unitary frame in which windows were mounted and which was attached directly to the window opening necessitated a complete tear-out of the window opening to replace the window itself. As such, windows and doors are made independent and easily replaceable building components rather than permanent parts of the building structure.
[0029] FIG. 1 is a side view of a prior art commercial window assembly showing a nail on concrete slab detail. A sill can 150 is attached directly to a concrete slab 101 using a fastener 102 . A pair of caulk beads 152 are also shown at the periphery of the interface between the sill can 150 and the concrete slab 101 . A sealant 106 is used to waterproof the intersection of the fastener 102 and the sill can 150 . A shim 107 may be used to position the sill can 150 on the concrete slab 101 . Also, backer rods 108 may be used to provide a stop for the application of the caulk bead 152 .
[0030] Such an arrangement is known by those skilled in the art to be prone to leakage. The sill can 150 , together with a sill can filler 155 and a sill can stop 160 forms a frame assembly which secures a window 170 . One or more top load gaskets 171 as well as a setting block 172 may also be used with this assembly to further secure, cushion and waterproof the window 170 .
[0031] With the embodiment shown, finish work on the window opening may only be completed once the window 170 and frame arrives. As such, the scheduling problems discussed above are common with this prior art embodiment. Furthermore, if the window 170 and frame needed to be changed, any plastering and drywall used to finish the window opening would have to be removed at that time.
[0032] FIG. 2 shows an isometric view of a prior art window assembly of a similar type to that shown in profile in FIG. 1 . Here, a vertical sill can 250 forms an assembly together with a sill can filler 255 and a sill can stop 260 to receive a window. The vertical sill can 250 is sealed to a jamb 201 using a caulk bead 25 . The vertical sill can 250 is shown at right angles to a horizontal sill can 250 which is secured to its mounting platform using a fastener 202 .
[0033] FIG. 3 shows a fenestration cap 300 according to a simplified embodiment of the present invention. Alternative fenestration caps are discussed in greater detail with reference to the following figures. Here, a fenestration cap 300 is shown having a vertical flashing 312 , a drywall channel 345 and a plaster key 346 , in addition to one or more screw races 305 . The dry wall channel is defined between a mounting flange 305 and a top side 305 b . The fenestration cap 300 is an independent piece separate from any sill can or window frame assembly which may be independently installed from the window to act as a terminal point for plaster and drywall installation as well as other finish work.
[0034] FIG. 4 shows one embodiment of a fenestration cap 400 according to the present invention. The cap shown in FIG. 4 is being used in a window opening framed by wood framing members 435 and faced on the exterior side by plywood sheeting 437 . FIG. 4 shows a sill can 450 supporting a window 470 . As is known to one skilled in the art, a head can of a like, though not necessarily identical design, may be used to support the top edge of the window 470 in a storefront. Similarly, the fenestration cap 400 may be used to finish the top of the window opening rather than the bottom as is shown in FIG. 4 so as to provide a platform for attachment of the head can.
[0035] As discussed above, finishing crews are responsible for the installation of the plaster 436 and drywall sheeting 438 , but these elements cannot be installed until a terminal point is provided for them to be finished against. In the prior art, this terminal point was provided by the sill can or frame of the window itself. However, this caused the previously mentioned problems of delays in construction while the finishing crews waited for the window and associated sill can and frame to be delivered.
[0036] In the embodiment shown in FIG. 4 , a fenestration cap 400 is provided as a single piece separate from any sill can or window frame; as such it may be independently installed and acts as a terminal point for plaster and drywall installation. To this end, the fenestration cap 400 includes a plaster key 446 on its exterior side. The front edge of the plaster key 446 is designed to act as a guide for the tradesperson applying the plaster 436 ; a trowel may easily be drawn along this edge of the plaster key 446 to quickly and neatly apply an even layer of plaster to the assembly. In one embodiment, the plaster 436 is applied to a depth of ⅞″. As mentioned above, because the fenestration cap 400 is provided as a single separate piece, plaster may be applied to the plaster key 446 prior to the installation of the window or frame, avoiding the risk of damage to these elements.
[0037] Similarly, in the shown exemplary embodiment, the fenestration cap 400 includes a base 415 , a top side 417 generally parallel to the base, as well as a first support 419 and a second support 421 between the base and the top side. The key 446 has at least a portion that extends perpendicularly from a side 411 defining a flashing 412 , and along the same plane as the top side 471 . The exemplary embodiment fenestration cap also includes a drywall channel 445 provided as a guide to receive a piece of drywall sheeting 438 such as standard ⅝″ sheetrock. This channel aids an unskilled laborer in the installation of interior drywall, plaster or paneling. The built in receiving and self-aligning channel creates a level fit for the installation of interior finish materials. Accordingly, the sheeting running from a corner bead 439 to the fenestration cap 400 can be quickly and accurately installed in a level position without the time consuming process of shimming or manual adjustment of the sheeting necessary with prior art systems.
[0038] In the embodiment of the present invention shown in FIG. 4 , inserting the drywall sheeting 438 into the drywall channel 445 is all that is necessary to present a finished appearance for the inside of the window assembly. It is not necessary to tape or spackle the exposed joint between the drywall sheeting 438 and the fenestration cap 400 which lies below the water dam 411 . Thus, further time and expense is saved in the installation process. The drywall channel 445 may include one or more vertical fins 417 therein, which aid in gripping the portion of drywall sheeting 438 inserted into the drywall channel 445 . These fins also provide a cushioning effect for the drywall sheeting 438 during seismic activity.
[0039] In one embodiment of the present invention, the fenestration cap 400 is installed in the window opening using one or more wood screws 430 through the vertical flashing 412 and a mounting flange 415 to secure the fenestration cap 400 to the underlying structure of the window opening, namely the wood framing members 435 and/or the plywood sheeting 437 . A vertical flashing 412 may be provided allowing the fenestration cap 400 to be attached to the plywood sheeting 437 . A self healing membrane 434 may be placed between the vertical flashing 412 and the plywood sheeting 437 to provide further waterproofing for the underlying structure of the window opening. The self healing membrane 434 may be in one embodiment a continuous waterproof self healing rubberized membrane is manufactured from polypropylene. The vertical flashing 412 also provides additional waterproofing to the finished window assembly by providing a water barrier to any water which infiltrates behind the plaster 436 . The fenestration cap 400 may be attached by its interior side with one or more additional wood screws 430 to the wood framing members 435 .
[0040] An expansion cavity 433 may be provided between the fenestration cap 400 and the wood framing members 435 which may contain a foam strip, 3/16″ thick in one exemplary embodiment to act as a shock absorber in the event of thermal or other expansion of the underlying members or seismic movement.
[0041] It will be understood by one skilled in the art that the inventive concepts of the invention described herein are not limited to a fenestration cap for use only with the specific materials discussed above, such as plaster and drywall for instance. In lieu of plaster for example, a variety of siding materials can be used to finished the exterior of the storefront assembly shown in FIG. 4 . Likewise, plaster or paneling or a variety of other interior finishing materials may be used instead of the drywall sheeting 438 discussed above.
[0042] The fenestration cap 400 shown in FIG. 4 can be made from aluminum, vinyl, steel, plastic and other appropriate materials known to those skilled in the art. In one exemplary embodiment, the fenestration cap may be manufactured as an extruded aluminum piece in twenty-four foot lengths. This exceeds the length of typical extruded pieces used in window openings such as j-molds, for which the industry standard length is ten feet. Accordingly, with this embodiment of the present invention, the need for making time consuming splices between the lengths is reduced.
[0043] Furthermore, the width of the fenestration cap may be designed in various widths to fit various windows and window openings. The present invention is designed to work with window systems from multiple companies. As is known to one skilled in the art, the width of a commercial window is customarily measured with reference to its mullion width. These widths come in standard sizes including 2, 3, 4, 4.5 and 6 inches in width, among others. It is envisioned that a fenestration cap may be designed to match each of these standard window widths, although one skilled in the art will understand that a fenestration cap according to the present invention can be made to match any width window. FIG. 4 shows a window 4.5 inches in width, and the fenestration cap 400 shown therein has been designed to match a window of this width.
[0044] The fenestration cap 400 may be assembled in the contractor's shop or on the job site itself into a custom system for any size window opening by cutting stock lengths of the fenestration cap 400 at forty-five degree angles (or any other set of complementary angles). These lengths can then be attached to each other using fasteners passing through the integral screw races 405 of adjacent lengths of fenestration cap 400 . For an aluminum fenestration cap, stainless steel sheet metal screws can be used as fasteners.
[0045] If the fenestration cap 400 is assembled in the contractor's shop and transported to the job site, a blank made of styrofoam or other material may be inserted into the center of the fenestration cap assembly to stiffen it for transport. This blank may be secured within the assembly using double-sided tape. Furthermore, after the fenestration cap is installed in the window opening, a blank secured within the fenestration cap 400 assembly using double sided tape may be also used to weatherproof the capped window opening in lieu of the window itself. Taped plastic sheeting may also be used for this purpose. In any event, fenestration cap assembly provides and easy base from which to tape or otherwise weatherproof a window opening prior to the installation of the window assembly.
[0046] The sill can 450 shown in FIG. 4 is an industry standard sill can having a number of interlocking parts. A sill can filler 455 and a sill can stop 460 snap into place within the sill can 450 to lock a window 470 in position. The window 470 is firmly held by a pair of top load gaskets 471 , which may be neoprene gaskets. The sill can 450 is shown engaging window 470 through the pair of top load gaskets 471 and a setting block 472 . These top load gaskets 471 are held partially snapped into receiving tracks in the sill can filler 455 and the sill can stop 460 . These gaskets are also known to those skilled in the art as self-locking gaskets, given that the weight of the window 470 bears on these gaskets to create a seal between the gaskets 471 and the window 470 .
[0047] In one embodiment of the present invention, at some point after the fenestration cap 400 itself has been installed in the window opening, the sill can 450 , having a window 470 therein, may be lifted onto the length of fenestration cap 400 shown in FIG. 4 . The sill can 450 can then be attached to the fenestration cap 400 using one or more sheet metal screws 451 . In an exemplary embodiment, the window 470 may be surrounded on multiple sides by either a sill can or frame which abuts a length of fenestration cap to which the sill can or frame may be attached.
[0048] If the fenestration cap 400 is used with a frame such as the sill can 450 and related components shown in FIG. 4 , the point of attachment of the sill can 450 to the fenestration cap 400 must be made waterproof. Accordingly, before the sill can 450 is attached to the fenestration cap 400 using the sheet metal screws 451 , a caulk bead 452 is laid down therebetween to waterproof the joint. In one embodiment, the caulk used for the caulk bead 452 is structural grade silicone. At the portion of the joint nearest the exterior side of the storefront, a gap of set height 453 is provided which is designed to match the warranty requirements of the standard window sealants used in the industry. In the embodiment shown in FIG. 4 , this gap has a height of ⅜ inches.
[0049] A water dam 411 may be provided at the interior side of the caulk bead 452 as a further moisture barrier in the event that water is able to infiltrate through to the interior side of the caulk bead 452 . The water dam 411 also provides a stop allowing for easy installation of the window and sill can 450 . Once the fenestration cap 400 is in place in a window opening, an unskilled laborer would easily be able to install the sill can 450 and related components to provide a finished storefront by lifting the window assembly up and into the opening within the fenestration cap assembly, placing the interior edge of the sill can 450 firmly against the water dam 411 . As such, no measuring is required for the installation of the window assembly itself when the fenestration cap 400 has been used to frame the window opening ahead of time.
[0050] Furthermore, even if despite all the precautions built into the design of the fenestration cap 400 , water is able fully infiltrate the joint in the area of the caulk bead 452 and pass over the water dam 411 , the fenestration cap 400 fully spans the width of the window opening in which it is placed so that any water which does manage to flow over the fenestration cap 400 is directed over, rather than into, the wall on which the fenestration cap 400 rests.
[0051] The fenestration cap 400 may be provided with a thermal break 410 to reduce the transfer of heat through the fenestration cap 400 to help meet energy efficiency building requirements such as California's Title 24 requirements. Accordingly, an insulation material is formed in a cavity of the fenestration cap 400 . This insulation material has sufficient strength such that after it is formed in the cavity, a portion of the fenestration cap 400 can be removed in the vicinity of the insulation such that the fenestration cap 400 becomes two thermally separate pieces joined only by the insulation. This helps to substantially thermally isolate the interior from the exterior of the finished storefront by preventing heat transmission through the fenestration cap 800 .
[0052] The fenestration cap 400 has the additional advantage that over prior art systems in that it can span doorway openings in a storefront and need not be trimmed to the jamb of a doorway. With the addition of a separate threshold unit, the section fenestration cap 400 , spanning the bottom of a doorway, presents a finished appearance. Accordingly, a single length or series of lengths of the fenestration cap 400 can be made to span the base of an entire storefront serving as both a sill of a window and a door threshold.
[0053] FIG. 5 shows a fenestration cap 500 for use with a frameless window system. While the fenestration cap 500 shares many of the same elements as the cap shown in FIG. 4 , the cap 500 is shown engaging the window 570 through a top load gasket 571 and a setting block 572 , rather than incorporating a separate sill can, as is the case in the cap of FIG. 4 . In one embodiment, the top load gasket 571 may be provided by a silicone glazed bead.
[0054] As in the previous embodiment, the fenestration cap 500 is attached to the wood framing members 535 and plywood sheeting 537 using a series of wood screws 530 . The fenestration cap 500 is provided with a drywall channel 545 and plaster key 546 designed to receive drywall sheeting 538 and plaster 536 . A spacer 509 may be provided to support the drywall sheeting 538 in the area of a corner bead 539 .
[0055] FIG. 6 shows a recessed fenestration cap having a channel in the interior side according to one embodiment of the present invention. In FIG. 6 , the top and front edges of the plaster key 647 and the top edge of the lip 649 are designed to act as guides to the tradesperson applying the plaster 436 to the assembly; a trowel may easily be drawn along these edges to quickly and neatly apply an even layer of plaster in the space between the plaster key 647 and the lip 649 . The surface created by plastering between the plaster key 647 and the lip 649 will not be completely horizontal however; the fenestration cap 600 is designed so that when level, the top edge of the plaster key 647 lies on a 2% decline from the horizontal with respect to the top edge of the lip 649 . This encourages water to shed off of the architectural reveal created by this plastered surface toward the exterior of the storefront. Furthermore, the fenestration cap 600 is provided with a serrated texture 648 to better anchor the plaster to the fenestration cap 600 . Also, the plaster key 647 is provided with holes drilled therein (not shown) so that the plaster applied below the plaster key 647 and the plaster applied to the side of the plaster key 647 is able to form one contiguous and stable mass, leading to increased durability. FIG. 6 also depicts one of two sheet metal screws 651 entering a cavity. In some embodiments of the present invention, one or more sheet metal screws is used to affix the sill can 650 to the fenestration cap. If water leaks under the sill can and above the fenestration cap, it could leak down through the sheet metal screw 651 hole. However, if the screw hole goes through a portion of the fenestration cap into the cavity, the cavity will serve as a reservoir to hold the water, preventing water from entering into the interior, and trapping water in the cavity until it evaporates.
[0056] FIG. 7 shows a recessed fenestration cap 700 having a flush interior side according to one embodiment of the present invention. The fenestration cap 700 is attached to the wood framing members 735 and plywood sheeting 737 using a series of wood screws 730 . The fenestration cap 700 is attached to an assembly comprising a sill can 750 , sill can filler and 755 sill can stop 760 using sheet metal screws 751 and a caulk bead 752 . This assembly is shown engaging the window 770 through a top load gasket 771 and a setting block 772 . In contrast to FIGS. 4 , 5 and 6 however, the fenestration cap 700 is not provided with a drywall channel designed to receive drywall sheeting. Instead, the fenestration cap 700 is designed as a relatively flush assembly which may be placed over a corner bead 739 applied to finish the joint between the drywall sheeting 738 and the wood framing members 735 .
[0057] FIG. 8 shows a fenestration cap 800 attached to a window 870 using a butt joint 895 . The arrangement shown in FIG. 8 is a counterpart to the fenestration cap 500 of FIG. 5 for use with a frameless window system. While the fenestration cap 500 supports the sill of a window in a frameless window system, the fenestration cap 800 may be applied to the jamb of such a window opening to support the sides of the window 870 .
[0058] As in the previous figures, the fenestration cap 800 is provided with a plaster key 846 to facilitate the easy application of the plaster 836 , and a drywall channel 845 to facilitate the installation of the drywall sheeting 838 . The fenestration cap 800 is secured to the wood framing members 835 and the plywood sheeting 837 using one or more wood screws 830 . Furthermore, the fenestration cap 800 is provided with a thermal break 810 , which may be supplemented with the creation of a saw cut 896 in the fenestration cap 800 to substantially thermally isolate the interior from the exterior of the finished storefront, preventing heat transmission through the fenestration cap 800 .
[0059] FIG. 9 shows a recessed fenestration cap 900 having a built in plaster key 947 which is attached a window pane using a caulked butt joint. The fenestration cap 900 is similar to the fenestration cap 800 of FIG. 8 in that it may be applied to the jamb of a window opening in a frameless window system to support the window therein. However, it differs in that it features a set back similar to that used in the fenestration cap 600 of FIG. 6 , wherein the top and front edges of the plaster key 947 and the top edge of the lip 949 are designed to act as guides to the tradesperson applying the plaster 936 to the assembly.
[0060] As in FIG. 6 , the surface created by plastering between the plaster key 947 and the lip 949 will not be completely horizontal. The fenestration cap 900 is designed so that when level, the top edge of the plaster key 947 lies on a slight decline from the horizontal with respect to the top edge of the lip 949 . This encourages water to shed off of this architectural reveal toward the exterior of the storefront. The fenestration cap 900 is also provided with a serrated texture 948 to better anchor the plaster 936 to the fenestration cap 900 .
[0061] FIG. 10 is an alternative embodiment of the present invention wherein a sill detail a fenestration cap 1000 shown is anchored to a concrete slab 1001 using a fastener 1002 . The concrete slab 1001 may be part of an overhanging eve. In place on the fenestration cap 1000 are a sill can 1050 , a sill can filler 1055 , and a sill can stop 1060 which, though the top load gaskets 1071 secure the window 1070 .
[0062] The gap between the sill can 1050 and the fenestration cap 1000 is sealed with a caulk bead 1052 . As in other embodiments, a gap of set height 1053 is provided as part of the caulk bead 1052 to match industry standard warranty requirements. A water dam 1011 is provided at the interior side of the caulk bead 1052 as a moisture barrier in the event that water is able to infiltrate through to the interior side of the caulk bead 1052 , and to provide a stop for easy installation of the sill can 1050 .
[0063] The embodiment of FIG. 10 additionally shows that the fenestration cap 1000 is slightly wedge shaped, having a narrower edge on the exterior side. As such, water will be more inclined to run to the outside of the window 1070 both if it infiltrates between the fenestration cap 1000 and the sill can 1050 , and if it gets into the sill can 1050 itself. In prior art models, if water infiltrated the sill can 1050 for example by flowing between it and the sill can filler 1055 , it would pool within the sill can. Weep holes were sometimes added in the sill can 1050 to aid in drainage, but cannot prevent pooling in the event of an unfavorable alignment of the sill can 1050 itself.
[0064] FIG. 11 shows a fenestration cap 1100 according to an alternative frameless embodiment of the present invention wherein the window 1170 is mounted directly on the fenestration cap 1100 using a caulk joint 1195 . As is the previous figures, the fenestration cap 1100 is provided with a plaster key 1146 to facilitate the easy application of the plaster 1136 , and a drywall channel 1145 to facilitate the installation of the drywall sheeting 1138 . The fenestration cap 1100 is secured to the wood framing members 1135 and the plywood sheeting 1137 using one or more wood screws 1130 .
[0065] FIG. 12 shows a head detail of a fenestration cap 1200 anchored to an overhang 1201 . The fenestration cap 1200 is of a type which can be attached on a continuous eve or overhang 1201 without need of a flange. In the embodiment shown, the fenestration cap 1200 is attached using the fastener 1202 . On the fenestration cap 1200 is mounted an assembly comprising a sill can 1250 , sill can filler 1255 and sill can stop 1260 . This assembly may be mounted using sheet metal screws 1251 , and seamed using a caulk bead 1252 . A window 1270 may be mounted in this assembly using top load gaskets 1271 . The fenestration cap 1200 may be installed before the sill can 1250 to allow for the completion of work involving the plaster 1236 and drywall sheeting 1238 , the latter of which fits easily into the drywall channel 1245 .
[0066] The preceding description has been presented with reference to some embodiments of the invention. Workers skilled in the art and technology to which this invention pertains will appreciate that alterations and changes in the described structure may be practiced without meaningful departing from the principal, spirit and scope of this invention. Accordingly, the foregoing description should not be read as pertaining only to the precise structures and methods described and illustrated in the accompanying drawings, but rather should be read consistent with and as support to the following claims which are to have their fullest and fair scope. For instance, FIG. 10 depicts a fenestration cap that is slightly wedge shaped, and thus parts of the fenestration cap may not be perfectly parallel or perfectly perpendicular in reference to one another. Therefore, as used herein, parallel and perpendicular could mean substantially parallel and substantially perpendicular. | In an exemplary embodiment, a window sill comprises a structural base having a first side and a second side, a fenestration cap attached to the structural base, a window frame mounted on the fenestration cap and finish elements applied to the structural base and adjacent to the fenestration cap. The window frame may be removed from the fenestration cap without disturbing the finish elements. Alternatively, a method of installing a window in a window opening comprises providing a window opening and preparing the window opening for receiving a fenestration cap, installing a fenestration cap by placement within and attachment to the window opening in a primary step, and installing a window within the window opening by placement within and attachment to the fenestration cap in a secondary step. | 4 |
FIELD OF THE INVENTION
[0001] This invention relates to the production of sheet glass by the fusion process and, in particular, to techniques for controlling the formation of devitrification defects in glass made by this process. The techniques are particularly useful when the fusion process is employed to produce high silica glass sheets (e.g., glass sheets having a weight percent of silica of at least 60%) which are designed for use as substrates in the manufacture of liquid crystal displays, e.g., AMLCDs.
BACKGROUND OF THE INVENTION
[0002] A. The Fusion Process
[0003] The fusion process is one of the basic techniques used in the glass making art to produce sheet glass. See, for example, Varshneya, Arun K., “Flat Glass,” Fundamentals of Inorganic Glasses, Academic Press, Inc., Boston, 1994, Chapter 20, Section 4.2., 534-540. Compared to other processes known in the art, e.g., the float and slot draw processes, the fusion process produces glass sheets whose surfaces have superior flatness and smoothness. As a result, the fusion process has become of particular importance in the production of the glass substrates used in the manufacture of liquid crystal displays (LCDs).
[0004] The fusion process, specifically, the overflow downdraw fusion process, is the subject of commonly assigned U.S. Pat. Nos. 3,338,696 and 3,682,609, to Stuart M. Dockerty, the contents of which are incorporated herein by reference. A schematic drawing of the process of these patents is shown In FIG. 1. As illustrated therein, the system includes a supply pipe 9 which provides molten glass to a collection trough 11 formed in a refractory body 13 known as an “isopipe.”
[0005] Once steady state operation has been achieved, molten glass passes from the supply pipe to the trough and then overflows the top of the trough on both sides, thus forming two sheets of glass that flow downward and then inward along the outer surfaces of the isopipe. The two sheets meet at the bottom or root 15 of the isopipe, where they fuse together into a single sheet. The single sheet is then fed to drawing equipment (represented schematically by arrows 17 ), which controls the thickness of the sheet by the rate at which the sheet is drawn away from the root. The drawing equipment is located well downstream of the root so that the single sheet has cooled and become rigid before coming into contact with the equipment.
[0006] As can be seen in FIG. 1, the outer surfaces of the final glass sheet do not contact any part of the outside surface of the isopipe during any part of the process. Rather, these surfaces only see the ambient atmosphere. The inner surfaces of the two half sheets which form the final sheet do contact the isopipe, but those inner surfaces fuse together at the root of the isopipe and are thus buried in the body of the final sheet. In this way, the superior properties of the outer surfaces of the final sheet are achieved.
[0007] In a commercial setting, the location and inclination of isopipe 13 needs to be adjustable with respect to the equipment used to melt and refine the raw ingredients from which the glass sheet is made. Although theoretically such adjustability could be achieved in a system in which the connection between the melter/finer and the fusion system was completed closed (i.e., a system in which entire feed system to the isopipe was filled with molten glass), in practice, adjustability is achieved by connecting the melter/finer to the fusion system by forming a free surface of molten glass.
[0008] [0008]FIGS. 2 and 3 illustrate such a connection, where as above, 9 is the supply pipe to isopipe 13 , 19 is the exit from the melter/finer system (referred to herein as a “downcomer” since it preferably has a substantially vertical (downward) orientation), arrow 22 shows the direction of flow of molten glass 31 , and 21 is the free surface of the molten glass, the height of which relative to the height of molten glass in the isopipe's trough 11 is determined by (1) the rate of flow of molten glass out of the downcomer and (2) the resistance to fluid flow of the supply pipe/isopipe combination. As can be seen in these figures, because the characteristic cross-sectional dimension of downcomer 19 (e.g., the diameter of the downcomer) is smaller than the characteristic cross-sectional dimension of supply pipe 9 (e.g., the diameter of the entrance 18 to the supply pipe), the downcomer and supply pipe can be readily moved relative to one another. In this way, the desired adjustability between the melter/finer and the fusion system is achieved.
[0009] It should be noted that for a downcomer whose exit end 20 is submerged in molten glass, the height of free surface 21 relative to the height of molten glass in trough 11 is relatively insensitive to changes in the depth of submersion of the exit end. To provide a spatial reference for describing the invention, the phrase “nominal free surface” is used herein to indicate the location of free surface 21 when exit end 20 is just submerged in the molten glass. The reference number 21 N is used to identify the nominal free surface.
[0010] For essentially any practical submersion of the exit end of the downcomer, the nominal free surface and the actual free surface will be at essentially the same location. Accordingly, in FIGS. 2 and 3 both reference number 21 and reference number 21 N are used to identify the interface between molten glass 31 and the surrounding atmosphere 33 (typically air).
[0011] It should also be noted that because supply pipe 9 (as well as downcomer 19 ) are made of opaque refractory materials (e.g., platinum or a platinum alloy), neither the actual free surface nor the nominal free surface of the molten glass can be visually observed. However, their locations can be accurately estimated using physical modeling (e.g., oil modeling). In this connection, it should be noted that the free surfaces 21 shown in the figures and, in particular, in FIGS. 8 - 9 and 11 - 12 , are simplified drawings for purposes of illustration, it being understood that the actual free surfaces will have more complex shapes as a result of the molten glass transitioning from a smaller diameter conduit to a larger diameter conduit at a free surface. Further, knowledge of the exact locations/configurations of the actual free surface and the nominal free surface is not needed to practice the invention since, as explained in detail below, by examining the finished glass for defects, specifically, for devitrification and blister defects, one can determine if the spatial relationship between the downcomer and the molten glass is within the operative range defined by the invention.
[0012] B. LCD Glasses
[0013] Corning Incorporated, the assignee of this application, has sold glass sheets for use as substrates in the manufacture of liquid crystal displays under the trademarks 1737 and EAGLE 2000. See, U.S. Pat. Nos. 5,374,595 to Dumbaugh, Jr. et al. and 6,319,867 to Chacon et al., respectively, the relevant portions of which are incorporated herein by reference.
[0014] EAGLE 2000 glass has a silica content of approximately 63.3 wt. %, while 1737 glass has a silica content of approximately 57.8 wt. %. Because of its higher silica content, EAGLE 2000 has a greater tendency to devitrify than 1737, e.g., to form cristobalite, the high temperature crystalline form of silica.
[0015] To address EAGLE 2000's greater tendency to devitrify, its formulation includes a higher percentage of boron oxide (B 2 O 3 ), specifically, approximately 10.3 wt. % B 2 O 3 for EAGLE 2000 versus approximately 8.4 wt. % for 1737.
[0016] Notwithstanding this higher level of B 2 O 3 , during trial manufacturing runs, considerable cristobalite devitrification was observed when EAGLE 2000 glass was manufactured using equipment which previously had successfully produced 1737 glass without the generation of high levels of devitrification. The devitrification of EAGLE 2000 glass was first observed in the compression beads at the edges of the glass sheet (i.e., the beads engaged by the drawing equipment) and eventually throughout the glass sheet, including the quality portion of the sheet intended ultimately to form the LCD substrate.
[0017] The present invention is concerned with identifying the source of this devitrification and with providing methods and apparatus for eliminating this defect without introducing other defects (specifically, blister defects) into the finished glass sheets.
SUMMARY OF THE INVENTION
[0018] In accordance with a first aspect, the invention provides a molten glass delivery system for use in producing sheet glass by a fusion process comprising:
[0019] (a) a first conduit ( 9 ) which has a first characteristic cross-sectional dimension (e.g., a cross-sectional diameter of about 8.5 inches); and
[0020] (b) a second conduit ( 19 ) which has an exit end ( 20 ) and a second characteristic cross-sectional dimension (e.g., a cross-sectional diameter of about 3.5 inches);
[0021] wherein:
[0022] (i) the first conduit ( 9 ) receives molten glass from the second conduit ( 19 );
[0023] (ii) a portion of the first conduit ( 9 ) surrounds a portion of the second conduit ( 19 );
[0024] (iii) the first characteristic cross-sectional dimension is larger than the second characteristic cross-sectional dimension so that a free surface ( 21 ) of molten glass ( 31 ) is formed between the first and second conduits; and
[0025] (iv) the first ( 9 ) and second ( 19 ) conduits are positioned relative to one another (e.g., by moving the first conduit or by moving the second conduit or by moving both the first and second conduits) so that the spatial relationship between the exit end ( 20 ) of the second conduit ( 19 ) and the free surface ( 21 ) of the molten glass ( 31 ) results in neither substantial numbers of devitrification defects ( 27 , 29 ) (e.g., commercially unacceptable numbers of devitrification defects) nor substantial numbers of blister defects ( 35 ) (e.g., commercially unacceptable numbers of blister defects) in the finished sheet glass for a glass that is devitrification sensitive (e.g., a glass which comprises at least 60 wt. % SiO 2 and/or at least 9 wt. % B 2 O 3 ).
[0026] In accordance with a second aspect, the invention provides a method for providing molten glass to apparatus ( 11 , 13 , 15 ) which produces sheet glass by a fusion process, said method comprising:
[0027] (a) providing a first conduit ( 9 ) which has a first characteristic cross-sectional dimension;
[0028] (b) providing a second conduit ( 19 ) which has an exit end ( 20 ) and a second characteristic cross-sectional dimension, said second characteristic cross-sectional dimension being smaller than said first characteristic cross-sectional dimension;
[0029] (c) nesting a portion of the second conduit ( 19 ) within a portion of the first conduit ( 9 );
[0030] (d) flowing molten glass out of the second conduit ( 19 ) and into the first conduit ( 9 ), said molten glass forming a free surface ( 21 ) between the first and second conduits; and
[0031] (e) selecting the relative locations of the first ( 9 ) and second ( 19 ) conduits so that the spatial relationship between the exit end ( 20 ) of the second conduit ( 19 ) and the free surface ( 21 ) of the molten glass ( 31 ) results in neither substantial numbers of devitrification defects nor substantial numbers of blister defects in the finished sheet glass for glass that is devitrification sensitive.
[0032] Step (e) of the second aspect of the invention is preferably performed by:
[0033] (i) moving the first ( 9 ) and second ( 19 ) conduits apart (away from one another) so that the exit end ( 20 ) of the second conduit ( 19 ) is sufficiently above a nominal free surface ( 21 N) of the molten glass ( 31 ) so that substantial numbers of blister defects appear in the finished sheet glass; and
[0034] (ii) moving the first ( 9 ) and second ( 19 ) conduits together (towards one another) until substantial numbers of blister defects no longer appear in the finished sheet glass.
[0035] Even more preferably, step (e) also includes the further step of moving the first ( 9 ) and second ( 19 ) conduits together (towards one another) beyond the point where substantial numbers of blister defects no longer appear in the finished sheet glass but not so far as to cause substantial numbers of devitrification defects to appear in the finished sheet glass for glass that is devitrification sensitive. It should be noted that devitrification defects normally take some time to develop so that one will have to observe the finished glass for a period of time to determine if the conduits have been moved too close together. Blister defects, on the other hand, develop rapidly when the conduits are too far apart.
[0036] The “moving” of the first and second conduits in the preferred procedures for performing step (e) can be achieved by moving the first conduit, the second conduit, or both the first and second conduits. Typically, just the second conduit will be moved.
[0037] The reference numbers used in the above summaries of the first and second aspects of the invention are for the convenience of the reader and are not intended to and should not be interpreted as limiting the scope of the invention. More generally, it is to be understood that both the foregoing general description and the following detailed description are merely exemplary of the invention, and are intended to provide an overview or framework for understanding the nature and character of the invention as it is claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0038] [0038]FIG. 1 is a schematic drawing illustrating a representative construction for a supply pipe and an isopipe for use in an overflow downdraw fusion process for making flat glass sheets.
[0039] [0039]FIG. 2 is a schematic diagram illustrating the junction between a downcomer and a supply pipe where the exit end of the downcomer is below the nominal free surface of the molten glass in the supply pipe.
[0040] [0040]FIG. 3 is an expanded view of the junction between the downcomer and the supply pipe of FIG. 2.
[0041] [0041]FIG. 4 is a photomicrograph of a crystalline defect (devitrification defect) of the type which the present invention addresses.
[0042] [0042]FIGS. 5A and 5B are plots showing surface enrichment of SiO 2 for 1737 and EAGLE 2000 glass, respectively.
[0043] [0043]FIGS. 6A and 6B are plots showing surface depletion of B 2 O 3 for 1737 and EAGLE 2000 glass, respectively.
[0044] [0044]FIGS. 7A and 7B are plots showing surface enrichment of SiO 2 and surface depletion of B 2 O 3 , respectively, for 1737 glass (open data points) and EAGLE 2000 glass (solid data points).
[0045] [0045]FIGS. 7C and 7D are photomicrographs of the top surfaces of samples of EAGLE 2000 and 1737 glass, respectively, after a heat treatment at 1300° C. for 96 hours.
[0046] [0046]FIG. 8 is a schematic diagram illustrating the junction between a downcomer and a supply pipe where the exit end of the downcomer is above the nominal free surface of the molten glass in the supply pipe.
[0047] [0047]FIG. 9 is an expanded view of the junction between the downcomer and the supply pipe of FIG. 8.
[0048] [0048]FIG. 10 is a photomicrograph of a gaseous defect (blister defect) of the type which the present invention addresses. The defect shown is representative of the type of blister defects seen at the fusion line for glass drawn to a thickness of approximately 0.7 millimeters. It has a long axis of 239 microns and a short axis of 42 microns. Larger and smaller dimensions are common for defects of this kind. The photograph was taken looking down at the glass sheet.
[0049] [0049]FIG. 11 is a schematic diagram illustrating the junction between a downcomer and a supply pipe where the exit end of the downcomer is essentially at the nominal free surface of the molten glass in the supply pipe.
[0050] [0050]FIG. 12 is an expanded view of the junction between the downcomer and the supply pipe of FIG. 11.
[0051] The foregoing drawings, which are incorporated in and constitute part of the specification, illustrate various embodiments of the invention, and together with the description, serve to explain the principles of the invention. It is to be understood, of course, that both the drawings and the description are explanatory only and are not restrictive of the invention.
[0052] The reference numbers used in the drawings correspond to the following:
[0053] [0053] 9 supply pipe
[0054] [0054] 11 collection trough
[0055] [0055] 13 isopipe
[0056] [0056] 15 root of isopipe
[0057] [0057] 17 arrows schematically indicating drawing equipment
[0058] [0058] 18 entrance to supply pipe
[0059] [0059] 19 downcomer
[0060] [0060] 20 exit end of downcomer
[0061] [0061] 21 actual free surface of molten glass
[0062] [0062] 21 N nominal free surface of molten glass
[0063] [0063] 22 arrow indicating glass flow in supply pipe
[0064] [0064] 23 sample of EAGLE 2000 glass
[0065] [0065] 25 support for sample of EAGLE 2000 glass
[0066] [0066] 27 cristobalite crystal
[0067] [0067] 29 sac surrounding cristobalite crystal
[0068] [0068] 31 molten glass in supply pipe
[0069] [0069] 33 atmosphere above free surface
[0070] [0070] 35 blister defect
DETAILED DESCRIPTION OF THE INVENTION
[0071] [0071]FIG. 4 is a photomicrograph of a cristobalite crystal of the type that was observed when EAGLE 2000 glass was processed into glass sheets (thickness=0.63 millimeters) using equipment which previously had successfully processed 1737 glass without serious devitrification problems. The reference numbers used in this figure refer to the following: 23 —EAGLE 2000 glass; 25 —support used in preparing photomicrograph; 27 —cristobalite crystal; and 29 —sac surrounding cristobalite crystal. As can be seen in this figure, in addition to constituting an internal defect, the cristobalite crystal has also affected the flatness of the outer surfaces of the glass sheet.
[0072] Analysis of sac 29 revealed silica enrichment and boron depletion in the residual glass. In accordance with the invention, this observation was interpreted as indicating the source of the devitrification as something other than normal devitrification of EAGLE 2000 glass resulting from cooling of the glass below its liquidus temperature. In particular, this observation was interpreted as indicating highly silica-enriched glass as the source of the devitrification.
[0073] In addition to the sac analysis, a high level of devitrification of EAGLE 2000 glass was observed during a trial run after a translation of isopipe 13 and supply pipe 9 with respect to downcomer 19 . This observation led to the hypothesis that the source of the devitrification was free surface 21 at the junction between the downcomer and the supply pipe.
[0074] To test this hypothesis, laboratory experiments were performed to determine if stagnant EAGLE 2000 glass behaved differently from stagnant 1737 glass. The experiments were performed as follows. Samples of 1737 and EAGLE 2000 glasses were cut, cleaned, and stacked to a depth of approximately five millimeters in rectangular platinum crucibles whose dimensions were 45 millimeters by 40 millimeters by 10 millimeters deep. This geometry provided considerable surface area to avoid edge effects caused by contact of the glass with the crucible's walls and was shallow enough to reduce the impact of any vertical mixing due to density or thermal gradients.
[0075] The crucibles were placed in a resistance heated furnace at 1200° C., 1250° C., and 1300° C. for periods of 2, 4, and 8 days. After the heat treatment, samples were cut from the center of each crucible, potted in epoxy, and polished for chemical analysis with an electron microprobe instrument. Analyses were performed at 50 micrometer intervals from a point 40 micrometers below the surface to a depth of 2.49 millimeters. Well-characterized 1737 glasses were used to calibrate the instrument.
[0076] Represent results are shown in FIGS. 5A (1737 SiO 2 ), 5 B (EAGLE 2000 SiO 2 ), 6 A (1737 B 2 O 3 ), and 6 B (EAGLE 2000 B 2 O 3 ). The data in these figures is normalized to the nominal SiO 2 and B 2 O 3 concentrations (see above) of the glass under study. Note the use of different vertical scales for the 1737 and EAGLE 2000 SiO 2 results. All of the data presented is for a 96 hour (4 day) heat treatment at the temperatures indicated.
[0077] The greater enrichment of SiO 2 and the greater loss of B 2 O 3 for EAGLE 2000 glass compared to 1737 glass is evident from these graphs. Moreover, the variation from bulk composition extends much farther from the surface for the EAGLE 2000 glass than for the 1737 glass. This later effect can be seen most clearly in FIGS. 7A and 7B which show, respectively, SiO 2 enrichment and B 2 O 3 depletion at 96 hours for a treatment at 1250° C. for 1737 glass (open data points) and EAGLE 2000 (solid data points).
[0078] An examination of FIGS. 5B and 6B show that the silica enrichment and boron depletion are temperature dependent, with the levels of enrichment and depletion being especially great at 1300° C.
[0079] [0079]FIG. 7C is a photomicrograph of the top surface of a sample of EAGLE 2000 glass prepared as described above and held in the resistance heated furnace for 96 hours at 1300° C. The presence of crystals on the surface is evident. For comparison, FIG. 7D shows the crystal-free surface of a sample of 1737 glass treated in the same manner. Surface crystallization is also observed for EAGLE 2000 glass after 96 hour heat treatments at 1200° C. and 1250° C., but again not for 1737 glass.
[0080] The surface crystallization test of FIGS. 7C and 7D provides a convenient way to identify devitrification sensitive glasses. Thus, in general terms, a devitrification sensitive glass is one which forms surface crystals when heat treated for 8 days at 1300° C. Using this test, EAGLE 2000 is a devitrification sensitive glass, while 1737 is not.
[0081] Although the experiments of FIGS. 5 - 7 are specifically concerned with EAGLE 2000 and 1737 glass, the results observed are generally applicable to other glass compositions and, in particular, to other devitrification-sensitive aluminoborosilicate glasses used to produce LCD substrates. The volatility of boron from alkali aluminoborosilicate glasses has been well documented in industrial melting applications. Glass which is stagnant at high temperatures is especially prone to a loss of boron and alkalis to the furnace atmosphere and a subsequent enrichment of the remaining glass in the non-volatile fraction of the composition. The loss of boron and alkalis leads to the formation of a surface layer highly enriched in silica. As the enrichment increases, the composition of this surface layer can migrate below its liquidus leading to the growth of cristobalite.
[0082] The data for 1737 glass set forth in FIGS. 5A, 6A, and 7 , as well as the behavior of this glass during manufacture, shows that although 1737 exhibits some loss of B 2 O 3 and some enrichment of SiO 2 , the magnitude and spatial distribution of these changes for this glass are not sufficient to cause a serious devitrification problem as a result of a stagnant free surface between downcomer 19 and supply pipe 9 . The data of FIGS. 5B, 6B, and 7 for EAGLE 2000, on the other hand, as well as the results of trial manufacturing tests, show that this glass is susceptible to this problem. In general terms, aluminoborosilicate glasses in which the SiO 2 concentration is equal to or greater than 60 wt. % and/or the B 2 O 3 concentration is in the range of 9-10 wt. % or higher are the glasses which will be devitrification sensitive and will require the use of the present invention to address the problem of devitrification defects in the finished glass.
[0083] In outline, the present invention's solution to the devitrification problem for high silica and/or high boron glasses is based on selecting the position of downcomer 19 with respect to molten glass 33 so that the free surface of the molten glass undergoes sufficient activation to avoid levels of SiO 2 enrichment and/or B 2 O 3 depletion that will lead to the production of cristobalite crystals in the finished glass.
[0084] One way of achieving such surface activation is to place the downcomer above nominal free surface 21 N as shown in FIGS. 8 and 9. This creates a free surface 21 which lies above the nominal free surface. The glass which forms free surface 21 is continuously replaced with fresh glass and thus any enrichment of silica and/or depletion of boron oxide that may occur at the surface does not have an opportunity to reach levels where devitrification defects are created in the finished glass. In practice, raising the downcomer above nominal free surface 21 has been found to eliminate devitrification defects of the type shown in FIG. 4 from devitrification sensitive glass.
[0085] However, in accordance with the invention, it has been found that locating the exit end 20 of downcomer 19 above nominal free surface 21 N can itself lead to defects in the finished glass. In this case, the defects are gaseous defects (blister defects) of the type shown in FIG. 10.
[0086] Although not wishing to be bound by any particular theory of operation, it is believed that these defects may be caused by the passage of molten glass over the edge of exit end 20 of downcomer 19 while that edge is exposed to gaseous atmosphere 33 . Because the edge always has some roughness, it can locally deform (locally cut) the molten glass. As those deformations heal, they can entrap small amounts of the gaseous atmosphere (small bubbles of gas) which are unable to escape from the molten glass and thus end up as blister defects in the finished glass. Another possible mechanism for the formation of blister defects is folding or lapping of the molten glass as it exits the downcomer. This effect usually requires a substantial elevation of the exit end of the downcomer above the nominal free surface of the molten glass.
[0087] Although on their face, these blister defects are plainly a problem, from an operational point of view, they are an advantage of the invention. This is so because they provide a procedure for identifying a desirable location for the exit end of the downcomer relative to the nominal free surface of the molten glass.
[0088] In accordance with this procedure, one can begin the search for a suitable location for the exit end of the downcomer with the exit end being, for example, in a submerged condition which produces devitrification defects in a devitrification sensitive glass. (The exit end of the downcomer can, of course, be at a higher location at the beginning of the search procedure based on the teachings herein.) The downcomer is then moved upward until blister defects appear in the finished glass. At this location, the problem of devitrification defects will be eliminated, although, of course, the problem of blister defects will exist. Then, the downcomer is moved downward until the blister defects disappear in the finished glass. In practice, it has been found that this location (or even some further downward movement) does not result in the reappearance of devitrification defects in devitrification sensitive glass. Accordingly, in this way, both devitrification defects and blister defects are effectively eliminated from devitrification sensitive glasses.
[0089] The downward movement of the downcomer to eliminate blister defects can bring the exit end of the downcomer into a location where it is essentially at the free surface, as illustrated in FIGS. 11 and 12, or even below the free surface, e.g., below the free surface by approximately 5 millimeters. Although fresh glass does not overflow the free surface when the exit end of the downcomer is submerged, the free surface can still be sufficiently activated through mechanical and/or diffusional forces to avoid the formation of devitrification defects.
[0090] Although the at-the-free-surface or the below-the-free-surface configurations can be used, the non-submerged configuration of FIGS. 8 and 9 is preferred, provided the spacing between the exit end of the downcomer and the nominal free surface of the molten glass is not too great. In practice, a spacing of 10-30 millimeters, preferably 15-25 millimeters, e.g., approximately 20 millimeters, has been found to work successfully. It is to be understood that these are representative spacings, with the particular spacing used for any specific application of the invention being a function of the equipment used, as well as the viscosity of the molten glass. Based on the present disclosure, a suitable spacing for any particular equipment configuration and molten glass viscosity can be readily determined by persons skilled in the art.
[0091] Although specific embodiments of the invention have been described and illustrated, it is to be understood that modifications can be made without departing from the invention's spirit and scope. For example, the above procedures for identifying a desirable location for the exit end of the downcomer need not be used each time a fusion process is put into operation, but rather knowledge from prior use of the invention can be employed to immediately set the downcomer at a desired location without repeating the procedures which identified that location. Similarly, although the most valuable applications of the invention are in the manufacture of devitrification sensitive glasses by the fusion process, the invention can also be used with glasses that are not devitrification sensitive with no adverse effects and potentially beneficial effects in expanding the operating range of the process.
[0092] A variety of other modifications which do not depart from the scope and spirit of the invention will be evident to persons of ordinary skill in the art from the disclosure herein. The following claims are intended to cover the specific embodiments set forth herein as well as such modifications, variations, and equivalents. | A molten glass delivery system for use in producing sheet glass by a fusion process is provided. The delivery system includes a first conduit ( 9 ) which surrounds a portion of a second conduit ( 19 ) with a free surface ( 21 ) of molten glass ( 31 ) being formed between the two conduits. The first ( 9 ) and second ( 19 ) conduits are positioned with respect to one another so that the spatial relationship between the exit end ( 20 ) of the second conduit ( 19 ) and the free surface ( 21 ) results in neither substantial numbers of devitrification defects ( 27, 29 ) nor substantial numbers of blister defects ( 35 ) in finished sheets of devitrification sensitive glass, e.g., high silica LCD glass. | 8 |
This is a division of application Ser. No. 08/627,281 filed Apr. 4, 1996, now U.S. Pat. No. 6,305,069.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an oxide superconducting wire and a method of preparing the same, and a cable conductor which is formed by assembling such oxide superconducting wires, and more particularly, it relates to an oxide superconducting wire which can carry a heavy current in ac application and a method of preparing the same, and a cable conductor which is formed by assembling such oxide superconducting wires.
2. Description of the Background Art
The principal feature of an oxide superconductor resides in that the same is in a superconducting state also at a temperature exceeding the liquid nitrogen temperature. Therefore, a wire consisting of such an oxide superconductor is expected for application to a superconducting device, as a material which can be used under cooling with liquid nitrogen.
The inventors have developed a tape-shaped Bi-based Ag-coated multifilamentary wire, which is prepared from filaments of an oxide superconductor with a stabilizer of silver. A Bi-based Ag-coated wire can be prepared by charging a metal pipe with raw material powder serving as a precursor for a Bi oxide superconductor, wire-drawing the pipe and thereafter repeating rolling and a heat treatment a plurality of times.
On the other hand, a multifilamentary wire can be prepared by charging metal pipes with raw material powder, wire-drawing the same, engaging a plurality of such wires in a metal pipe for forming a multi-filamentary substance, further wire-drawing the same and thereafter repeating rolling and a heat treatment a plurality of times.
Among such preparation steps, the rolling step is effective for improving the orientation of crystal grains in the Bi superconductor having a plate-type crystal structure, strengthening bonding between the crystal grains and improving the density of the filaments, and regarded as being indispensable for attaining a high critical current density in preparation of a Bi-based Ag-coated wire.
Further, the aspect ratio of a section of the wire is increased by this rolling, whereby the aspect ratio of a section of each filament is also increased. This is advantageous for growth of the plate-type crystals, and a high critical current density is consequently attained.
On the other hand, the heat treatment step for the purpose of sintering is also indispensable for forming the superconductor, attaining crystal growth and strengthening bonding between the crystal grains, since the oxide superconductor is ceramics.
The Bi-based Ag-coated wire which is prepared in the aforementioned manner is excellent in bending property and capable of preparing a long wire having a critical current density exceeding 10 4 A/cm 2 , and hence the same is expected for application to a superconducting cable or magnet.
In ac application of such an oxide superconducting wire, however, ac loss resulting from a fluctuating magnetic field in driving comes into question. In a cable conductor which is formed by assembling superconducting wires, on the other hand, there arises a new problem to be solved such as a drift phenomenon resulting from ununiformity between impedances of the wires, which cannot be caused in dc application. Due to a drift caused in such a manner, further, loss upon formation of the conductor is disadvantageously increased beyond the sum of ac loss values of strands.
As to such problems caused in ac application, various countermeasures have generally been studied in relation to metal superconducting wires, for example. In more concrete terms, countermeasures of arranging high resistance barrier layers around or between filaments, preparing an extra-fine multifilamentary wire from superconducting filaments, increasing the specific resistance of a matrix and the like are studied in order to reduce ac loss. In order to suppress a current drift by uniformalizing the impedances of the filaments or wires in a conductor for an ac magnet, on the other hand, countermeasures of twisting the filaments or wires, dislocating the wires or filaments and the like are studied.
In order to attain a heavy current, further, a countermeasure of further twisting primary stranded wires each prepared by twisting superconducting strands to attain a flat-molded multinary structure or the like is studied.
While a countermeasure of further twisting primarily stranded wires to attain a multinary structure or the like must be taken also in employment of the aforementioned Bi-based Ag-coated wire for ac application similarly to the metal superconducting wire, however, it is impossible to implement the aforementioned multinary structure through an oxide superconducting wire by a method which is absolutely identical to that for the metal superconducting wire. This is because a Bi-based Ag-coated multifilamentary wire indispensably requires rolling and sintering processes as described above, while no such rolling and sintering steps are required for preparing a metal superconducting wire.
Namely, it is difficult to twist wires of a Bi oxide superconductor after sintering, since the Bi oxide superconductor is ceramics which is weak against bending distortion. Even if such wires can be twisted, a high critical current density cannot be attained. Further, it is difficult to twist wires in which aspect ratios of sections are increased by rolling. Even if such wires can be twisted, a number of clearances are defined in the stranded wire as compared with that prepared by twisting round wires, and a high critical current density cannot be attained.
SUMMARY OF THE INVENTION
In order to solve the aforementioned problems, an object of the present invention is to provide an oxide superconducting wire which maintains a high critical current density and has a small current drift with small ac loss when the same carries an alternating current and a method of preparing the same, and a cable conductor which is formed by assembling such oxide superconducting wires.
According to an aspect of the present invention, an oxide superconducting wire is provided. This oxide superconducting wire is a flat-molded stranded wire which is formed by twisting a plurality of metal-coated strands consisting of an oxide superconductor, and is characterized in that the flat-molded stranded wire has a rectangular sectional shape, and a section of each strand forming the flat-molded stranded wire has an aspect ratio of at least 2.
Throughout the specification, the term “aspect ratio” indicates the ratio of the thickness to the width in a cross section of the oxide superconducting wire.
Superconducting filaments provided in the strands can be brought into flat shapes having a high aspect ratio by setting the strands at an aspect ratio of at least 2. Consequently, a superconducting wire having a high critical current density can be obtained. In particular, the aspect ratio of the superconducting filaments is preferably around 10. The section of each strand preferably has an aspect ratio of not more than 20. It is difficult to increase the aspect ratio of the strands beyond 20 in case of twisting and molding the same.
According to the present invention, the strands are completely dislocated due to the twisting, whereby the impedances of the strands forming the stranded wire can be equalized to each other.
According to the present invention, further, the stranded wire has a rectangular sectional shape. Thus, the wire can be densely wound to be advantageously compacted when the same is applied to a coil or a cable.
Preferably, the metal coatings of the strands consist of silver or a silver alloy, and coating layers consisting of a material having higher resistance than silver are provided on the outer peripheries of the metal coatings.
Due to the presence of such coating layers, the strands can be prevented from bonding in the stranded wire, so that ac loss is effectively reduced.
The material having higher resistance than silver is prepared from a high resistance metal material or an inorganic insulating material, for example.
When no such coating layers consisting of a material having higher resistance than silver such as a high resistance metal material or an inorganic insulating material are present, metal matrices of silver or the like are so diffused during the heat treatment that the strands are disadvantageously bonded with each other, and hence bonding loss between the strands may be increased. The coating layers having higher resistance than silver effectively function to reduce such bonding loss.
The high resistance material is prepared from an Ag—Mn alloy, an Ag—Au alloy, or Ni or Cr having high resistance, for example.
On the other hand, the inorganic insulating material is prepared from an oxide insulating material such as MgO or CuO which is obtained by oxidizing Mg or Cu, for example. Bonding between the strands can be completely prevented by the coating layers consisting of such an insulating material. Further, the effect of dislocation is rendered further complete.
According to another aspect of the present invention, a method of preparing an oxide superconducting wire is provided. This method comprises the steps of preparing a stranded wire by twisting a plurality of strands each formed by metal-coating an oxide superconductor or raw material powder therefor, flat-molding the prepared stranded wire, and repeating rolling and a heat treatment of at least 800° C. on the flat-molded stranded wire a plurality of times.
Namely, a plurality of round wire type strands each formed by metal-coating an oxide superconductor or raw material powder therefor, which are not sintered as wires, are prepared. Then, the plurality of strands are twisted for preparing a stranded wire. As to the number of twisted strands, three, seven or twelve strands can be twisted, for example.
This stranded wire is flat-molded and thereafter further rolled, whereby superconducting filaments having circular sections which are provided in the strands can be deformed in the form of flat plates having a high aspect ratio. The dimensions of the superconducting filaments are preferably within the ranges of 0.1 to 100 μm in thickness and 1 μm to 1 mm in width. In the flat-molding, the superconducting filaments can be simultaneously deformed by application of rolling loads from above and under the wire.
Thereafter the step of performing rolling and a heat treatment is carried out at least twice, whereby an oxide superconducting wire in which strands are completely dislocated in order to cope with application to an ac wire can be obtained.
According to the present invention, the respective filaments are subjected to twisting as well as rolling. In the inventive wire, therefore, the impedances of the respective filaments are uniformalized by twisting. Also when the wire carries an alternating current, therefore, the current can be uniformly fed to the respective filaments. Further, bonding currents between the filaments are suppressed for effectively reducing ac loss. When the surfaces of the strands are insulated, it is possible to further suppress the bonding currents and reduce the ac loss.
According to the present invention, the flat-molded stranded wire rolled and heat treated. Thus, a high critical current density can also be attained by strengthening grain bonding which is broken by distortion in formation of the stranded wire and regularizing disturbed orientation.
According to the present invention, further, it is also possible to prepare a flat-molded multinary stranded wire by further twisting a plurality of primary stranded wires each obtained by twisting a plurality of strands. As to the number of twisted stranded wires, nine primary stranded wires can be twisted, for example.
It is particularly important to carry out the twisting step a plurality of times, in order to attain the aforementioned effects when the number of strands which are twisted for the purpose of attaining a high capacitance is increased.
According to the present invention, further, a stranded wire may be prepared by stacking and integrating a plurality of tape-shaped strands with each other and thereafter twisting the same. Particularly in case of a silver sheath Bi 2223 superconducting wire, it is important to prepare tape-shaped strands for attaining a high critical current density. Twisting is simplified by stacking the tape-shaped strands with each other for reducing the aspect ratio of sections thereof and thereafter twisting the same, and characteristic deterioration caused by bending distortion or the like can be effectively prevented.
The strands can be integrated with each other by a method of heat treating the stacked strands and bonding the same with each other by diffusion of silver, a method of performing compression molding, or a method of stacking the strands in a flat pipe, for example. In case of a long wire, it is effective to wire-draw and twist the strands after integrating the same with each other.
The tape-shaped strands are preferably previously heat treated in advance of twisting. It is possible to reinforce grain bonding of the oxide superconductor for attaining a high critical current density by further performing a heat treatment after forming the oxide superconductor by this heat treatment and performing the step of twisting etc.
According to the present invention, the method preferably further comprises a step of previously coating the outer peripheries of the strands with a material having higher resistance than silver before twisting the metal-coated strands for preparing the stranded wire.
The coating layers consisting of a material having higher resistance than silver can be formed by a method of adding Ni or Cr of high resistance to the outer surfaces of the strands by plating, or a method of applying a solution in which powder of an oxide insulating material such as AlO 3 is dispersed to the outer surfaces of the strands, for example.
Alternatively, coating layers consisting of a metal such as Mg or Cu may be formed on the outer peripheries of the strands so that these layers are thereafter oxidized to form coating layers consisting of an oxide insulating material such as MgO or CuO. In particular, excellent workability can be attained by performing an oxidizing step after the rolling of the stranded wire. Mg or Cu is richer in workability than MgO or CuO, and hence the stranded wire can be molded and rolled into a better shape by oxidizing the coating layers after performing twisting and rolling.
According to the present invention, the method preferably further comprises a step of previously coating the flat-molded stranded wire with a metal before rolling.
If the outermost layer of a flat-molded multinary stranded wire is so thin that superconducting filaments may be exposed through the subsequent rolling step, the stranded wire is preferably coated with a metal in advance.
Metal coating layers may be further formed on the outer peripheries of the strands which are coated with a metal such as silver or a silver alloy by performing metal coating on the surface of the flat-molded multinary stranded wire or engagement in a flat metal pipe.
According to the present invention, further, each strand is preferably a multifilamentary wire which is formed by embedding a plurality of superconductors in a metal matrix. Due to a plurality of superconducting filaments provided in each strand, flexibility of the wire is improved.
According to the present invention, the strands themselves are preferably subjected to twisting. Due to such twisting of the strands themselves, bonding loss and eddy current loss are reduced thereby reducing ac loss as a result.
According to the present invention, the method preferably further comprises a step of temporarily heat treating the flat-molded stranded wire before rolling. Workability in rolling can be improved by heat treating the flat-molded stranded wire at about 800° C. for diffusion-bonding the strands with each other.
According to the present invention, further, a step of winding strands around a core of a flat-molded stranded wire and flat-molding the same is preferably repeated a plurality of times.
A wire having low loss and a high capacitance can be obtained by repeating flat-twisting/molding a plurality of times. Such a wire is effective as a material for forming a compact cable conductor having low loss and a high capacitance.
According to still another aspect of the present invention, an oxide superconducting cable conductor is provided. This oxide superconducting cable conductor is formed by assembling oxide superconducting wires on a cylindrical former. Each oxide superconducting wire is a flat-molded stranded wire which is formed by twisting a plurality of metal-coated strands consisting of an oxide superconductor. This flat-molded stranded wire has a rectangular sectional shape, while a section of each strand forming the flat-molded stranded wire has an aspect ratio of at least 2.
In a single-layer cable conductor formed by assembling oxide superconducting wires on a former in a single layer, for example, all strands are dislocated to occupy positions which are electromagnetically completely equivalent to each other, whereby current distribution in the conductor is so uniformalized that increase of ac loss caused by a drift can be prevented. When wires are spirally wound on a former, on the other hand, it is effective to form the conductor in a two-layer structure so that first and second layers are wound in opposite directions, in order to cancel a magnetic field component along the longitudinal direction of the conductor. Thus, a drift between the layers caused by impedance difference therebetween as well as following ac loss can be minimized as compared with a multilayer conductor, by forming the conductor in a single- or two-layer structure.
According to the present invention, as hereinabove described, a metal-coated oxide superconducting wire having a high critical current density which can transmit a current with los loss can be obtained.
According to the present invention, further, it is also possible to increase the critical current per wire beyond 100 A by increasing the number of stranded wires and the degree of twisting, i.e., the number of times of twisting, so that the inventive wire is usefully applied to an oxide superconducting cable or a superconducting magnet which is employed for carrying a high capacitance alternating current.
The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view showing an intermediate in a step of preparing an oxide superconducting wire according to Example 1 of the present invention;
FIG. 2 is a sectional view showing the structure of the oxide superconducting wire according to Example 1 of the present invention;
FIG. 3 is a sectional view showing an intermediate in a step of preparing an oxide superconducting wire according to Example 5 of the present invention;
FIG. 4 is a sectional view showing an intermediate in another step of preparing an oxide superconducting wire according to Example 5 of the present invention;
FIG. 5 is a sectional view showing the structure of another exemplary oxide superconducting wire according to Example 5 of the present invention;
FIG. 6 is a sectional view showing the structure of a strand forming an oxide superconducting wire according to Example 6 of the present invention;
FIG. 7 is a sectional view showing the structure of a strand employed for an oxide superconducting wire according to Example 7 of the present invention;
FIG. 8 is a sectional view showing an intermediate in a step of preparing an oxide superconducting wire according to Example 7 of the present invention;
FIG. 9 is a sectional view showing an intermediate in another step of preparing an oxide superconducting wire according to Example 7 of the present invention;
FIG. 10 is a sectional view showing the structure of the oxide superconducting wire according to Example 7 of the present invention;
FIG. 11 is a sectional view showing an intermediate in a step of preparing an oxide superconducting wire according to Example 8 of the present invention;
FIG. 12 is a sectional view showing the structure of the oxide superconducting wire according to Example 8 of the present invention;
FIG. 13 is a perspective view showing the structure of an oxide superconducting cable conductor according to Example 12 of the present invention;
FIG. 14 is a sectional view showing the structure of the oxide superconducting cable conductor according to Example 12 of the present invention; and
FIG. 15 is a sectional view showing the structure of an oxide superconducting wire according to Example 13 of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
EXAMPLE 1
Bi 2 O 3 , PbO, SrCO 3 , CaCO 3 and CuO were blended with each other so that Bi, Pb, Sr, Ca and Cu were in composition ratios of 1.81:0.30:1.92:2.01:3.03. The blended powder was heat treated a plurality of times. This powder was crushed after each heat treatment. The powder obtained through such a heat treatment and crushing was further crushed by a ball mill, to obtain submicron powder.
Precursor powder obtained in the aforementioned manner was heat treated at 800° C. for 2 hours, and thereafter charged in a silver pipe of 12 mm in outer diameter and 8 mm in inner diameter. Then, the silver pipe charged with the powder was drawn into 0.9 mm, to prepare strands. Seven such strands were twisted to prepare the so-called primary stranded wire. Further, 15 such primary stranded wires were twisted and thereafter compression-molded, for preparing a flat-molded secondary stranded wire.
FIG. 1 is a sectional view showing the structure of the secondary stranded wire prepared in the aforementioned manner. Referring to FIG. 1, 15 primary stranded wires 12 each formed by twisting seven strands 11 are further twisted.
Then, the secondary stranded wire was heat treated at 800° C. for 2 hours so that the strands were integrated with each other by diffusion bonding, and thereafter rolled. Then, the stranded wire was heat treated at 845° C. for 50 hours, further rolled and thereafter heat treated at 840° C. for 50 hours.
FIG. 2 is a sectional view showing the structure of an oxide superconducting wire obtained in the aforementioned manner. Referring to FIG. 2, the flat-molded stranded wire has a rectangular sectional shape in this wire, and each strand 11 has a flat section having an aspect ratio (W1/T1) of about 4.
Then, the oxide superconducting wire obtained in the aforementioned manner was subjected to measurement of a critical current value Ic in liquid nitrogen. Consequently, this wire exhibited a value Ic of 50 A.
Ac loss values of a multilayer conductor which was formed by stacking five Bi-based Ag-coated single-filamentary wires having a critical current value Ic of 10 A and the inventive wire were measured by an energization four-probe method. Consequently, it has been confirmed that the ac loss of the inventive wire was smaller than that of the multilayer conductor in a region of not more than 50 Ap.
EXAMPLE 2
Precursor powder having a composition equal to that of the precursor powder employed in Example 1, which was obtained similarly to Example 1, was heat treated at 800° C. for 2 hours, and thereafter charged in a silver pipe of 12 mm in outer diameter and 9 mm in inner diameter. Then, the silver pipe charged with the powder was drawn into 0.9 mm, to prepare strands. Seven such strands were twisted to form the so-called primary stranded wire. Further, 15 such primary stranded wires were twisted and thereafter compression-molded, to prepare a flat-molded secondary stranded wire.
Then, the secondary stranded wire was engaged in a flat silver pipe of 1 mm in thickness, subjected to diffusion bonding at 800° C. for 2 hours, and thereafter rolled. Then, the pipe was heat treated at 845° C. for 50 hours, further rolled and thereafter heat treated at 840° C. for 50 hours.
In the structure of an oxide superconducting wire obtained in the aforementioned manner, the flat-molded stranded wire had a rectangular sectional shape, and each strand had a flat section having an aspect ratio of about 4, similarly to Example 1.
Then, the oxide superconducting wire obtained in the aforementioned manner was subjected to measurement of a critical current value Ic in liquid nitrogen. Consequently, this wire exhibited a value Ic of 50 A.
Ac loss values of a multilayer conductor which was formed by stacking five Bi-based Ag-coated single-filamentary wires having a critical current value Ic of 10 A and the inventive wire were measured by an energization four-probe method. Consequently, it has been confirmed that the ac loss of the inventive wire was smaller than that of the multilayer conductor in a region of not more than 50 Ap.
EXAMPLE 3
Precursor powder having a composition equal to that of the precursor powder employed in Example 1, which was obtained similarly to Example 1, was heat treated at 800° C. for 2 hours, and thereafter charged in a silver pipe of 12 mm in outer diameter and 9 mm in inner diameter. Then, the silver pipe charged with the powder was drawn into 0.9 mm, and seven such wires were engaged in a silver pipe and drawn to prepare a seven-conductor multifilamentary wire. Further, the seven-conductor multifilamentary wire was twisted at a pitch of 20 mm. Seven strands consisting of such twisted seven-conductor multifilamentary wires were twisted, to prepare the so-called primary stranded wire. Further, 15 such primary stranded wires were twisted and thereafter compression-molded, to prepare a flat-molded secondary stranded wire.
Then, this secondary stranded wire was engaged in a flat silver pipe of 1 mm in thickness, subjected to diffusion bonding at 800° C. for 2 hours, and thereafter rolled. Then, the pipe was heat treated at 845° C. for 50 hours, further rolled and thereafter heat treated at 840° C. for 50 hours.
In the structure of an oxide superconducting wire obtained in the aforementioned manner, the flat-molded stranded wire had a rectangular sectional shape similarly to Example 1, and each strand had a flat section having an aspect ratio of about 5.
Then, the oxide superconducting wire obtained in the aforementioned manner was subjected to measurement of a critical current value Ic in liquid nitrogen. Consequently, the inventive wire exhibited a value Ic of 40 A.
Ac loss values of a multilayer conductor which was formed by stacking four Bi-based Ag-coated single-filamentary wires having a critical current value Ic of 10 A and the inventive wire were measured by an energization four-probe method. Consequently, it has been confirmed that the ac loss of the inventive wire was smaller than that of the multilayer conductor in a region of not more than 40 Ap.
EXAMPLE 4
Precursor powder having a composition equal to that of the precursor powder employed in Example 1, which was obtained similarly to Example 1, was heat treated at 800° C. for 2 hours, and thereafter charged in a silver pipe of 12 mm in outer diameter and 10 mm in inner diameter. Seven such silver pipes charged with the powder were drawn and further engaged in a silver pipe of 12 mm in outer diameter and 9 mm in inner diameter to form a seven-conductor wire, which in turn was drawn into 0.9 mm.
Seven strands consisting of seven-conductor wires obtained in the aforementioned manner were twisted to prepare the so-called primary stranded wire. Further, 15 such primary stranded wires were twisted and thereafter compression-molded, to prepare a flat-molded secondary stranded wire.
Then, this secondary stranded wire was engaged in a flat silver pipe of 1 mm in thickness, which in turn was rolled, heat treated at 845° C. for 50 hours, further rolled and thereafter heat treated at 840° C. for 50 hours.
In the structure of an oxide superconducting wire obtained in the aforementioned manner, the flat-molded stranded wire had a rectangular sectional shape similarly to Example 1, and each strand had a flat section having an aspect ratio of about 5.
Then, the oxide superconducting wire obtained in the aforementioned manner was subjected to measurement of a critical current value Ic in liquid nitrogen. Consequently, this wire exhibited a value Ic of 40 A.
Ac loss values of a multilayer conductor which was formed by stacking four Bi-based Ag-coated single-filamentary wires having a critical current value Ic of 10 A and the inventive wire were measured by an energization four-probe method. Consequently, it has been confirmed that the ac loss of the inventive wire was smaller than that of the multilayer conductor in a region of not more than 40 Ap.
EXAMPLE 5
Precursor powder having a composition equal to that of the precursor powder employed in Example 1, which was obtained similarly to Example 1, was heat treated at 800° C. for 2 hours, and thereafter charged in a silver pipe of 24 mm in outer diameter and 20 mm in inner diameter. Then, 61 such silver pipes charged with the powder were drawn into diameters of 1.02 mm and further engaged in a silver pipe of 24 mm in outer diameter and 20 mm in inner diameter, which in turn was further drawn into a diameter of 1.02 mm, to form a strand. 12 such strands were twisted and flat-molded.
FIG. 3 is a sectional view showing the structure of a flat-molded stranded wire 52 obtained in the aforementioned manner. Referring to FIG. 3, this stranded wire 52 had a width W2 of 7.4 mm, and a thickness T2 of 1.45 mm.
Then, this wire was rolled into a thickness of 1 mm, and thereafter heat treated at 845° C. for 50 hours. Then the wire was rolled into 0.9 mm, and thereafter heat treated at 840° C. for 50 hours.
FIG. 4 is a sectional view showing the structure of a reacted flat-molded stranded wire 58 according to the present invention obtained in the aforementioned manner.
Referring to FIG. 4, this stranded wire 58 had a width W2 of 12 mm, and a thickness T1 of 1 mm. Each strand 51 forming the stranded wire 58 had an aspect ratio (W1/T1) of 4.4. As a result of a detailed analysis, each superconducting filament provided in each strand 51 had a width of about 100 μm and a thickness of about 10 μm. The volume percentage of a Bi 2223 phase was about 95%. Further, this superconducting flat-molded stranded wire had a critical current value Ic of 110 A.
Throughout the specification, the term “volume percentage” indicates the ratio of a magnetization rate exhibited by each sample in practice with respect to a magnetization rate (−{fraction ( 1 / 4 )}π [emU/cc]) which is measured when a superconductor exhibits complete diamagnetism.
FIG. 5 is a sectional view showing the structure of another exemplary oxide superconducting wire 152 after rolling. The superconducting wire 152 having absolutely no clearances between strands 151 can be obtained by rolling the same under a condition of setting a draft at 30 to 40% while providing guides on both sides thereof.
As comparative example, a substance obtained by engaging 61 conductors and thereafter drawing the same into a diameter of 1.02 mm similarly to the aforementioned wire was rolled into a thickness of 0.25 mm, and heat treated at 845° C. for 50 hours to prepare a wire. Four such wires were stacked, rolled into a thickness of 0.9 mm and heat treated at 840° C. for 50 hours, to be subjected to measurement of a critical current value Ic. Consequently, this comparative example exhibited a value Ic of 100 A.
Further, ac loss values of the aforementioned two types of wires were measured by an energization four-probe method. Consequently, the ac loss of the flat stranded wire was 0.05 mW/m while that of comparative example was 0.5 mW/m in energization under 60 Hz and 20 A rms . Thus, it has been recognized that the ac loss was reduced to {fraction (1/10)} in the inventive wire.
EXAMPLE 6
Cr or Ni was plated on the surfaces of the strands prepared in Example 5. 12 such strands were twisted and flat-molded. After the molding, the stranded wire had a width of 7.4 mm and a thickness of 1.45 mm. This wire was rolled into a thickness of 1 mm, and thereafter heat treated at 845° C. for 50 hours. Thereafter the wire was rolled into 0.9 mm, and thereafter heat treated at 840° C. for 50 hours.
FIG. 6 is a sectional view showing the structure of each strand 61 forming the flat-molded stranded wire obtained in the aforementioned manner.
Referring to FIG. 6, this strand 61 had a flat shape at an aspect ratio (W1/T1) of 3.7, and comprised a coating layer 66 consisting of Cr or Ni plating on its outer periphery. Further, the strand 61 was formed by embedding 61 superconductor filaments 65 in a matrix 64 consisting of silver, and each filament 65 had a width W5 of about 90 μm and a thickness T5 of about 10 μm.
The arrangement of the filaments 65 shown in FIG. 6 is a mere example, and the present invention is not necessarily restricted to such arrangement.
The volume percentage of a Bi 2223 phase was about 95%, and the critical current value Ic was 105 A.
Ac loss of this wire which was measured by an energization four-probe method was 0.01 mW/m in energization under 20 A. Thus, it has been recognized that the ac loss was reduced to ⅕ as compared with the strand of Example 1.
EXAMPLE 7
Precursor powder having a composition equal to that of the precursor powder employed in Example 1, which was obtained similarly to Example 1, was charged in a silver pipe of 24 mm in outer diameter and 20 mm in inner diameter. 61 such silver pipes were drawn into diameters of 1.02 mm and engaged in an Ag—Mn alloy pipe of 24 mm in outer diameter and 20 mm in inner diameter, which in turn was drawn into a diameter of 1.02 mm. Thereafter this wire was twisted at a pitch of 25 mm and thereafter rolled into a width of 3 mm and a thickness of 0.25 mm, to prepare a tape-shaped strand.
FIG. 7 is a sectional view showing the structure of a tape-shaped strand 71 obtained in the aforementioned manner. Referring to FIG. 7, this strand 71 is formed by embedding 61 superconducting filaments 75 in a matrix 74 consisting of silver, and a coating layer 76 consisting of an Ag—Mn alloy is formed on its outer periphery.
Then, 12 tape-shaped strands 71 obtained in the aforementioned manner were stacked as shown in FIG. 8, and heat treated at 840° C. for 50 hours. Thus, a multilayer wire 77 obtained in this manner was flat-drawn so that each side was 1 mm, and thereafter four such wires were twisted and flat-molded as shown in FIG. 9 . In the molding, the thickness was reduced by 10%. This wire was heat treated at 840° C. for 50 hours.
FIG. 10 is a sectional view showing the structure of an oxide superconducting wire obtained in the aforementioned manner. Referring to FIG. 10, this wire is a flat-molded stranded wire formed by twisting four multilayer wires 77 .
Then, the oxide superconducting wire obtained in the aforementioned manner was subjected to measurement of a critical current value Ic in liquid nitrogen. Consequently, this wire exhibited a value Ic of 50 A.
In this oxide superconducting wire, each superconducting filament had a width of about 30 μm and a thickness of about 3 μm.
Further, ac loss values of the flat-molded stranded wire obtained in the aforementioned manner and a 61-conductor wire having a critical current value Ic of 50 A, which was obtained by engaging 61 conductors and thereafter drawing, rolling and heat treating the same similarly to comparative example prepared in relation to Example 5, were measured by an energization four-probe method. Consequently, the ac loss of the flat stranded wire was 0.1 mW/m while that of comparative example was 4 mW/m in energization under 20 A peak . Thus, it has been recognized that the ac loss was reduced to {fraction (1/40)} in the inventive wire.
EXAMPLE 8
The tape-shaped wire 71 shown in FIG. 7 employed in Example 7 was heat treated at 845° C. for 50 hours, and thereafter rolled into a thickness of 0.2 mm. Then, Cr plating was performed on its surface. Then, 12 strands 81 having Cr-plated surfaces were stacked and inserted in a silver flat pipe 86 , as shown in FIG. 11. A multilayer wire 87 obtained in this manner was flat-drawn so that each side was 1 mm, and 12 such wires were further twisted and flat-molded. This wire was heat treated at 840° C. for 50 hours.
FIG. 12 is a sectional view showing the structure of an oxide superconducting wire obtained in the aforementioned manner. Referring to FIG. 12, this wire is a flat-molded stranded wire formed by twisting 12 multilayer wires 87 .
Then, the oxide superconducting wire obtained in the aforementioned manner was subjected to measurement of a critical current value Ic in liquid nitrogen. Consequently, this wire exhibited a value Ic of 150 A.
In this oxide superconducting wire, each superconducting filament had a width of about 30 μm and a thickness of about 3 μm.
Further, ac loss values of the flat-molded stranded wire obtained in the aforementioned manner and a wire obtained by stacking two 61-conductor wires having a critical current value Ic of 70 A, each of which was obtained by engaging 61 conductors, and thereafter drawing, rolling and heat treating the same similarly to comparative example prepared in relation to Example 5, were measured by an energization four-probe method. Consequently, the ac loss of the flat stranded wire was 0.2 mW/m while that of comparative example was 4 mW/m in energization under 20 A peak . Thus, it has been recognized that the ac loss was reduced.
EXAMPLE 9
Two types of wires were prepared by plating surfaces of strands of 1.02 mm in diameter prepared in Example 5 with Mg and Cu in thicknesses of 10 μm. Then, 12 such strands were twisted and flat-molded similarly to Example 1, and thereafter subjected to rolling and a heat treatment twice to form an oxide superconducting flat-molded stranded wire.
In the superconducting wires obtained in this manner, Cu on the surfaces of strands was oxidized into CuO while Mg was also oxidized into MgO by the heat treatment which was repeated twice. Consequently, the strands were substantially completely insulated from each other.
Then, a critical current value Ic in liquid nitrogen was measured as to the oxide superconducting wire obtained in the aforementioned manner. Consequently, this wire exhibited a value Ic of 98 A. Thus, it is understood that Cu or Mg is entirely is oxidized in the heat treatment so that only oxide films of CuO or MgO are formed on the strand surfaces when the Mg or Cu plating films formed on the strand surfaces are sufficiently reduced in thickness. Thus, it has been confirmed that the superconductivity of the wire was not influenced by Mg or Cu in this case.
Further, ac loss was measured as to the oxide superconducting wire obtained in the aforementioned manner. Consequently, ac loss in energization under 20 A peak was 0.01 mW/m in the case of forming CuO films on the strand surfaces, and 0.02 mW/m in the case of forming MgO films on the strand surfaces. Thus, it has been confirmed that bonding loss between the strands could be extremely reduced in both cases.
EXAMPLE 10
A solution which was prepared by dispersing alumina powder in an organic solvent was applied to the surfaces of the strands of 1.02 mm in diameter prepared in Example 5. Then, 12 such strands were twisted and flat-molded similarly to Example 1, and thereafter subjected to rolling and a heat treatment twice to prepare an oxide superconducting flat-molded stranded wire.
In the superconducting wire obtained in the aforementioned manner, alumina was uniformly dispersed in the surfaces of the strands by the heat treatment which was repeated twice. Consequently, the strands were substantially completely insulated from each other.
Then, the oxide superconducting wire obtained in the aforementioned manner was subjected to measurement of a critical current value Ic in liquid nitrogen. Consequently, this wire exhibited a value Ic of 89 A.
Further, ac loss was measured as to the oxide superconducting wire obtained in the aforementioned manner. Consequently, ac loss in energization under 20 A peak was 0.02 mW/m, and it has been confirmed that bonding loss between the strands could be extremely reduced.
EXAMPLE 11
Strands and a flat-molded stranded wire were prepared under conditions absolutely similar to those of Example 5, except that an Ag—Mn or Ag—Au alloy pipe was employed as a sheath material in place of the silver pipe. The obtained superconducting wire was subjected to measurement of a critical current value Ic in liquid nitrogen and ac loss under 51 Hz and 20 A peak . Table 1 shows results of comparison of characteristics.
TABLE 1
Comparative
Example
Example
Example
Example 5
Example 6
11
11
Sheath
Ag
Ag
Ag
Ag-Mn
Ag-Au
Material
(Matrix)
High
no
no
Cr, Ni
no
no
Resistance
Phase
Structure
four
flat-
flat-
flat-
flat-
stacked
molded
molded
molded
molded
layers
Ic
100A
110A
105A
90A
108A
AC Loss
0.5
0.05
0.01
0.03
0.02
(51 Hz,
mW/m
mW/m
mW/m
mW/m
mW/m
20 A peak)
Referring to Table 1, it has been recognized that bonding loss between strands is considerably reduced and ac loss is consequently reduced when a silver alloy of high resistance is employed for metal coatings of the strands.
EXAMPLE 12
FIG. 13 is a perspective view showing the structure of an exemplary oxide superconducting cable conductor according to the present invention, and FIG. 14 is a sectional view thereof.
Referring to FIGS. 13 and 14, this oxide superconducting cable conductor is formed by spirally assembling oxide superconducting wires 58 of Example 5 shown in FIG. 4 on a Cu pipe 9 in two layers. The first and second layers are assembled in S twist (anticlockwise) and Z twist (clockwise) respectively. The oxide superconducting cable conductor obtained in this manner was subjected to measurement of a critical current value Ic in liquid nitrogen. Consequently, this cable conductor exhibited a value Ic of 1500 A.
For the purpose of comparison, four layers of 61-conductor wires having a critical current value Ic of 25 A, each of which was obtained by engaging 61 conductors and thereafter drawing, rolling and heat treating the same similarly to the comparative wire prepared in relation to Example 5, were assembled on a Cu pipe of the same size as the above, to prepare a cable conductor having a critical current value Ic of 1500 A. Ac loss values were measured as to these two cable conductors. Consequently, the stranded wire two-layer conductor according to the present invention exhibited a value which was smaller by two digits than that of the four-layer conductor of comparative example.
EXAMPLE 13
The flat-molded stranded wire 52 prepared in Example 5 as shown in FIG. 3, which was not yet rolled and heat treated, was employed as a core so that 16 strands 51 employed in Example 5 were wound on its periphery, and flat-molded. This wire was rolled into a thickness of 2 mm, and thereafter heat treated at 845° C. for 50 hours. Then the wire was rolled into a thickness of 1.9 mm, and thereafter heat treated at 840° C. for 50 hours.
FIG. 15 is a sectional view showing the structure of the oxide superconducting wire obtained in the aforementioned manner.
Then, the oxide superconducting wire obtained in the aforementioned manner was subjected to measurement of a critical current value Ic in liquid nitrogen. Consequently, this wire exhibited a value Ic of 230 A.
In this oxide superconducting wire, each superconducting filament had a width of about 110 μm, and a thickness of 9 μm.
As comparative example, 10 wires each obtained by engaging 61 conductors and thereafter drawing, rolling and heat treating the same similarly to Example 5 were stacked, rolled into a thickness of 2 mm and heat treated at 840° C. for 50 hours, to be subjected to measurement of a critical current value Ic. Consequently, this wire exhibited a value Ic of 250 A.
Further, ac loss values of the aforementioned two types of wires were measured by an energization four-probe method. Consequently, the ac loss of the flat stranded wire was 0.3 mW/m while that of comparative example was 2 mW/m in energization under 100 A rms . Thus, it has been recognized that the ac loss was reduced.
EXAMPLE 14
The flat-molded stranded wire prepared in Example 6 was employed to prepare an oxide superconducting cable conductor having the same structure as Example 12. The obtained oxide superconducting cable conductor exhibited a critical current value Ic of 1400 A in liquid nitrogen. Further, this conductor exhibited ac loss which was lower by 100% than that of the cable conductor according to Example 12.
Although the present invention has been described and illustrated in detail, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, the spirit and scope of the present invention being limited only by the terms of the appended claims. | Provided are an oxide superconducting wire which maintains a high critical current density and has a small current drift with small ac loss when the same carries an alternating current and a method of preparing the same, and a cable conductor which is formed by assembling such oxide superconducting wires. The oxide superconducting wire is a flat-molded stranded wire which is formed by twisting a plurality of metal-coated strands consisting of an oxide superconductor, and is characterized in that the flat-molded stranded wire has a rectangular sectional shape, and a section of each strand forming the flat-molded stranded wire has an aspect ratio (W1/T1) of at least 2. The method of preparing this oxide superconducting wire comprises the steps of preparing a stranded wire by twisting a plurality of strands, each of which is formed by metal-coating an oxide superconductor or raw material powder therefor, flat-molding the prepared stranded wire, and repeating rolling and a heat treatment of at least 800° C. on the flat molded stranded wire a plurality of times. | 8 |
[0001] This Application is a Continuation of U.S. application Ser. No. 10/503,887 filed on Feb. 12, 2003
FIELD OF THE INVENTION
[0002] The following invention relates to improvements in portable printer technology. More particularly, though not exclusively, the invention relates to a capping device for a hand-held drop-on-demand printer having a fixed printhead for ejecting droplets of ink onto a sheet of print media external to the printer.
BACKGROUND
[0003] Prior art drop-on-demand printers incorporate a supply of print media and employ a print media feed mechanism to transport the print media past the printhead or printheads to effect printing onto the print media. Our co-pending application (AP43) entitled “Manually Moveable Printer with Speed Sensor” discloses a portable, hand-held drop-on-demand inkjet printer having a fixed printhead. The printer can print an image onto a sheet external to the printer by passing the casing of the printer over and across the print media as the nozzles of the printhead eject ink.
[0004] During non-use periods of the printer, a capping device seals the printhead from the surrounding atmosphere to prevent evaporation of ink and the consequential blockage of the nozzles.
[0005] The present application is directed to specific capping arrangements for portable printers, particularly, though not exclusively, for portable printers of the type disclosed in co-pending application AP43, the contents of which are specifically incorporated herein by cross-reference.
[0000] Co-Pending Applications
[0006] Various methods, systems and apparatus relating to the present invention are disclosed in the following co-pending applications filed by the applicant or assignee of the present invention simultaneously with the present application:
PCT/AU03/00154 PCT/AU03/00151 PCT/AU03/00150 PCT/AU03/00145 PCT/AU03/00153 PCT/AU03/00152 PCT/AU03/00168 PCT/AU03/00169 PCT/AU03/00170 PCT/AU03/00162 PCT/AU03/00146 PCT/AU03/00159 PCT/AU03/00171 PCT/AU03/00149 PCT/AU03/00167 PCT/AU03/00158 PCT/AU03/00147 PCT/AU03/00166 PCT/AU03/00164 PCT/AU03/00163 PCT/AU03/00165 PCT/AU03/00160 PCT/AU03/00157 PCT/AU03/00148 PCT/AU03/00156 PCT/AU03/00155
The disclosures of these co-pending applications are incorporated herein by cross-reference.
Related Patent Applications and Patents
6566858 6331946 6246970 6442525 PCT/AU01/00141 09/505951 PCT/AU01/00139 6816968 6757832 PCT/AU01/00140 PCT/AU00/00741 6238044 PCT/AU00/00742 6425661 6227652 6213588 6213589 6231163 6247795 6394581 6244691 6257704 6416168 6220694 6257705 6247794 6234610 6247793 6264306 6241342 6247792 6264307 6254220 6234611 6302528 6283582 6239821 6338547 6247796 6557977 6390603 6362843 6293653 6312107 6227653 6234609 6238040 6188415 6227654 6209989 6247791 6336710 6217153 6416167 6243113 6283581 6247790 6260953 6267469 6273544 6309048 6420196 6443558 6439689 6378989 6848181 6634735 PCT/AU98/00550 PCT/AU00/00095 6390605 6322195 6612110 6480089 6460778 6305788 PCT/AU00/00172 6426014 PCT/AU00/00338 6364453 PCT/AU00/00339 6457795 PCT/AU00/00581 6315399 PCT/AU00/00580 6338548 PCT/AU00/00582 6540319 PCT/AU00/00587 6328431 PCT/AU00/00588 6328425 PCT/AU00/00589 6991320 PCT/AU00/00341 6595624 PCT/AU00/00340 PCT/AU00/00749 6417757 PCT/AU01/01332 7095309 PCT/AU01/01318 6854825 PCT/AU00/00750 7075677 PCT/AU00/00751 6428139 PCT/AU00/00752 6575549 PCT/AU01/00502 PCT/AU00/00583 6383833 PCT/AU02/01120 PCT/AU00/00593 6464332 PCT/AU00/00333 PCT/AU00/01513 6428142 PCT/AU00/00590 6390591 PCT/AU00/00591 7018016 PCT/AU00/00592 6328417 PCT/AU00/00584 6322194 PCT/AU00/00585 6382779 PCT/AU00/00586 6629745 PCT/AU00/01514 6565193 PCT/AU00/01515 6609786 PCT/AU00/01516 6609787 PCT/AU00/01517 6439908 PCT/AU00/01512 6684503 PCT/AU00/00753 6755513 PCT/AU00/00594 6409323 PCT/AU00/00595 6281912 PCT/AU00/00596 6604810 PCT/AU00/00597 6318920 PCT/AU00/00598 6488422 PCT/AU01/01321 6655786 PCT/AU01/01322 6457810 PCT/AU01/01323 6485135 PCT/AU00/00516 6795215 PCT/AU00/00517 09/575109 PCT/AU00/00511 6859289 PCT/AU00/00754 6977751 PCT/AU00/00755 6398332 PCT/AU00/00756 6394573 PCT/AU00/00757 6622923
DISCLOSURE OF THE INVENTION
[0051] There is disclosed herein a portable printer comprising:
[0052] a housing,
[0053] a printhead affixed within the housing and including a plurality of ink ejection nozzles configured to eject droplets of ink toward a sheet of print media external to the housing in a printing operational mode, and
[0054] a capping device including an arm having a capping region that covers the ink ejection nozzles when the printer is in a non-printing operational mode and moves away from the nozzles to enable ejection of ink en route to a sheet of print media in said printing operational mode.
[0055] Preferably the arm is attached by a pivot to the housing.
[0056] Preferably the arm includes an activation region to one side of the pivot and a leg to the other side of the pivot, the leg extending in a direction substantially normal to the activation region and including said capping region.
[0057] Preferably an elastomeric pad is attached to the capping region.
[0058] Alternatively the arm is formed of a resilient, elastically deformable material being affixed at an end thereof to the housing.
[0059] In this alternative the housing can include a fulcrum and said arm includes an activation region to one side of said fulcrum and a leg to the other side of the fulcrum, the leg extending in a direction substantially normal to the activation region and including said capping region.
[0060] Alternatively again, the housing can have mounted thereto a wheel by which the housing rides over a sheet of print media in said printing operational mode, the wheel having associated therewith a friction clutch, the friction clutch including activation means for deflecting said capping region of the arm upon rotation of said wheel in said printing operational mode.
[0061] In this alternative said activation means can comprise a peg projecting from the friction clutch.
[0062] In this alternative the arm can be formed from an elastically deformable material including a deviation and wherein the peg bears against the deviation.
[0063] In a further alternative the arm can be attached to the housing by an integral spring and the printer further comprises an eccentric cam upon a shaft, the eccentric cam bearing against the arm and rotatable to deflect the arm so as to move said capping region away from the nozzles to enable ejection of ink in said printing operational mode.
[0064] In yet a further alternative, the printer can include a solenoid within the housing disposed with respect to the arm such that upon energization of the solenoid magnetic force draws the arm thereto so as to move said capping region away from the nozzles to enable ejection of ink in said printing operational mode.
[0065] In this alternative the arm can have attached thereto a metal plate to interact with the solenoid.
[0066] In this alternative the arm can include an integral spring interacting with the solenoid so as to bias the arm away from the solenoid.
BRIEF DESCRIPTION OF THE DRAWINGS
[0067] Preferred forms of the present invention will now be described by way of example only with reference to the accompanying drawings wherein:
[0068] FIG. 1 is a schematic cross-sectional end elevational view of a portable printer showing a first capping device in a capped position;
[0069] FIG. 2 is a schematic cross-sectional end elevational view of the portable printer of FIG. 1 with the first capping device shown in an uncapped position;
[0070] FIG. 3 is a schematic cross-sectional end elevational view of a portable printer having a second type of capping device, in a capped position;
[0071] FIG. 4 is a schematic cross-sectional end elevational view of the printer of FIG. 3 with the second capping device, in an uncapped position;
[0072] FIG. 5 is a schematic cross-sectional end elevational view of a portion of another printer having a third type of capping device, in a capped position;
[0073] FIG. 6 is a schematic cross-sectional elevational view of a portion of the printer of FIG. 5 with the third capping device in an uncapped position;
[0074] FIG. 7 is a schematic front elevational view of a friction clutch used in the embodiment of FIGS. 5 and 6 ;
[0075] FIG. 8 is a schematic cross-sectional end elevational view of a portion of a printer having a fourth type of capping device, in a capped position;
[0076] FIG. 9 is a schematic cross-sectional end elevational view of a portion of the printer of FIG. 8 with the fourth capping device shown in an uncapped configuration;
[0077] FIG. 10 is a schematic cross-sectional end elevational view of a portion of a printer having a fifth type of capping device, in a capped configuration; and
[0078] FIG. 11 is a schematic cross-sectional end elevational view of the portion of the printer of FIG. 10 with the fifth capping device shown in an uncapped configuration.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0079] In the accompanying drawings there are schematically depicted a number of different capping configurations for a portable printer. The portable printer is intended to eject droplets of ink onto a sheet of print media as the printer is held by hand and moved across the sheet of print media. A typical internal configuration of a printhead and associated hardware in a portable printer for which the capping devices disclosed herein are applicable is disclosed in co-pending application entitled “Manually Moveable Printer with Speed Sensor” (AP43) cross-referenced above.
[0080] In FIGS. 1 and 2 of the accompanying drawings there is schematically depicted in cross-section, a printer housing 10 having located therein a fixed printhead 11 . The printhead 11 has a print chip 12 extending throughout its full width, that is, the width of an image to be printed. A first embodiment of a capper arm 13 , which may be metallic or formed of other material such as plastics, is pivotally mounted at 14 to the printer housing 10 . The capper arm 13 resides at the exterior of the housing 10 and includes a leg 28 to which there is affixed an elastomeric pad 16 which seals against the chip 12 in the capped configuration depicted in FIG. 1 . The elastomeric pad 16 is moved away from the print chip 12 by leg 28 to enable printing in the configuration depicted in FIG. 2 .
[0081] The capper arm 13 includes an activating region 15 to which finger force can be applied as indicated by arrow F shown in FIG. 2 . The application of such finger force causes pivoting of the capper arm 13 about pivot 14 . A spring (not shown) can return the capper arm to the position shown in FIG. 1 .
[0082] A second embodiment of the capping device is depicted in FIGS. 3 and 4 . In this embodiment, the capper arm 13 is formed of a resilient, elastically deformable material such as metal or plastics. In a particular preferred embodiment, the capper arm 13 is formed of stainless steel. The capper arm 13 is fixed at 17 to the printer housing 10 at one end thereof A fulcrum 14 (depicted schematically) resides alongside the transition of the capper arm 13 to the leg 29 .
[0083] Upon the application of finger force F as indicated in FIG. 4 , the capper arm 13 deforms, resulting in the leg 29 moving to the position depicted in FIG. 4 so as to draw the elastomeric pad 16 away from the print chip 12 for printing purposes. Upon release of the finger force F, the resilience of the capper returns it to the configuration depicted in FIG. 3 wherein the elastomeric pad 16 seals against the print chip 12 .
[0084] In the first and second embodiments of the capping device shown in FIGS. 1 to 4 , a user grasps the printer housing 10 and in doing so, inherently applies a force F to the activation region 15 of the capper arm 13 . There may be provided a switch within the printer housing and associated with the capper arm 13 such that application of finger force F depresses the switch to set the printhead 11 into a printing operational mode.
[0085] In FIGS. 5 to 7 of the accompanying drawings there is schematically depicted a third embodiment of a capping device incorporating a friction clutch. In this embodiment, the printer housing 10 has mounted thereto one or more wheels 18 , at least one of which can be associated with an optical sensor as described in the cross-referenced application AP 43 entitled “Manually Moveable Printer with Speed Sensor”. One of the wheels, ie. wheel 18 in this example, can have associated with it a friction clutch 19 . Wheel 18 and clutch 19 can be mounted upon a common shaft 30 ( FIG. 7 ) and biased against each other such that rotation of wheel 18 causes rotation of clutch 19 until something stops the clutch 19 from spinning, whereupon wheel 18 continues to rotate with a dynamic frictional engagement between it and the non-rotating clutch 19 . In the embodiment depicted, the friction clutch 19 has a peg 20 extending laterally from it. This peg 20 is received behind a deviated portion 21 of the capper arm 13 . In this embodiment, the capper arm 13 is attached within the printer housing 10 such that portion 29 moves in a linear fashion, ie. it is guided to move in a straight line. Upon rotation of friction clutch 19 , the peg 20 bears against the deviated portion 21 of capper arm 13 to move it in the direction indicated by arrow C ( FIG. 6 ). This, in turn, draws the elastomeric pad 16 away from the chip 12 . It should be appreciated in this regard that wheel 18 is riding upon the print media 22 to effect wheel rotation in the direction indicated by arrow W in FIG. 6 . When the printer housing 10 is lifted away from the print media 22 , rotation W ceases, whereupon resilience of the capper arm 13 pushes the peg 20 back to the position depicted at FIG. 5 and at the same time returns the elastomeric pad 16 to seal the print chip 12 as shown in FIG. 5 .
[0086] In a fourth embodiment of the capping device shown in FIGS. 8 and 9 , there is provided an internally driven camshaft 24 including an eccentric cam 23 . Camshaft 24 might be selectively rotated by means of an electric motor for example. In this embodiment, the capper arm 13 is mounted to a pivot 14 and is biased by an integral spring 25 against the eccentric cam 23 . That is, the integral spring 25 biases the leg portion 28 of the capper arm 13 to the position depicted in FIG. 8 whereat the elastomeric pad 16 seals over chip 12 . When the camshaft 24 is rotated such that the eccentric cam rotates into the position depicted in FIG. 9 , the capper arm 13 deforms integral spring 25 while the elastomeric pad 16 moves away from the print chip 12 .
[0087] In FIGS. 10 and 11 of the accompanying drawings, there is depicted a fifth embodiment of the capping device wherein the capper arm 13 is activated by an internal solenoid 26 . In this embodiment, the capper arm 13 slides linearly between the positions depicted in FIGS. 10 and 11 . The capper arm 13 includes an integral spring 25 that bears against solenoid 26 . As an alternative, the spring 25 could bear against some other fixed internal structure of the printer housing 10 . Attached to the capper arm 13 is a metallic plate 27 to be attracted to the solenoid 26 by magnetic interaction therewith. Application of electric current to the solenoid 26 creates a magnetic field drawing the metal plate 27 thereto. This in turn draws the capper 13 to the uncapped position where the elastomeric pad 16 has moved away from the print chip 12 to enable printing to commence.
[0088] When the solenoid is no longer receiving electric current, its magnetic field diminishes or ceases enabling the spring 28 to return the capper arm 13 to the capped position depicted in FIG. 10 .
[0089] It should be appreciated that modifications and alterations obvious to those skilled in the art are not to be considered as beyond the scope of the present invention. For example, the elastomeric pad need not be affixed to the capper arm itself. Instead, it might be attached to the printhead 11 so as to surround the print chip 12 and come into sealing contact with a smooth surface of leg 28 of capper arm 13 . | An ink jet printer that includes a printhead configured to eject ink. The printhead is housed in a housing. A capping device is pivotally fastened with respect to the housing to be pivotal into and out of capping engagement with the printhead. The mechanism includes an arm pivotally mounted with respect to the housing and a capping leg extending transversely from the arm to cap the printhead. | 1 |
FIELD OF THE INVENTION
[0001] The present invention relates to a method and system for locating a mobile terminal in a cellular network based on a request received from an overlay system, such as a IP (Internet Protocol) Multimedia Subsystem (IMS).
BACKGROUND OF THE INVENTION
[0002] In general, overlay systems may be provided in cellular or fixed networks for enabling network operators to offer specific services based on and built upon applications, services and protocols not supported in their networks. The intention is that such services will be developed by the network operators and other third party suppliers using the mechanisms provided by external networks, such as the Internet or other external network systems or subsystems.
[0003] Recently, an IP Multimedia core network Subsystem (IMS) has been developed which comprises all core network elements for provision of multimedia services. This includes a collection of signalling and bearer related network elements as defined e.g. in the Third Generation Partnership Project (3GPP) specification TS 23.002. IP Multimedia services are based on an IETF (Internet Engineering Task Force) defined session control capability which, along with multimedia bearers, utilizes the PS (Packet Switched) domain of the cellular network. In order to achieve access independence and to maintain a smooth operation with wireless terminals across the Internet, the IMS attempts to be conformant to IETF “Internet Standards”. Therefore, the interfaces specified conform as far as possible to these standards for the case where an IETF protocol has been selected, e.g. SIP (Session Initiation Protocol). The IMS enables the convergence of, and access to, voice, video, messaging, data and to web-based technologies for the wireless user, and combines the growth of the Internet with the growth In mobile communications.
[0004] As already mentioned, the IMS utilizes the PS domain to transport multimedia signalling and bearer traffic. The PS domain maintains the service while the mobile terminal moves and hides these moves from the IMS. The IMS is independent of the CS (Circuit Switch) domain although some network elements may be common with the CS domain. This means that it is not necessary to deploy a CS domain in order to support an IMS based network. A User Equipment (UE) (or mobile station (MS)) consists of a mobile equipment (ME with a valid USIM (Universal Mobile Telecommunications System Subscriber Identity Module) (or SIM (Subscriber Identity Module)) attached. In the following, the abbreviation “UE” refers both to MS and user equipment, even those used for emergency calls, which do not have a valid SIM or USIM.
[0005] A UE accessing an IMS service requires an IP address which can be logically part of the visited network GPRS IP addressing domain. There are various identities which may be associated with a user of IP multimedia services. Every IMS subscriber has one or more public user identities. The public user identity is used by any user for requesting communications to other users. For example, this might be included on a business card. Both telecom numbering and Internet naming schemes can be used to address users depending on the public user identities allocated to the users. The public user identity may take the form of a SIP URL (Uniform Resource Locator) as defined in RFC 2543 and RFC 2396, or an E.164 number. At least one public user identity may be used to identify the user's information within a subscriber database, e.g. the Home Subscriber Server (HSS), e.g. during mobile terminated set-up.
[0006] A location service (LCS) feature in UMTS and GSM (Global System for Mobile Communications) provides a mechanism to support mobile location services for operators, subscribers and third party service providers. Location services may be considered as a network provided enabling technology consisting of standardized service capabilities which enable the provision of location applications. The applications may be service provider specific. In general, LCS is a service concept in a system standardization. LCS specifies all necessary network elements and entities, their functionalities, interfaces as well as communication messages to implement the positioning functionality in a cellular network. Positioning is a functionality which detects a geographical location of e.g. a mobile terminal. Principles and/or algorithms on which the estimation of the geographical location is based may be e.g. AOA, TOA or TDOA. For example, the Global Positioning System (GPS) is based on TOA while OTDOA and E-TD (on GSM) are based on TDOA.
[0007] The positioning of the UE is a service provided by the access network. In particular, all access networks (e.g. UMTS Terrestrial Radio Access Network (UTRAN), GSM/EDGE (Enhanced Datarate for GSM Evolution) Radio Access Network (GERAN), which facilitate determination of the locations of UEs, shall be able to exchange location information with a core network as defined in the 3GPP specification TS23.271, when connected to a core network.
[0008] By making use of the radio signals, the capability to determine the (geographic) location of the UE can be provided. The location information may be requested by and reported to a client (application) associated UE or by a client within or attached to the core network. The location information may also be utilized internally in a system, for example, for location assisted handover or to support other features, such as home location billing. The position information may be reported in standard, e.g. geographical coordinates, together with the time-of-day and the estimated errors (uncertainty) of the location of the UE according to the 3GPP specification TS 23.032. There are many different possible uses for the location information. As already mentioned, the positioning feature may be used internally by the GSM/UMTS network (or attached networks), by value-added network services, by the UE itself or through the network and by the third parties' services. The positioning feature may also be used by an emergency service. Although LCS has been defined for the CS and PS domains of cellular networks, it has not yet been defined for the IMS domain. Currently, the LCS service does not support IMS LCS clients to be addressed by IMS identities.
SUMMARY OF THE INVENTION
[0009] It is therefore an object of the present invention to provide a method and system for locating a mobile terminal addressed by an overlay identity used in an overlay system, e.g. an IMS identity used in the IMS.
[0010] This object is achieved by a method of locating a mobile terminal in a cellular network, said method comprising the steps of:
[0011] receiving a location service request including an overlay identity of an overlay system;
[0012] accessing a database storing a first routing information of said mobile terminal based on said overlay identity;
[0013] Using said first routing information to access a subscriber database in order to derive a second routing information and a cellular identity of said mobile terminal; and
[0014] initiating a location service of said cellular network based on said derived second routing information and cellular identity.
[0015] Additionally, the above object is achieved by a system for locating a mobile terminal in a cellular network, said system comprising:
[0016] a gateway node for receiving a location service request including an overlay identity of said mobile terminal in an overlay system;
[0017] a database storing a first routing information of said mobile terminal;
[0018] wherein said gateway node is arranged to access said database based on said overlay identity, to use said first routing information for an access to a subscriber database in order to derive a second routing information and a cellular identity, and to initiate a location service of said cellular network based on said derived second routing information and cellular identity.
[0019] Furthermore, the above object is achieved by a gateway node for initiating a location service for locating a mobile terminal in a cellular network, said gateway node being arranged to read a first routing information from a database based on a received overlay identity of said mobile terminal in an overlay system, to use said first routing information for an access to a subscriber database in order to derive a second routing information and a cellular identity, and to perform said initiation based on said derived second routing information and cellular identity.
[0020] Accordingly, an address mapping functionality is provided for enabling a location service for clients in overlay systems to be addressed by overlay identities, using existing LCS functionalities.
[0021] Preferably, other identities of said mobile terminal may be derived from said subscriber data base in said subscriber data base access step. In particular, the other identities may be stored in a network element having a mobile location function. Thereby, signaling requirements for deriving the other identities of the mobile terminal in future location service requests can be reduced significantly. The overlay identity may be an IMS identity, in particular a SIP URL.
[0022] Furthermore, the first routing information may be a country code, e.g. a Mobile Country Code (MCC), and a network code, e.g. Mobile Network Code (MNC), of said mobile terminal.
[0023] The subscriber database access step may preferably be performed by using a MAP query, such as a MAP-SEND-ROUTING-INFO-FOR-LCS service function.
[0024] The cellular identity may be an MSISDN or IMSI, and the second routing information may be an address of a network element having a switching function in the cellular network.
[0025] The gateway node may be a Gateway Mobile Location Center (GMLC). The database may be comprised in the gateway node or may be a separate external entity.
[0026] The subscriber database may be a Home Location Register (HLR) of the cellular network. In this case, the HLR may be arranged to derive the second routing information and the cellular identity by performing a query to a Home Subscriber Server. Furthermore, the HLR may be arranged to derive other identities of the terminal device.
[0027] Preferably, the database may be arranged to provide a mapping function between the first routing function and the overlay identity of the terminal device.
[0028] Furthermore, the gateway node may be arranged to store the second routing information and/or the cellular identity, for further use.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] In the following, the present invention will be described in greater detail based on a preferred embodiment with reference to the accompanying drawings, in which:
[0030] FIG. 1 shows a network architecture for implementing a location service function according to the preferred embodiment of the present invention;
[0031] FIG. 2 shows a signaling diagram indicating exchanged signaling messages and procedures in a location service function according to the preferred embodiment of the present invention; and
[0032] FIG. 3 shows a table indicating parameters of a MAP query function used in the preferred embodiment;
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0033] The preferred embodiment will now be described based on an LCS architecture in a UMTS network as shown in FIG. 1 . According to FIG. 1 , a reference point, called Le Interface, is shown between an LCS server (here: GMLC 50 ) and an LCS client 80 which, in the present embodiment, is an IMS server or application. The Le reference point is described in the 3GPP Specification TS 22.071. However, there may be more than a single LCS network interface to several different LCS clients or other networks. These networks may both differ in ownership as well as in communications protocol. The network operator may define and negotiate interconnection with each external LCS client or other network. In general, an interface differs from a reference point in that an interface is defined where specific LCS information is exchanged and needs to be fully recognized.
[0034] Furthermore, an interface called Lg is arranged to connect two independent LCS networks, e.g. different PLMNs (Public Land Mobile Networks) for message exchange. The LCS functional entities are grouped into an LCS client functional group and an LCS server functional group. The LCS server functional group consists of functions in the UMTS PLMN supporting LCS, e.g. a client handling component, a system handling component, a subscriber handling component, and a positioning component. The LCS client 80 contains an LCS component with one or more clients, which by using location information can provide location based services. In particular, the LOS client 80 is a logical functional entity that requests from the LCS server in the PLMN location information for one or more than one target UE, i.e. a UE 10 shown in FIG. 1 , within a specified set of parameters such as Quality of Service of QoS.
[0035] In the present architecture shown in FIG. 1 , the LCS client 80 resides in an external entity belonging to an overlay system, i.e. the IMS. Via a location service request, the LCS client 80 communicates with the LCS server, i.e. GMLC 50 , to request for the location information of the UE 10 . Attributes identified by the location service request may be target UE, LCS identity, state, event, requested QoS information, local coordinate reference system, and/or geographical area. A location service response is sent to the LCS client 80 as the result of the location service request issued by the LCS server. Attributes identified for the location service response may be the location indication of the UE 10 in geographical coordinates, the location of the UE 10 as an ellipsoid with axes and direction of all axes, an estimated achieved QoS, and/or an indication when UE 10 enters or leaves the geographical area.
[0036] FIG. 1 illustrates generally the relation of the LCS client 80 and servers in the core network with a GERAN 20 and a UTRAN 30 . The LCS entities within the access networks communicate with the core network consisting of a 2G-MSC 22 of the CS domain, a 2G-SGSN 24 of the PS domain, a 3G-SGSN 32 of the PS domain, and an MSC server 34 of the PS domain across A, Gb and lu interfaces. Communication among the access network LCS entities makes use of the messaging and signaling capabilities of the access network.
[0037] Furthermore, a subscriber database, i.e. a HLR/HSS 40 is provided for storing subscriber specific data of the UE 10 and other mobile terminals or equipments. It is noted that the HLR and HSS may be arranged at different locations, while the HLR part may include both 2G-HLR and 3G-HLR functionalities. In this respect it is noted, that the terms “2G” and “3G” denote second and third generation mobile communication functionalities, respectively.
[0038] With this configuration both the network and the UE 10 are able to measure the timing of signals and compute a location estimate of the UE 10 . Depending on the applied positioning method it is possible to utilize the corresponding configuration containing all needed entities. For instance, if network-based positioning is applied, the entities that are involved in measuring the mobile's signal and calculating its location estimate are allocated to the network elements of the access stratum. On the other hand, in case mobile-based or network-assisted methods are used entities should be allocated to the UE 10 .
[0039] The GMLC 50 contains functionality required to support LCS. In one PLMN, there may be more than one GMLC. The GMLC 50 is the first node the external LCS client 80 accesses in a GSM PLMN (i.e. the Le reference point is supported by the GMLC 50 ). The GMLC 50 may request routing information from the HLR/HSS 40 via a Lh interface. After performing registration authorization, it sends positioning requests to either the 2G-MSC 22 , SGSNs 24 , 32 or MSC server 34 and receives final location estimates from the corresponding entity via the Lg interface. The UE 10 may be involved in various positioning procedures. Specific UE involvement is specified in each of the positioning procedures mentioned in the 3 GPP specification TS 25305 for the UTRAN 30 and TS 43.059 for the GERAN 20 . The 2G-MSC 22 contains a functionality responsible for UE subscription authorization and managing call related and non-call related positioning requests of LCS. The 2G-MSC 22 is accessible to the GMLC 50 via the Lg interface. The LCS functions of the 2G-MSC 22 are related to charging and billing LCS coordination, location request authorization and operation of the LCS services. If connected to the 2G-SGSN 24 through a Gs interface, it checks whether the UE 10 is GPRS attached to decide whether to page the UE 10 on the A or Gs interface.
[0040] The MSC server 34 handles the same functionality as the 2G-MSC 22 including charging and billing, LCS coordination, location requests, authorization and operation of the LCS services. The MSC server 34 is accessible to the GMLC 50 via the Lg interface. Furthermore, the 2G- and 3G-SGSNs 24 , 32 contain a functionality responsible for UE subscription authorization and managing positioning requests of LCS. The SGSNs 24 , 32 are accessible to the GMLC via the Lg interface. The LCS functions of the SGSNs 24 , 32 are related to charging and billing, LCs coordination, location request, authorization and operation of the LCS services. The SGSNs 24 , 32 forward the CS paging request received from the Gs interface to a base station subsystem or radio network controller of the respective access network.
[0041] The HLR/HSS 40 is accessible from the GMLC 50 via a Lh interface. For a roaming UE, the HLR/HSS 40 may be in a different PLMN.
[0042] Furthermore, a gsmSCF (GSM service control function) provides an Lc interface to support access between the LCS and a network functionality CAMEL (Customized Applications for Mobile Network Enhanced Logic) providing the mechanisms of Intelligent Network to a mobile user. The procedures and signaling associated with it are defined in the 3GPP specification TS 23.078 and TS 29.002, respectively.
[0043] An important point is the possibility to address and indicate the target UE 10 using a cellular identity, e.g. the MSISDN (Mobile Station Integrated Services Data Network) or IMSI (International Mobile Subscriber Identity), or the like. However, in the present case, the external LCS client 80 belongs to the IMS and thus uses an IMS identity in the location service request supplied to the GLMC 50 . Therefore, a mapping function is provided for mapping the IMS identity of the UE 10 with a routing information required for accessing the HLR/HSS 40 allocated to the target UE 10 . Thereby, an IP addressing of the target UE 10 can be performed without requiring an active PDP context established between the target UE 10 and the external LCS client 80 .
[0044] The Lh interface between the GMLC 50 and the HLR/HSS 40 may be based on a Mobile Application Part (MAP) protocol. This interface Lh is used by the GMLC 50 to request a routing information to the serving MSC or SGSN of the particular target UE 10 whose location has been requested. The Lg interface is used by the GMLC 50 to convey the location request to the respective MSC or SGSN function currently serving the target UE 10 . Furthermore, the Lg interface is used by the respective MSC or SGSN function to return location results to the GMLC 50 .
[0045] For the LCS service, a MAP-SEND-ROUTING-INFO-FOR-LCS service is used between the GMLC 50 and the HLR/HSS 40 to retrieve the routing information needed for routing a location service request to the serving MSC or SGSN function. In case the GMLC 50 receives a location service request from the external LCS client 80 , which contains an IMS identity the GMLC 50 accesses the database 60 which may be arranged in the GMLC 50 or as a separate external entity to derive the routing information to the HLR/HSS 40 . The IMS identity may be a public identity, such as a SIP URL, which is mapped by the HRL/HSS 40 to a cellular routing information, e.g. an MCC and MNC of the home network of the target of the UE 10 . Using this cellular routing information the GMLC 50 accesses the HLR/HSS 40 by a MAP query, e.g. a MAP-SEND-ROUTING-INFO-FOR-LCS message comprising the IMS identity, e.g. SIP URL. The HRL part of the HRL/HSS 40 may access the HSS part based on an interworking function to obtain the IMSI or any other cellular identity of the target UE 10 from the HSS part based on a corresponding mapping function. Using this cellular identity, the GMLC 50 initiates a location service function within the cellular network via the Lg interface. Thereby, an IMS LCS service functionality can be provided in the UMTS/GSM network architecture.
[0046] FIG. 2 shows a signaling diagram indicating basic signaling messages and procedures required for the location service function. In particular, the external LCS client 80 requests the current location of the target UE 10 from the GMLC 50 by using a LSC service request comprising the IMS ID of the target UE 10 (step 1 ). In response thereto, GMLC 50 accesses the database 60 and transfers the IMS ID to the database 60 . Based on the mapping function provided at the database 60 the corresponding cellular routing information MCC/MNC is returned to the GMLC 50 . Then, the GMLC 50 uses this routing function to route a MAP query comprising the MS ID to the concerned HLR/HSS 40 identified by the MCC/MNC (step 2 ). In response thereto, the HLR/HSS 40 returns the cellular identity (e.g. MSI) of the target UE 10 and a routing information (address of the serving network element) required for routing the LSC service request in the cellular network (step 3 ). Now that the GMLC 50 knows both, the IMSI and location of the serving network element, the location service procedure can be invoked in the cellular network (step 4 ). Finally, the GMLC 50 sends the location service response received from the cellular network to the external LCS client 80 (step 5 ).
[0047] To implement the mapping function between the IMS identity and the cellular identity in the HLR/HSS 40 , a new parameter has to be introduced into the MAP query message, e.g. the MAP-SEND-ROUTING-INFO-FOR-LCS message. FIG. 3 indicates this new parameter, e.g. IMS identity as a conditional parameter for location service requests including an IMS identity. Thereby, the HLR/HSS 40 is in a position to provide the mapping function so as to retrieve the cellular identity of the target UE 10 . Thus, the MAP-SEND-ROUTING-INFO-FOR-LCS service is enhanced so that it can carry whatever public IMS identity is available to the GMLC 50 . The GMLC 50 is arranged to put the IMS identity to the MAP-SEND-ROUTING-INFO-FOR-LCS service request message instead of the conventionally used cellular identity, e. g. IMSI or MSISDN. From the point of view of the HLR/HSS 40 the new parameter is optional, i.e. if provided, a query to the HSS part is needed to map the public IMS identity to the cellular identity. The HLR/HSS 40 then returns the retrieved cellular identity to the GMLC 50 in a MAP-SEND-ROUTING-INFO-FOR-LCS service reply and the conventional CS or PS LCS methods can be used to locate the UE 10 . The GMLC 50 may store the mapping between the IMS identity and the cellular identity in its internal database or memory for further queries.
[0048] Furthermore, the preferred embodiment may be enhanced by returning all public IMS identities known in the HSS part of the HLR/HSS 40 to the GML 50 , so that any further location requests with other identities would not require a HLR query at all as long as the location result in the GMLC 50 is still actual.
[0049] It is to be noted that the present invention is not restricted to the provision of a location service in a IMS environment, but can be used for providing a location service in any overlay system having an own overlay identity allocated to the target mobile terminal. Thus, the preferred embodiment may vary within the scope of the attached claims. | The present invention relates to a method and system for locating a mobile terminal addressed in a location service request by an overlay identity. A database ( 60 ) is accessed to obtain a first routing information of the mobile terminal based on the overlay identity, and the first routing information is then used to access a sub-scriber database ( 40 ) in order to derive a second routing information and a cellular identity of the mobile terminal ( 10 ), based on which a location service of the cellular network is initiated. Thereby, a LCS clients of the overlay system (e.g. IMS) can be supported in current LCS services to enhance their functionality. | 7 |
FIELD OF THE INVENTION
[0001] The present invention relates to surfaces simulating natural grass and, more specifically, to tufted structure such as an artificial turf, imitating the volume effect and density of natural grass and manufacturing such turf
BACKGROUND OF THE INVENTION
[0002] Artificial turf, also often referred to as synthetic grass, is a surface of synthetic fibers made to look like natural grass. It is most often used in sports applications. However, it is now being used on residential lawns and landscaping as well. Artificial turf stands up to heavy use and requires no irrigation or trimming. Domed, covered, and partially covered stadiums may require artificial turf because of the difficulty of getting grass enough sunlight to stay healthy. But, artificial turfs currently available still fail to provide the excellent shock absorbing properties of natural grass surfaces and also fall short in mimicking the volume effect of natural grass.
[0003] Today's generation artificial turfs are typically made from UV-enhanced polypropylene fiber or polyethylene fiber that is tufted into a woven synthetic primary backing that receives a secondary backing in form of a coating or laminate on the opposite side of the face fibers to give the turf dimensional stability and to aid fiber binding.
[0004] When installed, the turf's face (i.e., the grass “blades”) is generally given a layer of sand to augment water drainage and/or a layer of cryogenic rubber granules to help keeping the tufts more vertically oriented and to provide shock-absorbency.
[0005] The infill typically provides ballast and structure for the artificial turf, helping the fibers to stand and to provide a “cushion” effect when stepping over the turf. This protects the roots of the tuft fibers.
[0006] Currently, non-infill artificial turf refers to those artificial turf models with short pile height, narrow gauge (distance between rows), and high stitch rate. Artificial turfs that are used without such infill are typically made from shorter, denser polyethylene fibers that include even shorter crimped fibers to keep the tufts resembling grass blades upright. Some non-infill systems provide an underlay under the turf to provide cushioning.
[0007] Due to an ever increasing number of residential and commercial applications of artificial turf, artificial turf with improved properties that more and more resemble natural grass is sought after, as illustrated in the following examples.
[0008] GB 1,154,842 discloses raised tufted, bonded fibrous structures. A fibrous web of desired weight and structure was placed on top of another such web and the assembled fibrous structure then needle punched in a conventional single bed needle loom. On passage through the needle loom, fibres from one fibrous web are carried by the needles through the other fibrous web as the foundation layer and the needle penetration is controlled so as to ensure that the aligned fibres pass through the foundation layer and project beyond its surface as fibre tufts.
[0009] WO 2001/37657 A1 discloses a vertically draining, rubber filled synthetic turf. The vertically draining synthetic turf comprises a porous geotextile membrane positioned between an open graded aggregate layer and a sand layer. The synthetic turf also includes a pile fabric comprising a plurality of pile elements tufted to a woven or non-woven backing above the open graded aggregate layer. An infill layer consisting of resilient particles, preferably a mixture of high and low density rubber, is interspersed among the pile elements of the pile fabric. The backing layer may be solely a non-woven, in a single layer or in multiple layers. A suitable non-woven, dimensionally stable material is a polyester/nylon blend, spun-bound, non-woven material.
[0010] WO 2012/125513 A1 discloses a synthetic ground cover system for erosion control to be placed atop the ground, which includes a synthetic grass comprising a composite of one or more geo-textiles tufted with synthetic yarns. The synthetic ground cover also includes a sand/soil infill ballast applied to the synthetic grass and a binding agent applied to the sand/soil infill to stabilize the sand/soil infill against high velocity water shear forces. The system includes a synthetic turf which includes a backing and synthetic turf blades secured to the backing. The synthetic grass blades are tufted into the substrate or backing comprising a synthetic woven or non-woven fabric. The backing can be a single ply backing or can be a multi-ply backing, as desired. A filter can be secured to the substrate to reinforce the substrate and better secure the synthetic grass blades. Preferably, the at least one filter fabric may also comprise non-woven synthetic fabric.
[0011] As more artificial turf and less natural grass is used to cover the ground for an increasing number of applications, it is increasingly important to provide artificial turf that is eco-friendly.
SUMMARY OF THE INVENTION
[0012] From the foregoing, it can be seen that there is a need for a tufted structure that resembles more closely natural grass.
[0013] The present invention seeks to provide a tufted structure, such as an artificial turf for landscape and sports applications, that imitates more closely the root zone, the volume effect, and density of natural grass and that has an improved wear and drainage property.
[0014] It is an advantage of embodiments of the present invention to provide the artificial turf with a bounded layer of fibers, in particular a mechanically bounded layer of fibers, functioning as the root zone of natural grass that assists the pile yarn of the tufts to stand and that protects the bending points of the tufts such that the application of an infill can be eliminated. The bounded layer of fibers allows moving of the fiber so that compaction of the surface, thus hardening of the surface will be extensively be reduced.
[0015] It is another advantage of embodiments of the present invention that the tufted structure can be made from materials that are entirely recyclable thereby reducing the amount of waste that presently has to be disposed of in landfills.
[0016] It is still another advantage of embodiments of the present invention to enable surface water to drain easily in all directions to the ground underneath the tufted structure when installed as an artificial turf
[0017] It is yet another advantage of embodiments of the present invention to provide artificial turf with a bounded layer of fibers for equalizing for uneven/rocky soils.
[0018] It is yet another advantage of embodiments of the present invention to provide a tufted structure with a bounded layer of fibers that has shock absorbing properties and, thus, contributes to a more natural feeling of the artificial turf
[0019] According to an aspect of the present invention, a tufted structure for use in landscape and sports applications comprises a bounded layer of fibers made of one or more natural and/or synthetic fibers. Pile yarn is inserted through the bounded layer of fibers, the pile yarn being anchored to the bounded layer of fibers. The bounded layer of fibers has a density that decreases from the bottom to the top of the bounded layer of fibers.
[0020] The tufted structure may be an artificial turf. By providing a bounded layer of fibers, such as a mechanically bounded layer of fibers, which may be formed as a non-woven matting, surface water can drain easily to the soil underneath the artificial turf once installed. As a result, the artificial turf in accordance with advantageous embodiments of the present invention dries quickly provided drainage of the subsoil. By using a mixture of natural and, therefore, moisture absorbent fibers and synthetic fibers, the water holding capacity of the artificial turf can be improved compared to known prior art products.
[0021] According to preferred embodiments of the present invention, decrease in density occurs at a constant rate. As a result, the layer provides structural support for the tufts and shock-absorbance to contribute to a more natural feeling of the artificial turf.
[0022] According to preferred embodiments of the present invention, the bounded layer of fibers includes a lower layer and a upper layer, the lower layer being positioned at the bottom of the bounded layer of fibers and the upper layer being positioned on top of the lower layer, and the upper layer having a higher fiber coarseness than the lower layer.
[0023] The terms “upper” and “top”, on the one hand, and “lower” and “bottom”, on the other hand, are used herein to designate sides or portions of the artificial turf with reference to their relative positioning when the turf is deployed for normal use on a ground surface. Thus, “upper” and “top” refer to portions at or near the side from which free ends of the tufts stick out; and “lower” and “bottom” refer to portions at or near the opposite side.
[0024] This embodiment also provides structural support for the tufts and shock-absorbance to contribute to a natural feeling of the artificial turf, while allowing an efficient manufacturing process starting from two homogeneous non-woven mats having different fiber coarseness.
[0025] According to preferred embodiments of the present invention, the lower layer provides structural support for the pile yarn.
[0026] According to preferred embodiments of the present invention, the upper layer acts as a shock-absorbing layer and contributes to a natural feeling of the artificial turf.
[0027] According to preferred embodiments of the present invention, the lower layer is formed by fibers that are more flexible and form a denser structure than fibers forming the upper layer, the fibers of the lower layer having a smaller linear mass density than fibers forming the upper layer.
[0028] According to preferred embodiments of the present invention, the fibers of the lower layer have a linear mass density in the range of about 3,3 dtex to about 110 dtex.
[0029] According to preferred embodiments of the present invention, wherein the fibers of the upper layer have a linear mass density in the range of about 11 dtex to about 600 dtex.
[0030] According to preferred embodiments of the present invention, the upper layer is thicker and has a higher fiber coarseness than the lower layer.
[0031] According to preferred embodiments of the present invention, fill yarn is created on the upper surface of the upper layer through velour needle-punching, the fill yarn giving the upper surface of the upper layer a velour-like appearance, thereby imitating the root zone of natural grass, providing cushioning, and assisting the pile yarn of the tufts to stand. By velour-needle punching the upper surface of the upper layer, the surface is given a fluffy structure that provides cushioning. Since the fill yarn assists the pile yarn to stand, no infill, as often used in the known prior art is needed with the artificial turf in accordance with advantageous embodiments of the present invention.
[0032] According to preferred embodiments of the present invention, the bounded layer of fibers is manufactured as a single fabric or as two separate fabrics that are joined together.
[0033] According to preferred embodiments of the present invention, the bounded layer of fibers is formed by needle-punching.
[0034] According to preferred embodiments of the present invention, the bounded layer of fibers consists of up to eight different types of fibers.
[0035] According to preferred embodiments of the present invention, the bounded layer of fibers, the pile yarn, and a backing anchoring the pile yarn to the bounded layer of fibers are made of eco-friendly materials that are 100% recyclable by being mechanically deconstructable. It is furthermore advantageous to choose a homogenous polymer composition for all elements of the inventive artificial turf to support the recyclability.
[0036] Independently of the considerations explained above, a similar technical effect can be obtained by a tufted structure for use in landscape and sports applications, comprising a bounded layer of fibers made of one or more natural and/or synthetic fibers, and pile yarn inserted through the bounded layer of fibers, the pile yarn being anchored to the bounded layer of fibers, wherein the bounded layer of fibers has a thickness of at least 3 mm. The thickness referred to herein may be measured in accordance with European standard EN1765.
[0037] According to an aspect of the present invention, a method for manufacturing a tufted structure, such as an artificial turf for use in landscape and sports applications, comprises the steps of:
forming by needle-punching a bounded layer of fibers having a density that decreases from the bottom to the top of the bounded layer of fibers; creating fill yarn extending the upper surface of the bounded layer of fibers through velour needle-punching, thereby giving the upper surface of the bounded layer of fibers a velour-like appearance; inserting pile yarn through the bounded layer of fibers; and anchoring the pile yarn at the backside of the bounded layer of fibers.
[0039] According to an aspect of the present invention, a method for manufacturing a tufted structure, such as an artificial turf for use in landscape and sports applications, comprises the steps of: forming by needle-punching a lower layer from a plurality of natural and/or synthetic fibers; forming by needle-punching an upper layer from a plurality of natural and/or synthetic fibers that have a higher linear mass density than the fibers of the lower layer, the upper layer having a less dense structure than the lower layer; placing the upper layer on top of the lower layer to form a bounded layer of fibers; creating fill yarn on the upper surface of the upper layer through velour needle-punching thereby giving the upper surface of the upper layer a velour-like appearance; inserting pile yarn through the bounded layer of fibers; and anchoring the pile yarn at the backside of the bounded layer of fibers.
BRIEF DESCRIPTION OF THE DRAWINGS
[0040] The above and other characteristics, features, and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention. This description is given for the sake of example only, without limiting the scope of the invention. The reference figures quoted below refer to the attached drawings.
[0041] FIG. 1 is a schematic cross-sectional view of the artificial turf in accordance with a first preferred embodiment of the present invention; and
[0042] FIG. 2 is a schematic cross-sectional view of the artificial turf in accordance with a second preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0043] The present invention will be described with respect to particular embodiments and with reference to certain drawings but the invention is not limited thereto but only by the claims. Any reference signs in the claims shall not be construed as limiting the scope. The drawings described are only schematic and are non-limiting. In the drawings, the size of some of the elements may be exaggerated and not drawn on scale for illustrative purposes.
[0044] Where the term “comprising” is used in the present description and claims, it does not exclude other elements or steps. Where an indefinite or definite article is used when referring to a singular noun e.g. “a” or “an”, “the”, this includes a plural of that noun unless something else is specifically stated.
[0045] Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment, but may. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments.
[0046] Similarly it should be appreciated that in the description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this invention.
[0047] Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form different embodiments, as would be understood by those in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination.
[0048] In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the invention may be practiced without these specific details. In other instances, well-known methods, structures, and techniques have not been shown in detail in order not to obscure an understanding of this description.
[0049] The following terms or definitions are provided solely to aid in the understanding of the invention.
[0050] The term “backside” is used herein to denote the side of the bounded layer of fibers which faces away from the side from which free edges of the tufts stick out.
[0051] As employed herein, the term “fiber coarseness” is defined as weight per fiber length and is normally expressed in units of mg/m or g/m. The fiber coarseness depends on fiber diameter, cell wall thickness, cell wall density, and fiber cross section. A high coarseness value indicates a thick fiber wall, giving stiff fibers unable to collapse. Thin walled fibers with low coarseness value give flexible fibers and a denser structure. The coarser the fibers, the stronger they will be.
[0052] As employed herein, the term “tex” refers to a unit of measure for the linear mass density of fibers and is defined as the mass in grams per 1000 meters. The most commonly used unit is the decitex, abbreviated dtex, which is the mass in grams per 10,000 meters. When measuring objects that consist of multiple fibers the term “filament tex” is sometimes used, referring to the mass in grams per 1000 meters of a single filament.
[0053] As employed herein, the term “tufting” refers to a type of textile process in which a thread is inserted on a carrier base. Tufted carpets are manufactured by insertion of tufts (a short cluster of elongates strands of yarn attached at the base) through a backing fabric, creating a pile surface of cut and/or loop ends.
[0054] As employed herein, the term “filament” refers to a single continuous strand of natural or synthetic fiber.
[0055] As employed herein, the term “yarn” refers to a continuous strand of twisted or untwisted threads of natural or synthetic material.
[0056] As employed herein, the term “pile” refers to the visible surface (wearing surface) of carpet consisting of upright ends of yarn or yarn tufts in loop and/or cut configuration. Sometimes it is called “face” or “nap”.
[0057] As employed herein, the term “backing” refers to a substrate applied to the back of the carpet to increase dimensional stability and enhances the anchoring of the pile yarn.
[0058] As employed herein, the term “non-woven” refers to engineered fabric (sheet or web structure) bonded together by entangling fibers mechanically, thermally, or chemically.
[0059] As employed herein, the term “needle-punch” refers to a mechanical process involving thousands of needles that orient and interlock fibers to create nonwoven fabric.
[0060] Referring to FIG. 1 , the schematic cross-section of an artificial turf 10 is illustrated in accordance with preferred embodiments of the present invention. The artificial turf 10 includes a bounded layer of fibers 20 , preferably mechanically bounded, a backing 30 , and a plurality of tufts 40 .
[0061] The bounded layer of fibers 20 may be formed as a non-woven matting made of one or more natural and/or synthetic fibers or yarns. The bounded layer of fibers 20 serves as a carrier for the tufts 40 .
[0062] As illustrated in FIG. 1 , the bounded layer of fibers 20 can be a single layer containing a mixture of fibers. According to preferred embodiments of the present invention, the coarseness of the fibers forming the bounded layer of fibers 20 may increase from the bottom to the top of the layer 20 . For example, the coarseness may gradually increase at a constant rate.
[0063] Alternatively, as illustrated in FIG. 2 , the bounded layer of fibers 20 can include visually two or more layers, such as, a structural layer 21 and a volume simulating layer 22 . The structural layer 21 is positioned at the bottom of the bounded layer of fibers 20 facing away from the pile yarn 41 . The volume simulating layer 22 is positioned on top of the structural layer 21 facing the pile yarn 41 . In case of multiple layers of fibers, the bounded layer of fibers is divided into multiple functionalities, such as, for example, structural enhancements (layer 21 ) and volume simulating (layer 22 ).
[0064] The bounded layer of fibers 20 can be manufactured as a single fabric or as two separate fabrics that are joined together. In accordance with preferred embodiment of the present invention, the bounded layer of fibers 20 is formed by needle-punching. During this mechanical bonding method, fibers are transported with felting needles and interlocked in the non-woven structure. This procedure increases the friction between the fibers, which reinforces the non-woven fabric. To differentiate the structure of the non-woven fabric, the web can be further structured using special machines equipped with structuring fork or crown needles. The surface can be structured as a velour or rib, or with geometrical or linear patterns. Needle-punching is an ecologically friendly technology, as it permits the use of recycled material including that from polyethylene terephthalate bottles and regenerated fibers from apparel, as well as natural fibers. It may be possible to use other technologies to form non-woven fabrics to obtain the bounded layer of fibers 20 .
[0065] The bounded layer of fibers 20 may consist of up to eight different types of fibers. Each of the fibers can have a different color, if desired. The types of fibers can include moisture absorbent fibers, such as coco, cotton, jute, wool, rayon or other natural or synthetic fibers. The types of fibers can further include synthetic fibers, such as polypropylene (PP), polyethylene (PE), polyamides (PA), and polyester (PES) or a combination thereof. The fibers can be treated, for example, with anti-algae, with herbicide, UV-stabilizer, or to be anti-static. The fibers can be melt fibers. The fibers can among others further include mineral based fibers, animal based fibers, or plant based fibers.
[0066] If the bounded layer of fibers 20 is formed as a single layer, as shown in FIG. 1 , a mixture of relatively thin walled fibers that are flexible and form a relatively dense structure and, thus, having a relatively low coarseness value and relatively thick walled fibers that are stiff and form a relatively sparse structure and, thus, having a relatively low coarseness value is used in combination. In an exemplary embodiment of the invention, the density of the bounded layer of fibers 20 can gradually decrease from the bottom to the top of the layer 20 . Accordingly, the coarseness of the fibers will gradually increase from the bottom to the top of the layer 20 . By designing the bounded layer of fibers 20 that way, structural support for the tufts 40 and protection for bending points 42 of the tufts 40 is provided as well as shock-absorbance to contribute to a more natural feeling of the artificial turf 10 .
[0067] If, according to preferred embodiments of the present invention, the bounded layer of fibers 20 is formed as a single layer, as shown in FIG. 2 , the structural layer 21 is formed by relatively thin walled fibers that are flexible and form a relatively dense structure. Accordingly, fibers with the relatively low linear mass density (dtex value) are selected for the structural layer 21 . The structural layer 21 is utilized for anchoring the tufts 40 . The structural layer 21 provides dimensional stability for the artificial turf 10 and protection for the bending points 42 of the tufts 40 . The fibers of the structural layer 21 have preferably a linear mass density in the range of about 3,3 dtex to about 110 dtex, and more preferably of about 11 dtex.
[0068] The volume simulating layer 22 is formed by fibers having a larger linear mass density than the fibers of the structural layer 21 . The fibers of the volume simulating layer 22 have preferably a linear mass density in the range of about 11 dtex to about 600 dtex, and more preferably of about 110 dtex. Consequently, the volume simulating layer 22 has also a higher fiber coarseness (weight per fiber length) than the structural layer 21 . A high coarseness value indicates a thick fiber wall, giving stiff fibers unable to collapse. Therefore, the volume simulating layer 22 of the bounded layer of fibers 20 is thicker and coarser than the structural layer 21 . Fibers with a higher dtex value are selected for the volume simulating layer 22 so that the bounded layer of fibers 20 can act as a shock-absorbing layer and contribute to a natural feeling of the artificial turf 10 .
[0069] In addition, the fibers of the bounded layer of fibers 20 can be given a velour effect by needling to mimic the root zone volume effect of natural grass. Due to a mechanical needling process, fiber is pushed out of the upper surface of the layer 20 . Velour needle-punched non-woven material can be produced by placing an non-woven material on a brush-like stitch base and needling of the non-woven material on this stitch base. Since with this method the fibers seized by the needles are needled into the bristles or lamellas of the needle stitch base, the non-woven material needled in this way is given a velour-like appearance where the fiber stands out above the surface.
[0070] By velour needle-punching the bounded layer of fibers 20 , fill yarn 23 is created. The fill yarn 23 is punched out of the non-woven fibrous matting of the bounded layer of fibers 20 creating a natural grass like root zone . The fill yarn 23 gives the upper surface of the bounded layer of fibers 20 (facing the pile yarn 41 ) a fluffy appearance and provide cushioning. The fill yarn 23 also assists the pile yarn 41 of the tufts 40 to stand. Thus, no infill, as often used with prior art artificial turf, is needed with the artificial turf 10 in accordance with preferred embodiments of the present invention.
[0071] Strands of pile yarn 41 form each tuft 40 . A tuft 40 is a short cluster of elongates strands of pile yarn 41 attached at the base, the bending point 42 . The tufts 40 are inserted through the bounded layer of fibers 20 . Tufting usually is accomplished by inserting reciprocating needles threaded with pile yarn 41 into the bounded layer of fibers 20 to form tufts 40 of yarn. Loopers or hooks, typically working in timed relationship with the needles, are located such that the loopers are positioned just above the needle eye when the needles are at an extreme point in their stroke through the bounded layer of fibers 20 . When the needles reach that point, pile yarn 41 is picked up from the needles by the loopers and held briefly. Loops or tufts 40 of yarn result from passage of the needles back through the bounded layer of fibers 20 . This process typically is repeated as the loops move away from the loopers due to advancement of the backing through the needling apparatus. Subsequent, the loops can be cut to form a cut pile, for example, by using a looper and knife combination in the tufting process to cut the loops.
[0072] The pile yarn 41 can consist of up to four different types of yarns. Each yarn can have a different color, if desired. The pile yarn 41 can be monofilament, tape or a combination thereof. The pile yarn 41 has preferably a linear mass density of about 400 dtex to about 3000 dtex and, more preferably of about 1600 dtex. The number of strands of pile yarn 41 in a tuft 40 is between 2 and 10, and preferably 6. The tuft gauge (distance between rows) is between ½″ and 1/16″ and typical ⅜″ or 3/16″ or ⅛″. The stitch rate of the tufting is between 8/10 cm and 30/10 cm and preferably 12/10 cm.
[0073] In accordance with preferred embodiments of the invention and as shown in FIG. 2 , the bounded layer of fibers 20 may have a height H 3 of about 3 mm to about 15 mm, and more preferably about 8 mm. The fill yarn 23 may extend from the upper surface of the bounded layer of fibers 20 for a height H 2 of about 1 mm to about 20 mm, and more preferably of about 10 mm. The pile yarns 41 may extend from the fill yarn 23 for about 1 mm to about 20 mm, and more preferably 10 mm (height H 1 ). The total height H 4 of the artificial turf 10 may be about 10 mm to about 60 mm, and more preferably about 28 mm.
[0074] The backing 30 is applied to the bounded layer of fibers 20 as a last finishing step to enhance the anchoring of the tufts to the bounded layer of fibers 20 . In accordance with preferred embodiments of the present invention the backing 30 can be a coated backing such as, for example, a polyethylene (PE) backing that is applied by means of powder or hot melt coating. The backing 30 can further be a calander backing or latex backing.
[0075] In the finishing operation, the backside or stitched surface of the bounded layer of fibers 20 is coated with an adhesive, such as a natural or synthetic rubber or resin latex or emulsion or a powder or hot melt adhesive, to enhance locking or anchoring of tufts 40 to the bounded layer of fibers 20 . Use of such further improves dimensional stability of the tufted turf 10 , resulting in more durable turf. Further stabilization can be provided in the finishing operation by laminating, for example, a thermoplastic film or a woven or nonwoven fabric made from polypropylene, polyethylene, or ethylene-propylene copolymers or natural fibers such as jute, to the tufted bounded layer of fibers 20 . The adhesive bonds the bounded layer of fibers 20 to the backing 30 .
[0076] To provide an eco-friendly artificial turf 10 in accordance with preferred embodiments of the present invention the bounded layer of fibers 20 , the tufts 40 , and the backing 30 may all be made of materials that are recyclable, such as, for example, 100% polyolefin.
[0077] Other arrangements for accomplishing the objectives of embodiments of the present invention will be obvious for those skilled in the art. It is to be understood that although preferred embodiments, specific constructions and configurations, as well as materials, have been discussed herein for devices according to the present invention, various changes or modifications in form and detail may be made without departing from the scope and spirit of this invention. | The present invention seeks to provide a tufted structure such as an artificial turf, that imitates more closely the root zone, the volume effect, and density of natural grass and that has an improved wear and drainage property. An artificial turf adapted for use in landscape and sports applications comprises a bounded layer of fibers formed as a non-woven matting made of one or more natural and/or synthetic fibers. A plurality of tufts of pile yarn is inserted through the bounded layer of fibers. A backing is applied at the backside of the bounded layer of fibers enhancing anchoring the tufts to the bounded layer of fibers. | 3 |
BACKGROUND OF THE INVENTION
The present invention relates generally to cement pumps, and more specifically to double acting cement pumps employing a pair of power driven, oppositely reciprocating pistons sliding in a pair of cylinders for the pumping action.
Reciprocating cement or concrete pumps are described in my U.S. Pat. Nos. 4,174,928 and 4,634,352. In U.S. Pat. No. 4,634,352, a cement pump of this type is described in which each cylinder outlet is connected to a respective pump response chamber having a valve controlled inlet for connection to a supply of cement or the like. The pump chamber outlets are each connected to a discharge chamber for controlling their connection to a delivery outlet, and a ball valve in the discharge chamber moves between the discharge chamber inlets to alternately isolate the flow of material from the two pump chambers in response to the pumping action.
The cement pump in my previous patents referred to above was of generally unitary construction. It is not easy to clear any clogged material from such an arrangement, and the ball valve seats in the discharge chamber will become worn relatively quickly, resulting in insufficient isolation of the pump chambers and inefficient pumping operation. Thus the entire pump must be replaced fairly often. Also, different jobs may require the use of pre-mixes having different water content, and therefore different viscosity. U.S. Pat. No. 4,634,352 described a pump in which the inlet valves could be readily adjusted for different viscosity materials. However, no adjustment of discharge or outlet valve was provided in this pump.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an improved cement pump.
According to the present invention a cement or concrete pump is provided which comprises first and second pump cylinders each containing a piston for reciprocating movement back and forth in the cylinder, a pump drive linked to the pistons for simultaneously sliding the pistons back and forth in opposite directions in the respective cylinders, a connecting manifold for connecting the respective cylinder outlets to a supply of flowable material to be pumped, the connecting manifold including first and second pumping chambers each having an inlet for connection to a respective one of the cylinder outlets, a feed inlet for connection to a supply of flowable material, and a discharge outlet for flow of pumped material out of the chamber, and a separate discharge manifold unit releasably securable to the connecting manifold for selectively connecting each of the pumping chamber outlets to a delivery outlet, the discharge manifold unit having a discharge chamber, and a control device for selectively connecting each of the pumping chamber outlets to the discharge chamber while isolating the other pumping chamber from the discharge chamber in response to pumping action of the respective pistons.
The discharge manifold unit is releasably securable to the remainder of the pump by any suitable securing device, for example it may be bolted to the connecting manifold. The outlet end of the connecting manifold and the discharge manifold unit preferably have co-operable mating formations for guided engagement of the discharge manifold unit with the connecting manifold. The discharge manifold unit or cartridge has a pair of inlet openings communicating with the discharge chamber and positioned for alignment with the respective pumping chamber outlets when the unit is secured to the connecting manifold.
The control device preferably comprises a ball valve located in the discharge chamber and moveable between valve seats at the respective inlet openings in response to the pumping action. The valve seats preferably comprise separate valve plate members designed to be sandwiched between opposing surfaces of the connecting manifold and discharge manifold when these two units are secured together. The members each have a projecting boss with a valve seat at its outer end designed to project through the respective inlet openings into the discharge chamber. Thus the valve seats can be replaced quickly and easily when worn or damaged.
Thus, by providing a separate discharge manifold unit or cartridge with releasably mounted valve seats on the double acting cement or concrete pump, the valve seats can be replaced when worn. Previously, the valve seats were generally not accessible and could not be replaced or repaired, so that the entire pump would have to be replaced when these parts became worn. The removable manifold also allows easy access to other adjacent parts of the pump in the case of any blockages or jams of the flowable material being pumped. Cement and other such water mixture materials tend to clog any device with which they come into contact, and if permitted to set can render the pump inoperative. The removable discharge manifold can be separated from the connecting manifold quickly and easily in the event of any clogging, allowing access to both the discharge chamber and the pumping chambers to clean out any clogged material.
Preferably, a number of different size valve balls will be provided for selective use in the discharge chamber with mixtures having different viscosities. The discharge manifold unit can be assembled on site with the selected valve ball size once the material characteristics have been determined. This will control the flow of material through the discharge chamber. Alternatively, valve seats having different bore sizes may be provided for use with materials having different flow characteristics. Thus the discharge chamber can be readily adjusted to accommodate different flow materials. Rather than having to provide several different pumps for different flow materials, the same basic pump can be used with the discharge chamber unit or cartridge being adjusted for materials having differing flow characteristics.
The pump of this invention is therefore easily adjusted, cleaned and maintained by the provision of a discharge manifold as a completely separate cartridge from the remainder of the pump.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be better understood from the following detailed description of a preferred embodiment of the invention, taken in conjunction with the accompanying drawings, in which like reference numerals refer to like parts, and in which:
FIG. 1 is a side elevation view of the cement pump structure according to a preferred embodiment of the present invention;
FIG. 2 is a sectional view taken on line 2--2 of FIG. 1;
FIG. 3 is a sectional view taken on line 3--3 of FIG. 1;
FIG. 4 is a sectional view taken on line 4--4 of FIG. 2;
FIG. 5 is a sectional view taken on line 5--5 of FIG. 1; and
FIG. 6 is an enlarged sectional view taken on line 6--6 of FIG. 4.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The drawings show a double acting pump for pumping premixed cement or concrete, or other similar flowable materials of mud-like viscosity, according to a preferred embodiment of the present invention. As seen in FIGS. 1 and 2, the pump is basically formed in three parts, consisting of a pumping section 10, a connecting manifold 12, and a discharge manifold or cartridge 14. The pumping section 10 is similar to that shown in my U.S. Pat. No. 4,634,352 referred to above and consists of a pair of reciprocating piston pumps 16,18 comprising pump cylinders 20,22 arranged horizontally in spaced parallel relationship, and a pair of pistons 24,26 which move with a reciprocating motion in the respective cylinders. The pistons are driven in opposite directions by a suitable drive assembly indicated schematically at 28. Cylinders 20,22 have outlets 30,32 (see FIG. 3),respectively at one end for connecting the pumps to a supply of fluid to be pumped and for discharging pumped fluid out of the cylinders.
Connecting manifold 12 connects the pump outlets to a supply of flowable material to be pumped via supply hopper 34. As in my previous U.S. Pat. No. 4,634,352 referred to above, the connecting manifold has two arms 36,38 connected to the respective pump outlets, with a respective pump response chamber 40,42 within each arm. Hopper 34 has a single rectangular outlet connection 44 which is connected to material inlets 46, 48 to the respective pump chambers 40 and 42, as best seen in FIGS. 2 and 5.
The flow of pre-mixed cement from the hopper to the cylinders 20 and 22 through the separate pump response chambers 40 and 42, respectively, is governed by the position of ball valves 50 and 52 within the respective chambers 40 and 42. The valves 50 and 52 are best seen in FIG. 5 and are moveable vertically between valve seats 54,56 at the respective inlets 46 and 48 and stops 58,60 which are adjustably mounted in the base of the respective chambers. The vertical position of the stops is adjustable by means of external adjustment knobs 62,64. Each pump response chamber 40,42 has a material flow outlet 66,68 for connection with the discharge manifold 14 as explained below.
The discharge manifold is in the form of a separate, butterfly wedge cartridge for releasable mating or wedging engagement with the outlet end of the connecting manifold. Preferably, as shown in FIGS. 2,3 and 4, the outlet end of the connecting manifold has a generally V- or wedge-like indent 70, and the inlet end of the discharge manifold is of corresponding V or wedge-like shape 72. Bolt-like threaded projections or pins 74 at the pointed end of manifold 14 extend through corresponding openings 76 in the wall of the connecting manifold and are secured by means of nuts 78 to lock the discharge manifold in position. Although cooperating V-shaped mating formations are provided on the connecting and discharge manifolds in the preferred embodiment shown in the drawings, other suitable cooperating formations may be used in alternative embodiments for mating engagement between the units.
The connecting manifold has a discharge chamber 80 at its V-shaped end with inlets 82,84 to the chamber 80 in the respective opposite faces of the wedge or V-shape for communication with corresponding outlets 66,68 from the respective pump response chambers, as illustrated in FIG. 3. The discharge chamber 80 has a single discharge outlet 86 connected to discharge outlet pipe 88 at the opposite end of the cartridge. The pipe 88 has a surge chamber connector 90 for connection to a surge chamber 92 for smoothing the output flow, and an outlet or supply opening 94 for connection to a flexible hose or the like for applying the cement in a standard fashion.
A discharge chamber isolation ball valve 96 within the discharge chamber is free to move generally horizontally within the chamber in response to material flow between annular valve seat members 98,100 at the respective inlets. A vertical stop or pin 102 is positioned at the discharge chamber outlet 86, as shown in FIGS. 3 and 4, to prevent loss of the valve ball 96 into the discharge pipe 88. Preferably, a boss 104 is provided in the base of chamber 80 to prevent the ball 96 from falling too low in the chamber and to keep it aligned with the valve seats.
Valve seat members 98,100 are preferably formed separately from the discharge manifold and comprise annular plates each having a through bore 106 and a projecting boss 108 which projects through the respective inlet opening into chamber 80, as shown in FIGS. 3 and 6. The valve seat members are sandwiched or gripped between the opposing faces of the wedge-shaped co-operating formations on the connecting manifold and discharge manifold, when the two units are secured together, as shown in FIGS. 3 and 6. Annular O-ring seals 110,112 are mounted on opposite faces of each of the valve seat members for sealing engagement with the respective opposed face of the connecting and discharge manifold, respectively. The inlet end of each boss is provided with a generally spherical annular valve seat 114 for seating the valve ball as shown in FIG. 6.
The operation of the cement pump is essentially the same as described in my previous U.S. Pat. No. 4,634,352 referred to above. Valve stops 58,60 will first be set for the viscosity of the material to be pumped, with the valve opening determined by the position of the respective stop. Thus the opening will be made larger for higher viscosity materials. With the separate discharge manifold of this invention, valve ball 96 can also be adjusted for different viscosity materials. For example, different size valve balls may be provided for controlling the flow of different viscosity materials, and valve seat members with different diameter bores 106 may also be provided.
When the desired adjustments have been made, the discharge manifold or wedge cartridge will be connected to the connecting manifold outlet, with the valve seat members in position between the two units. The drive assembly 28 can then be activated. The drawings illustrate a condition of the pump in which the piston 26 of pump 18 is undergoing a discharge stroke while the piston 24 of pump 16 is undergoing a suction stroke. The suction created in cylinder 20, and thus in chamber 40, causes the valve ball 50 to be drawn away from valve seat 54, allowing cement to be withdrawn from the hopper, through the pump response chamber 40, and into cylinder 20. At the same time, cement flow out of cylinder 22 into pump response chamber 42 forces valve ball 52 against valve seat 56 to close the material inlet. The pressurized cement then flows through outlet 68, valve seat member 100, and into the discharge chamber 80, forcing valve ball 96 against the opposite valve seat of member 98, to isolate the other pump response chamber from the discharge manifold. Pressurized cement is then supplied along discharge pipe 88 to a suitable supply hose or the like. When the pistons 24,26 reverse on the next stroke of the pump, the opposite effect occurs, with valve ball 52 moving away from valve seat 56 while valve ball 50 closes, and valve ball 96 moving across to the opposite valve seat member 100.
In the event of any blockage, the discharge unit or cartridge can be removed to allow access to both the pump response chambers and the discharge chamber for cleaning. Another advantage is that the valve seat members can be replaced when the seats become too worn to provide an effective seal. The ball valve 96 is relatively heavy and is forced against the valve seats repeatedly under considerable pressure, leading to the seats becoming worn relatively quickly, resulting in an inefficient pumping operation. In the past this has involved replacement of the entire pump assembly fairly frequently, for example as often as every 6 months. With this invention the valve seat members can be replaced quickly and easily, considerably increasing the effective lifetime of a pump installation.
Thus the cement pump described above with a separable discharge manifold or wedge cartridge allows access to the various chambers for washing out of the assembly in the event of jams or blockages. Also, the valve openings of the discharge chamber can be adjusted quickly and easily for different viscosity materials, for example by providing a series of different size ball valves for use in the chamber. Alternatively, or additionally, valve seat members having different diameter through bores may be provided. The valve seat members can be removed and replaced quickly and easily when worn, increasing the lifetime of the pump.
Although a preferred embodiment of the invention has been described above by way of example only, it will be understood by those skilled in the field that modifications may be made to the disclosed embodiment without departing from the scope of the invention, which is defined by the appended claims. | A double acting concrete pump includes a pair of pump cylinders with a piston slidable back and forth in each cylinder, the pistons being driven in opposite directions, a connecting manifold connecting each of the cylinder outlets to a source of cement via separate pumping chambers, and a separate, removable discharge manifold for connecting the pumping chamber outlets to a delivery outlet. The discharge manifold has a discharge chamber with a pair of inlets connected to the respective pumping chamber outlets, and a single discharge outlet, with an outlet control valve in the discharge chamber for alternately isolating the flow from each of the pumping chambers to the discharge outlet in response to the pumping action. | 8 |
TECHNICAL FIELD
The instant invention relates to the use of lutein compounds as brightening agents in thermally processed nutritional formulas.
BACKGROUND OF THE INVENTION
Historically, man has used color as an indication of the safety and quality of harvested fruits, vegetables and other foods. Present day customers expect processed foods to be colored attractively and with shades that are typical of their flavor variety. The first perception of a food product is its appearance and this leads to an expectation that is compatible with that which is seen. So strong is the expectation that it is possible to over-ride subsequent sensory perceptions. In judging the quality and consistency of a product, the consumer is strongly influenced by its appearance.
The color production industry aims to meet food and drink manufacture's needs by providing a full range of colors to suit all applications, within current legislative constraints. Consumer pressure, sociological changes and technological developments leading to more advances in the food processing industry have increased the overall color market. The most significant growth has been in naturally derived colors owing to the improvements in stabilization technologies as well as the food industry's aim to meet the evolving consumer perception that natural is best.
Synthetic colors, natural colors, nature identical colors, and caramel colors are the primary colorants used to color foods. Currently, the permitted synthetic pigments are in the form of water-soluble dyes. Although cited as having excellent stability, soluble dyes do lose their color in certain characteristics food manufacturing circumstances. The most common problems with soluble dyes include: decolorization by ascorbic acid; loss of color resulting from microbial attack; precipitation/color loss resulting from the presence of metal ions; masking due to formation of maillard reaction products and reaction with proteins at high temperatures causing color fade.
Likewise, caramel colors also constitute a significant segment of the overall color market principally owing to their use in cola beverage drinks. They are produced by the controlled heating of carbohydrates such as sucrose, glucose and fructose. Four classes of caramels are commercially produced for specific applications. They differ in the catalyst used to promote the caramelization process.
Nature-identical colors have been developed to match their counterparts in nature. Carotenoids are one of the most common pigments that are synthesized. Carotenoids contain conjugated hydrocarbons and are therefore prone to oxidative attack and a subsequent loss of color. Color formulations containing carotenoids have been developed with antioxidant systems to reduce this effect. For most food and drink applications, the challenge to the suppliers is to provide oil and water dispersible forms of carotenoids. This is achieved using methods such as encapsulation, emulsification and pigment suspension. By using these methods, carotenoid water and oil dispersible nature-identical colors with wide-ranging pigment contents have been developed. The shade achieved with synthesized carotenoids is dependent on the formulation and processing used and varies from golden yellow to a red/orange shade.
Significant demand for natural colorants has developed over the past 25 years. The growth in use of natural colors comes from increasing consumer pressure for “natural” products. Color is spread widely throughout nature in fruit, vegetables, seeds and roots. In our daily diets, we consume large quantities of many pigments, especially anthocyanins, carotenoids and cholorophylls. Pigments from nature vary widely in their physical and chemical properties. Many are sensitive to heat, oxidation, pH change, light and their inherent solubility varies widely. With these drawbacks in mind, suppliers of natural colors have focused on the development of currently permitted pigments in three main areas: formulation technology; processing technology; and alternative sources of pigments. These approaches have proved very successful and have contributed to the increase in usage of natural colors throughout the food and drink industry.
The xanthophyll lutein is a naturally derived pigment and until recently permitted only in chicken feed in the U.S. Lutein provides color ranging from golden yellow to red/yellow. Lutein has recently been self-affirmed as GRAS (general recognized as safe) for certain food formulations, in accordance with Food and Drug Administration guidelines. Lutein is a naturally occurring oxygenated carotenoid that has no vitamin A activity. There are three asymmetric centers in lutein at C-3, C-3′ and C-6′ positions. The absolute configuration of lutein in foods is known to be 3R,3′R,6′R. Lutein is found in corn, green leafy vegetables such as spinach, kale and broccoli, and yellow-orange fruits such as peaches. Its molecular structure demonstrates its highly-conjugated carotenoid nature and its structural similarity to beta-carotene.
Like many other carotenoids, lutein also occurs in nature as esters of fatty acids. Lutein esters are common carotenoids found in fruits such as oranges, tangerines, peaches, mangos and yellow and red peppers. Both lutein and lutein esters are fat-soluble.
In addition to the green leafy vegetables described above, lutein is found in egg yolks and in some flowers. It has been recognized as an antioxidant, which may protect against macular degeneration, a leading cause to blindness among the elderly. Commercially, it is usually extracted from the petals of the Aztec marigold. Lutein, especially when in purified form, provides a yellow to orange shade. Traditionally marigold flowers and the saponified oleoresin have been used in poultry feed to impart yellow/orange color in egg yolk. The carotenoid composition of marigold oleoresin typically contains 70% trans-lutein, 20% cis-lutein, 7% zeaxanthin, 0.58% epoxides, 1.02% unsaponifiables and 1.4% others.
Zeaxanthin, a stereoisomer of lutein, is typically found in combination with lutein and as described in Torres-Cardona et.al. below contributes a more orange color.
U.S. Pat. No. 5,997,922 to Torres-Cardona et.al. discloses the addition of 10 to 55 ppm of saponified marigold extract to poultry feed to enhance the yellow/orange pigmentation of broiler skin and egg yolk. The saponified marigold extract has a zeaxanthin content between about 20% and 80% of the total xanthophylls.
U.S. Pat. No. 3,539,686 to Rosenberg demonstrated that it is possible to obtain a wide range of tones going from yellow to red hues in broiler skin and egg yolk by using blends of xanthophylls or zeaxanthin with one or more pigments such as cantaxanthin, beta-apo-8-carotenal, ethyl ester of the beta-apo-8-carotenoic acid, and extracts from paprika and red peppers.
U.S. Pat. No. 5,382,714 to Khachik describes a process of isolating, purifying and recrystallizing substantially pure lutein apart from chemical impurities and other carotenoids for use in cancer prevention and as a safe and effective color additive for human food. The purified lutein from marigold flowers consists of 94.79% of all E-lutein, 3.03% of its geometrical isomers (Z-lutein), and a total of 2.18% of 2′,3′-anhydrolutein, zeaxanthin, alpha-cryptoxanthin and beta-cryptoxanthin.
U.S. Pat. No. 5,648,564 to Ausich et al. describes a process for forming, isolating and purifying xanthophyll crystals suitable for human consumption.
U.S. Pat. No. 6,221,417 to Sas et al. describes an in situ process for converting non-free-form xanthophylls to free xanthophylls in the biological material of the plant. The free-form xanthophylls (7.5 mg of lutein activity per kg of feed) are used to enhance the yellow color of egg yolk.
As discussed above, color is the first attribute a consumer sees of a food product. The consumer sets expectations based on their experience with the product itself, such as the yellow of egg yolks and the name given to the product, such as the creamy color with black flecks of a French vanilla ice cream. Therefore, processed foods must be colored attractively and with shades that are typical of their flavor variety. If appearance is not compatible with the expectations of the consumer, the overall appeal of the product is diminished even if the flavor is superior.
A thermally processed nutritional product's color is the result of the colors contributed by the individual ingredients as well as the numerous ingredient interactions that occur in the final product. For example, caseinates are involved in the development of color. Amino acids react with reducing sugars in the nonenzymatic browning reaction (Maillard reaction) to produce caramel-like colors and cooked flavors. Typically, the more heat a nutritional receives during processing, the more ingredient interactions occur which often produce undesirable colors, including brown and gray. The color changes from these heat-induced reactions are illustrated in FIG. 1 . The nutritional mix prior to sterilization ( 1 A) is a bright white. However, after thermal processing in a can ( 1 B) or glass bottle ( 1 C) the color changes. The once white mix now presents brown and gray hues. The brown and gray colors of a vanilla flavored nutritional do not closely meet the expectations of the consumer and detract from the product's appeal to the consumer.
Clearly, a brightening agent is required that can mask the brown and gray hues of thermally processed nutritional products. The brighter color would enhance the overall sensory acceptability of the product by the consumer.
SUMMARY OF THE INVENTION
In accordance with the present invention, it has been discovered that the addition of lutein compounds to the nutritional mix prior to thermal processing brightens the product and results in a more appealing color. Thermal processing of liquid and powder nutritionals typically impart brown and gray hues to the final color, which negatively impact the overall appeal of the nutritional. The inventors have discovered that the lutein compounds eliminate the gray and brown hues without imparting the relatively strong yellow color typically associated with lutein compounds. Additionally, the nutritionals possess long-term color stability.
Based on prior enhancement work done with lutein compounds in egg yolk, the inventors expected the supplemental lutein to add an undesirable yellow color to the vanilla, strawberry and chocolate flavored/colored nutritionals. This was further supported by statements from the supplier, Kemin Foods (Lutein a treat for the eyes, Food Processing's Wellness Foods, August 2001), that lutein could impact color in clear or white beverages. Surprisingly, the lutein brightened the appearance of the nutritionals by masking the typical brown and gray hues of thermally processed nutritionals without the addition of a strong yellow color. This finding was unexpected in light of the use of similar levels of lutein compounds in earlier color enhancement work done in broiler skin and egg yolk, wherein the yellow/orange of the egg yolk was enhanced by the addition of 7.5 ppm to 55 ppm of lutein compounds to poultry feed.
BRIEF DESCRIPTION OF THE FIGURES
The file of this patent contains at least one drawing executed in color. Copies of this patent with color drawing(s) will be provided by the Patent and Trademark Office upon request and payment of the necessary fee.
FIG. 1 is a photo of three samples: 1 A) the homogenized lutein free mix prior to thermal processing; 1 B) the lutein free mix thermally processed in a metal can; and 1 C) the lutein free mix thermally processed in a glass bottle.
FIG. 2 is a photo of two samples: E 1 ) the thermally processed vanilla flavored control without lutein added; and 9 C) the thermally processed unflavored mix with 1.026 mg lutein/8 fl.oz.
FIG. 3 is a photo of two samples: E 1 ) the thermally processed vanilla flavored control without lutein added; and 9-2) the thermally processed unflavored mix with 0.622 mg lutein/8 fl.oz.
FIG. 4 is a photo of two samples: SE 2 ) the thermally processed strawberry flavored/colored mix with 0.827 mg/8 fl.oz; and the thermally processed strawberry flavored/colored control without lutein added.
FIG. 5 is a photo of two samples: EC 1 ) the thermally processed chocolate flavored/colored control without lutein added; and EC 2 ) the thermally processed chocolate flavored/colored mix with 1.121 mg/8 fl.oz.
DETAILED DESCRIPTION
As discussed above, lutein is an oxygenated carotenoid, a xanthophyll, found in corn, green leafy vegetables and yellow-orange fruits and has the following formula (I):
Forumula (I) describes the chemical structure of the lutein compounds referred to in the present invention. As used herein, free lutein comprises the structure of formula (I) wherein R 1 and R 2 are simultaneously H. Additionally, free lutein may be in cis and trans geometrical isomeric forms. Further, the free lutein of the invention may exist as nutritionally acceptable monovalent cation salts which include, but are not limited to lithium, sodium and potassium (see Table 1).
TABLE 1
Lutein Compounds
Lutein Compound
R 1
R 2
Free Lutein
H
H
Lutein monoester
H
fatty carboxylic acid*
Lutein monoester
fatty carboxylic acid*
H
Lutein diester
fatty carboxylic acid*
fatty carboxylic acid*
(homogenous)
of R 2
of R 1
Lutein diester
A different fatty
A different fatty
(mixed)
carboxylic acid* from R 2
carboxylic acid* from R 1
Lutein salt
Monovalent salts**
Monovalent salts**
*Saturated or unsaturated C 1 to C 22 fatty carboxylic acids includes, but not limited to acetic, butyric, caproic, capric, caprylic, formic, lauric, myristic, oleic, palmitic, propionic, stearic and valeric acids.
**monovalent salts include, but not limited to lithium, sodium and potassium.
As used herein, lutein ester refers to any lutein ester of formula (I) wherein R 1 and R 2 are the same or different, and are nutritionally acceptable monovalent salts, H or an acyl residue of a carboxylic acid, provided that at lest one of R 1 or R 2 is an acyl residue of a carboxylic acid. Additionally, the lutein ester may be in cis and trans geometrical isomeric forms. Further, R 1 and R 2 are the residue of a saturated or unsaturated C 1 to C 22 fatty carboxylic acids, which include, but are not limited to formic, acetic, propionic, butyric, valeric, caproic, caprylic, capric, lauric, myristic, palmitic, stearic, and oleic acids.
Free lutein (C 40 H 56 O 2 ) has a molecular weight of approximately 568 a.m.u. and lutein esters typically have molecular weights of 568 plus the molecular weight of the attached residue of a saturated or unsaturated C 1 to C 22 fatty carboxylic acids. For example, the molecular weight of dipalmitate lutein ester (C 72 H 116 O 4 ) is approximately 1044 a.m.u. It is understood in the art that 2.0 gram of lutein esters and 1.0 gram of free lutein represent the same total free lutein content. Similarly, the molecular weight of lutein salts is also increased by the molecular weight contribution of the salts. In this situation, the salt contribution is subtracted to determine the total free lutein content.
As discussed above, zeaxanthin is a stereoisomer of lutein, is typically found in combination with lutein and has the following formula (II):
Formula II describes the structure of the zeaxanthin compounds referred to in the present invention. As used herein, free zeaxanthin comprises the structure of formula (II) wherein R 1 and R 2 are simultaneously H. Additionally, free zeaxanthin may be in cis and trans geometrical isomeric forms. Further, the free zeaxanthin of the invention may exist as nutritionally acceptable monovalent cation salts which include, but are not limited to lithium, sodium and potassium (see Table 2).
TABLE 2
Zeaxanthin compounds
Zeaxanthin Compound
R 1
R 2
Free Zeaxanthin
H
H
Zeaxanthin monoester
H
fatty carboxylic acid*
Zeaxanthin monoester
fatty carboxylic acid*
H
Zeaxanthin diester
fatty carboxylic acid*
fatty carboxylic acid*
(homogenous)
of R 2
of R 1
Zeaxanthin diester
A different fatty
A different fatty
(mixed)
carboxylic acid*
carboxylic acid*
from R 2
from R 1
Zeaxanthin salt
Monovalent salts**
Monovalent salts**
*Saturated or unsaturated C 1 to C 22 fatty carboxylic acids includes, but not limited to acetic, butyric, caproic, capric, caprylic, formic, lauric, myristic, oleic, palmitic, propionic, stearic and valeric acids.
**monovalent salts include, but not limited to lithium, sodium and potassium.
As used herein, zeaxanthin ester refers to any zeaxanthin ester of formula (II) wherein R 1 and R 2 are the same or different and are nutritionally acceptable monovalent salts, H or an acyl residue of a carboxylic acid, provided that at least one of R 1 or R 2 is an acyl residue of a carboxylic acid. Additionally, the zeaxanthin ester may be in cis and trans geometrical isomeric forms. Further, R 1 and R 2 are the residue of a saturated or unsaturated C 1 to C 22 fatty carboxylic acids, which include, but are not limited to formic, acetic, propionic, butyric, valeric, caproic, caprylic, capric, lauric, myristic, palmitic, stearic, and oleic acids.
Zeaxanthin (C 40 H 56 O 2 ) has a molecular weight of approximately 568 a.m.u. and zeaxanthin esters typically have molecular weights of 568 plus the molecular weight of the attached residue of a saturated or unsaturated C 1 to C 22 fatty carboxylic acids. For example, the molecular weight of dipalmitate zeaxanthin ester (C 72 H 116 O 4 ) is approximately 1044 a.m.u. It is understood in the art that 2.0 gram of zeaxanthin esters and 1.0 gram of free zeaxanthin represent the same total free zeaxanthin content. Similarly, the molecular weight of zeaxanthin salts is increased by the molecular weight contribution of the salts. In this situation, the salt contribution is subtracted to determine the total free zeaxanthin content.
Brightening agents and lutein compounds are used interchangeable herein and refer to any combination of free lutein, nutritionally acceptable salts of free lutein and the cis and trans isomeric form of each; lutein esters in cis and trans isomeric forms; stereoisomers such as free zeaxanthin, nutritionally acceptable salts of zeaxanthin and the cis and trans isomeric form of each; zeaxanthin esters in cis and trans isomeric forms; along with other minor carotenoids being present as a result of the natural abundance of the source as well as those formed during the process of manufacture.
As used herein the term nutritionally acceptable salt refers to the monovalent cation salt of free lutein, lutein ester, free zeaxanthin and zeaxanthin ester, or combinations thereof. Nutritionally acceptable monovalent cation salts include, but are not limited to lithium, sodium and potassium.
As used herein the term isomeric form refers to cis isomers of free lutein, lutein esters, lutein salts, free zeaxanthin, zeaxanthin ester and zeaxanthin salts; or trans isomers of free lutein, lutein esters, lutein salts, free zeaxanthin, zeaxanthin ester and zeaxanthin salts; or a combination thereof.
Total lutein refers to the total amount of lutein and lutein equivalents within a nutritional. Typically, it is understood that 2.0 gram of zeaxanthin esters or lutein esters and 1.0 gram of free zeaxanthin or free lutein represent the same total lutein content.
Total lutein in nutritional products of the present invention may be analyzed by the methods described in Nguyen, M. L., Francis, D. M. and Schwartz, S. J., Thermal isomerization susceptibility of carotenoids in different tomato varieties. Journal of the Science of Food and Agriculture, 2001, 81, 910-917 and Emenhiser, C., Sander, L. C., and Schwartz, S. J. 1995. Capability of a polymeric C 30 stationary phase to resolve cis-trans carotenoid isomers in reversed-phase liquid chromatography. Journal Chromatography A. 707, 205-216.
Hunter Color refers to color analyzed by the Hunter ColorQuest 45/0 system spectrocolorimeter, which measures color the way the human eye sees color. The instrument is configured to measure reflectance using Hunter “Lab” scale, Illuminant C and a 2° observer. The basic principle revolves around a three-dimensional graph with axes “L”, “a” and “b” all crossing at point 0.00. The “L” value measures lightness (100.00) to darkness (0.00). The “a” value measures red when the result is a positive number, gray when 0.00 and green when the result is negative. The “b” value measures yellow when the result is a positive number, gray when 0.00 and blue when the result is negative.
Nutritionals, nutritional formulas, enteral nutritionals and thermally-processed enteral nutritionals are used interchangeable herein and refer to thermally-processed liquid and powder forms of enteral formulas, oral formulas, formulas for adults, formulas for pediatric patients and formulas for infants, which may be used as a supplement to the diet or sole source of nutrition.
The present invention provides methods and compositions for brightening the color of thermally processed nutritionals by adding brightening agents to mask the typical brown and gray hues of thermally processed nutritionals.
As described earlier, free lutein, lutein esters, zeaxanthin and zeaxanthin esters for use in the present invention may be readily extracted from plant materials using known methods. The lutein compounds of the instant invention may be derived from the petals of the marigold flower, Tagetes erecta. The marigolds T. grandiflora, T. patula, and T. nana Ehrenkreutz are also suitable sources for lutein compounds. In a typical process, the marigold flowers are harvested, dried, and milled. The milled marigolds are extracted with a food grade solvent. The carotenoid fraction is then concentrated, for example, by solvent removal through vacuum distillation. Alternatively, the lutein and zeaxanthin esters may be synthesized by any means known in the art to the skilled practitioner, e.g., via esterification from free lutein and zeaxanthin.
Suitable food grade lutein/zeaxanthin and lutein/zeaxanthin esters are commercially available in different presentations such as oil soluble and water dispersible systems, spray derived emulsions, gum-based emulsions and emulsifier-based emulsions. The lutein/zeaxanthin ester of the present invention can be any mono- or diester, homogeneous or mixed. Suitable esters therefore include lutein/zeaxanthin mono- or diformate, mono- or diacetate, mono- or dipropionate, mono- or dibutyrate, mono- or divalerate, mono- or dicaproate, mono- or dicaprylate, mono- or dicaprate, mono- or dilaurate, mono- or dimyristate, mono- or dipalmitate, mono- or distearate, and mono- or dioleate, as well as mixed esters such as lutein myristate-palmitate and palmitate-stearate.
The carotenoid composition of the standard source material, marigold oleoresin, typically contains 70% trans-lutein, 20% cis-lutein, 7% zeaxanthin, 0.58% epoxides, 1.02% unsaponifiables and 1.4% others. The skilled practitioner may enrich the levels of individual xanthophyll compounds in the source material through any means known in the art, e.g., via hydrocarbon solvent extraction. Purified xanthophyll compositions useful for the instant invention typically comprise a total of cis and trans free lutein from about 10 wt/wt % to 99 wt/wt % of the xanthophyll composition; more preferably from about 40 wt/wt % to 99 wt/wt % of the xanthophyll composition; preferably from about 90 wt/wt % to 99 wt/wt % of the xanthophyll composition; and a total of cis and trans zeaxanthin from about 1 wt/wt % to 90 wt/wt % of the xanthophyll composition; more preferably from about 1 wt/wt % to 60 wt/wt % of the xanthophyll composition; preferable from about 1 wt/wt % to 10 wt/wt % of the xanthophyll composition. Similar ranges are typical of isolated xanthophyll esters or when the purified xanthophyll composition of above is esterified to form lutein and zeaxanthin esters.
Xanthophyll compounds are available commercially. For example, free lutein/zeaxanthin may be obtained in an oil suspension and beadlet form from Kemin Foods of Des Moines, Iowa distributed as FloraGLO® lutein. Lutein/zeaxanthin esters may also be obtained in an oil suspension and beadlet form. Cognis Corporation of LaGrange, Ill. distributes Xangold™ natural lutein esters in 15% oil suspension or 10% beadlets. A typical profile of Xangold™ 15% oil lutein esters contains 139,500 mcg/gm of lutein esters, 9,750 mcg/gm zeaxanthin esters and 750 mcg/gm cryptoxanthin esters. A typical profile of Xangold™ 10% beadlets contains 93,000 mcg/gm lutein esters and 7,000 mcg/gm zeaxanthin esters.
An effective amount of total lutein to brighten the reconstituted powder and liquid nutritionals of the instant invention is from about 0.2 ppm to about 60 ppm, preferably from about 0.5 ppm to about 12 ppm, more preferably from about 1 ppm to about 5 ppm.
Alternatively, an effective amount of total lutein to brighten the reconstituted powder and liquid nutritionals of the present invention is from about 0.002 wt/vol % to about 0.63 wt/vol %, preferably from about 0.005 wt/vol % to about 0.12 wt/vol %, more preferably from about 0.01 wt/vol % to about 0.055 wt/vol %.
Further, an effective amount of lutein/zeaxanthin esters to brighten reconstituted powder and liquid nutritionals are from about 0.5 ppm to about 125 ppm, preferably from about 1 ppm to about 25 ppm, more preferably from about 2 ppm to about 10 ppm.
The total lutein ranges above typically correspond to about 0.050 mg per 8 fl.oz. to about 15 mg per 8 fl.oz., preferably from about 0.125 mg per 8 fl.oz. to about 3 mg per 8 fl.oz., more preferably from about 250 mg per 8 fl.oz. to about 1.3 mg per 8 fl.oz.
Alternatively, an effective amount of lutein compounds to brighten reconstituted powder and liquid enteral nutritionals may be an amount sufficient to shift the Hunter values toward the +b axes of the three-dimensional graph. For example, “+a” values decrease toward 0.0; “−b” values increase toward 0.0; “−a” values increase toward 0.0; “+b” values increase away from 0.0 and combinations thereof.
As noted above, lutein compounds may be added to nutritional products as a brightening agent. The quantity of lutein compounds that are incorporated into the nutritional can vary widely, but will fit into the guidelines described above. The amount of lutein compounds utilized in a nutritional formula will be dependent upon various factors including the form of the nutritional and lutein/zeaxanthin compound form. The formula will preferably contain lutein compounds in an amount sufficient to provide a brighter color as measured by Hunter Color analysis.
Nutritional formulas include enteral formulas, oral formulas, formulas for adults, formulas for pediatric individuals and formulas for infants. Nutritional formulas contain a protein component, providing from 5 to 80% of the total caloric content of the formula, a carbohydrate component providing from 10 to 70% of the total caloric content, and a lipid component providing from 5 to 50% of the total caloric content. The nutritional formulas described herein may be used as a supplement to the diet or sole source of nutrition. The amount of calories and nutrients required will vary from person to person, dependent upon such variables as age, weight, and physiologic condition. The amount of nutritional formula needed to supply the appropriate amount of calories and nutrients may be determined by one of ordinary skill in the art, as may the appropriate amount of calorie and nutrients to incorporate into such formulas.
As examples, when the formula is an adult formula, the protein component may comprise from about 10 to about 80% of the total caloric content of said nutritional formula; the carbohydrate component may comprise from about 10 to about 70% of the total caloric content of said nutritional formula; and the lipid component may comprise from about 5 to about 50% of the total caloric content of said nutritional formula. The nutritional formula may be in liquid or powder form.
As another example, when the formula is a non-adult formula, the protein component may comprise from about 8 to about 25% of the total caloric content of said nutritional formula; the carbohydrate component may comprise from about 35 to about 50% of the total caloric content of said nutritional formula; and the lipid component may comprise from about 30 to about 50% of the total caloric content of said nutritional formula. These ranges are provided as examples only, and are not intended to be limiting.
The nutritional formulas will contain suitable carbohydrates, lipids and proteins as is known to those skilled in the art of making nutritional formulas. Suitable carbohydrates include, but are not limited to, hydrolyzed, intact, naturally and/or chemically modified starches sourced from corn, tapioca, rice or potato in waxy or non waxy forms; and sugars such as glucose, fructose, lactose, sucrose, maltose, high fructose corn syrup, corn syrup solids, fructooligosaccharides, and mixtures thereof.
Suitable lipids include, but are not limited to, coconut oil, soy oil, corn oil, olive oil, safflower oil, high oleic safflower oil, MCT oil (medium chain triglycerides), sunflower oil, high oleic sunflower oil, palm oil, palm olein, canola oil, cottonseed oil, fish oil, palm kernel oil, menhaden oil, soybean oil, lecithin, lipid sources of arachidonic acid and docosahexaneoic acid, and mixtures thereof. Lipid sources of arachidonic acid and docosahexaneoic acid include, but are not limited to, marine oil, egg yolk oil, and fungal or algal oil.
Numerous commercial sources for these fats are readily available and known to one practicing the art. For example, soy and canola oils are available from Archer Daniels Midland of Decatur, Ill. Corn, coconut, palm and palm kernel oils are available from Premier Edible Oils Corporation of Portland, Oreg. Fractionated coconut oil is available from Henkel Corporation of LaGrange, Ill. High oleic safflower and high oleic sunflower oils are available from SVO Specialty Products of Eastlake, Ohio. Marine oil is available from Mochida International of Tokyo, Japan. Olive oil is available from Anglia Oils of North Humberside, United Kingdom. Sunflower and cottonseed oils are available from Cargil of Minneapolis, Minn. Safflower oil is available from California Oils Corporation of Richmond, Calif.
In addition to these food grade oils, structured lipids may be incorporated into the nutritional if desired. Structured lipids are known in the art. A concise description of structured lipids can be found in INFORM, Vol. 8, no. 10, page 1004, entitled Structured lipids allow fat tailoring (October 1997). Also see U.S. Pat. No. 4,871,768, which is hereby incorporated by reference. Structured lipids are predominantly triacylglycerols containing mixtures of medium and long chain fatty acids on the same glycerol nucleus. Structured lipids and their use in enteral formula are also described in U.S. Pat. Nos. 6,194,37 and 6,160,007, the contents of which are hereby incorporated by reference.
Suitable protein sources include, but not limited to, milk, whey and whey fractions, soy, rice, meat (e.g., beef), animal and vegetable (e.g., pea, potato), egg (egg albumin), gelatin and fish. Suitable intact protein sources include, but are not limited to, soy based, milk based, casein protein, whey protein, rice protein, beef collagen, pea protein, potato protein, and mixtures thereof. Suitable protein hydrolysates include, but are not limited to, soy protein hydrolysate, casein protein hydrolysate, whey protein hydrolysate, rice protein hydrolysate, potato protein hydrolysate, fish protein hydrolysate, egg albumen hydrolysate, gelatin protein hydrolysate, a combination of animal and vegetable protein hydrolysates, and mixtures thereof.
Protein may also be provided in the form of free amino acids. The nutritional formulas may be supplemented with various amino acids in order to provide a more nutritionally complete and balanced formula. Examples of suitable free amino acids include, but are not limited to, all free L-amino acids usually considered a part of the protein system, but especially those considered essential or conditionally essential from a nutritional standpoint, namely: tryptophan, tyrosine, cyst(e)ine, methionine, arginine, leucine, valine, lysine, phenylalanine, isoleucine, threonine, and histidine. Other (non-protein) amino acids typically added to nutritional products include carnitine and taurine. In some cases, the D-forms of the amino acids are considered as nutritionally equivalent to the L-forms, and isomer mixtures are used to lower cost (for example, D,L-methionine).
The nutritional formulas preferably also contain vitamins and minerals in an amount designed to supply or supplement the daily nutritional requirements of the person receiving the formula. Those skilled in the art recognize that nutritional formulas often include overages of certain vitamins and minerals to ensure that they meet targeted level over the shelf life of the product. These same individuals also recognize that certain microingredients may have potential benefits for people depending upon any underlying illness or disease that the patient is afflicted with. For example, diabetics benefit from such nutrients as chromium, carnitine, taurine and vitamin E. Formulas preferably include, but are not limited to, the following vitamins and minerals: calcium, phosphorus, sodium, chloride, magnesium, manganese, iron, copper, zinc, selenium, iodine, chromium, molybdenum, conditionally essential nutrients m-inositol, carnitine and taurine, and Vitamins A, C, D, E, K and the B complex, and mixtures thereof.
If the nutritional is intended for an infant, then specific nutritional guidelines may be found in the Infant Formula Act, 21 U.S.C. section 350(a). The nutritional guidelines found in these statutes continue to be refined as further research concerning nutritional requirements is completed. The nutritional formulas claimed are intended to encompass formulas containing vitamins and minerals that may not currently be listed.
The nutritional formulas also may contain fiber and stabilizers. Suitable sources of fiber/and or stabilizers include, but are not limited to, xanthan gum, guar gum, gum arabic, gum ghatti, gum karaya, gum tracacanth, agar, furcellaran, gellan gum, locust bean gum, pectin, low and high methoxy pectin, oat and barley glucans, carrageenans, psyllium, gelatin, microcrystalline cellulose, CMC (sodium carboxymethylcellulose), methylcellulose hydroxypropyl methyl cellulose, hydroxypropyl cellulose, DATEM (diacetyl tartaric acid esters of mono- and diglycerides), dextran, carrageenans, FOS (fructooligosaccharides), and mixtures thereof. Numerous commercial sources of soluble dietary fibers are available. For example, gum arabic, hydrolyzed carboxymethylcellulose, guar gum, pectin and the low and high methoxy pectins are available from TIC Gums, Inc. of Belcamp, Md. The oat and barley glucans are available from Mountain Lake Specialty Ingredients, Inc. of Omaha, Nebr. Psyllium is available from the Meer Corporation of North Bergen, N.J. while the carrageenan is available from FMC Corporation of Philadelphia, Pa.
The fiber incorporated may also be an insoluble dietary fiber representative examples of which include oat hull fiber, pea hull fiber, soy hull fiber, soy cotyledon fiber, sugar beet fiber, cellulose and corn bran. Numerous sources for the insoluble dietary fibers are also available. For example, the corn bran is available from Quaker Oats of Chicago, Ill.; oat hull fiber from Canadian Harvest of Cambridge, Minn.; pea hull fiber from Woodstone Foods of Winnipeg, Canada; soy hull fiber and oat hull fiber from The Fibrad Group of LaVale, Md.; soy cotyledon fiber from Protein Technologies International of St. Louis, Mo.; sugar beet fiber from Delta Fiber Foods of Minneapolis, Minn. and cellulose from the James River Corp. of Saddle Brook, N.J.
A more detailed discussion of examples of fibers and their incorporation into formula may be found in U.S. Pat. No. 5,085,883 issued to Garleb et al, which is hereby incorporated by reference.
The quantity of fiber utilized in the formulas can vary. The particular type of fiber that is utilized is not critical. Any fiber suitable for human consumption and that is stable in the matrix of a nutritional formula may be utilized.
In addition to fiber, the nutritionals may also contain oligosaccharides such as fructooligosaccharides (FOS) or glucooligosaccharides (GOS). Oligosaccharides are rapidly and extensively fermented to short chain fatty acids by anaerobic microorganisms that inhabit the large bowel. These oligosaccharides are preferential energy sources for most Bifidobacterium species, but are not utilized by potentially pathogenic organisms such as Clostridium perfingens, C. difficile, or Eschericia coli.
The nutritional formulas may also contain a flavor to enhance its palatability. Useful flavorings include, but are not limited to, chocolate, vanilla, coffee, peach, butter pecan, blueberry, banana, cherry, orange, grape, fruit punch, bubble gum, apple, raspberry and strawberry. Artificial sweeteners may be added to complement the flavor and mask salty taste. Useful artificial sweeteners include saccharin, nutrasweet, sucralose, acesulfane-K (ace-K), etc..
Nutritional formulas can be manufactured using techniques well known to those skilled in the art. Various processing techniques exist. Typically these techniques include formation of a slurry from one or more solutions which may contain water and one or more of the following: carbohydrates, proteins, lipids, stabilizers, vitamins and minerals. The slurry is emulsified, homogenized and cooled. Various other solutions may be added to the slurry before processing, after processing or at both times. The processed formula is then sterilized and may be diluted to be dried to a powder, utilized on a ready-to-feed basis or packaged in a concentrated liquid form. When the resulting formula is meant to be a ready-to-feed liquid or concentrated liquid, an appropriate amount of water would be added before sterilization.
EXAMPLE I
Table 3 presents a bill of materials for manufacturing 1,000 kg of a typical vanilla flavored liquid nutritional product containing the brightening agent lutein. A detailed description of its manufacture follows.
TABLE 3
Bill of Materials for Vanilla Liquid Nutritional with Lutein
Ingredient
Quantity per 1,000 kg
Water
QS
Corn Syrup
33
kg
Maltodextrin
28
kg
Sucrose
19.4
kg
Caseinate
8.7
kg
High Oleic Safflower Oil
4.1
kg
Canola Oil
4.1
kg
Soy Protein
3.7
kg
Whey Protein
3.2
kg
Caseinate
2.9
kg
Corn Oil
2.0
kg
Tricalcium Phosphate
1.4
kg
Potassium Citrate
1.3
kg
Magnesium Phosphate
952
gm
Lecithin
658
gm
Magnesium chloride
558
gm
Vanilla Flavor
544
gm
Sodium Chloride
272
gm
Carrageenan
227
gm
Choline chloride
218
gm
UTM/TM Premix
165
gm
Potassium Chloride
146
gm
Ascorbic Acid
145
gm
Sodium Citrate
119
gm
Potassium Hydroxide
104
gm
Lutein (5%)
46
gm
WSV Premix
33
gm
Vit DEK Premix
29
gm
Vitamin A
3.7
gm
Potassium Iodide
86
mcg
WSV premix (per g premix): 375 mg/g niacinamide, 242 mg/g calcium pantothenate, 8.4 gm/g folic acid, 62 mg/g thiamine chloride hydrochloride, 48.4 gm/g riboflavin, 59.6 mg/g pyridoxine hydrochloride, 165 mcg/g cyanocobalamin and 7305 mcg/g biotin
Vitamin DEK premix (per g premix): 8130 IU/g vitamin D 3 , 838 IU/g vitamin E, 1.42 mg/g vitamin K 1
UTM/TM premix (per g premix): 45.6 mg/g zinc, 54 mg/g iron, 15.7 manganese, 6.39 mg/g copper, 222 mcg/g selenium, 301 mcg/g chromium and 480 mcg/g molybdenium
The liquid nutritional products of the present invention are manufactured by preparing three slurries that are blended together, heat treated, standardized, packaged and sterilized.
A carbohydrate/mineral slurry is prepared by first heating the required amount of water to a temperature of from about 65° C. to about 71° C. with agitation. With agitation, the required amount of potassium citrate and ultra trace mineral/trace mineral (UTM/TM) premix (distributed by Fortitech, Schnectady, N.Y.) is added. The slurry is greenish yellow in color. Agitation is maintained until the minerals are completely dispersed. With agitation, the required amounts of the following minerals are then added: magnesium chloride, potassium chloride, sodium chloride, sodium citrate, potassium iodide, magnesium phosphate and tricalcium phosphate. Next, the maltodextrin distributed by Grain Processing Corporation, Muscataine, Iowa, U.S.A., sucrose and corn syrup are added to slurry under high agitation, and are allowed to dissolve. The completed carbohydrate/mineral slurry is held with agitation at a temperature from about 65° C. to about 71° C. for not longer than eight hours until it is blended with the other slurries.
A protein in fat slurry (PIF) is prepared by combining and heating the required amounts of high oleic safflower oil and canola oil to a temperature from about 40.5° C. to about 49° C. with agitation. With agitation, the required amounts of free lutein from Kemin Foods of Des Moines, Iowa is added. Agitate for a minimum of 15 minutes. Add the following ingredients are added to the heated oil: lecithin (distributed by Central Soya Company, Fort Wayne, Ind.), vitamin A, and Vitamin D, E, K premix (distributed by Vitamins Inc., Chicago, Ill.). The required amount of carrageenan is dry blended with the required amount of whey protein and add to the agitating lipid mixture and allowed to agitate for a minimum of 10 minutes. The required amount of soy protein is added to the blend slowly to assure proper mixing. The completed oil/protein slurry is held under moderate agitation at a temperature from about 40° C. to about 43° C. for a period of no longer than two hours until it is blended with the other slurries.
A protein in water slurry is prepared by first heating about required amount of water to a temperature of about 40° C. with agitation. The caseinate is added and the slurry is agitated well until the caseinate is completely dispersed. With continued agitation, the slurry is slowly warmed to 60° C. to 65° C. The slurry is held for no longer than twelve hours until it is blended with the other slurries.
The batch is assembled by blending required amount of protein slurry with required amount of the carbohydrate/mineral slurry and allowed to agitate for 10 minutes. With agitation, the required amount of the oil/protein slurry is added and agitate for at least 10 minutes. The pH of the blended batch is adjusted to a pH of 6.66 to 6.75 with 1N potassium hydroxide.
After waiting for a period of not less than one minute nor greater than two hours, the blend slurry is subjected to deaeration, ultra-high-temperature treatment, and homogenization. The blended slurry is heated to a temperature from about 71° C. to about 82° C. and deareated under vacuum. The heated slurry is then emulsified through a single stage homogenizer at 900 to 1100 psig. After emulsification, the slurry is heated from about 99° C. to about 110° C. and then heated to a temperature of about 146° C. for about 5 seconds. The slurry is passed through a flash cooler to reduce the temperature to from about 99° C. to about 110° C. and then through a plate cooler to reduce the temperature to from about 71° C. to about 76° C. The slurry is then homogenized at 3900 to 4100/400 to 600 psig. The slurry is held at about 74° C. to about 80° C. for 16 seconds and then cooled to 1° C. to about 7° C. At this point, samples are taken for microbiological and analytical testing. The mixture is held under agitation.
A water soluble vitamin (WSV) solution is prepared separately and added to the processed blended slurry.
The vitamin solution is prepared by adding the following ingredients to 9.4 kg of water with agitation: WSV premix (distributed by J. B. Laboratories, Holland, Mich.), vitamin C, choline chloride, L-carnitine, taurine, inositiol, folic acid, pyridoxine hydrochloride and cyanocobalamin. The required amount of 45% potassium hydroxide slurry is added to bring the pH to between 7 and 10.
Based on the analytical results of the quality control tests, an appropriate amount of water is added to the batch with agitation to achieve the desired total solids. Additionally, 8.8 kg of vitamin solution is added to the diluted batch under agitation.
The product pH may be adjusted to achieve optimal product stability. The completed product is then placed in suitable containers and subjected to terminal sterilization.
EXAMPLE II
Table 4 presents a bill of materials for manufacturing 1,000 kg of a liquid nutritional product, which provides nutrients to a person with abnormal glucose, containing the brightening agent lutein. A detailed description of its manufacture follows.
TABLE 4
Bill of Materials for Diabetic Liquid Nutritional with Lutein
Ingredient
Quantity per 1,000 kg
Water
QS
Maltodextrin
56
kg
Acidic casein
41.093
kg
Fructose
28
kg
High oleic safflower oil
27.2
kg
Maltitol syrup
16
kg
Maltitol
12.632
kg
Fibersol ® 2(E)
8.421
kg
Caseinate
6.043
kg
Fructooligosaccharide
4.607
kg
Soy polysaccharide
4.3
kg
Canola oil
3.2
kg
Tricalcium phosphate
2.8
kg
Magnesium chloride
2.4
kg
Lecithin
1.6
kg
Sodium citrate
1.18
kg
Potassium citrate
1.146
kg
Sodium hydroxide
1.134
kg
Magnesium phosphate
1.028
kg
m-inositol
914.5
gm
Vitamin C
584
gm
Potassium chloride
530
gm
Choline chloride
472.1
gm
45% Potassium hydroxide
402.5
gm
UTM/TM premix
369.3
gm
Potassium phosphate
333
gm
Carnitine
230.5
gm
Gellan gum
125
gm
Ttaurine
100.1
gm
Vitamin E
99
gm
Lutein Esters (5%)
92
gm
WSV premix
75.4
gm
Vitamin DEK premix
65.34
gm
30% Beta carotene
8.9
gm
Vitamin A
8.04
gm
Pyridoxine hydrochloride
3.7
gm
Chromium chloride
1.22
gm
Folic acid
0.64
gm
Potassium iodide
0.20
gm
Cyanocobalamin
0.013
gm
WSV premix (per g premix): 375 mg/g niacinamide, 242 mg/g calcium pantothenate, 8.4 gm/g folic acid, 62 mg/g thiamine chloride hydrochloride, 48.4 gm/g riboflavin, 59.6 mg/g pyridoxine hydrochloride, 165 mcg/g cyanocobalamin and 7305 mcg/g biotin
Vitamin DEK premix (per g premix): 8130 IU/g vitamin D 3 , 838 IU/g vitamin E, 1.42 mg/g vitamin K 1
UTM/TM premix (per g premix): 45.6 mg/g zinc, 54 mg/g iron, 15.7 manganese, 6.39 mg/g copper, 222 mcg/g selenium, 301 mcg/g chromium and 480 mcg/g molybdenium
The diabetic liquid nutritional products of the present invention are manufactured by preparing four slurries that are blended together, heat treated, standardized, packaged and sterilized.
A carbohydrate/mineral slurry is prepared by first heating about 82 kg of water to a temperature of from about 65° C. to about 71° C. with agitation. With agitation, the required amount of sodium citrate and gellen gum distributed by the Kelco, Division of Merck and Company Incorporated, San Diego, Calif., U.S.A. is added and agitated for 5 minutes. The required amount of the ultra trace mineral/trace mineral (UTM/TM) premix (distributed by Fortitech, Schnectady, N.Y.) is added. The slurry is greenish yellow in color. Agitation is maintained until the minerals are completely dispersed. With agitation, the required amounts of the following minerals are then added: potassium citrate, potassium chloride, chromium chloride, magnesium chloride and potassium iodide. Next, the first maltodextrin distributed by Grain Processing Corporation, Muscataine, Iowa, U.S.A. and fructose are added to slurry under high agitation, and are allowed to dissolve. With agitation, the required amounts of maltitol powder distributed by Roquette America, Inc., Keokuk, Iowa, maltitol syrup distributed by AlGroup Lonza, Fair Lawn, N.J., fructooligosaccharides distributed by Golden Technologies Company, Golden, Colo., U.S.A. and a second maltodextrin distributed by Matsutani Chemical Industry Co., Hyogo, Japan under the product name Fibersol 2(E) are added and agitated well until completely dissolved. The required amount of tricalcium phosphate and magnesium phosphate are added to the slurry under agitation. The completed carbohydrate/mineral slurry is held with agitation at a temperature from about 65° C. to about 71° C. for not longer than twelve hours until it is blended with the other slurries.
A fiber in oil slurry is prepared by combining and heating the required amounts of high oleic safflower oil and canola oil to a temperature from about 40.5° C. to about 49° C. with agitation. With agitation, the required amounts of lutein esters from Cognis of LaGrange, Ill. is added. Agitate for a minimum of 15 minutes. With agitation, the required amounts of the following ingredients are added to the heated oil: lecithin (distributed by Central Soya Company, Fort Wayne, Ind.), Vitamin D, E, K premix (distributed by Vitamins Inc., Chicago, Ill.), vitamin A, vitamin E and beta-carotene. The required amounts of soy polysaccharide distributed by Protein Technology International, St. Louis, Mo. is slowly dispersed into the heated oil. The completed oil/fiber slurry is held under moderate agitation at a temperature from about 55° C. to about 65° C. for a period of no longer than twelve hours until it is blended with the other slurries.
A first protein in water slurry is prepared by heating 293 kg of water to 60° C. to 65° C. With agitation, the required amount of 20% potassium citrate solution is added and held for one minute. The required amount of acid casein is added under high agitation followed immediately by the required amount of 20% sodium hydroxide. The agitation is maintained at high until the casein is dissolved. The slurry is held from about 60° C. to 65° C. with moderate agitation.
A second protein in water slurry is prepared by first heating about 77 kg of water to a temperature of about 40° C. with agitation. The caseinate is added and the slurry is agitated well until the caseinate is completely dispersed. With continued agitation, the slurry is slowly warmed to 60° C. to 65° C. The slurry is held for no longer than twelve hours until it is blended with the other slurries.
The batch is assembled by blending 344 kg of protein slurry one with 84 kg of protein slurry two. With agitation, the 37 kg of the oil/fiber slurry is added. After waiting for at least one minute, 216 kg of the carbohydrate/mineral slurry is added to the blended slurry from the preceding step with agitation and the resultant blended slurry is maintained at a temperature from about 55° C. to about 60° C. The pH of the blended batch is adjusted to a pH of 6.45 to 6.75 with 1N potassium hydroxide.
After waiting for a period of not less than one minute nor greater than two hours, the blend slurry is subjected to deaeration, ultra-high-temperature treatment, and homogenization. The blended slurry is heated to a temperature from about 71° C. to about 82° C. and deaerated under vacuum. The heated slurry is then emulsified through a single stage homogenizer at 900 to 1100 psig. After emulsification, the slurry is heated from about 99° C. to about 110° C. and then heated to a temperature of about 146° C. for about 5 seconds. The slurry is passed through a flash cooler to reduce the temperature to from about 99° C. to about 110° C. and then through a plate cooler to reduce the temperature to from about 71° C. to about 76° C. The slurry is then homogenized at 3900 to 4100/400 to 600 psig. The slurry is held at about 74° C. to about 80° C. for 16 seconds and then cooled to 1° C. to about 7° C. At this point, samples are taken for microbiological and analytical testing. The mixture is held under agitation.
A water soluble vitamin (WSV) solution is prepared separately and added to the processed blended slurry.
The vitamin solution is prepared by adding the following ingredients to 9.4 kg of water with agitation: WSV premix (distributed by J. B. Laboratories, Holland, Mich.), vitamin C, choline chloride, L-carnitine, taurine, inositiol, folic acid, pyridoxine hydrochloride and cyanocobalamin. The required amount of 45% potassium hydroxide slurry is added to bring the pH to between 7 and 10.
Based on the analytical results of the quality control tests, an appropriate amount of water is added to the batch with agitation to achieve desired total solids. Additionally, 8.8 kg of vitamin solution is added to the diluted batch under agitation.
The product pH may be adjusted to achieve optimal product stability. The completed product is then placed in suitable containers and subjected to terminal sterilization.
EXAMPLE III
The following Example illustrates the preparation of a ready-to-feed infant formula containing the brightening agent lutein. The components utilized in the formula are depicted Table 5. The quantities outlined are used to prepare a 7711 kg batch of formula.
TABLE 5
Bill of Materials for ready-to-feed infant formula with Lutein
INGREDIENT
Quantity per 7711 kg
High oleic safflower oil
120.2
kg
Coconut oil
85.7
kg
Soy oil
80.3
kg
Lecithin
2.92
kg
Mono-and diglyceride
2.92
kg
Oil soluble vitamin premix
0.365
kg
β-carotene
0.0137
kg
Carrageenan
1.43
kg
Whey Protein
61.2
kg
Lactose
476.3
kg
Potassium citrate
4.6
kg
Magnesium chloride
0.735
kg
Condensed skim milk
821
kg
Calcium carbonate
3.36
kg
Ferrous sulfate
0.450
kg
Lutein (20%)
11.5
kg
Water Soluble Vitamin Premix
1.11
kg
Trace Minerals/Taurine
Choline chloride
0.600
kg
Adenosine 5′monophosphate
0.113
kg
Guanosine 5′monophosphate-Na2
0.197
kg
Cytidine 5′monophosphate
0.259
kg
Uridine 5′monophosphate-Na2
0.216
kg
Ascorbic acid
1.78
kg
45% KOH
2.36
kg
The first step in the preparation of formulas is the preparation of the oil blend. To an appropriately sized blend tank with agitation and heating soy oil, coconut oil and high oleic safflower oil were added. The mixture is heated to 40.5° C. to 49° C. with agitation. With agitation, the required amounts of free lutein from Roche of Nutley, N.J. is added. Agitate for a minimum of 15 minutes. The lecithin and mono-and diglycerides are added to the blend tank with agitation. The oil soluble vitamin premix is added with 10 agitation. The premix container was rinsed with the oil blend and transferred back to the blend tank to ensure complete delivery of the vitamin premix. The β-carotene is added to the oil blend and the mixture agitated until the components are well dispersed. The β-carotene container is rinsed with the oil blend and the contents returned to the blend tank to ensure complete delivery of the p-carotene solution. Lastly, the carrageenan is added to the oil blend and the mixture is agitated and held at 54.0-60° C. until used.
The carbohydrate, mineral and condensed skim milk (CSM) protein slurry is prepared next. To water heated to 68-73° C. the lactose is added and the mixture agitated until the lactose is well dissolved. Potassium citrate is then added followed by potassium chloride, sodium chloride and magnesium chloride. The condensed skim milk (CSM) and tri-calcium phosphate are then added and the mixture is agitated and held at 54-60° C. until used.
The protein-in-water (PIW) slurry is then prepared. The whey protein is added to water at 54-60° C. under mild agitation. The PIW slurry is held under mild agitation until needed. Also contemplated in this invention is the use of protein-in-fat (PIF) slurries, wherein an appropriate amount of protein is admixed with all or a portion of the oil (fat) component.
The PIW slurry is then added to the prepared oil blend. The required amount of the carbohydrate, mineral and CSM slurry is then added to the oil blend. The pH of the mixture is then determined and if below specification, it is adjusted using KOH to a pH of 6.75 to 6.85. The mixture is then held at 54-60° C. under agitation for at least 15 minutes.
The mixture is then heated to 68-74° C. and deaerated under vacuum. The mixture is then emulsified through a single stage homogenizer at 6.21 to 7.58 MPa. After emulsification, the mixture is heated to 120-122° C. for 10 seconds and then 149-150° C. for 5 seconds. The mixture is then passed through a flash cooler to reduce the temperature to 120-122° C. and then through a plate cooler to reduce the temperature to 71-79° C. The mixture is then passed through a two stage homogenizer at 26.89 to 28.27 MPa and 2.76 to 4.14 MPa. The mixture is held at 73 to 83° C. for 16 seconds and then cooled to 1 to 7° C. At this point, samples are taken for microbiological and analytical testing. The mixture is held under agitation.
A calcium carbonate solution may be prepared for use in adjusting the calcium level of the mixture if outside of specification.
A vitamin stock solution is prepared. To water heated at 37 to 66° C. is added potassium citrate and ferrous sulfate. The vitamin premix is then added and the mixture agitated. The choline chloride is added and then the required amount of this vitamin mixture is added to the batch.
The nucleotide solution is then prepared. The following nucleotides are added to water with mild agitation in the following order: AMP, GMP, CMP, UMP. Agitation is continued for about 10 minutes to dissolve the nucleotides. The nucleotide solution is then added to the batch.
Lastly, an ascorbic acid solution is prepared and added slowly to the batch with agitation for at least 10 minutes. Final dilution with water to meet specified levels of solids and caloric density is completed. The batch is then packaged in suitable containers and sterilized using conventional technology.
EXAMPLE IV
Table 6 presents a bill of materials for manufacturing 454 kg of a vanilla flavored soy-based powder nutritional product containing the brightening agent lutein. A detailed description of its manufacture follows.
TABLE 6
Bill of Materials for Soy-Based Powder
Vanilla Flavored Product with Lutein
Ingredient Name
Quantity per 454 kg
Corn syrup
99.6
kg
Sucrose
122
kg
Soy protein
117.6
kg
Maltodextrin
66.6
kg
High oleic safflower oil
8.2
kg
Canola oil
8.2
kg
Potassium citrate
3.5
kg
Magnesium phosphate
5.0
kg
Vanilla flavor
4.6
kg
Corn oil
4.1
kg
Choline chloride
0.99
kg
Sodium citrate
3.5
kg
UTM/TM premix*
0.7
kg
Ascorbic acid
0.65
kg
Mixed tocopherols
22.7
gm
Vitamin DEK premix**
0.19
kg
Lutein esters (5%)
92
gm
WSV premix{circumflex over ( )}
0.12
kg
Vitamin A palmitate{circumflex over ( )}{circumflex over ( )}
72.6
gm
Potassium iodide
458.5
mg
*The ultratrace mineral/trace mineral (UTM/TM) premix provides 88 gm zinc sulfate (0.194077 lbs.), 114 gm encapsulated ferrous sulfate (0.251651 lbs.), 32 gm manganese sulfate (0.071775 lbs.), 17 gm cupric sulfate (0.037023 lbs.), 1 gm chromium chloride (0.002380 lbs.), 1 gm sodium molybdate (0.002380 lbs), 387 mcg sodium selenate (0.000854 lbs.) to the product.
**The vitamin D, E, K premix provides 27 mcg vitamin D (0.000061 lbs.), 127 gm vitamin E (0.279874 lbs.), and 212 mcg vitamin K (0.000468 lbs) to the product.
{circumflex over ( )}The water soluble vitamin (WSV) premix provides 47 gm niacinamide (0.103155 lbs.), 30 gm d-calcium pantothenate (0.066724 lbs.), 1 gm folic acid (0.002311 lbs.), 8 gm thiamine chloride HCl (0.017030 lbs.), 6 gm riboflavin (0.013309 lbs.), 7 gm pyroxidine HCl (0.016392 lbs.), 20 mcg cyanocobalamin (0.000046 lbs.) and 911 mcg biotin (0.002008 lbs.) to the product.
{circumflex over ( )}{circumflex over ( )}Vitamin A palmitate premix provides 4 gm vitamin A palmitate (0.008608 lbs.) to the product.
The powder nutritional products of the present invention are manufactured by preparing three slurries that are blended together, heat treated, standardized, spray dried and packaged. The process for manufacturing 454 kg of a spray dried powder nutritional product, using the bill of materials from Table 4, is described in detail below.
A 45% to about 55% total solids carbohydrate/mineral slurry is prepared by heating the required amount of water to about 63° C. to about 66° C. The following minerals are added in the order listed, under high agitation: potassium citrate, sodium citrate, and UTM/TM premix (distributed by Fortitech, Inc., Schenectady, N.Y.). The slurry is held under agitation for a minimum of 5 minutes. The remaining minerals are added in the order listed under high agitation: potassium iodide, and magnesium phosphate. The corn syrup is added under high agitation and allowed to dissolve. Next, the maltodextrin (distributed by Grain Processing Corporation, Muscataine, Iowa) is added to slurry under high agitation, and is allowed to dissolve. The sugar (sucrose) is then added under high agitation and allowed to dissolve. The completed carbohydrate/mineral slurry is held with high agitation at a temperature from about 60° C. to about 65° C. for not longer than twelve hours until it is blended with the other slurries.
The oil slurry is prepared by combining and heating the high oleic safflower oil, corn and canola oil. The mixture is heated to 40.5° C. to 49° C. with agitation. With agitation, the required amounts of lutein esters from Quest of Owings Mills, Md. is added. Agitate for a minimum of 15 minutes. The Vitamin D,E,K premix (distributed by Vitamins, Inc., Chicago, Ill.), Vitamin A Palmitate and mixed tocopherols (distributed by Eastman Chemical Company, Kingsport, Tenn.) are then added to the slurry with agitation. The completed oil slurry is held under moderate agitation at a temperature from about 54° C. to about 60° C. for a period of no longer than twelve hours until it was blended with the other slurries.
A 18% to about 22% total solids protein-in-water slurry is prepared by first dispersing the soy protein (distributed by Protein Technologies International, St. Louis, Mo.) in the required amount of water under high agitation. The completed protein-in-water slurry is held under moderate agitation at a temperature from about 63° C. to about 68° C. for a period of no longer than two hours until it is blended with the other slurries.
The protein-in-water and oil slurries are blended together with agitation and the resultant blend is maintained at a temperature from about 60° C. to about 65° C. After waiting for at least five minutes, the carbohydrate/mineral slurry is added to the blend from the preceding step with agitation and the resultant blend is maintained at a temperature from about 60° C. to about 65° C. The total solids of the final blend is about 40% to about 44%. The blend pH is brought up to about 6.8 to about 7.0 with 1N KOH.
After waiting for a period of not less than one minute nor greater than two hours, the blend slurry is subjected to deaeration, HTST treatment, and homogenization. The blended slurry is heated to a temperature from about 68° C. to about 74° C. and deareated under vacuum. The heated slurry is then emulsified at 900 to 1100 psig. After emulsification, the slurry is heated from about 71° C. to about 77° C. for about 16 seconds. The slurry is then homogenized at 3900 to 4100/400 to 600 psig. The slurry is then cooled to about 34° C. to about 45° C. At this point, samples are taken for microbiological and analytical testing. The mixture is held under agitation.
A vitamin solution and a flavor solution are prepared separately and added to the processed blend.
The vitamin solution is prepared by adding the following ingredients to the required amount of water, under agitation: Ascorbic Acid, Water Soluble Vitamin Premix (distributed by Fortitech, Inc., Schenectady, N.Y.) and Choline Chloride. The vitamin solution pH is adjusted to from about 6 to about 10 with 45% KOH. The vitamin slurry is then added to the blended slurry under agitation.
The flavor solution is prepared by adding the natural and artificial flavor to a minimal amount of water with agitation. The flavor slurry is then added to the blended slurry under agitation.
The total solids of the final standardized product is 40%. The product is preheated to 74° C. and homogenized at about 2500/500 psig before spray drying. A pilot scale high pressure nozzle tower spray drier (distributed by NIRO Hudson Inc., Hudson, Wis.) is used to dry the product. Drying conditions are an inlet temperature of 193° C. with an outlet temperature of 103° C. and nozzle #24 is used. The resulting powder is packaged under nitrogen to maximize product stability and flavor.
EXAMPLE V
Table 7 presents a bill of materials for manufacturing 771 kg of a pediatric enteral nutritional containing the brightening agent lutein of the instant invention. A detailed description of its manufacture follows.
TABLE 7
Bill of materials for vanilla pediatric nutritional
Ingredient
Quantity per 771 kg
Stock PIF Slurry
High oleic safflower oil
40.7
kg
Soy oil
24.4
kg
MCT oil
16.3
kg
Lecithin
840.2
g
Monoglycerides
840.2
g
Carrageenan
508.9
g
Caseinate
32.8
kg
Stock OSV blend
DEK premix
83.3
g
Vitamin A
7.1
g
Lutein esters (5%)
92
g
Stock PIW slurry
Water
530
kg
Caseinate
11.3
kg
Whey protein
11.9
kg
Stock MIN slurry
Water
18
kg
Cellulose gum
1696
g
Magnesium chloride
2.7
kg
Potassium chloride
1.0
kg
Potassium citrate
2.7
kg
Potassium iodide
0.25
g
Dipotassium phosphate
1.45
kg
Final blend
PIW slurry
251
kg
PIF slurry
53
kg
MIN slurry
12.6
kg
Sodium chloride
127.4
g
Sucrose
77.6
kg
Tricalcium phosphate
2.5
kg
Water
167
kg
Stock WSV solution
Water
31.7
kg
Potassium citrate
3.74
g
UTM/TM premix
172.2
g
WSV remix
134.1
g
m-inositol
176.7
g
Ttaurine
145.5
g
L-carnitine
34.92
g
Choline chloride
638.7
g
Stock ascorbic acid solution
Water
18.6
kg
Ascorbic acid
550.0
g
45% KOH
341
g
Stock vanilla solution
Water
38.5
kg
Vanilla flavor
4.3
kg
DEK premix: (per gm premix) 12,100 IU vitamin D 3 , 523 IU vitamin E, 0.962 mg vitamin K 1
UTM/TM premix: (per gm premix) 132 mg zinc, 147 mg iron, 10.8 mg manganese, 12.5 mg copper, 0.328 mg selenium, 0.284 mg molybdenum
WSV premix: (per gm premix) 375 mg niacinamide, 242 mg d-calcium pantothenate, 8.4 mg folic acid, 62 mg thiamine chloride hydrochloride, 48.4 mg riboflavin, 59.6 mg pyridoxine hydrochloride, 165.5 mcg cyanocobalamin, 7305 mcg biotin
The stock oil soluble vitamin blend (OSV blend) is prepared by weighing out the specified amount of DEK premix into a screw cap, light protected container large enough to hold 54 g of oil soluble vitamins. Using a plastic pipette, the required amount of vitamin A is added to the DEK aliquot. The container is flushed with nitrogen prior to applying the lid.
The stock protein in fat slurry (PIF) was prepared by adding the required amounts of high oleic safflower oil, soy oil and MCT oil to the blend tank. The mixture is heated to 40.5° C. to 49° C. with agitation. With agitation, the required amounts of lutein esters from American River Nutrition of Hadley, Mass. is added. Agitate for a minimum of 15 minutes. The emulsifiers, lecithin (distributed by Central Soya of Decatur, Ind.) and monoglycerides (distributed by Quest of Owings Mills, Md.), are added and mixed well to dissolve. All of the OSV blend is then added. The containers are rinsed out 4 to 5 times with the oil blend to assure complete transfer of the vitamins. The carrageenan (distributed by FMC of Rockland, Me.) and the caseinate are added. The slurry is mixed well to disperse the protein. The PIF slurry is held up to six hours at 60-65° C. under moderate agitation until used.
The stock protein in water slurry (PIW) is prepared by adding the required amount of water to a blend tank. The water is held under moderate agitation and brought up to 76-82° C. The required amount of caseinate is added to the water under high agitation and mixed on high until the protein is fully dispersed. The protein slurry is allowed to cool to 54-60° C. before proceeding. Once cooled the required amount of whey protein is added and mixed well until fully dispersed/dissolved. The PIW slurry is held up to two hours at 54-60° C. until used.
The stock mineral solution (MIN) is prepared by adding the required amount of water to a blend tank and heated to 60-68° C. The cellulose gum blend (distributed by FMC of Newark, Del.) is added to the water and held under moderate agitation for a minimum of five minutes before proceeding. The mineral salts magnesium chloride, potassium chloride, potassium citrate, potassium iodide and dipotassium phosphate are added one at a time with mixing between each addition to ensure the minerals dissolved. The completed MIN solution is held at 54-65° C. under low to moderate agitation until used.
The final blend is prepared by adding the specified amount of PIW slurry to a blend tank and heated under agitation to 54-60° C. The specified amount of PIF slurry is added to the tank and mixed well. The specified amount of MIN solution is added to the blend and mixed well. The specified amount of sodium chloride is added to the blend and mixed well. The specified amount of sucrose is added to the blend and mixed well to dissolve. The tricalcium phosphate is added to the blend and mixed well to disperse. The specified amount of additional water is added to the blend and mixed well. The completed final blend is held under continuous agitation at 54-60° C. If necessary, the pH is adjusted to 6.45-6.8 with 1N KOH.
After waiting for a period of not less than one minute nor greater than two hours, the blend slurry is subjected to deaeration, ultra-high-temperature treatment, and homogenization. The blended slurry is heated to a temperature from about 68° C. to about 74° C. and deaerated under vacuum. The heated slurry is then emulsified at 900 to 1100 psig. After emulsification, the slurry is heated from about 120° C. to about 122° C. and then heated to a temperature of about 149° C. to about 150° C. The slurry is passed through a flash cooler to reduce the temperature to from about 120° C. to about 122° C. and then through a plate cooler to reduce the temperature to from about 74° C. to about 79° C. The slurry is then homogenized at 3900 to 4100/400 to 600 psig. The slurry is held at about 74° C. to about 85° C. for 16 seconds and then cooled to 1° C. to about 6° C. At this point, samples are taken for microbiological and analytical testing. The mixture is held under agitation.
Standardization proceeds as follows. The stock vitamin solution (WSV) is prepared by heating the specified amount of water to 48-60° C. in a blend tank. Potassium citrate, UTM/TM premix (distributed by Fortitech of Schenectady, N.Y.), WSV premix, m-inositol, taurine, L-carnitine and choline chloride are each added to the solution in the order listed and allowed to mix well to dissolve or disperse each ingredient. 14.2 kg of the vitamin solution is added to the processed mix tank.
The stock vanilla solution is prepared by adding the specified amount of water to a blend tank. The specified amount of vanilla (distributed by Givaudan Roure of Cincinnati, Ohio) is added to the water and mixed well. 18.5 kg of vanilla solution is added to the processed mix tank and mixed well.
The stock ascorbic acid solution is prepared by adding the required amount of water to a blend tank. The specified amount of ascorbic acid is added and mixed well to dissolve. The specified amount of 45% KOH is added and mixed well. 8.4 kg of ascorbic acid solution is added to the mix tank and mixed well.
The final mix is diluted to the final total solids by adding 92.5 kg of water and mixed well. Product is filed into suitable containers prior to terminal (retort) sterilization.
EXAMPLE VI
Nutritional formulas manufactured as described in Example I were analyzed for color. Table 8 lists the Hunter color values of various flavore/colored nutritionals that contain various levels of lutein compounds. Color photos of corresponding samples are attached as FIGS. 2-5 to illustrate the brightening effect of lutein compounds.
TABLE 8
Hunter Color Values
Lutein content
Sample
(mg/8 fl. oz)
L
a
b
9C (Unflavored)
1.026
66.6
0.7
22.2
9-1 (Unflavored)
0.548
67.7
0.9
19.3
9-2 (Unflavored)
0.622
66.8
0.8
20.4
9-3 (Unflavored)
0.724
66.9
0.8
21.4
9-4 (Unflavored)
0.604
66.8
0.5
21.1
9-5 (Unflavored)
0.409
66.6
0.7
20.0
E1 (Vanilla Control)
None added
67.8
1.8
15.2
VE2 (Vanilla)
0.768
64.8
1.1
20.9
BE2 (Butter Pecan)
0.812
63.2
1.0
20.2
CE2 (Coffee)
0.824
56.5
0.6
17.2
EE2 (Eggnog)
0.722
63.2
1.0
20.6
SE2 (Strawberry)
0.827
56.5
14.4
14.2
EC1 (Chocolate Control)
None added
32.7
3.8
5.4
EC2 (Chocolate)
1.121
32.7
3.3
7.1
EC3 (Chocolate)
1.106
32.6
3.3
7.0
EC4 (Chocolate)
1.416
32.2
3.2
6.3
“L” value measures lightness (100.00) to darkness (0.00).
“a” value measures red when the result is a positive number, gray when 0.00 and green when the result is negative.
“b” value measures yellow when the result is a positive number, gray when 0.00 and blue when the result is negative.
The Hunter values in Table 8 describe the changes occurring in the “L”, “a” and “b” axes of the three dimensional graph. When adding a colored ingredient to a nutritional base that already has a color, the expectation is that the final color will be the sum of the chromophores. For example, adding a yellow/orange compound to a brownish red base would result in a darker brown base or adding a yellow/orange compound to a white base would result in a yellow/orange base. The inventors discovered that in addition to the yellow/orange nature of the lutein compounds not dominating the final product color, the typical brown base colors of the nutritionals were diminished thereby making the final nutritional look brighter.
This is demonstrated in Table 8 by the decrease in the “a” values. The products were less red after the addition of the lutein compounds. The shift from red is further illustrated in the strawberry samples of FIG. 4 . The artificial pink/red of the control is changed, with the addition of the brightening agent, to the softer more natural strawberry color. In addition to a decrease in the red values, there was an increase in the “b” values, thereby moving the final color away from the gray hues.
The light/dark values (L) of the same flavors did not significantly change with the addition of lutein. The variability of the “L” values between flavors typically correlated with the overall color of the specific flavor. For, example the nutritionals with the non-white base colors, such as chocolate, coffee and strawberry, had lower “L” values. The light base samples, such as unflavored, vanilla, butter pecan and eggnog, had higher “L” values. Further, the unflavored sample's “L” values did not shift significantly with the addition of 0.4 mg or 1.0 mg/8 fl.oz. of lutein. Importantly, while the “L” value of the light mix samples did not change significantly, the corresponding samples in FIGS. 2 and 3 which contain lutein look brighter to the eye.
The Hunter values analytically describe the specific changes occurring in the three axes. However, it is the combination of these changes that the eye detects. The result is a more appealing, brighter nutritional as illustrated in FIGS. 2-5. | In accordance with the present invention, it has been discovered that the addition of lutein compounds to thermally processed nutritionals brightens the nutritional resulting in a more appealing color. Thermally processed liquid and powder nutritionals typically present brown and gray hues in the final color, which negatively impact the overall appeal of the nutritional. The inventors have discovered that the lutein compounds eliminate the gray and brown hues without imparting the relatively strong yellow color typically associated with lutein compounds. Additionally, the nutritionals possess long term color stability. | 0 |
FIELD OF THE INVENTION
The invention relates to a method and an apparatus for lapping and polishing large optical surfaces such as telescope mirrors, grazing incidence optical components for X-ray telescopes and the like.
Background of the Invention
Lapping and polishing by conventional techniques of relatively large optical members such as are required for astronomical observations are very time-consuming because it is extremely difficult to achieve the desired shape with the required accuracy of fractions of the wavelength of light, typically about 10-50 nm RMS, over the total surface to be worked.
To shorten the work time, an apparatus has already been proposed wherein a tool covering the entire surface of the workpiece to be processed is provided in the shape of a flexible membrane. Moreover, the tool, on whose lower side the polishing elements are fastened, oscillates tangentially over the workpiece under a series of loading units. These loading units are stationary relative to the workpiece and produce a pressure distribution calculated from the deviations of the workpiece from the desired shape.
If desired, these loading units can be moved together with their support laterally relative to the membrane by an amount which is small in comparison to the amplitude of the membrane movement. In this way, the loading units are prevented from impressing the workpiece which, for example, could occur if the stiffness of the membrane is selected as being relatively small.
This apparatus is disclosed in U.S. Pat. No. 4,606,151 which is incorporated by reference herein. With this apparatus it is difficult, nevertheless, to work on very large members such as telescope mirrors with a diameter of four meters or larger because the correspondingly large tool is then difficult to handle. Problems arise, among others, with respect to the metering of the polishing liquid which must always be supplied very uniformly as well as with the preparation of the tool, that is, applying the tool to the workpiece and the pressing of the tool to its proper shape between subsequent working cycles. In addition, large local pressure differences on the rearward side of the tool can cause running of the polishing means carrier, so that the tool deforms rather quickly. This leads to a reduction of the useful dynamics of the polishing process.
Furthermore, with the known apparatus, it is not possible without additional effort to work on grazing incidence optical devices such as conical shells of Wolter telescopes for the X-ray astronomy.
Another polishing apparatus which is similar to that discussed above is disclosed in U.S. Pat. No. 2,399,924. This apparatus also uses a flexible membrane as a tool which extends over the entire surface to be worked upon. This membrane is loaded according to a pressure distribution adapted to a predetermined material removal. With this apparatus, the workpiece to be worked upon is rotated at the same time.
However, with this kind of apparatus, it is only possible to polish away rotationally-symmetrical deviations from the desired shape of the workpiece. Furthermore, it is not possible to eliminate short periodic deviations because the pressure distribution on the rearward side of the tool shifts with the polishing movements relative to the workpiece, since the pressure distribution is produced by weights which rest on the membrane and move with the membrane over the surface to be worked upon.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a method and an apparatus by means of which the above-described disadvantages will be avoided. The method is intended to provide for very short work times and, with respect to the deviations in shape to be eliminated, should be universally applicable to the greatest possible extent.
The method according to the invention is for lapping and polishing a surface of an optical workpiece wherein the contour of the surface to be lapped or polished is first measured and the lapping or polishing process is controlled in correspondence to the deviations of the actual surface contour from a predetermined desired shape. The method of the invention includes the steps of: laying down upon the surface at least one lapping and polishing tool having the form of a strip-like flexible membrane covering only a portion of the surface; applying a plurality of pressure forces to the membrane at a plurality of locations on the side of the membrane facing away from the surface to generate a pressure force distribution corresponding to the deviations, the pressure forces having respective magnitudes which vary as a function of time; imparting an oscillatory movement to the membrane in a predetermined first direction transverse to the pressure forces so as to cause the membrane to move across the surface and to remove material from the surface; moving the workpiece and the tool relative to each other in a predetermined second direction; and, controlling the respective magnitudes of the pressure forces as a function of time in dependence upon the instantaneous relative position between the workpiece and the tool in the second direction of movement in order to correspond to the deviations of that portion of the surface contour covered by the membrane.
The above-described method of the invention is carried out by means of the apparatus of the invention. According to a feature of the apparatus of the invention, a drive introduces a relative movement between the tool and the workpiece in a second direction. The apparatus also includes a position measuring system as well as a controller connected to the position measuring system and to the loading units so that the force applied by the loading units can be varied with reference to this second direction of movement in dependence upon the instantaneous position of the workpiece or the tool.
For rotationally-symmetrical workpieces, it is useful when the movement in the second direction is a rotary movement. The time dependent pressure force distribution is then controlled in dependence upon the rotation angle ρ between the workpiece and the tool. This angle can be determined by an appropriate angle encoder.
However, it is also possible, for example, to mount the workpiece on a carriage which moves linearly and to control the pressure distribution corresponding to the measured values of a length-measuring system connected with the carriage.
One advantage of the method according to the invention is that the strip-shaped tool, because of its relatively smaller size, can be more easily made and handled than a tool covering the entire workpiece.
Further, the differences of the working pressures between individual points on the rearward side of the tool averaged in time, are much smaller than in the case of complete covering of the workpiece. The extent to which the material of the polishing pads can run off is therefore correspondingly smaller. Because of the foregoing, fewer pressing operations are necessary which interrupt the actual polishing process.
Because of the geometry of the tool, the feed of the polishing fluid also can be achieved more easily.
Finally, it has been established that the time required for the actual polishing operation is not increased to the same extent as the surface of the working tool is decreased. The loss of time caused by the partial covering is, instead, compensated for by a faster convergence of the individual, sequentially performed processing cycles, which comprise a plurality of polishing operations, and intermediate measuring operations, wherein the progress of the processing is controlled and the pressure distribution calculated from the deviations is again adjusted. This improved convergence performance can be explained by a smaller embossment of the imperfections of the tool itself on the surface to be worked upon as a result of the averaging of this effect because of the larger degree of relative movement between the tool and the workpiece.
An additional shortening of the processing time can be achieved by utilizing several strip-shaped tools simultaneously to work on the part to be polished.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described with reference to the drawings wherein:
FIG. 1 is a schematic plan view of an apparatus suitable for lapping and polishing astronomical telescopes;
FIG. 2 is a side-elevation view, partially in section of the apparatus of FIG. 1;
FIG. 3 is a perspective view showing the application of the method according to the invention to a grazing incidence optical component;
FIG. 4 is a schematic representation of another embodiment of the strip-shaped tool utilized in the apparatus of the invention shown in FIGS. 1 and 2 and in FIG. 3;
FIG. 5 is a perspective view of a non-rotationally symmetrical workpiece to be processed in accordance with the method of the invention;
FIG. 6 is a plan view of an apparatus suitable for lapping and polishing the workpiece of FIG. 5 taken along line VI--VI of FIG. 7;
FIG. 7 is a side-elevation view, partially in section, taken along line VII--VII of FIG. 6;
FIG. 8 is a schematic representation of an alternative embodiment of the tools used in the embodiment of FIGS. 1 and 2 and in the embodiment of FIGS. 6 and 7;
FIG. 9 is a diagram showing the pressure distribution in the direction of movement (y) required for eliminating the residual defects ΔZ from the surface of the workpiece 31 of FIG. 8; and,
FIG. 10 graphically shows the time dependency of the pressure of one of the loading units 37 of FIG. 8.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The polishing apparatus shown in FIGS. 1 and 2 has a rotatably journaled seat 2 for accommodating the workpiece 1 thereon. The workpiece is, for instance, the main mirror of a telescope for astronomical observations having a diameter of eight meters. The seat 2 is driven by a motor 3 having a shaft on which an encoder 4 is mounted for detecting the angle of rotation.
The polishing tool utilized for working upon the surface of the workpiece comprises a strip-shaped flexible membrane 5 made of aluminum and having a length of five meters and a width of about one meter. Polishing pads 9 made of pitch are applied to the lower side of the membrane. In describing the tool 5 as being a membrane, it should be noted that the membrane for the measurements given above can have a thickness of 1 cm or more throughout. A drive 6 imparts an oscillatory movement to this strip-shaped tool 5 in a radial direction as indicated by the arrow R. The guides along which this movement is effected are not shown in the drawing.
A loading device 7 rests on the rearward side of the membrane 5 and comprises a plurality of loading units radially arranged in a row one behind the other. These loading units are electromagnetically or hydraulically controlled actuators of the kind described, for example, in U.S. Pat. No. 4,606,151 referred to above and incorporated herein by reference. The loading device 7 remains stationary relative to the workpiece 1 and does not take part in the oscillatory movement of the membrane 5.
The individual loading units of the loading device 7 are individually charged with a force by means of a control unit 8 calculated from the measured deviations of the surface of the mirror 1 from the desired shape. The pressure force applied by each individual actuator of the device 7 thus can be varied in time in dependence upon the azimuthal angle which is reported by the encoder 4 to the control instrument 8. Correspondingly, non rotationally-symmetrical defects will also be attacked during the polishing or lapping process. The prerequisite for this process is that the azimuthal pattern of the defects on the mirror surface is determined and stored in the memory of the computer connected to the control unit 8.
It is entirely possible to work on the mirror simultaneously with several tools as indicated in FIG. 1 by the tool 15 represented in phantom outline.
FIG. 3 is a perspective representation to show how the method of the invention can be adapted to work upon a grazing incidence optical workpiece. Here reference numeral 11 indicates a conical shell of a Wolter telescope having an inner surface which must be polished. For polishing, a strip-shaped tool 12 is utilized which oscillates along the generating line of the cone 11. This oscillatory movement is represented by the arrow M in FIG. 3. The conical shell 11 itself rotates about its longitudinal axis.
Inside the conical shell 11, a series of actuators 13 rest on the rearward side of membrane 12 each applying individually an adjustable and time varying force in dependence upon the rotation angle ρ of the shell 11. The actuators 13 do not take part in the oscillatory movement of the membrane 12; instead, they are mounted to remain stationary with respect to the direction of the generating line of the cone or perform an independent movement with smaller amplitude and frequency compared to the movement of the membrane 12 in a direction perpendicular to the direction of membrane movement.
In both embodiments of the invention according to FIGS. (1, 2) and FIG. 3, the loading device 7 or 13, respectively, has only one row of actuators arranged on the rearward side of each of the strip-shaped members 5 and 12. This is not, however, absolutely required. It is quite advantageous to control simultaneously several rows of actuators, arranged one behind the other, and loading one membrane. With the total surface of the tool being predetermined, this allows also attacking deviations of the workpiece surface having a relatively high spatial frequency. This case is illustrated in FIG. 4. The tool 16 shown there has 45 actuators, arranged in three rows, each with 15 individual units 16a loading on the rearward side of the movable membrane.
It also is not required that the tool or the surface to be worked upon be moved during its rotation through a closed circle. In particular, for processing workpieces which represent segments or sections of a complete mirror, a movement should be provided which reverses itself at the edges of the workpiece, that is, a back and forth or reciprocating rotational movement wherein also the time dependent signal controlling the pressure force distribution pattern reverses itself.
When dealing with the above-described kinds of segments which, like the part 21 of the complete mirror 20 shown in FIG. 5, either have rectangular boundaries or have a spacing to the center of the circle which is relatively large, then it is useful to provide a linear movement instead of a rotational movement between workpiece and tool.
This case will be explained below with reference to FIGS. 6 and 7. Here, the workpiece 21 to be lapped is placed on a carriage 22 guided for linear movement with respect to the axis (x). This carriage 22 is set into a reciprocating movement by means of drives 23a and 23b which act upon threaded spindles. The instantaneous position of the carriage along axis (x) is established by a reading head 24 of a scale 34 attached to the carriage.
A processing tool in the form of a strip-shaped membrane 25 lies upon the workpiece 21. The membrane 25 is set into an oscillatory movement perpendicular to the direction of the movement of the carriage by means of two drives 26a and 26b. As in the embodiment of FIGS. 1 and 2, also here a loading device 27 comprising a plurality of closely packed actuators with adjustable force are supported on the rearward side of the membrane 25. The actuators are, for example, arranged in 3 rows with each row containing 12 units.
The pressure force P i of the individual actuators 27 is controlled by a control unit 28 in dependence upon the position of the carriage 22 in the x-direction, which the reading head 24 of the length measuring system reports to the control unit 28. For this purpose, values of the pressure P i are assigned to each position which are determined beforehand from the deviation pattern of the mirror surface in the x-direction and are stored in the memory of a computer attached to the control unit 28.
In the above-described embodiments, the actuators for producing the pressure force are in each case stationary, while the actual processing tool, the strip-shaped membrane (5 or 25) oscillates between the actuators and the surface of the workpiece.
However, for structural reasons, it can be useful if the membrane 35 and actuators 37 shown in FIG. 8 are united to define a tool 39 and conjointly move in the longitudinal direction (y) of the strip. In this case, the time dependent pressure force distribution pattern of the actuators should, however, be controlled not only according to the pattern of deviations ΔZ of the workpiece surface 31 extending in one coordinate (linear or rotational), but also the deviation pattern extending in the direction of movement (y) of the tool must be taken into consideration; that is, the pressure of the actuators must be controlled at each time point in dependence upon the position of each individual actuator with respect to both coordinates on the surface of the workpiece. Only in this way can the condition be obtained that the pressure distribution P(y), remains constant during the course of the processing operation with respect to this direction of movement of the tool relative to the workpiece. The pressure distribution P(y) is calculated in correspondence to the deviations of the workpiece 31 from the desired shape and is illustrated by way of example in FIG. 9.
Onto the pressure function P(x) or P(α) with which the actuators 37 are loaded in correspondence to the movement of the workpiece 31 in one direction as illustrated in FIGS. (1, 2) and (5, 6), also must be superimposed a second pressure function corresponding to the variation of the processing deviations within the amplitude (A) of the movement of each actuator in the y-direction.
Should this last-mentioned oscillatory movement of the workpiece 39 occur sufficiently fast in comparison to the workpiece 31, a time dependent representation as shown, for example, in FIG. 10 is obtained for the pressure of the actuator 37a of FIG. 8.
It is understood that the foregoing description is that of the preferred embodiments of the invention and that various changes and modifications may be made thereto without departing from the spirit and scope of the invention as defined in the appended claims. | The workpiece which is moved relative to the tool is processed by a tool configured in the form of a strip-shaped flexible membrane. On the rearward side of the membrane, loading units are arranged with the force of each unit being individually controlled. The pressure distribution exerted by the loading units on the workpiece is varied with time in dependence upon the position of the workpiece. With the method, large optical components such as telescope mirrors and grazing-incidence optical elements for x-ray telescopes can be polished more quickly than by the heretofore known methods. Also non-rotationally symmetrical defects of the surface can be eliminated. An apparatus for carrying out the method of the invention is also disclosed. | 1 |
This application is a continuation of prior U.S. application Ser. No. 189,718 filing date May 3, 1988 now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a thermosetting resin composition having excellent heat resistance and high-temperature mechanical properties.
2. Description of the Prior Art
In order to seal electronic components such as diodes, transisters and integrated circuits, resin seal making use of a thermosetting resin has been used widely to date because the resin seal has been economically advantageous over hermetic seal making use of a glass, metal or ceramics. As the resin sealing materials, epoxy resins suitable for use in low-pressure molding may generally be used from the viewpoints of reliability and cost. The epoxy moding materials useful for the low-pressure molding are prepared by mixing a novolak phenol resin as a hardener, 1,4-diazabicyclo[2,2,2]-octane or imidazol as a hardening accelerator, silica powder or alumina powder as a filler, etc. with a novolak cresol- or novolak phenol-epoxy resin and then heating and kneading them. These molding material are separately preheated as tablets. Thereafter, an insert is set in a mold, and its corresponding insoluble and infusible molded articles for electronic components are made from the tablets in accordance with the transfer molding, cast molding or dip molding.
These molding materials are however accompanied by the drawbacks that they are insufficient in heat resistance as the densification of electronic components advances and are hence poor in reliability.
SUMMARY OF THE INVENTION
An object of this invention is to provide a molding material of a heat-resistant resin having excellent heat resistance and mechanical properties.
The above object of this invention has now been accomplished by the provision of a thermosetting resin composition comprising:
100 parts by weight of a polyaminobismaleimide resin composed of a bismaleimide compound represented by the following general formula (I): ##STR1## wherein R 1 means a divalent group of ##STR2## and X denotes a direct bond or a group selected from divalent hydrocarbon group having 1-10 carbon atoms, hexafluorinated isopropylidene group, carbonyl group, thio group, sulfinyl group, sulfonyl group and oxo group, and a diamine compound represented by the following general formula (II): ##STR3## wherein R 2 means a divalent group of ##STR4## and X denotes a direct bond or a group selected from divalent hydrocarbon group having 1-10 carbon atoms, hexafluorinated isopropylidene group, carbonyl group, thio group, sulfinyl group, sulfonyl group and oxo group; and
30-800 parts by weight of a powdery inorganic filler.
The thermosetting resin composition of this invention has excellent heat resistance as well as superb mechanical properties at high temperature not to mention room temperature, and is expected to find wide-spread commercial utility in electric and electronic components such as sealing materials, sockets and connectors and other applications. It therefore has significant industrial utility.
DETAILED DESCRIPTION OF THE INVENTION
Illustrative examples of the bismaleimide compound (I), which is useful as one of the components of the polyaminobismaleimide resin in the present invention, include:
1,3-bis(3-maleimidophenoxy)benzene;
bis[4-(3-maleimidophenoxy)phenyl]methane;
1,1-bis[4-(3-maleimidophenoxy)phenyl]ethane;
1,2-bis[4-(3-maleimidophenoxy)phenyl]ethane;
2,2-bis[4-(3-maleimidophenoxy)phenyl]propane;
2,2-bis[4-(3-maleimidophenoxy)phenyl]butane;
2,2-bis[4-(3-maleimidophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane;
4.4'-bis(3-maleimidophenoxy)biphenyl;
bis[4-(3-maleimidophenoxy)phenyl]ketone;
bis[4-(3-maleimidophenoxy)phenyl]sulfide;
bis[4-(3-maleimidophenoxy)phenyl]sulfoxide;
bis[4-(3-maleimidophenoxy)phenyl]sulfone; and
bis[4-(3-maleimidophenoxy)phenyl]ether.
They may be used either singly or in combination. These bismaleimide compounds may be prepared easily by subjecting their corresponding diamine compounds and maleic anhydride to condensation and dehydration.
Illustrative specific examples of the other component, the diamine compound (II), include:
1,3-bis(3-aminophenoxy)benzene;
bis[4-(3-aminophenoxy)phenyl]methane;
1,1-bis[4-(3aminophenoxy)phenyl]ethane;
1,2-bis[4-(3-aminophenoxy)phenyl]ethane;
2,2-bis[4-(3-aminophenoxy)phenyl]propane;
2,2-bis[4-(3-aminophenoxy)phenyl]butane;
2.2-bis[4-(3-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane;
4.4'-bis(3-aminophenoxy)biphenyl;
bis[4-(3-aminophenoxy)phenyl]ketone;
bis[4-(3-aminophenoxy)phenyl]sulfide;
bis[4-(3-aminophenoxy)phenyl]sulfoxide;
bis[4-(3-aminophenoxy)phenyl]sulfone; and
bis[4-(3-aminophenoxy)phenyl]ether.
They may also be used either singly or in combination.
As polyaminobismaleimide resins composed of the above-exemplified bismaleimide compounds and diamine compounds, may be mentioned (1) those obtained by simply mixing them and (2) those obtained by subjecting them to a heat treatment and then grinding the resultant mixture into pellets or powder. As heating conditions for the heat treatment, it is preferable to choose conditions in which they are partly hardened to the stage of prepolymer. In general, it is suitable to heat them at 70°-220° C. for 5-240 minutes, preferably at 80°-200° C. for 10-180 minutes. Also included are (3) those obtained by dissolving them in an organic solvent, pouring the resultant solution into a bad solvent, collecting the resultant crystals by filtration and then drying the thus-collected crystals into pellets or powder or by dissolving them in an organic solvent, hardening them partly to the stage of prepolymers, discharging the resultant mixture into a bad solvent, collecting the resultant crystals by filtration and then drying the thus-collected crystals into pellets or powder. As exemplary organic solvents usable upon formation of the resins (3), may be mentioned halogenated hydrocarbons such as methylene chloride, dichloroethane and trichloroethylene; ketones such as acetone, methyl ethyl ketone, cyclohexanone and diisopropyl ketone; ethers such as tetrahydrofuran, dioxane and methylcellosolve; aromatic compounds such as benzene, toluene and chlorobenzene; and aprotic polor solvents such as acetonitrile, N,N-dimethylformamide, N,N-dimethylacetoamide, dimethyl sulfoxide, N-methyl-2-pyrrolidone and 1,3-dimethyl-2-imidazolidinone.
Regarding the proportions of each bismaleimide compound and its corresponding diamine compound, the diamine compound may be used in an amount of 0.1-1.2 moles, preferably 0.2-0.8 moles, per mole of the bismaleimide compound. If the diamine compound is used in a smaller proportion, it is difficult to obtain a resin having good impact resistance and flexibility upon hardening. On the other hand, any unduly high proportions give deleterious effects to the heat resistance of a hardened resin to be obtained.
A variety of powdery inorganic fillers may be used in the present invention, including silica powder, alumina powder, silicon carbide powder, silicon nitride powder, boron nitride powder, zircon powder, calcium silicate powder and calcium carbonate powder by way of example. The use of silica powder, alumina powder and silicon carbide powder is particularly preferred. The particle size distribution of the powdery inorganic filler used in the present invention may desirably range from 1 to 50 μm.
As illustrative examples of the silica powder useful in the practice of this invention, may be mentioned those obtained by grinding high-purity quartz in a ball mill or the like into particles having a predetermined size distribution, by grinding amorphous quartz glass, which has been obtained by completely melting high-purity quartz at a high temperature of 1900° C., in a ball mill or the like into particles having a predetermined size distribution and by mixing both particles with each other. From the standpoint of properties, the particle size distribution in a range of 1-50 μm is particularly preferred.
The alumina powders usable in the practice of this invention may include, for example, those obtained by igniting and fusing an aluminum oxide ore and the grinding the thus-fused ore in a ball mill or the like into particles having a predetermined size distribution and by hydrolyzing anhydrous aluminum chloxide with an oxygen-hydrogen flame in a gaseous phase. From the standpoint of properties, the particle size distribution in a range of 1-50 μm is particularly preferred.
The silicon carbide powder usable in the practice of this invention may include that obtained by igniting carbon powder and clay powder as raw materials in an electric resistance furnace and then grinding the thus-ignited raw materials in a ball mill or the like into particles having a predetermined size distribution. From the standpoint of properties, the particle size distribution in a range of 1-50 μm is particularly preferred.
In the present invention, the powdery inorganic filler may be used in a proportion of 30-800 parts by weight, preferably 50-400 parts by weight, per 100 parts by weight of the above-mentioned polyaminobismaleimide resin composed of the bismaleimide compound and diamine compound. Any proportions smaller than 30 parts by weight cannot bring about effects imparting heat resistant, mechanical properties and moldability or formability, which constitute the characteristic features of the present invention. If, on the contrary, the powdery inorganic filler is used in a proportion greater than 800 parts by weight, the resultant composition is only increased in its quantity and shows poor fluidity upon forming or molding. It is hence unsuitable to use such a composition in practice.
Although the thermosetting resin composition according to the present invention may be prepared by a method known generally in the art, the following methods are particularly preferred:
(1) After mixing the polyaminobismaleimide resin in the form of powder and powdery inorganic filler in a mortar, Henschel mixer, drum blender, tumbler mixer, ball mill or similar device, and kneading the resultant mixture by a melting and mixing machine or heated roll as needed, the mixture is formed into pellets or powder.
(2) The polyaminobismaleimide resin powder is dissolved or suspended in an organic solvent in advance. The powdery inorganic filler is impregnated with the resultant solution or suspension. After removing the solvent in a hot-air oven, the resultant mixture is formed into pellets or powder. Since the temperature and time required for the kneading vary depending on the properties of the polyaminobismaleimide resin employed, they may be adjusted suitably so that the softening temperature and gelling time of the resultant composition fall within a range of 70°-180° C. and a range 30-180 seconds at 200° C.
The thermosetting resin composition of this invention may be added with a polymerization catalyst as needed. No particular limitation is imposed on the proportion of the catalyst. It is however preferable to use the catalyst within a range of 0.001-10 wt. %, preferably 0.1-5 wt. %, based on the total weight of the resultant polymer. As the polymerization catalyst, a known free radical catalyst is effective such as benzoyl peroxide, t-butylhydroperoxide, dicumyl peroxide, azobisisobutyronitrile or azobiscyclohexanecarbonitrile. Two or more of these polymerization catalysts may be used suitably in combination.
Further, it is also possible to use a releasing agent such as a higher fatty acid, metal salt thereof or ester wax, a colorant such as carbon black and/or a coupling agent such as an epoxysilane, aminosilane, vinylsilane, alkylsilane, organic titanate or aluminum alcoholate for the composition of the present invention, as long as the object of this invention is not impaired.
According to the use to be made of the final product, it is also feasible to incorporate, in suitable proportion or proportions, one or more of other thermosetting resins (e.g., phenol resins and epoxy resins) and thermoplastic resins (e.g., polyethylene, polypropylene, polyamide, polycarbonate, polysulfone, polyethersulfone, polyether ether ketone, modified polyphenylene oxide, polyphenylene sulfide and fluoroplastics) and/or one or more of fibrous reinforcing materials such as glass fibers, aromatic polyamide fibers, alumina fibers and potassium titanate fibers.
The thermosetting resin composition according to this invention is formed or molded for practical use by a method known per se in the art, for example, by compression molding, transfer molding, extrusion molding or injection molding.
EXAMPLES 1-3
A powder mixture, which had been obtained in advance by mixing 1057 g (2 moles) of 4,4'-bis(3-maleimidophenoxy)-biphenyl and 368 g (1 mole) of 4.4'-bis(3-aminophenoxy)biphenyl, was charged in a stainless steel vessel equipped with a stirrer, a reflux condenser and a nitrogen gas inlet tube. They were heated, molten and reacted at 180° C. for 20 minutes. The reaction product was then cooled to room temperature. The reaction product, which had been solidified into a transparent glass-like mass of a brown color, was broken into pieces and taken out of the vessel. It was ground further in a mortar and then sifted through a 60-mesh sieve, thereby obtaining a fine yellow powder of a partly-hardened polyaminobismaleimide resin. Yield: 1390 g (97.5%). Its softening temperature was 118° C., while its gelling time was 59-75 seconds at 200° C.
With 100 parts-by-weight portions of the thus-obtained polyaminobismaleimide resins, quartz powder having a particle size distribution of 1-50 μm was mixed in the amounts shown in Table 1 at room temperature. After the resultant mixtures were separately kneaded at 150° C. and then cooled, they were ground to obtain molding materials. Each of the thus-obtained molding materials was formed into tablets. After the resultant tablets were preheated, they were separately filled in cavities (10×80×4 mm) of a mold which was heated at 220° C. to perform transfer molding, thereby obtaining specimens for the measurement of mechanical properties. Their Izod impact tests (unnotched), bend tests (measurement temperatures: 25° C. and 180° C.) and measurement of heat distortion temperature (18.5 kg/cm 2 ) were carried out in accordance with JIS K-6911. The results shown in Table 1 were obtained.
EXAMPLE 4
With 100 parts-by-weight portions of a polyaminobismaleimide resin obtained in the same manner as in Examples 1-3, amorphous quartz glass powder having a particle size distribution of 1-50 μm was mixed at room temperature. After the resultant mixture was kneaded at 150° C. and then cooled, it was ground to obtain a molding material. The procedure of Examples 1-3 was thereafter followed to obtain the results shown in Table 1.
EXAMPLE 5
To 100 parts-by-weight portions of a polyaminobismaleimide resin obtained from 529 g (1 mole) of 4,4'-bis(3-maleimidophenoxy)biphenyl and 111 g (0.3 mole) of 4,4'-bis(3-aminophenoxy)biphenyl in the same manner as in Examples 1-3, the same quartz powder as those employed in Examples 1-3 was added in the amount shown in Table 1. The procedure of Examples 1-3 was thereafter followed to obtain the results shown in Table 1.
EXAMPLE 6
To 100 parts-by-weight portions of a polyaminobismaleimide resin obtained from 529 g (1 mole) of 4,4'-bis(3-maleimidophenoxy)biphenyl and 258 g (0.7 mole) of 4,4'-bis(3-aminophenoxy)biphenyl in the same manner as in Examples 1-3, the same quartz powder as those employed in Examples 1-3 was added in the amount shown in Table 1. The procedure of Examples 1-3 was thereafter followed to obtain the results shown in Table 1.
EXAMPLES 7-21 AND COMPARATIVE EXAMPLES 1-3
To 100 parts-by-weight portions of polyaminobismaleimide resins obtained by using at a molar ratio of 2:1 bismaleimide compounds and diamine compounds shown in Table 1, the same quartz powder as those employed in Examples 1-3 was added in the amounts shown in Table 1. The procedure of Examples 1-3 was thereafter followed to obtain the results shown in Table 1.
COMPARATIVE EXAMPLE 4
With 67 parts by weight of a novolak cresolepoxy resin (epoxy equivalent: 215), 33 parts by weight of a novolak phenol resin (phenol equivalent: 107) and 250 parts by weight of the same quartz powder as those employed in Examples 1-3 were mixed at room temperature. After the resultant mixture was kneaded at 90°-95° C. and then cooled, it was ground to obtain a molding material. The procedure of Examples 1-3 was thereafter followed to obtain the results shown in Table 1.
COMPARATIVE EXAMPLE 5
With 67 parts by weight of a novolak cresolepoxy resin (epoxy equivalent: 215), 33 parts by weight of a novolak phenol resin (phenol equivalent: 107) and 250 parts by weight of the same amorphous quartz glass powder as that employed in Example 4 were mixed at room temperature. After the resultant mixture was kneaded at 90°-95° C. and then cooled, it was ground to obtain a molding material. The procedure of Examples 1-3 was thereafter followed to obtain the results shown in Table 1.
EXAMPLES 22-24
With 100 parts-by-weight portions of polyaminobismaleimide resin powder obtained in the same manner as in Examples 1-3, alumina powder having a particle size distribution of 1-50 μm was mixed in the amounts shown in Table 2 at room temperature. After the resultant mixtures were separately kneaded at 150° C. and then cooled, they were ground to obtain molding materials. The procedure of Examples 1-3 was thereafter followed to obtain the results shown in Table 2.
EXAMPLE 25
To 100 parts-by-weight portions of a polyaminobismaleimide resin obtained from 529 g (1 mole) of 4,4'-bis(3-maleimidophenoxy)biphenyl and 111 g (0.3 mole) of 4,4'-bis(3-aminophenoxy)biphenyl in the same manner as in Examples 22-24, the same alumina powder as those employed in Examples 22-24 was added in the amount shown in Table 2. The procedure of Examples 22-24 was thereafter followed to obtain the results shown in Table 2.
EXAMPLE 26
To 100 parts-by-weight portions of a polyaminobismaleimide resin obtained from 529 g (1 mole) of 4,4'-bis(3-maleimidophenoxy)biphenyl and 258 g (0.7 mole) of 4,4'-bis(3-aminophenoxy)biphenyl in the same manner as in Examples 22-24, the same alumina powder as those employed in Examples 22-24 was added in the amount shown in Table 2. The procedure of Examples 22-24 was thereafter followed to obtain the results shown in Table 2.
EXAMPLES 27-41 AND COMPARATIVE EXAMPLES 6-8
To 100 parts-by-weight portions of polyaminobismaleimide resins obtained by using at a molar ratio of 2:1 bismaleimide compounds and diamine compounds shown in Table 2, the same alumina powder as those employed in Examples 22-24 was added in the amounts shown in Table 2. The procedure of Examples 22-24 was thereafter followed to obtain the results shown in Table 2.
COMPARATIVE EXAMPLE 9
With 67 parts by weight of a novolak cresolepoxy resin (epoxy equivalent: 215), 33 parts by weight of a novolak phenol resin (phenol equivalent: 107) and 250 parts by weight of the same alumina powder as those employed in Examples 22-24 were mixed at room temperature. After the resultant mixture was kneaded at 90°-95° C. and then cooled, it was ground to obtain a molding material. The procedure of Examples 22-24 was thereafter followed to obtain the results shown in Table 2.
EXAMPLES 42-44
With 100 parts-by-weight portions of polyaminobismaleimide resin powder obtained in the same manner as in Examples 1-3, silicon carbide powder having a particle size distribution of 1-50 μm was mixed in the amounts shown in Table 3 at room temperature. After the resultant mixtures were separately kneaded at 150° C. and then cooled, they were ground to obtain molding materials. The procedure of Examples 1-3 was thereafter followed to obtain the results shown in Table 3.
EXAMPLE 45
To 100 parts-by-weight portions of a polyaminobismaleimide resin obtained from 529 g (1 mole) of 4,4'-bis(3-maleimidophenoxy)biphenyl and 111 g (0.3 mole) of 4,4'-bis(3-aminophenoxy)biphenyl in the same manner as in Examples 42-44, the same silicon carbide powder as those employed in Examples 42-44 was added in the amount shown in Table 3. The procedure of Examples 42-44 was thereafter followed to obtain the results shown in Table 3.
EXAMPLE 46
To 100 parts-by-weight portions of a polyaminobismaleimide resin obtained from 529 g (1 mole) of 4,4'-bis(3-maleimidophenoxy)biphenyl and 258 g (0.7 mole) of 4,4'-bis(3-aminophenoxy)biphenyl in the same manner as in Examples 42-44, the same silicon carbide powder as those employed in Examples 42-44 was added in the amount shown in Table 3. The procedure of Examples 42-44 was thereafter followed to obtain the results shown in Table 3.
EXAMPLES 47-61 AND COMPARATIVE EXAMPLES 10-12
To 100 parts-by-weight portions of polyaminobismaleimide resins obtained by using at a molar ratio of 2:1 bismaleimide compounds and diamine compounds shown in Table 3, the same silicon carbide powder as those employed in Examples 42-44 was added in the amounts shown in Table 3. The procedure of Examples 42-44 was thereafter followed to obtain the results shown in Table 3.
COMPARATIVE EXAMPLE 13
With 67 parts by weight of a novolak cresolepoxy resin (epoxy equivalent: 215), 33 parts by weight of a novolak phenol resin (phenol equivalent: 107) and 250 parts by weight of the same silicon carbide powder as those employed in Examples 42-44 were mixed at room temperature. After the resultant mixture was kneaded at 90°-95° C. and then cooled, it was ground to obtain a molding material. The procedure of Examples 42-44 was thereafter followed to obtain the results shown in Table 3.
TABLE 1__________________________________________________________________________ Coefficient Izod impact Heat distor- Flexural of flexural strength tion temp.Resin composition (parts by weight) strength elasticity (unnotched) temperatureResin (100 parts by weight) Silica (Kg/mm.sup.2) (Kg/mm.sup.2) (Kg · cm/cm) (18.5 kg/cm.sup.2)Bismaleimide Diamine powder 25° C. 180° C. 25° C. 180° C. 25° C. (°C.)__________________________________________________________________________Ex. 1 4,4'-Bis(3-maleimido- 4,4'-Bis(3-amino- 50* 18.0 12.1 995 750 26 247 phenoxy)biphenyl phenoxy)biphenylEx. 2 4,4'-Bis(3-maleimido- 4,4'-Bis(3-amino- 250* 22.0 15.1 1590 1190 32 269 phenoxy)biphenyl phenoxy)biphenylEx. 3 4,4'-Bis(3-maleimido- 4,4'-Bis(3-amino- 400* 23.2 16.2 1720 1290 36 285 phenoxy)biphenyl phenoxy)biphenylEx. 4 4,4'-Bis(3-maleimido- 4,4'-Bis(3-amino- 250** 22.0 16.5 1570 1180 32 265 phenoxy)biphenyl phenoxy)biphenylEx. 5 4,4'-Bis(3-maleimido- 4,4'-Bis(3-amino- 250* 21.5 14.3 1540 1070 30 268 phenoxy)biphenyl phenoxy)biphenylEx. 6 4,4'-Bis(3-maleimido- 4,4'-Bis(3-amino- 250* 22.0 15.2 1600 1100 31 265 phenoxy)biphenyl phenoxy)biphenylEx. 7 4,4'-Bis(3-maleimido- 1,3-Bis(3-amino- 250* 21.5 14.8 1550 1160 32 267 phenoxy)biphenyl phenoxy)benzeneEx. 8 4,4'-Bis(3-maleimido- 2,2-Bis[4-(3-amino- 250* 21.5 15.3 1600 1230 32 270 phenoxy)biphenyl phenoxy)phenyl]propaneEx. 9 4,4'-Bis(3-maleimido- Bis[4-(3-aminophenoxy)- 250* 20.9 14.5 1610 1210 32 270 phenoxy)biphenyl phenyl]sulfideEx. 10 1,3-Bis(3-maleimido- 4,4'-Bis(3-amino- 250* 20.0 13.7 1610 1170 32 270 phenoxy)benzene phenoxy)biphenylEx. 11 1,3-Bis(3-maleimido- 1,3-Bis(3-amino- 250* 20.0 14.0 1610 1200 33 272 phenoxy)benzene phenoxy)benzeneEx. 12 1,3-Bis(3-maleimido- 2,2-Bis[4-(3-amino- 250* 21.5 14.6 1650 1240 31 269 phenoxy)benzene phenoxy)phenyl]propaneEx. 13 1,3-Bis(3-maleimido- BIs[4-(3-aminophenoxy)- 250* 22.0 14.3 1590 1170 31 270 phenoxy)benzene phenyl]sulfideEx. 14 2,2-Bis[4-(3-male- 4,4'-Bis(3-amino- 250* 21.7 14.5 1570 1180 33 271 imidophenoxy)phenyl)- phenoxy)biphenyl propaneEx. 15 2,2-Bis[4-(3-male- 1,3-Bis(3-amino- 250* 22.5 15.2 1540 1160 32 267 imidophenoxy)phenyl)- phenoxy)benzene propaneEx. 16 2,2-Bis[4-(3-male- 2,2-Bis[4-(3-amino- 250* 20.5 13.9 1600 1220 32 270 imidophenoxy)phenyl)- phenoxy)phenyl]propane propaneEx. 17 2,2-Bis[4-(3-male- Bis[4-(3-aminophenoxy)- 250* 21.6 15.1 1580 1170 31 270 imidophenoxy)phenyl)- phenyl]sulfide propaneEx. 18 Bis[4-(3-maleimido- 4,4'-Bis(3-amino- 250* 21.5 15.3 1620 1200 30 273 phenoxy)phenyl]- phenoxy)biphenyl sulfideEx. 19 Bis[4-(3-maleimido- 1,3-Bis(3-amino- 250* 22.0 14.3 1520 1140 33 268 phenoxy)phenyl]- phenoxy)benzene sulfideEx. 20 Bis[4-(3-maleimido- 2,2-Bis[4-(3-amino- 250* 21.5 14.2 1630 1210 32 269 phenoxy)phenyl]- phenoxy)phenyl]propane sulfideEx. 21 Bis[4-(3-maleimido- Bis[4-(3-aminophenoxy)- 250* 20.5 14.5 1620 1210 32 270 phenoxy)phenyl]- phenyl]sulfide sulfideComp. 4,4'-Bis(3-maleimido- 4,4'-Bis(3-amino- 0 15.6 9.9 338 253 20 242Ex. 1 phenoxy)biphenyl phenoxy)biphenylComp. 4,4'-Bis(3-maleimido- 4,4'-Bis(3-amino- 20* 16.0 10.0 465 295 21 243Ex. 2 phenoxy)biphenyl phenoxy)biphenylComp. 4,4'-Bis(3-maleimido- 4,4'-Bis(3-amino- 850* Molding was infeasible dueEx. 3 phenoxy)biphenyl phenoxy)biphenyl to lack of melt fluidityComp. Novolak cresol-epoxy Novolak phenol resin 250* 13.2 2.0 1570 100 32 148Ex. 4 resin (epoxy equiva- (phenol equivalent: lent: 215) 67 parts 107) 33 parts by by weight weightComp. Novolak cresol-epoxy Novalak phenol resin 250** 14.5 1.7 1500 90 30 150Ex. 5 resin (epoxy equiva- (phenol equivalent: lent: 215) 67 parts 107) 33 parts by by weight weight__________________________________________________________________________ *Quartz powder; **Amorphous quartz glass powder.
TABLE 2__________________________________________________________________________ Coefficient Izod impact Heat distor- Flexural of flexural strength tion temp.Resin composition (parts by weight) strength elasticity (unnotched) temperatureResin (100 parts by weight) Alumina (Kg/mm.sup.2) (Kg/mm.sup.2) (Kg · cm/cm) (18.5 kg/cm.sup.2)Bismaleimide Diamine powder 25° C. 180° C. 25° C. 180° C. 25° C. (°C.)__________________________________________________________________________Ex. 22 4,4'-Bis(3-maleimido- 4,4'-Bis(3-amino- 50 18.0 12.0 990 745 27 246Ex. 23 4,4'-Bis(3-maleimido- 4,4'-Bis(3-amino- 250 22.0 14.8 1510 1170 32 269 phenoxy)biphenyl phenoxy)biphenylEx. 24 4,4'-Bis(3-maleimido- 4,4'-Bis(3-amino- 400 24.5 16.4 1700 1260 35 285 phenoxy)biphenyl phenoxy)biphenylEx. 25 4,4'-Bis(3-maleimido- 4,4'-Bis(3-amino- 250 21.8 14.6 1520 1155 31 268 phenoxy)biphenyl phenoxy)biphenylEx. 26 4,4'-Bis(3-maleimido- 4,4'-Bis(3-amino- 250 22.0 14.7 1500 1160 31 267 phenoxy)biphenyl phenoxy)biphenylEx. 27 4,4'-Bis(3-maleimido- 1,3-Bis(3-amino- 250 22.0 14.6 1500 1170 32 268 phenoxy)biphenyl phenoxy)benzeneEx. 28 4,4'-Bis(3-maleimido- 2,2-Bis[4-(3-amino- 250 22.2 14.6 1500 1170 32 268 phenoxy)biphenyl phenoxy)phenyl]propaneEx. 29 4,4'-Bis(3-maleimido- Bis[4-(3-aminophenoxy)- 250 22.2 14.8 1510 1180 33 268 phenoxy)biphenyl phenyl]sulfideEx. 30 1,3-Bis(3-maleimido- 4,4'-Bis(3-amino- 250 21.9 14.6 1500 1160 32 268 phenoxy)benzene phenoxy)biphenylEx. 31 1,3-Bis(3-maleimido- 1,3-Bis(3-amino- 250 22.0 14.8 1490 1160 33 268 phenoxy)benzene phenoxy)benzeneEx. 32 1,3-Bis(3-maleimido- 2,2-Bis[4-(3-amino 250 22.0 14.8 1520 1160 33 268 phenoxy)benzene phenoxy)phenyl]propaneEx. 33 1,3-Bis(3-maleimido- Bis[4-(3-aminophenoxy)- 250 21.8 15.0 1550 1170 31 267 phenoxy)benzene phenyl]sulfideEx. 34 2,2-Bis[4-(3-male- 4,4'-Bis(3-amino- 250 21.9 15.2 1540 1180 32 267 imidophenoxy)phenyl)- phenoxy)biphenyl propaneEx. 35 2,2-Bis[4-(3-male- 1,3-Bis(3-amino- 250 22.0 15.0 1520 1190 32 267 imidophenoxy)phenyl)- phenoxy)benzene propaneEx. 36 2,2-Bis[4-(3-male- 2,2-Bis[4-(3-amino- 250 22.0 15.0 1520 1160 32 269 imidophenoxy)phenyl)- phenoxy)phenyl]propane propaneEx. 37 2,2-Bis[4-(3-male- Bis[4-(3-aminophenoxy)- 250 21.5 14.9 1520 1170 31 268 imidophenoxy)phenyl)- phenyl]sulfide propaneEx. 38 Bis[4-(3-maleimido- 4,4'-Bis(3-amino- 250 22.0 14.9 1510 1160 32 268 phenoxy)phenyl]- phenoxy)biphenyl sulfideEx. 39 Bis[4-(3-maleimido- 1,3-Bis(3-amino- 250 21.5 14.5 1490 1170 32 269 phenoxy)phenyl]- phenoxy)benzene sulfideEx. 40 Bis[4-(3-maleimido- 2,2-Bis[4-(3-amino- 250 22.0 15.0 1500 1200 32 268 phenoxy)phenyl]- phenoxy)phenyl]propane sulfideEx. 41 Bis[4-(3-maleimido- Bis[4-(3-aminophenoxy)- 250 22.0 14.8 1500 1200 31 268 phenoxy)phenyl]- phenyl]sulfide sulfideComp. 4,4'-Bis(3-maleimido- 4,4'-Bis(3-amino- 0 15.6 9.9 338 253 20 242Ex. 6 phenoxy)biphenyl phenoxy)biphenylComp. 4,4'-Bis(3-maleimido- 4,4'-Bis(3-amino- 20 15.9 10.0 460 290 20 243Ex. 7 phenoxy)biphenyl phenoxy)biphenylComp. 4,4'-Bis(3-maleimido- 4,4'-Bis(3-amino- 850 Molding was infeasible dueEx. 8 phenoxy)biphenyl phenoxy)biphenyl to lack of melt fluidityComp. Novolak cresol-epoxy Novolak phenol resin 250 13.2 2.0 1570 100 32 148Ex. 9 resin (epoxy equiva- (phenol equivalent: lent: 215) 67 parts 107 (33 parts by by weight weight__________________________________________________________________________
TABLE 3__________________________________________________________________________ Coefficient Izod impact Heat distor- Flexural of flexural strength tion temp.Resin composition (parts by weight) Silicon strength elasticity (unnotched) temperatureResin (100 parts by weight) Carbide (Kg/mm.sup.2) (Kg/mm.sup.2) (Kg · cm/cm) (18.5 kg/cm.sup.2)Bismaleimide Diamine powder 25° C. 180° C. 25° C. 180° C. 25° C. (°C.)__________________________________________________________________________Ex. 42 4,4'-Bis(3-maleimido- 4,4'-Bis(3-amino- 50 18.0 12.0 990 735 25 248 phenoxy)biphenyl phenoxy)biphenylEx. 43 4,4'-Bis(3-maleimido- 4,4'-Bis(3-amino- 250 21.5 14.9 1480 1120 30 268 phenoxy)biphenyl phenoxy)biphenylEx. 44 4,4'-Bis(3-maleimido- 4,4'-Bis(3-amino- 400 23.0 16.0 1690 1210 34 282 phenoxy)biphenyl phenoxy)biphenylEx. 45 4,4'-Bis(3-maleimido- 4,4'-Bis(3-amino- 250 22.0 15.0 1470 1100 30 267 phenoxy)biphenyl phenoxy)biphenylEx. 46 4,4'-Bis(3-maleimido- 4,4'-Bis(3-amino- 250 21.5 14.8 1470 1150 30 268 phenoxy)biphenyl phenoxy)biphenylEx. 47 4,4'-Bis(3-maleimido- 1,3-Bis(3-amino- 250 22.0 14.8 1450 1120 30 267 phenoxy)biphenyl phenoxy)benzeneEx. 48 4,4'-Bis(3-maleimido- 2,2-Bis[4-(3-amino- 250 21.0 14.9 1460 1120 31 267 phenoxy)biphenyl phenoxy)phenyl]propaneEx. 49 4,4'-Bis(3-maleimido- Bis[4-(3-aminophenoxy)- 250 21.0 15.0 1450 1130 29 266 phenoxy)biphenyl phenyl]sulfideEx. 50 1,3-Bis(3-maleimido- 4,4'-Bis(3-amino- 250 21.5 14.8 1470 1120 30 267 phenoxy)benzene phenoxy)biphenylEx. 51 1,3-Bis(3-maleimido- 1,3-Bis(3-amino- 250 21.0 14.8 1460 1120 30 267 phenoxy)benzene phenoxy)benzeneEx. 52 1,3-Bis(3-maleimido- 2,2-Bis[4-(3-amino- 250 22.0 15.0 1460 1170 30 268 phenoxy)benzene phenoxy)phenyl]propaneEx. 53 1,3-Bis(3-maleimido- Bis[4-(3-aminophenoxy)- 250 22.0 14.9 1470 1180 29 267 phenoxy)benzene phenyl]sulfideEx. 54 2,2-Bis[4-(3-male- 4,4'-Bis(3-amino- 250 21.0 15.0 1460 1100 31 265 imidophenoxy)phenyl)- phenoxy)biphenyl propaneEx. 55 2,2-Bis[4-(3-male- 1,3-Bis(3-amino- 250 22.0 14.9 1480 1080 30 267 imidophenoxy)phenyl)- phenoxy)benzene propaneEx. 56 2,2-Bis[4-(3-male- 2,2-Bis[4-(3-amino- 250 21.5 14.7 1480 1100 30 267 imidophenoxy)phenyl)- phenoxy)phenyl]propane propaneEx. 57 2,2-Bis[4-(3-male- Bis[4-(3-aminophenoxy)- 250 21.5 14.9 1480 1100 31 267 imidophenoxy)phenyl)- phenyl]sulfide propaneEx. 58 Bis[4-(3-maleimido- 4,4'-Bis(3-amino- 250 21.0 15.2 1480 1120 29 265 phenoxy)phenyl]- phenoxy)biphenyl sulfideEx. 59 Bis[4-(3-maleimido- 1,3-Bis(3-amino- 250 21.0 15.0 1480 1110 31 266 phenoxy)phenyl]- phenoxy)benzene sulfideEx. 60 Bis[4-(3-maleimido- 2,2-Bis[4-(3-amino- 250 21.5 14.8 1470 1120 31 267 phenoxy)phenyl]- phenoxy)phenyl]propane sulfideEx. 61 Bis[4-(3-maleimido- Bis[4-(3-aminophenoxy)- 250 21.0 14.8 1470 1120 31 266 phenoxy)phenyl]- phenyl]sulfide sulfideComp. 4,4'-Bis(3-amleimido- 4,4'-Bis(3-amino- 0 15.6 9.9 338 253 20 242Ex. 10 phenoxy)biphenyl phenoxy)biphenylComp. 4,4'-Bis(3-amleimido- 4,4'-Bis(3-amino- 20 16.0 9.9 460 2850 21 243Ex. 11 phenoxy)biphenyl phenoxy)biphenylComp. 4,4'-Bis(3-amleimido- 4,4'-Bis(3-amino- 850 Molding was infeasible dueEx. 12 phenoxy)biphenyl phenoxy)biphenyl to lack of melt fluidityComp. Novolak cresol-epoxy Novolak phenol resin 250 13.2 2.0 1570 100 32 148Ex. 13 resin (epoxy equiva- (phenol equivalent: lent: 215) 67 parts 107) 33 parts by by weight weight__________________________________________________________________________ | A thermosetting resin composition formed of a polyaminobismaleimide resin, which is composed of a bismaleimide compound and a diamine compound, and a powdery inorganic filler. The composition has excellent heat resistance as well as superb mechanical properties at high temperature not to mention room temperature, and is expected to find wide-spread commerical utility in electric and electronic components such as sealing materials, sockets and connectors and other applications. | 2 |
BACKGROUND OF THE INVENTION
The present invention relates to a method and apparatus for monitoring the operation of a component which is located in a sealed enclosure.
Many types of systems include movable components which are not accessible from outside the system and whose operational status cannot be readily determined. This is frequently the case in fluid-flow systems which, by their nature, contain flow-control components that are not accessible from the exterior, at least while the system is in operation.
It is known to monitor the operating state of components in a fluid-flow system indirectly by monitoring the fluid pressure upstream and downstream of the component, and/or the velocity of fluid-flow past the component. Such monitoring systems are relatively costly and are themselves prone to failure and malfunction. Moreover, each such monitoring device communicates with the fluid-flow path through an opening which must itself be sealed.
SUMMARY OF THE INVENTION
It is an object of the present invention to monitor the operating state of movable components in a sealed enclosure in a simplified manner.
Another object of the invention is to monitor the operating state of such components without penetrating the enclosure.
A further object of the invention is to monitor the operating state of such components using a monitoring arrangement which is simple and inexpensive.
The above and other objects are achieved, according to the present invention, by a method for monitoring the operation of a component which is located in a sealed enclosure and is movable into a selected operating position in response to an activating signal, comprising:
generating a short duration acoustic signal in the enclosure in response to the movement of the component into the selected operating position;
sensing the acoustic signal at the exterior of the sealed enclosure; and
determining the time relationship between the activating signal and the acoustic signal.
The objects of the invention are further achieved by a device for monitoring the operation of a component which is located in a sealed enclosure and is movable into a selected operating position in response to an activating signal, which device comprises:
means for generating a short duration acoustic signal in the enclosure in response to the movement of the component into the selected operating position;
sensing means acoustically coupled to the sealed enclosure and located at the exterior of the enclosure for sensing the acoustic signal ; and
monitoring means connected to the sensing means for determining the time relationship between the activating signal and the acoustic signal.
BRIEF DESCRIPTION OF THE DRAWING
The sole FIGURE is a partly cross-sectional, partly schematic view of a preferred embodiment of a monitoring device according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The FIGURE shows a pipeline 2 for conducting a fluid in the direction 4, the pipeline including a housing 6 containing a one-way valve component 8. Component 8 is supported by pivot arm 10 pivotally mounted on a base 12 fixed in housing 6.
An actuating mechanism (not shown) of any suitable, known type is connected to pivot arm 10 and is responsive to an electrical signal defining the flow-blocking state so as to rotate pivot arm 10 to bring valve component 8 into the position, shown in solid lines in the FIGURE, in which component 8 blocks flow along path 4. In certain systems, the valve component will not be brought to the fully closed position in response to a closing signal. When that signal disappears, or a signal defining the flow establishing state is produced, pivot arm 10 pivots to bring valve component 8 to the open position depicted by the broken outline 18.
According to the invention, an acoustic receiver 20, which may include an acoustic-to-electrical signal transducer and an amplifier, is acoustically coupled to pipeline 2 or housing 6 in that the acoustic sensor of receiver 20 is placed in contact with the outer wall of pipeline 2 or housing 6 at a location where the generated acoustic signal, or impulse, will be clearly received. Receiver 20 is operative to produce an output signal on line 22 representative of acoustic impulses transmitted through the portion of the wall of pipeline 2 or housing 6 to which receiver 20 is acoustically coupled. Line 22 is connected to a logic member 24 which additionally receives the above-mentioned flow-blocking signal via a line 26.
According to one possible implementation of the invention, the creation of a flow-blocking signal moves pivot arm 10 in a manner such that the closing movement produces an impact of valve component 8 against a seating surface associated with pipeline 2 sufficient to apply to receiver 20 an acoustic signal producing a discernable pulse signal on line 22. In this case, it may be preferable to mount receiver 20 at a location close to the flow-blocking position of component 8.
The duration of the flow-blocking signal on line 26 is selected to be of a sufficient length to at least partially overlap the resulting signal pulse appearing on line 22 in response to the closing movement of valve component 8. This partial overlap will be interpreted by logic member 24 as a proper valve closing operation, so that no fault signal will be emitted on output line 28. If, on the other hand, a flow-blocking signal appearing on line 26 is not associated with an at least partially overlapping signal on line 22, this constitutes an indication of a faulty valve closing operation, and logic member 24 will supply an alarm signal on line 28. Thus, logic member 24 functions, in effect, as a logic ANDNOT member, and could be constituted by such a member, possibly together with appropriate amplifying and pulse shaping circuitry.
In many cases, the closing movement of valve component 8 will not directly produce a sufficient acoustic signal. For example, in high flow systems, an initial closing signal will only move component 8 partially to its closed position, full closure occurring at a later time after flow has otherwise been blocked. In this case, in further accordance with the invention, housing 6 is equipped with an auxiliary acoustic signal generating element which operates in response to movement of valve component 8 to its flow-blocking position. In the illustrated embodiment, this auxiliary element is a pivotal member 30 supported on a base 32 and biased, as by a leaf spring 34, into the illustrated position. In the illustrated embodiment, spring 34 is fixed to member 30 and is slidable relative to the interior wall of housing 6.
When pivot member 30 is in the illustrated position and valve component 8 is in the position 18, component 8 and member 30 will be in contact.
At least in the region where these two parts are in contact, one of them is made of a magnetic material and the other of a magnetizable material so that a magnetic attraction exists therebetween.
When, upon appearance of a flow-blocking signal, valve component 8 begins to move toward its flow-blocking position, member 30 will be pivoted in opposition to its associated biassing force until a point is reached at which the magnetic contact between valve component 8 and member 30 is broken, either because the biassing force exceeds the magnetic attraction force or because member 30 has reached the end of its permissable travel path. After contact has been broken, member 30 is driven by its associated biassing force to strike housing 6 and thus produce an acoustic signal which is processed by receiver 20. The resulting output signal is then interpreted in logic member 24 in the same manner as the signal described above.
It can thus be seen that the present invention offers, in addition to being structurally simple, reliable, and inexpensive, the possibility of monitoring the complete component operation in that an alarm signal will be produced regardless of the cause of component malfunction. Thus, in the case of the valve illustrated in the FIGURE, an alarm signal will be produced regardless of whether malfunction is due to failure of the associated actuator to respond to the valve closing signal, failure of the linkage between the actuator and pivot arm 10, blockage of arm 10, or separation of component 8 from arm 10. In addition, when receiver 20 responds directly to impact of component 8 against its valve seat, incomplete valve closing will be detected.
If the activating signal employed to move valve component 8 to its valve-closing position has such a short duration that it can terminate before a proper acoustic signal is generated, then the activating signal can be employed to produce a pulse having a suitably long duration, and it will be this pulse which is applied to line 26. Conversely, if the activating signal has an unacceptably long duration, e.g. if the activating signal remains present as long as component 8 is in its valve closed position, then the leading edge of each activating signal can be used to generate a pulse of suitable duration, which is applied to line 26. In any event, according to the invention, each activating signal should serve to provide on line 26 a pulse having a duration which is sufficiently long to assure that it will overlap with the corresponding acoustic impulse, but short enough to assure that a spurious acoustic impulse will not produce a faulty indication of proper component operation.
While the illustrated embodiment relies on magnetic coupling between member 30 and component 8, it would equally be possible to establish a releasable mechanical connection therebetween.
According to further embodiments of the invention, acoustic receiver 20 can be thermally isolated from pipeline 2 or housing 6, for example by means of a standoff, so that the monitoring of components in a system conducting high temperature or low temperature fluids can be effected with a relatively inexpensive acoustic receiver.
Since a monitoring operation according to the present invention requires the detection of only relatively strong acoustic impulses, the acoustic receiver can be a relatively inexpensive device and its output signal need not be subjected to any type of measurement, analysis or shaping.
While the invention has been described with reference to the monitoring of a nonreturn valve, it will be appreciated that the monitoring method and devices according to the present invention can be employed to monitor the proper operation of any enclosed component which is to be moved to a defined position by an activating signal. The use of a separate movable member will be dictated in part by the nature of the component to be monitored and under consideration of whether that component, in its normal operation, will itself produce an acoustic pulse of sufficient magnitude.
It will be understood that the above description of the present invention is susceptible to various modifications, changes, and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims. | A method and device for monitoring the operation of a component which is located in a sealed enclosure and is movable into a selected operating position in response to an activating signal uses the steps of: generating a short-duration acoustic signal in the enclosure in response to the movement of the component into the selected operating position; sensing the acoustic signal at the exterior of the sealed enclosure; and determining the time relationship between the activating signal and the acoustic signal. The acoustic signal is generated by an element which is carried by or moveable with the component and which generates the acoustic signal by striking an interior surface of the enclosure when the component moves into the selected operating position. | 8 |
FIELD OF INVENTION
The present embodiments relate generally to ski goggles for adults or children with an integrated digital music player and earphones and a wireless connection to members of an audience watching downhill racers.
BACKGROUND
The present invention relates to ski goggles which are single lens or double lens and are used on adults or children.
Skiers who are training for the Olympics and for racing have used music broadcast over loudspeakers to learn rhythm to traverse moguls quickly. The broadcast music is land based typically at the bottom of the mogul field and is very loud, disturbing everyone around the race course. Typically, the announcer can not even speak or announce the names of skiers over the loud music needed for the racers.
A need has existed for a ski goggle that links to a broadcast system so the individual skier can hear the music, select audience members can hear the music, and broadcast of the music is optional to the slopes to stop the noise on the adjacent slopes during a race.
The noise is known to distract skiers, particularly children, who do not pay attention to their skiing, and crash into people breaking arms and causing damage. Such accidents have happened at Park City Ski Resort in Park City Utah, and at Killington Ski area in Killington Vt., and should be stopped, and not repeated.
A need has existed for a ski goggle that can hold numerous files of digital music such as an IPOD for use with the training of ski racers.
The present invention meets these needs.
BRIEF DESCRIPTION OF THE DRAWINGS
The detailed description will be better understood in conjunction with the accompanying drawings as follows:
FIG. 1 depicts a perspective view of the ski goggle with digital receiver and player embodiment.
FIG. 2 shows a face of a skier wearing the ski goggles with digital player and transmitter embodiment
FIG. 3 depicts a race slope with the racer wearing the ski goggle of FIG. 1 and audience members wearing synched receivers and the transmitter of the digital music file over a wireless connection.
The present embodiments are detailed below with reference to the listed Figures.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Before explaining the present embodiments in detail, it is to be understood that the embodiments are not limited to the particular embodiments and that it can be practiced or carried out in various ways.
FIG. 1 shows a ski goggle ( 10 ) having a face plate ( 12 ), a first side connector ( 14 ), and a second side connector ( 16 ) each having an adjustment device ( 18 ) and ( 20 ) to shorten or lengthen a strap ( 22 ) which goes around the head of a user (shown in FIG. 2 ).
A digital player ( 24 ) is secured in a housing ( 26 ) which is fastened, such as with locking fasteners ( 28 ), such as screws or alternatively a C-Clip (no shown) to one of the two connectors. The digital player can be a mini IPOD™, such as those sold by Apple computer company of California. The mini IPOD™ is a compact digital player which connects to a computer to download digital music files, and the player is battery operated with an integrated battery that is rechargeable. Alternatively, an MP3 player or a miniature radio can be used. The housing can be made of plastic, Velcro™ woven fabric, or elastic material.
The miniature digital player ( 24 ) connects to earphones ( 30 ) and ( 32 ) using a first wire ( 34 ) that goes from the digital player ( 24 ) across the faceplate ( 12 ) at the upper most portion to the connector ( 14 ) and then to the earphone ( 32 ) and a second wire ( 36 ) that goes from the digital player ( 24 ) to the connector ( 16 ) and then down to the earphone ( 30 ). Additionally, the miniature digital player ( 24 ) can be engaged with a mini-transmitter/receiver ( 38 ) removeably connected to the housing ( 26 ) and engaging the digital player with a wired connection ( 40 ). The mini-transmitter and receiver ( 38 ) is preferably an El-Pro wireless transmitter/receiver available from Elextromax of Houston Tex. This unit is small, and transmits over 2000 feet, which is the length of the typical mogul race course and has its own battery.
Audience members can wear receiver units to hear the transmissions from the digital player on the skier without the need to broadcast the loud music over the slopes causing crashes on adjacent slopes by kids cutting off skiers as they go to view the racers because of the loud music, and it is really loud. It is contemplated that the mini wireless transmitter/receiver can be a cell phone transmitting over a cell network.
FIG. 2 shows and embodiment of the digital player ( 28 ) in the housing ( 26 ) on the ski goggles ( 10 ) transmitter/receiver on the head of a user ( 42 ) with an earphone in each ear ( 46 ) and ( 48 ) respectively. This embodiment lets the skier practice the race runs with the digital music player, so that only the racer or the skier hears the music.
FIG. 3 shows the user ( 42 ) wearing the ski goggles with digital player and transmitter of FIG. 1 going down a ski slope broadcasting to a base station ( 50 ) having a repeater ( 52 ) for conveying the signal ( 54 ) from the user ( 42 ) to a first audience member ( 60 ) wearing receiving headphones ( 61 ) and a second audience member ( 62 ) wearing headphones ( 63 ) using a first repeater signal ( 56 ) and a second repeater signal ( 58 ). It is also contemplated that the user ( 42 ) could be able to transmit within range of the first and second audience members without a repeater unit ( 52 ), which are commonly available, particularly if the embodiment is a cellular connection. The headphones wearable by the audience members can be Zensonic Wireless Headphones from Morely, Australia with the repeater available from the same company.
It is contemplated that the first and second earphone in another embodiment can be in wireless communication with the miniature digital player.
It is important to the quality of the sound for practice and for use on television, as most of these races are televised that digital music and a digital music player be used, particularly since the cable channels are developing high definition images, they need high definition sound to go with it. The cable stations will not accept fuzzy music from the skier, and this invention enables the digital music to be broadcast directly from the user to the television receiver at the base of the ski slope for very high quality sound which was not previously available.
Use of the digital players with numerous skiers will generate a very high quality sound and image picture, which can be copied more easier and used to education and practice Olympic skiers with greater detail than every before.
In the use of the invention, this device will stop the crashes that occur on the adjacent ski slopes during races, which for people over 40 , would be really important and add a significant safety element to skiing not available before this invention.
The invention also contemplates a ski area having a ski slope with controlled music transmission that is not broadcast through loudspeakers, but only played through the unique ski goggles with digital player described herein. The ski area would have a ski slope, one or more of them with repeater units placed alongside the slope. A transmitter would be in communication with the repeater units. The ski area could play music on different slopes, rock and roll on one slope, jazz on another, new age on another and skiers would hear the different types of music, like music at a theme part by skiing with ski goggles that received the digital transmissions. It would be a new kind of entertainment for a ski area which would involve a premium paid by the skiers to rent or lease the units from the ski area to obtain the “total sensory” experience with the skiing. These ski goggles could have digital music receivers and earphones for receiving transmitted digital music; the repeater units placed on each slope for providing digital music transmissions without loudspeakers; and a transmitter for broadcasting the digital music on a frequency without the use of speakers in communication with the repeater units; digital music files available for transmission by the transmitter.
The invention contemplates a skiing theme park which has different music transmitted silently, so as not to bother other skiers, along each slope, rock and roll on the moguls, and cool jazz on the blue runs for an easy slide, for which skiers would pay a premium for the unique total sensory experience. More specifically, some of the different styles of music could be rock and roll, jazz, classical, new age, country, rap, top 40, big band, oldies, and combinations thereof.
While these embodiments have been described with emphasis on the preferred embodiments, it should be understood that within the scope of the appended claims, the embodiments might be practiced other than as specifically described herein. | A ski goggle with a digital sound playing system, a ski theme park and a ski slope having specially designed music transmitted over each slope. | 0 |
PRIORITY CLAIM
This application claims the benefit of U.S. Prov. Pat. App. No. 61/625,901 filed Apr. 18, 2012 and entitled LAUNCH DELAY OFFSET DATA FLOW PROTECTION.
BACKGROUND OF THE INVENTION
Known signal protection schemes include error correction using multiple channels and/or large static buffers. Such systems utilize excessive bandwidth and/or introduce relatively long latency. Although signal protection innovations are not a focus area of the telecommunications industry, improvements that are adopted by the industry have the potential to benefit large groups of consumers.
Field of Invention
This invention relates to the electrical arts. In particular, a signal is protected through the use of launch delay offset.
Discussion of the Related Art
Some signal protection systems are known. For example, some signal protection systems merely use simultaneous broadcasts on dual paths allowing for redundancy via switching between the paths. However, signal protection developments have not generally been a focus area of the telecommunications industry, perhaps due to the widespread use of the dual path protection system mentioned above. But, known systems generally suffer from one or more of hardware complexity, software complexity, high initial cost, high operating costs, large additions to required bandwidth, and signal degradation. Selected embodiments of the present invention provide solutions to one or more of these problems.
SUMMARY OF THE INVENTION
The present invention provides a signal protector utilizing dual data paths with a delay offset. In an embodiment, a data protection method comprises the steps of: providing data path A and data path B; each of the data paths extending between first and second stations; paths A and B transporting the same data; and, offsetting the data transported by path A from the data transported by path B by a time “t” such that following a simultaneous data loss on both paths during a time interval that is less than or equal to “t” an uninterrupted data flow can be recovered using a combination of information from both data paths.
In an embodiment, a data protection method comprising the steps of: providing a data transmitting block for receiving and forwarding data and a data receiving block for receiving the forwarded data and delivering data; coupling dual redundant data paths A and B between the data transmitting block and the data receiving block; configuring the transmitting block to transmit redundant data on data path B time “t” later than the data transmitted on path A; and, maintaining an uninterrupted flow of delivered data following a simultaneous data loss on both paths of duration less than or equal to “t” by merging data from paths A and B to provide at least some of the data delivered following to the data loss.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is described with reference to the accompanying figures. The figures, incorporated herein and forming part of the specification, illustrate the present invention and, together with the description, further serve to explain the principles of the invention and to enable a person skilled in the relevant art to make and use the invention.
FIG. 1 shows a protection system in accordance with the present invention.
FIG. 2 shows an embodiment of the protection system of FIG. 1 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The disclosure provided in the following pages describes examples of some embodiments of the invention. The designs, figures, and descriptions are non-limiting examples of certain embodiments of the invention. For example, other embodiments of the disclosed device may or may not include the features described herein. Moreover, disclosed advantages and benefits may apply to only certain embodiments of the invention and should not be used to limit the disclosed inventions.
Where parts are connected, descriptions herein include the term “coupled” which refers to either direct or indirect connections. Direct connections provide for a first part connected directly to a second part, for example A connected directly to B. Indirect connections provide for a first part connected indirectly to a second part, for example A connected indirectly to C via B.
FIG. 1 shows a signal protection system in accordance with the present invention 100 . Data paths A and B transport packet flows. As shown, Paths A and B are offset.
An exemplary Data Loss is shown. Here, Path A packets n+2, n+3, n+4 are lost and Path B packets n−1, n, n+1 are lost.
Recovery following the Data Loss is seen as follows. Path A is rebuilt using unlost packets n+2, n+3, n+4 of path B. Path B is rebuilt using unlost packets n−1, n, n+1 of Path A. In various embodiments, unlost packets are recovered and data streams are rebuilt using one or more of memories, buffers, switches, and other similar data processing equipment.
FIG. 2 shows the signal protection system of FIG. 1 implemented in a multi-channel audio transport system 200 . Both data feeds are in the same pipe with VLAN separation and in this example Feed B is delayed with respect to Feed A by 70 ms. As shown, the feeds extend between an encoder originating the data and a decoder processing the data forwarded by the encoder.
In various embodiments this data protection system enables recovery from simultaneous data loss in redundant, offset data paths. And, in various embodiments, dual path synchronized transmission data protection systems are adapted to implement the delay offset of the present invention.
In an example utilizing an embodiment of the present invention, a national radio network entity operating a private IP network implemented the present invention to resolve short, simultaneous data losses on dual diverse paths through the network where disturbances were less than 50 milliseconds in duration. The solution provides at a transmitting end a network feed source and a network adapter for delaying one of redundant network feeds by 70 milliseconds. Exemplary equipment includes a network adapter in the form of a Nevion Ventura VS906 IP Media Edge Adapter. With an audio input, the adapter provides dual redundant IP data flows carrying the audio information.
Receiving equipment provides delay equalization for the redundant paths and adjusts for both network delay and artificial delay to create one integral feed. A complementary receiving end adapter takes in the two network data flows and merges them to provide a merged data flow from which the audio information is decapsulated. This technique provides uninterrupted delivery of the transported audio information despite short, simultaneous network disturbances. Skilled artisans will of course recognize the present invention is not limited to particular transmission media or information transmission protocols.
While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not limitation. It will be apparent to those skilled in the art that various changes in the form and details can be made without departing from the spirit and scope of the invention. As such, the breadth and scope of the present invention should not be limited by the above-described exemplary embodiments, but should be defined only in accordance with the following claims and equivalents thereof. | A signal protector utilizes a dual data path delay offset enabling signal recovery on both paths following simultaneous data loss on both paths. | 6 |
FIELD OF THE INVENTION
[0001] The present invention relates to novel crystalline forms of a dipeptidyl peptidase-IV inhibitor. More particularly, the invention relates to novel crystalline forms of (2R,3S,5R)-2-(2,5-Difluorophenyl)-5-[2-(methylsulfonyl)-2,6-dihydropyrrolo[3,4-c]pyrazol-5(4H)-yl]tetrahydro-2H-pyran-3-amine, which is a potent, long acting inhibitor of dipeptidyl peptidase-IV. These novel crystalline forms, are useful for the treatment and prevention of diseases and conditions for which an inhibitor of dipeptidyl peptidase-IV is indicated, in particular Type 2 diabetes, obesity, and high blood pressure. The invention further concerns pharmaceutical compositions comprising the novel crystalline forms of the present invention useful to treat Type 2 diabetes, obesity, and high blood pressure as well as processes for the preparation of such forms and their pharmaceutical compositions.
BACKGROUND OF THE INVENTION
[0002] Inhibition of dipeptidyl peptidase-IV (DP-IV), an enzyme that inactivates both glucose-dependent insulinotropic peptide (GIP) and glucagon-like peptide 1 (GLP-1), represents a novel approach to the treatment and prevention of Type 2 diabetes, also known as non-insulin dependent diabetes mellitus (NIDDM). The therapeutic potential of DP-IV inhibitors for the treatment of Type 2 diabetes has been reviewed: C. F. Deacon and J. J. Hoist, “Dipeptidyl peptidase IV inhibition as an approach to the treatment and prevention of Type 2 diabetes: a historical perspective,” Biochem. Biophys. Res. Commun., 294: 1-4 (2000); K. Augustyns, et al., “Dipeptidyl peptidase IV inhibitors as new therapeutic agents for the treatment of Type 2 diabetes,” Expert. Opin. Ther. Patents, 13: 499-510 (2003); D. J. Drucker, “Therapeutic potential of dipeptidyl peptidase IV inhibitors for the treatment of Type 2 diabetes,” Expert Opin. Investig. Drugs, 12: 87-100 (2003); and M. A. Nauck et al., “Incretins and Their Analogues as New Antidiabetic Drugs,” Drug News Perspect., 16: 413-422 (2003).
[0003] WO 2010/056708 (published 20 May 2010), assigned to Merck & Co., describes a class of aminotetrahydropyrans, which are potent inhibitors of DP-IV and therefore useful for the treatment of Type 2 diabetes. Specifically disclosed in WO 2010/056708 is (2R,3S,5R)-2-(2,5-Difluorophenyl)-5-[2-(methylsulfonyl)-2,6-dihydropyrrolo[3,4-c]pyrazol-5(4H)-yl]tetrahydro-2H-pyran-3-amine.
[0004] However, the applicants have now discovered novel crystalline forms of (2R,3S,5R)-2-(2,5-Difluorophenyl)-5-[2-(methylsulfonyl)-2,6-dihydropyrrolo[3,4-c]pyrazol-5(4H)-yl]tetrahydro-2H-pyran-3-amine (Compound I).
SUMMARY OF THE INVENTION
[0005] The present invention is concerned with novel crystalline forms of the dipeptidyl peptidase-IV (DP-IV) inhibitor (2R,3S,5R)-2-(2,5-Difluorophenyl)-5-[2-(methylsulfonyl)-2,6-dihydropyrrolo[3,4-c]pyrazol-5(4H)-yl]tetrahydro-2H-pyran-3-amine (Compound I). Certain crystalline forms, have advantages in the preparation of pharmaceutical compositions of (2R,3S,5R)-2-(2,5-Difluorophenyl)-5-[2-(methylsulfonyl)-2,6-dihydropyrrolo[3,4-c]pyrazol-5(4H)-yl]tetrahydro-2H-pyran-3-amine, such as ease of processing and crystallisation, handling, stability to stress and dosing. In particular, they exhibit improved physicochemical properties, such as stability to stress, rendering them particularly suitable for the manufacture of various pharmaceutical dosage forms. The invention also concerns pharmaceutical compositions containing the novel forms thereof, as well as methods for using them as DP-IV inhibitors, in particular for the prevention or treatment of Type 2 diabetes, obesity, and high blood pressure. In certain embodiments, described herein are pharmaceutical compositions comprising crystalline (2R,3S,5R)-2-(2,5-Difluorophenyl)-5-[2-(methylsulfonyl)-2,6-dihydropyrrolo[3,4-c]pyrazol-5(4H)-yl]tetrahydro-2H-pyran-3-amine and a pharmaceutically acceptable carrier.
BRIEF DESCRIPTION OF THE FIGURES
[0006] FIG. 1 is a X-ray diffraction pattern of crystalline Form I of Compound I.
[0007] FIG. 2 is a thermogravimetric analysis (TGA) curve of crystalline Form I of Compound I.
[0008] FIG. 3 is a differential scanning calorimetry (DSC) curve of crystalline Form I of Compound I.
[0009] FIG. 4 is a solid state NMR spectra of crystalline Form I of Compound I.
[0010] FIG. 5 is an IR spectra of crystalline Form II of Compound I.
[0011] FIG. 6 is a X-ray diffraction pattern of crystalline Form II of Compound I.
[0012] FIG. 7 is a thermogravimetric analysis (TGA) curve of crystalline Form II of Compound I.
[0013] FIG. 8 is a differential scanning calorimetry (DSC) curve of crystalline Form II of Compound I.
[0014] FIG. 9 is a solid state NMR spectra of crystalline Form II of Compound I.
[0015] FIG. 10 is an IR spectra of crystalline Form II of Compound I.
[0016] FIG. 11 is a X-ray diffraction pattern of crystalline Form III of Compound I.
[0017] FIG. 12 is a thermogravimetric analysis (TGA) curve of crystalline Form III of Compound I.
[0018] FIG. 13 is a differential scanning calorimetry (DSC) curve of crystalline Form III of Compound I.
[0019] FIG. 14 is a X-ray diffraction pattern of crystalline Form IV of Compound I.
[0020] FIG. 15 is a thermogravimetric analysis (TGA) curve of crystalline Form IV of Compound I.
[0021] FIG. 16 is a differential scanning calorimetry (DSC) curve of crystalline Form IV of Compound I.
DETAILED DESCRIPTION OF THE INVENTION
[0022] This invention relates to crystalline (2R,3S,5R)-2-(2,5-Difluorophenyl)-5-[2-(methylsulfonyl)-2,6-dihydropyrrolo[3,4-c]pyrazol-5(4H)-yl]tetrahydro-2H-pyran-3-amine of Compound I:
[0000]
[0000] Unless a specific form designation is given, the term “crystalline (2R,3S,5R)-2-(2,5-Difluorophenyl)-5-[2-(methylsulfonyl)-2,6-dihydropyrrolo[3,4-c]pyrazol-5(4H)-yl]tetrahydro-2H-pyran-3-amine refers to all crystalline forms of (2R,3S,5R)-2-(2,5-Difluorophenyl)-5-[2-(methylsulfonyl)-2,6-dihydropyrrolo[3,4-c]pyrazol-5(4H)-yl]tetrahydro-2H-pyran-3-amine described herein. The crystalline forms described herein exist as the anhydrous free base of (2R,3S,5R)-2-(2,5-Difluorophenyl)-5-[2-(methylsulfonyl)-2,6-dihydropyrrolo[3,4-c]pyrazol-5(4H)-yl]tetrahydro-2H-pyran-3-amine.
[0023] One embodiment of the crystalline forms described herein is (2R,3S,5R)-2-(2,5-Difluorophenyl)-5-[2-(methylsulfonyl)-2,6-dihydropyrrolo[3,4-c]pyrazol-5(4H)-yl]tetrahydro-2H-pyran-3-amine (Form I). Form I is further described below.
[0024] Another embodiment of the crystalline forms described herein is (2R,3S,5R)-2-(2,5-Difluorophenyl)-5-[2-(methylsulfonyl)-2,6-dihydropyrrolo[3,4-c]pyrazol-5(4H)-yl]tetrahydro-2H-pyran-3-amine (Form II). Form II is further described below.
[0025] Still another embodiment of the crystalline forms described herein is (2R,3S,5R)-2-(2,5-Difluorophenyl)-5-[2-(methylsulfonyl)-2,6-dihydropyrrolo[3,4-c]pyrazol-5(4H)-yl]tetrahydro-2H-pyran-3-amine (Form III). Form III is further described below.
[0026] Yet another embodiment of the crystalline forms described herein is (2R,3S,5R)-2-(2,5-Difluorophenyl)-5-[2-(methylsulfonyl)-2,6-dihydropyrrolo[3,4-c]pyrazol-5(4H)-yl]tetrahydro-2H-pyran-3-amine (Form IV). Form IV is further described below.
[0027] A further embodiment of the present invention provides a particular drug substance that comprises at least one of the crystalline forms described herein. By “drug substance” is meant the active pharmaceutical ingredient. The amount of crystalline form in the drug substance can be quantified by the use of physical methods such as X-ray powder diffraction, solid-state fluorine-19 magic-angle spinning (MAS) nuclear magnetic resonance spectroscopy, solid-state carbon-13 cross-polarization magic-angle spinning (CPMAS) nuclear magnetic resonance spectroscopy, solid state Fourier-transform infrared spectroscopy, and Raman spectroscopy.
[0028] In a class of this embodiment, the crystalline form of the present invention is present in about 5% to about 100% by weight of the drug substance. In a second class of this embodiment, the crystalline form of the present invention is present in about 10% to about 100% by weight of the drug substance. In a third class of this embodiment, the crystalline form of the present invention is present in about 25% to about 100% by weight of the drug substance. In a fourth class of this embodiment, the crystalline form of the present invention is present in about 50% to about 100% by weight of the drug substance. In a fifth class of this embodiment, the crystalline form of the present invention is present in about 75% to about 100% by weight of the drug substance. In a sixth class of this embodiment, substantially all of the drug substance is the crystalline form of the present invention, i.e., the drug substance is substantially phase pure crystalline.
[0029] In another class of this embodiment, at least 5% by weight of the drug substance is the crystalline form of the present invention. In a yet another class of this embodiment, at least 10% by weight of the drug substance is the crystalline form of the present invention. In a still another class of this embodiment, at least 15% by weight of the drug substance is the crystalline form of the present invention. In another class of this embodiment, at least 20% by weight of the drug substance is the crystalline form of the present invention. In yet another class of this embodiment, at least 25% by weight of the drug substance is the crystalline form of the present invention. In still another class of this embodiment, at least 30% by weight of the drug substance is the crystalline form of the present invention. In another class of this embodiment, at least 35% by weight of the drug substance is the crystalline form of the present invention. In a yet another class of this embodiment, at least 40% by weight of the drug substance is the crystalline form of the present invention. In a still another class of this embodiment, at least 45% by weight of the drug substance is the crystalline form of the present invention. In another class of this embodiment, at least 50% by weight of the drug substance is the crystalline form of the present invention. In yet another class of this embodiment, at least 55% by weight of the drug substance is the crystalline form of the present invention. In still another class of this embodiment, at least 60% by weight of the drug substance is the crystalline form of the present invention. In another class of this embodiment, at least 65% by weight of the drug substance is the crystalline form of the present invention. In a yet another class of this embodiment, at least 70% by weight of the drug substance is the crystalline form of the present invention. In a still another class of this embodiment, at least 75% by weight of the drug substance is the crystalline form of the present invention. In another class of this embodiment, at least 80% by weight of the drug substance is the crystalline form of the present invention. In yet another class of this embodiment, at least 85% by weight of the drug substance is the crystalline form of the present invention. In still another class of this embodiment, at least 90% by weight of the drug substance is the crystalline form of the present invention. In another class of this embodiment, at least 95% by weight of the drug substance is the crystalline form of the present invention. In a yet another class of this embodiment, at least 100% by weight of the drug substance is the crystalline form of the present invention.
[0030] The crystalline forms of the present invention exhibit pharmaceutical advantages over the amorphous free base of Compound I as described in WO 2010/056708 in the preparation of a pharmaceutical drug product containing the pharmacologically active ingredient. In particular, the enhanced chemical and physical stability of the crystalline forms constitute advantageous properties in the preparation of solid pharmaceutical dosage forms containing the pharmacologically active ingredient.
[0031] The crystalline forms of the present invention, which exhibit long acting, potent DP-IV inhibitory properties, are particularly useful for the prevention or treatment of Type 2 diabetes, obesity, and high blood pressure.
[0032] Another aspect of the present invention provides a method for the prevention or treatment of clinical conditions for which an inhibitor of DP-IV is indicated, which method comprises administering to a patient in need of such prevention or treatment a prophylactically or therapeutically effective amount of a crystalline form of the present invention, or a hydrate thereof. Such clinical conditions include diabetes, in particular Type 2 diabetes, hyperglycemia, insulin resistance, and obesity.
[0033] The present invention also provides for the use of a crystalline form of Compound I of the present invention for the prevention or treatment in a mammal of clinical conditions for which an inhibitor of DP-IV is indicated, in particular Type 2 diabetes, hyperglycemia, insulin resistance, and obesity.
[0034] The present invention also provides for the use of a crystalline form of Compound I of the present invention for the manufacture of a medicament for the prevention or treatment in a mammal of clinical conditions for which an inhibitor of DP-IV is indicated, in particular Type 2 diabetes, hyperglycemia, insulin resistance, and obesity.
[0035] The present invention also provides pharmaceutical compositions comprising a crystalline form described herein, in association with one or more pharmaceutically acceptable carriers or excipients. In one embodiment the pharmaceutical composition comprises a therapeutically effective amount of the active pharmaceutical ingredient in admixture with pharmaceutically acceptable excipients wherein the active pharmaceutical ingredient comprises a detectable amount of a crystalline (2R,3S,5R)-2-(2,5-Difluorophenyl)-5-[2-(methylsulfonyl)-2,6-dihydropyrrolo[3,4-c]pyrazol-5(4H)-yl]tetrahydro-2H-pyran-3-amine.
[0036] In a second embodiment the pharmaceutical composition comprises a therapeutically effective amount of the active pharmaceutical ingredient in an admixture with pharmaceutically acceptable excipients wherein the active pharmaceutical ingredient comprises about 1% to about 100% by weight of crystalline (2R,3S,5R)-2-(2,5-Difluorophenyl)-5-[2-(methylsulfonyl)-2,6-dihydropyrrolo[3,4-c]pyrazol-5(4H)-yl]tetrahydro-2H-pyran-3-amine. In a class of this second embodiment, the active pharmaceutical ingredient in such compositions comprises about 5% to about 100% by weight of crystalline (2R,3S,5R)-2-(2,5-Difluorophenyl)-5-[2-(methylsulfonyl)-2,6-dihydropyrrolo[3,4-c]pyrazol-5(4H)-yl]tetrahydro-2H-pyran-3-amine. In a second class of this embodiment, the active pharmaceutical ingredient in such compositions comprises about 10% to about 100% by weight of crystalline (2R,3S,5R)-2-(2,5-Difluorophenyl)-5-[2-(methylsulfonyl)-2,6-dihydropyrrolo[3,4-c]pyrazol-5(4H)-yl]tetrahydro-2H-pyran-3-amine. In a third class of this embodiment, the active pharmaceutical ingredient in such compositions comprises about 25% to about 100% by weight of crystalline (2R,3S,5R)-2-(2,5-Difluorophenyl)-5-[2-(methylsulfonyl)-2,6-dihydropyrrolo[3,4-c]pyrazol-5(4H)-yl]tetrahydro-2H-pyran-3-amine. In a fourth class of this embodiment, the active pharmaceutical ingredient in such compositions comprises about 50% to about 100% by weight of crystalline (2R,3S,5R)-2-(2,5-Difluorophenyl)-5-[2-(methylsulfonyl)-2,6-dihydropyrrolo[3,4-c]pyrazol-5(4H)-yl]tetrahydro-2H-pyran-3-amine.
[0037] In a third embodiment the pharmaceutical composition comprises a therapeutically effective amount of the active pharmaceutical ingredient in an admixture with pharmaceutically acceptable excipients wherein the active pharmaceutical ingredient comprises at least 1% by weight of crystalline (2R,3S,5R)-2-(2,5-Difluorophenyl)-5-[2-(methylsulfonyl)-2,6-dihydropyrrolo[3,4-c]pyrazol-5(4H)-yl]tetrahydro-2H-pyran-3-amine. In a class of this second embodiment, the active pharmaceutical ingredient in such compositions comprises about 5% by weight of crystalline (2R,3S,5R)-2-(2,5-Difluorophenyl)-5-[2-(methylsulfonyl)-2,6-dihydropyrrolo[3,4-c]pyrazol-5(4H)-yl]tetrahydro-2H-pyran-3-amine. In a second class of this embodiment, the active pharmaceutical ingredient in such compositions comprises at least 10% by weight of crystalline (2R,3S,5R)-2-(2,5-Difluorophenyl)-5-[2-(methylsulfonyl)-2,6-dihydropyrrolo[3,4-c]pyrazol-5(4H)-yl]tetrahydro-2H-pyran-3-amine. In a third class of this embodiment, the active pharmaceutical ingredient in such compositions comprises at least 25% by weight of crystalline (2R,3S,5R)-2-(2,5-Difluorophenyl)-5-[2-(methylsulfonyl)-2,6-dihydropyrrolo[3,4-c]pyrazol-5(4H)-yl]tetrahydro-2H-pyran-3-amine. In a fourth class of this embodiment, the active pharmaceutical ingredient in such compositions comprises at least 50% by weight of crystalline (2R,3S,5R)-2-(2,5-Difluorophenyl)-5-[2-(methylsulfonyl)-2,6-dihydropyrrolo[3,4-c]pyrazol-5(4H)-yl]tetrahydro-2H-pyran-3-amine.
[0038] The compositions in accordance with the invention are suitably in unit dosage forms such as tablets, pills, capsules, powders, granules, sterile solutions or suspensions, metered aerosol or liquid sprays, drops, ampoules, auto-injector devices or suppositories. The compositions are intended for oral, parenteral, intranasal, sublingual, or rectal administration, or for administration by inhalation or insufflation. Formulation of the compositions according to the invention can conveniently be effected by methods known from the art, for example, as described in Remington's Pharmaceutical Sciences, 17 th ed., 1995.
[0039] The dosage regimen is selected in accordance with a variety of factors including type, species, age, weight, sex and medical condition of the patient; the severity of the condition to be treated; the route of administration; and the renal and hepatic function of the patient. An ordinarily skilled physician, veterinarian, or clinician can readily determine and prescribe the effective amount of the drug required to prevent, counter or arrest the progress of the condition.
[0040] Oral dosages of the present invention, when used for the indicated effects, will range between about 0.01 mg per kg of body weight per day (mg/kg/day) to about 100 mg/kg/day, preferably 0.01 to 10 mg/kg/day, and most preferably 0.1 to 5.0 mg/kg/day. For oral administration, the compositions are preferably provided in the form of tablets containing 0.01, 0.05, 0.1, 0.5, 1.0, 2.5, 5.0, 10.0, 15.0, 25.0, 50.0, 100 and 500 milligrams of the active ingredient for the symptomatic adjustment of the dosage to the patient to be treated. A medicament typically contains from about 0.01 mg to about 500 mg of the active ingredient, preferably, from about 1 mg to about 200 mg of active ingredient. Intravenously, the most preferred doses will range from about 0.1 to about 10 mg/kg/minute during a constant rate infusion. The crystalline forms of the present invention may be administered in a single daily dose, or the total daily dosage may be administered in divided doses of two, three or four times daily. However, (2R,3S,5R)-2-(2,5-Difluorophenyl)-5-[2-(methylsulfonyl)-2,6-dihydropyrrolo[3,4-c]pyrazol-5(4H)-yl]tetrahydro-2H-pyran-3-amine is a long acting DPP-IV inhibitor. Advantageously, the crystalline forms of the present invention may be administered in a single weekly dose.
[0041] Furthermore, the crystalline forms of the present invention can be administered in intranasal form via topical use of suitable intranasal vehicles, or via transdermal routes, using those forms of transdermal skin patches well known to those of ordinary skill in the art. To be administered in the form of a transdermal delivery system, the dosage administration will, of course, be continuous rather than intermittent throughout the dosage regimen.
[0042] In the methods of the present invention, the crystalline forms described herein can form the active pharmaceutical ingredient, and are typically administered in admixture with suitable pharmaceutical diluents, excipients or carriers (collectively referred to herein as ‘carrier’ materials) suitably selected with respect to the intended form of administration, that is, oral tablets, capsules, elixirs, syrups and the like, and consistent with conventional pharmaceutical practices.
[0043] For instance, for oral administration in the form of a tablet or capsule, the active drug component can be combined with an oral, non-toxic, pharmaceutically acceptable, inert carrier such as lactose, starch, sucrose, glucose, methyl cellulose, magnesium stearate, dicalcium phosphate, calcium sulfate, mannitol, sorbitol and the like; for oral administration in liquid form, the oral drug component can be combined with any oral, non-toxic, pharmaceutically acceptable inert carrier such as ethanol, glycerol, water and the like. Moreover, when desired or necessary, suitable binders, lubricants, disintegrating agents and coloring agents can also be incorporated into the mixture. Suitable binders include starch, gelatin, natural sugars such as glucose or beta-lactose, corn sweeteners, natural and synthetic gums such as acacia, tragacanth or sodium alginate, carboxymethylcellulose, polyethylene glycol, waxes and the like. Lubricants used in these dosage forms include sodium oleate, sodium stearate, magnesium stearate, sodium benzoate, sodium acetate, sodium chloride and the like. Disintegrators include, without limitation, starch, methyl cellulose, agar, bentonite, xanthan gum and the like.
[0044] The crystalline forms of Compound I of the present invention have been found to possess a relatively high solubility in water (about 2 mg/ml), rendering them especially amenable to the preparation of formulations, in particular intranasal and intravenous formulations, which require relatively concentrated aqueous solutions of active pharmaceutical ingredient.
[0045] In a still further aspect, the present invention provides a method for the treatment and/or prevention of clinical conditions for which a DP-IV inhibitor is indicated, which method comprises administering to a patient in need of such prevention or treatment a prophylactically or therapeutically effective amount of a crystalline form of Compound I as defined above in combination with another agent useful for the treatment of Type 2 diabetes, obesity, and high blood pressure.
[0046] Compounds described herein may exist as tautomers such as keto-enol tautomers. The individual tautomers as well as mixtures thereof are encompassed with compounds of structural formula I.
[0047] The term “% enantiomeric excess” (abbreviated “ee”) shall mean the % major enantiomer less the % minor enantiomer. Thus, a 70% enantiomeric excess corresponds to formation of 85% of one enantiomer and 15% of the other. The term “enantiomeric excess” is synonymous with the term “optical purity.”
[0048] Compound I can be made by the following methods:
Intermediate 1
[0049]
tert-Butyl [(2R,3S)-5-oxo-2-(2,5-difluorophenyl)tetrahydro-2H-pyran-3-yl]carbamate
Step A: tert-Butyl (1-[methoxy(methyl)amino]-1-oxopent-4-yn-2-yl)carbamate
[0050] To an inerted vessel was charged N,N-diphenyl glycine ethyl ester (105.45 kg, 394.5 mol), tetrabutyl ammonium bromide (14 kg, 43.4 mol), and propargyl benzenesulfonate (94.45 kg, 481 mol) followed by MTBE (750 kg). Then cesium carbonate (fine mesh grade, 390 kg, 1197 mol) was added and the reaction stirred at 50-60° C. for 1 day. The batch was then cooled to 0-5° C. and water (422 kg) was slowly added. Next, tert-butyl methyl ether (170 kg) was added and the batch concentrated to 473-578 L. Then, 462 kg HCl solution (43 kg conc. HCl in 420 kg water) was added to reach a pH=1-2 below room temperature. After 7 h of stirring, the pH was 1.5 and the organic layer was separated and discarded.
[0051] The aqueous layer was then cooled to 5-10° C. and 28% aqueous NaOH (151 kg) was added slowly until the pH was 13. Then, a solution of Boc 2 O (136 kg, 624 mol in 243 kg of tert-butyl methyl ether) was added at 5-10° C. The solution was then stirred at room temperature for 4 h (pH=8) and 17% aqueous NaOH (126 kg) was slowly added followed by more Boc 2 O solution (30.7 kg, 141 mol in 60 kg tert-butyl methyl ether). The solution was then stirred at room temperature for 4 h (pH=9) and 17% aqueous NaOH (98 kg) was slowly added (pH=13) and stirred an additional 12 h (pH-10) followed by more Boc 2 O (11 kg, 50 mol). After 4 h of stirring at room temperature, the layers were separated (retained aqueous) and the organics extracted with 3% aqueous NaOH (136 kg). The aqueous layers were combined and added to tert-butyl methyl ether (338 kg). Then, aqueous 17% HCl (362 kg) was added until pH=2. The layers were separated and the aqueous extracted with tert-butyl methyl ether (420 kg). The combined organics were washed with 10% brine (139 kg), dried with Na 2 SO 4 , filtered, and concentrated to 105-158 L. Constant volume distillation with tert-butyl methyl ether continued until KF=0.4%.
[0052] Carbonyldiimidazole (90 kg, 548 mol) was added to this solution and stirred for 2 h at room temperature. Then (MeO)MeNH 2 Cl (48 kg, 492 mol) was added and the reaction stirred for 6 h. The batch was then cooled to 0-5° C. and water (80 kg) was added. The batch was then seeded with 100 g seed and water (450 kg) was added. The slurry was stirred at 0-5° C. for 3 h and then filtered. The cake was dried under vacuum at 45-60° C. for 2 days to give tert-butyl (1-[methoxy(methyl)amino]-1-oxopent-4-yn-2-yl)carbamate.
Step B: tert-Butyl [1-(2,5-difluorophenyl)-1-oxopent-4-yn-2-yl]carbamate
[0053] An inerted vessel was charged dichloromethane (866 kg) and cooled to −20 to −10° C. Then iso-propylmagnesium chloride solution in THF (2M, 326.1 kg, 669 mol) was slowly added followed by 1-bromo-2,5-difluorobenzene (120.1 kg, 622 mol). After 2 h at this temperature, an additional charge of iso-propylmagnesium chloride in THF solution was slowly added (2M, 58.65 kg, 121 mol) and the reaction aged 1 h. Then, a drop-wise addition of a dichloromethane solution of tert-butyl (1-[methoxy(methyl)amino]-1-oxopent-4-yn-2-yl)carbamate (70.8 kg, 276 mol in 292 kg dichloromethane) was conducted over 2 h at −20 to −20° C. The mixture was then warmed to room temperature and stirred for 10 h. The reaction was then slowly reverse quenched into aqueous ammonium chloride (175.6 kg in 1550 kg of water) at 5-10° C. The solution pH was then adjusted to ˜7 by adding 68 kg of con. HCl. The layers were then separated and the aqueous extracted with dichloromethane (414 kg). The combined organics were then dried with Na 2 SO 4 , filtered, treated with activated carbon (10 kg), filtered, and concentrated to 71-141 L. A constant volume (71-141 L) vacuum distillation solvent switch to n-heptane was then performed to crystallize the product. The slurry was then cooled to 0° C. and stirred 2 h. The slurry was filtered and the cake washed with n-heptane, 2-propanol, and then water. The solids were dried under vacuum at 40-50° C. overnight to give tert-butyl [1-(2,5-difluorophenyl)-1-oxopent-4-yn-2-yl]carbamate.
Step C: tert-Butyl [(1S,2S)-1-(2,5-difluorophenyl)-1-hydroxypent-4-yn-2-yl]carbamate
[0054] To a stirred vessel under nitrogen sweep was charged tert-butyl [1-(2,5-difluorophenyl)-1-oxopent-4-yn-2-yl]carbamate (35.0 kg, 113 mol), 1,4-diazabicyclo[2.2.2]octane (38.0 kg, 339 mol), and THF (465 kg). After dissolution, chloro{[(1R,2R)-(−)-2-amino-1,2-diphenylethyl](pentafluorophenylsulfonyl)amido}-(p-cymene) ruthenium (II) (410 g, 576 mmol) was added. The vessel was vacuum sparged and back-filled with nitrogen three times. Then, formic acid (26.7 kg, 580 mol) was added and the reaction heated to 45° C. overnight.
[0055] The mixture was then concentrated under vacuum to 210-280 L and tert-butyl methyl ether was then added (210 kg). After cooling to 0-10° C., 0.4% aqueous HCl was added (52 kg) until pH=4-6. After agitation and separation of the layers, the aqueous was extracted again with tert-butyl methyl ether (87 kg). The combined organics were then washed with 4% aq. NaHCO 3 (291 kg), and then brine (216 kg). The resulting organics were dried over Na 2 SO 4 , filtered through a plug of silica, and concentrated to 70-105 L. Then, tert-butyl methyl ether (132 kg) was added, followed by further batch concentration until KF=0.1%. Next, DMF (133 kg) was added and the batch was further concentrated to 70-105 L. The resulting DMF solution was 165.6 kg containing 19.4% tert-butyl [(1S,2S)-1-(2,5-difluorophenyl)-1-hydroxypent-4-yn-2-yl]carbamate (8.1/1 diastereomeric ratio and 97.9% ee).
Step D: tert-Butyl [(1S,2R)-1-(2,5-difluorophenyl)-1-hydroxypent-4-yn-2-yl]carbamate
[0056] This compound was made by following the same method described in Intermediate 1, Step C.
Step E: tert-Butyl [(1R,2R)-1-(2,5-difluorophenyl)-1-hydroxypent-4-yn-2-yl]carbamate
[0057] This compound was made by following the same method described in Intermediate 1, Step D.
Step F: tert-Butyl [(1R,2S)-1-(2,5-difluorophenyl)-1-hydroxypent-4-yn-2-yl]carbamate
[0058] This compound was made by following the same method described in Intermediate 1, Step E.
Step G: tert-Butyl [(2R,3S)-2-(2,5-difluorophenyl)-3,4-dihydro-2H-pyran-3-yl]carbamate
[0059] To a 165.6 kg solution of tert-butyl [(1S,2S)-1-(2,5-difluorophenyl)-1-hydroxypent-4-yn-2-yl]carbamate (19.4 w/w % in DMF, 103 mol) was added DMF (70 kg), 1-hydroxypyrrolidine-2,5-dione (5.95 kg, 51 mol), tetrabutylammonium hexafluorophosphate (5.20 kg, 13 mol), and NaHCO 3 (4.50 kg, 54 mol). The resulting reaction mixture was vacuum sparged with a nitrogen back-fill three times and then stirred for 30-40 min. Then, chloro(cyclopentadienyl)bis(triphenylphosphine) ruthenium (II) (823 g, 1.13 mol) and triphenylphosphine (892 g, 3.40 mol) was added and the reaction was vacuum purged with nitrogen back-filling three times. The reaction was then heated to 75-85° C. overnight. To complete the reaction, additional chloro(cyclopentadienyl)bis(triphenylphosphine) ruthenium (II) (826 g, 1.14 mol) and triphenylphosphine (892 g, 3.40 mol) was added and the reaction heated at 75-85° C. an additional 12-16 h.
[0060] After cooling to room temperature, water (250 kg) and tert-butyl methyl ether (210 kg) was added. After agitation, the layers were separated and the resulting aqueous layer was extracted with tert-butyl methyl ether (2×150 kg). The combined organics were washed with brine (4×220 kg). The organics were then dried with Na 2 SO 4 , filtered, and concentrated. The crude was passed through a plug of silica with tert-butyl methyl ether and n-heptane. The resulting solution was then solvent switched by vacuum distillation and feeding n-heptane to a slurry of 64-128 L in n-heptane. This slurry was heated to dissolve at 90-110° C. This was then cooled over 2-3 h to 0-10° C. The slurry was then filtered and the resulting wet cake dried at 40-50° C. and vacuum to give tert-butyl [(2R,3S)-2-(2,5-difluorophenyl)-3,4-dihydro-2H-pyran-3-yl]carbamate.
Step H: tert-Butyl [(2R,3R)-2-(2,5-difluorophenyl)-3,4-dihydro-2H-pyran-3-yl]carbamate
[0061] This compound was made by following the same method described in Intermediate 1, Step G.
Step I: tert-Butyl [(2S,3S)-2-(2,5-difluorophenyl)-3,4-dihydro-2H-pyran-3-yl]carbamate
[0062] This compound was made by following the same method described in Intermediate 1, Step H.
Step J: tert-Butyl [(2S,3R)-2-(2,5-difluorophenyl)-3,4-dihydro-2H-pyran-3-yl]carbamate
[0063] This compound was made by following the same method described in Intermediate 1, Step I.
Step K: tert-Butyl [(2R,3S)-2-(2,5-difluorophenyl)-5-hydroxytetrahydro-2H-pyran-3-yl]carbamate
[0064] To 64.0 kg (206 mol) of tert-butyl [(2R,3S)-2-(2,5-difluorophenyl)-3,4-dihydro-2H-pyran-3-yl]carbamate in a stirred vessel was added tert-butyl methyl ether (500 kg). After dissolving, the solution was cooled to 0-5° C. and 10M borane-dimethyl sulfide complex solution was added (39 kg, 515 mol). After 1-3 h of stirring at this temperature, water (35 kg) was slowly added and the solution stirred for 2 h at 0-10° C. Then, 3% aqueous NaHCO3 (900 kg) and 1% aqueous NaOH (582 kg) was added. Next, NaBO 3 .4H 2 O (115.6 kg, 751 mol) was added portion-wise over 1 h at 0-10° C. After stirring the reaction overnight at room temperature, additional NaBO 3 .4H 2 O (25.7 kg, 167 mol) was added portion-wise over 1 h at 0-10° C. The reaction was then stirred an additional 6 h at room temperature.
[0065] The reaction was then extracted with ethyl acetate (230 kg) and the resulting organics washed with 3% aqueous NaHCO 3 (500 kg), followed by brine (376 kg). The combined aqueous layers were further extracted with ethyl acetate (2×325 kg). The organics were then treated with activated carbon (14.4 kg) for 2 h at 50-60° C. After filtration, the organics were then concentrated and solvent switched to n-heptane to form a crystalline slurry. This slurry was then filtered and the cake was washed with n-heptane. This wet cake was then dissolved in ethyl acetate (99 kg) at 50-60° C. n-Heptane (251 kg) was then added and the batch cooled to 0° C. The resulting slurry was then filtered and the cake washed with n-heptane. The solids were then dried at 40-50° C. under vacuum to give tert-butyl [(2R,3S)-2-(2,5-difluorophenyl)-5-hydroxytetrahydro-2H-pyran-3-yl]carbamate.
Step L: tert-Butyl [(2R,3R)-2-(2,5-difluorophenyl)-5-hydroxytetrahydro-2H-pyran-3-yl]carbamate
[0066] This compound was made by following the same method described in Intermediate 1, Step K.
Step M: tert-Butyl [(2S,3R)-2-(2,5-difluorophenyl)-5-hydroxytetrahydro-2H-pyran-3-yl]carbamate
[0067] This compound was made by following the same method described in Intermediate 1, Step L.
Step N: tent-Butyl [(2S,3S)-2-(2,5-difluorophenyl)-5-hydroxytetrahydro-2H-pyran-3-yl]carbamate
[0068] This compound was made by following the same method described in Intermediate 1, Step M.
Step O: tert-Butyl [(2R,3S)-2-(2,5-difluorophenyl)-5-oxotetrahydro-2H-pyran-3-yl]carbamate
[0069] To 46.8 kg (142 mol) of tert-butyl [(2R,3S)-2-(2,5-difluorophenyl)-5-hydroxytetrahydro-2H-pyran-3-yl]carbamate in a stirred vessel was added acetonitrile (150 kg), acetic acid (50 kg), and water (25 kg). After dissolving at room temperature, the solution was cooled to 0° C. and RuCl 3 .3H 2 O (250 g, 956 mmol) in water (50 kg) was added under nitrogen. Then, NaBrO 3 (11.7 kg, 77.5 mol) was added in six portions every 1.5 h under nitrogen. After stirring at 0° C. for 6 h, 2-propanol (31 kg) was added over 30 min. at 0° C. Then, water (720 kg) was added at this temperature over 5 h. The resulting slurry was stirred overnight, filtered, and cake washed with water. The solids were then dried under vacuum at 40-60° C. to give tert-butyl [(2R,3S)-2-(2,5-difluorophenyl)-5-oxotetrahydro-2H-pyran-3-yl]carbamate.
Intermediate 2
[0070]
2-(methylsulfonyl)-2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazol-5-ium benzenesulfonate
Step A: tert-Butyl (3Z)-3-[(dimethylamino)methylene]-4-oxopyrrolidine-1-carboxylate
[0071] A solution of tert-butyl 3-oxopyrrolidine-1-carboxylate (53.4 kg, 288 mol) in THF (133 kg) was treated with DMF-DMA (103 kg, 864 mol) in THF (472 kg) and heated at 65-70° C. under nitrogen for 20 h. The solution was cooled, evaporated under reduced pressure and solvent switched under distillation to cyclohexane. The resulting slurry was then filtered, cake washed with cyclohexane, and then water. The solids were then dried under vacuum at 35-40° C. to give tert-butyl (3Z)-3-[(dimethylamino)methylene]-4-oxopyrrolidine-1-carboxylate.
Step B: tert-Butyl 6a-hydroxy-3a,4,6,6a-tetrahydropyrrol[3,4-c]pyrazole-5(1H)-carboxylate
[0072] To a solution of tert-butyl (3Z)-3-[(dimethylamino)methylene]-4-oxopyrrolidine-1-carboxylate (58.2 kg, 242 mol) in toluene (251 kg) at 35-45° C. was added hydrazine hydrate (14.6 kg, 290 mol) via drop-wise addition over 2 h. The mixture was then stirred for 10 h at this temperature. The batch was then cooled to 0-10° C. and the slurry stirred for 6 h. This slurry was then filtered and the cake washed with n-heptane. The solids were then dried under vacuum overnight at 35-50° C. to give tert-butyl 6a-hydroxy-3a,4,6,6a-tetrahydropyrrol[3,4-c]pyrazole-5(1H)-carboxylate.
Step C: tert-Butyl 4,6-dihydropyrrolo[3,4-c]pyrazole-5(1H)-carboxylate
[0073] To a solution of tert-butyl 6a-hydroxy-3a,4,6,6a-tetrahydropyrrol[3,4-c]pyrazole-5(1H)-carboxylate (47.0 kg, 207 mol) in dichloromethane (669 kg) at 0° C. was added a methanol solution of toluene-4-sulfonic acid monohydrate (3.7 kg, 20 mol in 38 kg MeOH) drop-wise over 2 h. The reaction was then aged for 4 h at this temperature. Then, 5% aqueous NaHCO 3 (91 kg) was added and stirred at room temperature for 30 min. The layers were then separated and the aqueous extracted with dichloromethane (312 kg). The combined organics were washed with 5% brine (190 kg then 483 kg), treated with activated carbon (2.7 kg) and filtered. The resulting organics were dried with Na 2 SO 4 , filtered, and concentrated to 71-118 L. n-Heptane was then added (238 kg) and the batch further concentrated to 188-235 L. The slurry was cooled to 10-20° C., filtered, and the cake washed with n-heptane. The solids were dried under vacuum at 40-50° C. overnight to give tert-butyl 4,6-dihydropyrrolo[3,4-c]pyrazole-5(1H)-carboxylate.
Step D: tert-Butyl 2-(methylsulfonyl)-2,6-dihydropyrrolo[3,4-c]pyrazole-5(4H)-carboxylate
[0074] A solution of tert-butyl 4,6-dihydropyrrolo[3,4-c]pyrazole-5(1H)-carboxylate (30.0 kg, 143 mol) in 2-methyltetrahydrofuran (384 mg) was vacuum purged with nitrogen back-fill three times. The, triethylamine (25.0 kg, 247 mol) was added and the batch cooled to −10-5° C. Then, methanesulfonyl chloride (21.4 kg, 187 mol) was slowly added over 2 h. After stirring for 1 h at room temperature, water (150 kg) was added drop-wise at 5-15° C. This was followed by addition of 1N HCl solution until the pH was 7. The resulting layers were separated and the aqueous extracted with 2-methyltetrahydrofuran (106 kg). The combined organics were washed with saturated brine (2×150 kg), dried with Na 2 SO 4 , filtered, and concentrated to 60-90 L.
[0075] The resulting crude was dissolved in 2-methyltetrahydrofuran (381 kg) and charged with a solution of potassium tert-butoxide in THF (805 g in 6.6 kg THF). After stirring 1 h at room temperature under nitrogen, more potassium tert-butoxide in THF (329 g in 3.0 kg THF) was added and stirred for 1 h. Analytical analysis indicates that tert-butyl 2-(methylsulfonyl)-2,6-dihydropyrrolo[3,4-c]pyrazole-5(4H)-carboxylate is the major regioisomer, so saturated brine (154 kg) was then added. After brief agitation, the layers are separated and the organics are washed with saturated brine (2×155 kg). The combined aqueous waste layers were then extracted with 2-methyltetrahydrofuran (103 kg). The combined organics were treated with activated carbon (8.75 kg), filtered, and dried with Na 2 SO 4 . This was then filtered and concentrated to 60-90 L. This slurry was then heated to dissolve solids at 40-50° C. and n-heptane was added (34 kg). After cooling to room temperature for 2-4 h, n-heptane (156 kg) was added and the slurry was then aged for 2-4 h at 0-5° C. The slurry was filtered and the cake washed with n-heptane. The solids were dried under vacuum at 45-55° C. to give tert-butyl 2-(methylsulfonyl)-2,6-dihydropyrrolo[3,4-c]pyrazole-5(4H)-carboxylate.
Step E: tert-Butyl 1-(methylsulfonyl)-4,6-dihydropyrrolo[3,4-c]pyrazole-5(1H)-carboxylate
[0076] This compound was made by following the same method described in Intermediate 1, Step D.
Step F: 2-(methylsulfonyl)-2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazol-5-ium benzenesulfonate
[0077] To a solution of tert-butyl 2-(methylsulfonyl)-2,6-dihydropyrrolo[3,4-c]pyrazole-5(4H)-carboxylate (32.1 kg, 111 mol) in iso-propylacetate (289 kg) was added benzenesulfonic acid (35.35 kg, 223 mol). The reaction was stirred for 3 days at room temperature and then cooled to 0-10° C. and stirred an additional 1 h. The resulting slurry was filtered and the cake washed with iso-propylacetate. The solids were dried overnight under vacuum at room temperature to give 2-(methylsulfonyl)-2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazol-5-ium benzenesulfonate.
(2R,3S,5R)-2-(2,5-Difluorophenyl)-5-[2-(methylsulfonyl)-2,6-dihydropyrrolo[3,4-c]pyrazol-5(4H)-yl]tetrahydro-2H-pyran-3-amine
[0078]
Step A: tert-Butyl {(2R,3S,5R)-2-(2,5-difluorophenyl)-5-[2-(methylsulfonyl)-2,6-dihydropyrrolo[3,4-c]pyrazol-5(4H)-yl]tetrahydro-2H-pyran-3-yl}carbamate
[0079] A vessel was charged with N,N-dimethylacetamide (520.6 kg), 2-(methylsulfonyl)-2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazol-5-ium benzenesulfonate (intermediate 2, 30.0 kg, 86.8 mol), and tert-butyl [(2R,3S)-2-(2,5-difluorophenyl)-5-oxotetrahydro-2H-pyran-3-yl]carbamate (intermediate 1, 31.2 kg, 95.3 mol). After dissolving at room temperature, the solution was cooled to 0-10° C. and sodium triacetoxyborohydride (24 kg, 113 mol) was added in four equal portions every 40 min. The reaction was then allowed to warm to room temperature and stirred an additional 5 h. The solution was then cooled to 5-15° C. and water (672 kg) was added over 1-2 h. The resulting slurry was filtered and the cake washed sequentially with N,N-dimethylacetamide, twice with water, and then n-heptane. The solids were dried under vacuum at 40-60° C. to give tert-butyl {(2R,3S,5R)-2-(2,5-difluorophenyl)-5-[2-(methylsulfonyl)-2,6-dihydropyrrolo[3,4-c]pyrazol-5(4H)-yl]tetrahydro-2H-pyran-3-yl}carbamate.
Step B: (2R,3S,5R)-2-(2,5-Difluorophenyl)-5-[2-(methylsulfonyl)-2,6-dihydropyrrolo[3,4-c]pyrazol-5(4H)-yl]tetrahydro-2H-pyran-3-amine
[0080] Benzenesulfonic acid (32.95 kg, 271 mol) was dissolved in dichloromethane (1020 kg) under nitrogen. Then, 880 g of water was added such that the solution KF was 0.2%. Next, tert-butyl {(2R,3S,5R)-2-(2,5-difluorophenyl)-5-[2-(methylsulfonyl)-2,6-dihydropyrrolo[3,4-c]pyrazol-5(4H)-yl]tetrahydro-2H-pyran-3-yl}carbamate (38.4 kg, 100 mol) was added in three equal portions over 30 min. The reaction was then aged overnight at room temperature. Next, water (733 kg) was added over 1 h and the reaction stirred rapidly for 1 h. The layers were then separated, discarding the resulting organics layer. To the aqueous layer was charged dichloromethane (510 kg) followed by triethylamine (22.4 kg, 592 mol). After agitation, the layers were separated and the aqueous extracted with dichloromethane (510 kg). The combined organics were washed with 7% aqueous NaHCO 3 (2×410 kg) and 5% brine (386 kg). The organics were then dried with Na 2 SO 4 , filtered, and treated with activated carbon (6.2 kg of C-941). The carbon was filtered off and the filtrate was concentrated under vacuum to 154-193 L. This solution was then warmed to 30-35° C. to dissolve solids (additional dichloromethane may be added to dissolve solids). Next, iso-propylacetate (338 kg) was added and the solution stirred at room temperature for 1.5 h. Then, n-heptane (159 kg) was charged to the vessel drop-wise and stirred for 3 h. The slurry was then filtered and the cake washed with n-heptane. This wet cake was then recrystallized again by dissolving it into dichloromethane and adding iso-propylacetate and n-heptane as before, filtering, and washing with n-heptane. The solids were dried under vacuum at 40-50° C. overnight to give crystalline (2R,3S,5R)-2-(2,5-Difluorophenyl)-5[2-(methylsulfonyl)-2,6-dihydropyrrolo[3,4-c]pyrazol-5(4H)-yl]tetrahydro-2H-pyran-3-amine was washed with cold 2:1EtOAc/hexanes to give the title compound as an off-white solid. 1 H NMR (500 MHz, CD 3 OD): 1.71 (q, 1H, J=12 Hz), 2.56-2.61 (m, 1H), 3.11-3.18 (m, 1H), 3.36-3.40 (m, 1H), 3.48 (t, 1H, J=12 Hz), 3.88-3.94 (m, 4H), 4.30-4.35 (m, 1H), 4.53 (d, 1H, J=12 Hz), 7.14-7.23 (m, 2H), 7.26-7.30 (m, 1H), 7.88 (s, 1H). LC-MS: 399.04 [M+1].
Form I
[0081] Form I was produced by direct crystallization of the amorphous free base of Compound I in ethyl acetate. The characterization results for XRPD, ssNMR, DSC, TGA and IR are shown below.
Form II
[0082] Crystalline Form II was produced by re-crystallization of Form I in isopropyl acetate and heptane 1:1 at room temperature. Form II was characterized using XRPD, ssNMR, DSC, TGA and IR. Conversion of Form II into Form I is slow but observed in all turnover experiments with 50-50 seed including DCM-Heptane 25° C. over two days, IPAc 25° C. 17 hr, IPAc 60° C. for one day, H 2 O 60° C. over two weeks, three days, NMP-water 1-1 35° C. over three days. The relationship between Form I and Form II is enantiotropic having Form I as the most stable phase above 13° C.
Form III
[0083] Form III was produced by dissolving Form I in MeOH and evaporating the solvent, followed by heating to 140° C. and isothermal for 10 min. This phase is metastable to Form I and II and its characterization was limited to the amount of sample available. Form III was analyzed by XRPD and DSC.
Form IV
[0084] Form IV was produced by dissolving Form I in 1:1 THF-water and evaporating the solvent. Anhydrous Form IV is metastable to Form I and II and therefore the characterization was limited to the amount of sample available. Form IV was analyzed using XRPD, DSC and TGA.
X-Ray Powder Diffraction
[0085] X-ray powder diffraction studies are widely used to characterize molecular structures, crystallinity, and polymorphism. The X-ray powder diffraction patterns for the solid phases for crystalline forms of Compound I were generated on a Philips Analytical X′Pert PRO X-ray Diffraction System with PW3040/60 console. A PW3373/00 ceramic Cu LEF X-ray tube K-Alpha radiation was used as the source. The diffraction peak positions were referenced by silicon (internal standard) which has a 2 theta value of 28.443 degree. The experiments were analyzed at ambient condition.
[0086] The crystalline forms described herein have a phase purity of at least about 5% of the form with the above X-ray powder diffraction and DSC physical characteristics. In one embodiment the phase purity is at least about 10% of the form with the above solid-state physical characteristics. In a second embodiment the phase purity is at least about 25% of the form with the above solid-state physical characteristics. In a third embodiment the phase purity is at least about 50% of the form with the above solid-state physical characteristics. In a fourth embodiment the phase purity is at least about 75% of the form with the above solid-state physical characteristics. In a fifth embodiment the phase purity is at least about 90% of the form with the above solid-state physical characteristics. In a sixth embodiment the crystalline forms of the present invention are the substantially phase pure forms with the above solid-state physical characteristics. By the term “phase purity” is meant the solid state purity of the particular form with regard to a particular crystalline form as determined by the solid-state physical methods described in the present application.
[0087] FIG. 1 is the X-ray powder diffraction (XRPD) pattern for Form I of Compound I with selected d-spacings listed in Table 1.
[0000]
TABLE 1
XRPD: Form I of Compound I
2θ(2 theta)(degrees)
d-spacing (Å)
10.3
8.63
12.7
6.99
14.6
6.07
16.1
5.51
17.8
4.97
19.2
4.61
22.2
4.01
24.1
3.70
26.9
3.31
[0088] Crystalline (2R,3S,5R)-2-(2,5-Difluorophenyl)-5-[2-(methylsulfonyl)-2,6-dihydropyrrolo[3,4-c]pyrazol-5(4H)-yl]tetrahydro-2H-pyran-3-amine (Form I) is characterized by having at least four peaks in its powder X-ray diffraction pattern selected from the group consisting of 10.3±0.1 2θ, 12.7±0.1 2θ, 14.6±0.1 2θ, 16.1±0.1 2θ, 17.8±0.1 2θ, 19.2+0.1 2θ, 22.2+0.1 2θ, 24.1±0.1 2θ and 26.9±0.1 2θ. The crystalline Form 1 can be characterized by the following four peaks in its powder X-ray diffraction pattern 17.8±0.12θ, 19.2±0.1 2θ, 22.2±0.1 2θ and 24.1±0.1 2θ. The crystalline Form 1 can be characterized by the following four peaks in its powder X-ray diffraction pattern of FIG. 3 .
[0089] FIG. 6 is the X-ray powder diffraction (XRPD) pattern for Form II of Compound I with selected d-spacings listed in Table 2.
[0000]
TABLE 2
X-ray powder diffraction: Form II of Compound I
2θ(2 theta)(degrees)
d-spacing (Å)
7.5
11.81
15.0
5.91
16.2
5.49
20.9
4.25
22.0
4.04
27.0
3.30
27.6
3.24
33.3
2.69
[0090] Crystalline (2R,3S,5R)-2-(2,5-Difluorophenyl)-5-[2-(methylsulfonyl)-2,6-dihydropyrrolo[3,4-c]pyrazol-5(4H)-yl]tetrahydro-2H-pyran-3-amine (Form II) can be characterized by having at least four peaks in its powder X-ray diffraction pattern selected from the group consisting of 7.5±0.1 2θ, 15.0±0.12 0, 16.2±0.1 2θ, 20.9±0.1 2θ, 22.0±0.1 2θ, 27.0±0.1 2θ, 27.6±0.1 2θ, 33.3±0.1 2θ. The crystalline Form II can be characterized by the following four peaks in its powder X-ray diffraction pattern 20.9±0.1 2θ, 22.0±0.1 2θ, 27.0±0.1 2θ and 27.6±0.1 2θ. Crystalline Form II of can be characterized by the X-ray powder diffraction pattern of FIG. 6 .
[0091] FIG. 11 is the X-ray powder diffraction (XRPD) pattern for Form III of Compound I with selected d-spacings listed in Table 3.
[0000]
TABLE 3
X-ray powder diffraction: Form III of Compound I
2θ(2 theta)(degrees)
d-spacing (Å)
14.5
6.09
15.9
5.58
17.3
5.11
18.7
4.76
19.5
4.56
21.2
4.19
22.0
4.05
23.2
3.83
[0092] Crystalline (2R,3S,5R)-2-(2,5-Difluorophenyl)-5-[2-(methylsulfonyl)-2,6-dihydropyrrolo[3,4-c]pyrazol-5(4H)-yl]tetrahydro-2H-pyran-3-amine (Form III) can be characterized by having at least four peaks in its powder X-ray diffraction pattern selected from the group consisting of 14.5±0.1 2θ, 15.9±0.1 2θ, 17.3±0.1 2θ, 18.7±0.1 20, 19.5±0.1 2θ, 19.5±0.1 2θ, 21.2±0.1 2θ, 22.0±0.1 2θ and 23.2±0.1 2θ. Crystalline Form III can be characterized by the following four peaks in its powder X-ray diffraction pattern 19.5±0.1 2θ, 21.2±0.1 2θ, 22.0±0.1 2θ and 23.2±0.1 2θ. Crystalline Form III can be characterized by the X-ray powder diffraction pattern of FIG. 11 .
[0093] FIG. 14 is the X-ray powder diffraction (XRPD) pattern for Form IV of Compound I with selected d-spacings listed in Table 4.
[0000]
TABLE 4
X-ray powder diffraction: anhydrous Form IV of Compound I
2θ(2 theta)(degrees)
d-spacing (Å)
8.1
10.98
10.6
8.33
16.0
5.55
16.9
5.24
19.5
4.56
21.3
4.18
23.3
3.82
[0094] Crystalline (2R,3S,5R)-2-(2,5-Difluorophenyl)-5-[2-(methylsulfonyl)-2,6-dihydropyrrolo[3,4-c]pyrazol-5(4H)-yl]tetrahydro-2H-pyran-3-amine (Form IV) can be characterized by having at least four peaks in its powder X-ray diffraction pattern selected from the group consisting of 8.1±0.1 2θ, 10.6±0.1 2θ, 16.0±0.1 2θ, 16.9±0.1 2θ, 19.5±0.1 2θ, 21.3±0.1 2θ, 23.3+0.1 2θ and 25.4+0.1 2θ. Crystalline Form IV can be characterized by the following four peaks in its powder X-ray diffraction pattern 16.9±0.1 2θ, 19.5±0.1 2θ, 21.3+0.1 2θ and 23.3±0.1 2θ. Crystalline Form IV can be characterized by the X-ray powder diffraction pattern of FIG. 14 .
[0000] ssNMR Spectra
[0095] Solid-state carbon-13 nuclear magnetic resonance spectrum was recorded on a Bruker AV400 NMR spectrometer using a Bruker 4 mm H/F/X BB double resonance CPMAS probe. The spectrum were collected utilizing proton/carbon-13 variable-amplitude cross-polarization (VACP) at 10 kHz, with a contact time of 3 ms. Other experimental parameters used for data acquisition were a proton 90-degree pulse of 100 kHz, SPINAL64 decoupling at 100 kHz, a pulse delay of 5 s, and signal averaging for 1024 scans. The magic-angle spinning (MAS) rate was set to 10 kHz. A Lorentzian line broadening of 10 Hz was applied to the spectrum before Fourier Transformation. Chemical shifts are reported on the TMS scale using the carbonyl carbon of glycine (176.70 ppm.) as a secondary reference.
[0096] Crystalline Form I can further characterized by the nuclear magnetic resonance (NMR) spectra of FIG. 4 . FIG. 4 is the ssNMR spectra for Form I of Compound I with selected peaks listed in Table 5.
[0000]
TABLE 5
Selected ssNMR peaks for Form I of Compound I
Peak (ppm)
Relative Intensity
124.3
100
42.6
91
119.0
67
48.6
56
128.9
53
90.1
50
73.2
46
163.6
44
59.9
42
157.9
38
[0097] Crystalline Form II can be further characterized by the nuclear magnetic resonance (NMR) spectra of FIG. 9 . FIG. 9 is the ssNMR spectra for Form II of Compound I with selected peaks listed in Table 6.
[0000]
TABLE 6
Selected ssNMR peaks for Form II of Compound I
Peak (ppm)
Relative Intensity
116.9
100
127.5
82
42.2
78
132.1
61
73.5
60
79.0
59
62.3
57
165.3
57
53.0
56
56.3
56
IR Spectra
[0098] The Infrared spectrum was obtained using Attenuated Total Reflectance (ATR). The sample was placed directly onto the ATR-FTIR sampling device and the infrared spectrum was recorded using a Nicolet Nexus 670 FTIR spectrometer.
[0099] FIG. 5 is an IR spectra of Form I of Compound I. Crystalline Form I can be further characterized by the IR spectra of FIG. 5 .
[0100] FIG. 10 is an IR spectra of Form II of Compound I. Crystalline Form II can be further characterized by the IR spectra of FIG. 10 .
[0101] In addition to the X-ray powder diffraction patterns described above, the crystalline forms of Compound I of the present invention were further characterized by means of their differential scanning calorimetry (DSC) curves and their thermogravimetric analysis (TGA) curves.
DSC
[0102] Differential Scanning calorimetry data were acquired using TA Instruments DSC 2910 or DSC2000. Between 2 and 6 mg sample was weighed into a pan and covered. This pan was then covered and placed at the sample position in the calorimeter cell. An empty pan is placed at the reference position. The calorimeter cell is closed and a flow of nitrogen is passed through the cell. The heating program is set to heat the sample at a heating rate of 10° C./min to a temperature of approximately 250° C. The data was analyzed using Universal Analysis 2000 Version 3.9A. The thermal events were integrated between baseline temperature points that are above and below the temperature range over which the thermal event is observed. The data reported are the onset temperature, peak temperature and enthalpy.
[0103] Crystalline Form I can be further characterized by the differential scanning calorimetric (DSC) curve of FIG. 3 . Crystalline Form II can be further characterized by the differential scanning calorimetric (DSC) curve of FIG. 8 . Crystalline Form III can be further characterized by the differential scanning calorimetric (DSC) curve of FIG. 13 . Crystalline Form IV can be further characterized by the differential scanning calorimetric (DSC) curve of FIG. 16 .
TGA
[0104] Thermogravimetric data was acquired using a Perkin Elmer model TGA 7. Experiments were performed under a flow of nitrogen and using a heating rate of 10° C./min to a maximum temperature of approximately 250° C. After automatically taring the balance, 5 to 20 mg of sample was added to the platinum pan, the furnace was raised, and the heating program started. Weight/temperature data are collected automatically by the instrument. Analyses of the results were carried out by selecting the Delta Y function within the instrument software and choosing the temperatures between which the weight loss is to be calculated. Weight losses are reported up to the onset of decomposition/evaporation. Crystalline Form I can be further characterized by the thermogravimetric analysis (TGA) curve of FIG. 2 . Crystalline Form II can be further characterized by the thermogravimetric analysis (TGA) curve of FIG. 7 . Crystalline Form III can be further characterized by the thermogravimetric analysis (TGA) curve of FIG. 12 . Crystalline Form IV can be further characterized by the thermogravimetric analysis (TGA) curve of FIG. 15 .
[0105] A representative sample of Form I was analyzed by DSC and TGA according to the methods described above. Form I displays one endotherm (melting of Form I confirmed by hot stage microscopy) with Tonset=173.48° C., Tpeak=175.32° C., and ΔH=82.28 J/g ( FIG. 3 ). Thermogravimetric analysis exhibits insignificant weight loss between room temperature and melting point of Form I ( FIG. 2 ).
[0106] A representative sample of Form II was analyzed by DSC ( FIG. 8 ) and TGA ( FIG. 7 ) according to the methods described above. The first endotherm in the DSC curve is associated with the melting of Form II with T onset =144.75° C., T peak =147.59° C., and ΔH=23.41 J/g ( FIG. 11 ). The first endotherm is followed by a recrystallization event to produce Form I at ˜150° C. and finally by the melting of form I at T onset =170.18° C., T peak =172.95° C., and ΔH=57.45 J/g. TG analysis exhibits minimum weight loss (trapped solvent) between room temperature and melting of Form I.
[0107] DSC of Form III ( FIG. 13 ) displays one endotherm associated with the melting of Form III with Tonset=164.30° C., Tpeak=169.38° C., and ΔH=23.41 J/g. Thermogravimetric analysis ( FIG. 12 ) shows ˜1% w/w residual solvent in the initial material which was removed by heating at 140 C and holding for 10 min.
[0108] DSC of Form IV ( FIG. 16 ) displays one endotherm associated with the melting of Form IV with Tonset=171.25° C., Tpeak=172.30° C., and ΔH=84.64 J/g. Less than 1% weight loss is observed up to melting using TGA ( FIG. 15 ). | Novel crystalline forms of (2R,3S,5R)-2-(2,5-Difluorophenyl)-5-[2-(methylsulfonyl)-2,6-dihydropyrrolo[3,4-c]pyrazol-5(4H)-yl]tetrahydro-2H-pyran-3-amine are potent inhibitors of dipeptidyl peptidase-IV and are useful for the treatment of non-insulin dependent (Type 2) diabetes mellitus. The invention also relates to pharmaceutical compositions containing these novel forms, processes to prepare these forms and their pharmaceutical compositions as well as uses thereof for the treatment of Type 2 diabetes. | 8 |
BACKGROUND OF THE INVENTION
Membrane roofs are roofs that are covered with a polymeric sheet or membrane. These polymeric sheets can be, for example, polyvinyl chloride (PVC), thermoplastic olefin (TPO), or ethylene propylene diene monomer rubber (EPDM), as well as many others. The polymeric sheet is positioned over a roof surface and held in place by fasteners, adhesive, or ballast. Adjacent sheets are bonded together along lap seams to form a unitary single sheet of the polymer covering the entire roof.
Generally, the roofing membrane is either white or black. Theoretically, the membranes could be basically any color.
One chooses a white membrane roof for either aesthetic purposes or to reduce energy costs by reflecting thermal energy. In either event, it is important that the white membrane roof sheeting be clean, i.e., white, subsequent to installation or it will not provide the aesthetic appearance desired nor have the same reflective properties.
Particularly, when replacing an existing roof, it is difficult to keep the new sheeting clean. In a re-roofing application, a section of the old roof covering is removed and new roof membrane is immediately installed in its place. This allows the roof to be fully covered each night. As subsequent sections of the old roof are removed, the roofers walk on the previously installed new membrane. This can scratch and mar the new membrane. Even when installing a new roof, it is difficult to keep the white membrane clean during installation.
SUMMARY OF THE INVENTION
The present invention is premised on the realization that during installation of a single-ply roofing membrane, the surface of the membrane can be protected from dirt, scratches and scrapes by providing a removable tinted or colored release liner adhered to the membrane. The release liner is left in place during installation of the white membrane roof sheeting and be removed after completion of the installation. The tinting or coloration on the release liner ensures that the release sheet is noticeable and not inadvertently left on the roof. Further, the release liner can be formed from an environmentally degradable polymer so that even if some portions of the release sheet remain on the roof, they will degrade quickly and basically wash off the roof.
The objects and advantages of the present invention will be further appreciated in light of the following detailed description and drawings in which:
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a perspective view of the present invention;
FIG. 2 is a cross sectional view taken at lines 2 - 2 of FIG. 1 ;
FIG. 3 is a cross sectional view of an alternate embodiment of the present invention;
FIG. 4 is a perspective view of the present invention during installation;
FIG. 5 is a cross sectional view of an edge portion of the present invention during installation and prior to removal of the release sheet.
FIG. 6 is a perspective view of an alternate embodiment of the present invention;
FIG. 7 is a cross sectional view broken away taken at line 7 - 7 of FIG. 6 .
FIG. 8 is a cross sectional view partially broken away of a second alternate embodiment of the present invention;
FIG. 9 is a perspective view of a third alternate embodiment of the present invention.
DETAILED DESCRIPTION
The present invention is a roof laminate 10 that includes a roof membrane 12 and a release sheet or protective sheet 14 . The roof membrane 10 includes a first surface 16 and a second surface 18 , and, likewise, the release sheet 14 includes a first surface 20 and a second surface 22 which rests on and covers the first surface 16 of membrane 12 .
Membrane 12 can be formed from any polymer typically used in roofing applications. These include polyvinyl chloride, thermoplastic olefin, ethylene propylene diene monomer rubber polyethylene polyolefin, as well as others. The membrane can have a bottom fibrous surface referred to as fleeceback, which improves bond strength in a fully adhered system. The membrane 12 is preferably white or slightly off-white. It can be any color. The present invention is most useful when the membrane is a lighter color, such as white or off-white, and is least advantageous when the membrane is black. Although theoretically one may want to incorporate a protective covering over a black sheeting for use in the present invention.
Membrane 12 can be any typical size. These can be as narrow as 5 feet and as wide as 40 feet. Length can be 50-100 feet or more. Membrane 12 has a thickness effective for use in a membrane roof system. Generally, these will be 20 to about 160 mils thick. Roofing membranes are water insoluble and designed to withstand environmental conditions for at least 15 to 20 years.
The protective sheet 14 is a thin polymeric sheet which can be formed from a variety of different polymers. Although the protective sheet can be clear, it is preferable that it be tinted with a color that is distinguishable from the color of the membrane 12 . Thus, if the membrane 12 is white, the protective sheet 14 is preferably any color other than clear or white, such as green, red blue or yellow.
Preferably, the protective sheet 14 is formed from an environmentally degradable polymer. Exemplary environmentally degradable polymers include polyhydroxyalkanoates such as those disclosed in U.S. Pat. No. 5,070,122, polylactic acid and copolymers of polylactic acid and ethylene carbonmonoxide copolymers as disclosed in U.S. Pat. No. 5,135,966. These polymers break down over a period of time, preferably less than a month when exposed to certain environmental conditions, such as sunlight, heat or moisture, or a combination of any of these. Preferably, these environmentally degradable membranes will break down in a matter of days.
The roofing laminate 10 is formed by separately forming the roofing membrane 12 and the protective sheet 14 , and laminating the two together. If the protective sheet 14 includes an adhesive layer, this can be formed by co-extruding a pressure sensitive adhesive along with the membrane, or subsequently coating the formed membrane with a pressure sensitive adhesive, in particular a thermoplastic pressure sensitive adhesive. The protective sheet can also be made naturally adherent to the membrane by incorporating tackifiers into the protective sheet and applying the protective sheet to the membrane in a slightly stretched condition which liberates tackifier. The exposed tackifier provides weak adhesion of the protective sheet to the membrane. Once the protective sheet 14 is laminated to the membrane, the laminate 10 is formed into a roll 24 .
Alternately, as shown in FIG. 3 , a thin layer of adhesive 25 may be applied between the first surface of the membrane 12 and second surface of the protective sheet 14 to adhere the two together. The adhesive should be clear and have a preferable adherence to the protective sheet 14 as opposed to the membrane 12 . A water soluble adhesive is preferred so that if any remains on the membrane 12 after removing the protective sheet it will wash away.
To apply the membrane 12 over a roof surface 30 , two adjacent sheets 32 and 34 of the roofing laminate 10 are laid down side by side over the roof surface 30 . The membrane 12 of laminate 32 is fixed to the roof, generally using adhesives (not shown). However, other methods such as mechanically fastening the membrane to the roof can be employed. Second sheet 34 of roofing laminate 10 is rolled out and adhered to the roof surface adjacent the first sheet 32 with edge 36 of the second sheet 34 overlapping edge 38 of the first sheet 32 . The overlapping edges 36 and 38 are adhered or welded to each other.
With the embodiment shown in FIG. 1 , the edge portion 40 of the protective sheet 14 on the first laminate 32 is pulled up enough to allow the edge 36 of the second membrane sheet to overlap the exposed edge 38 of the first membrane 32 . The two edges 36 and 38 are then bonded together by heat or adhesive. As shown in FIG. 5 , the edge portion 40 of the protective sheet from the first laminate sheet 32 is then folded back and rests over the overlapped portion 42 of the two membranes 12 , 12 .
As shown in FIG. 1 , the protective sheet 14 covers the entire membrane 12 from side to side. However, as shown in FIG. 8 , the protective sheet 14 may cover the entire membrane except for 4- to 12-inch portions on either edges 26 and 28 of the laminate 10 .
Alternately, as shown in FIG. 9 , the protective sheet 14 can include perforations 50 , 52 along side edges 26 and 28 , which allow strips 54 and 56 to be removed from the sheet leaving the field portion 56 of the protective sheet protecting the membrane. Either of these embodiments allow adjacent sheets of membrane to be bonded together while either the field portion, as in FIG. 9 , or the entire sheet, as in FIG. 8 , remain on the membrane 12 .
Once the roof is fully installed, all of the protective sheets are pulled away from the membrane leaving an exposed white or colored membrane surface free of scratches and dirt. In the event a protective sheet or a portion of a protective sheet is inadvertently left on the roof, sunlight and water will cause it to disintegrate and wash away.
An alternate embodiment of the present invention is shown in FIG. 6 wherein two protective sheets 20 A and 20 B protect the membrane 12 . Sheets 20 A and 20 B overlap in the central portion of the membrane. The overlapped portion 58 lies loose on the membrane 12 . The loose overlapped portions 58 can be easily pulled up, allowing one to remove both protective sheets 20 A and 20 B.
This has been a description of the present invention along with the preferred method of practicing the present invention. However, the invention itself should only be defined by the appended claims, | A roofing laminate includes a roofing membrane, preferably a white roofing membrane, which is covered with a protective sheet. The protective sheet is tinted so that it has a coloration distinguishable from the roofing. The roofing laminate is applied to a roof surface and the release liner protects the outer surface of the membrane from scrapes and dirt during installation. Once the roof is installed the protective sheets are removed from all of the membrane sheets, exposing a clean surface. | 4 |
TECHNICAL FIELD
[0001] This disclosure relates generally to MMICs having capacitors with different capacitances.
BACKGROUND
[0002] As is known in the art, it is sometimes desirable to provide a plurality of different capacitors having different capacitances on a common surface of a substrate providing a Monolithic Microwave Integrated Circuit (MMIC).
SUMMARY
[0003] In accordance with the disclosure, a structure is provided, comprising: a body; a pair of capacitors disposed over different portions of a surface of the body; a first one of the capacitors having an upper conductor and a lower conductor separated by a dielectric layer; and a second one of the pair of capacitors having an upper conductor and a lower conductor separated a dielectric structure, the dielectric structure having a lower dielectric layer, and an upper dielectric layer, wherein the material. of the lower dielectric layer being different from the material of the upper dielectric layer.
[0004] The use of different dielectric materials within the metal-insulator-metal (MIM) capacitor dielectric of a MMIC results in lower MMIC cost, higher reliability and higher performance.
[0005] In one embodiment, a method is provided for forming a plurality of metal-insulator-metal (MIM) capacitors on a surface of a body, the capacitors having different insulator dielectric thicknesses. The method includes: forming a plurality of lower metal conductors over the surface of the body, each one of the conductors providing a lower electrode for a corresponding one of the capacitors; depositing a first dielectric layer over the surface of the body, portions of the first dielectric layer being disposed over the plurality of lower conductors; depositing a second dielectric layer over the first dielectric layer including the portions of the first dielectric disposed over the plurality of lower conductors; forming a mask over the second dielectric layer, such mask having a window therein exposing a first portion of the second dielectric layer disposed over a first one of the lower metal conductors while covering a second portion of the second dielectric layer over a second one of the lower metal conductors; exposing the mask to an etch, the etch having a etch rate in the second dielectric layer being greater than the etch rate in the first dielectric layer, the etch removing the second dielectric layer exposed by the window exposing an underlying portion of the first dielectric layer while leaving the underlying portion of the first dielectric layer over the first one of the lower metal conductors; removing the mask exposing both the second dielectric layer over a second one of the lower metal conductors and the underlying portion of the first dielectric layer over the first one of the lower metal conductors; depositing an upper metal layer over the exposed second portion of the second dielectric layer over a second one of the lower metal conductors and the underlying portion of the first dielectric layer over the first one of the lower metal conductors; and patterning the upper metal layer to form an upper electrode for a first one of the capacitors over the first one of the lower electrodes and an upper electrode for a second one of the capacitors.
[0006] With such an arrangement, a capacitor dielectric stack-up is provided with an etch stop layer (the first dielectric layer) allows design flexibility to remove or not remove the top dielectric layer and change the total thickness.
[0007] The layer thicknesses of the dielectric layers can be Chosen so that a capacitor having both layers can withstand the highest DC plus voltage within the MMIC thereby eliminating the need for multiple capacitors in series. If the upper dielectric layer is etched away to leave only the lower dielectric layer, the lower dielectric layer thickness can be chosen so that it has an adequate breakdown rating for DC bypassing with a smaller area.
[0008] The method can be used to eliminate air bridges: When it is required to have a signal cross another conductor on a without being connected, rather than using an air bridge; the upper metal therein when used with high power may sometimes degrade due to the temperature rise caused by the high RF or DC current levels. By eliminating the air bridge as a cross-over in accordance with the disclosure, a cross-over in accordance with the disclosure has a much better heat path than an air bridge so it will be much less prone to failure while still being able to withstand high RF or DC voltage levels without breakdown.
[0009] In one embodiment, the method includes; forming an additional lower conductor over the surface of the body. Portions of the first dielectric layer are also deposited over the additional lower conductor; portions of the second dielectric layer are deposited over the portions of the first dielectric layer over the additional lower conductor; portions of the mask are deposited over a portion of the second insulating layer over the additional lower metal conductors; portions of the upper metal layer are disposed over the second dielectric layer above the additional lower metal conductor. The patterning of the upper metal layer forms a conductor crossing over the additional lower conductor.
[0010] In one embodiment, the thick top dielectric layer over a Field Effect Transistor (FM) region is etched away to eliminate its additional dielectric loading on the FET performance. Therefore the above benefits for capacitors and air bridge elimination can be achieved with little or no performance impact to the PETs. The added flexibility to choose the thicknesses of the two dielectric layers could also be used to even improve the FET performance.
[0011] The details of one or more embodiments of the disclosure are set forth. in the accompanying drawings and the description below. Other features, objects, and advantages of the disclosure will be apparent from the description and drawings, and from the claims.
DESCRIPTION OF DRAWINGS
[0012] FIG. 1 is a simplified diagraminatical sketch of an Monolithic Microwave Integrated Circuit (MMIC) according to the disclosure; and
[0013] FIGS. 2A-2K are simplified diagrammatical sketch of a process used to form the MMIC at various steps in the manufacture thereof according to the disclosure.
[0014] Like reference symbols in the various drawings indicate like elements.
DETAILED DESCRIPTION
[0015] Referring now to FIG. 1 , a body 10 , here for example a semiconductor body, here, for example, GaN, is formed into a Monolithic Microwave Integrated Circuit (MMIC) 12 . Here, for simplicity, the MMIC circuit 12 will be formed having a FET 14 in a PET region 16 of the body 10 , a high voltage capacitor 18 , in a high voltage capacitor region 20 of the body 10 , slow voltage capacitor 22 formed in a low voltage region 24 of the body 10 , and a conductive cross over 26 formed in a cross over region 28 of the body 10 , as indicated.
[0016] More particularly, referring now to FIGS. 2A-2K , source, and drain electrodes 30 , 32 are formed in ohmic contact with the body 10 , as shown, using any conventional process. A dielectric layer 34 , here for example a 500 Angstrom thick layer of Silicon Nitride (SiN) is deposited over the upper surface of the body 10 and over the source and drain electrodes 30 , 32 . A window 36 ( FIG. 2B ) is formed in the dielectric layer 34 to expose the gate region of the FET. A gate electrode 38 ( FIG. 2C ) is formed in Schottky contact with the exposed portion of the body 10 , as shown.
[0017] Next, lower conductors 40 , 42 and 44 are formed on the first dielectric layer 34 over the high voltage capacitor region 20 , the low voltage capacitor region 24 , and the cross-over region 28 using conventional photolithographic processing, for example. Next, a second. dielectric layer 46 ( FIG. 2D ), here for example a 2000 Angstrom thick layer of Si 3 N 4 is deposited over the surface of the structure; it being noted that the second dielectric layer 46 is deposited on the source electrode 30 , the gate electrode 38 , the drain electrode 32 , and the lower conductors 40 , 42 , 44 with portions second dielectric layer 46 being deposited on portions of the first dielectric layer 34 , as shown.
[0018] Next, a mask 48 is formed on the surface of the MMIC, the mask having windows 50 over the source and drain contacts 30 , 32 , as shown. The portions of the second dielectric layer 46 exposed by the windows 50 are etched away using conventional lithographic etching techniques, for example, to expose the source 30 and drain 32 .
[0019] Next, the mask 48 is removed leaving the structure shown in FIG. 2E .
[0020] Next, a field plate 52 ( FIG. 2F ) is formed, as shown, using any conventional deposition, photolithographic, etching process.
[0021] Next, a dielectric etch stop layer 54 ( FIG. 2G ), here for example Al 2 O 3 having, for example, a thickness of 50 Angstroms, is deposited over the structure. Next, a fourth dielectric layer 56 , here for example, a 6000 Angstroms thick layer of Si 3 N 4 resulting in the structure shown in FIG. 2H .
[0022] Next, a mask. 58 is formed on the surface of the structure, the mask 58 having windows 60 , 62 exposing the FBI region 16 and the low voltage capacitor region 24 but remaining over the high voltage capacitor region 20 and the cross over region 28 , as shown in FIG. 21 . Next, the mask 58 is exposed to an etchant, here for example SF 6 (sulfur hexafluoride) using a Reactive Ion Etcher to remove portions of the fourth dielectric layer 56 exposed by the windows 60 , 62 , thereby exposing underlying portions of the etch stop layer 54 producing the structure shown in FIG. 2J after the mask 58 is removed. It is noted that the SF 6 etches away the exposed portions of the Si 3 N 4 layer at a substantially higher rate (for example at least two orders of magnitude faster) and therefore in essence stops at the underlying portions of the Al 2 O 3 etch stop layer 54 .
[0023] Next, a new mask 64 ( FIG. 2K ) is formed over the structure with windows 66 , 68 in the mask 64 exposing portions of the etch stop layer 54 disposed over the source and drain electrodes 30 , 32 . The exposed portions of the etch stop layer 54 are etched away using a dry etch of Cl 2 and BCl 3
[0024] Next, the mask 64 is removed. A conductor is deposited over the surface of the structure and patterned into the upper conductors 70 a for the source electrode, the drain electrode 70 b, the high voltage capacitor 70 d, the low voltage capacitor 70 c and the cross over conductor 700 using conventional photolithographic-etching techniques, for example, producing the MMIC 12 shown in FIG. 1 .
[0025] A number of embodiments of the disclosure have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the disclosure. For example, a two dielectric structure may be formed, by eliminating etch stop layer 54 and making the lower dielectric layer 46 from the same dielectric material that had been used for the etch stop layer 54 . The thickness of the lower dielectric layer 46 is chosen to meet the capacitance and breakdown voltage requirements for capacitor 22 ( FIG. 1 .), For example, the lower dielectric layer 46 may be, a 2000 Angstrom thick layer of Al 2 O 3 and the upper layer 56 may be a 6000 Angstrom thick layer of Si 3 N 4 ; Where the etch rate to a given etch is substantially faster (for example, at least two orders of magnitude faster) to the Si 3 N 4 that to the Al 2 O 3 Thus, such a two-dielectric structure may be used in place of a three-dielectric structure having a lower 2000 Angstrom thick Si 3 N 4 layer, a 50 Angstrom thick Al 2 O 3 middle, etch stop layer , and a 6000 Angstrom thick Si 3 N 4 upper dielectric layer. Accordingly, other embodiments are within the scope of the following claims. | A structure having; a body; a pair of capacitors disposed over different portions of a surface of the body; a first one of the capacitors having an upper conductor and a lower conductor separated a dielectric layer; and a second one of the pair of capacitors having an upper conductor and a lower conductor separated a dielectric structure, the dielectric structure having a lower dielectric layer, and an upper dielectric layer, wherein the material of the lower dielectric layer is different from the material of the upper dielectric layer. | 7 |
FIELD OF THE INVENTION
This invention relates generally to wireless local loop systems and, in particular, a CDMA-based fixed wireless loop system providing voice and data communications between a radio base unit and a plurality of subscriber stations.
BACKGROUND OF THE INVENTION
Local loop by traditional definition is that portion of a network that connects a subscriber's home to a central office switch. This is, however, an expansive definition that does not hold true as the network extends into the local loop by means of Digital Loop Carrier and Digital Cross Connects. For the purposes of this invention, local loop is considered as the connection from the subscriber's premises to the connecting point in the network, whatever the nature of that connection may be.
Until recently the local loop was mostly based on copper plant supplemented by microwave radio links for remote areas or difficult terrain. Over the last decade fiber optics have made significant inroads into the local loop (also referred to as "access" network) reaching closer to subscriber homes and buildings. Sonet based access networks bring fiber to the curb. These fiber based solutions can provide very high bandwidth services, reliably and cost-effectively, in urban/metropolitan areas with significant number of business customers. In fact, most access providers in the U.S. have used such fiber based plant to provide access services to U.S. business customers.
The copper and fiber based solutions, while economical in many situations, still suffer from a number of drawbacks.
For example, in an area without an existing network infrastructure, it is very time consuming and expensive to build a new network. The expense is primarily in the labor, rights acquisition (for right of way or easement), and in electronics (for fiber based access). Overall the process is very slow due to extensive effort involved in acquiring right of way and in performing the required construction, aerial and/or underground. also, in locations with extensive but congested existing infrastructure, it is often very expensive to add capacity due to already full ducts and cables, and sometimes impossible to add capacity without resorting to upgrading the entire system. In addition, wireline solutions tend to have costs that are distance sensitive, hence they are inherently unsuitable for sparse/scattered demand. Wireline networks are also not amenable to redeployment, which results in stranded assets when demand (consumer) moves. Wireline networks also cannot be rapidly deployed in emergency situations.
The term "fixed wireless loop", or FWL, connotes a fixed wireless based local access. However, it is often mixed with limited mobility solutions under the broader term "Radio Access". Irrespective of the type of radio technology, all fixed wireless or radio access systems use wireless means to provide network access to the subscriber. Broadly speaking, there are three main categories of fixed wireless solutions.
Fixed cellular systems are primarily based on existing analog cellular systems like AMPS (in North America) or NMT (in Nordic countries).
Fixed cordless systems are primarily based on the European DECT standard using digital TDMA Time Division Duplex technology.
Bespoke systems are designed specifically for fixed wireless application. Conventional systems in this category are the analog microwave point to multi-point systems. More recently deployed systems operate at higher frequencies and employ digital technologies. These systems may be derived from similar cellular technologies, but are not based on any existing agreed standards.
Of the three main categories of fixed wireless systems there is no one solution that is clearly superior to others. If the primary need for a system operator is to provide voice oriented service wherein voice quality is not a limiting factor, then often a fixed cellular system is adequate, and even desirable because of its relatively low equipment cost. For very high density url)an situations, a DECT solution may be desirable due to its high load carrying capacity and its pico-cellular architecture. Microwave solutions are best for sparse populations. Bespoke systems function well over a wide range of situations and have the best overall quality and desirable features, however they are likely to be more expensive, at least in the near future.
Most residential consumers in developing economies are mainly interested in adequate voice service. However, most business customers require data and fax service in addition to voice. With the growing popularity of home computers and Internet access, a need is arising to provide residential consumers with high speed data services at home. As such, the general trend is in the direction that all customers, both residential and business, will demand high quality voice and data services.
A problem that arises in a code division multiple access (CDMA) based FWL type system is in the assignment of pseudonoise (PN) spreading codes to different users. Ideally the PN codes form a set of codes that are completely orthogonal and non-interfering. However, in practice complete orthogonality is difficult or impossible to realize. This results in interference between two users transmitting with two non-orthogonal PN codes. Furthermore, the amount of interference between different codes of the set of PN codes can vary depending on which particular codes are assigned at any given time.
OBJECTS AND ADVANTAGES OF THE INVENTION
It is a thus a first object and advantage of this invention to provide an improved fixed wireless loop system that fulfills the foregoing and other needs and requirements.
It is a further object and advantage of this invention to provide an improved fixed wireless loop system that continuously ranks non-assigned PN codes based on interference, and that assigns a new user a PN code that is currently ranked as being a PN code that exhibits a least amount of interference.
SUMMARY OF THE INVENTION
The foregoing and other problems are overcome and the objects and advantages are realized by methods and apparatus in accordance with embodiments of this invention. Disclosed is a method for operating a fixed wireless system having a radio base unit (RBU) that uses a code division multiple access (CDMA) airlink for communicating with a plurality of subscriber units (SUs) within a coverage area of the RBU. The method includes establishing, from a set of pseudonoise (PN) spreading codes, a subset of PN spreading codes that are currently assigned to SUs and a subset of PN spreading codes that are currently not assigned to SUs. The method further ranks the PN spreading codes from the subset of non-assigned PN spreading codes by an amount of interference experienced by the use of eaci non-assigned PN spreading code, and assigns to an SU requiring a PN spreading code a PN spreading code front the set of non-assigned PN spreading codes that is ranked as having a least amount of interference.
The step of ranking the non-assigned PB spreading codes is preferably performed periodically, and includes the steps of assigning, in turn, individual ones of the PN spreading codes from the set of non-assigned PN spreading codes to a correlator of the RBU, and determining an amount of noise output from the correlator resulting from the use of the PN spreading code.
BRIEF DESCRIPTION OF THE DRAWINGS
The above set forth and other features of the invention are made more apparent in the ensuing Detailed Description of the Invention when read in conjunction with the attached Drawings, wherein:
FIG. 1 is a simplified block diagram of a synchronous, DS-CDMA fixed wireless communications system in accordance with this invention, the system having a radio base unit (RBU) and a plurality of transceiver or subscriber units (SUs). The RBU transmits a side channel to the SUs, and also receives an essentially asynchronously transmitted side channel from the SUs.
FIG. 2 is an exemplary frequency allocation diagram of the system of FIG. 1.
FIG. 3 depicts an exemplary arrangement of multiple RBUs each having a coverage area CA.
FIG. 4 illustrates a set of PN codes, the set being divided into currently assigned codes and currently non-assigned codes, with the non-assigned codes being ranked in order of determined interference in accordance with this invention.
FIG. 5 is a graph that illustrates the energy of a matched filter output due to a desired user's signal, due to interfering users, and due to background noise as a function of the timing offset of the matched filter.
FIG. 6 is a block diagram that illustrates the RBU and SU of FIG. 1 in greater detail.
DETAILED DESCRIPTION OF THE INVENTION
By way of introduction, and referring to FIG. 1, a Fixed Wireless System (FWS) 10 in accordance with a preferred embodiment of this invention is a bespoke system based on digital radio technology. Specifically, the FWS 10 employs direct sequence spread spectrum based CDMA techniques over an air link to provide local access to subscribers. It offers very high quality, highly reliable service at costs that are very competitive with wireline solutions. The FWS 10 exhibits high spectral efficiency and thus can provide good wireline quality service with limited available bandwidth. A large dynamic range allows the FWS 10 to be deployable in a pico, micro, or mini cellular architecture meeting specific needs of dense metropolitan, urban, and suburban communities in an economical way.
Some important attributes of the FWS 10 include: wireline voice quality delivered at 32 Kbps; high throughput for data and fax applications with 32/64 Kbps throughput; high service reliability with good tolerance for noise and ingress; secure airlink; and support of enhanced services such as priority/emergency calling, both inbound and outbound.
The FWS 10 has a three to five times capacity advantage over conventional asynchronous CDMA technologies, and a three to seven times capacity advantage over currently available Time Division Multiple Access (TDMA) technology, due to its ability to use a frequency reuse of one.
The FWS 10 is a synchronous CDMA (S-CDMA) communications system wherein forward link (FL) transmissions from a radio base unit (RBU) 12 for a plurality of transceiver units, referred to herein as user or subscriber units (SUs) 14, are symbol and chip aligned in time, and wherein the SUs 14 operate to receive the FL transmissions and to synchronize to one of the transmissions. Each SU 14 also transmits a signal on a reverse link (RL) to RBU 12 in order to synchronize the timing of its transmissions to the RBU 12, and to generally perform bidirectional communications. The FWS 10 is suitable for use in implementing a telecommunications system that conveys voice and/or data between the RBU 12 and the SUs 14.
The SU 14 forms a portion of a Customer Premises Equipment (CPE). The CPE also includes a Network Termination Unit (NTU) and an Uninterruptible Power Supply (UPS), which are not illustrated in FIG. 1.
The RBU 12 includes circuitry for generating a plurality of user signals (USER -- 1 to USER -- n), which are not shown in FIG. 1, and a synchronous side channel (SIDE -- CHAN) signal that is continuously transmitted. Each of these signals is assigned a respective pn spreading code and is modulated therewith before being applied to a transmitter 12a having an antenna 12b. When transmitted on the FL the transmissions are modulated in phase quadrature, and the SUs 14 are assumed to include suitable phase demodulators for deriving in-phase (I) and quadrature (Q) components therefrom. The RBU 12 is capable of transmitting a plurality of frequency channels. By example, each frequency channel includes up to 128 code channels, and has a center frequency in the range of 2 GHz to 3 GHz.
The RBU 12 also includes a receiver 12c having an output coupled to a side channel receiver 12d. The side channel receiver 12d receives as inputs the spread signal from the receiver 12c, a scale factor signal, and a side channel despread pn code. These latter two signals are sourced from a RBU processor or controller 12e. The scale factor signal can be fixed, or can be made adaptive as a function of the number of SUs 14 that are transmitting on the reverse channel. The side channel receiver 12d outputs a detect/not detect signal to the RBU controller 12e for indicating a detection of a transmission from one of the SUs 14, and also outputs a power estimate value χ, as described below. A read/write memory (MEM) 12f is bidirectionally coupled to the RBU controller 12e for storing system parameters and other information, such as SU timing phase information and power estimate values.
A Network Interface Unit (NIU) 13 connects the RBU 12 to the public network, such as the public switched telephone network (PSTN) 13a, through analog or digital trunks that are suitable for use with the local public network. The RBU 12 connects to the NIU 13 using E1 trunks and to its master antenna 12b using a coaxial cable. The SU 14 communicates with the RBU 12 via the radio interface, as described above.
In addition, the FWS 10 has an Element Management System or EMS (not depicted) that provides Operations, Administration, Maintenance, and Provisioning (OAM&P) functions for the NIU 13 and RBU 12. The functioning of the EMS is not germane to an understanding of this invention, and will not be further described in any great detail.
The NIU 13 is the interface to the public network for the system 10. Its primary purpose is to provide the specific protocols and signaling that are required by the public network. These protocols can vary by country as well as by customer, and possibly even by the connecting point in the network.
In a preferred embodiment of this invention the NIU 13 can connect to a maximum of 15 RBUs 12 using one to four E1 connections per RBU 12, with four E1 connections being used for a fully populated RBU 12. In addition, each NIU 13 is sized for up to, by example, 10,000 subscribers. Time Slot 16 on each E1 trunk is used for passing control information between the NIU 13 and the attached RBUs 12, as well as for passing information to and from the controlling EMS. The protocol is based on the HDLC format and optimized to enhance RBU-NIU communication.
Specific functions provided by the NIU 13 include: initialization of the RBU 12; provisioning of dial tone and DTMF to the SUs 14; set up and tear down of voice and data calls; maintenance of Call Detail Record (CDR) data; HDLC Protocol (data link protocol to RBU Link Control Processor); billing system interface; Common Channel Signaling (CCS) for ringing and onhook/offhook detection; glare detection in NIU, RBU, and SU; call priority management; channel reassignment for calls in progress; detection of hook flash to enable plain old telephone service (POTS) and enhanced POTS calling features; 32/64 Kbps rate change initialization; pay phone capability (12/16 KHz tone detection, line reversal); priority and emergency number calling; accommodation of country specific signaling interfaces such as E&M, R1, R2, R2 variants, and C7; and system modularity: analog/digital options for both line side and trunk side.
The normal mode of operation for the SU 14 is a compressed speech mode using ADPCM encoding according to the ITU-T G.721 standard. This toll quality, 32 Kbps service is the default used whenever a non-X.21 channel is established with the RBU 12 (X.21 channels are configured a priori when provisioned by the EMS/NIU). The 32 Kbps channels may be used for voice band data up to 9600 b/s if desired. When the channel rate bumps to 64 Kbps PCM encoded voice/data due to detection of a fax/modem start tone, fax and modem rates of at least 33.6 Kbps are possible.
The SU-RBU air link provides a separate 2.72 MHz (3.5 MHz including guardbands) channel in each direction separated by either 91 MHz or 119 MHz of bandwidth. The nominal spectrum of operation is 2.1-2.3 GHz or 2.5-2.7 GHz. However, the system is designed such that the frequency can be varied from 1.8 to 5 GHz provided the spectral mask and separation between transmit and receive frequencies is maintained as per ITU 283.5 specification. As per the ITU 283.5 specification, there are a total of 96 frequency pairs allowed, as shown in FIG. 2. By example, the RBU 12 may transmit in the 3' frequency band and receive in the 3 frequency band, and the SU 14 transmits in the 3 frequency band and receives in the 3' frequency band. The RBU 12 can support 128 simultaneous 34 Kbps channels using the 2.72 MHz bandwidth giving it a spectral efficiency of 1.6 bits/Hz. Of this total capacity, 8 channels are used by the FWS 10 and an additional 2 Kbps per channel is system overhead. Thus the effective traffic carrying capacity is 120 channels at 32 Kbps.
The spectral efficiency of the FWS 10 is three to five times that of conventional CDMA systems primarily because the FWS 10 employs bi-directional Synchronous CDMA. Competing systems, including those based on IS-95, are asynchronous or synchronous only in one direction. The bi-directional synchronicity permits the FWS 10 to use near orthogonal spreading codes and gain maximum possible data carrying capacity.
Radio emissions lose energy as they travel in air over long distances. In order to ensure that the received signal energy from a distant subscriber is not completely overwhelmed by that of a near subscriber, the RBU 12 controls the power level of the SUs 14. In the preferred embodiment only the reverse channel power (from SU 14 to the RBU 12) is controlled by the RBU 12. The power control is primarily established at SU 14 initialization.
Subsequent power adjustments are infrequent and are made in response to transient environmental conditions. The closed loop power control is implemented by comparing against a desired power level and making incremental adjustments until the desired level is achieved.
The forward channel power control is not needed since each SU 14 receives its entire signal at only one level. The RBU 12 merely needs to ensure that the received signal strength by the farthest SU 14 is sufficient for its application.
It is not always desirable to have an extended range. In a dense urban or even a suburban setting, one needs to deploy the system in a cellular architecture as depicted below. To reduce interference between sectors and between cells in such a deployment, the range of the RBU is limited overall as well as selectively in specific directions. Such range control may be accomplished using a directional master antenna 12b at the RBU 12, as well by controlling overall RBU power.
When one of the SUs 14 detects an off-hook (the user has picked up the phone), it transmits an outgoing call request on one of six reverse synchronous side channels in a Slotted ALOHA fashion. The side channel is chosen at random. The RBU 12 processes the request and, providing an active channel is available, sends an outgoing call reply to the SU 14 which contains the active channel codes (both forward and reverse). In the meantime, the RBU 12 begins to transmit forward side channel data on the newly activated channel and at a given time, begin to transmit the active call data. The SU 14, which is listening to the forward side channel, receives the active channel assignment and switches at a superframe boundary to the active codes. The SU 14 then begins to receive the side channel data and then the active call data.
When an incoming call is received by the NIU 13 for one of the SUs 14 in the local loop, the RBU 14 is notified over the E1 link. The RBU 12 first checks to determine if the intended SU 14 is busy. If not, the RBU 14 sends a message to the SU 14 on the forward side channel, the message containing the active channel codes. The call processing then continues in the same manner as the outgoing call processing discussed above.
If all channels are busy and the NIU 13 receives an incoming call for a non-busy SU 14, it provides a subscriber busy tone to the caller unless the called SU has priority inbound access (such as a hospital, fire station, or police), in which case the NIU 13 instructs the RBU 12 to drop the least priority call to free up a channel for the called SU 14. Similarly, if an SU 14 initiates a request for service and no traffic channels are open, then the RBU 12 provides the dial tone on a temporary traffic channel and receives the dialed number. If the dialed number is an emergency number the RBU 12 drops a least priority call to free up a traffic channel and connects the free channel to the SU 14. If the called number is not an emergency number then the SU 14 is provided a special busy tone indicating a "wait for service" condition.
Reference is now made to FIG. 6 for illustrating the RBU 12 and SU 14 in greater detail.
An incoming call from the PSTN 13a passes through the NIU 13 to 64 Kbps per channel E1 trunks 13b and then to a RBU-resident E1 interface 2U. The E1 interface 20 optionally performs an A-Law ADPCM algorithm for the compression of the 64 Kbps channel to a 32 Kbps channel that is placed on a PCM highway 21 time slot. If the A-Law ADPCM compression is bypassed, the 64 Kbps channel is split into two 32 Kbps channels and placed onto the PPCM Highway 21. In the preferred embodiment the RBU 12 can accommodate up to 128 32 Kbps channels, and each SU 14 can accommodate up to four 32 Kbps channels. The PPCM Highway 21 operates in conjunction with a frame synchronization (FrameSync) signal 20a, which represents a master timing pulse that is generated every 16 ms. All calls to and from the RBU 12 pass through the PPCM Highway 21 and the E1 interface 20. For the case of an incoming call the signal is applied to a baseband combiner (BBC) 22 and thence to a D/A converter 24 and a transmit radio frequency front-end (RFFE) 26 before being applied to the antenna 12b for transmission to the SU 14. At the SU 14 the incoming call signal is received by the antenna 14a and is applied to a receive RFFE 34, an A/D 36, demodulator 38 and a receiver 40. The SU 14 includes a subscriber line interface circuit (SLIC) 42 that couples a pulse code modulation (PCM) Highway 41 to a network termination unit (NTU) 52. In the reverse direction a call originates at the NTU 52 and passes through the SLIC 42 and PCM Highway 41 to a transmitter 44, modulator 46, D/A converter 48 and a transmit RFFE 50. The signal is applied to the SU antenna 14a and is received by the RBU antenna 12b. The received signal is applied to a receive RFFE 28, A/D converter 30, a demodulator and synchronization unit 32, and then to the PPCM Highway 21 and E1 interface 20 for connection to the PSTN 13a via one of the E1 trunks 13b and the NIU 13.
The RBU 12 controls the master timing for the entire FWS 10. Timing throughout the FWS 10 is referenced to the periodic timing pulse generated at the PPCM Highway 21, i.e., to the FrameSync signal 20a. In the FWS 10 all data is grouped into equal-sized packets referred to as frames, which in turn are grouped into super-frames with, for example, three frames making up one super-frame.
Having described the overall architecture and capabilities of the FWS 10, a detailed description of this invention will now be made.
Reference is first made to commonly assigned and allowed U.S. patent application Ser. No. 08/606,378, filed Feb. 23, 1996, now U.S. Pat. No. 5,805,584 entitled "A Multi-User Acquisition Procedure for Point-To-Multipoint Synchronous CDMA Systems", by S. C. Kingston, T. R. Giallorenzi, R. R. Sylvester, D. Matolak, and P. Smith, the disclosure of which is incorporated by reference herein in its entirety. In this commonly assigned patent application a technique is disclosed for the SU 14 to acquire the correct code timing for a synchronous CDMA forward channel link in the presence of multi-user interference (MUI). This technique exploits the orthogonality of the PN codes used to determine the proper code phase by purposely despreading a PN code (i.e., a null code) which is known to not be present (i.e., not transmitted by the RBU 12). This is done to overcome the problem that arises when using a conventional acquisition procedure when many users are active. In this case the interference energy of P-1 interfering users, with processing gain P, can be nearly as strong as the energy of the desired user's signal. As a result, the standard acquisition approach, wherein a detection is declared when the energy of a matched filter output (or sliding correlator output) is larger than a threshold, is not viable in a heavily loaded system. A simplifying assumption made herein is that the frequency offset between the carrier of the incoming signal and the receiver's local oscillator is zero.
FIG. 5 illustrates the energy of the matched filter output due to the desired user's signal, due to the interfering users, and due to the background noise as a function of the timing offset of the matched filter. It should be noted that on the forward channel, the user signals are all assumed to perfectly synchronized with each other. The different curves shown in FIG. 5 represent the various components of the received signal, and the sum of these components make up the received strength. It is important to note that the MUI energy due to a receiver chip timing offset is comparable to the energy of the desired user's signal when the receiver is not offset. The implication of this is that a standard acquisition algorithm would not be able to easily distinguish the difference between the offset and synchronized phases. In fact, unless additional averaging takes place, the signal energy is essentially equal to the noise variance, which implies a detection signal-to-noise ratio (SNR) of approximately 0 dB.
It should also be noted that the noise due to MUI and the noise due to background noise are both zero mean noise processes. In the conventional detection procedure, the absolute value of the larger of I and Q despreader outputs are taken and the results are averaged over some dwell time. The fact that the noise has a zero mean implies that it is possible to increase the decision SNR by averaging the detection statistics. However, in the case of a heavily loaded system, the averaging time would be required to be long in order to create a large enough SNR to determine reliably whether the receiver is correctly synchronized to a signal.
In contrast with the standard acquisition approach, and in accordance with the invention disclosed in the commonly assigned patent application referred to above, if the receiver 14b of the SU 14 instead despreads a PN code which is not transmitted, then the noise will be "tuned out" when the receiver comes into alignment with the interfering signals. This implies that the SU receiver 14b can look for the "hole in the noise" which occurs at the zero offset phase, and thus determine when the noise energy at a sliding correlator output drops below a threshold. At this time the acquisition circuit can declare that a lock has occurred. This technique can be referred to as a multi-user test (MUT).
FIG. 3 depicts an exemplary arrangement of multiple RBUs 12 each having an associated coverage area (CA). In the preferred embodiment of this invention there are up to 19 sets of scrambled Walsh-Hadamard pseudonoise (PN) spreading codes defined, with each set containing 128 PN codes of length 128. Each RBU 12 operates with a different set of 128 PN codes (one PN code in each set is the above-described null code). The PN spreading codes used by a particular RBU 12 are not guaranteed to be orthogonal to the set of PN spreading codes used by an adjacent RBU 12, and furthermore the timing of adjacent RBUs is not aligned. These factors result in interference between RBU CAs. Also, the filtering performed by the RBU and SU receivers causes some distortion, thereby destroying any possibility of achieving complete orthogonality within a given PN code set. The end result is a variable amount of interference that can be experienced using a given PN code, wherein the interference varies as function of at least the identities of the PN codes that are currently assigned within a given RBU CA, as well as those codes that are currently assigned within neighboring RBU CAs. By example, during a certain period of time PN codes 1 and 17 may exhibit a minimal amount of mutual interference within a given one of the RBU CAs, while at the same time PN codes 5 and 17 may exhibit a significant amount of mutual interference. At some later time the situation may be reversed.
The inventors have realized that if the RBU 12 were to assign PN codes to new users without regard for these factors then some users could be assigned PN codes that are not optimum, at that particular time, for achieving the low symbol error rates that are an important feature of the FWS 10.
FIG. 4 illustrates an illustrative set 19 of PN spreading codes that are assigned to one of the RBUs 12 of FIG. 3, the set 19 being divided into a subset of currently assigned codes 19A and a subset of currently non-assigned codes 19B. In accordance with this invention each RBU 12 operates to rank the subset of non-assigned codes 19B in order of interference. This is preferably achieved in a manner similar to that described above for the SU-executed null code MUT determination.
In accordance with this invention the RBU 12 periodically (e.g., once per second) sets one of its correlators to despread the received signal energy using one of the non-assigned PN codes 19B. The output of the correlator (despreader) is then detected to determine the amount of received energy (noise) that results from the use of the non-assigned PN code. Each PN code from the set of non-assigned PN codes 19B is similarly tested in succession, and the non-assigned PN codes of the set 19B are then ranked in order of quality (e.g., 1-n, with the PN code ranked as 1 being the non-assigned PN code that currently exhibits the least interference and the PN code ranked as `n` being the non-assigned PN code that currently exhibits the most interference.) The ranking of the non-assigned PN codes from the set 19B can be performed as a background task by the RBU controller 12e during spare CPU time.
When the RBU 12 receives a request by one of the SUs 14 to be assigned a PN code, the RBU 12 selects as a next to be assigned PN code that PN code ranked as the least interfering within the subset of non-assigned PN codes 19B.
By so ranking the non-assigned PN codes by interference level the RBU 12 is enabled to accommodate the variabilities in PN code performance induced by the changing combinations of currently assigned PN codes in the RBU's CA, as well as the variabilities induced by the PN codes that are currently assigned by neighboring (if any) RBUs 12.
While described in the context of specific types of PN codes having a particular length, numbers of PN codes per RBU PN code set, and so forth, it should be realized that these specific embodiments are not intended to be read in a limiting sense upon the teachings of this invention.
Thus, while the invention has been particularly shown and described with respect to preferred embodiments thereof, it will be understood by those skilled in the art that changes in form and details may be made therein without departing from the scope and spirit of the invention. | Disclosed is a method for operating a fixed wireless system (FWS) having a radio base unit (RBU) that uses a code division multiple access (CDMA) airlink for communicating with a plurality of subscriber units (SUs) within a coverage area of the RBU. The method includes establishing, from a set of pseudonoise (PN) spreading codes, a subset of PN spreading codes that are currently assigned to SUs and a subset of PN spreading codes that are currently not assigned to SUs. The method further ranks the PN spreading codes from the subset of non-assigned PN spreading codes by an amount of interference experienced by the use of each non-assigned PN spreading code, and assigns to an SU requiring a PN spreading code a PN spreading code from the set of non-assigned PN spreading codes that is ranked as having a least amount of interference. The step of ranking the non-assigned PN spreading codes is preferably performed periodically, and includes the steps of assigning, in turn, individual ones of the PN spreading codes from the set of non-assigned PN spreading codes to a correlator of the RBU, and determining an amount of noise output from the correlator resulting from the use of the PN spreading code. | 7 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of U.S. patent application Ser. No. 10/496,195, filed Dec. 21, 2004, which is a 35 U.S.C. §371 application of PCT/CA02/01765, filed Nov. 21, 2002, the contents of which are incorporated by reference as if fully set forth.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to improvements in devices for use as grinding cups for grinding the hard metal inserts or working tips of drill bits (percussive or rotary), tunnel boring machine cutters (TBM) and raised bore machine cutters (RBM) and more specifically, but not exclusively, for grinding the tungsten carbide cutting teeth or buttons of a drill bit or cutter.
[0003] In drilling operations the cutting teeth (buttons) on the drill bits or cutters become flattened (worn) after continued use. Regular maintenance of the drill bit or cutter by regrinding (sharpening) the buttons to restore them to substantially their original profile enhances the bit/cutter life, speeds up drilling and reduces drilling costs. Regrinding should be undertaken when the wear of the buttons is optimally one third to a maximum of one-half the button diameter.
[0004] Different manual and semi-automatic grinding machines are known for grinding button bits/cutters (see for example U.S. Pat. Nos. 5,193,312; 5,070,654). In a conventional type of machine a grinding cup having the desired profile is rotated at high speed, typically from about 15,000 to 25,000 RPM, to grind the carbide button and the face of the bit/cutter surrounding the base of the button to restore the button to substantially its original profile for effective drilling.
[0005] The grinding cups conventionally consist of a cylindrical body having top and bottom surfaces. The bottom or working surface consists of a diamond/metal matrix having a centrally disposed convex recess having the desired profile for the button to be ground. The rim around the recess may be adapted, for example by bevelling, to remove steel from the face of the bit around the base of the button.
[0006] Water and/or air, optionally with some form of cutting oil, is provided to the grinding surface to flush and cool the surface of the button during grinding.
[0007] The grinding cups are provided in different sizes and profiles to match the standard sizes and profiles of the buttons on the drill bits or cutters. Typically the button diameter varies from 6 mm up to 26 mm.
[0008] Several different methods are used to connect and retain the grinding cups on to the grinding machine. The grinding cups were conventionally held in the grinding machine by inserting an upright hollow stem projecting from the top surface of the grinding cup into a chuck for detachable mounting of tools. Special tools such as chuck wrenches, nuts and collets are necessary to insert, hold and to remove the grinding cup into and out of the chuck.
[0009] To eliminate the need for chuck wrenches etc. the use of a shoulder drive on the grinding cups was developed. A diametrically extending recess at the free end of a hollow drive shaft of the grinding machine co-operates with a shoulder or cam means on the adjacent top surface of the grinding cup. The stem of the grinding cup is inserted into the hollow drive shaft and maybe held in place by one or more O-rings either located in a groove in the interior wall of the drive shaft or on the stem of the grinding cup. See for example Swedish Patent No. B 460,584 and U.S. Pat. No. 5,527,206.
[0010] An alternative to the shoulder drive is that shown, for example, in Canadian Patent 2,136,998. The free end of the stem of the grinding cup is machined to provide flat drive surfaces on the stem that are inserted into a corresponding drive part in the channel of the output drive shaft into which the stem is inserted. The grinding cup is retained in place by a spring biased sleeve which forces balls mounted in the wall of the output drive shaft into an annular groove on the stem of the grinding cup.
[0011] Other innovations are illustrated in U.S. Pat. Nos. 5,639,273 and 5,727,994. In these patents, the upright stem has been replaced with a centrally disposed cavity provided in the top surface of the grinding cup. The cavity is shaped and sized to permit the output drive shaft of a grinding machine to be inserted into the cavity.
[0012] Some manufacturers, in order to provide grinding cups that are compatible for use with other manufacturers' grinding machines provide adapters that connect their grinding cup to the output drive shaft of competitors' grinding machines.
[0013] Regardless of the method of connecting the grinding cup to the output drive shaft of the grinding machine, it is important to optimize the operational stability of the grinding cup. Lack of operational stability often results in vibration and resonance during grinding. Vibration and/or resonance also directly results in increased rates of wear to all moving parts such as bearings, joints, etc. of the grinding apparatus and can potentially interfere with settings within the operating control circuits of the grinding apparatus. In addition, lack of operational stability results in increased wear to all key drive/contact surfaces of the output drive shaft (rotor) and grinding cup which provide consistent, proper alignment between grinding cup and or adapter and the rotor during operation. Operational instability and associated vibration and/or resonance is a major contributor to the deterioration of the preferred built-in profile of the cavity in the grinding section of the grinding cup. This directly results in deterioration in the profile of the restored button. The net effect being a substantial loss in the intended overall drilling performance of the drill bit or cutter used.
[0014] The grinding cups are conventionally manufactured by first forming a blank for the body section by machining, casting, forging etc. It is necessary to machine different blanks for each size of button to be ground and for the different methods of attaching the grinding cup to the grinding machine. This results in higher costs of manufacture and a large inventory of parts for manufacture of the grinding cups over the full range of sizes, shapes and methods of connection. The blank is then pressed into a mould containing a hot diamond/metal mixture. The bottom surface of the blank is heated and bonds to the diamond/metal matrix. Several means of heating and bonding the diamond/metal matrix to the blank are known. Alternatively the diamond/metal matrix can be formed into the grinding section and then bonded either by a shrink fit and/or with adhesives or solder to a blank.
SUMMARY OF THE INVENTION
[0015] It is an object of the present invention to standardize components regardless of the size of the button to be ground or method of connection to reduce manufacturing costs. Standardized components can be manufactured in relatively large quantities and then used to assemble grinding cups according to the present invention.
[0016] It is a further object of the present invention to provide a standardized grinding member for each size and shape of button to be ground that can be custom connected to different or re-useable drive means.
[0017] It is an object of the present invention to reduce negative impact on operational stability, drive/contact surface wear/damage, wear/damage and/or deformation of materials in the drive and/or contact areas, as well as other potential associated wear/damage to the grinding apparatus caused by vibration and/or resonance.
[0018] It is a further object of the present invention to improve operational stability by optimizing/harmonizing the forces transferred between the rotor and grinding cup or grinding cup and adapter or adapter and rotor during operation including torsion (rotational) forces, axial (feed) forces and radial (varying side load) forces.
[0019] It is a further object of the present invention to optimize the alignment between the grinding member and drive connection member.
[0020] Accordingly the present invention provides a grinding member for connection to a drive connection member for grinding the hard metal inserts or working tips of drill bits (percussive or rotary), tunnel boring machine cutters (TBM) and raised bore machine cutters (RBM) to restore them to substantially their original profile. The grinding member has:
[0021] (a) a grinding section having top and bottom surfaces, a centrally disposed convex recess formed in the bottom surface of said grinding section having the desired profile to be ground;
[0022] (b) a support section adjacent the top surface of said grinding section; and
[0023] (c) means to connect the grinding member to the drive connection member wherein the grinding member can be disconnected from the drive connection member when it becomes worn.
[0024] In a preferred embodiment the means to connect the grinding member to the drive connection member drive consists of a longitudinally extending stub adapted to fit in a corresponding recess on said drive connection member.
[0025] In another aspect the present invention provides a drive connection member having a first section adapted for connection to the grinding member and a second section adapted to detachably connect to the output drive shaft of a grinding machine. The second section consists of a drive section and a support section and preferably has engagement surfaces sized and shaped to substantially match contact areas on the output drive shaft of the grinding machine or any adapter connecting said drive connection member to the output drive shaft of a grinding machine.
[0026] Further features of the invention will be described or will become apparent in the course of the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] In order that the invention may be more clearly understood, the preferred embodiment thereof will now be described in detail by way of example, with reference to the accompanying drawings, in which:
[0028] FIG. 1 is a side elevation, partly in section, of an embodiment of a grinding member and a drive connection member utilizing a shoulder drive according to the present invention;
[0029] FIG. 2 is a side elevation, partly in section, of an embodiment of a grinding member and another drive connection member utilizing a hex drive according to the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0030] The present invention is illustrated in FIG. 1 in conjunction with grinding cups utilizing a shoulder drive but is also applicable to other types of drive means on grinding cups.
[0031] Referring to FIG. 1 , one embodiment of a grinding cup according to the present invention is generally indicated at 1 . The grinding cup 1 is for use with a grinding machine of the type which incorporates a diametrically extending slot at the free end of the output drive shaft of the grinding machine that co-operates with a shoulder or cam means on the adjacent top surface of the grinding cup such as described in U.S. Pat. No. 5,527,206.
[0032] The grinding cup 1 is formed of two distinct components: a grinding member 2 and drive connection member 3 . The grinding member 2 has a grinding section 4 formed from a material capable of grinding the tungsten carbide inserts of button bits. In the preferred embodiment, the grinding section 4 is formed from a metal and diamond matrix. The peripheral edge 5 in the bottom surface 6 of the grinding section 4 is preferably beveled to facilitate the removal of steel from the face of the bit around the base of the button during grinding. Other means for removal of steel from the face of the bit around the base of the button either during or before or after grinding are known including the use a separate tool for this purpose, use of wear splines or broach marks around the periphery or varying the angle of the peripheral edge. A centrally disposed convex recess 7 is formed in the bottom surface 6 having the desired size and profile for the button to be ground.
[0033] Preferably integral with and adjacent the top surface 8 of the grinding section 4 is a support section 9 whose bottom surface 10 is bound to the top surface 8 of the grinding section 4 . Several means of heating and bonding the diamond/metal matrix of the grinding section 4 to support section 9 are known. The support section 9 consists of a metal portion 11 , machined, forged or cast. The metal portion 11 for the support section 9 can be machined either before or after it is attached to diamond/metal grinding section 4 . while the portion 11 is referred to as being made of metal in the preferred embodiment, the present invention can include the use of non-metallic materials or a combination of non-metallic and metallic materials to form support section 9 and portion 11 . The preferred procedure would be to the extent possible pre-machine the support section 9 before attaching the grinding section 4 . Alternatively the grinding section 4 and support section 9 can be formed at the same time. In any event some form of post-furnace machining may be required for clean up purposes. Clean up of the exterior surfaces post-furnace is carried out by holding the grinding section 4 in the chuck of a lathe and then skimming the relevant surfaces wherever needed. At this time it is also possible to remove additional material wherever suitable. Post-furnace machining is used to remove “flash” and other matrix material which may have seeped out of the mold during furnacing/pressing. The thickness T of the metal portion 11 of the support section 9 should be sufficient to provide structural support for the grinding section 4 .
[0034] Means 13 to connect the grinding member 2 to the drive connection member 3 are provided on the top edge 14 of the support section 9 . The means 13 to connect the grinding member 2 to the drive connection member 3 can be formed integrally with the support section 9 and machined to the desired configuration or cast separately and attached to the support section 9 . In the embodiment illustrated in FIG. 1 , the diameter of the support section 9 relative to the size of the grinding section 4 is optimized to reduce the mass of the grinding member 2 by machining the peripheral surface 15 to its top edge 14 in a profile generally corresponding to the profile of the top surface 8 of the grinding section 4 .
[0035] In the embodiment illustrated in FIG. 1 , the means 13 to connect the grinding member 2 to the drive connection member 3 , consists of a generally cylindrical section 16 whose bottom edge 17 is attached and/or with the top edge 14 of support section 9 . A cylindrical stub 18 is centrally located on the top edge 19 of the cylindrical section 16 . The stub 18 is intended to be inserted into a corresponding cavity on the drive connection member 3 in a manner ( 1 ) that will prevent the grinding member 2 from rotating or spinning free relative to the drive connection member 3 ; ( 2 ) that will support axial, radial, torsion and feed forces associated with the use of the grinding cup and (3) optionally permit removal of a grinding member 2 with worn grinding section 2 and replacement with a new grinding member to permit re-use of the drive connection member. In the preferred embodiment illustrated the stub 18 is press fit into the drive connection member. Alternatively a stub on the drive connection member could fit into a corresponding cavity on the grinding member. Some examples of other possible connection methods are taper fits, threaded connections, adhesives, solder, friction welding and pins. Preferably the connection method permits the grinding member 2 to be disconnected from the drive connection member 3 only by the factory and not the end user. Accordingly connection methods would be preferably be selected from press fit, shrink fit, some adhesives, solder, or possibly friction welding as these methods are not likely to permit disconnection by the end user which would be the case for threaded connections or the use of pins.
[0036] A passageway 20 through the grinding member 2 connects to one or more outlets 21 in the grinding section 4 to permit a coolant, preferably water, optionally mixed with cutting oil or a water/air mist, to be provided to the surface of the button during grinding. The coolant prevents excessive heat generation during grinding and flushes the surface of the button of material removed during grinding. In addition, the diameter of the passageway 20 through the support section 9 and means 13 may be expanded to reduce the mass of the grinding section.
[0037] In the present invention the grinding member 2 for any particular size and shape of convex recess 7 is the same regardless of the method of connecting the grinding cup to the output drive shaft of a grinding machine. Standardizing the components will reduce manufacturing costs and the amount of inventory required.
[0038] The drive connection member 3 in the embodiment illustrated in FIG. 1 is illustrated as a separate component to be connected to the output drive shaft of a grinding machine utilizing one of the known drive methods identified previously. The drive connection member in FIG. 1 has a first section 22 adapted for connection to the grinding member 2 and a second section 23 adapted to detachably connect to the output drive shaft of a grinding machine. The first section 22 , in the embodiment illustrated the outer wall 24 of first section 22 , generally cylindrical in the embodiment shown although other shapes are possible, defines a recess 25 adapted to receive the stub 18 of the grinding member 2 . The stub 18 is adapted to fit within recess 25 so that the grinding member 2 cannot rotate or spin relative to the drive connection member 3 . The bottom 26 of the outer wall 24 is sized and shaped to fit against the top edge 19 of the cylindrical section 16 of means 13 on the grinding member 2 . While the stub 18 and recess 25 are illustrated as circular in cross section other shapes are possible such as elliptical, oval, square, rectangular, hexagonal etc. As noted previously it is within the scope of the present invention to have a stub on the drive connection member fit within a recess on the grinding member.
[0039] The second section 23 of the drive connection member is integral with the top 27 of the outer wall 24 of the first section. The configuration of the second section 23 will vary depending on the drive system on the grinding machine to which the grinding cup is intended to be attached. Regardless of the drive system being utilized, in general the second section 23 will have a drive section and a support section. In FIG. 1 the drive system to which the drive connection member 3 is intended to co-operate is a shoulder drive system. In the illustrated embodiment the drive section, generally indicated at 28 , cam means or shoulder 29 provided at the top 27 of the outer wall 24 of the first section 22 . The cam or shoulder 29 is sized to engage with a diametrically extending slot at the free end of the output drive shaft of a grinding machine. The cam 29 has an upper surface 30 , parallel side walls 31 and end walls 32 . The support section, generally indicated at 33 , consists of a hollow vertical upright stem 34 centrally located on the upper surface 30 of the cam 29 . The hollow stem 34 is intended to be inserted into a corresponding axial recess in the output shaft of the grinding machine. Retaining means 35 are provided in conjunction with the upright stem 34 to releasably secure the grinding cup to the output shaft of the grinding machine during use. In the preferred embodiment illustrated in FIG. 1 , the retaining means 35 are one or more O-rings 36 located in one or more grooves 37 on the stem 34 . Optionally the retaining means could also be located on the output drive shaft or a combination on both the grinding cup and the drive shaft working independently or cooperatively.
[0040] In the embodiment shown, the drive section 27 is adapted to optimize contact between the engagement surfaces (upper surface 30 and side walls 31 of cam 29 ) on the drive connection member 3 and the corresponding engagement surfaces on the output drive shaft of the grinding machine to reduce vibration to reduce rotor wear, as well as other potential associated wear to the grinding apparatus caused by vibration and/or resonance and to improve operational stability by optimizing and harmonizing the forces transferred between the rotor and grinding cup during operation including torsion (rotational) forces, axial (feed) forces and radial (varying side load) forces and to reduce negative impact on operational stability, drive/contact surface wear/damage, wear/damage and/or deformation of materials in the drive and/or contact areas.
[0041] In the embodiment shown, cam means or shoulder 29 is sized and shaped so that the engagement surfaces on said cam or shoulder are optimized to and match with the corresponding engagement surfaces of slot on the output shaft of the grinding machine. In addition the cam or shoulder 29 is preferably substantially the same length, width and depth as the diametrically extending slot at the free end of the output drive shaft of the grinding machine. This optimizes the contact area between the walls of slot on the drive shaft and the upper surface 30 and side walls 32 of the cam 29 resulting in reduced vibration and rotor wear, as well as other potential associated wear to the grinding apparatus caused by vibration and/or resonance. Reduced vibration also improves operational stability, drive/contact surface wear/damage, wear/damage and/or deformation of materials in the drive and/or contact areas by optimizing and harmonizing the forces transferred between the rotor and grinding cup during operation including torsion (rotational) forces, axial (feed) forces and radial (varying side load) forces. In addition, substantially reducing vibration and/or resonance, minimizes the deterioration of the preferred built-in profile of the cavity in the grinding section.
[0042] To optimize and harmonize the various loads such as torsion loads and resulting operational loads such as radial and axial loads over a range of various sizes and profiles of grinding cups, the cam or shoulder may be sized differently in relation to the diametrically extending slot at the free end of the output drive shaft or adaptor if one is being used.
[0043] The above noted methods to optimize the contact area between the drive shaft and the grinding cup and standardize components, wherever practical, regardless of the size of the button to be ground will reduce manufacturing costs. In addition, this results in less vibration to reduce rotor wear, as well as other potential associated wear to the grinding apparatus caused by vibration and/or resonance and reduces negative impact on operational stability, drive/contact surface wear/damage, wear/damage and/or deformation of materials in the drive and/or contact areas by optimizing and harmonizing the forces transferred between the rotor and grinding cup during operation including torsion (rotational) forces, axial (feed) forces and radial (varying side load) forces. In addition, deterioration of the preferred built-in profile of the cavity in the grinding section is minimized. Consideration is given to the size of the grinding cup, the drive means selected, manufacturing costs, materials of construction, areas required for product identification and necessary structural strength and/or support in implementation of the present invention.
[0044] Alternative manufacturing methods in order to achieve further standardization, simplify manufacturing, reduce costs and minimize inventory are within the scope of the present invention. Alternative materials (both metallic and non-metallic or a combination thereof) and processes can be used that are currently incompatible with any one or more parts or the manufacturing process. For example, brass is not normally compatible with many forms of sintering, etc., due to the fact that it cannot take the heat necessary to produce a good bond within the diamond matrix of the grinding section. Making a separate drive connection member out of brass and attaching the grinding member, post furnace, would make this possible. Heat treating the drive connection member may not feasible when done on a finished grinding cup, but on a re-useable one, it may be both operationally beneficial and cost efficient for the user. Non-metallic materials, such as plastics, polymers or elastomeric material and the like, can be used in mating surfaces between the grinding member and the drive connection member and or drive connection member and the output drive shaft or adapter. Non-metallic materials can be selected to provide anti-wear characteristics, provide anti-vibration characteristics or allow mating surfaces to be more forgiving when dirt is present, potentially reducing problems within the mating sections. Similarly the components of the grinding member and drive connection member can be made from metallic or non-metallic materials or a combination of both in order to facilitate use of alternative manufacturing methods such as injection molding, casting, powder metallurgy etc to make some of the components at a lower cost.
[0045] Since a standardized drive connection member according to the present invention, can be mass produced, the advantage of higher precision, reduced cost, etc. are possible by the category of machining equipment available to make this component. Further by making a standardized drive connection member with greater precision could result in better dynamic balance, etc. due to factors such as less runout, etc. Any other components that can be standardized can be manufactured in relatively large scale and then used to assemble grinding cups according to the present invention.
[0046] FIG. 2 illustrates a grinding cup formed from two components a grinding member and drive connection member for connection to grinding machine utilizing a hex drive system as illustrated in U.S. Pat. No. 5,727,994. The grinding member 2 is the same as described above in connection with FIG. 1 . The drive connection member generally indicated at 303 in the embodiment illustrated in FIG. 2 has a first section 322 adapted for connection to the grinding member 2 and a second section 323 adapted to detachably connect to the output drive shaft of a grinding machine. The first section 322 , in the embodiment illustrated the outer wall 324 of first section 322 defines a recess 325 adapted to receive the stub 18 of the grinding member 2 . The stub 18 is adapted to fit within recess 325 so that the grinding member 2 cannot rotate or spin relative to the drive connection member 303 . The bottom 326 of the outer wall 324 is sized and shaped to fit against the top edge 19 of the cylindrical section 16 of means 13 on the grinding member 2 . Alternatively a stub on the drive connection member could fit into a corresponding cavity on the grinding member. Other possible connection methods are taper fits, threaded connections, adhesives, solder, friction welding and pins.
[0047] The second section 323 of the drive connection member 303 is integral with the top 327 of the outer wall 324 of the first section. The configuration of the second section 323 will vary depending on the drive system on the grinding machine to which the grinding cup is intended to be attached. Regardless of the drive system being utilized, in general the second section 323 will have a drive section and a support section. In FIG. 2 as previously indicated the drive system to which the drive connection member 303 is intended to co-operate is a hex drive system. In the illustrated embodiment the drive section, generally indicated at 328 , is intended to cooperate with the output shaft of the grinding machine. In the embodiment illustrated in FIG. 2 , the second section 323 has a outer wall 304 defining a centrally disposed cavity 315 open at the top 305 of the outer wall 304 . This cavity 315 is shaped and sized to permit the drive connection member 303 to be detachably connected to the output drive shaft of the grinding machine and rotated during the grinding operation. The end portion of the output drive shaft is adapted to fit within the corresponding sized centrally disposed cavity 315 . The output drive shaft is adapted to driveably engage within cavity 315 . In the preferred embodiment shown the top portion 316 of cavity 315 in second section 323 is adapted to define drive section 328 . In the embodiment shown, drive section 328 is machined with a hexagonal cross section corresponding to the shape of the corresponding drive section on the output shaft of the grinding machine. The drive section 328 can be formed other than by machining. To provide support for the grinding cup and minimize vibration generated axial side load on the grinding cup, the free end of the output drive shaft is adapted to fit snugly within the bottom portion 317 of cavity 315 in the second section 323 of the drive connection member 303 . In the embodiment illustrated, both the free end of the output drive shaft and the bottom portion 317 of cavity 315 would have a circular cross section slightly smaller in diameter than the hexagonal drive section 328 . Other arrangements are possible, for example the support section of the cavity can be above the drive section located at the bottom of the cavity or the drive section can be located intermediate two support sections.
[0048] Retaining means are provided on either the output drive shaft or in the cavity 315 or a combination of both to detachably retain the grinding cup so that grinding cup will not fly off during use but can still be easily removed or changed after use. As noted previously the specific means of connecting and retaining the drive connection member to the output drive shaft may vary to match any of the existing drive systems known in the prior art or any new standardized or customized drive systems developed. For example in the embodiment shown in FIG. 2 a groove 318 is provided in the wall 319 of cavity 315 into which an O-ring 320 is placed. The O-ring 320 will co-operate with the exterior surface of the output drive shaft to assist in retaining the grinding cup in place during use and reducing vibration and resonance. Additional O-rings on the output drive shaft will co-operate with the wall 319 of the bottom portion 317 of cavity 315 and O-ring 320 to retain the grinding cup in place during use. These grooves and O-rings are points of engagement which work to optimize the transfer of loads between the adapter and the output drive shaft.
[0049] In the embodiment shown, the drive connection member 303 is adapted to optimize the engagement or drive surfaces on the drive section 328 of the grinding cup with the corresponding contact surfaces on the output drive shaft to reduce vibration to thereby reduce rotor wear, as well as other potential associated wear to the grinding apparatus caused by vibration and/or resonance and to improve operational stability by optimizing and harmonizing the forces transferred between the rotor and grinding cup during operation including torsion (rotational) forces, axial (feed) forces and radial (varying side load) forces. Reduced vibration also improves operational stability, drive/contact surface wear/damage, wear/damage and/or deformation of materials in the drive and/or contact areas by optimizing and harmonizing the forces transferred between the rotor and grinding cup during operation including torsion (rotational) forces, axial (feed) forces and radial (varying side load) forces. In addition, substantially reducing vibration and/or resonance, minimizes the deterioration of the preferred built-in profile of the cavity in the grinding section.
[0050] To further reduce vibration and improve operational stability, drive/contact surface wear/damage, wear/damage and/or deformation of materials in the drive and/or contact areas by optimizing and harmonizing the forces transferred between the rotor and grinding cup during operation including torsion (rotational) forces, axial (feed) forces and radial (varying side load) forces, it is possible to utilize lighter weight materials such as metallic or non-metallic materials in the grinding member or drive connection member or to form part of the drive means or retaining means. Non-metallic materials, such as plastics, polymers or elastomeric material and the like, can be used in mating surfaces between the dive member and the drive connection member and or drive connection member and the output drive shaft or adapter. Non-metallic materials can be selected to provide anti-wear characteristics, provide anti-vibration characteristics or allow mating surfaces to be more forgiving when dirt is present, potentially reducing problems within the mating sections. Similarly the components of the grinding member and drive connection member can be made from metallic or non-metallic materials or a combination of both in order to facilitate use of alternative manufacturing methods such as injection moulding, casting, powder metallurgy etc to make some of the components at a lower cost.
[0051] The grinding cups of the present invention are intended to reduce manufacturing costs by standardizing components and reducing inventory on hand. However they also may have a number of features directed to (1) optimizing the drive surface on the drive means to prevent uneven wear and further reduce vibration to optimize the drive and/or contact surfaces on the drive means of a grinding cup relative to the corresponding drive and/or contact surfaces of the grinding apparatus rotor/adapter to prevent uneven wear and reduce vibration (2) reduce negative impact on wear/damage and/or deformation of materials in drive and/or contact areas (3) improving operational stability by optimizing/harmonizing the forces transferred between the rotor and grinding cup during operation including torsion (rotational) forces, axial (feed) forces and radial (varying side load) forces (4) minimizing operator exposure to sharp and/or protruding features when the grinding cup and rotor have engaged (5) substantially streamline/harmonize all contact surfaces including the combined outside geometry at the transition point between grinding cups and rotor/adapter and (6) reducing the mass of the grinding cups by reducing the outside and inside profile of the grinding cup and/or using lighter weight materials.
[0052] Having illustrated and described a preferred embodiment of the invention and certain possible modifications thereto, it should be apparent to those of ordinary skill in the art that the invention permits of further modification in arrangement and detail. For example the grinding cup may include an adapter to connect the grinding cup of one drive system to the output drive shaft of a different drive system. As an alternative to forming a grinding cup for attachment to the output drive shaft using known drive systems, the drive connection member can be a separate section of the output drive shaft. The drive connection member could be connected directly to the output drive shaft, by a threaded or other suitable detachable connection, that will provide proper alignment between components.
[0053] It will be appreciated that the above description related to the preferred embodiment by way of example only. Many variations on the invention will be obvious to those knowledgeable in the field, and such obvious variations are within the scope of the invention as described and claimed, whether or not expressly described. | The present invention provides a grinding member or connection to a drive connection member to form a grinding cup for grinding the hard metal inserts or working tips of drill bits (percussive or rotary), tunnel boring machine cutters (TBM) and raised bore machine cutters (RBM) to restore them to substantially their original profile, said grinding member having: a. a grinding section having top and bottom surfaces, a centrally disposed convex recess formed in the bottom surface of said grinding section having the desired profile to be ground; b. a support section adjacent the top surface of said grinding section; c. means to connect the grinding member to the drive connection member wherein the grinding member can be disconnected from the drive connection member when it becomes worn. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an embroidering apparatus mountable on a sewing machine bed.
This invention is an improvement upon the invention of U.S. patent application Ser. No. 323,453, filed on the same date, entitled "Embroidering Apparatus for Use with Sewing Machines", and commonly owned.
2. Description of the Prior Art
Known embroidering apparatus comprises a fixed rail mounting on a sewing machine frame, a movable rail extending in criss-cross relation to the fixed rail, and an embroidery frame movable back and forth and laterally along the fixed and movable rails. A piece of cloth, on which a pattern is drawn duplicating an original pattern, is placed under tension on the embroidery frame, which is manually moved around so as to allow a sewing needle as it moves up and down to follow the pattern on the piece of cloth. It is not an easy task to pattern a figure in detail after duplicating a model on the cloth as correctly as the operator desires, for there is always a tendency for the pattern to be drawn somewhat differently from the model pattern. Another disadvantage with the prior embroidering apparatus is that is is difficult to move the embroidery frame in order for the needle to pierce the cloth exactly at desired positions, resulting at times in embroidered works which are not patterned after the model.
Another type of embroidering apparatus comprises a tracing needle which traces a fixed original pattern while the tracing needle is moving with an embroidery frame. Such embroidering apparatus is disclosed in U.S. Pat. No. 2,894,468, issued July 14, 1959 to Walter Nohl, for example. The embroidery frame may be either movable back and forth and laterally along crossing rails, or supported on a pantograph mechanism of parallel links which is expansible and contractable for allowing back-and-forth and lateral movements of the embroidery frame. The tracing needle is attached to a rod extending from the embroidery frame for movement therewith. In operation, the rod is gripped at an end portion thereof adjacent to the tracing needle and moved so as to enable the latter to follow the original pattern. With this arrangement, it is not necessary to draw a pattern on a piece of cloth duplicating the original, and the patterning can be effected easily and reliably as the tracing needle follows the original while kept in contact therewith or closely thereto. However, since the tracing needle and the embroidery frame move in unison, leftward movement of the tracing needle causes the sewing needle to be located rightward in the embroidery frame and forward movement of the tracing needle causes the sewing needle to be located rearwardly in the embroidery frame, making an embroidered pattern look inverted. Such an inverted pattern renders it quite difficult for the operator to ascertain whether the original model is being followed accurately while in the embroidering operation. There has been known an apparatus having a mechanism for orienting an embroidered work in the same direction as the original pattern. Inclusion of such an additional mechanism makes the apparatus complex in construction. Furthermore, since the rod is relatively slender and flexible, it tends to flex due to frictional resistance between the cloth placed on the embroidery frame and a throat plate, with the results that movement of the embroidery frame will not correctly reflect that of the tracing needle, and hence the resultant embroidered pattern will not look much like the original pattern.
The prior embroidering apparatus as described above are designed to embroider a piece of cloth only with stitches in one and the same directions, and are unable to produce embroidery works with stitches in any different directions, such as a pattern of fur of an animal. To cope with this, there have been devised embroidering apparatus having an embroidery frame that is rotatable as well as movable back and forth and laterally to produce an embroidered pattern with varying stitches. One such embroidery apparatus is manually actuatable, while the other is electrically controllable. The former type is disclosed in U.S. Pat. No. 3,082,721, issued Mar. 26, 1963 to Luigi Bono, and the latter type is disclosed in U.S. Pat. No. 4,195,581, issued Apr. 1, 1980 to Naoki Ohara, for example. The manually operable apparatus has suffered from problems in that a pattern is required to be drawn on a piece of cloth after a model, a procedure which can produce a rough contour of the model but fails to transfer exactly the same pattern to the cloth, and hence the original pattern, the figure drawn on the cloth and the embroidered pattern are likely to look different. Furthermore, the operator should be trained and skilled sufficiently in rotating, moving back and forth, and moving laterally the embroidery frame or a support frame therefor at the same time. Otherwise, embroidering a pattern exactly after a model would not be possible. The electrically-operated embroidering apparatus comprises an actuator including three pulse motors for rotating, moving back and forth, and moving laterally an embroidery frame, and a control unit for electrically controlling the pulse motors. The embroidering apparatus is thus quite complex in structure and expensive to construct.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an embroidering apparatus for use with sewing machines which comprises a table for placing thereon an original pattern, an embroidery frame operatively connected to the table for back-and-forth and lateral movement therewith, and a fixed tracing needle oriented to the table, so that the table can be moved in order for the fixed tracing needle to follow the original pattern.
In one arrangement, the table and the embroidery frame may be movable back and forth and laterally by runners rollingly movably mounted on crossing rails, and the runners may be locked by stoppers on the rails against movement therealong.
The stoppers may comprise caps movably mounted on the rails and capable of sandwiching the runners therebetween against movement along the rails. Alternatively, the stoppers may be mounted on the runners and comprise cams angularly rotatably supported on the runners and actuatable by handle levers into pressing engagement with the rails for securing the runners to the rails.
The pantograph mechanism is advantageous in that if allows the apparatus to move more smoothly than the rail-mounted apparatus.
Another object of the present invention is to provide an embroidering apparatus for use with sewing machines which can produce embroidered works having varying stitches by rotating, moving back and forth, and moving laterally a table on which an original pattern is placed. Their angular velocities are the same at all times, and the tracing needle is directed toward the axis of rotation of the table when the sewing needle points at the center of rotation of the embroidery frame, so that the embroidery frame and the table are always in angular agreement irrespective of an angular position of an original pattern on the table. If the angular velocities of the table and the embroidery frame were different, they would rotate at different rates and shift embroidering stitches out of agreement with the original pattern. In addition, if the sewing and tracing needles were not spaced equidistantly from the respective axes of rotation of the table and the embroidery frame, the needles would describe arcs of different lengths on the table and the embroidery frame as they rotate through the same angle, resulting in an embroidered pattern different from the original pattern.
The table is preferably coupled by a power transmitting device to a support frame to which the embroidery frame is attached, though rotative power may be transmitted from the table directly to the embroidery frame by a power transmitting device such as a belt drive device, a gear drive device, or a friction drive device.
According to an embodiment of the present invention, a pair of guide rails are fixedly mounted on sides of a body which supports thereon a table and an embroidery frame, the guide rails being movably supported on runners secured to ends of another guide rail extending normally to the pair of guide rails. The latter guide rail is movably supported on a runner attached to a fixed member secured to a presser bar of a sewing machine.
The guide rail engaging the runner to which the fixed member is attached may be of a circular cross section and may be rotatably mounted on the runner, so that the body is angularly movable with respect to the fixed member.
According to still another embodiment, the body is connected to a member fixed to the presser bar through a pantograph mechanism comprising parallel links.
In the foregoing embodiments, a tracing needle is fixed to an end portion of a rod which is secured to the presser bar, a sewing machine frame, the guide rail or a fixed member secured to the presser bar.
According to still another feature, there is provided a locking device for stopping rotation of an embroidery frame which is rotatable and movable back and forth and laterally, allowing the embroidering apparatus to produce an embroidery work with stitches in one and the same directions or stitches in any different directions. The locking device is selectively movable between positions, one for allowing movement of and the other for disabling the embroidery frame, power transmitting device, or table. The braking device may comprise a roller pressable against or a pointed projection movable into biting engagement with the embroidery frame, power transmitting device, or table.
Still another feature of the present invention is that the embroidery frame can simply and easily be attached to or detached from the support frame.
The above and other objects, features and advantages of the present invention will become apparent from the following description when taken in conjunction with the accompanying drawings which show preferred embodiments of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary perspective view of a sewing machine equipped with an embroidering apparatus;
FIG. 2 is a plan view of the embroidering apparatus shown in FIG. 1 with fixed member secured to a presser bar;
FIG. 3 is a front elevational view of the embroidering apparatus;
FIG. 4 is a side elevational view of the embroidering apparatus with a belt, and a support frame shown partly in cross section;
FIG. 5 is an elevational view, partly in cross section, of a support frame rotatably supported by a modified structure;
FIG. 6 is a fragmentary plan view of a table and a support frame rotatably coupled through a gear drive;
FIG. 7 is a fragmentary plan view of a table and a support frame rotatably coupled through a friction drive;
FIG. 8 is a side elevational view of the embroidering apparatus with the fixed member attached to the presser bar in an inclined position;
FIG. 9 is an enlarged cross-sectional view of an embroidery frame attached to the support frame;
FIG. 10 is an enlarged cross-sectional view of a modified embroidery frame attached to the support frame;
FIG. 11A is an enlarged plan view of a locking device for the embroidery frame;
FIG. 11B is an enlarged cross-sectional view taken along line XIB--XIB of FIG. 11A;
FIG. 12A is an enlarged plan view of a locking device according to another embodiment;
FIG. 12B is an enlarged cross-sectional view taken along line XIIB--XIIB of FIG. 12A;
FIG. 13 is an enlarged plan view of a locking device according to still another embodiment;
FIG. 14 is an enlarged front elevational view of a runner secured by stoppers to a rail;
FIG. 15 is an enlarged front elevational view, partly broken away, of a runner secured by a different stopper to a rail;
FIG. 16 is a view of another runner secured by a stopper;
FIG. 17 is a plan view of an embroidering apparatus according to another embodiment;
FIG. 18 is a righthand side elevational view of the embroidering apparatus shown in FIG. 17;
FIG. 19 is a plan view of an embroidering apparatus according to another embodiment; and
FIG. 20 is a front elevational view of the embroidering apparatus shown in FIG. 19.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
As shown in FIG. 1, a sewing machine 20 comprises a bed 21 and a head 22 which supports a presser bar 23 and a needle 24. An embroidering apparatus according to the present invention is mounted on the bed 21, the embroidering apparatus being generally indicated at the reference numeral 25.
As illustrated in FIGS. 2 through 4, the embroidering apparatus 25 comprises a body 26 on which a circular table 27 is journalled for placing and fixing thereon an original pattern, and an annular support frame 28 is rotatably mounted. Each of the table 27 and the frame 28 has a peripheral groove 29 receiving therein an endless belt 30, or preferably a timing belt, which extends around the table 27 and the frame 28 for their rotation, or for transmitting rotative power from the table 27 to the support frame 28, the table 27 and the support frame 28 having the same diameter where the belt 30 engages them. The support frame 28 is rotatably mounted on the body 26 by a plurality of rollers 31 rotatably supported on the body 26 at spaced locations and held in engagement with the belt 30 disposed around the support frame 28.
According to another embodiment illustrated in FIG. 5, the support frame 28 is rotatably fitted in a cylindrical member 261 integral with the body 26. A holder 32 is preferably mounted on the body 26 and holds the support frame 28 at its upper surface to prevent the support frame 28 from being accidentally displaced upwardly. Rotative power may be transmitted from the table 27 to the support frame 28 by a gear drive device 30' (FIG. 6) or a friction drive device 30" (FIG. 7).
A pair of parallel rails 33, 33 is fixed to an upper surface on the body 26 and disposed one of each side of the support frame 28. A transverse rail 35 supports on ends thereof a pair of runners 34, 34 which are rollingly mounted on and support the rails 33, 33, respectively. The rail 35 is supported on a runner 37 secured to a fixed member 36 for rolling movement relative to the runner 37, the fixed member 36 embracing at an end thereof and being secured to the presser bar 23 by a set screw 38.
The body 26 is thus movable horizontally omnidirectionally, or in longitudinal directions of the rails 33, 35, across an extent which is large enough to cover the diameter of an embroidery frame (later described) mounted on the support frame 28. Conventional sewing machines have a sufficient space available for the support frame to move within the foregoing extent during embroidering operation. The embroidering apparatus 25 is oriented with respect to the sewing machine 20 such that the longitudinal axis of the apparatus 25 extending through the centers of the table 27 and support frame 28 is directed along the longitudinal direction of the bed 21. With such orientation of the embroidering apparatus 25, the operator can watch equidistantly the original pattern on the table 27 and an embroidery being formed in the embroidery frame with the needle 24 before him or her, resulting in a facilitated embroidering operation. In addition, the embroidering apparatus 25 thus directed on the sewing machine 20 allows unobstructed insertion and removal of a bobbin into and out of the sewing machine 20.
When attaching the fixed member 36 to the presser bar 23, it is required that the fixed member 36 lie parallel to the bed 21. Had the fixed member 36 been inclined with respect to the bed 21, the runners 34, the rail 33, and the body 26 would also be inclined with respect to the bed 21, causing a piece of cloth attached to the embroidery frame to be either spaced upwardly away from a throat plate with a resultant skip stitch, or pressed against the bed 21 and subjected to sluggish movement, which prevents the embroidering apparatus 25 from moving smoothly. In attaching the fixed member 36 to the presser bar 23, therefore, the fixed member 36 is positionally adjusted several times with respect to the presser bar 23 while the operator moves the embroidering apparatus around to see if it lies in a horizontal plane, a procedure which is quite tedious and time consuming, however.
To avoid such a complicated adjustment operation, the rail 35 may be of a circular cross section as shown in FIG. 8, and may be rotatably mounted on either the runner 37 or the runners 34. With this arrangement, the runners 34 are permitted to follow the rails 33 on the body 26 mounted on the bed 21 until the runners 34 lie parallel to the bed 21 even when the fixed member 36 extends at an angle to the bed 21. No positional adjustment is thus rendered necessary when the fixed member 36 is attached, as inclined, to the presser bar 23 at a slightly lowered position thereon, as illustrated in FIG. 8.
The fixed member 36 may be shorter than illustrated in FIG. 2 provided it can support the runner 37 and can be secured to the presser bar 23. The shorter fixed member 36 is advantageous in that the space taken up by the embroidering apparatus 25 can be smaller since the fixed member 36 and the runner 37 will not project beyond the peripheral edges of the body 26 when the body 26 is moved until the inner edge of the embroidery frame gets close to the needle 24.
A rod 41 is secured at one end to the fixed member 36 and has at the other end a tracing needle 40 directed toward the table 27. The tracing needle 40 is so positioned that it points to the center of rotation of the table 27 when the needle 24 is directed to the axis of rotation of the support frame 28.
As shown in FIG. 9, the support frame 28 is preferably made of synthetic resin and includes a plurality of attachment projections 44 circumferentially spaced from each other and each having in its upper surface a notch 43. The embroidery frame 45 comprises an inner frame member 45a and an outer frame member 45b, both made of synthetic resin, the inner frame member 45a having a plurality of flexible clips 47 of synthetic resin which positionally correspond respectively to the attachment projections 44 and include prongs 46 that can fit in the notches 43. the attachment projections 44 are engaged by the clips 47 to hold down the embroidery frame 45, and should have sufficient length to accommodate embroidery frames of various diameters.
When the embroidery frame 45 is to be attached to the support frame 28, a piece of cloth W as stretched is held against the inner frame member 45a or the outer frame member 45b, and the inner frame member 45a is fitted in the outer frame member 45b with the piece of cloth W sandwiched therebetween. Then, the assembled embroidery frame 45 is inserted into the support frame 28 until the former abuts against the attachment projections 44, and the embroidery frame 45 is turned until the clips 47 are brought into positional alignment with the attachment projections 44. The clips 47 are now pushed radially outwardly to force the prongs 46 into the notches 43. As an alternative, the support frame 28 has an attachment projection extending continuously along the entire internal edge of the support frame and having a notch in its surface, an arrangement which makes it possible to attach the embroidery frame to the support frame 28 in any desired angular relation to the latter.
When it is necessary to attach the embroidery frame 45 to or remove the same from the support frame 28 after the fixed member 36 has been secured to the presser bar 23 and the embroidering apparatus 25 has been mounted on the sewing machine 20, the presser bar 23 is first lifted to raise the embroidering apparatus 25 away from the bed 21, and then embroidery frame 45 is inserted or removed through a clearance formed between the bed 21 and the body 26 as elevated.
According to a modification shown in FIG. 10, an inner frame member 45a has in its upper surface a slot 49, and a support frame 28 has on its inner peripheral edge a plurality of attachment projections 44 or a single continuous attachment projection 44 supporting thereon a plurality of protuberances 50 or a continuous ridge 50 directed downwardly and forcibly inserted in the slot 49. Alternatively, the piece of cloth W may be pinned to the embroidery frame 45 in which case the latter may be of an integral structure and separate inner and outer frame members may be dispensed with.
Although not shown, the piece of cloth W may be retained in place by being forcibly sandwiched between the interfitting embroidery frame and the support frame. Such an arrangement requires no attachments to hold the embroidery and support frames together, but it is preferable that one of the embroidery and support frames has some means which engage the other so that the embroidery frame will not accidentally be displaced out of the support frame.
In operation of the embroidering apparatus 25, an original pattern is fixedly placed on the table 27 which is then supported by hand, and, as the sewing machine 20 operates, the table 27 is manually rotated and the body 26 is moved back and forth and laterally for causing the needle 40 to trace the pattern on the table 27. The embroidering apparatus 25 of the present invention can be operated with greater ease than conventional embroidering apparatus in which an embroidery frame needs to be rotated and moved to and fro in various directions.
The embroidering apparatus constructed can produce an embroidery work having stitches in any different directions by rotating the embroidery frame during operation. It is however difficult to embroider a piece of cloth with stitches in one and the same directions simply by holding the table by hand against rotation since the table is liable to turn when the body 26 is moved around.
To eliminate the above difficulty, a locking device for limiting rotation of the table may be employed. More specifically, as illustrated in FIGS. 11A and 11B, one of a pair of rollers 31 which engage the belt 30 between the table 27 and the support frame 28 is mounted for rotation on a pin 52 slidably received in a slot 54 in the body 26 and supporting a channel-shaped member 53 in which the roller 31 is rotatably disposed. An eccentric cam 55 is rotatably mounted on the body 26, and the channel-shaped member 53 is held at its back against the eccentric cam 55 under the tension of the belt 30. The eccentric cam 55 has a handle 56 which, when actuated, turns the eccentric cam 55 to move the channel-shaped member 53 and hence the roller 31 back and forth along the slot 54. When the channel-shaped member 53 is lifted upward by the cam 55 to cause the roller 31 to make the belt 30 tighter, the table 27 and the support frame 28 are fastened by the belt 30 to the point where they are prevented from rotation. Retraction of the channel-shaped member 53 permits the belt 30 to get loosened, whereupon the table 27 and the support frame 28 are rendered rotatable. Preferably, the channel-shaped member 53 may have on its back a ridge, and the peripheral cam may have in its cam surface grooves receptive therein of the ridge when the roller 31 is pushed forward and backward, respectively. With such a locking device, the table 27 and the support frame 28 can selectively be locked against rotation or rendered freely rotatable.
FIGS. 12A and 12B illustrate a locking device according to another embodiment in which the body 26 supports thereon a pair of spaced projections 59 having holes through which extends a threaded rod 60 secured at one end thereof to a channel-shaped member 53 in which a roller 31 is rotatably mounted. A dial or adjustment nut 58 is threaded on the rod 60 and located between the projections 59. Turning the dial 58 causes the channel-shaped member 53 to move back and forth on the body 26, whereupon the roller 31 tightens or loosens the belt to lock or free the table 27 and the support frame 28. The roller 31 can be moved back and forth for small intervals to enable fine adjustment of tension of the belt.
The roller 31 may be rotatably mounted on an end of a bell crank or lever pivotally mounted at its center on the body 26. The other end of the bell crank or lever can be angularly moved to shift the roller 31 in order to increase or reduce the tension of the belt, and should preferably be able to be held at a desired position in a manner well known in the art.
FIG. 13 shows a locking device for locking a table and a support frame which are operatively connected by a gear drive device for transmitting rotative power from the table to the support frame. The locking device comprises a bolt 63 extending threadedly through a projection 62 mounted on the body, a ratchet 64 rotatably supported on the body, and a spring 65 resiliently held against an end of the bolt 63 for biasing the ratchet 64 toward the projection 62. Rotation of the bolt 63 for axial movement thereof through the projection 62 causes the ratchet 64 to move into and out of engagement with a transmission gear 66, thus allowing the support frame to be fixed and rotatable, respectively.
The embroidering apparatus 25 is movable freely in a desired direction due to combined motion of the body 26 that travels along the directions in which the rails 33, 35 extend. There are occasions in which the piece of cloth should be embroidered with stitches along a straight line by moving the embroidering apparatus 25 only in a back-and-forth direction or in a lateral direction. However, the apparatus 25 tends to move around in undesired directions even if the operator attempts to move the embroidery frame rectilinearly in one direction, resulting in a failure to embroider the piece of cloth along a desired straight-line direction.
The above difficulty can be eliminated by securing the runner to the rail with a stopper at any desired position on the rail. One such stopper comprises a cap 69 mounted slidably on a rail 68 as shown in FIG. 14, the cap 69 being of a resilient tubular configuration formed of rubber or plastics. Two of such caps 69 are fitted over the rail 68 and held against opposite ends of a runner 70 to sandwich and keep the latter in a desired position on the rail 68 against movement therealong.
FIG. 15 illustrates an alternative embodiment in which a runner 72 has a cam block 74 rotatably disposed therein and having a handle lever 73 projecting out of the runner 72, the cam block 74 preferably comprising a resilient eccentric cam made of rubber of plastics. The runner 72 is to be fixed in position on a rail 75, when the handle lever 73 is turned until the cam block 74 is pressed against the rail 75. The cam block 74 may be replaced with a pointed projection which can be turned into biting engagement with the rail 75.
According to still another embodiment shown in FIG. 16, a runner 77 has an arm 78 projecting therefrom and through which threadedly extends a threaded rod 80 directed to a rail 79 and having a handle 81 secured thereto for rotating the rod 80 about its own axis. The runner 77 can be fixed in position by turning the handle 81 to advance the threaded rod 80 until its end is pressed against the rail 79. A resilient cap 82, preferably of synthetic resin or rubber, is mounted on the end of the threaded rod 80 to prevent the latter from biting into and hence damaging the rail 79.
With the runners thus secured in position, the embroidering apparatus 25 is prevented from accidentally sliding and breaking the sewing needle 24 when the sewing machine is tilted for insertion and removal of the bobbin or is carried around.
According to another embodiment shown in FIGS. 17 and 18, an embroidering apparatus comprises a body 101 on which there is mounted a rail 102 supported at ends thereof on a pair of supports 103, 103 fixed to the body 101, the rail 102 being spaced upwardly from the body 101. The runner assembly 104 comprises a pair of upper and lower runners 104b, 104a, the lower runner 104a supporting the rail 102 so as to allow the latter to be movable relatively to the lower runner 104a. A rail 105 which extends at a right angle to the rail 102 is movably supported on the upper runner 104b, and is secured at one end thereof to the presser bar 23 of the sewing machine by a set screw 106 so as to lie parallel to the bed 21 of the sewing machine. The body 101 supports thereon a circular table 107 and an annular support frame 109 with an embroidery frame 108 attached thereto, the table 107 and the support frame 109 being connected by an endless belt 110 disposed therearound. A rod 112 is fixed endwise to the rail 105 and has a tracing needle 111 disposed over and oriented to the table 107. In operation, the embroidery frame 108 can be rotated and moved around by rotating and moving around the table 107, or by rotating the table 107 and moving the body 101 with a grip handle 113 attached to the body 101. The embroidering apparatus shown in FIGS. 17 and 18 is move advantageous than the foregoing embroidering apparatus 25 in that only two rails 102, 105 are required and no separate fixed member is needed.
FIGS. 19 and 20 illustrate an embroidering apparatus according to another embodiment. The apparatus comprises a body 130 operatively coupled by a pantograph mechanism 133 to a fixed member 132 secured to the presser bar 23 by a set screw 131. The pantograph mechanism 133 is extensible and retractable to allow back-and-forth and lateral movement of the body 130. The pantograph mechanism 133 comprises a disk-shaped intermediate member 135 and two sets of parallel links 136 operatively connected between the intermediate member 135 and the fixed member 132 and between the intermediate member 135 and the body 130, respectively. Pantograph mechanisms of known constructions may be used in place of the illustrated pantograph mechanism. The body 130 supports thereon a table 137 and a support frame 139 to which an embroidery frame 138 is attached, there being an endless belt 140 disposed around the table 137 and the support frame 139 for transmitting rotative power from the former to the latter. A rod 143 with a tracing needle 142 attached is supported on the fixed member 132, the tracing needle 142 being directed toward the table 137.
Although certain preferred embodiment have been shown and described in detail, it should be understood that many changes and modifications may be made therein without departing from the scope of the appended claims. | An embroidering apparatus for use with a sewing machine has a body supported on a bed and movable back and forth and laterally along guide rails extending perpendicularly to each other. A table and a support frame to which an embroidery frame is attachable are mounted on the body for movement therewith. A fixed tracing needle is oriented to the table on which an original pattern is to be placed. In operation, the table can be manipulated to permit the tracing needle to follow the original pattern on the table while the latter is being moved around. For certain pattern configurations locking or stop devices are employed for selectively locking the table and support frame against rotation or for constraining the frame to only rectilinear movement. | 3 |
CROSS REFERENCES TO RELATED APPLICATIONS
U.S. patent applications Ser. No. 379,684 by Winbow et al., filed May 19, 1982, Ser. No. 395,449 by Winbow et al., filed July 6, 1982, Ser. No. 440,140 by Winbow et al., filed Nov. 8, 1982, and Ser. No. 454,925 by Winbow et al., filed Jan. 3, 1983, all assigned to Exxon Production Research Company, relate to the general field of this invention.
BACKGROUND OF THE INVENTION
This invention relates to acoustic well logging in general and more particularly to acoustic compressional wave well logging and acoustic shear wave well logging.
Acoustic well logging has been generally accepted as a method for obtaining information about subterranean formations surrounding wells or boreholes. The applications of acoustic well logging include the determination of formation lithology, density, and porosity, the conversion of seismic time sections to depth sections, the determination of elastic constants of subsurface materials, and the detection of fractures and provision of information about their orientation.
In acoustic well logging it is customary to measure the compressional wave or shear wave velocity of subterranean formations surrounding boreholes. Compressional waves are also known as P-waves. Shear waves are also known as S-waves. A conventional P-wave velocity logging system includes a cylindrical logging sonde suitable for suspension in a borehole liquid, a source connected to the sonde for generating P-waves in the borehole liquid and two detectors connected to the sonde and spaced apart from the P-wave source for detecting P-waves in the borehole liquid. A compressional wave in the borehole liquid generated by the source is refracted in the earth formation (the phrase "earth formation" will be used throughout this specification to denote any subterranean formation, and will not be used in a narrow sense to denote any particular type of subterranean formation) surrounding the borehole. It propagates through a portion of the formation and is refracted back into the borehole liquid and detected by two detectors spaced vertically apart from each other and from the P-wave source. The ratio of the distance between the two detectors to the time between the detections of the P-wave by the two detectors yields the P-wave velocity of the formation. The P-waves in the borehole liquid caused by refraction of P-waves back into the borehole may be called the P-wave arrival.
The compressional wave velocity of the earth formation surrounding a borehole frequently varies with radial distance from the borehole. Several factors can give rise to such an effect, including drilling damage to the formation, penetration of the formation adjacent to the borehole by borehole drilling fluids, and in the Arctic, melting of permafrost near the borehole.
The part of the formation that has been so damaged, penetrated, or melted is known as the invaded zone, and the remaining part of the formation which has not been so affected, the virgin formation. Thus, the borehole is surrounded by the invaded zone which in turn is surrounded by the virgin formation. The compressional wave velocity of the virgin formation is usually different from that of the invaded zone. It is well known that compressional wave velocity logging of the virgin formation will yield information helpful for determining the porosity, rock lithology and density of the virgin earth formation.
The conventional P-wave logging source is symmetrical about the logging sonde axis. The P-waves generated by a conventional symmetrical source do not penetrate deeply into the earth formation surrounding the borehole. The depth of penetration of the P-wave arrival depends on the distance or spacing between the P-wave source and the detectors: the greater the source-detector spacing, a greater part of the P-wave energy refracted back into the borehole and detected will have penetrated deeper. With the spacing of six to ten feet commonly used in conventional P-wave logging, most of the energy of the P-waves generated by the source and detected by the detectors frequently does not penetrate beyond the invaded zone and only a small part of the P-wave energy reaches the virgin formation. The P-waves that reach and travel in the virgin formation typically will have smaller amplitudes than will the P-waves that do not penetrate beyond the invaded zone so that their arrivals may be masked by the arrivals of the P-waves that do not penetrate beyond the invaded zone. Therefore, where the source-detector spacing does not exceed the conventional spacing of six to ten feet, it may not be possible to use a symmetrical conventional source to log the P-wave velocity of the virgin formation. The source-detector spacing may be increased to increase the penetration of the P-waves. Increasing the source-detector spacing will, however, reduce the signal strength of the P-wave arrival. The attenuation of the P-waves traveling in the formation increases with the distance they travel in the formation. Thus, if the source-detector spacing is increased, the P-wave arrivals detected will be weaker and the resulting P-wave log may have a poor signal-to-noise ratio. It is thus desirable to increase the penetration of the P-waves without increasing the source-to-detector spacing.
Asymmetric compressional wave sources have been developed for logging the shear wave velocity of an earth formation. In such asymmetric sources, the source generates in the borehole fluid a positive pressure wave in one direction and a simultaneous negative pressure wave in the opposite direction. The interference of the two pressure waves produces a shear wave which is refracted in the earth formation. This type of asymmetric source is disclosed by European patent application Ser. No. 31989 by Angona et al., U.S. Pat. No. 3,593,255 to White, issued July 13, 1971, and U.S. Pat. No. 4,207,961 to Kitsunezaki, issued June 17, 1980.
Angona et al. discloses a bender-type source which comprises two circular piezoelectric plates bonded together and attached to a logging sonde by their perimeters. When voltage is applied across the two piezoelectric plates, the center portion of the circular plates will vibrate to create a positive compressional wave in one direction and a simultaneous negative compressional wave in the opposite direction. The two compressional waves will interfere to produce a shear wave in the earth surrounding the borehole. The bender-type source disclosed by Angona et al., will have a limited frequency range. It is specified in Angona et al., that the apparatus disclosed therein is capable of generating an acoustic signal having frequency components in the range of about 1 to 6 kHz, a frequency range in which the amplitude of the shear waves generated and refracted in the formation will likely be significantly greater than that of the P-waves generated and refracted in the formation, and thus a frequency range too low for compressional wave logging in most formations.
White discloses an asymmetric source comprising two piezoelectric segments each in the shape of a half hollow cylinder. The two segments are assembled to form a split cylinder. The two segments have opposite polarization and electrical voltage is applied to each segment, causing one segment to expand radially and simultaneously causing the other segment to contract radially, thereby producing a positive compressional wave in one direction and a simultaneous negative compressional wave in the opposite direction. The two compressional waves will interfere to produce a shear wave in the earth formation adjacent to the borehole. Such shear wave propagates along the borehole and is detected by a pair of transducers positioned substantially directly above or beneath the piezoelectric segments of the source. The White apparatus "accentuates" the shear waves and virtually eliminates the faster-traveling compressional waves generated and detected thereby. White does not disclose or suggest apparatus generally suitable for compressional wave logging. Nor does White disclose or suggest any method suitable for acoustic velocity logging of the virgin formation surrounding a borehole.
In Kitsunezaki, coils mounted on a bobbin assembly are placed in the magnetic field of a permanent magnet and current is passed through the coils to drive the bobbin assembly. The movement of the bobbin assembly ejects a volume of water in one direction and simultaneously sucks in an equivalent volume of water in the opposite direction, thereby generating a positive compressional wave in one direction and a simultaneous negative compressional wave in the opposite direction. Kitsunezaki's asymmetric source, however, cannot be driven at high frequencies or with sufficient power required for compressional wave logging in most formations. Also it cannot operate at great depths or under great pressures.
In another type of asymmetric shear wave logging source, instead of coupling the source to the borehole wall through the medium of the borehole fluid, the source is either coupled directly to the borehole wall or through mechanical means such as mounting pads. Such shear wave logging sources are disclosed in U.S. Pat. No. 3,354,983 to Erickson et al., issued Nov. 28, 1967, and U.S. Pat. No. 3,949,352 to Vogel, issued April 6, 1976.
SUMMARY OF THE INVENTION
The method and apparatus of this invention are for logging the compressional wave velocity, or the shear wave velocity, of the virgin earth formation surrounding a borehole but separated from the borehole by an invaded zone and for logging the radius of such invaded zone. The apparatus of this invention comprises a housing adapted to be raised and lowered into a borehole, signal generating means in the housing for transmitting a 2 n -pole acoustic wave (the multipole nomenclature used throughout this specification is explained below in the first paragraph of the Description of the Preferred Embodiment) through the virgin earth formation surrounding a borehole, where n is an integer greater than zero, and signal detecting means connected to the housing longitudinally spaced a sufficient distance along the borehole from the signal generating means for detecting the arrival of such 2 n -pole acoustic wave.
The compressional wave logging method of the invention comprises transmitting a 2 n -pole compressional wave through the virgin earth formation surrounding a borehole, where n is an integer greater than zero, and detecting the 2 n -pole compressional wave arrival at at least one point longitudinally spaced along the borehole from the point of transmission. If the compressional wave arrival is detected at two points, the time lapse between the detections at the two points is measured to determine the compressional velocity of the virgin formation surrounding the borehole. If the 2 n -pole wave arrival is detected at only one point, the time lapse between transmission and detection is measured to determine the compressional wave velocity of the virgin formation. The latter method is more difficult to perform and much less accurate. In either case, the compressional wave velocity of the earth formation preferably is measured repeatedly with successively increasing source-detector spacings, until the compressional wave velocities measured in two consecutive measurements are substantially the same. That substantially constant measured velocity will be the compressional wave velocity of the virgin formation. Where the compressional wave velocities of the invaded zone and virgin formation are known, the minimum source-detector spacing which results in such substantially constant measured velocity may be used to determine the radius of the invaded zone.
The shear wave logging method of the invention is identical to the compressional wave velocity logging method except that 2 n -pole shear waves (rather than 2 n -pole compressional waves) are transmitted through the virgin earth formation and detected to determine the shear wave velocity of the virgin formation.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates three ray paths of acoustic waves generated by a multipole source. One ray path indicates an acoustic wave propagating in the invaded zone of the earth formation surrounding a borehole, another ray path indicates an acoustic wave propagating through and refracted by the virgin formation surrounding the invaded zone, and the third ray path indicates an acoustic wave reflected from the invaded zone-virgin formation interface.
FIG. 2 is a simplified, partially schematic and partially perspective view of a quadrupole compressional wave logging device illustrating the preferred embodiment of this invention.
FIG. 3 is a cross-sectional view of the preferred embodiment of the quadrupole compressional wave source illustrated in simplified form by FIG. 2, taken on a plane containing the logging sonde axis.
FIG. 4 is a simplified, partially perspective and partially schematic view of the quadrupole compressional wave logging device of FIG. 2, illustrating the orientation of the detectors relative to that of the quadrupole source and the electrical connections to the source and detectors.
FIG. 5 is a cross-sectional view of a quadrupole compressional wave logging source illustrating an alternate embodiment of this invention.
FIG. 6 is a cross-sectional view of an octopole compressional wave logging source illustrating still another embodiment of this invention.
FIG. 7 is a cross-sectional view of an octopole compressional wave logging source illustrating still another embodiment of this invention.
FIG. 8 is a cross-sectional view of a dipole compressional wave logging source illustrating a further alternate embodiment of this invention.
FIG. 9 is a cross-sectional view of a dipole compressional wave logging source illustrating yet another alternate embodiment of this invention.
FIG. 10 is a cross-sectional view of the quadrupole compressional wave logging source of FIG. 3, taken along line 10--10.
FIG. 11 is a graph schematically illustrating the variation of the compressional wave velocity measured by the apparatus of the invention as the source-detector spacing increases.
FIG. 12 is a graph schematically illustrating the variation in the expected arrival times, respectively, of the refracted arrival P v from the virgin formation, the refracted arrival P i from the invaded zone, and the reflected arrival R from the invaded zone-virgin formation interface, as the thickness of the invaded zone increases.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The multipole nomenclature is based upon consecutive powers of two, that is, 2 n , n being an integer and n=1, 2, 3 and on indefinitely. Thus, the multipoles include the dipole (n=1), the quadrupole (n=2) and the octopole (n=3). The nomenclature for higher order multipoles is based upon 2 n with n=4, 5, 6 and so on indefinitely. The multipoles do not include the monopole (n=0).
FIG. 1 illustrates three ray paths of acoustic waves generated by an an acoustic source 10 and one of the detectors D1 of a detector array 12. The acoustic wave velocities of the invaded zone may increase continuously with increasing distance from the borehole because of the different degrees of penetration of the borehole liquid into the invaded zone or damage near the borehole. The ray paths of the acoustic waves in the invaded zone will be curved, substantially as shown in FIG. 1, when the acoustic wave velocity of the invaded zone so depends on the distance from the borehole. For simplicity, FIG. 1 will be discussed below under the assumption that the acoustic waves are P-waves. It should be understood that such discussion is equally applicable in the case where the acoustic waves are S-waves.
In addition to traveling along the indicated ray paths, P-waves generated by source 10 also travel in the regions on both sides of each ray path: the region closer to the borehole and the region farther into the invaded zone. Those P-waves traveling in the invaded zone may be called Pi and those travelling in the virgin formation Pv. In addition to the refracted arrivals Pi and Pv, there is shown another early arrival, R, resulting from the reflection at the invaded zone-virgin formation interface. However, it is always the case that either Pi or Pv (or both) arrive at detector D1 before R. For a monopole P-wave much of the energy detected by array 12 does not penetrate beyond the invaded zone so that Pv may be small or at best comparable in amplitude compared to Pi. Therefore, it will be difficult to distinguish the Pv arrival detected from the Pi arrival detected so as to determine the P-wave velocity in the virgin formation.
The applicants have discovered that, when generated with the same source-detector spacing, the peak energy of a dipole P-wave penetrates the earth deeper than that of a monopole P-wave, and the peak energy of a quadrupole P-wave penetrates deeper than that of a dipole P-wave. In other words, as compared to the monopole P-wave, a greater percentage of the energy of the dipole P-wave will travel in the virgin formation. For the quadrupole P-wave, an even higher percentage of the energy travels in the virgin formation so that Pv has intensity significantly greater than Pi and the P-wave velocity of the virgin formation may be logged by logging Pv.
The applicants have also discovered that for the same source-detector spacing, the percentage of energy traveling in the virgin formation will increase with the order of the multipole P-wave source. Thus a higher order P-wave source will have a better Pv to Pi ratio. However, the 16-pole and other higher order multipole P-wave sources will generally generate P-waves weaker than those generated by the quadrupole and octopole P-wave sources. Therefore, the quadrupole and octopole P-wave sources are the preferred P-wave sources for logging the virgin formation.
FIG. 2 is a partially schematic and partially perspective view of an acoustic logging system illustrating the preferred embodiment of the apparatus of this invention. A logging sonde 20 is adapted to be lowered into or removed from a borehole 22. To initiate logging, sonde 20 is suspended into a liquid 24 contained in borehole 22 which is surrounded by an earth formation 26 comprising an invaded zone immediately adjacent to liquid 24 and a virgin formation surrounding the invaded zone (the invaded zone and virgin formation of earth formation 26 are not shown in FIG. 2). For ease of assembly, operation and repairs, logging, sonde 20 comprises a number of hollow cylindrical sections. The top section 32 contains a quadrupole P-wave logging source 10 and contains windows 34 which allow the P-waves generated by source 10 to propagate readily therethrough into the borehole liquid. Although four windows 34 are shown, section 32 may have more or less than four of such windows. Sections 36 and 38 contain, respectively, the first two detectors D1 and D2 of the detector array 12 and section 40 contains the last detector Dn of array 12. Other sections containing the remainder of the array are not shown or are only partly shown in FIG. 2.
Section 42 is a spacer section separating section 32 and section 36. The source-detector spacing may be adjusted by using such a spacer section of the appropriate length or by using more or fewer spacers to separate the source and the detectors. Alternatively, the effective source-detector spacing may be increased by providing an array of detectors, such as array 12 of FIG. 2, and selectively recording the arrivals detected by individual detectors or pairs of detectors positioned at increasing distances from the source.
Each section which contains a detector of array 12 has windows (such as windows 46, 48 and 50 of FIG. 2) through which the refracted P-waves from earth formation 26 may reach array 12.
Source 10 is connected to a firing and recording control unit 62 through a switch 64. The P-waves detected by array 12 are fed via a cable containing wires 66 to a switch 68, a band pass filter 70, an amplifier 72 and a time interval unit 74.
In a manner explained below the firing and recording control unit 62 is used to fire source 10 which produces a quadrupole P-wave in formation 26. The quadrupole P-wave arrival is detected by detectors D1 through Dn of detector array 12, which transform the acoustic signals recorded into electrical signals. The signals are fed to filter 70 through switch 68 whose function will be described below. The electrical signals are filtered by filter 70 and amplified by amplifier 72. The time interval between the detections by adjacent detectors may then be stored or displayed as desired in unit 74.
When a given dipole P-wave or a higher order P-wave is transmitted into a formation the arrival times of the refracted P-wave signals at the detectors will vary with the thickness of the invaded zone. FIG. 12 illustrates schematically the variation of the expected arrival times of the refracted arrivals, Pv and Pi, and the reflected arrival R as the thickness of the invaded zone increases. The thickness of the invaded zone is equal to the difference between r 2 , the outer radius of the invaded zone, and r 1 , the radius of the borehole. The hyperbolic curve representing the arrival times of reflected arrival R is tangent to the straight line curve representing the arrival times of Pv when the thickness of the invaded zone is equal to a critical thickness
r*=(z/2)(((Cv/Ci)-1)((Cv/Ci)+1)).sup.1/2,
where z is the source-detector spacing, Cv is the P-wave velocity in the virgin formation, and Ci is the P-wave velocity in the invaded zone. The applicants have found that for a considerable range of invaded zone thickness values near r*, refracted arrival Pv and reflected arrival R arrive at times differing by less than 1%, so that R will effectively reinforce the detected amplitude of Pv. The maximum amplitude of reflected arrival R occurs when the thickness of the invaded zone is equal to r*. Only when the thickness of the invaded zone is significantly greater than r* is the amplitude of reflected arrival R sufficiently diminished so that Pi is the first significant arrival.
Increasing the source-detector spacing will increase the depth of penetration of the P-wave energy into the invaded zone. If it is uncertain whether the arrival detected is that of Pi or Pv, the preferred method for distinguishing between the Pi and Pv arrivals involves plotting the velocity of the arrival against the source-detector spacing z as shown in FIG. 11. At small source-detector spacings the velocity logged will depend on the source-detector spacing z, for reasons to be discussed below. When the source-detector spacing reaches a certain critical spacing z*, the velocity logged approaches a constant. This constant velocity is substantially equal to Cv, the P-wave velocity in the virgin formation. The critical spacing, z*, is the spacing at which the dominant portion of the P-wave energy reaches the invaded zone-virgin formation interface.
The critical spacing, z*, may be determined by plotting the P-wave velocity measured against the source-detector spacing z, as in FIG. 11. The P-wave velocity to be plotted is calculated by dividing the distance between two detectors by the time interval between the detections of the P-wave arrival by the two detectors. lf the source-detector spacing is sufficiently small so that the P-wave never penetrates to the virgin formation, the entire ray path between the source and the detector is curved and the difference between the two ray path lengths is less than the distance between the two detectors. Thus, where the P-wave ray path never reaches the virgin formation, the P-wave velocity calculated in accordance with the above approximation tends to overestimate the actual P-wave velocity. When the source-detector spacing is increased sufficiently for the P-wave ray path to reach the virgin formation, the P-wave velocity measured will be a good approximation of the P-wave velocity in the virgin formation. Such minimum source-detector spacing is the critical spacing, z*. When the source-detector spacing is increased to beyond the critical spacing, the P-wave velocity measured will be substantially constant, thus determining the point in FIG. 11 beyond which the P-wave velocity measured is substantially constant.
The apparatus of FIG. 2 may also be used to determine the depth of invasion, D, surrounding the borehole by exploiting the following relationship:
d=(z/2)(((Cv/Ci)-1)((Cv/Ci)+1)).sup.1/2
where z is the source-detector spacing; d is the penetration depth of a P-wave into the formation; Cv is the P-wave velocity in the virgin formation; and Ci is the P-wave velocity in the invaded zone. The depth of penetration of the P-wave is equal to D, the depth of invasion, when the P-wave penetrates the invaded zone to reach the interface between the invaded zone and the virgin formation. Thus, if the critical spacing z* and P-wave velocities in the invaded zone and the virgin formation are known, the depth of invasion D may be calculated from the formula above.
The above discussion regarding P-wave velocity logging and the propagation of P-waves in the invaded zone and virgin earth formation surrounding a borehole applies equally to S-wave velocity logging and the propagation of S-waves. The methods disclosed herein are thus applicable in the context of S-wave velocity logging as well as in the context of P-wave velocity logging.
The seismic energy radiated by the logging sonde apparatus disclosed herein may be divided into two categories: Es, the energy radiated in the form of shear waves and Ep, the energy radiated in the form of compressional waves. The ratio of Ep to Es will depend on the frequency spectrum of the seismic radiation generated by the apparatus. The apparatus disclosed herein thus may be suitable for S-wave velocity logging as well as for P-wave velocity logging. For efficient compressional wave logging, it is desirable that the frequency range of generated radiation be that which maximizes the ratio of Ep to Es. This preferred frequency range will depend on the velocity of compressional waves in the earth formation to be logged. The applicants have found that for P-wave logging, where the compressional wave velocity in the formation is (a) thousand feet per second, the frequency range of radiation generated by the apparatus of this invention will desirably contain the frequency (a)(10/d)kHz, where d is the diameter of the borehole in inches.
Operation of the multipole seismic source of the present invention at frequencies significantly lower than (a)(10/d) kHz will result in the generation of a relatively strong shear wave signal and a relatively weak compressional wave signal. The applicants have discovered that the apparatus of the present invention may desirably be operated in such low frequency range for efficient S-wave velocity logging. Operation in such low frequency range will enable the relatively strong shear wave signal to penetrate far into the formation away from the borehole. With sufficiently large source-detector spacing, the shear wave velocity of the virgin formation may thus be logged.
The preferred method for logging the P-wave velocity of a virgin formation using the apparatus disclosed herein involves generating a broad band signal which is refracted through the virgin formation, detected by detectors D1 through Dn and fed through band pass filter 70. For P-wave logging, band pass filter 70 is chosen to filter the detected signal so that the recorded P-wave Pv arrivals have large amplitude relative to the recorded shear wave arrivals. For S-wave logging, band pass filter 70 is chosen to filter the detected signal so that the recorded shear wave arrivals have large amplitude relative to the recorded P-wave arrivals.
FIGS. 3 and 10 illustrate in more detail the preferred embodiment of the apparatus of this invention. FIG. 3 is a cross-sectional view of the preferred embodiment of the quadrupole compressional wave logging source illustrated in simplified form by FIG. 2, taken on a plane containing the logging sonde axis. FIG. 10 is a view taken along line 10--10 of FIG. 3 showing a cross-section of the quadrupole source on a plane perpendicular to the axis of the logging sonde.
Source 10 of FIG. 10 comprises four substantially similar sectors (or "members") 102, 104, 106, 108 of a radially polarized piezoelectric hollow cylinder arranged substantially coaxial with and equidistant from the sonde axis. Sectors of different cylinders with different radii may also be used. It will be appreciated that such four sectors may be used even if they are not coaxial with the sonde axis provided that their axes are substantially parallel to the sonde axis and that they are so oriented that the sonde axis is on the concave side of each sector. Such a configuration may be achieved by moving the four sectors 102, 104, 106, 108 of FIG. 10 radially away from the sonde axis by different distances. The cyclic order 102, 104, 106, 108 of the four sectors in FIG. 10 defines the relative positions of the four sectors. Since the order is cyclic, any one of the following cyclic orders may also be used to arrive at the same relative positions: 104, 106, 108, 102; 106, 108, 102, 104; and 108, 102, 104, 106. While the four sectors are preferably substantially evenly spaced around the sonde axis as shown in FIG. 10, it will be understood that configurations in which the four sectors are not evenly spaced around the sonde axis may also be used and are within the scope of this invention. Interchanging two sectors oppositely situated, such as 102 with 106 or 104 with 108, also will not affect the operation of the source of FIG. 10.
Source 10 need not comprise four sectors of a hollow cylinder as shown in FIG. 10 but may comprise members of any shape or size so long as their centroids are located relative to one another in a manner described below and they generate pressure waves in a manner similar to that of the sectors in FIG. 10 described earlier. The centroid is defined in the American Heritage Dictionary of the English Language, 1978, Houghton Mifflin Co., Boston, Mass. as the center of mass of an object having constant (i.e., uniform) density. If the object has varying density, the centroid of such object may be defined as the point which would be the centroid of such object if such object were of constant density.
The four members (first, second, third and fourth members) of any shape or size are so connected to a housing that in a quadrilateral, the four corners of which are defined by the centroids of the first, second and third members and the normal projection of the centroid of the fourth member on the plane defined by and containing the centroids of the first, second and third members, the four angles of the quadrilateral are each less than 180°. Preferably the centroids of the four members are coplanar and form the four corners of a square. Preferably, the plane containing the centroids is perpendicular to the borehole axis. If the four members are small so that they become essentially point pressure wave sources, then the four pressure waves are generated substantially at four points which are spatially located in the same manner as the centroids of the four members.
Referring back to the preferred embodiment shown in FIG. 10, substantially the same electrical pulse may be applied across the cylindrical surfaces of each of sectors 102, 104, 106, and 108 substantially simultaneously such that the pulses supplied to any two adjacent sectors are opposite in polarity. This arrangement is illustrated in FIG. 10. With such an arrangement, if one sector is caused by the electrical pulse to expand radially then the two adjacent sectors will contract radially and vice versa. If the four sectors are polarized radially outward then the directions of expansion and contraction will be as illustrated by hollow arrows in FIG. 10. During contraction of a sector its entire inner cylindrical surface will move inward; during its expansion its entire outer cylindrical surface will move outward. It should be appreciated that the polarization of the four sectors may be radially inward, opposite to that shown in FIG. 10. In such case, the directions of expansion and contraction caused by electric pulses of the polarity indicated in FIG. 10 will be opposite to those illustrated by the hollow arrows in FIG. 10. The substantially simultaneous expansion and contraction of the four sectors will generate a quadrupole P-wave in borehole liquid 24 of FIG. 2 which is then transmitted into earth formation 26 and detected by array 12 as described above. Operated in the manner described above in reference to FIG. 10, source 10 may be said to be in the quadrupole mode.
The four piezoelectric members 102, 104, 106, 108 of source 10 of FIGS. 3 and 10 may be connected to the logging sonde 20 in a manner most easily understood by reference to FIG. 3. Pistons 83 and 84 are of such diameters that they fit snugly into logging sonde 20. Pistons 83 and 84 have threaded recesses, 85 and 86 respectively, and the two pistons may be connected by a piston rod 114, the two ends of which are threaded and are of such sizes that they may be screwed into recesses 85 and 86 of pistons 83 and 84. To assemble source 10, piston rod 114 is inserted into an annular body of backing material 112 and the four members 102, 104, 106, 108 are placed on the outer cylindrical surface of body 112 so that they are substantially coaxial with the piston rod 114. Body 112 preferably is made of a backing material with good damping qualities to damp out the reverberations of the four members so that the four pressure wave trains generated by the four members are short in duration. Two annular rings of packing material 80 and 82 fit snugly over the four members and body 112 to keep the members in place. Piston rod 114 and pistons 83 and 84 are then assembled as described earlier and the entire assembly is inserted into the logging sonde 20. Logging sonde 20 has four windows distributed around its circumference near source 10, and enclosed sealingly by four rubber membranes 87, 88, 89 and 90. Although four windows are shown in FIG. 10, sonde 22 may have more or less than four windows.
The four rubber membranes sealingly close the four windows by being attached to the logging sonde by conventional means, such as mechanical clips. The spaces between the four rubber membranes and the four piezoelectric members are filled by oil 116. O-rings 94 and 96 seal the contacting surfaces between pistons 83, 84 and logging sonde 20 to prevent leakage of oil 116. The sectorial spaces between the oil-filled spaces are filled by backing material 118 for damping out the reverberations of the vibrations of the four sectors.
To provide for passageway for electrical connections, piston 83 and piston rod 114 have holes 120, 121 through their centers respectively. The two holes communicate with each other. Piston rod 114 further has a passageway 122 which is perpendicular to its axis and which communicates with hole 121. Piston 83 further has four passages 123 each in communication at one end with the hole 120 and the other end of each leading to the outer cylindrical surface of one of the four members. Firing and recording control unit 62, comprising an electric pulse generator, is connected to the four members by two groups of wires: Group 124 comprising four wires 124a, 124b, 124c, and 124d; and Group 125 comprising wires 125a, 125b, 125c, and 125d. The Group 124 wires and the Group 125 wires are connected to the generator through a switch so that the pulses supplied to the outside surfaces of adjacent members may have the same or opposite polarities. Wires 124c and 124d are threaded through hole 120 and then through the passages 123 and are connected to the outer cylindrical surfaces of the members 104 and 108. Wires 124a and 124b are threaded through the hole 120 of piston 83 and hole 121 of piston rod 114 and are then connected through hole 122 and body 112 to the inner cylindrical surfaces of members 102 and 106 respectively. In a similar manner, wires 125a and 125b are threaded through hole 120, passages 123 and are connected to the outer cylindrical surfaces of members 102 and 106 respectively. Similarly, wires 125c and 125d are threaded through holes 120, 121 and 122 and are connected to the inner cylindrical surfaces of members 104 and 108 respectively. Thus, when the electrical pulse generator applies an electrical pulse across the two groups of wires, the pulse is applied across each pair of wires connected to one of the four members. If the Group 124 wires are connected to the positive terminal of the generator and the Group 125 wires to the negative terminal, the pulse causes the inner cylindrical surfaces of members 102 and 106 to be at a higher electrical potential than their outer cylindrical surfaces. If members 102 and 106 are polarized radially outward, it is well known that such electrical potentials will cause members 102 and 106 to contract radially initially. The pulses applied by the generator will cause the outer cylindrical surfaces of members 104 and 108 to be at a higher electrical potential than their inner cylindrical surfaces. Members 104 and 108 are polarized radially outward and such electrical potential will cause the two members to expand radially initially.
Connected in the above manner, therefore, substantially the same electrical pulse is applied by the generator substantially simultaneously to the four members, causing them to move substantially simultaneously: members 102 and 106 to contract and move inward initially and members 104 and 108 to expand and move outward initially. It is well known that after a piezoelectric material is caused to expand or contract initially by an electrical pulse, it will alternately expand and contract even though no electrical pulses are supplied after the initial triggering pulse. Thus, after the electrical pulses are applied to the four members which cause members 102 and 106 to contract and members 104 and 108 to expand, members 102 and 106 will then alternately expand and contract, and members 104 and 108 will alternately contract and expand. In their alternate expansions and contractions, the four members lose energy and their vibrations are eventually dampened out, but in the duration of their expansion and contraction, the four members generate four pressure wave trains. Since the four electrical pulses applied by the generator to the four members are substantially the same except for polarity, the four pressure wave trains have substantially the same wave form. The wave trains generated by members 102 and 106 are substantially in phase. The wave trains generated by members 104 and 108 are substantially in phase with each other but are substantially opposite in phase to the wave trains generated by members 102 and 106. Such pressure waves are transmitted through oil 116, the rubber membranes, then into the borehole fluid 24 and eventually into earth formation 26. The four pressure waves so generated will interfere and produce a quadrupole compressional wave in the earth formation 26. Such compressional wave propagates through the earth formation, is refracted back into the borehole fluid 24 and is detected at a distance from the logging source 10 as will be explained below.
The four piezoelectric members 102, 104, 106, and 108 may be readily made from piezoelectric crystals available commercially. Piezoelectric crystals supplied by the Vernitron Company of Bedford, Ohio have been satisfactory. One type of commercially available piezoelectric crystal is in the form of a hollow cylinder polarized radially outward. The inner and outer cylindrical surfaces of such crystals are each coated with a layer of conducting material, such as silver. Since the electrical pulse from the generator may be applied to adjacent members of the four members in opposite polarity, the inner cylindrical surfaces of adjacent members as well as their outer cylindrical surfaces must be electrically insulated. Such insulation may be achieved by cutting out four narrow longitudinal sections to yield the four sectors 102, 104, 106, and 108. Alternatively, instead of cutting out such narrow longitudinal sections, the conducting layer on both the inner and outer surfaces of such sections may be scraped off.
FIG. 4 is a simplified perspective view of the quadrupole P-wave logging device of FIG. 2, illustrating how the device may be used to log the P-wave velocity of the virgin formation. To detect the quadrupole P-wave generated by source 10, each detector of array 12 is preferably also a quadrupole detector of similar construction as source 10. For simplicity only detector D1 of array 12 is shown in FIG. 4. The four sectors of detector D1 are placed so that they have substantially the same axis as the four sectors of source 10 and that they have substantially the same lateral positions around the common axis as the sectors of source 10.
As shown in FIG. 4 the firing and recording control unit 62 supplies an electrical pulse across each of the four sectors through switch 64 such that the pulses supplied to any two adjacent sectors are opposite in polarity. By pulling switch 64, the polarities of the pulses supplied to the sectors may be changed so that the pulses supplied to all four sectors have the same polarity. That is, the outer cylindrical surfaces of the four sectors will have substantially the same electrical potential. Such potential will be different from the electrical potentials of the inner cylindrical surfaces of the four sectors. The inner cylindrical surfaces of the four sectors will also have substantially the same electrical potential. Where the pulses supplied to all four sectors have the same polarity, the four sectors are in the monopole mode. In this mode, all four sectors will radially expand and contract in substantially the same phase, and source 10 becomes a monopole source.
Each detector of array 12 may be connected to band pass filter 70 through switch 68 in substantially the same manner as the connection between firing and recording control unit 62 and source 10 such that if source 10 is operated in the quadrupole mode then each detector is also operated in a quadrupole mode, and if source 10 is operated in the monopole mode then each detector will also be operated in the monopole mode. With the arrangement illustrated in FIG. 4 the acoustic logging device of FIG. 2 may be used to log both the monopole P-wave arrival and the quadrupole P-wave arrival. As explained above, Pi, the P-wave traveling in the invaded zone may be comparable in amplitude to Pv, the P-wave traveling in the virgin formation. The monopole compressional wave log will indicate the arrival caused by compressional wave transmission through the invaded zone. This information may be helpful to identify noise in the quadrupole compressional wave log of Pv caused by Pi.
FIG. 5 is a cross-sectional view of another quadrupole P-wave logging source which may be used to log the P-wave velocities of formations away from the borehole. The source of FIG. 5 is similar in construction to the source of FIGS. 3 and 10 except that instead of four cylindrical sectors the source of FIG. 5 comprises four elongated piezoelectric composite plates 142, 144, 146 and 148 so spatially oriented within the logging sonde that the four plates form substantially the four rectangular sides of an elongated cube. Each of the four composite plates comprises two oppositely polarized piezoelectric plates bonded together. The four composite plates are attached to the logging sonde by two clamping plates (not shown in FIG. 5). Each of the two clamping plates has four slots into which the ends of the four composite plates are fitted snugly. The two clamping plates are then inserted into and attached to the sonde in such position that the elongated composite plates are substantially parallel to the logging sonde axis. The portion of each composite plate between the two ends will hereinbelow be called the "unclamped portion."
Substantially the same electrical pulse may be applied across the flat surfaces of each of the four composite plates substantially simultaneously. The pulses applied to any two adjacent composite plates may be opposite in polarity such that if the unclamped portion of one composite plate bends and move radially outward then the unclamped portions of the two adjacent composite plates will bend and move radially inward. The directions of the bending movements of the four composite plates are illustrated by hollow arrows in FIG. 5. The bending motions of the four composite plates will generate a quadrupole P-wave in the borehole liquid which is transmitted through the earth formation and detected as described above. To detect the quadrupole P-wave arrival in the borehole liquid the detectors in ray 12 are preferably the quadrupole type which may be of similar construction to the quadrupole sources illustrated in FIG. 3 or in FIG. 5. The quadrupole sources and detectors of the type illustrated in FIG. 5 may be operated as monopole sources and detectors in substantially the same manner as that described in FIG. 4.
The composite plates illustrated in FIG. 5 are available commercially. Composite plates supplied by the Vernitron Company of Bedford, Ohio have been found satisfactory.
FIG. 6 is a cross-sectional view of an octopole P-wave source which may be used to log the compressional wave velocity of the virgin formation. Six substantially similar sectors 162, 164, 166, 168, 170, 172 of a radially polarized piezoelectric hollow cylinder are so spatially arranged that they are substantially coaxial with and equidistant from the sonde axis. Substantially the same electrical pulse is applied across the cylindrical surfaces of each sector substantially simultaneously such that the pulses applied to any two adjacent sectors are opposite in polarity. This arrangement is illustrated in FIG. 6. With such an arrangement, adjacent sectors are caused to vibrate in opposite phases. If the six sectors are polarized radially outward then the directions of expansion and contraction of the six sectors as they begin to vibrate will be as illustrated by hollow arrows in FIG. 6. The vibrations of the six sectors will generate an octopole P-wave which is transmitted into the earth formation and detected as described above. To detect the octopole P-wave arrival the detectors of the ray 12 may be of similar construction to the octopole source illustrated in FIG. 6, or in FIG. 7, which will be described later. The octopole source illustrated in FIG. 6 may be attached to section 32 of sonde 22 in the same manner as the quadrupole source of FIG. 3. The section containing the octopole source of FIG. 6 may also be similar in construction to that of the section containing the quadrupole source of FIG. 3.
FIG. 7 is a cross-sectional view of still another octopole source which may be used to log the P-wave velocity of a virgin formation. The octopole source of FIG. 7 is similar to the quadrupole source of FIG. 5 except that six elongated composite plates are employed instead of four. The six elongated piezoelectric composite plates 182, 184, 186, 188, 190, 192 are so spatially arranged that they form substantially the parallelograms of a hexagonal prism. The six composite plates are attached to the logging sonde by clamping plates in a manner similar to that for the quadrupole source of FIG. 5. The unclamped portion of the six composite plates are vibrated by electrical pulses in a manner similar to that for the quadrupole source of FIG. 5 so that the unclamped portions of the adjacent plates will vibrate in substantially opposite phases. The directions of the bending movements of the six plates as they begin to vibrate are illustrated by hollow arrows in FIG. 7. The vibrations of the six plates will generate an octopole P-wave which penetrates the invaded zone to reach the virgin formation for logging the virgin formation.
The higher order multipole sources and detectors may be constructed in a manner similar to embodiments of the octopole P-wave source illustrated in FIGS. 6 and 7. Thus, the 16-pole source may be constructed by spatially arranging eight substantially identical sectors of a radially polarized piezoelectric hollow cylinder around a common axis. Substantially the same electrical pulse is applied to each sector such that adjacent sectors vibrate in substantially opposite phases. An alternative embodiment of the 16-pole source is constructed if the eight sectors are replaced by eight elongated piezoelectric composite plates arranged to form the eight parallelograms of an octagonal prism. Substantially the same electrical pulse is applied to each of the eight composite plates with such polarity that adjacent plates vibrate in substantially opposite phases. Other ways of constructing and vibrating the plates and sectors may be used so long as the plates and sectors are vibrated in the same manner. Other higher order multipole sources and detectors may be constructed in a similar manner. Preferably the detectors used to detect a higher order compressional wave arrivals will be of an order that matches the order of the source.
FIG. 8 is a cross-sectional view of a dipole P-wave source which may be used to log the compressional wave velocity of the virgin formation. Two substantially similar sectors 202 and 204 of a radially polarized piezoelectric hollow cylinder are so spatially arranged that they are substantially coaxial with and equidistant from the sonde axis. Substantially the same electrical pulse is applied across the cylindrical surfaces of each sector substantially simultaneously such that the pulses applied to the two sectors are opposite in polarity. This arrangement is illustrated in FIG. 8. With such an arrangement, the vibrations of the two sectors will generate a dipole P-wave which is transmitted to into the earth formation and detected as described above. The dipole source of FIG. 8 may be attached to section 32 in the same manner as the quadrupole source of FIG. 3. The section containing the dipole source of FIG. 8 may also be similar in construction to that of the section containing the quadrupole source of FIG. 3.
FIG. 9 is a cross-sectional view of still another dipole source which may be used to log the P-wave velocity of a virgin formation. The dipole source of FIG. 9 is similar to the quadrupole source of FIG. 5 except that a single elongated piezoelectric composite plate 222 is employed rather than four. Piezoelectric plate 222 may be attached to the logging sonde by clamping plates in a manner similar to that for the quadrupole source of FIG. 5. The unclamped portion of plate 222 is vibrated by electrical pulses in a manner similar to that for the quadrupole source of FIG. 5 to generate a dipole P-wave which is transmitted into the earth formation and detected as described above. The dipole source of FIG. 9 may be attached to section 32 in the same manner as the quadrupole source of FIG. 3. The section containing the dipole source of FIG. 9 may also be similar in construction to that of the section containing the quadrupole source of FIG. 3.
The number of composite plates or sectors in the embodiments of the octopole and the 16-pole source described above does not match the nomenclature of the octopole and 16-pole sources. Thus, a dipole (n=1) source comprises two times one or two plates or sectors. A quadrupole (n=2) source comprises two times two or four plates or sectors. An octopole (n=3), a 16-pole (n=4) and a 32-pole (n=5) source comprises six, eight, and ten plates or sectors respectively. Therefore, in general a 2 n -pole source will comprise 2n plates or sectors, n being an integer where n=1, 2, 3 and so on indefinitely.
The above description of method and construction used is merely illustrative thereof. Various changes in shapes, sizes, materials, or other details of the method and construction may be within the scope of the appended claims without departing from the spirit of the invention. | The inventive multipole acoustic wave logging method includes the steps of introducing a 2 n -pole acoustic wave into a virgin earth formation surrounding a borehole but separated from the borehole by an invaded zone, where n is an integer greater than zero, and detecting the refracted arrival of the 2 n -pole acoustic wave. The inventive apparatus includes means, separated from the borehole wall during operation, for generating a 2 n -pole acoustic wave that will propagate through the borehole fluid and thereafter into the virgin earth formation. If the 2 n -pole acoustic wave is a compressional wave, the compressional wave velocity of the virgin formation is determined from repeated measurements, at successively increased longitudinal spacings between the points of generation and detection of the 2 n -pole wave, of the time interval between detections of the refracted arrival of the 2 n -pole acoustic wave by the two detectors. If the 2 n -pole acoustic wave is a shear wave, the shear wave velocity of the virgin formation is similarly determined. The radius of the invaded zone may be determined from the compressional wave velocity in the virgin formation and in the invaded zone or from the shear wave velocity in the virgin formation and in the invaded zone. | 6 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates broadly to carbon dioxide sequestration. More particularly, this invention relates to methods for reducing leakage of sequestered carbon dioxide.
[0003] 2. State of the Art
[0004] Accumulating greenhouse gases have led to the advocation of separating and storing (sequestering) carbon dioxide from its sources. Carbon dioxide sequestration typically entails four distinct steps: the capture of the carbon dioxide from sources such as flue gas, transportation of the carbon dioxide to its ultimate storage site area, compression, and injection of the supercritical carbon dioxide downhole into the formation at a desired location (interval). Central to the success of the sequestration is the integrity of the downhole storage location; i.e., is the location sufficiently bounded by impermeable layers and seals. Because carbon dioxide is buoyant, particular attention is paid to the layer above the injected interval. For sequestration to be successful, any leak from the sequestration site must be inconsequential to inhabitants in the vicinity of the site. This is not exclusive to atmospheric leaks, but also to leaks into potable aquifers.
[0005] Generally, it is believed to be desirable to have more than one impermeable boundary between a selected injection (sequestration) zone and a potable aquifer. Thus, for example, assume with respect to FIG. 1 that a preferred injection zone is layer 0 . Layer 0 is defined as being between z=0 and z=z 0 where z is the vertical coordinate. Layer 0 is capped by a nearly impermeable layer 1 whose permeability is substantially smaller than layer 0 (preferably at least three orders of magnitude smaller) and is often in the range of ten or fewer microdarcies. Layer 1 is defined as being between z=z 0 and z=z 1 . Above layer 1 is a permeable stratum, layer 2 , which is defined as being between z=z 1 and z=z 2 . Layer 2 in turn is assumed to be overlain by another nearly impermeable shale or shaly sand. With this arrangement, it would be generally assumed that a potable aquifer above layer 2 would be sufficiently protected.
SUMMARY OF THE INVENTION
[0006] According to the invention, a dual completion and injection method is provided that reduces or eliminates upward leak rates of sequestered carbon dioxide. The dual completion and injection method involves the injection of a benign fluid such as brine or water into a permeable layer of the formation located above the sequestration layer and separated by a nearly impermeable layer (cap-rock). For purposes of this specification and the claims, hereinafter, the term “water” will be used in lieu of “brine” or “benign fluid”, as the brine and benign fluid will typically contain water. The water is preferably injected at the same time the supercritical carbon dioxide is injected. Simultaneous injection is preferably accomplished via a dual completion. The water is injected at a selected pressure.
[0007] According to one aspect of the invention, the wellbore sections communicating with the adjacent layers of the formation that are to receive the carbon dioxide and the water are provided with their own pressure sensor. The water is injected into its layer at a pressure at most equal to that of the sequestration layer corrected for the gravitational head of the respective fluids.
[0008] According to another aspect of the invention, the water is injected into its layer at a pressure between the pressure which is equal to that of the sequestration layer corrected for the gravitational head of the respective fluids minus an entry capillary pressure of carbon dioxide into the nearly impermeable cap-rock layer, and the pressure equal to the gravity head corrected value. In a preferred embodiment, the water is injected into its layer at a pressure which is equal to that of the sequestration layer corrected for the gravitational head of the respective fluids minus one-half the entry capillary pressure of carbon dioxide into the nearly impermeable cap-rock layer.
[0009] According to a further aspect of the invention, only a portion of the zone directly above the cap-rock layer is perforated for injection of water. When only a portion of the zone is perforated, preferably, the portion that is perforated is the portion directly adjacent the nearly impermeable cap-rock layer.
[0010] According to yet another aspect of the invention, the entire zone adjacent the cap-rock layer is perforated for fluid injection. If the fluid is of the same density as the formation fluid, then the entire zone would be uniformly flooded if the formation is homogeneous. Alternatively, perforation may be conducted along at least half of the zone such that the fluid spreads into the entire zone more readily than with a small length of perforation.
[0011] Objects and advantages of the invention will become apparent to those skilled in the art upon reference to the detailed description taken in conjunction with the provided figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a schematic diagram of a sample formation having multiple layers.
[0013] FIG. 2 is a schematic showing a dual-completion well for sequestration of carbon dioxide.
[0014] FIG. 3A is a three-dimensional plot generated from a model assuming no injection of water in a permeable zone above the cap-rock of the sequestration zone, and indicating limited migration of carbon dioxide.
[0015] FIG. 3B is a graph showing injection and leakage rates of carbon dioxide for the model of FIG. 3A .
[0016] FIG. 4A is a three-dimensional plot generated from a model assuming injection of water in a small portion of a permeable zone above the cap-rock of the sequestration zone, and indicating more limited migration of carbon dioxide.
[0017] FIG. 4B is a graph showing injection rates of carbon dioxide and water, and the leakage rate of carbon dioxide for the model of FIG. 4A .
[0018] FIG. 5A is a three-dimensional plot generated from a model assuming injection of water in the entire permeable zone above the cap-rock of the sequestration zone, and indicating very little migration of carbon dioxide.
[0019] FIG. 5B is a graph showing injection rates of carbon dioxide and water, and leakage rate of carbon dioxide for the model of FIG. 5A .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] Turning now to FIG. 1 , a formation 10 traversed by a cased wellbore 20 is posited. Formation 10 includes many layers or zones although only four layers are shown in FIG. 1 . As previously mentioned, layer 0 is defined as being between z=0 and z=z 0 where z is the vertical coordinate. Layer 0 is capped by nearly impermeable layer 1 which is defined as being between z=z 0 and z=z 1 . Above layer 1 is a permeable stratum, layer 2 , which is defined as being between z=z 1 and z=z 2 . Layer 2 in turn is assumed to be overlain by another nearly impermeable shale or shaly sand layer 3 . For purposes of modeling with a reservoir simulator such as ECLIPSE (a trademark of Schlumberger), GEM (a trademark of Computer Modelling Group), or TOUGH2 (Lawrence Berkeley National Laboratory), layer 0 is assumed to be 30 meters thick, layer 1 is assumed to be 10 meters thick, and layer 2 is assumed to be 30 meters thick. The thickness of layer 3 is irrelevant for purposes of analysis. Layer 1 is assumed to have a porosity of 0.05 (dimensionless) and a permeability of 0.01 mD (which is higher than what is typically expected downhole for impermeable zones). Layers 0 and 2 are assumed to have a porosity of 0.2 and a permeability of 100 mD. The radius of wellbore 20 is assigned to be 0.1 m, and the outer radius of the formation 10 is set at 2000 m.
[0021] As seen with reference to FIG. 2 , the wellbore 20 is assumed to have a dual completion installed. Thus, coaxial tubes 30 a, 30 b are provided with respective packers 40 a, 40 b, 40 c such that tube 30 a is in fluid communication with layer 2 of the formation via casing perforations 50 a, and tube 30 b is in communication with layer 0 of the formation via casing perforations 50 b. Pressure sensors 60 a, 60 b are provided in conjunction with tubes 30 a and 30 b with the assumption that the measured pressure is at the top of the respective perforations for the purpose of reference datum. Any other datum is equally acceptable, as long as the hydrostatic correction is applied properly. Supercritical carbon dioxide is injected by suitable means, e.g., pressure controlled pump 70 b into layer 0 via tube 30 b (displacing brine in that layer). Benign fluid, such as compatible water (e.g., brine) (hereinafter referred to as “water”) is injected by suitable means, e.g., pressure controlled pump 70 a into layer 2 via tube 30 a at a pressure equal to that of the pressure of layer 0 corrected for the gravitational head of the respective fluids, minus a fraction of the entry capillary pressure of carbon dioxide into the nearly impermeable cap-rock layer. The pressure of pumps 70 a, 70 b is preferably controlled by a controller 80 which receives information from pressure sensors 60 a, 60 b and which causes the pumps 70 a, 70 b to pump the supercritical carbon dioxide and water into layers 0 and 2 of the formation as described more completely hereinafter in order to properly sequester the carbon dioxide in layer 0 . More particularly, if z=z m0 is the pressure measurement point for layer 0 , and z=z m2 is the pressure measurement point for layer 2 , then according to one aspect of the invention, the water injection pressure p wi (measured by sensor 60 a ) is kept at at least
[0000] p wi =p gi −ρ g g( z 0 −z m0 )+ρ w g( z 0 −z m2 )−p b (1)
[0000] where p gi is the carbon dioxide injection pressure (measured by sensor 60 b ), g is the acceleration due to gravity, and ρ g and ρ w are the densities of the supercritical carbon dioxide and water respectively. It is noted that the second and third terms of the right hand portion of equation (1) is the correction due to the gravitational head of the respective fluids and the fourth term is the entry capillary pressure into the caprock.
[0022] According to another aspect of the invention, the water injection pressure may be increased to levels higher than the level of equation (1). More particularly, in one embodiment, the water injection pressure is increased to the gravity head corrected injection pressure of carbon dioxide i.e., the first three right hand terms of equation (1). In another embodiment, the water injection pressure is increased by a value equal to half the entry capillary pressure of carbon dioxide into layer 1 from equation (1). By increasing the pressure in layer 2 by this amount, carbon dioxide from layer 0 will not penetrate layer 1 , as the higher pressure in water provides a safety margin. In a controlled water injection process, the increased value from equation (1) may range from one-quarter to three quarters the entry capillary pressure of the cap-rock.
[0023] By keeping the water pressure at or above the pressure dictated by equation (1), vertical migration of carbon dioxide is suppressed other than purely by diffusion. Diffusion of the carbon dioxide is not of particular concern, however, because the diffusion time scale T D through layer 1 will typically be thousands of years. More particularly, if the characteristic diffusion constant is D, then the diffusion time T D is
[0000]
T
D
=
φ
1
F
1
h
1
2
D
(
2
)
[0000] where F 1 is the formation factor for layer 1 , h 1 is the layer thickness, and φ 1 is the porosity. For nominal parameter values (e.g., φ 1 =0.05, F 1 =(1/φ 1 ) 2 , D=10 −9 m 2 s −1 , h 1 =10 m), the diffusion time T D will be about 60,000 years and is of little relevance to short and medium term leak mitigation.
[0024] In a simulation of two-phase flow, the system of FIG. 1 was utilized. It is assumed that at radial boundary of the formation (e.g., 2000 m), quiescent reservoir pressure gradient is maintained. For capillary pressure, drainage and imbibition capillary pressures according to R. H. Brooks and A. T. Corey, “Properties of Porous Media Affecting Fluid Flow”, J. Irrig. Drainage Div., 92 (IR2):61-88 (1966), and T. S. Ramakrishnan and D. Wilkinson, “Formation Producibility and Fractional Flow curves from Radial Resistivity Variation Caused by Drilling Fluid Invasion”, Phys. Fluids, 9(4):833-844 (1997) are used, with the entry capillary pressure p b for the layer of interest defined by
[0000]
p
b
=
C
γ
φ
k
(
3
)
[0000] where γ is the interfacial tension between carbon dioxide and water, and C is typically a fraction less than unity (e.g., 0.2). Thus, for layer 1 , the porosity (φ 1 ) and permeability (k 1 ) of layer 1 are utilized in equation (3). As previously mentioned, equation (3) may be utilized for purposes of determining a desired water injection pressure into layer 2 . Thus, in accord with one aspect of the invention, the water injection pressure is chosen to be a value equal to the value dictated by equation (1) where p b is given by equation (3). Most preferably, the water injection pressure is chosen to be the value dictated by equation (1) plus one-half the value dictated by equation (3). According to another aspect of the invention, the water injection pressure may be chosen to be
[0000] p wi =p gi −ρ g g( z 0 −z m0 )+ρ w g( z 0 −z m2 )−αp b (4)
[0000] where α is a number in the range 0 to 1. Preferably α is between 0.25 and 0.75.
[0025] For the purpose of illustrating the feasibility of the invention through reservoir simulation, in terms of fluids, brine is considered displaced through nonwetting supercritical carbon dioxide injection. Injection of carbon dioxide is confined to layer 0 . The density of the supercritical carbon dioxide is set at 700 kg/m 3 at 15 MPa, with a compressibility and viscosity of 3×10 −8 Pa −1 and 6×10 −5 Pa-s respectively. The resident brine and the injected water are assigned a density of 1100 kg/m 3 and a viscosity of 6×10 −4 Pa-s. Compressibility effect for the aqueous phase is negligible and is therefore ignored. During injection of carbon dioxide and subsequent counter imbibition, residual saturations (of brine and carbon dioxide respectively) are left behind. For residual water saturation, i.e., the maximum fraction of the pore volume occupied by the trapped wetting phase, a value of 0.075 is assigned. For the maximum residual carbon dioxide saturation, a value of 0.3 is used. Before commencement of injection, the pressure at the top of layer 2 is 13 MPa; i.e., this is the initial reservoir pressure at the top of layers of interest in the illustration. Carbon dioxide injection is assumed to occur through the bottom ten meters of the thirty meter layer 0 , at a fixed pressure.
[0026] With the formation described above with reference to FIG. 1 , and with the formation simulation values as described above, simulations were run for three different scenarios. In a first scenario (Example 0), it was assumed that carbon dioxide was injected into layer 0 without injection of water into layer 2 . In a second scenario (Example 1), it was assumed that carbon dioxide was injected into layer 0 and water was simultaneously injected into the bottom two meters of layer 2 . In a third scenario (Example 2), it was assumed that carbon dioxide was injected into layer 0 and water was simultaneously injected along the entire length of layer 2 .
[0027] More particularly, Example 0 is considered as a baseline for the purpose of characterizing carbon dioxide leakage in the absence of the method of the invention. The model assumes that carbon dioxide injection is carried out at a fixed layer 0 top-perforation pressure of 17 MPa for 730 days. Over the 730 days, 1.137 Tg (1 Tg=10 6 metric tons) of carbon dioxide is injected into the formation. FIG. 3A is a plot generated by the model which shows the results of the carbon dioxide injection. As can be seen from FIG. 3A (where depth 0 correlates to the beginning or bottom of layer 0 ), wherever the water saturation S w is less than one, carbon dioxide is present. Thus, in layer 0 (0 to 30 meters), the carbon dioxide has migrated such that brine has been at least partially displaced radially over 800 meters. In layer 1 (from 30 to 40 meters), the carbon dioxide has migrated about 400 meters (between about 30 and 32 meters). Although impossible to see in FIG. 3A , the model reveals that carbon dioxide is about to break through into layer 2 in the proximity of the wellbore.
[0028] FIG. 3B shows the injection rate for carbon dioxide over the 730 days and the carbon dioxide leakage (into layers 1 and 2 ). While the cumulative leakage amounted to 12.9 Gg, which is only approximately 1.14% of the cumulative injected carbon dioxide, it represents a concern.
[0029] Example 1 considers the simultaneous injection of water and carbon dioxide. The model assumes that carbon dioxide injection is carried out at a fixed layer 2 top-perforation pressure of 17 MPa for 730 days. Over the 730 days, 1.133 Tg of carbon dioxide is injected (the total being marginally less than Example 1 because of the effects of water injection into layer 2 ). The model also assumes that the wellbore is perforated at the bottom two meters of layer 2 , and the pressure at the top of this perforated interval was specified to be 16.53 MPa (which was above the 15.89 MPa calculated by equation (4), for α=1, and slightly above the 16.32 MPa obtained from equation (4) with α=½, but below 16.77 MPa with α=0; the value used was α≈¼). FIG. 4A is a plot generated by the model which shows the results of the carbon dioxide injection. As can be seen from FIG. 4A , wherever the water saturation S w is less than one, carbon dioxide is present. Thus, in layer 0 (0 to 30 meters), the carbon dioxide has migrated such that brine has been at least partially displaced radially over 800 meters. In layer 1 (from 30 to 40 meters), the carbon dioxide has migrated radially about 400 meters (between about 30 and 32 meters). The model reveals that for Example 1, the carbon dioxide has not broken through into layer 2 at all.
[0030] FIG. 4B shows the injection rates for carbon dioxide and water for the 730 days and the carbon dioxide leakage (into layer 1 ) over that period of time. The cumulative leakage amounted to 10.1 Gg, which is approximately 0.9% of the cumulative injected carbon dioxide. This represents an improvement of approximately 25% relative to Example 0 and is therefore useful. However, the 0.9% leakage rate is still not ideal.
[0031] Example 2 considers the simultaneous injection of water and carbon dioxide where water is injected over the entire layer 2 interval. The model assumes that carbon dioxide injection is carried out at a fixed top-perforation pressure of 17 MPa for 730 days. Over the 730 days, 1.115 Tg of carbon dioxide is injected. The model also assumes that the wellbore is perforated along all thirty meters of layer 2 , and the pressure at the top of this perforated interval was specified to be 16.23 MPa (which is above the 15.59 MPa for α=1 calculated by equation (4), and even above the 16.01 MPa obtained obtained from equation (4) with α=½, but below the 16.44 MPa obtained from equation (4) with α=0; the value used was α≈¼). FIG. 5A is a plot generated by the model which shows the results of the carbon dioxide injection. As can be seen from FIG. 5A , wherever the water saturation S w is less than one, carbon dioxide is present. Thus, in layer 0 (0 to 30 meters), the carbon dioxide has migrated such that brine has been at least partially displaced radially over 800 meters. However, importantly, the model concludes that the migration of carbon dioxide into layer 1 is negligible.
[0032] FIG. 5B shows the injection rates for carbon dioxide and water for the 730 days and the negligible leakage of carbon dioxide into layer 1 over that period of time. Thus, the arrangement of Example 2 is superior in sequestering carbon dioxide. A side-by-side comparison of the baseline of Example 0, and Examples 1 and 2 is seen in the following table.
[0000]
Leaked CO2
Inj. Water
Example #
Cum. Inj. CO2 (Tg)
(Tg)
%
(Tg)
%
0
1.1367
0.01293
1.138
—
—
1
1.1329
0.01014
0.895
0.1168
10.31
2
1.1153
0.00007
0.006
0.6561
58.82
[0033] It is noted that while the water was injected over a length of thirty meters in Example 2 relative to the two meters in Example 1, the injection rate of the water, and hence the total amount of water injected is approximately six times the injection rate and total injection amount of Example 1 (compare FIG. 5B to FIG. 4B ) less than the fifteen times one would expect based on length of perforations. This is because water injected into the bottom 2 m spreads over the entire width of layer 2 as it moves radially into the formation.
[0034] According to another aspect of the invention, it is possible to simulate different perforation lengths in the water zone less than the maximum length, and compare the total injected water and the total carbon dioxide leakage. Then, it should be possible to find a minimum perforation length where the total carbon dioxide leakage is acceptable. That perforation length can be considered optimal as using the least water which will lead to the said acceptable carbon dioxide leakage.
[0035] Based on all of the foregoing, one method according to the invention includes: a) choosing a sequestration site for the purpose of carbon dioxide sequestration by finding a permeable layer (e.g., >1 mD) which is overlain by a nearly impermeable layer (e.g., <0.01 mD), which in turn is overlain by a permeable layer; b) completing the well with dual completions and with perforations for the purpose of injecting carbon dioxide into the lower permeable layer and injecting water (brine) or a substantially inert (benign) fluid into the overlaying permeable layer; and c) injecting carbon dioxide and water into their respective layers simultaneously, with the nearly impermeable layer there-between, where the water is injected into its layer at a pressure of at least
[0000] p wi =p gi −ρ g g( z 0 −z m0 )+ρ w g( z 0 −z m2 )−p b
[0000] and at most
[0000] p wi =p gi −ρ g g( z 0 −z m0 )+ρ w g( z 0 −z m2 ).
[0036] In order to choose the sequestration site, logs of the formation should be reviewed. The logs can be sonic logs, acoustic logs, nuclear logs, magnetic resonance logs, electromagnetic logs, formation testing logs, or any other log or combination of logs which provides an indication of the depth and location of the layers of the formation and an indication of the permeability of the layers.
[0037] Dual completion of the wellbore may be accomplished according to any desired technique. Likewise, perforation of the wellbore may be accomplished according to any desired technique.
[0038] According to one aspect of the invention, the water is injected at a pressure equal or greater than
[0000]
p
wi
=
p
gi
-
ρ
g
g
(
z
0
-
z
m
0
)
+
ρ
w
g
(
z
0
-
z
m
2
)
-
C
γ
φ
1
k
1
[0000] and preferably less than p wi =p gi −ρ g g(z 0 −z m0 )+ρ w g(z 0 −z m2 ), where C is between 0.1 and 0.3 and preferably 0.2.
[0039] According to another aspect of the invention, the water is injected at a pressure in the range of
[0000]
p
wi
=
(
p
gi
-
ρ
g
g
(
z
0
-
z
m
0
)
+
ρ
w
g
(
z
0
-
z
m
2
)
)
-
(
.5
±
.25
)
C
γ
φ
1
k
1
,
[0000] where C is between 0.1 and 0.3 and preferably 0.2.
[0040] According to a further aspect of the invention, the water is injected into the overlaying permeable layer along a length nearest the impermeable layer.
[0041] According to a further aspect of the invention, using information regarding the formation layers, simulations are conducted to find a desired length of the overlaying permeable layer to perforate. The simulations should provide indications of carbon dioxide leakage, if any, from the first permeable layer as a function of the length of the perforation. Preferably, the simulations also provide the amount of water injected into the overlaying permeable layer.
[0042] According to yet another aspect of the invention, the pressure in both injection intervals is measured downhole. According to another aspect of the invention, a control system (not shown) may be provided to maintain the injection pressures in the respective completions.
[0043] According to even another aspect of the invention, carbon dioxide is sequestered in a formation where the first permeable layer is relatively large (e.g., a depth of more than 30 m), and the permeable layer (layer 2 ) overlaying the non-permeable layer is relatively thin (e.g., a few meters thick) and has a permeability substantially less than the first permeable layer. In this manner, the amount of water which should be injected into layer 2 is reduced as the volume of water expected to be injected scales with the product of the permeability and thickness of layer 2 .
[0044] There have been described and illustrated herein several embodiments of a system and a method of sequestering carbon dioxide in a formation. While particular embodiments of the invention have been described, it is not intended that the invention be limited thereto, as it is intended that the invention be as broad in scope as the art will allow and that the specification be read likewise. Thus, while particular simulation tools have been disclosed for the purpose of determining an optimal perforation length with respect to preventing carbon dioxide leakage while minimizing water usage, it will be appreciated that other simulation tools could be used as well. It will therefore be appreciated by those skilled in the art that yet other modifications could be made to the provided invention without deviating from its spirit and scope as claimed. | Carbon dioxide is sequestered in a formation using a dual completion and injection method that reduces or eliminates upward leak rates of the sequestered carbon dioxide. The dual completion and injection method involves the injection of a benign fluid such as brine (water) into a permeable layer of the formation located above the sequestration layer and which is separated form the sequestration layer by a nearly impermeable layer. The water is preferably injected at the same time the carbon dioxide is injected. | 4 |
BACKGROUND OF THE INVENTION
The present invention relates to a system for controlling the ignition timing of an internal combustion engine such as an automotive engine.
A learning control system for correcting the ignition timing has been proposed. The control system is adapted to advance the ignition timing so as to produce a maximum torque as long as the level of engine knocking does not exceed a tolerable level. The ignition timing stored in a RAM is corrected by a small correcting quantity (quantity of correction) and converges to a desired value little by little. The correcting quantity for the ignition timing at every updating operation is gradually reduced as the ignition timing approaches the desired value.
In order to reduce the correcting quantity, it is necessary to determining that the corrected ignition timing approaches the desired timing. If the decision is not properly made, it takes a long time for the ignition timing to converge to the desired timing.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a control system whereby the ignition timing can quickly converge to a desired ignition timing.
In the system of the invention, the number of inversions of correcting direction, such as from advancing to retarding, is counted up. The quantity of correction at a time is gradually reduced as the number increases, so that the ignition timing quickly/converges to a desired timing.
According to the present invention, there is provided a system for controlling the ignition timing of an internal combustion engine having a microprocessor and an ignition timing control device comprising, sensing means for sensing operating conditions of the engine and for producing an engine operating condition signal, a knock sensor for sensing engine knock and for producing a knock signal.
The system further comprises first means responsive to the engine operating condition signal and knock signal for producing an ignition timing correcting signal representing an ignition timing correcting quantity at a time for deciding the ignition timing, second means for counting up the number of inversions of the correcting direction dependent on the ignition timing correction signal, and third means for reducing the ignition timing correcting quantity as the number increases.
The other objects and features of this invention will become understood from the following description with reference to the accompanying drawings.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a block diagram showing a control system according to the present invention;
FIG. 2 is a block diagram showing a main part of the control system;
FIG. 3a and 3b show tables storing a plurality of ignition timings;
FIG. 4 shows a range of a coefficient K;
FIGS. 5, 6, 7a and 7b are flowcharts showing the operation of the system; and
FIGS. 8a and 8b show a retard coefficient table and an advance determining period table, respectively.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, an intake air pressure (or quantity) sensor 1, an engine speed sensor 4 such as a crankangle sensor, and a knock sensor 7 are provided to detect engine operating conditions. The output of the sensor 1 is applied to an A/D converter 3 through a buffer 2, and the output of the sensor 4 is applied to an interrupt processing circuit 6 through a buffer 5. The output of the knock sensor 7 is applied to a comparator 12 through a filter 8 and amplifier 9, and, on the other hand, to the comparator 12 through a rectifier 10 and amplifier 11. The comparator 12 compares both inputs and produces an output signal when engine knocking having a higher level than a predetermined value occcurs. Outputs of the A/D converter 3, circuit 6 and comparator 12 are applied to a microprocessor 18 through an input port 13.
The microprocessor 18 comprises a CPU 15, RAM 16, ROM 17 and output port 14. The output of the microprocessor 18 is applied to an ignition timing control device 21 through a driver 19 so as to control the ignition timing in accordance with the engine operating conditions sensed by the sensors 1, 4 and 7.
FIG. 5 summarizes the operation of the control system. The operation is divided into a rough correction and a fine correction. Step 30 determines whether a rough correction has been executed (whether a rough correction completion flag RCMP is set). In accordance with the decision, the rough correction or fine correction is executed in a rough correction subroutine 31 or a fine correction subroutine 32. At a step 33, a real ignition timing SRK real is calculated.
The rough correction is an operation for obtaining a basic ignition timing SPK bs which is calculated in a basic ignition timing setting circuit 71 shown in FIG. 2. FIG. 6 shows the operation of the rough correction. At a step 37, engine speed and intake air pressure are calculated based on the output signals of the sensors 1 and 4. Thereafter, at a step 38, a first maximum ignition timing MAPSTD and a second maximum ignition timing MBT are read from tables 38a and 38b (FIGS. 3a, 3b)in the ROM 17, in accordance with the engine speed and intake air pressure. The first maximum ignition timing is maximum timing for producing maximum torque with low-octane gasoline without the occurrence of knocking and the second maximum ignition timing is maximum timing for producing maximum torque with high-octane gasoline without the occurrence of knocking.
In the system, a coefficient K for correcting the ignition timing is provided. The value of the coefficient K is preliminarily set to a value between zero and 1 as shown in FIG. 4.
The coefficient K is stored in the RAM 16 and updated in accordance with engine operating conditions so that the ignition timing roughly converges to a desired ignition timing. The updating is performed under a predetermined condition and the condition is determined at a step 39. When the difference between the first and second maximum ignition timings read from the tables 38a and 38b is larger than a predetermined degree, for example 5°, the updating is performed. Namely, the program proceeds to a step 40, where it is determined whether a knocking has occurred during the program. When the occurrence of knocking is determined, the program proceeds to a step 41, and if not, proceeds to a step 42. At step 41, the coefficient K is decremented by a correcting quantity ΔK(ΔK=K/2), and the remainder K - ΔK is stored in the RAM 16 as a new coefficient for the next updating. Accordingly, the correcting quantity ΔK at the next updating is (K - αK)/2. Namely, the correcting quantity is a half of the coefficient K at updating. More particularly, if the initial coefficient is 1/2, the correcting quantity is 1/4, and if it is 0 or 1, the correcting quantity is 1/2 as seen from FIG. 4.
At the step 42, it is determined whether the engine has operated without knocking for a predetermined period. When knocking does not occur for the period, the coefficient K is incremented by the correcting quantity ΔK at a step 43.
After the updating of the coefficient K at step 41 or 43, it is determined whether the rough correction is completed at a step 44. As will be understood from the above description, the correcting quantity ΔK decreases as the number of the correction increases. In the system, when the correcting quantity reaches a predetermined small value, the rough correction is completed. Accordingly, if the quantity ΔK reaches the predetermined value, a rough correction completion flag RCMP is set at a step 45, or if not, the flag is reset at a step 46. On the other hand, the total correcting quantity SPK prt and the number of correction NUM of ignition timing are stored in an ignition timing correcting quantity table 73 and a table 74 (FIG. 2) for the number of correction. At a step 47, a basic ignition timing SPK bs is calculated by the following formula
SPK.sub.bs =MAPSTD+K×ΔMAPMBT --- (1)
where ΔMAPMBT=MBT - MAPSTD
The basic ignition timing is applied to an engine 72 (FIG. 2) to operate the engine at the ignition timing. The coefficient K is stored in the RAM 16. If the rough correction is not completed, the coefficient K is updated at the next program so that the ignition timing roughly converges to a desired ignition timing as described above. It will be understood that if the initial coefficient K is O, the basic ignition timing SPK bs calculated by the formula (1) is the maximum ignition timing MAPSTD at the first program. The basic ignition timing SPK bs obtained by the rough correction is further corrected by the fine correcting operation as described hereinafter.
Referring to FIGS. 7a and 7b, at a step 52, it is determined whether the engine operation is in a range which is proper to correct the basic ignition timing SPK bs . If it is in the range, the correcting quantity SPK prt and the number of the inversions of correcting direction NUM are read from tables 73 and 74 at a step 53. Then, at a step 54, a retard coefficient LN for retarding quantity RET is looked up from a retard coefficient table 75 (FIG. 2) of FIG. 8a in accordance with the number of the inversions of the correcting direction NUM, and an advance determining period ADJ is looked up from an advance determining period table 76 (FIG. 2) of FIG. 8b in accordance with the number of the inversions of the correcting direction NUM. Thereafter, the program proceeds to a step 55, where it is decided whether knocking has occurred during the program. When the occurrence of knocking is determined, the program proceeds to a step 56, and if not, it proceeds to a step 59. At step 56, the intensity of the knocking and the interval of the knocks are calculated at a calculating circuit 78 (FIG. 2), and then, retarding quantity KNK is looked up from a retarding quantity table 79 in accordance with the intensity and the interval of the knocks At a step 57, a real retarding quantity RET real is calculated by multiplying the retarding quantity KNK and retard coefficient LN together (RET real =KNK×LN). Thereafter, the program proceeds to a step 58, where the correcting quantity SPK prt stored in the table 73 is subtracted with the real retarding quantity RET real to obtain a new correcting quantity SPK prtr which is stored in the table 73.
On the other hand, at the step 59, it is decided whether knocking occurs in the advance determining period ADJ, which is performed at a comparator 80 in FIG. 2. When knocking does not occur in the period, the program proceeds to a step 60, where an advancing quantity ADV of a constant small value is added to the correcting quantity SPK prt to obtain a new correcting quantity SPK prta which is performed in an advancing quantity setting circuit 81 in FIG. 2 and stored in the table 73. Thereafter, at a step 61, it is determined whether the new correcting quantity SPK prta is larger than a limit value which is obtained by subtracting the basic ignition timing SPK bs from the maximum ignition timing MBT (MBT-SPK bs ). When the new correcting quantity SPK prta is smaller than the limit value, the new correcting quantity is stored in the table 73 at a step 63. If it is larger than the limit value, the value of MBT-SPK bs is used as a new correcting quantity (at a step 63) and stored in the table 73. The real ignition timing SPK real is calculated by the following formula. ##EQU1## After steps 58 and 63, it is determined whether the correcting direction in the program is the inverse of the correcting direction in the last program at steps 64 and 65. Namely, at step 64, it is determined whether the ignition timing is advanced in the last program, and, at step 65, it is determined whether the timing is retarded. If the inversion of direction is made, the program proceeds to a step 67 or 68, where a signal is applied to a counter to count the number of inversions of correcting direction and the number is stored in a table. When the corrected ignition timing approaches the desired timing, the direction of correction tends to reverse. In other words the fact of the number becoming large means that the corrected timing approaches the desired timing. Accordingly, the retard coefficient LN shown in FIG. 8a decreases and the advance determining period ADJ of FIG. 8b increases with an increase of the number of the inversions NUM. Thus, in accordance with the present invention, the progress of correction can be exactly detected and it is possible to cause the ignition timing to quickly converge to a desired timing.
While the presently referred embodiment of the present invention has been shown and described, it is to be understood that this disclosure is for the purpose of illustration and that various changes and modifications may be made without departing from the scope of the invention as set forth in the appended claims. | A system for quickly converging the ignition timing to a desired timing. The number of inversions of correcting direction, such as from advancing to retarding, is counted up. The quantity of correction at a time is gradually reduced as the number increases. | 5 |
STATEMENT REGARDING FEDERALLY-SPONSORED RESEARCH OR DEVELOPMENT
[0001] This invention was made with Government support under Contract DE-AC0676RLO1830 awarded by the U.S. Department of Energy. The Government has certain rights in the invention
TECHNICAL FIELD
[0002] This invention relates to spinel-structured metal oxides epitaxially grown on substrates by molecular beam epitaxy. More particularly but not exclusively, this invention relates to a method of making a thin film of an inverse spinel-structured binary ferrite, such as CoFe 2 O 4 , on a substrate for magnetic media applications.
BACKGROUND INFORMATION
[0003] Growth of high-quality spinel-structured metal oxide films on substrates is important in a variety of chemical, electronic, and magnetic applications. Many of the technological advances in this field have been in the techniques to grow high quality Fe 3 O 4 (magnetite) thin films utilizing physical vapor deposition techniques such as plasma laser deposition (PLD) and molecular beam epitaxy (MBE), for example as disclosed in Lind et al. Phys. Rev. B 45 (4) 1838, Jan. 15 1992 and Chambers, S. A. Surf. Sci. Rep. 39 (2000) 105. Less progress has been achieved, however, in producing high-quality spinel-structured metal oxide films having more than one metal constituent, such as the binary oxides of CoFe 2 O 4 (Co ferrite), NiFe 2 O 4 (Ni ferrite), and CoCr 2 O 4 (Co chromite), and the ternary oxide of (Mn,Zn)Fe 2 O 4 . Co ferrite is of particular interest for a variety of next-generation magnetic read/write technologies because it exhibits magnetic properties that are significantly enhanced compared to those of other magnetic oxides.
[0004] Although the bulk properties of Co ferrite have been known for decades, thin film synthesis and characterization efforts have been limited. Suzuki et al. (1) (Appl. Phys. Lett. 68 (5) 714, Jan. 29 1996), Suzuki et al. (2) (J. of Magnetism and Magnetic Materials 191 (1999) 1), and Hu et al. (Phys. Rev. B 62 (2) R779, Jul. 1 2000) disclose PLD techniques to grow Co ferrite on a variety of substrates, including MgO, SrTiO 3 and MgAl 2 O 4 . Hu et al. asserts that epitaxial Co ferrite of high magnetic and structural quality cannot be grown without the use of a complex crystal symmetry and lattice parameter matching scheme involving the use of buffer layer, such as CoCr 2 O 4 , on substrates such as MgAl 2 O 4 . Substrates of different symmetry, such as MgO, are thought to result in the nucleation and growth of Co ferrite that has high concentrations of a particular structural defect called an antiphase boundary, and that the presence of these defects compromises the magnetic properties. Even with these more complex substrate/buffer layer combinations, a post-growth anneal is required to obtain the desired structural and magnetic properties when PLD is used as the growth method. Furthermore, PLD-grown film surfaces show considerable roughness (see FIG. 1 of Suzuki et al. (2)) which precludes the formation of laminar film structures and superlattices.
[0005] Further improvement in current methods, however, is necessary if magnetic spinels are to be broadly useful in magnetic media applications. Desirable properties include hysteretic magnetization loops and atomically flat films grown on simple substrates, such as MgO. PLD has not produced Co ferrite with these desirable properties. Accordingly, there is a need for an improved process for epitaxially growing a spinel-structured metal oxide on a substrate.
BRIEF SUMMARY OF THE INVENTION
[0006] An embodiment of the present invention encompasses a method of making a spinel-structured metal oxide on a substrate by molecular beam epitaxy, the metal oxide comprising oxygen atoms, first metal atoms, and at least one other metal atoms, wherein the metal atoms substantially occupy thermodynamically stable lattice positions of the metal oxide during the growth of the metal oxide on the substrate.
[0007] Another embodiment of the present invention encompasses a method of making a spinel-structured metal oxide on a substrate by oxygen plasma assisted molecular beam epitaxy. This embodiment comprises the step of supplying activated oxygen, a first metal atom flux, and at least one other metal atom flux to the surface of the substrate, wherein the metal atom fluxes are individually controlled at the substrate so as to grow the spinel-structured metal oxide on the substrate and the metal oxide is substantially in a thermodynamically stable state during the growth of the metal oxide.
[0008] A particular embodiment of the present invention encompasses a method of making a spinel-structured binary ferrite on a substrate, wherein the binary ferrite is substantially in a thermodynamically stable state during the growth of the binary ferrite.
[0009] A more particular embodiment of the present invention encompasses a method of growing Co ferrite on a substrate, wherein the Co ferrite is substantially in a thermodynamically stable state during the growth of the Co ferrite.
[0010] It is an object of the present invention to provide a spinel-structured metal oxide with improved properties resulting from the metal oxide being substantially in a thermodynamically stable state without having undergone a post-growth annealing treatment.
[0011] It is a further object of the present invention to provide a spinel-structured metal oxide film having at least two metal constituents and an atomically flat surface.
[0012] It is a further object of the present invention to make a metal oxide with an inverse spinel structure, such as Co ferrite, without the need of a post-growth annealing treatment.
[0013] It is a further object of the present invention to provide a high quality Co ferrite film that can be used, for example, in magnetic media applications.
[0014] The subject matter of the present invention is particularly pointed out and distinctly claimed in the concluding portion of this specification. However, both the organization and method of operation, together with further advantages and objects thereof, may best be understood by reference to the following description taken in connection with accompanying drawings wherein like reference characters refer to like elements.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] [0015]FIG. 1 schematically illustrates an example of a molecular beam epitaxy system that can be used in producing the spinel-structured metal oxide of the present invention. This particular system comprises an electron cyclotron resonance oxygen plasma generator as the source of activated oxygen and an atomic absorption spectroscopy detection system (not shown) for determining, monitoring, and controlling metal evaporation and deposition rates.
[0016] [0016]FIG. 2 a illustrates an atomic absorption/metal evaporation rate calibration curve for Co, showing the evaporation rates required to synthesize Co ferrite that is stoichiometric to within 10%. The evaporation rates were determined by a quartz crystal oscillator at the substrate location.
[0017] [0017]FIG. 2 b illustrates an atomic absorption/metal evaporation rate calibration curve for Fe, showing the evaporation rates required to synthesize Co ferrite that is stoichiometric to within 10%. The evaporation rates were determined by a quartz crystal oscillator at the substrate location.
[0018] [0018]FIG. 3 a shows a Co 2p core-level photoemission spectra for Co ferrite and appropriate oxygen plasma assisted MBE grown standards that establish that Co is in the +2 formal oxidation state in Co ferrite.
[0019] [0019]FIG. 3 b shows a Fe 2p core-level photoemission spectra for Co ferrite and appropriate OPA-MBE grown standards that establish that the majority of the Fe is in the +3 formal oxidation state in Co ferrite. The remainder is in the +2 oxidation state.
[0020] [0020]FIG. 4 a shows a RHEED pattern for an MgO(001) substrate in the [100] direction.
[0021] [0021]FIG. 4 b shows a RHEED pattern for an MgO(001) substrate in the [110] direction.
[0022] [0022]FIG. 4 c shows a RHEED pattern for a 100 nm thick Co ferrite film in the [100] direction.
[0023] [0023]FIG. 4 d shows a RHEED pattern for a 100 nm thick Co ferrite film in the [110] direction.
[0024] [0024]FIG. 5 graphically illustrates an in-plane coercive field as a function of temperature of a 100 nm thick Co ferrite epitaxial film on MgO(001).
DETAILED DESCRIPTION OF THE INVENTION
[0025] [0025]FIG. 1 schematically illustrates an example of an MBE system 100 that can be used in producing the spinel-structured metal oxide on a substrate of the present invention. This MBE system 100 comprises a growth chamber 110 having a combination of electron beam evaporator sources 120 and effusion cells 130 for the metals, and an electron cyclotron resonance (ECR) oxygen plasma source 140 for the activated oxygen. Single-pocket electron beam evaporator sources are preferred because simultaneous evaporation and independent detection is needed to grow binary or ternary metal oxides. Electron beam evaporator sources 120 are typically used for more refractory metals, whereas high-temperature effusion cells (up to 1500° C.) are typically used for more volatile metals.
[0026] An atomic absorption spectroscopy (AAS) detection system (not shown, but described in C. Lu, Y. Guan, J. Vac. Sci. Technol. A 13 (3) 1797, May/June 1995, incorporated by reference herein to the extent not inconsistent with the disclosure herewith) was used for determining, monitoring, and controlling metal evaporation rates and metal deposition rates on the substrate 150 . Optical ports 160 for the AAS detection system were located directly above the metal source crucible openings in order to obtain the maximum AAS signal at low evaporation rates. The AAS signal was then used as a closed-loop feedback control signal for the electron beam evaporator sources 120 , thereby stabilizing the rates from what can be rather unstable sources. In contrast, the effusion cells 130 are temperature controlled due to their greater stability. A single quartz crystal oscillator (not shown) was built into the MBE system 100 and could be moved to the substrate position to calibrate the AAS detection system when there was no oxygen in the growth chamber 110 .
[0027] Besides reducing the hardware requirements within the MBE system 100 , the AAS detection system significantly reduced the ambiguities created by the exclusive use of a quartz crystal oscillator (QCO) to determine deposition rates and provided the monitoring and control resolution necessary for the present invention. That is, a QCO works on the principle that the natural oscillation frequency of the quartz crystal changes as material is deposited on the crystal, not the substrate 150 , surface. Specific properties of the deposit material, such as density and Young's modulus, must be programmed into the controller in order to interpret this frequency change in terms of film thickness. However, there is ambiguity about what is being deposited on the crystal surface in a metal oxide MBE experiment. It might be the metal, or a mix of the metal and various oxides of the metal, or all metal oxide(s), depending on where the QCO is located relative to the substrate 150 and the oxygen source. Furthermore, the mix of deposit materials may change with differing oxygen partial pressures in the growth chamber 110 . In addition, the sticking coefficients of the metal/metal oxide species on the QCO may be different than those on the substrate 150 . The former is held at room temperature, whereas the latter is typically at some elevated temperature.
[0028] In contrast, an AAS detection system relies on a gas phase measurement that depends only on the density of the atomic species of interest in the optical path. All of the optics were outside the growth chamber 110 , so the AAS detection system could be used to determine, monitor, and control metal evaporation rates and deposition rates on the substrate 150 in a highly reliable and accurate fashion.
[0029] The AAS detection system was calibrated using a QCO that was positioned at the same position as that occupied by the substrate 150 during growth. The metal deposition rate was then converted into a growth rate for the oxide of interest by calculating a conversion factor relating the number of metal atoms per cm 2 in each Å of metal to the number of metal ions per cm 2 per layer in the cation sublattice of the metal oxide, assuming a sticking coefficient of unity for the metal in the oxide film. This assumption is expected to be valid for growths carried out at substrate temperatures that are well below the desorption temperatures of either the metal or its oxides. The atomic absorption of the metal species in the gas phase was then directly related to the actual growth rate of the metal oxide film. It was found that the film thicknesses predicted in this way agreed with those measured ex situ after growth by Rutherford Backscattering Spectroscopy or Transmission Electron Microscopy to within ˜10%.
[0030] The substrate 150 was heated to a growth temperature by electron beam bombardment from the backside. The heaters (not shown) were located on the manipulator docking stages. A reflection high-energy electron diffraction (RHEED) gun 170 was used as a real-time structural and surface-morphological probe of film growth. The growth chamber 110 was also coupled to two other chambers (not shown) housing atomic force and scanning tunneling microscopy (AFM and STM) and x-ray photoelectron spectroscopy and diffraction (XPS and XPD) capabilities by means of a 7 m long transfer tube. The AFM/STM was a Park Instruments VP microscope that was specially modified to receive Thermionics sample platens via ultra-high vacuum (UHV) transfer. The XPS/XPD chamber housed a Gammadata/Scienta 200 mm energy analyzer with multichannel detector and monochromatic Alkα X-ray source along with a He resonance lamp and reverse-view low-energy electron diffraction (LEED) optics. This spectrometer was used to perform scanned-angle XPD, as well as ultraviolet photoemission spectroscopy (UPS) and XPS. This selection of surface science tools, in combination with oxygen plasma-assisted MBE, allowed a wide range of metal oxide crystalline films to be synthesized and characterized, all in one UHV environment.
EXAMPLE
[0031] The magnetic anisotropy of bulk crystalline Co ferrite is approximately 30 times larger than that of isostructural Ni ferrite (NiFe 2 O 4 ) and 20 times larger than that of magnetite. The enhanced magnetic properties of Co ferrite essentially result from an unquenched orbital magnetic moment exhibited by Co(II) ions at octahedral sites in the asymmetric crystalline field. Co(II) exhibits this enhancement when in the octahedral field of oxygen anions, with Fe(III) cations as next-nearest neighbors. This local environment is unique to the Co ferrite inverse spinel structure and can be achieved in deposited films by ensuring that the deposited Co atoms are in the thermodynamically stable octahedral lattice sites of the Co ferrite (i.e., the Co atoms are in the equilibrium state).
[0032] A specific example of the present invention is provided herein. In this example, a Co ferrite film on a substrate was made in accordance with the present invention and resulted in desirable properties including magnetic and surface smoothness. For example, the Co ferrite film exhibited excellent hysteresis, with 40% remanence at room temperature and 65% remanence at 150K. No post-growth annealing treatment was required. The as-grown film formed a perfect inverse spinel structure, with greater than about 90% of the Co(II) at octahedral sites in the lattice (that is, in thermodynamically stable positions), and the resulting surfaces were atomically flat.
[0033] As is evident to those skilled in the art, the present invention is not limited to such an example and other metal oxide films may be formed on substrates in accordance with the present invention to exploit magnetic, as well as other, properties resulting from growth in a substantially equilibrium state. Furthermore, the present invention is not limited to utilization of an AAS detection system. Other detection systems may be used to control deposition rates as long as such systems have similar or improved reliability, accuracy, and resolution.
[0034] Important to successful thin-film growth of Co ferrite is the ability to control the absolute evaporation rates of Fe and Co, as well as the activated oxygen partial pressure at the substrate. In this example, the previously described MBE system 100 and experimental setup were used to produce the spinel-structured metal oxide of Co ferrite. FIGS. 2 a - 2 b illustrate atomic absorption/metal evaporation rate calibration curves for Co and Fe, respectively, showing the evaporation rates required to synthesize stoichiometric Co ferrite (to within 10%) at the same total metal deposition rate used to synthesize stoichiometric Fe 3 O 4 .
[0035] An MgO(001) substrate that had been ultrasonically degreased in acetone and isopropanol (5 minutes each) was placed into the MBE system 100 . The ECR oxygen plasma source 140 was ignited and the substrate 150 was exposed to the plasma for a few minutes at a pressure from 1×10 −5 torr to 1×10 −3 torr, and a power level from 200 W to 220 W, in order to remove adventitious carbon from the surface of the substrate 150 . The substrate 150 was brought up to a growth temperature of between 150° C. and 350° C. 250° C. was preferred to maximize crystalline quality while minimizing Mg outdiffusion from the substrate 150 .
[0036] The oxygen chamber pressure was then lowered to 1×10 −5 torr and the plasma forward power lowered to 200 W (in order to get in the middle of the Fe 3 O 4 region of the growth parameter space). The Fe and Co atom beams were then activated (from either the electron beam evaporator sources 120 or effusion cells 130 ) so that the absolute evaporation rates of Co and Fe at the substrate 150 were 0.16±0.02 and 0.34±0.02 Angstroms per second, respectively. The Fe and Co shutters were both opened simultaneously and the Co ferrite grown on the substrate 150 until the desired thickness was reached. The growth rate for Co ferrite under these conditions was ˜1.2 Angstroms per second. The use of a relatively slow growth rate and a modest substrate temperature allowed the Co atoms to diffuse to their preferred equilibrium, or thermodynamically stable, positions within the octahedral layers, assume a +2 oxidation state, and form a perfect inverse spinel structure. The growth was terminated by simultaneously closing both Fe and Co shutters and turning off the ECR oxygen plasma source 140 . The sample remained at growth temperature until the residual oxygen was pumped out to a chamber pressure of <˜1×10 −7 torr, in order to prevent oxidation of Co(II) ions in the near surface region to Co(III). The sample was cooled slowly (1 degree C per second) down to room temperature and helped to prevent film delamination.
[0037] An objective in this example was to synthesize a perfect inverse spinel structure, in which all Co would be in the +2 formal oxidation state, and would occupy half the octahedral cation sites. The other half of the octahedral cation sites, as well as all tetrahedral cation sites, would be occupied by Fe(III). FIGS. 3 a - 3 b show high-resolution Fe 2p and Co 2p core-level spectra for the grown Co ferrite film and appropriate MBE grown standards that illustrated that this method generated the desired oxidation states for both Co and Fe. Comparison of the Co 2p spectrum for Co ferrite with that of the two reference films (CoO and γ-CO 2 O 3 ) reveals that all Co is in the +2 oxidation state. Comparison of the Co ferrite Fe 2p spectrum with those of standard films reveals a better match to γ-Fe 2 O 3 than to Fe 3 O 4 . However, the match is not perfect, and direct superposition reveals the presence of some Fe(II) in the Co ferrite film. This conclusion is further supported by Fe L-edge XAS results. This particular film was shown to have a composition of Co 0.9 Fe 2.1 O 4 and is therefore slightly Fe rich. As a result, some Fe(II) is present in the octahedral cation sublattice at sites that would normally be occupied exclusively by Co(II) if the stoichiometry was exactly Co 1.00 Fe 2.00 O 4 . The presence of Co(II) and Fe(III) in the lattice suggests that the inverse spinel structure has been achieved. However, structural determination by XPD had been inconclusive regarding the lattice site occupancies of Co and Fe. Co and Fe K-shell extended x-ray absorption fine structure (EXAFS) measurements at Stanford Synchrotron Radiation Laboratory (SSRL) have been carried out and conclusively show that 100% of the Co(II) is at octahedral sites, with the remainder of the octahedral sites being occupied by Fe(III) and a small residual of Fe(II). All tetrahedral sites ace occupied by Fe(III). Thus, there is no Co(II) at tetrahedral sites, and a perfect inverse spinel crystalline film has been grown.
[0038] Structural and surface morphological studies by RHEED, XRD and AFM revealed excellent crystallinity and atomically flat film surfaces. FIGS. 4 a - 4 d show typical RHEED patterns for the substrate and film surfaces that revealed both the extent of crystallographic order and flatness of the film surface. The new diffraction streaks seen in the film patterns are characteristic of the factor-of-two difference in the lattice parameters for MgO and Co ferrite. AFM images (not shown) reveal root-mean-square roughnesses of only 0.1-0.2 nm for 100 nm thick films, which is considerably better than that published for PLD-grown Co ferrite. In addition, out-of-plane XRD rocking curves obtained with nonmonochromatic Cu Ka x-rays revealed full-width at half-maximum values of ˜0.09 degrees, which indicates excellent crystallinity within the bulk of the film.
[0039] Finally, magnetic force microscopy (MFM) images revealed large, stable magnetic domains of lateral dimension ˜140 nm for 100 nm thick films. In addition, superconducting quantum interference device (SQUID) hysteresis loops showed in-plane magnetic remnances of 65% and 40% at 150K and 300K, respectively, for a field orientation along [100]. The in-plane coercive field as a function of temperature showed very high values at low temperatures (e.g. >14 KOe at 125K), but also ˜1 KOe at 350K, revealing that the Curie temperature is above 300K (see FIG. 5) Thus, the material shows excellent promise, for example, as a pinning layer in read/write devices that would operate at, or above, room temperature.
Closure
[0040] While embodiments of the present invention have been shown and described, it will be apparent to those skilled in the art that many changes and modifications may be made without departing from the invention in its broader aspects. The appended claims are therefore intended to cover all such changes and modifications as fall within the true spirit and scope of the invention. | A method of making a spinel-structured metal oxide on a substrate by molecular beam epitaxy, comprising the step of supplying activated oxygen, a first metal atom flux, and at least one other metal atom flux to the surface of the substrate, wherein the metal atom fluxes are individually controlled at the substrate so as to grow the spinel-structured metal oxide on the substrate and the metal oxide is substantially in a thermodynamically stable state during the growth of the metal oxide. A particular embodiment of the present invention encompasses a method of making a spinel-structured binary ferrite, including Co ferrite, without the need of a post-growth anneal to obtain the desired equilibrium state. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a device for measuring the velocity of a fluid and more particularly to the measurement of the velocity of gas or air flowing in a confined duct.
2. Description of the Prior Art
Over the years it has become necessary to obtain precise measurements of the flow rate of a fluid such as air or gas through a duct. Usually, these flow rate measurements are required in order to control the pressure, volume, temperature or velocity of the fluids. The flow rate in a duct can be different at different positions in the duct. The physical structure of the duct may even make the flow rate different at different positions in a single transverse plane extending through the duct. Accordingly, the measuring devices of the prior art experienced different flow rate measurements depending upon the physical structure of the duct and the location of the measuring device within the duct.
One partial solution to the problem with respect to the measurement of gas flow in a duct can be seen from U.S. Pat. No. 4,602,514, issued to H. Kurrle, et al. on July 29, 1986, which patent is hereby incorporated by reference herein. The Kurrle patent uses a series of spaced collecting pipes with each pipe having a number of apertures therein for collecting the flowing gas in a duct. The gas flowing into the apertures is funneled to a central point and the volume of the collected gas is measured. The Kurrle patent incorporates rectangular collecting pipes and fins for directing the flowing gas into the apertures of the collecting pipes. Unfortunately, the rectangular collecting pipes and fins of the Kurrle patent distorts the quantity of the gas flowing into the apertures of the collecting pipes.
Thus, there is a need in the art for an accurate velocity measuring device capable of mounting within a fluid carrying duct and capable of sampling the fluid within the duct without regard to the internal structure of the duct. There is a further need in the art for a fluid measuring device having a fluid gathering structure which does not interfere significantly with the fluid flow in the duct.
Therefore, it is an object of this invention to provide an improved sensor for determining the velocity of fluid movement incorporating receiving means for receiving samples of fluids and for communicating the received fluid samples to a manifold and wherein the fluid samples to flow unimpeded through the manifold to a velocity measuring device.
Another object of this invention is to provide an improved sensor for determining the velocity of fluid movement incorporating receiving means for receiving samples of fluids and for communicating the received fluid samples to a manifold wherein fluid samples received by the receiving means communicates to the manifold without restricting the volume of fluid flow from the receiving means.
Another object of this invention is to provide an improved sensor for determining the velocity of fluid movement incorporating receiving means includes a plurality of arms with each arm having a plurality of inlet apertures.
Another object of this invention is to provide an improved sensor for determining the velocity of fluid movement incorporating receiving means includes a plurality of arms with each arm having a plurality of inlet apertures and wherein the cross-sectional area of the receiving means as a function of the cross-sectional area of the apertures.
Another object of this invention is to provide an improved sensor for determining the velocity of fluid movement incorporating receiving means having inlet apertures dispersed within a duct parallel to the fluid flow within the duct.
Another object of this invention is to provide an improved sensor for determining the velocity of fluid movement which is suitable for use for with a variety of conventional velocity measuring devices.
Another object of this invention is to provide an improved method for determining the velocity of fluid movement incorporating the steps of receiving within a plurality of inlet apertures samples of the fluids, communicating the received fluid samples to a manifold, combining the fluid samples within the manifold without restricting the volume of fluid received by the manifold and delivering the combined fluid samples unimpeded to a velocity measuring device.
Another object of this invention is to provide an improved sensor for determining the velocity of fluid movement which is low in cost, highly accurate and reliable.
The foregoing has outlined some of the more pertinent goals of the present invention. These goals should be construed to be merely illustrative of some of the more pertinent features and applications of the invention. Many other beneficial results can be obtained by applying the disclosed invention is a different manner or modifying the invention within the scope of the disclosure. Accordingly, a fuller understanding of the invention may be had by referring to the summary of the invention and the detailed description describing the preferred embodiment in addition to the scope of the invention defined by the claims taken in conjunction with the accompanying drawing.
SUMMARY OF THE INVENTION
The invention is incorporated in the apparatus and method of determining the velocity of fluid movement. For the purposes of summarizing the invention, the invention is incorporated into a sensor for determining the velocity of fluid movement, the sensor comprising a manifold through which samples of the fluid can flow and receiving means for receiving samples of fluids and for communicating received fluid samples to the manifold. The receiving means includes a plurality of inlet apertures arranged into groups with each the group of inlet apertures receiving the fluid samples and communicating the fluid samples to the manifold via an individual one of the receiving means. The volume of fluids which can physically pass through the group of apertures associated with each the receiving means is physically restrained to be equal to or less than the volume of fluids which can be communicated by each the receiving means. The manifold is established for combining fluid samples received by the inlet apertures and communicated to the manifold without restricting the volume of fluid flow from the receiving means. The combined fluid samples flow unimpeded through the manifold to a velocity measuring device. The present invention is suitable for use with a variety of conventional velocity measuring devices.
In more specific embodiment of this invention, the cross-sectional area of the apertures is controlled to be a function of the cross-sectional area of the receiving means. In one embodiment, the receiving means includes a plurality of arms and wherein the controlling function between the diameter, and hence the cross-sectional area, of each the inlet aperture and the inside diameter, and hence the cross-sectional area, of each the arm is given by the formula D I =D A /√ I , where D I =diameter of inlet aperture, D A =inside diameter of the arm and N I =number of inlet apertures. The receiving means includes a plurality of arms and wherein the controlling function between the diameter, and hence the cross-sectional area, of each the arm and the inside diameter, and hence the cross-sectional area, of each the aperture is given by the formula D A =D I √ I , where D A =inside diameter of the arm, D I =diameter of inlet aperture and N I =number of inlet apertures. The inlet apertures dispersed within the duct are established perpendicular to the fluid flow within the duct. More specifically, the receiving means are a plurality of tubes having an open end and a closed end and wherein the manifold is a substantially hollow structure having apertures constructed in the sides thereof, the last-mentioned apertures adapted to accept the open end of the tubes. The manifold apertures are disposed on four opposite faces of the manifold and wherein the tubes are bent so that the closed ends of all four tubes lie along the flow direction of the fluid when the tubes are in mated relationship with the manifold apertures.
The invention is also incorporated into the method of determining the velocity of fluid movement, the method comprising the steps of receiving within a plurality of tubes via a plurality of inlet apertures arranged into groups, each group associated with one of the tubes, samples of fluids to be measured and communicating received fluid samples to a manifold central to all the receiving tubes, without restricting the volume of fluid received by the totality of all the inlet apertures. The method includes combining the communicated fluid samples within the manifold without restricting the volume of fluid received by the manifold from all the tubes delivering the combined fluid samples unimpeded to a velocity measuring device.
The fluid gathering principals inherent with using a plurality of extended tubes within a fluid carrying duct have been applied to design a fluid velocity sensor. Fluid gathering apertures are located on the tubes which extend radially outward from the central fluid gathering manifold. The apertures of each tube are constructed such that the sum of their fluid gathering openings is equal to, or less than, the inside fluid handling capacity of the tube. The central gathering manifold, in turn, has fluid handling capacity equal to the sum of the capacities of the fluid handling tubes. In this manner, back pressure does not affect the velocity of the fluid passing through the central gathering manifold. Fluids which pass though the tube apertures and into the central gathering port then flow past a velocity sensor.
The foregoing has outlined rather broadly the more pertinent and important features of the present invention in order that the detailed description of the invention that follows may be better understood so that the present contribution to the art can be more fully appreciated. Additional features of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and the specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawing in which:
FIG. 1 shows a perspective view of the inventive sensing device having fluid gathering arms, a central gathering manifold, and a velocity measuring device;
FIG. 2 is a sectional view taken along line 2--2 of FIG. 1 showing internal details of one specific velocity measuring device suitable for use with the present invention;
FIG. 3 is a sectional view taken along line 3--3 of FIG. 1 showing internal details of the central gathering manifold; and
FIG. 4 shows various formulas used to show relationships.
Similar reference characters refer to similar parts throughout the several views of the drawings.
DETAILED DESCRIPTION
FIG. 1 is an exploded view of a fluid velocity sensing device 10 of the present invention which is designed to be disposed within a duct (not shown) such as an air conditioning or heating duct. The fluid velocity sensing device 10 comprises a central manifold 11, a velocity measuring unit 12 and receiving means 13 shown as a plurality of hollow fluid gathering arms 13A, 13B, 13C and 13D. Each of the plurality of fluid gathering arms 13A 13B, 13C and 13D of FIG. 1 are hollow and extend from the central manifold 11. Preferably, each of the plurality of fluid gathering arms 13A, 13B, 13C and 13D are frictionally received in apertures 14A, 14B, 14C and 14D of the central manifold 11. An outer end 16A, 16B, 16C and 16D of the plurality of fluid gathering arms 13A 13B, 13C and 13D are closed to inhibit fluid flow therethrough.
Each of the plurality of fluid gathering arms 13A, 13B, 13C and 13D includes inlet means shown as a plurality of inlet ports 15. Fluid gathering arms 13A includes inlet ports 15A-1, 15A-2, 15A-3 and 15A-4 whereas fluid gathering arms 13B includes inlet ports 15B-1, 15B-2, 15B-3 and 15B-4. In a similar manner, fluid gathering arms 13C includes inlet ports 15C-1, 15C-2, 15C-3 and 15C-4 whereas fluid gathering arms 13D includes inlet ports 15D-1, 15D-2, 15D-3 and 15D-4.
When the plurality of fluid gathering arms 13A, 13B, 13C and 13D are frictionally received in apertures 14A, 14B, 14C and 14D of the central manifold 11, the inlet ports 15A-1, 15A-2, 15A-3, 15A-4, 15B-1, 15B-2, 15B-3, 15B-4, 15C-1, 15C-2, 15C-3, 15C-4, 15D-1, 15D-2, 15D-3 and 15D-4 lie perpendicular to the fluid flow direction as shown by the arrow. The combined opening areas of the four inlet ports in each of the fluid gathering arms is constructed to be equal to, or less than, the cross-sectional area of the inside of the fluid gathering arm. For example, the combined area of inlet ports 15A-1, 15A-2, 15A-3 and 15A-4 is equal to, or less than, the cross sectional area of the inside of the fluid gathering arm 13A.
As it will become apparent from the preferred design parameters set forth hereinafter, the number of inlets ports per fluid gathering arm is not critical. The relationship of the combined opening areas of the inlets ports per fluid gathering arm to the internal cross-sectional area of the fluid gathering arm is a critical factor. Preferably, diameter of each of the inlet ports is less than one-third the outer diameter of the fluid gathering arm. This relationship of the diameter of the inlet port to the outer diameter of the fluid gathering arm insures that the fluid flow enters the inlet ports in less turbulent manner. In contrast to the prior art, each of the fluid gathering arms is circular in cross-section without any directing fins. The circular cross-section and absence of fins provides a fluid flow into the inlet parts which is representative of the fluid flow within the duct.
FIG. 2 is a sectional view of the particular velocity measuring unit 12 shown in FIG. 1 but it should be understood that numerous other types and varieties of velocity measuring units may be suitable for use with the present invention. The velocity measuring unit 12 is of a standard design and should be well known to those skilled in the art. The velocity measuring unit 12 includes a channel 20 for receiving the flowing fluid. The flowing fluid passes through channel 20 and move past sensors tubes 21-1 and 21-2. The sensors tubes 21-1 and 21-2 are respectively connected to terminal ports 22-A and 22-B by means not shown. A second flow of fluid is established perpendicular to the flow of the fluid through channel 20 from sensor tube 21-1 to sensor tube 21-2 through terminal ports 22-A and 22-B by external means (not shown). The fluid flow through channel 20 deflects the second flow of fluid from sensor tube 21-1 to sensor tube 21-2 to alter the flow rate of the second fluid flow between terminal ports 22-A and 22-B. Accordingly, a variation in the flow rate of the fluid passing through channel 20 produces a variation in the deflection of the second flow of fluid from sensor tube 21-1 to sensor tube 21-2 and varies the flow rate of the second fluid flow from terminal port 22-A to terminal port 22-B. A measurement of the second flow rate of the second fluid flow between terminal ports 22-A and 22-B is indicative of the flow rate of the fluid passing through channel 20. The velocity measuring device set forth above is manufactured by Honeywell under the trademark "Velocitrol" (Part No. CP980).
FIG. 3 is a partial sectional view along line 3-3 of the fluid velocity sensing device 10 of FIG. 1. The manifold 11 includes a manifold port 25 which is in fluid communication with apertures 14A, 14B, 14C and 14D of the central manifold 11. A relief 30 in the manifold port frictionally receives the velocity measuring unit 12 and to communicate the manifold port 25 with channel 20. The moving fluid enters inlet ports 15A-1, 15A-2, 15A-3, 15A-4, 15B-1, 15B-2, 15B-3, 15B-4, 15C-1, 15C-2, 15C-3, 15C-4, 15D-1, 15D-2, 15D-3 and 15D-4 and flows through fluid gathering arms 13A 13B, 13C and 13D to enter apertures 14A, 14B, 14C and 14D of the central manifold 11. The moving fluid exits from apertures 14A, 14B, 14C and 14D and flows through manifold port 25 into channel 20. The manifold port 20 has an inside cross-sectional area A M which is equal to four times the inside cross-sectional areas of the fluid gathering arms 13A 13B, 13C and 13D. Accordingly, the fluid velocity sensing device 10 has a constant cross-sectional area from the inlet ports 15A-1, 15A-2, 15A-3, 15A-4, 15B-1, 15B-2, 15B-3, 15B-4, 15C-1, 15C-2, 15C-3, 15C-4, 15D-1, 15D-2, 15D-3 and 15D-4 to the channel 20 of the velocity measuring unit 12. The constant cross-sectional area of the fluid velocity sensing device 10 insures that there is no pressure increase or back pressure due to the design of the fluid velocity sensing device 10 as was found in the prior art devices. In addition, the distribution of the inlet ports 15A-1, 15A-2, 15A-3, 15A-4, 15B-1, 15B-2, 15B-3, 15B-4, 15C-1, 15C-2, 15C-3, 15C-4, 15D-1, 15D-2, 15D-3 and 15D-4 over a wide area of a duct insures that an accurate measurement is made of the velocity of the fluid in the duct.
FIG. 1 also illustrates a side bore 34 closed by a plug 36 in the central manifold 11 for receiving a velocity measuring device known as a thermo-anemometer or a hot wire fluid flow measuring device which should be well known to those skilled in the art. In a hot wire fluid flow measuring device (not shown), a wire is heated by an electrical current. The flow of the fluid through manifold 11 cools the heated wire in the hot wire sensor to vary the electrical current flow through the hot wire in accordance with the flow rate of the fluid through manifold 11. A detector (not shown) of conventional design, senses the current flow to indicate the flow rate of the fluid through manifold 11. One particular hot wire velocity measuring device as set forth above is known as an Alnor 8500. It should be appreciated by those skilled in the art that a pneumatic velocity measuring device such as the "Velocitrol" or the hot wire sensor velocity measuring device such as the Alnor 8500 or any equivalent type of types of velocity measuring device is suitable for use with the present invention.
FIG. 4 illustrate equations which may be used by one skilled in the art to design the fluid velocity sensing device 10 of the present invention to have the proper relative cross-sectional areas, given at least one of the cross-sectional variables, plus the number of fluid gathering arms 13 arms and number of inlet ports 15. For example, the diameter of the inlet ports (D I ) can be determined by equation C once one decides upon the diameter of the central manifold (D m ) and has determined the number of arms (N A ) there are to be and the desired number of inlets (N I ) per arm. Using equation D one can determine the diameter of the manifold (D m ) given the diameter of each inlet (D I ) hole, the number of such holes (N I ) and the number of arms (N A ).
For example, if the inside diameter of fluid gathering arm 13C is assumed to be 0.25 inches then the cross sectional area of the fluid gathering arm would be 0.049 square inches. This comes from the well-known formula shown in FIG. 4A. Accordingly, if the fluid gathering arm has four inlets ports having equal openings, each inlet port would then have an area of 0.01225 square inches. This translates to a diameter of 0.125 inches for each inlet port. This relationship is simplified and shown in FIG. 4G where D A (diameter of the fluid gathering arm) is assumed to be 0.25 square inches and N I (number of inlets ports per fluid gathering arm) is assumed to be 4.
Thus, in our example where there are four fluid gathering arms (N A =4), each having a cross-sectional area of 0.049 square inches, the combined cross-sectional area A M of the manifold port 25 of manifold 11 would be 0.196 square inches. This results in a diameter (D M ) for the manifold port 25 of 0.5 inches.
The present disclosure includes that contained in the appended claims as well as that of the foregoing description. Although this invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example and that numerous changes in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention. | A device for measuring the velocity of a fluid such as gas or air, traveling through a duct, which device relies upon a series of precisely controlled apertures for gathering a plurality of fluid samples and presenting the summation of the samples to a central velocity sensor. The device precisely controls the volume of the fluid which can flow across the sensor, thereby preventing pressure gradients within the measuring device from modifying the velocity measurements. | 6 |
BACKGROUND AND SUMMARY OF THE INVENTION
The invention refers to a nano granular material (NGM) comprising electrically conducting nano crystals embedded in an insulating matrix and surrounding layer. The material carries a high current density by variable range hopping, of electrons between the nano crystals.
U.S. Pat. No. 6,246,055 discloses a nano granular material as well as a photon detector made thereof, which delivers at low light photon quantities and energies usable for signals. The photon detector is partly composed from a nano-crystalline phase and is included in an insulating carbon matrix and which is producible with simple production machines and processes. The production of similar materials using organometallic precursors is described in: H. W. P. Koops, A. Kaya, M. Weber. “Fabrication and Characterization of Platinum nano crystalline Material Grown by Electron-beam Induced Deposition”, J. Vac. Sci. Technol, B 13(6) November/December (1995) 2400-2403. High resolution Transmission-electron microscope image at 200 kV reveals 12 to 14 lattice planes of the platinum or gold single crystals of 0.408 nm distance. 800 to 1000 atoms form a perfect crystal embedded into a Fullerene matrix.
Crystal sizes are for Au/C: 3-4 nm obtained from Dimethyl-Gold-Trifluoro-Acetylacetonat, and for Pt/C: 1.8-2.1 nm deposited from Cyclopentadienyl-Platin-trimethyl. [J. Kretz, M. Rudolph, M. Weber, H. W. P Koops, “Three Dimensional Structurization by Additive Lithography, Analysis of Deposits using TEM and EDX, and Application for Field Emitter Tips” Microelectronic Engineering 23 (1994) 477-481]
However, there the matrix in Au/C and Pt/C materials is from Fullerene and presents a 2-D resistor surrounding the NGM material having a Fullerene matrix. This matrix is over the time of use etched away by water and activated gas ions. This limits the lifetime of the detector.
It is desirable to have a nano granular material with extraordinary properties like high current conductivity and radiation sensitivity with a long lifetime.
According to an aspect of the invention this task is solved by high current density carrying nano granular material comprising conducting nano crystals embedded in a matrix, wherein the matrix consists of insulating carbon-free material. Preferably the insulating material is an oxide, oxy-nitride or nitride. Even semiconductors can be used if they are insulating by surface depletion by their small layer thickness.
This invention is strictly different from the one taught in e.g. US Photo detector patent U.S. Pat. No. 6,246,055 B1. There the nano crystalline material is produced from organometallic precursors and has a carbonaceous matrix of low conductivity. Such a material is destroyed by a reaction of the carbonaceous compounds in the matter and in the surrounding surface, which takes place in the presence of excited water or gas atoms which are delivered from the environment and excited by the electromagnetic radiation, which is to be detected.
The carbon-free matrix and coating prevents in an advantageous way the destruction of the current leading wire or sheet, switch, photo detector, or solar cell due to reaction with surrounding materials like water or atmospheric gases, which are excited by the impinging energetic photons.
The material according to an aspect of the invention enables many applications and new electrical components, whereby a separation between the nano crystals is smaller than 2 nm. If required in particular cases the separation can be made larger, e. g. up to 5 nm.
In a preferred electrical component the material is shaped as a thin layer, having an entrance plane for radiation and electrodes for applying, an electrical field to the material.
In one embodiment of this inventive component said electrodes are electrically connected to the material. Such component can be used as detector for visible light, ultraviolet radiation or X-rays.
In another embodiment of this inventive component said electrodes are electrically insulated from the material and further collectors are electrically connected to opposite edges of the material. Exited by a weak electrical field provided by the insulated electrodes incident light causes the electrons to flow to one of the collectors at d the holes to flow to the other one of the collectors. Therefore this embodiment is a high efficient solar cell. Detailed explanations follow in connection with the drawings.
In another electrical component comprising material according to an aspect of the invention the material forms field emitter tips being arranged in vacuum cells which are formed by two planes, at least one of which is transparent for photons, and spacers between the planes, the transparent plane is covered with a luminescent layer in each cell, said field emitter tips are arranged opposite to the luminescent layers and the spacers carry an accelerator grid. This component generates light very effectively.
In a further development of this electrical component said cells form groups having luminescent layers of different colors within each group. This enables different colors of the light at the application as a light source e or as a display, if said field emitter tips or groups of said field emitter tips can be activated separately from each other.
To improve focusing of the emitted electrons in this electrical component an extractor can be attached to each of said field emitter tips.
A further embodiment of the electrical component can serve as radiation detector wherein the material forms field emitter tips which are arranged on a transparent support plane with tip structures and wherein the field emitter tips emit electrons which occupy the excited excitonic levels being lifted to those energy levels by incident photons of IR-, visible-, or X-radiation due to the extraction voltage between the emitter tips and a micro channel plate and co-act with a charge detector array through the micro channel plate.
Another embodiment of the electrical component forms a high voltage and high current switch, wherein the material forms an array of field emitter tips being arranged as cathode at one end of a vacuum tube and wherein the vacuum tube comprises further an anode and near the cathode an extractor. Preferably the extractor is arranged co-planar to the cathode or below (opposite to the anode) an insulating layer carrying the cathode and is used to switch the emission with a low voltage. This embodiment can further be improved by at least one accelerator dynode.
In an advantageous method for manufacturing material according, to an aspect of the invention a high energy electron, ion or photon beam is directed on a sample producing secondary electrons, wherein multiple inorganic molecules and metallic precursor gas are supplied, which are dissociated by said secondary electrons resulting in the deposition of the insulating matrix and metallic nano crystals embedded therein.
An arrangement for manufacturing material according to an aspect of the invention comprises in a vacuum chamber an electron, ion or photon beam source as a deposition system and a computer controlled multiple inorganic molecules and metallic precursor gas supply system.
An arrangement for manufacturing electrical components according to an aspect of the invention with areal field emitter tips comprises in a vacuum chamber an electron, ion or photon beam reducing image projection systems as a deposition system having a computer controlled multiple inorganic molecules and metallic precursor gas supply system in a structured fashion to define areal arrangements of field emitter tips.
The invention, according to an aspect thereof, relates further to an arrangement for manufacturing elongated forms of material according, to an aspect of the invention, which comprises in a vacuum chamber an electron, ion or photon beam source as a deposition system and a computer controlled multiple inorganic molecules and metallic precursor gas supply system and comprises further a transport system for the elongated material in order to move the material through a reaction area. Preferably this arrangement comprises means for maintaining temperature of the material in the reaction area. This solves the problem to deposit large areas of the NGM Material.
Another arrangement for manufacturing material according to an aspect of the invention by electron, ion or photon beam shadow mask image projection system uses a deposition system having a computer controlled multiple precursor gas supply system and the anode drop of a gas discharge areal energy source to deposit in a structured fashion NGM material for arrays of field emission electron or ion sources, for sheets, for long wire deposition, for power cables, for multiple pixel aerial photon detectors, for fast imaging in the IR, visible and X-ray regime, as well as for solar cells. For the purpose of enlarging the area this arrangement can be improved further by an electrostatic or magnetic multi beam deflection capability.
Another advantageous method for manufacturing nano granular materials according to an aspect of the invention uses especially tip arrays replicated with nano-imprint lithography means and then supplied with field emitter tips by high field material deposition using a deposition system having a computer controlled multiple precursor gas supply system, with the refined method of measuring the electron field emission by a computer evaluation of the emission on current during the tip growth process in an intermediate step in very short times compared to the tip growth process and to stop the growth for all parallel growing tips by a computer evaluation of the emission at a defined emission current.
A further development of this method is characterized in that the intermediate measurement of emission characteristics presents also a method to renew all tips by using a deposition system having a computer controlled multiple precursor (more than 1) gas supply system also equipped with halogens to etch all tips in the large area emitter structure and to re-grow the tips to the previous perfection with the high-field chemistry 1, 2 or 3 molecule deposition process.
Such process per se is published in:
M. Bischoff Int. Journal of Electronics 1992, Vol. 73 No. 5, 827-828 H. B. Linden, e. Hilt, H. D. Beckey, J. Phys. E: sci. Instruments. Vol 11 1987 1033 “High rate growth of dentrites on thin wire anodes for field desorption mass spectrometry” J. T. L. Thong “Metallic Nanowires grown via field emission induced growth as electron sources” IVNC 2013 Tech digest 1 21 page 94.
In the following the matrix of the inventive material is referred to as M, e. g. Au/M means gold nano crystals in such matrix.
The invention, according to an aspect thereof, enables material for high current conducting wires and sheets, for bright electron and ion sources, as well as for photon detectors. The task is solved, using an energetic electron impact process, which produces the material fabricated as a nano-crystalline material, which is composed from conducting metal- or metal compound nanocrystals embedded into an insulating oxide, oxinitride or nitride matrix, which also surrounds the material with a non-conducting oxide, oxinitride or nitride layer, or by a semiconducting material which is in its surface states depleted by the small geometry. The nano crystals are having a dimension of smaller than 15 nm diameter and the intermediate insulating layer is thinner than 2 nm between the nano crystals, which is the reason for single charge moving from nano crystal to nano crystal using excited excitonie surface orbital states, which overlap to the ones of neighboring crystals and therefore free electrons and holes can form Bosons which are distributed through all the NGM material.
By the effect called Bose Einstein Condensation (BEC) positive and negative charges can form Bosons, which allows the condensation of many Bosons in one energy level. This is the reason for the very high current densities emitted from field emitter tips and being carried in thin wires at room temperature without destruction. (Literature: L. V. Butov et. al. “Towards Bose-Einstein Condensation of excitons in potential traps” in: NATURE/Vol. 47/47-52, 2. May 2002). Typically metals or metallic compounds have no bandgap in their energy level structure, and therefore cannot present Eigenstates of distinct separation to absorb energy from photons. Si has a bandgap of 1.5 eV and can therefore absorb electromagnetic radiation energy quanta with this value. That leads to ca. 16% effectivity in Si-solar cells in the visible spectrum collecting energy from the sun.
In addition the geometry quantization of the nano-crystals, which have a diameter below 10 nm, prevents that high energy phonons, like in 3-dimensional electron gas materials, like normal crystalline metals or metal alloy conductors, can be excited.
This is due to the fact that inside the nano crystal only 8 to 12 lattice planes exist. The insulating matrix having, a different density than the crystal materials also prevents the impulse transfer to neighboring atom chains. According to Patton and Geller only the lower energy state for acoustic phonons is occupied, which has an energy of 2 meV corresponding to a temperature of 23.2 K or −250° C. (Patton, K. R. & Geller, M. Phonons: in “A nanoparticle mechanically coupled to a substrate”, Phys. Rev. B 67, 155418 (2003).
Therefore photo detectors from such materials do not need an additional power consuming Peltier cooler to reach the detection limit at 8 μm photon wavelength (for the Au/M compound or 4 nm crystal diameter), like commercial infrared cameras need to have.
Due to the fabrication method with an energetic electron impact on adsorbed molecules many for semiconductor photo-detectors required technology fabrication steps are avoided which makes the production of NGM current leads and detectors much cheaper.
Very small amounts of the compound material are sufficient to detect photons. In earlier experiments to measure the effectivity ala photon detector from Au/M deposited from Dimethyl-Gold-Acetylacetonate with the dimensions of 2 mm×50 nm wire width and thickness showed at illumination with a lamp of 60 W power a photocurrent of several nA. Resistive change was 10 MΩ to 3 MΩ. A Voltage change by 2 meV is good for 12 bit image contrast at 1 μV amplifier noise level.
Aerial detectors of 2 μm×2 μm deposited from Pt/M material showed similar results. Recently (not published jet) we measured from Pt/M wires of an area of 0.32 μm 2 an photocurrent of 200 nA illuminating the area of the structure with a power density like the sun sends to the earth of 100 mW/mm 2 . The solar light source delivers to the earth 1.36 kW/m 2 =1.36 10{circumflex over (0)}3/10{circumflex over (0)}4 W/cm 2 =0.136 W/cm 2 =136 W/cm 2 , which is 100 times less than the laser source intensity of our experiment.
Therefore the efficiency of this material, if produced in an aerial coating, would allow converting the energy from the sun with a so far not reached efficiency!
An experiment revealed: red light of 700 nm wavelength (=1.3 eV per quanta) with an intensity of 100 mW/mm 2 releases, if used with an intensity of 100 mW/mm 2 from the deposited area of 3.2 10{circumflex over (0)}-9 cm 2 an electron current density 0.2 μA/3.2 10{circumflex over (0)}-9 cm 2 =2 10−7 A/3.2 10{circumflex over (0)}-9=60 A/cm 2 =60 A/cm 2 . With a voltage difference of 0.12 V this would amount to 60×0.12 W/cm 2 =7.2 W/cm 2 collection efficiency of the Pt/M material. With the solar light source of 136 mW/cm 2 , which is 1/100 of the experimental condition the NGM Material would have collected 72 mW/cm 2 . This is a significantly higher value (around 3), than Si solar cells, which convert 15% of this energy, which is 20.4 mW/cm 2 , when using only yellow to blue light. NGM Pt/M materials efficiency in monochromatic red light is at least a factor of 3 higher than that of Si-solar cells.
Producing the nano granular material with a larger grain size would increase the number of electrons, which are excited by the photon and can tunnel through the NGM material, due to the effect of the reduction of the Eigenstate separation values of the electron orbitals at the crystal surface.
A crystal diameter of 2 nm correspond to an Eigenstate separation of 125 mV, 4 nm to 65 eV, 6 nm to 32.5 meV and 8 nm to 16 meV, which would correspond to a 100 times higher effectivity for electromagnetic radiation conversion compared to silicon or similar solar cells!
Therefore it is a task for the production of the crystals to select the deposition and materials composition conditions in a way that larger crystals are produced in the deposit. This can be achieved using additional reaction partners, which reduce the confining molecules which form the insulating matrix.
For hopping conduction it is necessary that the crystals have a separation from each other which is as small as <2 nm. However, if there is a separation larger than 2 nm, and no hopping conduction is possible, such materials are insulators. One method is to use a gas discharge with ions as it is used to coat tools e.g. with a hard layer of AlTiN with an amorphous Si 3 N 4 insulator matrix material. [Lecture of H. Frank G F E at 3 rd ITG Workshop on vacuum nano electronics at Bad Honnef 19.8.12] The crystals and intermediate oxide or nitride fit the expectations. However, the violet looking materials layers have not been investigated for optical and electrical activity so far.
Another method is to use a multi-source sputter deposition system with material flux control.
Another method is ALD Atomic Layer deposition with Multi-precursor reactions for conductive nano crystals and insulating embedding of the crystal grains in a repeated manner to form NGM material layers of several 100 nm thicknesses.
Another method is to use the as discharge in a large flat chamber to generate fast electrons with the anode fall for electrons to decompose and deposit to a target the adsorbed mixture of inorganic precursor molecules of several compounds as supplied to the gas phase in the discharge. Appropriate inorganic low vapor pressure compounds are the fluorines, or halogenes of Al and Ti, as well as Si. Also other compounds forming mixtures of conducting crystalline material from metals and nitrides or oxides can be used, but they must be selected with their condensation reaction energy which avoids, that they co-condense in an epitaxial way with the insulating phase which is embedding the nano crystals phase.
Typically the crystallographic system of the deposits of the compounds of the crystal core and the surrounding insulator should not match, and for the insulating phase a hindered epitaxy is needed which has an epitaxial temperature below the temperature of the crystals growing temperature.
Another way to fabricate the NGM materials in large areas is to use focused electron beam induced deposition using massive parallel electron beams from gas discharges, thermal source arrays, Thermofield electron source arrays or field emitter arrays produced by semiconductor technology and micromechanical means, especially using tip arrays replicated with nano imprint lithography means and then supplied with field emitter tips by high field material deposition.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows schematically the composition of a Nano granular compound material
FIG. 2 shows in a schematic representation the region of crystal diameters for Coulomb blockade with full electron transitions even at room temperature
FIG. 3 presents the evaluation of surface electron orbitals using Bohr's Eigenvalue estimation from stable electron orbits and oscillations.
FIG. 4 presents a measurement of a light induced current in Pt/M
FIG. 5 is a schematic representation of a field emitter tip of NGM.
FIG. 6 shows a schematic diagram of an arrangement for producing NGM
FIG. 7 is a schematic representation of the effect of an in incident photon,
FIG. 8 shows a solar cell
FIG. 9 shows a current/voltage plot of the photon detector made of NGM.
FIG. 10 shows a field-emitter fluorescent lamp
FIG. 11 shows a field-emitter image display
FIG. 12 shows a high power switch,
FIG. 13 shows an X-ray image detector and
FIG. 14 shows an arrangement for manufacturing a conductor on an area, a wire or a ribbon.
DETAILED DESCRIPTION
The nano granular material shown in FIG. 1 consists of conducting metal crystals which are composed of atoms 3 with interatomic spaces 1 , and the nano crystals are embedded into an insulating, matrix 2 consisting of oxide, oxinitride or nitride.
FIG. 2 shows in a diagram the region of crystal diameters for Coulomb blockade with full electron transitions even at room temperature. The nano granular material has a quantum dot size between 2 and 4 nm and therefore provides discrete charge transfers at room temperature and above, e.g. for Bose-Einstein-Condensation (BEC), and for filling up excitonic orbital levels around crystals with electrons, which come from the at room temperature occupied electronic states above the Fermi level of the metal, which are filled due to the Maxwellian energy distribution of electrons in metals.
FIG. 3 shows for nano granular materials Bohr's Eigenvalue circular states 31 at rim surface orbitals(n1) with <120 meV level splitting an Bohr's Eigenvalue transmission states 32 (m*Lambda/2, with in an integer). The diameter of a nano crystal 33 may be in case of PT/M 2 nm an in case of Au/M 4 nm. In FIG. 3 further surface orbital states n=1, n=2 and n=3 labeled as 34 , 35 , 36 are depicted. These can form excitonic states which are overlapping to the excitonic states from the neighboring crystals and allow electron and holes to be distributed across all the NGM without resistive loss. The energy gap between exetinic orbital states is for Pt/M: 120 meV and for Au/M: 65 meV.
The NGM materials present with every crystal a photon energy trap. Due to the small size of the crystals, many parts of the photon energy can be absorbed by inelastic Raman-Scattering in a thin layer of NGM material, and also in neighboring crystals of the same layer. Therefore NGM materials are very efficient absorbers and require only a thin NGM material layer. This characteristic saves in an advantageous way materials due to the small thickness of the layer needed e.g. for a solar cell, E. g. 10 subsequent absorber levels correspond to a 20 nm layer thickness (Pt/M) or 40 nm (Au/M).
The diagram of FIG. 4 shows the light induced current as measured with an extraction voltage from a Pt/M deposited area of 3.2 10{circumflex over (0)}-15 cm 2 and red laser light illumination of 1.3 eV. A light induced current is measured starting from 0 volts in a field emission diode experiment, giving proof that electrons are released from the crystal by excitation of circular orbit excitonic electron states.
The upper part of FIG. 5 shows schematic representation of a field emitter tip of NGM with metal nano crystals 1 and an embedding insulator matrix 2 as it is displayed by a transmission electron microscope which superimposes all crystal images in one picture. The middle of FIG. 5 represents three potentials and equidistance eigenvalues of electrons in surface orbital of three single crystals with energy levels 6 , tunneling barrier between crystals 7 , tunneling barrier to vacuum 8 , potential difference due to external voltage application 9 , electron at energy level 10 , electron after hopping to next crystal 11 electron after hopping to next crystal 12 . The electron finally leaves the crystal 5 by tunneling through potential 8 as a field emitted electron 13 . The bottom pan of FIG. 5 shows schematic diagrams of the single crystals 3 , 4 , 5 .
FIG. 6 shows a schematic diagram of an arrangement for producing NGM. An electron beam source comprising a field emitter, or a thermofield emitter, a thermal or a gas discharge source, which is made of NGM generates an electron beam 60 which is directed on a substrate or sample respectively 65 . Through a nozzle 66 precursor molecules 67 are supplied. All elements shown in FIG. 6 are arranged in a reaction chamber 610 containing high vacuum of about 10 −4 to 10 −7 mbar. The electron beam 60 generates secondary electrons which react with the precursor molecules 67 supplied through nozzle 66 . This results in cracking the precursor molecules 67 in metallic atoms, which first condense to nano crystals 63 and insulating material, which forms a matrix in which the nano crystals are embedded. Precursor molecules 61 adsorbed precursor molecules 62 Radicals 69 from precursor molecules etched substrate material 64 due to forming of volatile reaction products in the reaction with the excited precursor gas.
FIG. 7 is a schematic representation of the effect of an incident photon. The upper part shows schematically two nano crystals 713 very near to each other with orbits 710 , 711 , 712 , whereby the orbits 710 , 711 of excited electrons, so called excited excitonic states, overlap. The overlapping excited excitonic states are the reason for the Bose-Einstein-Condensation forming Bosons, which are in high density in the level, and allow giant current densities and anomalous high current at room temperature in nano-granular materials with crystal diameters below 5 nm. An incident photon 719 boosts an electron from a lower exciton level 715 to a higher exciton level 714 absorbing energy 720 . Lines 717 and 718 depict the surface and the inner orbital of the nano crystal. By virtue of an electric field 721 the electron on the energy level 714 721 moves to the right while the hole on the energy level 715 moves to the left. Electrons and holes can undergo Bose Einstein Condensation and form Bosons.
On an insulating substrate under energy supply with several eV electrons or ions to adsorbed layers Material deposition or etching, is formed from inorganic precursors containing at least one metal component, or several different metal components, and precursors containing insulator or oxide forming other metals or semiconductors with the influence of other radiation or energy delivering sources, which can also be especially selected to react with the organic components and form a volatile phase which does not condense in the NGM Material.
Deposition conditions are to be selected under the constraint to form nano granular deposits with crystals sizes between 1 nm and <15 nm, and being composed from nano crystals from a conducting metal or metal compound phase being embedded into an non-conducting and insulating phase with a very thin thickness between the crystals e.g. <2 nm.
Metals, semiconductors and their precursor compounds used comprise Beryllium, Boron, Silicon, Gallium, Indium, Germanium, Tin, Lead, Zinc, Iridium, Aluminium, Silver, Gold, Scandium, Titanium, Vanadium, Chromium, Manganese, Iron, Cobalt, Nickel, Copper, Zinc, Cadmium, Thallium, as well as their mixtures and their oxides, nitrides, oxi-nitrides, phosphides, halogens, and mixed metal compounds like Sn Zn Ox e.g. Spinel, Zn Sn Ga, Al Ti N. Insulating matrices being formed from Silicon-oxide, Silicon Nitride, Silicon-Oxi-Nitride and other mixtures of Metal oxides, Nitrides or Phosphines.
FIG. 8 shows a section of a solar cell which converts the energy of electromagnetic radiation, e.g. sunlight, into electric energy. NGM is arranged between a positive collector 734 and a negative collector 740 . A resistor 736 is insulated to the NGM by insulators 735 forming an electric field 737 . Due to the impact of photons 730 on the NGM the electrons get higher energy level and are tunneling through the matrix in the direction which is given by the field 737 . The excitonic electrons 731 move to the positive collector 734 and the excitonic hole to the negative collector 740 . A rest 739 of the photon after energy loss leaves the NGM. As the NGM has a very low resistance the electrons cause a high current. But the voltage generated between the collectors 733 and 740 is relatively low, about 0.06 to 0.16 eV. The efficiency compared with the conventional solar cells is very high. The lower voltage can be compensated by cascading several cells, as it is performed also with Si-solar cells.
Compared to standard materials the inelastic Raman scattering process in NGM will have a high cross section, since excited electrons and holes do not suffer a by resistive phonon interaction decelerated conductivity, but face an unlimited speed to transport energy from the reaction place.
FIG. 9 shows a current/voltage plot of a photo resistor made of NGM having the dimensions of 1 μm×50 nm. Illuminated by light of a gas discharge lamp for white room light the curve 91 was measured. The curve 92 is taken in the dark. It becomes obvious that the voltage is considerable higher in the dark compared with light switched on. A structure of such a photo resistor is known by U.S. Pat. No. 6,246,055.
FIG. 10 shows the principle of a fluorescent lamp, which comprises two plates 102 , 1011 building together with spacers 1013 a low pressure volume filled with noble gas like neon or xenon. Further spacers 103 divide the chamber into cells each of this contains an electron source consisting of an NGM emitter 107 . The spacers 103 carry a grid 105 . A conducting layer 108 on an insulating layer 109 leads a cathode voltage to the field emitter tips 107 . A conducting layer 101 builds anodes and is covered by phosphor spots 100 . Due to the nanogranular material dimensions the voltage required for field emission is strongly reduced due to the high field enhancement factor caused by the small radius of the electron emitting NGM crystal. Field emission for Au/M started at 8 V, instead at 70 V like Mo-Spindt cathodes do.
In operation the voltage Ug of the grid 105 accelerates the electrons emitted by the field emitters 107 in the direction to the anode 101 . But this has a potential of Ua about 2V lower than the cathode potential Uk. Therefore the electrons do not land on layer 101 but oscillate in each cell and excite the noble gas to meta-stable states that radiates UV light hitting the phosphor 100 . The UV light in turn is converted by the phosphor 100 into visible light.
The image display shown in FIG. 11 has a similar structure as the fluorescent lamp shown in FIG. 10 and comprises two plates 1102 building together with insulating spacers 1105 a low pressure (e. g. 1 mbar) volume filled with noble gas like neon or xenon. Electrons oscillating around the grid ( 1104 ) excite the gas to metastable states, which then excite by mechanical collision with the phosphor the light emission. A high positive potential grid 1104 accelerates the electrons emitted by the field emitters 1107 . The field emitters 1107 are separately controllable by provided extractors 1108 . Further on, the cells are adapted to the number of pixels which are to be displayed and the dots of phosphor 1103 emit different colors.
FIG. 12 shows a pair of power switches enabling to switch high voltage at high current, e.g. 3.80 kV and 1000 A. For each half wave on the line 1201 one switch is provided in opposite direction to each other. Both switches comprise arrays of field emitters forming cathodes 1202 . Extractor voltages are supplied to electrodes 1201 . The extractor voltages can be lower than 100 V and can be switched on and off to control the electron current flow between the cathodes 1202 , 1207 and the anodes 1205 . The extractor electrodes 1203 can be arranged in the planes of the field emitters cathodes 1202 . Accelerator dynodes 1204 focus the electrons emitted by the cathodes on the anodes 1205 . As well as the cathode base lines the extractor lines are fabricated as metal lines on an insulating substrate in one lift-off process.
The X-ray image detector shown in FIG. 13 comprises a transparent support 1402 made of SiO2 with tip structures as photo cathodes 1403 made of SiO2 or NIL (nanoimprint lithography) coated with NGM, e.g.by high field deposition to form field emitter tips 1404 which form a two dimensional array. Excited by incident photons 1401 electrons are field-emitted and move through a micro channel plate 1405 , where they multiply the signal, and finally impinge to a charge detector array, from where corresponding signals can be taken.
All elements of the arrangement for manufacturing a conductor shown in FIG. 14 are within a vacuum reaction chamber, which is not depicted. Electrons used for EBID are produced by gas discharge. For this purpose a gas stream supplied at 1301 is controlled by a needle valve 1302 and a pressure meter 1303 . A high voltage supply 1304 builds an electric field which provides a gas discharge 1305 . The electrons of the ionized gas travel through holes in a grid anode 1306 and are accelerated by an adjustable voltage of a grid 1307 in order to define the energy of the elections which travel further towards to a plate 1313 , e. g. of glass. The Gas discharge electron source can also be replaced by a thermal emitter array, a hot or cold field emitter array or corresponding, gas ion sources.
A precursor reservoir 1310 , a valve 1311 , a Peltier heater/cooler, and a nozzle 1309 are designed to supply a beam 1308 of precursor molecules. On the plate 1313 , the temperature of which is controlled by a Peltier heater/cooler 1314 , secondary electrons induced by the electrons produced by gas discharge react with the precursor molecules in the same way as described in connection with FIG. 6 . A tape or wire 1316 moves from a supply reel to a winding reel. Thermal contacts 1315 , 1317 care for a temperature of the tape or wire 1316 , which is about the temperature of the plate 1313 . The substrate temperature can also be adjusted by pre-cooling or pre-heating the substrate in an extra chamber before it enters the vacuum of the deposition chamber. This measure allows additional freedom for process control and precursor deposition before it's conversion by beam energy impact. | Nano granular materials (NGM) are provided that have the extraordinary capability to conduct current in a 100 fold current density compared to high Tc superconductors by charges moving in form of Bosons produced by Bose-Einstein-Condensation (BEC) in overlapping excitonic surface orbital states at room temperature and has a light dependent conductivity. The material is disposed between electrically conductive connections and is a nano-crystalline composite material. Also provided are electrical components comprising NGM and methods and arrangements for making it by corpuscular-beam induced deposition applied to a substrate, using inorganic compounds being adsorbed on the surface of the substrate owing to their vapor pressure, and which render a crystalline conducting phase embedded in an inorganic insolating matrix enclosing the material. | 7 |
FIELD OF THE INVENTION
This invention relates to a posture training device.
REVIEW OF THE PRIOR ART
The importance of correct posture both for health and aesthetic reasons has long been appreciated, and a number of exercises, devices and training aids have been evolved over the years, many of which possess a substantial measure of utility. However, known devices and training aids are usually only effective to correct or prevent a particular postural defect or a limited range of defects.
Thus several devices have been proposed in the form of a belt secured around the waist of a wearer and including some means effective to give a warning signal in response to an increase in tension in the belt beyond a predetermined level. The biological feedback provided by the warning signal helps to train the user not to allow his abdominal muscles to sag. Such devices have been disclosed in U.S. Pat. No. 3,582,935, Australian Pat. No. 291,096 and British Pat. No. 1,036,238. These belts are themselves inelastic except for some limited degree of local extensibility, which is sensed to actuate the warning signal.
Other devices such as those disclosed in U.S. Pat. Nos. 3,268,845; 3,520,294 and 3,820,529, have incorporated belts including elastic transducer elements for the continuous monitoring of chest or abdominal expansion; these devices are intended for quantitatively indicating the magnitude of dynamic expansions or contractions to a medical supervisor without unduly restricting a patient's movements or providing any biological feedback to the patient.
U.S. Pat. No. 3,608,541 describes a device for indicating undesirable excessive curvature of the spine by providing a warning signal. The device is complex in structure and requires the patient to wear a rather restrictive body harness, whilst only signalling those forms of undesirable spinal posture involving excessive lateral curvature.
SUMMARY OF THE INVENTION
A primary object of the present invention is to provide a method and apparatus for posture control which, whilst cheap to manufacture and easy to fit and use, is an effective aid in correcting a substantial range of postural defects.
Broadly speaking, the invention entails monitoring posture by sensing the length of an elastic strap passing from in front and to one side of a person's waist, upwardly over one shoulder, preferably on the same side as said front end of the strap, and downwardly to the rear and the other side of the person's waist. We find that the length of a strap so routed provides a good indication of the distance between the ends of the spinal column, which distance itself is determined both by the straightness of the column and its degree of compression. For reasons of body geometry, the indication is more accurate when the strap is routed over the shoulder on the same side of the wearer as the front end of the strap.
The strap is associated with a warning device so arranged that should the tension in the strap fall below a preset minimum determined by adjusting the free length of the strap, the wearer will be warned, and trained to maintain the ends of his or her spine separated by a distance proportional to the said minimum strap length. An increase in such separation can be achieved by two primary means. Firstly, the amplitude of curves in the spinal column may be reduced, and secondly the compressive forces on spinal column itself may be reduced by muscular action. The beneficial effects of such training are multiple. Excessive curvature of the spine, in any dimension, is reduced or eliminated, and the tone of the muscles used in maintaining correct spinal posture is improved. Improvement in the tone of these muscles automatically acts to decrease abdominal distension and to improve chest expansion. In certain cases at least, regular use of the device will result in an increase in the maximum extension of the spine which can be achieved, and thus to an increase in height. Reduction of spinal curvature improves posture, and decreases the local gravitational stresses placed on its components, whilst the muscle toning referred to above helps reduce the loading on the spine thus still further reducing local stresses. This stress reduction assists in the alleviation of symptoms of existing spinal damage and will help prevent such injury occurring or recurring. The device functions not only to warn the user of defective posture and thus condition him to assume a better posture, but also by reason of its elasticity provides a degree of resistance to the muscular movements required to assume that better posture, thus providing an isometric toning effect.
SHORT DESCRIPTION OF THE DRAWING
A preferred embodiment of the invention is described with reference to the accompanying drawing in which:
FIG. 1 is a diagram showing the device applied to a wearer,
FIG. 2 shows a device in accordance with the invention,
FIG. 3 shows a modified form of the device, and
FIG. 4 is a diagram illustrating the operation of the device.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The posture training device illustrated in FIGS. 1 and 2 of the drawings is a shoulder strap comprising a band of elasticated fabric 2 having a substantial capability for elastic extension beyond its normal unstressed length, a strainable element in the form of a spring 4, connected at one end to one end of the shoulder strap through a shackle 6 and at the other end to an anchorage 8, releasable means 10 and 12 in the form of clips for securing the anchorage 8 and the other end of the shoulder strap to diagonally opposite points on a waistband of clothing worn by the user, and a box 28 connecting the anchorage 8 and the clip 10 and enclosing a buzzer 14, a battery 16 (by means of clips 18 and 20), a switch element 22 which establishes the connection between the spring 4 and the shackle 6, and wires 24 and 26 connecting the switch element 22 and the clip 20 to the buzzer.
By `waistband` we mean either a waistband of items of clothing such as trousers, pants, skirts, dresses or any articles of clothing capable of maintaining a reasonably well defined position relative to the pelvis of the wearer, or a belt having a similarly capability either on its own or when used to support a nether garment. By diagonally opposite points on a waistband we mean points one of which is to the front and one side of the body and the other of which is to the rear and other side of the body, as shown in FIG. 1.
In use, one end of the strap is connected to the waistband at the front and to one side of the waistband, in a similar position to a front strap of a conventional pair of suspenders. The releasable means 10 used for this purpose may be a clip with serrated jaws as shown, or any other suitable fastening means. It is believed however that a clip with spring loaded or suitably clampable jaws, or a fastening comprising a patch of hooked pile fabric such as that sold under the trade mark VELCRO is likely to be the most versatile in permitting attachment of the clips 10 and 12 to different types of waistband W. The band 2 is passed over the shoulder on the same side as the means 10 and the releasable means 12 is attached to the waistband at the rear of the body but on the other side. In the embodiment shown the box 28 is located at the front end of the strap adjacent the clip 10 with a switch actuating lever 30 projecting upwardly. These locations may be varied provided that the clip and switch are readily accessible to the user. The length of the strap is adjusted by means of conventional sliding buckles 32 at either or both ends of the band 2 so that a predetermined degree of upward lift of the user's shoulders relative to his or her waist W, corresponding to minimum degree of spinal extension which is to be maintained, results in a degree of extension of the strap from its unstressed length. This is illustrated in FIG. 4 which illustrates a typically poor posture in full lines, and in broken lines a good posture resulting from extension of the spine as by use of the device of the invention. Such extension in turn entails the presence of a certain minimum tension in the strap which is sufficient to cause extension of the spring 4 so that the switch element 22 is held away from the clip 18. Thus so long as the user's spine is sufficiently extended, a circuit cannot be completed between the battery 16 and the buzzer 14. However, if the switch actuating lever is in the position shown in broken lines, any relaxation of tension in the strap sufficient to permit the spring 4 to contract will result in a circuit being completed between the battery and the buzzer, thus warning the user that the required minimum degree of spinal extension needed to extend the strap is not being maintained. Movement of the switch actuating lever 30 to the position shown in full lines prevents the switch member from contacting the clip 18, thus enabling the device to be fitted or removed and stored without the buzzer sounding. The box 28 of course includes a cover (not shown).
A number of variations are possible in the above design. The buzzer 14 could be replaced by other means providing a sensible stimulus to the user, such as a light, or an induction coil having a secondary winding attached to skin contacting electrodes so as to administer harmless electric shocks to the user. Moreover the buzzer or other warning means could be separate from the remainder of the device and connected thereto by flexible wires or a radio or ultrasonic link. Instead of an electrically operated buzzer, a clockwork operated buzzer or bell could be employed, the electrical switch member being replaced by a mechanical switch member movable into and out of a position in which it blocks operation of a spring driven escapement. The spring 4 and its anchorages could be arranged so that a compression spring could be employed instead of a tension spring, or the switch element itself could be formed by a resilient contact blade, thus eliminating the spring. Indeed, all that is required is a resiliently strainable element which acts to disable the warning means so long as a certain minimum strain is maintained. The resiliently strainable element could be a portion of the elastic strap: for example, in the embodiment shown in FIG. 2, the band 2 could be continued through a clip 32 replacing the shackle 6 and a clip 34, the spring 4 being eliminated. The box 28 may then be situated at an intermediate point on the band 2 instead of at its front end.
The invention could also be embodied in a pair of suspenders, the band 2 being provided by a front strap of the suspenders with the box 28 and its associated parts incorporated therein or attached thereto. In this case, if the straps at the rear of the pair of suspenders were arranged in a Y rather than an X formation, the rear clip or clips would be more or less central: however this arrangement is mechanically equivalent to the X formation in which the rear clips would be attached to the waistband on opposite sides of the body from their front ends.
It is also contemplated that a device incorporating a warning device could be provided for attachment by clips to spaced points on one of the front straps of a pair of suspenders, each of said clips being attached to relatively movable parts of a switch mechanism controlling a warning device so that said switch is operative to activate said warning device when said strap is substantially relaxed and to deactivate said warning device when said strap is extended.
In another variant, the ends of the shoulder strap could be connected to a belt 36 (see FIG. 3) forming part of the device and adapted to be secured around the user in a defined position relative to his or her pelvis, the necessity for relying on a separate waistband.
In any variant of the device, however, two strainable elements are required in the strap: a first element in the form of an elasticated band or a part thereof which is capable of a substantial degree of elastic elongation, and a second element, which may also be part of the elasticated band, which is strained dependent on the tension in the first element and actuates the warning device. The elasticity of the first element is necessary to allow free body movement without disrupting the device and so as to provide the isometric toning effect referred to above.
Adjustability of the free length of the strap is usually necessary so as to accommodate the device to the user, and to adjust the device for progressively increasing degrees of spinal elongation as training proceeds. | A posture training device having adjustable shoulder straps connected to opposite points on a waistband of clothing of a user and including signalling means to apply a sensory stimulus to the user and means to detect the relaxation of tension in the strap. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This patent application is a continuation of my earlier application, Ser. No. 353,250, filed on Mar. 1, 1982, for Drivable, Steerable Platform for Lawnmower and the Like, now U.S. Pat. No. 4,463,821.
BACKGROUND OF THE INVENTION
This invention relates generally to steerable vehicles, and more particularly to a drivable, steerable platform.
Drivable, steerable platforms have been used in industrial and agricultural equipment. Known prior art devices utilize complex mechanical linkages to effectuate steering. The mechanical steering linkages are actuated by hydraulic cylinders driven by a selectively actuated hydraulic pump. The wheels can typically be steered through angles greater than 180°. Due to mechanical limitations of the linkage system, however, the wheels cannot be steered through an angle of 360°.
Typically, such platforms receive their driving power from an internal combustion engine or an electric motor driven by a battery. The engine or motor drives a hydraulic pump which delivers fluid under pressure to hydraulic motors attached to each wheel of the platform. The hydraulic motors that drive the wheels must be carefully regulated for the wheels to each turn at the same speed.
Other known prior art devices include cable steering systems. Such devices include a plurality of spools on which cable is wound and unwound to effectuate steering. In such systems, the wheels of the vehicle cannot be steered through an angle of 360°.
Yet other known prior art devices include wheels powered by an engine through a transmission, pulleys, belts, shafting and gearing assemblies. Sprockets and gear chains may be included to effectuate steering. Hydrauic pumping devices may be used, and the wheels are typically permitted to turn through about 180°.
The control apparatus of known prior art devices permits only limited control of vehicle steering and driving. One known prior art remote control lawnmower can be steered only through relatively large angular turns. Another known prior art lawnmower operates only on the principle of random motion within a boundary.
The known prior art devices offer complex mechanical and/or hydraulic construction and relatively poor control over device steering and driving.
SUMMARY OF THE INVENTION
According to the present invention, a drivable, steerable platform is provided which can be accurately controlled. The platform may be guided in any direction by manual control, remote control, and cassette and computer program control, without a steering wheel. Control structure is provided to permit angular movement in any direction as fine as 0.1°, and straight line movement as fine as a fraction of an inch. The platform has a minimum turning radius of zero.
In one embodiment, a drivable, steerable platform includes a frame member, and 3+N wheel assemblies, N=0, 1, 2, . . . . The frame member is generally disposed in a frame member plane oriented substantially parallel to the surface upon which the platform is to move.
Each wheel assembly includes support structure rotatably connected to the frame member. The support structure is permitted to rotate about an axis substantially perpendicular to the frame member plane.
A wheel member is rotatably mounted on the support structure. The wheel member is permitted to rotate in a wheel rotation plane about an axis substantially parallel to the frame member plane. The wheel rotation planes of the 3+N wheel members are substantially parallel to each other and are all substantially perpendicular to the frame member plane.
Each wheel assembly further includes a first drive structure to drive the wheel member about its axis of rotation. A first steering structure is also provided to rotate the support structure about its axis of rotation. The steering structure permits rotation of the support structure and hence the wheel member through 360°.
A first endless device is provided and connected to each of the first drive structures to rotate each of the 3+N wheel members substantially in synchronism. A second endless device is also provided and connected to each of the first steering structure to rotate each of the 3+N support structures substantially in sychronism.
Structure is provided for selectively driving the first and second endless devices. The drive structure includes a driving device, and first and second clutch structures to selectively connect the driving device to the first and second endless devices, respectively.
According to another aspect of the invention, means are included for activating the drive structure. Relay structures are provided to selectively actuate the first and second clutch structures. A control circuit is provided for selectively operating each of the relay structures.
In accordance with another aspect of the present invention, a receiver is included. The receiver receives broadcasted signals from a remote control point. The received signals are processed to provide control signals for the control circuit. A transmitter may be included for broadcasting signals back to the remote control point.
According to another aspect of the invention, the platform is fixedly connected to a housing structure which accommodates a lawnmower blade. The blade is disposed substantially parallel to the frame member plane, and is driven by the driving device.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will further be described by reference to the accompanying drawings which illustrate the particular embodiments of a drivable, steerable platform in accordance with the present invention, wherein like members bear like reference numerals and wherein:
FIG. 1 is a perspective view of one embodiment of a drivable, steerable platform according to the present invention;
FIG. 2 is a perspective view of the wheel assembly employed in the platform of FIG. 1, and FIG. 2A is a perspective view of an alternate wheel assembly;
FIG. 3 is a perspective view of another embodiment of a drivable, steerable platform according to the present invention, having a lawnmower housing accommodating a lawnmower blade;
FIG. 4 is a planar view of sensor apparatus used in the platform of FIG. 3;
FIG. 5 is a schematic block diagram of control circuitry included on the platform according to the present invention; and
FIG. 6 is a schematic block diagram of control circuitry provided at the remote control point according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, and in particular to FIG. 1, there is shown in perspective view a drivable, steerable platform 10 having a frame member 12 generally disposed in a frame member plane. The platform 10 includes four identical wheel assemblies 14, each of which are illustrated in greater detail in FIG. 2. Each wheel assembly includes a first support structure 16 rotatably connected to the frame member 12. The structure 16 includes a fork 18 fixedly connected to a gear 20. The gear 20 is free to rotate on a shaft 22 which is rotatably mounted on the fram member 12 by a bearing assembly 24. Angular movement of the gear 20 about the axis of shaft 22 produces a similar angular rotation of the fork 18 about the same axis.
Support structure 16 further includes an axle 26 mounted in the fork 18. The axis of axle 26 is disposed substantially parallel to the frame member plane. Wheel member 28 is mounted on the axle 26. The wheel member 28 rotates about the axis of axle 26 in a wheel rotation plane substantially perpendicular to the frame member plane.
A pulley 30 is mounted on the shaft 22, as is a gear member 32. The gear member 32 meshes with a gear portion 34 of the wheel member 28. Rotation of the pulley 30 causes rotation of the gear 32, which in turn drives the gear portion 34, rotating the wheel member 28 about the axis of the axle 26.
In the embodiment illustrated in FIGS. 1, 2 and 3, the pulley 30 is driven by a first endless drive belt 36 disposed on one side of the frame member 12. The gear 20 is driven by a second endless drive belt 38 disposed on the other side of the frame member 12. Alternately, the drive belts 36 and 38 may both be disposed on the same side of the frame member 12.
Preferably, the drive belts 36 and 38 are each geartype endless belts which suitably mate with gear portions included on the pulley 30 and the gear 20. The drive belts 36 and 38, however, may be of any suitable construction, such as "V" belts, chains, and so forth, and the structure of the pulley 30 and the gear 20 altered accordingly.
In the embodiment illustrated in FIG. 3, the endless drive belts 36 and 38 are disposed on opposite sides of the frame member (not illustrated). Six identical wheel assemblies are provided in this embodiment, each wheel assembly being disposed at one of the vertices of a regular hexagon.
A housing 40 is movingly connected to the frame member (not illustrated). A lawnmower blade (not illustrated) is accommodated in the housing 40 and mounted on a shaft 42. A motor or engine (not illustrated) is suitably mounted on the housing 40 and directly connected to end 44 of the shaft 42. The motor causes the shaft 42 to rotate in only one direction as indicated by the arrow in FIG. 3.
A pulley 46 is rotatably mounted on the housing 40 and connected by a belt 50 to the shaft 42. The pulley 46 slidingly accommodates a square shaft 48. The shaft 48 is journalled at one end to the frame member (not illustrated), and is free at the other end to move through the pulley 46.
The pulley 46 and the housing 40 may be moved up and down along the shaft 48 to adjust the height of the lawnmower blade 49. The motor moves up and down with the housing 40 and the pulley 46. The square shaft 48 accommodated by the pulley 46 effectively couples the motor to the platform structure which is to be driven at each lawnmower height setting.
Driving and steering power is provided to the wheel assemblies 14 from the motor through the shaft 48. A belt 52 connects a pulley 54 mounted on the shaft 48 to a driving clutch 56. The clutch is operated by a relay structure (not illustrated). When the relay is operated to actuate the driving clutch, the belt 36 is made to move thereby driving each wheel member 28 substantially in synchronism.
Any slack which may exist in the belt 36 is taken up by belt tension structure 58. The structure includes a spring-loaded tension roller which applies tension to the belt. Impulses tending to be imparted to the belt 36, such as by actuating the driving clutch 56, are absorbed by the spring member of the belt tension structure 58.
A pulley 60, mounted on the shaft 48, is coupled to a steering clutch and brake 62 by a belt 64. The steering clutch and brake 62 is actuated by a second relay structure (not illustrated). When actuated, the clutch mechanism of steering clutch and brake 62 imparts rotative motion from the motor to a shaft 66. The shaft 66 in turn drives the belt 38. When the brake mechanism of the steering clutch and brake 62 is actuated, the shaft 66 is locked in position, thereby locking the belt 36 and gears 20 and forks 18 in position. Belt tension structure 68 is included to take up any slack of belt 38. Belt tension structures 58 and 68 function identically.
In the embodiment illustrated in FIG. 1, the driving clutch 56 and the steering clutch and brake 62 are both mounted on the shaft 42 driven by the motor. In an alternate embodiment (not illustrated), either one or both of the driving clutch 56 and the steering clutch and brake 62 are replaced by d.c. motors. The unnecessary belts, pulleys, and so forth are eliminated.
In other alternate embodiments, the steering clutch and brake 62 is replaced by a suitable electric braking device 63 which operates either on the shaft 66, or the shaft 22 (see FIG. 24) of one or more of the wheel assemblies 14. In operation, when the driving clutch 56 is actuated and the braking device 63 is not, the first support structures 16 of the wheel assemblies 14 rotate about the axis of the shaft 22, thereby effectuating steering. The driving clutch is actuated for a predetermined period of time to steer the first support structures 16 through a predetermined angle. When the braking device 63 is actuated, the first support structures 16 cannot rotate; the wheel members 28 rotate about the axles 26, thereby effectuating driving.
With continued reference to FIG. 3, steering sensor structure and driving sensor structure are included to sense the orientation of the first support structures 16, and the distance travelled by the wheel members 28, respectively. The steering sensor structure includes a steering sensor wheel 70 mounted on the shaft 66, and a steering sensor pickup device 72 mounted in proximity to the steering sensor wheel 70. The sensor wheel 70 and the pickup device 72 are best illustrated in FIG. 4.
The driving sensor structure includes a driving sensor wheel 74 mounted on an axle 76, and a driving sensor pickup device 78 in proximity to the sensor wheel 74. The sensor wheel 74 and the pickup device 78 are similar to those illustrated in FIG. 4.
A steering tension device 80 and a driving tension device 82 are included to adjust the tension of the belts 64 and 52, respectively. The tension devices 80 and 82 are each spring loaded and are similar in construction to belt tension structures 58 and 68, but they provide different functions. They prevent stalling of the motor due to loading of the lawnmower blade and of the wheel members 28.
The driving tension device 82 varies the speed of rotation of the wheel members 28 by permitting slippage of the belt 52 as a function of lawnmower blade loading caused by the grass being cut. Similarly, steering tension device 80 permits slippage of the belt 64 as a function of resistance to steering imparted to the wheel assemblies 14 by the grass. In the illustrated embodiment, the tension devices 80 and 82 are adjusted so that the engine speed, which is normally approximately 3600 rpm, never falls below 2200 rpm. Tension devices 80 and 82 are especially adapted for use with spring clutches which typically actuate in approximately 20 milliseconds.
Structure is also included to readily indicate the direction in which the platform is heading. A belt 84 couples a gear 86 mounted on the shaft 66 with a gear 88 mounted on a shaft 90. So coupled, the shaft 90 rotates in synchronism with the forks 18 of the first support structures 16.
The shaft 90, which is suitably supported in the frame member 12, contains structure for supporting a direction indicating member such as an arrow, a video camera, a seat, and so forth. The direction indicating member is initially oriented to point in the same direction as the first support structures 16. Thereafter, the direction indicating member turns in synchronism with the first support structures 16.
In applications of the present platform to areas other than lawnmowing, for example robot vacuum cleaning devices that are to be oriented in the direction of platform movement, such as a vacuum cleaning tool head or a seat, may be coupled to the shaft 90. So coupled, the device will be seated in synchronism with the first support structures 16 of the platform 10.
Referring now to FIG. 5, control circuitry 100 of the platform 10 is illustrated in block diagram form. A receiver 110 receives a signal broadcasted from a remote control point. The output of the receiver 110 is coupled to a frequency to voltage converter 112 which produces an appropriate electrical signal to drive a line selector 114.
The line selector 114 selectively activates steering command lines A, B, C, D and driving command lines A', B', C', D'. Lines A, B, C, D are conductively connected to a manual angle selector 116 which generates an appropriate steering angle signal. The steering angle signal is coupled to an angle comparator 118 which also receives a steering angle error signal from an electronic compass 120. The steering angle error signal represents the difference between the compass heading the platform 10 should be following, and the one it actually is. Such errors can be brought about by terrain features. Correction for such deviations, however, is effectuated in the illustrated embodiment only when a steering angle signal is produced. The steering angle error signal is added to the steering angle signal in the angle comparator 118 and an appropriate signal fed to a steering counter 122.
The steering counter 122 produces an appropriate signal which is fed to a digital-to-analog converter 124. The converter 124 produces an appropriate signal to actuate the steering clutch and brake 62 previously described.
The steering counter 122 receives an input signal from a steering sensor 126 which includes the steering sensor wheel 70 and the steering sensor pickup device 72 previously described.
Lines A', B', C', D' of the line selector 114 are conductively connected to a manual moving selector 128 which produces an appropriate drive signal. The manual moving selector 128 also receives an input signal from the steering counter 122 which is used to coordinate driving and steering of the platform 10. In the present embodiment, the wheel members 28 are not driven when the forks 18 are being steered to a new orientation. Thus, when the signal received by the moving selector 128 from the steering counter 122 indicates that steering is being effectuated, the drive signal produced by moving selector 128 is not coupled to driving comparator 130. The drive signal is coupled to the driving comparator 130, however, when the signal received by the moving selector 128 from the steering counter 122 indicates that a steering operation is not in progress. It will be apparent to those skilled in the art that if it is desired, the wheel members 28 may be driven when the forks 18 are being steered to a new orientation.
The driving comparator 130 further receives an input signal from a driving counter 132 which in turn receives an input signal from a driving sensor 134. The driving sensor 134 includes the driving sensor wheel 74 and the driving sensor pickup device 78 previously described. The driving counter 132 keeps track of the distance travelled by the wheel members 28.
An output signal from the driving comparator 130 is coupled to a digital-to-analog converter 136. An output of the line selector 114 is coupled to a digital-to-analog converter 138. Output signals from the digital-to-analog converters 136 and 138 are used to selectively operate the driving clutch 56 as previously described.
In the embodiment illustrated in FIG. 5, the direction indicating device includes a video camera 140 which is conductively coupled to a transmitter 142. So coupled, data indicative of the scene viewed by the camera 140 is received by the transmitter 142 for broadcasting to a remote control point. Also received by the transmitter 142 are signals from the steering sensor 126 and the driving sensor 134 containing information regarding the orientation of the platform 10 and the distance travelled by the platform 10, respectively. This information is also transmitted to the remote control point.
Referring now to FIG. 6, control circuitry 150 at the remote control point is illustrated in block diagram form. A receiver 160 receives signals broadcasted by the transmitter 142 of the control circuitry 100. The received signals are processed and fed, in part, to a video display device 162 and, in part, to a computer 164. The data displayed on the video device 162 includes the orientation of the platform 10, the elasped distance travelled by the platform 10, and the present steering angular position or bearing of the platform 10.
The computer 164 further receives input signals from a steering selector 166 and a driving selector 168. The steering and driving selectors 166 and 168 are manually adjustable devices which permit the operator to readily select pre-programmed steering angle commands A, B, C, and pre-programmed driving distance commands A', B', C'. Additionally, the selectors 166 and 168 permit numeric selection of values using the digits 0 through 9. Such selection is represented by steering selector command line D and driving selector command line D'.
The computer 164 receives information from the receiver 160, the steering selector 166, and the driving selector 168. It processes this information in accordance with its programmed instructions and provides control signal information to a transmitter 170 for broadcast to the receiver 110 of control circuitry 100.
As will be apparent to those skilled in the art, the control circuitry 150 at the remote control point can readily be incorporated in the control circuitry 100 on the platform 10. In such an embodiment, the camera 140, the video display device 162, the receivers 110 and 160, the frequency to voltage converter 112, and the transmitters 142 and 170 are not needed. Similarly, numerous features of the embodiment described in FIGS. 5 and 6 can be eliminated without detracting from the present invention. For example, the camera 140 and the video display device 162 can readily be eliminated from the drivable, steerable lawnmower of the present invention.
The principals, preferred embodiments and modes of operation of the present invention have been described in the foregoing specification. The invention is not to be construed as limited to the particular forms disclosed, since these are regarded as illustrative rather than restrictive. Moreover, variations and changes may be made by those skilled in the art without departing from the spirit of the invention. | Control apparatus for an omnidirectional, polar coordinated platform for a lawnmower and the like is disclosed in which a line selector has at least one steering command line coupled to an angle selector, and at least one driving command line coupled to a moving selector. The angle selector produces a steering angle signal which is combined with a compass signal in an angle comparator to produce a steering signal, which is received by a steering counter that selectively activates a steering device. The moving selector produces a drive signal which is received by a driving comparator that selectively activates a driving device. | 1 |
CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation of, and claims priority under 35 U.S.C. §120 to PCT/EP2006/010914, filed on Nov. 14, 2006, and designating the U.S., and claims priority under 35 U.S.C. §119 from European application EP 05024820.2, filed Nov. 14, 2005. These priority applications are hereby incorporated by reference in their entirety.
TECHNICAL FIELD
This invention relates to operating lamp systems and more particularly to operating lamp systems that comprise several operating lamps, each having a controller.
BACKGROUND
Operating lamp systems that comprise several operating lamps, each having a controller, are used in operating rooms and are therefore generally known.
Up to now, it has not been possible to control operating lamps collectively but only separately, see e.g. WO 03/072995 or U.S. Pat. No. 6,402,351.
Operating lamps are often installed as a combination of two or three operating lamps and not as an individual lamp for safety and lighting reasons. The operating parameters of each individual operating lamp are separately adjusted on the housing of each individual lamp.
Modern operating lamps have different operating parameters that can be adjusted. These operating parameters are e.g. the color temperature, the distribution of the emitted light, the brightness and the size of the illumination field or, when an operating lamp with resolved light system or modular construction is used, the overlapping of the individual illumination fields.
SUMMARY
It is an underlying purpose of the invention to further develop a system comprising several operating lamps in such a manner that the operating lamps can be synchronized. This is achieved by a system of the above-mentioned type, wherein data is transferred between the controllers of the individual operating lamps.
In one aspect, the invention features an operating lamp which permits the operating parameters of the other lamps to also be changed by changing the operating parameters of one lamp.
These operating parameters may be separately adjusted for each operating lamp on the operating field of the lamp body, the carrier arms, or the wall operating panel.
In many situations, it may be favorable to simultaneously change the operating parameters of all operating lamps which are in use. When an operating wound is illuminated by two lamp bodies, it may be advantageous that, when the color temperature of one operating lamp changes, the color temperature of the second operating lamp changes synchronously thereto. For this reason, means are provided for synchronizing the operating lamps. This means that the controllers are correspondingly designed to perform automatic communication and mutual matching, if predetermined by the operating surgeon. In a further application, the light intensity may be dimmed. Also in this case, the brightness of two operating lamps which illuminate an operating field can advantageously be synchronously changed. When the illumination is adjusted such that only a very small amount of light is emitted by the operating lamps, which serves as ambient illumination for endoscopic or minimum-invasive operations, the individual lamp bodies are also advantageously commonly switched to this mode, and commonly switched again to an operating mode which permits continuation of the operation with bright light. All lamp bodies can be switched on and off prior to and after operations by means of any operating lamp.
In some cases, it may not be desired to simultaneously change the operating parameters of all installed lamps. When a patient needs to be operated on at different locations, e.g. in bypass operations, where a blood vessel is removed at one location and is inserted at another location, the operating parameters of both lamp bodies must be adjusted independently of each other in order to ensure that the respective operating surgeon has optimum conditions to identify the tissue, i.e. optimum adjustment of the color temperature and illumination of the wound, i.e. brightness and light distribution. In this case, it would not only be disturbing but even dangerous for the patient if the operating lamps were switched off together.
The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features and advantages of the invention will be apparent from the description and drawings, and from the claims.
DESCRIPTION OF DRAWINGS
The FIGURE shows in perspective view three interconnected operating lamps.
DETAILED DESCRIPTION
The schematic drawing shows a preferred embodiment of the invention, which is explained with reference to the drawing.
In accordance with the FIGURE, each individual operating lamp 1 through 3 has several light modules 1 a through 3 a , a pivot arm 1 b through 3 b , and a controller 1 c through 3 c . The light modules 1 a through 3 a are connected to the pivot arms 1 b through 3 b of a support via a carrier, the support being connectable to a ceiling or wall. The light modules 1 a through 3 a are each activated by the corresponding controller 1 c through 3 c . The controller may alternatively also be installed on the corresponding pivot arm or on a wall of the operating room. Each controller 1 c through 3 c has an operating element which permits switching between the individual operating states of the operating lamp 1 through 3 and changing of the parameters also within the operating states:
on/off (complete switch-off or standby state) light intensity (brightness) color temperature illumination situation (selection of the intensity distribution of the emitted light) optional: camera drive (orientation, zoom)
The following parameters are stored in the controller 1 c through 3 c:
Light intensity: e.g. (10%)/50%/60%/70%/80%/90%/100% Color temperature: e.g. 3500 K/4000 K/4500 K/5000 K Illumination situation: e.g. 1 operating surgeon, 2 operating surgeons;
Large-surface wound, deep, narrow wound
When the operating lamp 1 is used in a system of several operating lamps, synchronization of the operating parameters may be selected, i.e. when the color temperature of one operating lamp changes, the color temperature of one or more further operating lamps is/are changed to the same value, which is reasonable when an operating field is illuminated by several operating lamps. In an alternative setting, the operating parameters of the individual operating lamps may be separately changed, which may be reasonable when there are several operating fields.
Switching off and on via the sterile operating element activates or deactivates the standby mode. The operating parameters are stored upon switching off and may be further displayed. When the operating lamp 1 through 3 is switched on, it is in the operating state of the stored, last parameters.
Each operating lamp 1 through 3 is associated with its own controller 1 c through 3 c which can be driven either via an operating field on the lamp body or on the carrier arms, or via an operating panel on the wall. Each of the controllers 1 c through 3 c of all installed operating lamps 1 through 3 has a data interface and communicates with the others via data lines 1 d through 3 d . A central controller 4 is optionally also provided. All controllers 1 c through 3 c of the operating lamps 1 through 3 are programmed in such a manner that, when a certain operating parameter of any lamp body is changed, the controllers 1 c through 3 c of the other operating lamp(s) 1 through 3 recognize the change and synchronously adjust the operating parameters of their respective lamp bodies. One of the operating lamps 1 through 3 can be disconnected from such synchronous operation and be independently adjusted by means of a switch on the lamp body, without changing the operating parameters of the other operating lamp(s). When this operating lamp is readjusted to synchronous operation, it adopts the parameter values of the operating lamps which remained in synchronous operation.
A further function which may be applied for all operating lamps 1 through 3 that are synchronously operated, is resetting of all operating parameters to the switch-on state, i.e., even individual operating lamps 1 through 3 may be reset after disconnecting them from synchronous operation.
A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the following claims. | An operating lamp system is provided that includes several operating lamps, each including a controller. The controllers are interconnected via data lines, wherein data exchange is provided between the controllers. This permits synchronization of the operating lamps. | 7 |
FIELD OF THE INVENTION
This invention relates to a method for stimulating the production of fluids from earthen formations. More particularly, this invention relates to a method in which the productivity of a hydrocarbon-bearing formation is improved upon treatment of the formation with an aqueous solution of a compound later described, said compound effecting the elimination of plugging of capillary openings due to post-precipitation of sparingly soluble salts, effecting elimination of mineral scale on production equipment such as pumps, tubing, etc., caused by such precipitation, and effecting enhanced oil recovery by reduction of retentive forces of capillarity.
DESCRIPTION OF THE PRIOR ART
The technique of increasing the deliverability of a subterranean hydrocarbon-bearing formation by injection of water and thereby stimulating the production of fluids therefrom has long been practiced in the art. The technique is applicable in both limestone and sandstone. In the usual treatment procedure, the aqueous medium is introduced into the well and under sufficient pressure is forced into the adjacent subterranean formation where it dissolves formation components, particularly the carbonates such as calcium carbonate and magnesium carbonate.
During the stimulation process passageways for fluid flow are created or existing passageways therein are enlarged thus stimulating the production of oil, water, brines and various gases. If desired, the stimulation may be carried out at an injection pressure sufficiently great to create fractures in the strata or formation which has the desired advantage of opening up passageways into the formation along which the aqueous medium can travel to more remote areas from the well bore.
There are, however, troublesome complications attending the use of this process. After stimulation is completed, the well is put back on production. The sparingly soluble carbonates, dissolved at the higher reservoir temperatures, may re-precipitate as temperature and hence solubility decrease. Such precipitation, when it occurs within the capillaries of a tight formation or on the tubing or annulus as a mineral scale, can severely lessen production rate by plugging such capillaries or well equipment. In actual practice, the short-lived effectiveness of some stimulations is attributed to salt re-deposition.
In addition, with the exception of increasing the drainage area, and therefore the average permeability by matrix dissolution or hydraulic fracturing, little benefit is obtained. The complete immiscibility of the oil in the water and the retentive forces of capillarity which maintain the oil in the matrix severely limit the production of incremental oil by mere injection of water alone.
It is therefore, the principal object of the present invention to overcome the defects of the prior art in treating fluid-bearing formations such as hydrocarbon-bearing formations, etc., by providing a method of and composition for stimulation employing the novel composition of this invention.
SUMMARY OF THE INVENTION
This invention encompasses and includes a method for increasing the production of fluids from a subterranean fluid-bearing formation comprising injecting down the well bore to said formation and therefrom into said formation under a pressure greater than the formation pressure an aqueous solution of a compound hereinafter more fully described, optionally containing a propping agent therewith, maintaining said aqueous solution in contact with the formation strata for a time sufficient for the compound to chemically interact with the components of the formation.
The novel method of this invention uses an aqueous solution having dissolved therein a compound hereinafter described. The concentration of the compound present in the aqueous solution is such that it is capable of interacting with the soluble components of the fluid-bearing strata so as to prevent reprecipitation of sparingly soluble salts and enhance oil production by reducing retentive forces of capillarity.
BRIEF DESCRIPTION OF THE DRAWING
The FIGURE of the drawing graphically illustrates the thermal stability of the compound of Example IV of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
In its broadest embodiment the method for the present invention comprises introducing into a subsurface formation an aqueous solution of a compound hereinafter described wherein the said solution is maintained in contact with the formation for a time sufficient to chemically interact with the formation so as to increase substantially the oil-producing efficiency of the formation by reducing interfacial tension and hence retentive forces of capillarity. The selection of the correct compound to effect such a reduction in interfacial tension is based upon the formation water salinity, hardness, temperature and other operating variables. This selection may be made basis laboratory displacement tests.
An advantage resulting from the employment of the method of this invention in stimulating fluid-bearing formations is that the post-precipitation of dissolved carbonates is prevented or materially decreased. Such post-precipitation occurs because the salts become less soluble as temperatures decrease. Such a decrease occurs as the fluids approach the production equipment. Such post-precipitation occurring within the formation matrix near the bore hole can decrease permeability by plugging the formation capillaries, particularly those near the well bore, and result in a lower production rate. Furthermore, such post-precipitation can occur in the tubing or annulus of the well itself and manifest itself as mineral scale, reducing their diameter(s) and resulting in a lower production rate.
The compound used in preparing the aqueous solution of the present invention is a water-soluble sulfonated, ethoxylated compound having the general formula:
R(OCH.sub.2 CH.sub.2).sub.n SO.sub.3 .sup.-A.sup.+
wherein R is an aliphatic hydrocarbon group containing from about 8 to about 20 carbon atoms, n is a number from one to about 10 including fractions, and A + is a monovalent cation selected from the group consisting of sodium, potassium, and ammonium, including mixtures.
Representative examples of compounds useful in the practice of the invention include the sulfonated, ethoxylated octyl, decyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, and eicosyl alcohols and also the branched chain isomers thereof. The alcohols can be either a primary or secondary alcohol or a mixture of any of these alcohols.
The ethoxy portion of the alcohol can be, for example, di-, tri-, tetra-, penta-, hexa-, octa-, nona-, and deca.
A particularly preferred group is the C 12 -C 18 primary alcohols containing from about 3 to 10 ethoxy groups therein, and especially the sodium and ammonium salts of these materials.
The concentration of the compound in the aqueous solution can vary from about 0.005% to about 2% by weight, preferably from about 0.05% to about 1% by weight.
In carrying out the method of this invention, an aqueous solution is prepared by mixing the compound with water at the desired concentration. The thus-prepared aqueous solution is forced, usually via a suitable pumping system, down the well bore and into contact with the production equipment and formation to be treated. As those skilled in the art will readily understand, the pressure employed is determined by the nature of the formation, viscosity of the fluid, and other operating variables. The stimulation method of this invention may be carried out at a pressure sufficient merely to penetrate the formation or it may be of sufficient magnitude to overcome the weight of the over-burden and create fractures in the formation. Propping agents, to prop open the fractures as created, for example 20 to 60 mesh sand, in accordance with known fracturing procedures, may be employed in admixture with the aqueous compound. The solution is best kept in contact with the formation and production equipment until the compound can adsorb upon the formation matrix and reduce the interfacial tension. After this, the treating solution is reversed out of the well, i.e., it is allowed to flow back out or to be pumped out of the formation.
In the method of this invention, the compound in the aqueous solution provides means whereby calcium ions having tendencies to precipitate as CaCO 3 or CaSO 4 that is produced by the reaction of the aqueous system with the formation, does not precipitate from the spent treating solution. This binding up of the aforementioned calcium ions from weakly ionizable compouds permits the formed calcium-compound complex to remain dissolved in the treating solution and pass through the formation pores and production equipment.
Further, the compound of the invention provides means whereby the nucleation and growth of the solid itself is thwarted, so that solid calcium carbonate does not precipitate from the spent treating solution.
Further, the compound or the invention provides means whereby continuous protection against post-precipitation of CaCO 3 , or CaSO 4 is obtained for a considerable period of time subsequent to treatment due to continuous slow desorption of the compound from the formation surfaces. In contrast, use of surfactants having merely dispersant and suspending properties and not possessing the capability of molecularly binding up these produced calcium ions or thwarting the nucleation and growth of the solid CaCO 3 will permit deposition of calcium carbonate or calcium sulfate to occur from such treating solution with the likelihood of plugging the formation passageways and production equipment during subsequent recovery of desirable formation hydrocarbons therethrough. Finally, the compound of the invention reduces the retentive forces of capillarity within the formation providing enhanced oil recovery over treatment with water alone.
Following is a description by way of example of the method of the invention.
EXAMPLE I
A producing well in the Lincoln Southwest Field is treated in the following manner.
A treating mixture is prepared by mixing 10,000 gallons of source pond water containing about 200,000 ppm of total dissolved solids with 90 gallons of the sodium salt of sulfonated, pentaethoxylated mixed C 12 -C 18 alcohols. Fifteen thousand pounds of frac sand is added to the aqueous surfactant admixture. The treating mixture is introduced into the formation at a rate of about 7 BPM a 3,000 psig. The shut-in tubing pressure is 2,500 psig. which bled down to zero in a short time. The well is shut in for 13 hours and then returned to production. Estimated production rate increase is from 50 BOPD to 300 BOPD.
EXAMPLES II-IV
The procedure set forth in Example I above is repeated using
Ii -- sulfonated, triethoxylated mixed C 12 -C 18 alcohols containing 40% dodecyl, 30% tetradecyl, 20% hexadecyl, and about 10% octadecyl groups, sodium salt.
Iii -- sulfonated, triethoxylated mixed C 10 -C 14 alcohols containing 80% decyl, 10% dodecyl, and 10% tetradecyl groups, sodium salt.
Iv -- sulfonated, pentaethoxylated mixed C 10 -C 14 alcohols containing 85% decyl, 9% dodecyl, and 6% tetradecyl groups, sodium salt.
It has been found that the compounds used in the method of the present invention are especially effective in the presence of high calcium ion concentrations to 1% by weight or more, and particularly and somewhat uniquely in applications where high aqueous solution temperatures are encountered such as about 100°C. The compounds of the present invention are temperature-stable and effective as scale inhibitors at temperatures up to about 150°C., e.g. 100°-150°C.
The unusual thermal stability of one of the species of the compounds is graphically shown by the accompanying drawing.
In the drawing the graph is constructed on one cycle semi-logarithmic paper having 70 linear divisions along the abscissa.
These data were obtained using the compound of Example IV, above.
At normal operating pHs of 7.5 and 6.3 in deionized water and a representative field water, respectively, half lives at 116°C. (240°F.) are 57.4 and 33 years. The actual experiments were conducted at 400°F., and the half lives extrapolated to 240°F. It is seen that at pH 6.3 in field water at as high a temperature as 204.5°C. (400°F.), a half life of 25 days is attained. At a pH of 1, 23% activity remained after 15 days at 400°F.
In a separate experiment the unusual stability of the compounds is again exhibited by the fact that after exposure of an aqueous solution of the compound of Example I to a temperature of 177°C. for 5 days, 93.5% activity remained.
The disclosed compounds may be prepared in the following manner:
The ethoxylated alcohol is reacted with thionyl chloride for about 18 hours at about 100°C., to form the monochloro derivative, followed by reaction of said monochloro derivative with sodium sulfite for about 18 hours at about 155°C., in a 1/1 by volume admixture of water and ethanol in a Paar Bomb. The resulting recovered sulfonated product, on analysis, showed about 75% sulfonation of the terminal ethoxy group.
This method of preparation is exemplary only, but was the method employed to prepare the tested compositions. Those skilled in the art may perceive other synthetic schemes.
For example, the sulfonated ethoxylated alcohols of the present invention can be prepared from sulfated ethoxylated alcohols by treatment with sodium sulfite at 200°C. for about 10-12 hours, resulting in relatively high yields (75-80%) of the desired sulfonate. The (sulfate) starting material, can be prepared by reaction of an ethoxylated aliphatic alcohol, including mixtures thereof with such reagents as sulfuric acid or chlorosulfonic acid to obtain the sulfated ethoxylated alcohol.
The compounds in Examples I-II above were prepared by reacting a commercially available mixed C 12 -C 18 alcohols (Conoco-Alfol 1218 ) with ethylene oxide to adduct thereto 5 and 3 ethoxy groups respectively. The resulting respective ethoxylated alcohols were then sulfonated as described above. In a similar manner, the compounds of Examples III and IV were prepared using commercially available mixed C 10 -C 14 alcohols, (Conoco Alfols 1014 and 1012).
Obviously, many modifications and variations of the invention as hereinabove set forth may be made without departing from the spirit and scope thereof, and therefore only such limitations should be imposed as are indicated in the appended claims. | The production of hydrocarbons from a subterranean hydrocarbon-bearing formation is stimulated by injecting into the formation an aqueous solution of a compound hereinafter described. The elimination of plugging of capillary openings within the formation and mineral scale deposition on production equipment due to post-precipitation of dissolved salts subsequent to treatment by means of said compound results in a substantial improvement in hydrocarbon recovery. | 4 |
This invention was made with Government support under 70NANB11H004 awarded by the National Institute of Standards and Technology (NIST). The Government has certain rights in the invention.
CROSS REFERENCE TO RELATED APPLICATIONS
The present invention claims priority to U.S. application Ser. No. 13/362,467 entitled “Electrospinning Process for Manufacture of Multi-Layered Structures,” filed Jan. 31, 2012.
FIELD OF THE INVENTION
The present invention generally relates to fiber structures and methods of forming fiber structures using wedge-shaped vessels.
BACKGROUND
Macro-scale structures formed from concentrically-layered nanoscale or microscale fibers (“core-sheath fibers”) are useful in a wide range of applications including drug delivery, tissue engineering, nanoscale sensors, self-healing coatings, and filters. On a commercial scale, the most commonly used techniques for manufacturing core-sheath fibers are extrusion, fiber spinning, melt blowing, and thermal drawing. None of these methods, however, are ideally suited to producing drug-loaded core-sheath fibers, as they all utilize high temperatures which may be incompatible with thermally labile materials such as drugs or polypeptides. Additionally, fiber spinning, extrusion and melt-blowing are most useful in the production of fibers with diameters greater than ten microns.
Core-sheath fibers can be produced by electrospinning, in which an electrostatic force is applied to a polymer solution to form very fine fibers. Conventional electrospinning methods utilize a charged needle to supply a polymer solution, which is then ejected in a continuous stream toward a grounded collector. After removal of solvents by evaporation, a single long polymer fiber is produced. Core-sheath fibers have been produced using emulsion-based electrospinning methods, which exploit surface energy to produce core-sheath fibers, but which are limited by the relatively small number of polymer mixtures that will emulsify, stratify, and electrospin. Core-sheath fibers have also been produced using coaxial electrospinning, in which concentric needles are used to eject different polymer solutions: the innermost needle ejects a solution of the core polymer, while the outer needle ejects a solution of the sheath polymer. This method is particularly useful for fabrication of core-sheath fibers for drug delivery in which the drug-containing layer is confined to the center of the fiber and is surrounded by a drug-free layer. However, both emulsion and coaxial electrospinning methods can have relatively low throughput, and are not ideally suited to large-scale production of core-sheath fibers. To increase throughput, coaxial nozzle arrays have been utilized, but such arrays pose their own challenges, as separate nozzles may require separate pumps, the multiple nozzles may clog, and interactions between nozzles may lead to heterogeneity among the fibers collected. Another means of increasing throughput, which utilizes a spinning drum immersed in a bath of polymer solution, has been developed by the University of Liberec and commercialized by Elmarco, S.R.O. under the mark Nanospider®. The Nanospider® improves throughput relative to other electrospinning methods, but it is not currently possible to manufacture core-sheath fibers using the Nanospider®. There is, accordingly, a need for a mechanically simple, high-throughput means of manufacturing core-sheath fibers.
SUMMARY OF THE INVENTION
The present invention addresses the need described above by providing systems and methods for high-throughput production of core-sheath fibers.
In one aspect the present invention relates to an apparatus used for the electrospinning of core-sheath structures such as fibers. The apparatus comprises first and second wedge-shaped vessels, each having a slit at an apex. The first vessel is disposed inside of the second vessel such that each of the slits of the vessels is aligned. The apparatus includes means for applying a voltage source to one or more materials contained within fluid reservoirs that are in fluid communication with the wedge-shaped vessels. The apparatus also includes means for pumping fluid from one or both of the reservoirs to the wedge-shaped vessels.
Another aspect the present invention relates to a method of forming a structure comprising a core including a first material and a sheath including a second material around said core. The method comprises the steps of providing an apparatus comprising first and second wedge-shaped vessels, each having a slit at an apex thereof where the first vessel is disposed inside of the second vessel such that the first and second slits are aligned. The method further comprises the step of introducing first and second materials, at least one of which is electrically conductive, into the first and second wedge-shaped vessels. The method further comprises the step of applying a voltage of between 1 and 100 kV to at least one of the first and second materials, and pumping the first and second fluids from the fluid reservoirs to the wedge-shaped vessels.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings, like reference characters generally refer to the same parts throughout the different views. Drawings are not necessarily to scale, as emphasis is placed on illustration of the principles of the invention.
FIG. 1 is a schematic illustration of a portion of an electrospinning apparatus according to an embodiment of the invention.
FIG. 2 includes photographs of portion of an electrospinning apparatus according to certain embodiments of the invention.
FIG. 3 includes photographs of electrospinning apparatus of the invention in use.
FIG. 4 is a close up photograph of a Taylor cone from an operating electrospinning apparatus of the invention.
FIG. 5 includes scanning electron micrographs of electrospun core-sheath and homogeneous fibers formed on apparatuses of the invention.
FIG. 6 includes photographs and schematic illustrations of apparatuses utilizing pneumatic fluid supplies according to certain embodiments of the invention.
FIG. 7 includes schematic illustrations and photographs of apparatuses utilizing pneumatic fluid supplies according to certain embodiments of the invention.
FIG. 8 includes schematic illustrations of hydraulically-driven and mechanically-driven fluid supplies according to certain embodiments of the invention.
FIG. 9 includes photographs and schematic illustrations of gravity-driven fluid supplies according to certain embodiments of the invention.
FIG. 10 includes photographs of apparatuses in accordance with the invention having varying geometries (linear and round) and varying slit arrangements (single slits, many holes, few holes).
FIG. 11 includes photographs of diffusers in accordance with the invention.
FIG. 12 includes photographs of even polymer solution flows achieved with a change of the direction of flow in accordance with certain embodiments of the invention.
FIG. 13 includes photographs and schematic drawings of an electrospinning apparatus of the invention having a circular slit.
FIG. 14 includes cumulative dexamethasone release data from core-sheath fibers formed under varying flows of sheath polymer solution.
FIG. 15 includes schematic depictions of apparatuses according to embodiments of the invention.
FIG. 16 includes schematic depictions of apparatuses according to embodiments of the invention.
FIG. 17 includes schematic depictions of apparatuses according to embodiments of the invention.
FIG. 18 includes a schematic depiction of an angle in a wedge-shaped vessel according to certain embodiments of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention relates to electrospun fibers, including drug-containing electrospun fibers, that are produced in a high yield manner. The fibers are formed into a core-sheath configuration, such that in cross section, the fiber includes a central core as an inner radial portion surrounded by a sheath having an outer radial portion, as is known in the art. Fibers of the present invention preferably have a total diameter of no more than about 20 microns.
Examples of biodegradable polymers that can be used with the present invention to form the core and/or sheath portions of a fiber include: polyesters, such as poly(ε-caprolactone), polyglycolic acid, poly(L-lactic acid), poly(DL-lactic acid); copolymers thereof such as poly(lactide-co-ε-caprolactone), poly(glycolide-co-ε-caprolactone), poly(lactide-co-glycolide), copolymers with polyethylene glycol (PEG); branched polyesters, such as poly(glycerol sebacate); polypropylene fumarate); poly(ether esters) such as polydioxanone; poly(ortho esters); polyanhydrides such as poly(sebacic anhydride); polycarbonates such as poly(trimethylcarbonate) and related copolymers; polyhydroxyalkanoates such as 3-hydroxybutyrate, 3-hydroxyvalerate and related copolymers that may or may not be biologically derived; polyphosphazenes; poly(amino acids) such as poly (L-lysine), poly (glutamic acid) and related copolymers. Examples of other dissolvable or resorbable polymers include polyethylene glycol and poly(ethylene glycol-propylene glycol) copolymers that are known as pluronics and reverse pluronics.
Examples of biologically derived restorable polymers that can be used with the present invention include: polypeptides such as collagen, elastin, albumin and gelatin; glycosaminoglycans such as hyaluronic acid, chondroitin sulfate, dermatan sulfate, keratan sulfate, heparan sulfate and heparin; chitosan and chitin; agarose; wheat gluten; polysaccharides such as starch, cellulose, pectin, dextran and dextran sulfate; and modified polysaccharides such as carboxymethylcellulose and cellulose acetate.
Examples of non-biodegradable polymers that can be used with the present invention include: nylon 4, 6; nylon 6; nylon 6,6; nylon 12; polyacrylic acid; polyacrylonitrile; poly(benzimidazole) (PBI); poly(etherimide) (PEI); poly(ethylenimine); poly(ethylene terephthalate); polystyrene; poly(styrene-block-isobutylene-block-styrene); polysulfone; polyurethane; polyurethane urea; polyvinyl alcohol; poly(N-vinylcarbazole); polyvinyl chloride; poly (vinyl pyrrolidone); poly(vinylidene fluoride); poly(tetrafluoroethylene) (PTFE); polysiloxanes; and poly (methyl methacrylate).
Electrospun core-sheath fibers and other structures produced by the systems and methods of the invention may optionally include any suitable drug, compound, adjuvant, etc. and may be used for any indication that may occur to one skilled in the art. In preferred embodiments, the drug or other material chosen is insoluble in the polymers and solvents comprising the core polymer solution, or the concentration of drug or material used exceeds the solubility limit of the drug or material in the polymers or solvents. Without limiting the foregoing, general categories of drugs that are useful include, but are not limited to: opioids; ACE inhibitors; adenohypophoseal hormones; adrenergic neuron blocking agents; adrenocortical steroids; inhibitors of the biosynthesis of adrenocortical steroids; alpha-adrenergic agonists; alpha-adrenergic antagonists; selective alpha-two-adrenergic agonists; androgens; anti-addictive agents; antiandrogens; antiinfectives, such as antibiotics, antimicrobals, and antiviral agents; analgesics and analgesic combinations; anorexics; antihelminthics; antiarthritics; antiasthmatic agents; anticonvulsants; antidepressants; antidiabetic agents; antidiarrheals; antiemetic and prokinetic agents; antiepileptic agents; antiestrogens; antifungal agents; antihistamines; antiinflammatory agents; antimigraine preparations; antimuscarinic agents; antinauseants; antineoplastics; antiparasitic agents; antiparkinsonism drugs; antiplatelet agents; antiprogestins; antipruritics; antipsychotics; antipyretics; antispasmodics; anticholinergics; antithyroid agents; antitussives; azaspirodecanediones; sympathomimetics; xanthine derivatives; cardiovascular preparations, including potassium and calcium channel blockers, alpha blockers, beta blockers, and antiarrhythmics; antihypertensives; diuretics and antidiuretics; vasodilators, including general coronary, peripheral, and cerebral; central nervous system stimulants; vasoconstrictors; hormones, such as estradiol and other steroids, including corticosteroids; hypnotics; immunosuppressives; muscle relaxants; parasympatholytics; psychostimulants; sedatives; tranquilizers; nicotine and acid addition salts thereof; benzodiazepines; barbiturates; benzothiadiazides; beta-adrenergic agonists; beta-adrenergic antagonists; selective beta-one-adrenergic antagonists; selective beta-two-adrenergic antagonists; bile salts; agents affecting volume and composition of body fluids; butyrophenones; agents affecting calcification; catecholamines; cholinergic agonists; cholinesterase reactivators; dermatological agents; diphenylbutylpiperidines; ergot alkaloids; ganglionic blocking agents; hydantoins; agents for control of gastric acidity and treatment of peptic ulcers; hematopoietic agents; histamines; 5-hydroxytryptamine antagonists; drugs for the treatment of hyperlipiproteinemia; laxatives; methylxanthines; monoamine oxidase inhibitors; neuromuscular blocking agents; organic nitrates; pancreatic enzymes; phenothiazines; prostaglandins; retinoids; agents for spasticity and acute muscle spasms; succinimides; thioxanthines; thrombolytic agents; thyroid agents; inhibitors of tubular transport of organic compounds; drugs affecting uterine motility; anti-vasculogenesis and angiogenesis; vitamins; and the like; or a combination thereof.
The invention includes means for co-localizing sheath and core polymer solutions at multiple sites of Taylor cone formation during an electrospinning process so that core-sheath fibers are produced. In certain embodiments, devices of the invention comprise a hollow vessel having a lengthwise slit therethrough, through which a solution of the core polymer can be introduced. Flow of both core and sheath polymer solutions is initiated and an electric field is introduced. These steps are performed in any suitable order: for example, in some embodiments, flow of the core polymer solution is initiated, a field is introduced and Taylor cones and electrospinning jets comprising core polymer solution are formed; then sheath polymer flow is initiated such that the sheath polymer is incorporated into Taylor cones and electrospinning jets. In other embodiments, the sheath polymer flow is initiated first, then the field is introduced and, after formation of Taylor cones and electrospinning jets, the core polymer flow is initiated. In still other embodiments, both polymer solutions are provided simultaneously, then the field is introduced, etc.
Application of an electric field of sufficient strength to apparatuses of the invention leads to formation of Taylor cones and electrospinning jets in the polymer solution or solutions. In some embodiments, Taylor cones and electrospinning jets are formed in the core polymer solution 230 , then the sheath polymer solution 260 is added alongside or above the core polymer solution 230 so that the sheath polymer solution 260 is drawn up into Taylor cones 240 and electrospinning jets 241 . In preferred embodiments, Taylor cones and jets are formed in the sheath polymer solution 260 and the core polymer solution 230 is added, preferably beneath the sheath polymer solution 260 , so that it is incorporated or pulled into electrospinning jets. As illustrated in FIG. 1 , this can be achieved, in preferred embodiments, by using an apparatus 200 comprising nested wedge-shaped vessels 210 , 270 in which an inner vessel 210 is positioned within an outer vessel 270 . A first slit 220 is located at one apex of the inner wedge shaped vessel; 210 , and a second, larger wedge-shaped vessel 270 is arranged so that a second slit 271 is aligned with the first slit 220 and a gap exists between the inner wedge-shaped vessel 210 and the outer wedge-shaped vessel 270 , permitting a solution of sheath polymer solution 260 to flow around the inner wedge shaped vessel 210 . The wedge-shaped vessels 210 , 270 may be oriented so that the slit is aligned with a vertical plumb line, or it may be angled with respect to a vertical plumb line so that extra core polymer solution 230 or extra sheath polymer solution 260 can run-off, preventing formation of inhomogeneities such as globs in the resulting fibers or other structures. The arrangement of the slit 271 of the bath 270 to the slit 220 of the inner vessel 210 is illustrated in FIG. 2 , which shows the slit 271 substantially surrounding the slit 220 . FIG. 3 shows multiple core-sheath Taylor cones 240 and electrospinning jets 241 emanating from the slit 270 when the apparatus is in use. A close-up image of a core-sheath Taylor cone is shown in FIG. 4 . The wedge shaped vessels, in preferred embodiments, include side walls that are angled 30° from the vertical, as shown in FIG. 18 .
The vessels 210 , 270 are made of a conducting material such as stainless steel, copper, bronze, brass, gold, silver, platinum, and other metals and alloys. Slits 220 , 271 preferably have a width sufficient to permit formation of Taylor cones 240 , generally between 0.01 and 20 millimeters, and preferably between 0.1 to 5 millimeters. The length of vessels 210 , 270 is preferably between 5 centimeters and 50 meters, and more preferably between 10 centimeters and 2 meters.
Metals used to form portions of apparatuses of the invention may be polished, brushed, cast, etched (by acid or other chemical or mechanically) or unfinished. The metal finish may be chosen to affect an aspect of the performance of the apparatus; for example, the inventors have found that using polished brass improves the flow of polymer solution. Alternatively, non-metal materials or insulating materials may be used to form all or a part of the components used within the apparatuses of the present invention.
The materials used to form the core and sheath portions of the fibers formed in the present invention are placed into solution before being introduced into the apparatuses that are used for fiber formation. The core polymer solution preferably has a viscosity of between 1 and 100,000 centipoise, and is preferably pumped through the inner vessel 210 at rates of between 0.01 and 1000 milliliters per hour per centimeter, more preferably between 5 and 200 milliliters per hour per centimeter. A voltage, preferably between 1 and 250 kV, more preferably between 20-100 kV, is applied. The positive electrode of the power supply is preferably connected to one or both of the vessels 210 , 270 such that a potential exists between one or both of the vessels and a grounded collector that is placed at a distance. In alternate embodiments the collector is oppositely charged relative to the polymer solution(s). In some embodiments, the collector 250 includes one or more grounded or oppositely charged points (for example, two grounded points separated by a space), and fibers collect around the one or more points and/or between them. Upon application of a sufficient voltage, Taylor cones 240 and electrospinning jets 241 will form at the exposed surface of core and/or sheath polymer solution(s) 230 , 260 and the jets will attract towards the collector.
In preferred embodiments, core and/or sheath polymer solutions 230 , 260 are provided to the interior and exterior, respectively, of the vessel 210 at the slit 220 in a steady, laminar fashion such that fluid velocity and pressure of the core and/or sheath polymers 230 , 260 are constant across the width of the slit 230 over time. Such steady, laminar flow can be achieved by a variety of methods, which may be used alone or combined, and the inventors have found that driving polymer flow pneumatically, hydraulically, mechanically (piston-driven) or by gravity can result in a suitably consistent supply of the required fluids; this aim can also be met by employing flow directing structures such as diffusers in flow paths for the core and sheath polymers 230 , 260 .
With respect to pneumatic driving of fluids, FIG. 6 shows apparatuses of the invention utilizing reservoirs 231 , 261 for core polymer solution 230 and sheath polymer solution 260 , respectively. Each of the reservoirs includes one or more gas inputs 280 , each of which preferably located opposite a conduit 232 , 262 for the core and sheath polymer solutions 230 , 260 , respectively. For example, in the embodiments of FIG. 6 , gas is provided via inputs 280 at the top of the reservoirs 231 , 261 , and polymer solutions exit via conduits 232 , 262 at the bottom of the reservoirs. The conduits of the apparatus 200 preferably have a width that is roughly the same as a width of the slit 220 , thus minimizing the formation of spreading flows and eddies that may result in variances of fluid velocity or pressure across the width of the slit 220 . In some embodiments, turbulent and/or uneven flows are minimized by removing sharp angles or curves from the flow paths from the reservoirs 231 , 261 through the conduits 232 , 262 to the slit 220 ; the flow paths may be, in some embodiments, substantially linear. It will be appreciated that solutions can also be injected through the inputs 280 leading to reservoirs 231 , 261 and 280 to permit continuous electrospinning.
Any suitable gas may be used to drive the flow of core and/or sheath fluids 230 , 260 , including air, but in preferred embodiments a non-reactive or inert gas is used such as nitrogen, helium, argon, krypton, xenon, carbon dioxide, helium, nitrous oxide, oxygen, combinations thereof and the like. The gas used to drive flows is optionally insoluble in the solvents used in the core or sheath polymer solutions 230 , 260 to prevent the formation of gas bubbles during electrospinning. Additional steps may be taken to prevent bubble formation during electrospinning, including de-gassing the core and sheath polymer solutions 230 , 260 prior to use and separating the gas used to drive fluid flows from the polymer solutions 230 , 260 through the use of an impermeable membrane or piston. In some embodiments, an inflatable balloon is used to displace polymer solutions 230 , 260 from the reservoirs 231 , 261 . The reservoirs 231 , 261 and the gas inputs 280 are preferably sufficiently airtight to prevent leakage at the gas pressures used.
As shown in FIG. 7 , pneumatic driving mechanisms may include pressure regulators ( FIG. 7A ) to ensure that gas is provided at a constant pressure, which in turn will advantageously permit the maintenance of even fluid flows during electrospinning. In some embodiments, pneumatic pressure is generated through the use of a piston 285 to compress a fixed volume of gas in an airtight vessel such as a polymer solution reservoir. Finally as shown in FIG. 7C-D , in some embodiments, multiple air inlets 280 are used to ensure pneumatic pressure is applied evenly across the width of the reservoir 231 / 261 and, in turn, that the fluid velocity and pressure is kept even across the width of the slit 220 .
With respect to hydraulic driving of fluids, as shown in FIG. 8 A-B, in preferred embodiments a fluid 281 such as water will be used to displace a piston 285 which then displaces a polymer solution such as the core polymer solution 230 toward the slit 220 . As discussed above, the piston 285 preferably moves through a reservoir or a conduit having a width approximately equal to a width of the slit 220 , and the piston 285 itself preferably has a width substantially equal to the width of the slit 220 . Also as discussed above, an inlet for the fluid 281 and the piston 285 can be disposed within a reservoir opposite a conduit, or in any other suitable arrangement.
In some embodiments, the piston includes one or more sealing features 286 such as gaskets or O-rings to prevent the driving fluid from mingling with the polymer solution. This aim may also be achieved in some embodiments by tailoring the surfaces of the piston 285 and/or the reservoir to repel the fluid 281 used to drive the piston 285 —for example, in embodiments where water is used to drive the piston 285 , the piston and the wall of the reservoir may include hydrophobic surfaces to prevent the migration of water past the piston.
With respect to piston-driven fluids, piston 285 may be made of any suitable material, including plastics, metals and combinations thereof. In some embodiments, the piston 285 is made of a material that is the same as or similar to a material included in the vessel 210 ; in other embodiments, the piston is non-conductive and/or includes a dielectric material. The piston preferably includes a material that is non-reactive with the polymer solutions 230 , 260 . The piston and/or the reservoir may include a coating or surface to render it non-reactive and/or to prevent a gas or liquid used to drive the piston from mingling with the polymer solution. The piston and/or the reservoir may also include a coating to minimize friction between the piston and the walls of the reservoir to prevent binding between the piston to the walls and variation in fluid velocities and pressures delivered to the slit 220 .
Pistons may be driven pneumatically, hydraulically (as discussed above) or by mechanical actuators such as screw actuators or linear actuators. Multiple pistons may be used to drive core polymer solution 230 and sheath polymer solution 260 . As shown in FIG. 8E , in some embodiments, sheath polymer solution is driven by multiple pistons 285 A which are coupled to one-another to ensure the supply of sheath polymer solution is consistent on either side of the slit 220 .
Pressure diffusers can be used to even out flow across a vessel and/or a slit for electrospinning Pressure diffusers, as the term is used herein, refers to structures that obstruct at least a portion of a flow path to re-direct a relatively narrow stream of fluid over a larger area. A pressure diffuser may include holes, slits, or other apertures to permit fluid to flow through the diffuser. A diffuser may also include angled, curved, or beveled surfaces to force fluid contacting such surfaces to flow in desired directions around the diffuser. One or more diffusers can be arranged, in parallel or in series, across a flow path to more fully diffuse the flow of a solution. The diffuser can include surfaces parallel to, perpendicular to, or otherwise angled to a desired direction of flow. A selection of diffusers compatible with the invention are illustrated in FIG. 11 .
With respect to gravity-driven fluid flows, in such embodiments, a reservoir such as a core polymer solution reservoir 231 will be positioned above the hollow vessel 210 and the slit 220 , such that the polymer solution 230 / 260 will flow downward by gravity from the reservoir toward the slit. The apparatus 200 includes a vent or valve through which air can enter the reservoir 231 / 261 to occupy space vacated by polymer solution 230 / 260 as it flows toward the slit 220 .
In some embodiments, the polymers used in the present invention include additives such as drug particles, metallic or ceramic particles to yield fibers having a composite structure.
Other suitable vessel geometries may be used in accordance with the present invention, including round designs as shown in FIG. 13 and as described in Example 8. The methods and apparatuses described above can be adapted and/or combined to form core-sheath fibers using a round vessel having a round slit. Core polymers and sheath polymers can be provided to the slit in a round vessel using nested annular flow paths, as is illustrated in FIG. 13E ; these annular flow paths are compatible with piston-driven, hydraulically-driven, or pneumatically driven polymer systems described above.
In addition, although the disclosure focuses on systems and methods utilizing a single lengthwise slit, any suitable aperture geometry may be used, including without limitation multiple short slits, holes, curved slits, slits and holes together, etc. Similarly, the invention includes systems and methods utilizing complex three-dimensional arrangements, such as that shown in FIG. 15 , utilizing multiple disks 350 , each disk containing three troughs in a manner similar to that shown in FIG. 5 - a central trough 310 for the core polymer solution 220 flanked by troughs 320 , 330 for the sheath polymer solution 260 . In the system of FIG. 15 , the core and sheath polymer solutions are supplied by a central line 360 connected to each disk. Upon application of an electrical field, Taylor cone formation and formation of electrospinning jets occurs in a radially outward direction, and the resulting fibers are collected on a grounded collector 370 disposed circumferentially about and at a suitable distance from the disks 350 .
Preferred embodiments of the invention utilize elongate areas including slits for electrospinning. Using elongate areas rather than, say, radially symmetrical or square areas advantageously permits multiple solutions or materials to be continuously and evenly supplied to sites of Taylor cone and electrospinning jet formation such that they are closely apposed, yet remain separate. In non-elongate areas such as squares, Taylor cones and electrospinning jets that form in the center of the area tend to deplete the supply of materials or polymer solutions in the center of the area, which materials cannot be replaced as efficiently and evenly while remaining in an unmixed fashion as is possible in narrower, more elongate areas. In addition, the use of elongate areas provides a straightforward path to scaling-up fiber production: as the long dimension of the elongate area increases, it is possible to form more Taylor cones and electrospinning jets within the area, yet by keeping a short dimension relatively constant, materials and polymer solution can be rapidly supplied from alongside or underneath the area to prevent depletion. Suitable dimensions for slits in apparatuses of the invention are disclosed in Examples 7 and 8, below.
The systems and methods described herein can be adapted to form structures other than core-sheath fibers. For example, core-sheath particles may be formed using core and/or sheath polymer solutions with low viscosity. Upon introduction on an electric field, Taylor cones and structures similar to electrospinning jets (which are referred to as “spray jets” herein) will form. Due to the low viscosity of the solutions, the spray jets will break-up midstream leading to particle formation. Optionally, vibration can be used to disrupt the flow of the core and/or sheath solutions to further encourage the formation of spray jets and/or particles.
The invention also includes combinations of the systems and methods described above. For example, structures incorporating multiple sheath polymers can be formed using a vessel/bath setup as described above in combination with a syringe pump to provide a second sheath polymer solution to sites of Taylor cone formation.
In some embodiments, one or more of the core polymer solution and the sheath polymer solution is delivered in a pulsatile manner to create fibers with gradients of core densities and/or sheath thicknesses.
The invention includes systems and methods in which limited or no structure is used to separate core and sheath polymer solutions 220 , 260 . As shown in FIG. 16C , multiple polymer solutions may mix poorly such that little or no structural separation between core and sheath polymer solutions 220 , 260 is necessary to form structures with distinct cores and sheaths. In the embodiment depicted in FIGS. 16A-B , core polymer solution 220 is provided at discrete points within an electrospinning vessel; the remainder of the vessel is filled with sheath polymer solution, and a field is then applied to initiate electrospinning.
The devices and methods of the present invention may be further understood according to the following non-limiting examples:
Example 1
Electrospinning Conditions for Various Slit/Hole Geometries
Slit-surfaces of various geometries were fabricated and the formation of electrospinning jets from these surfaces was demonstrated. FIG. 10 shows slit-surfaces that are (A) continuously linear, (B) continuously circular, (C) continuously linear with holes, and (D) non-continuous holes. The respective dimensions of slits or holes and the electrospinning conditions used therefore are presented in Table 1, below:
TABLE 1
GEOMETRIES AND ELECTROSPINNING CONDITIONS
FOR APPARATUSES SHOWN IN FIG. 10:
Slit
Apparatus
Polymer
Slit
Electric
Geometry
Geometry
solution
dimensions
Flow rate
Flow Source
field
Continuously
Wedge
6 wt % PLGA
0.5 mm ×
60 ml/hr
Underneath
40 kV
linear
75/25 in TFE
35 mm
Continuously
Annular or
2 wt % PLGA
1 mm ×
120 ml/hr
Underneath
40 kV
circular
Showerhead
85/15 in
80 mm
Chloroform/
Methanol(6:1)
Continuously
Tube
2.5 wt % PLGA
8 cm long
30 ml/hr
Ends
40 kV
linear with
85/15 in
holes
Chloroform/
Methanol(6:1)
Non-
Tube
2.5 wt % PLGA
5 cm long
20 ml/hr
Ends
40 kV
continuous
85/15 in
holes
Chloroform/
Methanol(6:1)
Example 2
Achieving Even Flow of Polymer Solutions Using Mechanical Piston
Even flow of polymer solution to a slit was achieved by the use of a mechanical piston. FIG. 17A-B depicts the apparatus used. The wedge-shaped slit fixture is attached to a chamber connected to a piston that is mechanically driven using a syringe pump. As the piston moves forward, it pushes solution uniformly towards the slit. Using a flow rate of 50 ml/h and a voltage of 50 kV, multiple electrospinning jets emerged along the entire length of the slit as shown in 25 C.
Example 3
Achieving Even Flow of Polymer Solutions Using Pressure Diffusers
Even flow of polymer solution to the slit was achieved by incorporating pressure diffusers to divert momentum of fluid flow across the slit. Shown in FIG. 11 are examples of such diffusers. In FIG. 11A , the diffuser is a triangular fixture that contains holes across its length to allow polymer solution to flow through. To demonstrate its ability to divert fluid flow, the diffuser was press-fit inside a container such that flow of solution is forced through its holes rather than around. As shown in FIG. 11B , a dyed solution of PLGA in chloroform:methanol that was pumped into the container from one inlet source encounters the diffuser, spreads across the length of the chamber, and then flows through the holes of the diffuser. The result is a more even distribution of fluid flow across the length of the chamber. Similarly, FIG. 11C shows a circular shaped pressure diffuser that contains holes across its surface. As shown in FIG. 11D series of these diffusers were press fit into a tube and filled with non-dyed polymer solution of PLGA in chloroform:methanol. A dyed solution of the same solution was then pumped into the tube from one inlet source at the bottom. Similar as before, the solution encounters the diffusers, spreads across the area of the tube, and then passes through the holes of the diffuse. The result is a more even distribution of fluid flow across the tube. Pressure diffusers can be incorporated into the apparatus of the invention to achieve even flow of polymer to the slit surface.
Example 4
Achieving Even Flow of Polymer Solutions Using Polymer Solution Re-Direction
Another method for even flow can be achieved by redirecting polymer solution to flow in the opposite direction of initial direction. Shown in FIG. 20 is an experiment in which a 2 wt % PEO solution in 60:40 (by vol) ethanol:water is pumped through a tube that faces down inside a container. The tube is placed 10 mm away from the bottom of the container and fluid flow is set at 50 ml/h. The solution contains a blue dye to visualize the fluid flow pattern. As demonstrated, solution initially travels in the downward direction and upon encountering the wall of the container, proceeds to spread across the bottom and rise up uniformly. This diversion of momentum of fluid flow concept can be incorporated into the apparatus of the invention to achieve even flow of polymer to the slit surface.
Example 5
Electrospinning of Core-Sheath Fibers Using Direct Feed of Polymer Solutions
Core-sheath fibers were manufactured using an apparatus according to the embodiment of FIGS. 1 and 2 . The apparatus consists of an inner trough with a slit width of 0.5 mm, while the width of the outer trough is 2 mm. The length of the entire slit is 7 cm. These wedge-shaped slits were affixed to a base fixture that allowed polymer solution to be directly delivered from inlet ports originating from the underside of the fixture.
A sheath solution 260 of 2.8 wt % 85/15 PLGA in 6:1 (by vol) chloroform/methanol and a core solution 230 of 2.8 wt % 85/15 PLGA in 6:1 (by vol) chloroform/methanol containing 30% wt % dexamethasone drug with respect to PLGA was used. The sheath flow rate was set at 100 ml/h while the core flow rate was set at 50 ml/h. A voltage of 50 kV was applied.
Example 6
Electrospinning of Core-Sheath Fibers Using Pneumatic Feed of Polymer Solutions
Core-sheath fibers were manufactured using an apparatus according to the embodiment of FIGS. 1-2 and 6 . The apparatus consists of an inner trough capable of holding 50 mls of polymer solution and outer troughs capable of holding 100 mls of sheath polymer solution. The slit width of the inner trough is 0.5 mm, while the width of the outer trough is 2 mm. The length of the slit is 3.5 cm. Polymer solution was delivered to the respective slits via pneumatic actuation using a syringe pump and empty syringe. A sheath solution of 6 wt % PLGA in hexafluoroisopropanol (HFIP) was delivered at 60 mL/min and a core solution 230 of 15 wt % PCL in 6:1 (by vol) chloroform/methanol containing 30% wt % dexamethasone drug with respect to PCL was delivered at a rate of 10 mL/min. A voltage of 50-60 kV was applied and numerous core-sheath jets were emitted from the slit-surface of the apparatus and fibers were collected. FIG. 3 shows multiple core-sheath Taylor cones 240 and electrospinning jets 241 emanating from the slit 270 when the apparatus is in use. The core-sheath structure of the resulting fibers was confirmed by scanning electron microscopy, as shown in FIGS. 5A-D , which includes multiple scanning electron micrographs of fibers 100 having distinct cores 120 comprising dexamethasone particles and sheaths 130 . FIG. 5E shows a control fiber made from a single PLGA/PCL/dexamethasone blend which does not exhibit the core-sheath structure.
Example 7
Electrospinning of Core-Sheath Fibers Using Pneumatic Feed of Polymer Solutions
Fibers with various core-sheath structures were fabricated using an apparatus according to the embodiment of FIGS. 1-2 and 6 . Core-sheath structure was varied by varying the outer sheath flow rate while keeping the core flow rate constant. The sheath solution 260 consisted of 6 wt % PLGA in hexafluoroisopropanol (HFIP) while the core solution 230 consisted of 15 wt % PCL in 6:1 (by vol) chloroform/methanol containing 30% wt % dexamethasone drug with respect to PCL. The core flow rate was kept constant at 20 ml/h while the sheath flow rate was adjusted to either 40 or 100 ml/h. A control fiber made from a PLGA/PCL/dexamethasone blend was also fabricated. To evaluate the different core-sheath structures, elution of the dexamethasone drug from fibers was evaluated. Varying the sheath flow rate had the effect of varying the release kinetics of dexamethasone. Without wishing to be bound to any theory, the inventors hypothesize that greater sheath flow rates led to thicker sheaths, which restricted diffusion of drug from fiber cores more completely than in fibers formed in conditions of lower sheath flow.
Example 8
Electrospinning from Circular Fixture
An apparatus incorporating a round slit rather than a linear one has been used. A showerhead fixture was modified, replacing a center piece with a plug to form a circumferential slit. When a 1 wt % PLGA solution was provided to the slit, multiple Taylor cones and electrospinning jets were observed, as shown in FIGS. 13 A and D.
The term “and/or” is used throughout this application to mean a non-exclusive disjunction. For the sake of clarity, the term A and/or B encompasses the alternatives of A alone, B alone, and A and B together. The aspects and embodiments of the invention disclosed above are not mutually exclusive, unless specified otherwise, and can be combined in any way that one skilled in the art might find useful or necessary.
The term “elongate” is used throughout this application to refer to structures having at least two dimensions, one dimension being longer, and preferably substantially longer, than the other(s). For the sake of clarity, the term “elongate” encompasses structures that are linear, cylindrical, cuboidal, curved, curvilinear, toroidal, annular, angled, rectangular, etc. and any structure that could be formed by bending or curving one of the elongate structures listed above.
While several embodiments of the present invention have been described and illustrated herein, those of ordinary skill in the art will readily envision a variety of other means and/or structures for performing the functions and/or obtaining the results and/or one or more of the advantages described herein, and each of such variations and/or modifications is deemed to be within the scope of the present invention. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and/or configurations will depend upon the specific application or applications for which the teachings of the present invention is/are used. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. It is, therefore, to be understood that the foregoing embodiments are presented by way of example only and that, within the scope of the appended claims and equivalents thereto, the invention may be practiced otherwise than as specifically described and claimed. The present invention is directed to each individual feature, system, article, material, kit, and/or method described herein. In addition, any combination of two or more such features, systems, articles, materials, kits, and/or methods, if such features, systems, articles, materials, kits, and/or methods are not mutually inconsistent, is included within the scope of the present invention.
The breadth and scope of the invention is intended to cover all modifications and variations that come within the scope of the following claims and their equivalents: | Devices and methods for high-throughput manufacture of concentrically layered nanoscale and microscale fibers by electrospinning are disclosed. The devices include a hollow tube having a lengthwise slit through which a core material can flow, and can be configured to permit introduction of sheath material at multiple sites of Taylor cone formation formation. | 3 |
BACKGROUND OF INVENTION
The invention relates to an apparatus for grinding semifinished steel products, particularly but not exclusively in the form of billets, requiring material removal up to the depth of penetration of cracks near the surfaces. The apparatus includes a grinding wheel which is movable in respect of its height position relative to the semifinished product and has its axis arranged substantially parallel with the longitudinal axis of the product whilst the semifinished product is simultanenously advanced in the direction of its longitudinal axis and rotated about the latter. A stop member in the shape of a segment having approximately the same curvature as the grinding wheel relative to the grinding wheel axis controls the position of the grinding wheel relative to the surface of the semifinished product so that material is removed uniformity around the entire periphery of the semifinished product. The stop member is vertically adjustable and rests on the unabraded surface of the semifinished product at a position which is spaced beneath the point of engagement of the grinding wheel by a distance which corresponds to the penetration depth of the grinding wheel.
Such an apparatus is known from U.S. Pat. No. 2,347,639. In that case an arcuate stop member in the form of a slipper is vertically adjustable by means of a screwspindle on an arm which is secured to a support. The support engages operatively with a lever which carries the bearing of the grinding wheel. In practice a multi-link mounting assembly of this type not only leads to a very expensive construction but also to substantial transmission faults due to dimensional deviations of the individual links from their respective designed measurements and their progressive wear which is very considerable under the rough operative conditions involved in the grinding of semifinished steel products.
A similar device for grinding semifinished steel products is also known from U.S. Pat. No. 2,558,943. Here switch levers are provided on both sides of continuously advancing steel billets to be ground. These levers are encountered by the billet edges on turning and trigger the switches of switching circuits which by means of further switches for which a cam controlled by sensor fingers resting on the faces of the billets and associated with an actuating device is provided which controls the supply of compressed air to pneumatic cylinders. The latter have one part thereof mounted on the machine frame whilst their respective other parts are applied to a bearing arm of the grinding wheel and thus allows grinding pressure to be modified in relation with the given rotational position of the billet. This grinding pressure control is so arranged that in the vicinity of the edges the application pressure is reduced so that corresponding to the longer dwelling time in this region some equalisation is obtained. However, in so far as the preselected relation of grinding pressure to angular position does not correspond to the actual functional conditions, the intended equalisation is only partly achieved. In particular, the specific grinding pressure depends very largely on the material composition. Added to this it must be remembered that even if all the other material influences are known, local strength variations in the semifinished products cannot be detected and that these may well be the cause for inadequate equalisation of material abrasion.
It is further known, according to French Pat. No. 66 400, in the grinding of billets to reduce the edge pressure of the grinding wheel by means of an hydraulic control system which in turn is subject to the influence of an hydraulic adjusting member which is charged by a roller sitting on a template which revolves with the billet. The actual billet measurements however are not detected in this case. Moreover, the grinding-pressure control is subject to the above described influential factors.
BRIEF SUMMARY OF THE INVENTION
It is an object of this invention to provide a semifinished steel product which has a reliable and simple construction and which has fewer transmission faults than the prior art arrangements.
According to one aspect of this invention there is provided an apparatus for grinding a semifinished steel product which requires removal of material up to the penetration depth of cracks near the surface thereof and which is advanced in the direction of the longitudinal axis thereof whilst being rotated about said longitudinal axis, said apparatus comprising a support member movably mounted on the apparatus, a bearing provided in said support member, a grinding wheel mounted in said bearing with its axis parallel to the longitudinal axis of the semifinished product and arranged so that its axis is movable relative to the semifinished product, a stop member in the form of a segment of a circle pivotally mounted on the support member so that the segment is eccentric relative to the axis of the grinding wheel, and means for pivotally adjusting and locking the stop member in position, said stop member resting on the unabraded surface of the semifinished product at a position which is spaced from the point of engagment of the grinding by a distance which corresponds to the penetration depth of the grinding wheel and said stop member controlling the position of the grinding wheel relative to the surface of the semifinished product so that material is removed uniformly around the entire periphery of the semifinished product.
According to another aspect of this invention there is provided an apparatus for grinding a semifinished steel product which requires removal of material up to the penetration depth of cracks near the surface thereof and which is advanced in the direction of the longitudinal axis thereof whilst being rotated about said longitudinal axis, said apparatus comprising a support member movably mounted on the apparatus, a bearing providing in said support member, a grinding wheel mounted in said bearing with its axis parallel to the longitudinal axis of the semifinished product and arranged so that its axis is movable relative to the semifinished product, a stop member in the form of a segment of a spiral pivotally mounted on the support member coaxially with the axis of the grinding wheel, and means for pivotally adjusting and locking the stop member in position, said stop member resting on the unabraded surface of the semifinished product at a position which is spaced from the point of engagement of the grinding wheel by a distance which corresponds to the penetration depth of the grinding wheel and said stop member controlling the position of the grinding wheel relative to the surface of the semifinished product so that material is removed uniformly around the entire periphery of the semifinished product.
One basic feature of the invention resides in that the stop member is adjusted not by means of a vertical longitudinal sliding displacement thereof, but by virtue of pivotal movement. The pivotal bearing of the stop member is mounted on the support member in the immediate vicinity of the grinding wheel axis or even coaxial therewith. The position of the segment which forms the stop member is in such a construction transmitted directly, or with minimum play, to the bearing of the grinding wheel so that the grinding wheel wall with high precision execute that degree of material removal which has been predetermined by the setting of the segment. The correct penetration depth is also achieved by varying the material strength or its hardness values by making variations in its composition or heat treatment. For grinding steel billets the segment can be so closely set that the point of contact of the grinding wheel is spaced from the point of contact of the stop member by approximately 1 mm.
The longitudinal feed movement of the semifinished product on the one hand, and its rotation about the longitudinal axis on the other, result in a slightly spiral grinding trace in which the grinding pass widths overlap. The pitch of this spiral trace, whilst not being very strongly marked, is sufficient to be obliquely directed relative to the cutting line in the case of a right angle cut as is very frequently required for semifinished products. For this reason it is not possible for any damage such as grinding cracks or the like to issue from the grinding traces in respect of sections cut off the semifinished product vertically relative to its longitudinal axis.
The execution of the stop member in the form of a segment of a circle is technologically particularly easy. On the other hand, a stop member in the form of a spiral segment has the advantage of being capable of coping also with larger variations in height position.
Wear on the segment itself can be reduced by providing the end stop with a roller follower which rests in contact on top of the product.
The adjusting and locking means may be realized in various ways. In particular, it is of advantage if the adjusting and locking means is amenable to automation such that the stop member can be adjusted for a given degree of grinding abrasion for each meter length of billet.
In the simplest form, the adjusting and locking means comprises a holder having an internal screw thread mounted on said support member and a screw threaded spindle threadly mounted in said holder and engaging said stop member. The spindle may be adjusted, when required, in a desired manner.
Alternatively, the adjusting and locking means may comprise a piston-cylinder unit, one part of said unit being mounted on the support member and the other part operatively engaging the stop member.
Normally, the grinding wheel has a cylindrical work face. Since abrasion must be effected in a plane, it is necessary that the longitudinal axis of the semifinished product and the grinding wheel axis are parallel to each other. However, under unfavorable conditions, that is to say if the support member which carries the grinding wheel bearing is sufficiently firmly mounted, the points of support of the grinding wheel and the points of support of the stop member may cause a slight amount of angular inclination of the grinding wheel axis.
This problem may be avoided by providing a second stop member mounted on the support member adjacent the side of the grinding wheel which faces the abraded surface of the semifinished product, said second stop member resting on the abraded surface of the semifinished product at a distance from the axis of the grinding wheel which is the same as the distance between the point of engagement of the grinding wheel and the axis of the grinding wheel.
The apparatus may also include means for detecting the rotational positions of the semifinished product. Such means may be functionally influenced directly by the configuration of the stop member. For example, the rotational position detecting means may comprise a position indicator mounted on the support member and an adjustable contactor coacting with the position indicator. Desirably, the position indicator reaches the contactor when the height position of the segment has been lifted by more than two percent from its lowest position. A lift of more than two percent corresponds to a billet rotating through approximately 20° with the grinding wheel engaging the billet between its corners. The position indicator will fall again to the level of the contactor after the billet has rotated through about 70° and the grinding wheel has passed over a corner of the billet.
Alternatively, the rotational position detecting means may comprise a cruciform shaped switch operating member which rotates together with the semifinished product, and a switch operated by said switching member, said operating member closing said switch each time the semifinished product has rotated through 90° and maintaining the switch in a closed state for rotation through an angle less than 90°.
Preferably where the product has an approximately square cross-section, said apparatus includes means for rotating the semifinished product, said rotating means being responsive to the rotational position detecting means, and, during each rotation of 90°, said rotating means rotates the product approximately three times as fast during rotation through each angle of approximately 35° with the grinding wheel adjacent to a corner of the product than during rotation through an angle of approximately 20° with the grinding wheel between the corners of the product.
Alternatively, the apparatus may include means for varying the speed of rotation of the semifinished product, said means comprising a drive motor, a transmission gear member rigidly mounted on the semifinished product, and an elliptical gear transmission train having an input gear member driven by the motor and an output gear member driving said transmission gear member, the circumference of the transmission gear member being four times greater than that of the output gear member, whereby the product is driven faster when the grinding wheel engages portions adjacent to its corners than when the grinding wheel engages portions between its corners.
Where the product has a substantially square cross-section, the position of the stop member may be adjusted in accordance with the rotation of the product subject to the condition that the grinding wheel is lifted in the region of the corners of the product.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric view of an apparatus embodying this invention;
FIG. 2 is a schematic front view of a grinding wheel forming part of the apparatus of FIG. 1;
FIG. 3 shows a modification to the adjustment device for a stop member forming part of the apparatus of FIG. 1;
FIG. 4 shows a modification to the stop member;
FIG. 5 is a block diagram of an arrangement for varying the rotational speed of the semifinished product in accordance with its rotational positions; and
FIG. 6 shows an alternative arrangement for varying the rotational speed of the product.
DETAILED DESCRIPTION
Referring now to the drawings, there is shown an apparatus which includes a grinding wheel 2. The axis 1 of the grinding wheel 2 is mounted in a bearing 10 provided in an elongated support member 3 which consists of two mutually parallel arms. In addition to this, driving means for the grinding wheel are provided. This means comprises a belt pulley, not shown, over which passes a drive transmitting belt which transmits drive from a motor mounted at the other end of the support member 3.
The grinding wheel 2 rotates about an axis 5 which extends parallel with the longitudinal axis 16 of a billet 14 which is to be machined. The billet 14 is advanced in the feed direction as well as being rotated during this movement about its longitudinal axis 16 in the direction of arrow 17. As a result of these provisions the grinding wheel 2 is abrasively applied to the surface 4 of the billet 14 with a sufficient depth of penetration 6 into the billet surface 4 to remove cracks which originate from the surface 4.
A stop member which comprises a segment of a spiral is mounted on the grinding wheel bearing 10 on the side of the as yet unabraded billet surface 4 and therefore pivotally coaxially with the grinding wheel axis 5. In order to achieve adjustment and locking, the segment 9 is engaged by a screw threaded spindle 18 which cooperates with a holder 12 mounted on the support member 3. By rotation of the spindle 12, the segment 9 can be variably adjusted and locked in position in such a way as to ensure that the predetermined height difference of the contact point 7 of the segment 9 relative to the contact point of grinding wheel 2 is maintained.
For improved stabilisation of the grinding wheel axis 5, as mentioned earlier on, a further stop member 19 is arranged on the opposite side to stop member 9 with its point of contact 13 with the already abraded billet surface 11 at the same level as the grinding wheel 2. This provides on both sides of the grinding wheel bearing 10 an identically high support for the two-armed support member 3 by means of stop members 9 and 19 relative to the billet surfaces 4 and 11 respectively.
The stop member 19 shown in FIG. 2 also affords continued support for grindng wheel 2 in one end position of the billet 14 when the feed of the billet 14 is almost fully advanced and the stop member 9 no longer engages the billet 14.
Furthermore, the height adjusting mechanism for the stop member 9 can be controlled advantageously in such a way that in relation with the rotation angle of the billet there will be produced a variation in spacing in consequence of which the grinding wheel 2 will be lifted in the corner regions of the billet.
According to FIG. 3, the adjustment of the segment 9 is obtained with the aid of a piston-cylinder unit having a piston rod 19' and a cylinder 20. The position rod 19' engages operatively with the segment 9 whilst the cylinder 20 is hinged to the support member 3 which carries the grinding wheel bearing 10. The cylinder 20 is connected to an hydraulic unit.
In the embodiment according to FIG. 4, the segment 9 is equipped with a roller follower 21. In this case, the circular edge of the segment 9 has a somewhat smaller radius. The segment has, as indicated in the drawing, an undercut groove track 29 in which is guided a threaded nut, not discernible in the drawing, so that a bearing bolt 30 on which the roller 21 is mounted, can be screwed down and made fast. The roller 21 will in each case be fixed in a position suitable for a limited range of height adjustment for segment 9.
As hereinbefore proposed, the segment 9 may be a segment of a circle or a segment of a spiral. In the case of a circle segment, the centre point 31 of the circle, as shown in FIG. 1, is slightly spaced away from the pivot bearing 32 of the segment 9. The bearing 32 passes through the grinding wheel axis 5 so that there is an eccentricity relative to the pivot of grinding wheel 2 which passes through the axis 5. However, the pivot bearing 32 may also be considered as the centre point of a spiral of which segment 9 represents one segmental portion. In that case, there is no need for eccentricity between the spiral centre and the grinding wheel axis 5. The circumferential path of the segment is largely identical in both cases and for this reason no drawing of the modification is provided.
The support member 3 which carries the bearing of the grinding wheel 2 is mounted for pivotal movement in a stationary bearing block 33 so that the central longitudinal line may assume various inclinations.
An indicator 22 which is provided with a scale is slidably mounted in a guide 35 and hinged to the support member 3 which carries the grinding wheel bearing. The guide 35 is non-displaceably hinged. The guide 35 is provided with a scale for the adjustment of a contact 23 which is adapted to be set to cooperate with an opposing contact mounted on the indicator 22. In practice, the highest and lowest positions in the course of revolution of a billet can be more easily read on the indicator 22 so that, starting from the lowest position, the contact 23 can be set to a specified height position. As mentioned, it is advisable to set the contact 22 to a height position which is 2% above the lowest position. From contact 23, a current signal lead directly to a selection switch 36 for an AND gate 37. Also applied to this contact switch 36 is a current signal from a switch 26. This switch 26 is subject to operation by a cruciform switching member 24 which revolves with the billet 14 and displaces a switching lever into its contact making position during this revolution in the manner already described. Preferably, the arrangement will be made such that a different switching state prevails during rotation through a central angular range 28° of 20° than in the two adjoining ranges 27 on either side each comprising 35° and extending to a corner of the billet 14. For a clearer understanding, these two anglular ranges 27, 28 are shown in FIG. 1.
The AND gate 37 allows selectively the contact 23 or the switch 26, or both these elements, to be processed as input signals by corresponding adjustment of the selection switch 36. An amplifier 38 processes the received signal in such a manner that, in accordance with the output of the amplifier 38, a field regulator 39 of a direct-current shunt-wound motor 25 can be set to two different values so that the rotational speed of the driving motor 25 is three times as fast during rotation through angular range 27 than it is during rotation through angular range 28.
An alternative arrangement for driving the semifinished product at a non-uniform speed is shown in FIG. 6. According to this arrangement there is provided an elliptical gear train 40 which is drivingly connected via gear wheel 41 to a driving motor revolving at constant speed. Jointly with gear wheel 41 an elliptical gear 42 rotates about one focus 43 thereof. Gear 42 is in mesh with an elliptical gear 44 which has the same size and revolves about its focus 45. There is also a rigid connection between gear 44 and an output gear 46. Gear 46 drives a gear or pinion 48 whose circumference is four times greater than that of gear 46. Consequently, in the course of one revolution of gear 48 there will be periodically four occasions of increased speed. The gear 48 is rotationally rigidly connected to the semifinished product or billet 14 in such a manner that an increased speed will be obtained in the angular range 27 adjacent the corners of the billet 14 relative to the angular range 28 between the corners of the billet 14. These angular ranges are shown in FIG. 1.
The extent of non-uniformity may be selected by a choice of the eccentricity e and the major axis a of the two congruent elliptical gears so that in this manner a suitably higher speed can be applied in the corner regions than in the central region of the semifinished product. | An apparatus grinding a steel billet to remove surface cracks. The billet is advanced in the direction of it longitudinal axis while being rotated. The apparatus includes a grinding wheel mounted in a bearing in a movably mounted support member. In order to accurately and simply control the penetration depth of the grinding wheel, a stop member is mounted on the support member. In one embodiment, the stop member is a segment of a circle mounted eccentrically relative to the grinding wheel. In another embodiment, the stop member is a segment of a spiral mounted coaxially with the grinding wheel. The stop member engages the surface of the billet. Two arrangements are described for rotating the billet at an increased speed while grinding the edge regions. | 1 |
BACKGROUND OF THE INVENTION
The present invention pertains to telephony and more particularly to a secure communications method for rapid authentication of users.
Authentication of a particular user is important for many electronic secure communications products which require a "training" session at the onset of communications in order to establish a communication link and to verify the identity of a caller and to assure the credibility of communications security.
Many secure communications systems suffer from lack of ease of use. Typically, a physical key, also known as a "crypto ignition key", is inserted into a secure communications device as a token signifying authorization to employ the device and to verify the key-bearer's credentials. This arrangement is generally satisfactory, but the key is subject to being stolen or lost. The user must also initiate a complicated procedure to use the secure communications device. Such systems require that the secure communications device include a receptacle for the key and associated electronics which adds to the size, weight and desktop footprint of the secure communications device. Further such devices are prohibitively expensive for commercial uses.
A particular problem against which secure commercial telecommunications devices need to defend is a scenario dubbed "the man in the middle", wherein a third party (the "man in the middle") wishing to intercept and/or alter privileged communications "taps" into the path between calling and called parties' secure communications devices with a pair of communications devices similar in nature to those of either or both of the calling and/or called parties. The pair are configured to intercept the communications and may conceivably "train" right along with the secure communications devices employed by the calling party and the called party.
Thus, what is needed is a secure, commercially economical authentication method for rapidly authenticating a user of commercial communications equipment.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a block diagram of a communication system interconnection of users in accordance with the present invention.
FIG. 2 is a flow chart of an authentication method in accordance with the present invention.
FIG. 3 is a data flow diagram of messages interchanged by users in accordance with the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The voice authentication method may be accomplished using a commercial secure telephone architecture. Examples of such commercial telephones include Micro MMT, Sectel 1500BDI, and most other Motorola secure phones manufactured by Motorola, Inc.
Refering to FIG. 1 commercial secure phones 1 and 2 are shown. Users are associated with these phones. A calling party is associated with phone 1 and a called party is associated with phone 2, for example. Phones 1 and 2 each include a vocoder 72 & 82 for voice compression and decompression, a microphone 70 & 80 for voice input, an earphone 71 & 81 for voice output, a commercial encryption/decryption function 73 & 83, and a modem 74 & 84 for transmitting data over the public switched network 3.
The voice templates are recorded using the vocoder 72 & 82 so that this will remain in the phone as the identity of the user in a compressed format. The voice templates are voice identification of a pre-record speech of a user, such as "My name is John Doe". These voice templates can be changed at any time when the phone is not active and has entered into the recording mode. The checksum of the voice template will be generated as a result of the voice template.
Refering to FIG. 3, the signalling between the two commercial secure phones is carried out in the following manner over a full duplex communications link. In order to achieve the signalling between the phones, a modem training sequence 40 (caller) & 41 (calling) must occur which will establish a digital link between the modems using industry standard modem call setup methodologies such as V.32 bis.
The next messages sent in the signalling sequence are the capabilities messages 42 & 43 which are pre-defined messages which determine what functions each phone is capable of performing. These capabilities describe such things as the negotiation of bit rates for data or voice, full duplex or half duplex, voice coder capabilities, and asynchronous or synchronous operation.
The public key exchange 44 & 45 will occur between each unit which allows a public key to be used by the other party for encrypting the voice sent across the link. Some examples of public key algorithms are: RSA, Diffie-Hellman, and Elliptic Curves.
The voice template 46 & 47 representing a digitized representation of the user's voice is sent acoss the link with a corresponding checksum of this template.
The voice templates 46 & 47 will go through an exclusive-OR process within each phone and the resulting checksum (48 & 49) is sent out covered using the public key from the other end.
Referring to FIG. 2, the flow chart describes what occurs within the commercial secure phone during the voice authentication sequence. During the data interchange, block 10, which includes initiating of the modem training sequence a local voice message is played for the user, block 12.
Once the modem link is established, block 14, the phones will begin the capabilities and key exchange, block 16. If the link is not established the phone will terminate the secure call setup, block 20, and return to normal (non-secure) voice communications.
The capabilities and key exchange will create the encrypted link, block 18, using the public key method. The phones 1 & 2 will exchange the digitized voice templates and the corresponding checksum, block 22.
The local voice template is exclusive ORed with the received template and a corresponding checksum is generated, block 24.
The resulting checksum of the templates should match, block 26 on each end of the link and to verify the checksum is sent using the encrypted link to the other phone. If the checksums do not match the call is terminated, block 20.
Once the checksum tests pass each commercial secure phone will enable the secure mode, block 32 and allow secure voice communications.
This invention is an important piece to the commercial security industry that has begun to emerge. Its importance is tied to two factors: (1) the voice authentication method combined with a preliminary message provides a gap to fill in time that the user has to wait for the secure conversation to begin (2) the associated voice template is used to authenticate the user you are talking to in a calling ID fashion (secure conversation can not begin until the template exchange is validated).
This invention is intended to provide a message to each party in the conversation such as "You are entering a secure conversation with . . . " followed by the voice template from the other party. So the resultant message would sound like "You are entering a secure conversation with John Doe". Each party can enter a special password instead of their name to create even higher levels of authentication only known by each party in the conversation.
This invention will inhibit the secure conversation until the voice template is validated. Thereby, defeating the "man in the middle" scenario whereas two extra secure phones are purchased and intentionally placed between the parties so as to eavesdrop on the content of the call.
Although the preferred embodiment of the invention has been illustrated, and that form described in detail, it will be readily apparent to those skilled in the art that various modifications may be made therein without departing from the spirit of the invention or from the scope of the appended claims. | The authentication method established a communication link between the calling and called users (14). The calling and called parties exchange voice identification data (22). The calling and called parties determine if the voice identification data compares (26,30). If voice identification data compares, a secure call is enabled (32). If the voice identification data does not compare the communication link is terminated (20). | 6 |
FIELD OF THE INVENTION
The present invention relates to the determination of received signal quality in a radio communication system.
BACKGROUND TO THE INVENTION
In a radio communication network, such as a mobile phone network, mobile stations monitor the quality of received signals and report the received signal quality back to a base station, typically in a control channel.
It has been proposed that a mobile station report received signal quality in a slow associated control channel (SACCH) using a three bit code. The signal quality is determined as the bit error rate (BER) of the received signal before channel decoding and is averaged over one SACCH multiframe, for example 480 ms.
The BER is only used if the a block is correctly received, i.e. it passes a CRC (cyclic redundancy code) check. If a block is not correctly received, a default notional BER of, for example 50%, is assumed.
SUMMARY OF THE INVENTION
According to a first aspect of the present invention, there is provided a method of generating a received signal quality signal in a communication system, the method comprising:
receiving a signal from a physical channel; extracting a transport channel format combination indicator from the received signal; processing one or more transport channel signals, contained in the received signal, in accordance with the extracted transport channel format combination indicator; said processing including at least channel decoding; and generating a received signal quality signal in dependence on the quality of the or each transport channel signal prior to channel decoding.
According to the first aspect of the present invention, there is also provided a communication device comprising:
a receiver for receiving a signal from a physical channel; processing means configured for:
extracting a transport channel format combination indicator from the received signal; processing one or more transport channel signals, contained in the received signal, in accordance with the extracted transport channel format combination indicator; said processing including at least channel decoding; and generating a received signal quality signal in dependence on the quality of the or each transport channel signal prior to channel decoding.
The or each transport channel signal may comprise a sequence of data blocks. The quality of the or each transport channel signal may be represented by a block bit error rate determined prior to channel decoding. The determined bit error rate of a transport channel signal may be averaged over period comprising a plurality of data blocks. In the case of there being a plurality of transport channel signals, the bit error rates of each transport channel signal may be averaged over the same period. An average bit error rate may be calculated across the transport channel signals with the averaging being weighted in dependence on the transport formats used for said transport signals.
The received signal quality signal may be transmitted in a control channel.
According to a second aspect of the present invention, there is provided a method of generating a received signal quality signal in a communication system, the method comprising:
receiving a signal from a physical channel, the signal comprising one or more transport channels; extracting a transport channel format combination indicator from the received signal and determining the bit error rate therefore; and generating a received signal quality signal in dependence on the bit error rate of the extracted transport channel format combination indicator.
According to the second aspect of the present invention, there is also provided a communication device comprising:
a receiver for receiving a signal from a physical channel, the signal comprising one or more transport channels; and processing means configured for:
extracting a transport channel format combination indicator from a received signal and determining the bit error rate therefore; and generating a received signal quality signal in dependence on the bit error rate of the extracted transport channel format combination indicator.
The determined bit error rates of a plurality of transport channel format combination indicator instances may be averaged.
The received signal quality signal may be transmitted in a control channel.
According to a third aspect of the present invention, there is provided a method of generating a received signal quality signal in a communication system, the method comprising:
receiving a signal from a physical channel, the signal comprising a plurality of bursts each including a training sequence; and generating a received signal quality signal in dependence on the bit error rate of the training sequence of a received burst.
According to the third aspect of the present invention, there is also provided a communication device comprising:
a receiver for receiving a signal from a physical channel, the signal comprising a plurality of bursts each including a training sequence; and processing means configured for generating a received signal quality signal in dependence on the bit error rate of the training sequence of a received burst.
The determined bit error rates of the training sequences of a plurality of bursts may be averaged.
The bit error rate of a training sequence may be produced by comparing a received training sequence with a reference training sequence.
The received signal quality signal may be transmitted in a control channel.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a mobile communication system according to the present invention;
FIG. 2 is a block diagram of a mobile station;
FIG. 3 is a block diagram of a base transceiver station;
FIG. 4 illustrates the frame structure;
FIG. 5 illustrates a packet data channel;
FIG. 6 illustrates the sharing of a radio channel between two half-rate packet channels;
FIG. 7 illustrates the lower levels of a protocol stack;
FIG. 8 is a block diagram illustrating the processing of the transport channels of a received physical layer signal;
FIG. 9 is a block diagram illustrating received signal quality determination;
FIG. 10 is a flowchart of a first part of a received signal quality determination process;
FIG. 11 is a flowchart of a second part of a received signal quality determination process;
FIG. 12 is a block diagram illustrating another approach to signal quality determination;
FIG. 13 is a flowchart illustrating another received signal quality determination process;
FIG. 14 is a block diagram illustrating yet another approach to signal quality determination; and
FIG. 15 is a flowchart illustrating yet another received signal quality determination process.
DETAILED DESCRIPTION OF EMBODIMENTS
Embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings.
Referring to FIG. 1 , a mobile phone network 1 comprises a plurality of switching centres including first and second switching centres 2 a , 2 b . The first switching centre 2 a is connected to a plurality of base station controllers including first and second base station controllers 3 a , 3 b . The second switching centre 2 b is similarly connected to a plurality of base station controllers (not shown).
The first base station controller 3 a is connected to and controls a base transceiver station 4 and a plurality of other base transceiver stations. The second base station controller 3 b is similarly connected to and controls a plurality of base transceiver stations (not shown).
In the present example, each base transceiver station services a respective cell. Thus, the base transceiver station 4 services a cell 5 . However, a plurality of cells may be serviced by one base transceiver station by means of directional antennas. A plurality of mobile stations 6 a , 6 b are located in the cell 5 . It will be appreciated what the number and identities of mobile stations in any given cell will vary with time.
The mobile phone network 1 is connected to a public switched telephone network 7 by a gateway switching centre 8 .
A packet service aspect of the network includes a plurality of packet service support nodes (one shown) 9 which are connected to respective pluralities of base station controllers 3 a , 3 b . At least one packet service support gateway node 10 connects the or each packet service support node 10 to the Internet 11 .
The switching centres 3 a , 3 b and the packet service support nodes 9 have access to a home location register 12 .
Communication between the mobile stations 6 a , 6 b and the base transceiver station 4 employs a time-division multiple access (TD MA) scheme.
Referring to FIG. 2 , the first mobile station 6 a comprises an antenna 101 , an rf subsystem 102 , a baseband DSP (digital signal processing) subsystem 103 , an analogue audio subsystem 104 , a loudspeaker 105 , a microphone 106 , a controller 107 , a liquid crystal display 108 , a keypad 109 , memory 110 , a battery 111 and a power supply circuit 112 .
The rf subsystem 102 contains if and rf circuits of the mobile telephone's transmitter and receiver and a frequency synthesizer for tuning the mobile station's transmitter and receiver. The antenna 101 is coupled to the rf subsystem 102 for the reception and transmission of radio waves.
The baseband DSP subsystem 103 is coupled to the rf subsystem 102 to receive baseband signals therefrom and for sending baseband modulation signals thereto. The baseband DSP subsystems 103 includes codec functions which are well-known in the art.
The analogue audio subsystem 104 is coupled to the baseband DSP subsystem 103 and receives demodulated audio therefrom. The analogue audio subsystem 104 amplifies the demodulated audio and applies it to the loudspeaker 105 . Acoustic signals, detected by the microphone 106 , are pre-amplified by the analogue audio subsystem 104 and sent to the baseband DSP subsystem 4 for coding.
The controller 107 controls the operation of the mobile telephone. It is coupled to the rf subsystem 102 for supplying tuning instructions to the frequency synthesizer and to the baseband DSP subsystem 103 for supplying control data and management data for transmission. The controller 107 operates according to a program stored in the memory 110 . The memory 110 is shown separately from the controller 107 . However, it may be integrated with the controller 107 .
The display device 108 is connected to the controller 107 for receiving control data and the keypad 109 is connected to the controller 107 for supplying user input data signals thereto.
The battery 111 is connected to the power supply circuit 112 which provides regulated power at the various voltages used by the components of the mobile telephone.
The controller 107 is programmed to control the mobile station for speech and data communication and with application programs, e.g. a WAP browser, which make use of the mobile station's data communication capabilities.
The second mobile station 6 b is similarly configured.
Referring to FIG. 3 , greatly simplified, the base transceiver station 4 comprises an antenna 201 , an rf subsystem 202 , a baseband DSP (digital signal processing) subsystem 203 , a base station controller interface 204 and a controller 207 .
The rf subsystem 202 contains the if and rf circuits of the base transceiver station's transmitter and receiver and a frequency synthesizer for tuning the base transceiver station's transmitter and receiver. The antenna 201 is coupled to the rf subsystem 202 for the reception and transmission of radio waves.
The baseband DSP subsystem 203 is coupled to the rf subsystem 202 to receive baseband signals therefrom and for sending baseband modulation signals thereto. The baseband DSP subsystems 203 includes codec functions which are well-known in the art.
The base station controller interface 204 interfaces the base transceiver station 4 to its controlling base station controller 3 a.
The controller 207 controls the operation of the base transceiver station 4 . It is coupled to the rf subsystem 202 for supplying tuning instructions to the frequency synthesizer and to the baseband DSP subsystem for supplying control data and management data for transmission. The controller 207 operates according to a program stored in the memory 210 .
Referring to FIG. 4 , each TDMA frame, used for communication between the mobile stations 6 a , 6 b and the base transceiver stations 4 , comprises eight 0.577 ms time slots. A “26 multiframe” comprises 26 frames and a “51 multiframe” comprises 51 frames. Fifty one “26 multiframes” or twenty six “51 multiframes” make up one superframe. Finally, a hyperframe comprises 2048 superframes.
The data format within the time slots varies according to the function of a time slot. A normal burst, i.e. time slot, comprises three tail bits, followed by 58 encrypted data bits, a 26-bit training sequence, another sequence of 58 encrypted data bits and a further three tail bits. A guard period of eight and a quarter bit durations is provided at the end of the burst. A frequency correction burst has the same tail bits and guard period. However, its payload comprises a fixed 142 bit sequence. A synchronization burst is similar to the normal burst except that the encrypted data is reduced to two clocks of 39 bits and the training sequence is replaced by a 64-bit synchronization sequence. Finally, an access burst comprises eight initial tail bits, followed by a 41-bit synchronization sequence, 36 bits of encrypted data and three more tail bits. In this case, the guard period is 68.25 bits long.
When used for circuit-switched speech traffic, the channelization scheme is as employed in GSM.
Referring to FIG. 5 , full rate packet switched channels make use of 12 4-slot radio packets spread over a “51 multiframe”. Idle slots follow the third, sixth, ninth and twelfth radio packet.
Referring to FIG. 6 , for half rate, packet switched channels, both dedicated and shared, slots are allocated alternately to two sub-channels.
The baseband DSP subsystems 103 , 203 and controllers 107 , 207 of the mobile stations 6 a , 6 b and the base transceiver stations 4 are configured to implement two protocol stacks. The first protocol stack is for circuit switched traffic and is substantially the same as employed in conventional GSM systems. The second protocol stack is for packet switched traffic.
Referring to FIG. 7 , the layers relevant to the radio link between a mobile station 6 a , 6 b and a base station controller 4 are the radio link control layer 401 , the medium access control layer 402 and the physical layer 403 .
The radio link control layer 401 has two modes: transparent and non-transparent. In transparent mode, data is merely passed up or down through the radio link control layer without modification.
In non-transparent mode, the radio link control layer 401 provides link adaptation and constructs data blocks from data units received from higher levels by segmenting or concatenating the data units as necessary and performs the reciprocal process for data being passed up the stack. It is also responsible for detecting lost data blocks or reordering data block for upward transfer of their contents, depending on whether acknowledged mode is being used. This layer may also provide backward error correction in acknowledged mode.
The medium access control layer 402 is responsible for allocating data blocks from the radio link control layer 401 to appropriate transport channels and passing received radio packets from transport channels to the radio link control layer 403 .
The physical layer 403 is responsible to creating transmitted radio signals from the data passing through the transport channels and passing received data up through the correct transport channel to the medium access control layer 402 .
Referring to FIG. 8 , data produced for applications 404 a , 404 b , 404 c propagates up the protocol stack from the medium access control layer 402 . The data from the applications 404 a , 404 b , 404 c can belong to any of a plurality of classes for which different qualities of service are required. Data belonging to a plurality of classes may be required by a single application. The medium access control layer 402 directs data to the applications 404 a , 404 b , 404 c from different transport channels 405 , 406 , 407 according to class to which it belongs.
Each receive transport channel 405 , 406 , 407 can be configured to process received signals according to a plurality of processing schemes 405 a , 405 b , 405 c , 406 a , 406 b , 406 c , 407 a , 407 b , 407 c . The configuration of the transport channels 405 , 406 , 407 is established during call setup on the basis of the capabilities of the mobile station 6 a , 6 b and the network and the nature of the application or applications 404 a , 404 b , 404 c being run.
The processing schemes 405 a , 405 b , 405 c , 406 a , 406 b , 406 c , 407 a , 407 b , 407 c are unique combinations of cyclic redundancy check 405 a , 406 a , 407 a , channel decoding 405 b , 406 b , 407 b and rate matching 405 c , 406 c , 407 c . These unique processing schemes are the reciprocals of transmitter processing schemes which define different “transport formats”. An interleaving scheme may be selected for each transport channel 405 , 406 , 407 and require corresponding de-interleaving 405 d , 406 d , 407 d . Thus, different transport channels may use different interleaving schemes and, in alternative embodiments, different interleaving schemes may be used at different times by the same transport channel.
The combined data rate produced for the transport channels 405 , 406 , 407 must not exceed that of physical channel or channels allocated to the mobile station 6 a , 6 b . This places a limit on the transport format combinations that can be permitted. For instance, if there are three transport formats TF 1 , TF 2 , TF 3 for each transport channel, the following combinations might be valid:
TF 1 TF 1 TF 2 TF 1 TF 3 TF 3
but not
TF 1 TF 2 TF 2 TF 1 TF 1 TF 3
The received signal is de-interleaved 411 and then demultiplexed by a demultiplexing process 410 , which outputs transport channel signals to respective transport channel de-interleaving processes 405 d , 406 d , 407 d.
A transport format combination indicator is spread across one radio packet with portions placed in fixed positions in each burst, on either side of the training symbols ( FIG. 9 ) in this example. The complete transport format combination indicator therefore occurs at fixed intervals, i.e. the block length 20 ms. This makes it possible to ensure transport format combination indicator detection when different interleaving types are used e.g. 8 burst diagonal and 4 burst rectangular interleaving. Since the transport format combination indicator is not subject to variable interleaving, it can be readily located by the receiving station and used to control processing of the received data.
The transport format combination indicator is extracted from the received data stream by a transport format combination indicator extraction process 414 after the deinterleaving process 411 .
The transport format combination indicator from the transport format combination indicator extraction process 414 is decoded by a decoding process 413 . The decoded transport format combination indicator is then processed by a transport format combination detecting process 412 which provides information on the current transport format combination to the medium access control layer 402 . This information is then used in the medium access control layer 402 to select the appropriate decoding and de-interleaving process for the transport formats used in the received signal.
FIG. 9 illustrates received signal quality determination in the case where the received physical layer signal carries a data stream comprising three transport channels using respective formats. Of course, the data stream may comprise more or fewer transport channels and the same transport format may be used by more than one of the transport channels.
Referring to FIG. 9 , first, second and third transport channel quality determiners 501 , 502 , 503 receive the cyclic redundancy check results from respective cyclic redundancy check processes 405 a , 406 a , 407 a and a bit error rate estimate from respective channel decoding processes 405 b , 406 b , 407 b.
The operation of the first transport channel quality determiner 501 will now be described with reference to FIG. 10 .
Referring to FIG. 10 , at the start of a SACCH multiframe period (also known as the SACCH reporting period), the CRC result for a first transport block is received from the first cyclic redundancy check process 405 a (step s 1 ). If the result is determined to be true, i.e. the CRC is correct, (step s 2 ), the BER for the first transport block is obtained from the first channel decoder 405 b (step s 3 ) and stored (step s 4 ). A block counter is then incremented (step s 5 ). It is then determined whether the current SACCH multiframe period has come to an end (step s 6 ).
If the current SACCH multiframe period has not come to an end (step s 6 ), the program flow returns to step s 1 where the CRC for the next block is obtained.
If, at step s 2 , it is determined that the cyclic redundancy check result is determined to be false, steps s 3 to s 5 are skipped.
When all of the blocks of the current the current SACCH multiframe period have been processed (step s 6 ), the BER is averaged over a period corresponding to the product of the block period and the number of correctly received transport blocks, i.e. the value accumulated by the step s 5 .
The second and third transport channel quality determiners 502 , 503 operate in the same way as the first transport channel quality determiners 501 except that the cyclic redundancy check result and the BER estimates are obtained from the corresponding cyclic redundancy check process 406 a , 407 a and channel decoders 406 b , 407 b.
The transport channel quality determiners 501 , 502 , 503 output their average BERs and transport block counts to a physical channel quality determiner 504 .
The operation of the physical channel quality determiner 504 will now be described with reference to FIG. 11 .
Referring to FIG. 11 , the physical channel quality determiner 504 obtains the TFCI applicable to the most recent transport channel quality determinations (step s 11 ) and then receives the transport block counts from the transport channel quality determiners 501 , 502 , 503 (step s 12 ).
The TFCI information determines what percentage of each radio packet is used by each transport channel. This information is used to convert the transport block counts into the percentage of the data in the transmitted data stream that was correctly received in one SACCH multiframe, according to:
P = ∑ c = 1 n b ( c ) · p ( c ) b T ( c )
where c is the transport channel number, n is the number of transport channels, b is the number of correctly received bits in the transport block, b t is the number of bits in the transport block in the transmitted signal and p is the percentage of the data stream used by a particular transport channel.
If the result P is greater than or equal to 50%, the BERs are obtained from the transport channel quality determiners 501 , 502 , 503 (step s 15 ). The BERs are then averaged (step s 16 ). In the present embodiment, the BERs are averaged in accordance with the following:
B = ∑ c = 1 n b ( c ) · p ( c ) ∑ c = 1 n p ( c )
where B is the average BER.
If, however, the percentage of the data in the transmitted data stream that was incorrectly received is greater than 50% (step s 14 ), the average bit error rate B is set arbitrarily to 50%.
The average bit error rate B is then quantized and encoded into 3 bits which are made available for transmission to a base transceiver station 4 by the mobile station 6 a in the SACCH as a received signal quality report.
It will be appreciated that the formulae given above are examples of the effect required and that the value ranges and scaling factors actual used may vary.
A second embodiment of the present invention will now be described.
A mobile station is as described above with the exception of the generation of the received signal quality report. In this embodiment, the report is based on the quality of the TFCI signal.
Referring to FIG. 12 , TFCI BERs are fed from the TFCI decoder 413 ( FIG. 8 ) to a received signal quality determiner 601 . The received signal quality determiner 601 generates a received signal quality signal in dependence on the TFCI BERs from the TFCI decoder 413 and outputs it for transmission in the SACCH.
Referring to FIG. 13 , the received signal quality determiner 601 obtains a first TFCI BER for the first TFCI transmitted in a SACCH multiframe period (step s 31 ) and stores it (step s 32 ). Successive TFCI BERs are then obtained (step s 31 ) and stored (step s 32 ) until the BER for the last TCFI of the current SACCH multiframe period ends (step s 33 ).
When the last BER has been obtained and stored, the stored BERs are averaged (step s 34 ) and then the average quantized and encoded (step s 35 ) and output (step s 36 ) for transmission to a base transceiver station 4 by the mobile station 6 a in the SACCH as a received signal quality report.
A third embodiment of the present invention will now be described.
A mobile station is as described above with the exception of the generation of the received signal quality report. In this embodiment, the report is based on the quality of the received training sequences.
As shown in FIG. 4 , each burst comprises a training sequence sandwiched between two blocks of data bits. The training sequences are predetermined.
Referring to Referring to FIG. 14 , received training sequences are fed to a received signal quality determiner 701 . The received signal quality determiner 701 generates a received signal quality signal in dependence on the received training sequences and outputs it for transmission in the SACCH.
Referring to FIG. 12 , TFCI BERs are fed from the TFCI decoder 413 ( FIG. 8 ) to a received signal quality determiner 601 . The received signal quality determiner 601 generates a received signal quality signal in dependence on the TFCI BERs from the TFCI decoder 413 and outputs it for transmission in the SACCH.
Referring to FIG. 15 , the received signal quality determiner 701 obtains a first training sequence in a SACCH multiframe period (step s 41 ) and compares it with a reference copy (step s 42 ). The number of differences between the received training sequence and the reference is added to a record of the errors for the current SACCH multiframe period (step 43 ). The errors in successive training sequences are then obtained (step s 42 ) and added to the error record (step s 43 ) until the training sequence of the last burst in the current SACCH multiframe period has been processed (step s 44 ).
When the last training sequence has been processed, the accumulated error count is quantized (step s 45 ) and output (step s 46 ) for transmission to a base transceiver station 4 by the mobile station 6 a in the SACCH as a received signal quality report. The three embodiments described above may be combined to produce additional embodiments. For instance, bit error rates obtained by two or three techniques may be averaged to produce a bit error rate that is then quantized, encoded and transmitted to a base transceiver station 4 by the mobile station 6 a in the SACCH as a received signal quality report.
It is to be understood that the foregoing embodiments are merely examples and that many modifications are possible without departing from the spirit and scope of the appended claims. | A method of generating a received signal quality signal in a communication system, the method comprising: receiving a signal from a physical channel, extracting a transport channel format combination indicator from the received signal, processing one or more transport channel signals, contained in the received signal, in accordance with the extracted transport channel format combination indicator, said processing including at least channel decoding, and generating a received signal quality signal in dependence on the quality of the or each transport channel signal prior to channel decoding. | 7 |
BACKGROUND OF THE INVENTION
This invention belongs to the field of the treatment of flat, absorptive, compressible web materials with liquids such as treating liquor or finishing baths. In particular, the invention relates to a method for the continuous application of liquors, especially finishing liquors, on absorptive and compressible material webs, in particular fibrous webs such as textile webs, which are made to advance in a continuous and uniform manner from a supply, e.g. a spool, to a winding-on device or equivalent.
This invention is also related to apparatuses for carrying out the method.
The following description makes reference to the general case where advancing textile fiber webs are concerned. However, other absorptive, compressible webs may be substituted therefor such as certain papers, spongeous materials, synthetic and natural fiber vleeces, etc to which this invention also applies.
The instant invention refers to a method wherein such amounts of liquor are applied in one or several steps that the maximum amount of liquor which the web can take up by absorption, called the absorptivity limit, is not reached but where those amounts are greater than the water retention value of the web. The water retention value is a physical property of the web and may be determined by the DIN standard no. 53'814 (ASTM-D2402-65T). Processes where the absorptivity limit is reached and the liquor excess is removed afterwards, thus in particular the pad mangle methods, are outside the scope of this invention.
Quite a number of methods and working techniques are known in the textile processing art which are used to apply liquors of treating bathes to textile fiber webs. The term "web" comprises, in a known manner, a textile substrate which may absorb liquids, whose length is very great compared to its width, e.g. by about 500 to 10,000 times, and whose thickness is comprised between one and about ten times the diameter of the constituting fiber. This term "web" therefore comprises, besides the woven fabrics, also knitted fabrics and other non-woven webs such as vleeces. It further comprises rows or layers of parallel warp yarns which are to be sized, bleached or dyed before weaving. In these cases, the overall thickness of the web may even be greater. Examples of such techniques are the padding, the kiss roller application, the different methods of impregnation, the spraying, the application of liquors with sponges, the application of foamed liquors and the printing. In many cases, it is necessary or appropriate to apply first an excess of liquor and to remove that excess afterwards. An important example of the latter method is the pad mangle where the textile web is offered as much liquor as it may take up, and any excess is removed between squeeze rollers. It is not possible to remove any liquor in excess over the above-mentioned water retention value. Using technically reasonable squeezing pressures, the amount of liquor remaining in the web after squeezing is higher than that value. Without squeezing, the applied amount of liquor called "pickup" cannot be metered or controlled.
An important process for the application of liquors, especially of treating liquors, on textile webs is a method introduced in the '70s and called "MA process" (MA stands for minimum application) which brings about a uniform, controlled impregnation without local or overall excess application of liquors on textile material webs under high working speeds. It is disclosed, for example, as well as a preferred apparatus for its implementing, in U.S. patent specification nos. 3,862,553 and 3,822,834. It does not comprise any squeezing device. The minimum application amount is defined as that liquor amount in % by weight which is in the range between zero and a value given by the expression (W 2 /150)+40 wherein W is the above defined water retention value. The upper limit of the amount of applied liquor, defined by the above-indicated expression, is situated at about 10 to 30% by weight of the limit of the squeezable excess. The process has found world-wide application and introduction, it is well known to the people skilled in the art, and it is deemed unnecessary to mention its advantages herein.
Although the process just mentioned has been known as a "minimum application" method, it may also be used to apply greater amounts of liquors in a metered, controlled and uniform manner. This alternative and generalized technique is named in the following as "metering roller application" and comprises the minimum application as well. This metering roller application technique therefore comprises all applications resulting in applied amounts between the value of W and the saturation value (absorption limit) of the substrate.
The application of about 10 to 25 % by weight of preferably aqueous liquors on dry hydrophilic textile webs, i.e. webs containing not more than about 15% by weight of natural or residual humidity, is easy in that a uniform one-side application will be homogeneously spread and distributed throughout the textile material due to capillary forces. However, it may happen even in the minimum application method that particularly weakly fiber affine and viscous liquors will give an uneven or undesirably one-sided application result.
In the case of greater application quantities, the time duration available for the homogeneous distribution of the applied liquor in the material web which is given by the dwell time of the web between the applicator device and the drying means, will sometimes not be sufficient so that inhomogenities are observed. Similar phenomena occur when the web to be loaded with a liquor already contains another one; in this case, the uneven liquor distribution is even more significant since the liquor distribution within the web material is based here essentially on liquid-liquid diffusion, a process which is significantly slower than a distribution by capillarity.
A uniform liquor or bath distribution in the cases just discussed has been achieved until now by dwelling techniques where the web is wound up and abandoned for a longer time. Dwelling techniques, however, are material, space and capital consuming.
Another approach to achieve a uniform liquor distribution are the pad mangle techniques which do not, however, belong to the instant field of invention. Further advantages of this approach, besides the already mentioned limitation in application control, are expensive machinery, technically complicated operation and the fact that, when webs already containing a liquor are used, this liquor is partially squeezed out together with the impregnation second liquor.
It has already been suggested to pass a sizing liquor containing web formed by rows of parallel and horizontal warp yarns through a squeezing device having squeezing rollers. It is not known whether an equalizing of the sizing liquor may be obtained; anyway the mere squeezing is an uncontrolled operation, and generally part of the sizing liquor is squeezed out of the warp yarns which is not desired.
Swiss patent specification no. 530,230 casually mentions that the uniform impregnation of a textile material by a finishing liquor may be enhanced at particularly adverse conditions by special measures such a mechanical means. However, this reference exclusively deals which the minimum application defined above where, in detrimental cases of the liquor distribution, the use of squeezing means may accelerate this distribution. Experiments have nevertheless shown that the uniformity of distribution is a feature characteristic for the minimum application, and thus the use of squeezing means could not give a model to cases where there is a squeezable liquor excess in the web material.
Squeezing devices are composed of at least one pair of cooperating rollers; at leas one roller of the pair is provided with a rubber elastic surface or is totally made from rubber. The material web is passed between the rollers and pinched by them. A squeezing effect is obtained in that the two rollers are pressed against each other, the elastic surface of the rubber roller flattens in the contact region, and exerts a squeezing action. An adjustment of the squeezing effect is, as in the pad mangle, only possible in very narrow limits. It has been found that such a squeezing device is not fitted for the invention and cannot be used.
SUMMARY OF THE INVENTION
There is a first and major object of this invention to eliminate the problems and drawbacks of uneven distribution of squeezable amounts of liquors in absorptive material webs and to provide a method for an even, homogeneous distribution of such liquors in compressible material webs.
A further object of the invention is to provide such a method which is a continuous one and can be integrated without difficulty into a general process line for the application of liquors, particularly finishing liquors, on absorptive and compressible material webs.
Still another object is to provide an equalizing method of the depicted kind which allows to adjust, to control and to maintain constant the equalizing effect on which the method is based.
A further object of this invention is to provide an equalizing method as outlined above where the equalizing effect can easily be monitored without a permanent, overall squeezing out of liquor from the liquor carrying absorptive material web.
Another objects of the invention are apparatuses permitting the performance of the above defined processes in a simple, inexpensive way, allowing perfect control and monitoring of the equalizing effects.
Now, the above detailed objects and still others are implemented by the process of the invention which comprises the passage of the liquor loaden material web through an equalizing device wherein the said material web is temporarily and continuously compressed, as it advances through the device, to a predetermined, adjustable thickness which is smaller than the thickness of the material web before it enters the equalizing device. The compression is effected in such a manner that there is no liquor added to or removed from the material web in the equalizing zone, only a liquor equalizing effect being obtained within the material web. Therefore, the amount of liquor in the material web remains substantially the same upstream and downstream the equalizing device.
It has been found that the liquor within the material web can effectively be equalized to give a perfectly homogeneous distribution therein, when the liquor containing material web is compressed by a determined amount, referred to the condition before compression, that the amount of compression is in the first place a function of the liquor content of the web but also of its structure, and that the amount of compression must therefore be adjustable to adapt it to the actual conditions. It will be evident that these basic findings could not be derived from the condition of squeezing a web using unqualified, high pressures and not using a compression nip or slit.
The effect of the depicted adjustable compression is to merely redistribute the liquor within the material web, in establishing a contact of regions of the web which contain relatively high amounts of liquor, with those containing relatively low liquor amounts, without squeezing liquor out of the web.
The invention provides a novel, unique and universal conception bringing about a rapid, unform and controllable impregnation of material webs with liquor and which can be combined with any application method where the uniformity of distribution should be improved. The new method is particularly advantageous in spraying methods which are elegant but do not give a uniform liquor distribution. A preferred use of the method is together with the metering roller application process. The material web is compressed in the equalizing device by passing it through a slit or a nip whose thickness is comprised between zero and the thickness of the web before entering the slit or nip. The adjustment of the nip depends upon several factors, the purpose being the mere redistribution, i.e. equalization, of liquor in the interior of the material web. The most important factors are the compressibility of the liquor containing web, its thickness, and its liquor content. Further factors are the physical properties of liquor and material web and the degree of irregularity of the applied liquor.
In practice, it is not necessary to known all these factors. It is before all necessary to operate the equalizing device in such a manner that there is no overall squeezing out of liquor at the equalizing nip. A short-lasting appearance of squeezed liquor is normal since a local liquor excess belongs to the nature of irregular application. This short-lasting appearance of squeezed liquor may advantageously be used to control and adjust the thickness of the nip as it will be described later.
Generally, it is necessary to determine the liquor amount per unit area or weight of the material web upstream the equalizing device and to compare it with predetermined values in order to obtain and to keep constant the desired amount of liquor in the material web. For gross results, one measuring position will be sufficient, namely between liquor application device and equalizing device. In this case, the basic weight of the raw material web before impregnation must be known and input. Better results are obtained when the data of the raw web are continuously measured too. Furthermore, the basic weight of the material web after equalizing may be measured to supply a control value for adjusting the equalizing device. This is to be explained later.
The measuring of the above mentioned data is known per se and may be realized by radiation or wave absorption.
In the process of the invention, the material web to be impregnated is first introduced, as usual, into a feeding device. Such devices either comprises two rollers forming a small nip through which the material web is passed, at least one of the rollers being positively driven, or comprise a single driven roller having an anti-skid surface, which is contacted by the web over an angle of at least 180°. The web is then led either directly or over guide, compensating and/or spreading rollers to the liquor application device.
The preferred application device which may also be provided twice or more times, i.e. the metering roller applicator is either the one known from U.S. Pat. No. 3,862,553, the MA applicator, or a new development made by the applicant and disclosed in U.S. Pat. No. 4,672,705. The construction of the devices and their function is in detail disclosed in these patents which are therefore incorporated herein by reference.
The process of the invention may also be realized together with other application devices, known to the man skilled in the art. Pad mangling where an excess of liquor is squeezed out of a web is not suitable. The selected application method may provide an irregular application. However, constant lengthwise or transverse strips as irregularities are to be avoided.
The slit or nip of the equalizing device may be realized in different manners. Generally, a nip is formed between two rollers, one of them having preferably a rubber elastic surface or being fully made from rubber. This roller will be driven. The other roller should have a harder surface and may also be driven.
For the adjustment of the roller nip, one roller is approached to the other. This motion may be best effected by a screw spindle actuator. It is preferred to provide additional means in order to retract rapidly one roller from the other in order to avoid web breakage on the appearance of sewed seams or other thickened portions. This rapid release may be effected by a hydraulically actioned toggle lever mechanism. The man in the art is aware of suitable solutions.
It is appropriate to equip the hard surface roller with means for heating for cooling. Means may be provided to steam the web from the outside in order to avoid liquor evaporation when the roller is heated.
The slit may also be formed between solid surfaces facing one another with a short distance and preferably provided with an elastic surface layer having a low frictional coefficient.
More than one equalizing devices may be provided in succession. When rollers are used for equalizing, they may be mounted in any arrangement whatsoever; however, their axes must be parallel. The common plane of the two axes may thus be horizontal, vertical or at any angle. The web may further contact one or both rollers at any desired angle.
After leaving the equalizing device, the material web will be processed as usual, generally it will be dried in a continuously operated dryer, in particular a tenter frame which is equipped with the conventional auxiliary devices. Finally, the web will be wound on a roll.
The invention now allows to eliminate irregularities of liquor distribution which are often observed in the use of known application techniques and which had until now to be accepted or circumvented by the use of other, complex application or impregnation methods. Furthermore, it is now possible to apply successively two or more different liquors which are not compatible in mixture and which can now be mixed and uniformly distributed in the web material itself. The invention allows to obtain a controlled and metered liquor application being constant independently on the web travelling speed.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will now become more fully understood from the detailed description of preferred embodiments thereof, given hereinbelow, and the accompanying drawings which are given for illustration purposes only and thus are not limitative of the invention.
In the drawings, all FIGURES are partly sectioned, schematical side elevations of the apparatuses of the invention.
FIG. 1 shows a general embodiment of the device,
FIG. 2 is a variant of the device shown in FIG. 1,
FIG. 3 shows another embodiment of the equalizing device of FIG. 1, and
FIG. 4 represents an embodiment of a portion of the device of FIG. 1 showing a metering roller applicator system.
All figures are schematical representations only for showing roughly the web travel path. Same reference numerals refer to identical or functionally equivalent elements. The process of the invention will be understood from the drawings and the following description.
DESCRIPTION OF PREFERRED EMBODIMENTS
A preferred embodiment of the apparatus of the invention is schematically shown in FIG. 1. Auxiliary devices such as circulation or feeder pumps, liquor containers, machine frames and supports, motors, control and metering units, computers etc. are not shown; they are known to the people skilled in the art.
The apparatus is first equipped with a web feeding device represented by the roller 12. The incoming material web 20, unwound from a roll 18, contacts the driven feeder roller 12 which has an anti-skid surface, by about 270°. It is .then fed to the web tension compensator over a deflection roller 11. The web tension is controlled by the up-and-down motion of a compensating roller 10. The web then passes through the contact-free measuring unit 28, 28' which measures the thickness, the basic weight and the humidity content of the web, and it goes then through the arcuated rollers system 24 where the web is smoothed and winkles are stretched out. The system 24 is normally necessary for knitted fabrics and may be foregone with stronger fabrics such as shirt fabrics.
The material web is then fed into an applicator device 22 which may be constructed as desired and which effects a more or less uniform, controlled, metered liquor application whose amount is comprised between the value of the water retention capacity of the substrate, determined according ASTM-D2402-65T corresponding to German standard DIN 53'814 and Swiss standard SNV 98'592, and the saturation value. The applicator device may be a roller, foam or spray application device.
The unit 22 may also be provided twice or more times when is suitable or necessary to apply partial liquors, e.g. in reactive dyeing.
The web now traverses another basic weight measuring unit 26, 26' which determines, in cooperation with the unit 28, 28', the amount of liquor applied.
The web then enters the equalizing device 30 which comprises two rollers 32 and 34 of the same diameter which are driven with the same superficial speed than the travelling speed of the web 20. The axes of the rollers lie in a vertical plane. The upper roller 32 is stationary whereas the lower roller 34 having a rubber surface coating, may be raised and lowered by the pneumatic, hydraulic or electric motor 36. The two rollers may also be interchanged.
A liquor sensor 40 is provided within the free space in front of the nip 41 of the rollers 32, 34 and laterally from the web 20. The sensor is designed to detect liquor portions which may be temporarily squeezed out of the web and which will be present as tiny bulbs. The liquor sensor 40 may be constructed in any known manner. It may, for example, sense the liquid level by surface contact, or it may operate based on electrical, magneto-electrical (Hall effect) or reflectory parameters such as light from an infrared or a laser source, other radiations such as beta or gamma radiations, soft X-rays, corpuscular radiation, etc. The sensor 40 is preferably adapted to sense or scan periodically over the width of the web 20, for example with a scanning frequency of some Hertz. It is only essential that the sensor 40 supplies a signal representative of a true information about the presence or absence of liquor at any location in front of the roller nip 41.
The web 20 now is conducted into the drier 46 and is finally wound up on the roll 16.
Instead of a real, physical material web 20, rows of parallel yarns forming one or more horizontal layers, for example warp yarn layers, may also be used and treated.
The device comprises furthermore control and metering means to reach the purpose of the invention. In the applicator control unit 50 having the regulator 52, the liquor amount to be applied by the applicator unit 22 is adjusted and maintained constant. The necessary information about the basic weight of the material web is supplied over the conductor lines 54 and 56 from the basic weight measuring units 28, 28' and 26, 26'. These units are well known in the art and generally operate on the basis of radiation absorption. Corresponding control orders are transmitted over the line 58 to the applicator unit 22.
The liquor detector 40 supplies a measuring signal over the line 62 to the equalizer control unit 60 which transmits a control order over the line 64 to the motor 34 for the roller adjustment. The control units 50 and 60 may be connected to each other.
The roller 32 may be equipped with heating or cooling means; this is indicated by the coil 33. Furthermore, a steam hood 37 may be provided for introducing water steam into the space above and around the roller 32.
The raising-and-lowering motor 36 is arranged in such a manner that it can raise the roller 36 until a nip 41 having a defined thickness, is formed with the roller 32. Furthermore, a possibility (not shown) is foreseen to lower the roller 34 very rapidly by about 5 to 15 mm. This will be necessary when the additional thickness sensor 82--which may also be a contact-free one--detects a thicker spot or zone in the web 20. The thickness sensor 82 is connected by the line 34 to the control unit 60. The thicker spot in the web is then able to pass the equalizing device when the roller 34 has been lowered by that amount.
FIG. 2 shows in a very schematical manner a side elevation of another embodiment of the equalizing device. The two equalizing rollers 32 and 34, the latter being coated by a rubber layer 35, have their axes in a horizontal plane. The control motor 36 adjusts the thickness of the nip 41 by a horizontal displacement of the roller 34 so that no measures will be necessary to neutralize the weight of this roller.
Finally, FIG. 3 shows, also schematically, an embodiment of a roller-free equalizing slit. The slit is formed between an elongated stationary shaped part 32A and another shaped part 34A which is, however, pivotable around the axis 39. The operating surface of the shaped part 34A coming into contact with the material web 20, is coated with a rubber layer. All surfaces coming into contact with the web 20 are finally coated with an antifrictional layer. The equalizing slit is formed in the lower portion of the shaped parts 32A, 34A. For the control device 36, see the description above.
FIG. 4 shows schematically in side elevation a preferred applicator unit 22, namely the already mentioned metering roller application device.
The metering roller application device used here is another invention of the applicants and disclosed in all details in U.S. Pat. No. 4,672,705 incorporated herein by reference. Thus, the description of this apparatus need not fully be repeated.
A metering roller 72 is journalled for rotation in a trough 70 partially filled with liquor. The roller 72 is rotated in the direction indicated by the arrow. The material web 20 is slidingly passed over the upper surface of the metering roller 72; generally, the travelling speed of the web 20 is greater than the superficial speed of the metering roller 72.
Above the metering roller 72, a lowerable, drivable counter-roller 78 is provided which is directed to the arc of the roller 72 situated about 10 to 30 degrees from its summit, seen against the direction of web travel. This counter-roller, named tangential roller, is coated with rubber and can be adjusted by the motor 80 against and from the surface of the metering roller 72. Its purpose is to transfer the web 20 in supported condition onto the surface of the metering roller. The ductor blades 74 and 76 will keep the metering roller clean.
The motor 59 for a constant but adjustable rotational motion of the metering roller 72 whose superficial speed determines the amount of liquor to be applied in unit time, is connected by the line 58 to the control unit 50.
The system works in the following way:
The liquor amount applied to the web 20 is continuously monitored as a function of the difference of the data measured by the basic weight measuring units 28, 28' and 26, 26'. Suitable, known constructions of these units will allow a continuously averaging of the measured values over the width of the web in order to compensate for irregularities. Should the actual value of the application differ from the reference value set by the regulator 52, the control unit will correct the liquor applicator.
The material web 20 now containing the liquor, is guided around the upper roller 32 of the equalizing device through the nip 41 with the lower equalizing roller 34 and around the latter. The web then enters a drier 46, e.g. a tenter frame, and is finally wound on a roll 16.
The thickness of the roller nip 41 is adjusted by the control motor 36 to the predetermined value for the respective substrate and the amount of liquor therein, this value being determined by tests or experience and stored in a memory of the control device 60. This control device 60 will then have the thickness of the equalizing nip gradually reduced until first portions of liquor, squeezed out of the web by the continuously growing compression in the nip, will appear in front of the nip 41 and will not disappear immediately. This condition is detected by the liquid sensor 40 and transmitted to the control device 60 which will order the thickness of the nip 41 to be slightly increased. The short-lasting appearing and disappearing of emerging liquor portions indicate the optimum operation of the equalizing.
If no liquor portions will emerge in front of the nip 41, the liquor amount applied in the device 22 is too low to form a squeezable excess. This condition will be known before or transmitted by the application control unit 50 to the control device 60. In this case, motor 36 will receive an order to adjust the thickness of the nip 41 to an invariable value which is programmed and will be, e.g., 60% or 80% of the thickness of the material web.
For such applications, few tests will give empirically the optimum thickness of the nip.
Should viscous liquors be equalized or such liquors which do not have a good affinity t the substrate, a heating will be beneficial. For this reason the roller 32 is equipped with a heater. In order to prevent the evaporation of liquor solvent, the hood 37 allows to blow steam or a steam-air mixture onto the material web.
The apparatus and also the method of this invention may be modified in the frame defined by the claims. For example, the motor 36 which determines the position of the lower roller 34 of the equalizing device, may act on a reducing gear in order to obtain a still finer adjustment. Also, a dwell path may be provided between the applicator device 22 and the equalizing device 30.
The material of the rollers of the equalizing device should be resiliently elastic, one roller being harder than the other. Typically, a steel roller cooperates with a rubber roller. The surface of one roller may also be coated with a sponge rubber.
The apparatus of the invention may be used to perform the following finishing methods of textile material; the composition of the corresponding liquors is well known in the art:
Non-iron finishing
shrink-proof finishing
stiffening,
dyeing, particularly with pigments or reactive dyestuffs,
sizing, also of warp yarn layers,
softening,
hydrophobing
water drop proof finishing,
anti-fouling finishing,
soil-proof finishing,
oleophobing,
wrinkle-proof finishing,
lustering (chintz),
flame-proof finishing,
antistatic finishing,
felt-proof finishing,
anti-mite finishing,
decatizing,
effect finishing.
Liquors may be used which are aqueous, aqueous/organic or exclusively organic ones.
The foregoing description of preferred embodiments is not to be considered as limiting the invention or as to mention all possibilities, variants and modifications thereof. | A process and an apparatus for the continuous and controlled application of liquor on an absorptive, compressible material web such as textile webs, warp yarn layers or vleeces. One or more liquors are applied in amounts being comprised between the values of water retention capacity and saturation. The liquor containing web is passed through an equalizing device wherein the web is drawn through an equalizing nip or slit whose thickness is adjustable and smaller than the thickness of the incoming, liquor containing material web. The equalizing may be effected in the nip of two rollers. The liquor concentration in the web before and after the equalizing is statistically the same. | 3 |
BACKGROUND
[0001] The present invention relates generally to operations performed and equipment utilized in conjunction with a subsea pipeline and, in particular, to subsea pigging and hydrostatic testing operations.
[0002] After fabrication, a pipeline must be pre-commissioned through a process that typically involves cleaning, filling the pipeline with water, and hydrostatically testing the pipeline to prove its integrity and confirm the pipeline has no leaks. In the case of a subsea pipeline, the pressure difference between the interior of the pipe and the surrounding sea can be used to fill the pipeline or assist in the pigging process by allowing water from the sea to enter the pipeline.
[0003] However, for many reasons, simply opening a valve to direct water into the pipe is not sufficient to fill the pipeline or drive a pig through the pipeline, including because the flow rate must be controlled and simply utilizing the pressure difference will not obtain a complete filling of the pipeline. Initially in a flooding operation, the driving differential pressure is at a maximum, where the pipeline could flood too quickly if the flow rate is not controlled. As the flooding operation continues and the pipeline becomes progressively filled, the driving differential pressure decreases until the pressures substantially equalize and the differential pressure is no longer sufficient to fill the pipeline. At this point, intervention is required to complete the flooding operation.
[0004] The subsea pre-commissioning process typically involves a ship positioned on the spot and containing equipment to facilitate the pre-commissioning operation. Units known as subsea pigging units or hydrotesting units have been used to complete the pipeline filling operation and perform the hydrostatic testing operation on the sea floor. These subsea pigging and hydrotesting units are often powered from and controlled by a surface vessel.
FIGURES
[0005] Some specific exemplary embodiments of the disclosure may be understood by referring, in part, to the following description and the accompanying drawings.
[0006] FIG. 1 illustrates an example diagram of system components that incorporates one or more principles of the present disclosure, according to aspects of the present disclosure.
[0007] FIG. 2 illustrates an example multifunction unit assembly, according to aspects of the present disclosure
[0008] FIG. 3 illustrates an example graph of differential driving pressure during a flooding operation, according to aspects of the present disclosure.
[0009] While embodiments of this disclosure have been depicted and described and are defined by reference to exemplary embodiments of the disclosure, such references do not imply a limitation on the disclosure, and no such limitation is to be inferred. The subject matter disclosed is capable of considerable modification, alteration, and equivalents in form and function, as will occur to those skilled in the pertinent art and having the benefit of this disclosure. The depicted and described embodiments of this disclosure are examples only, and not exhaustive of the scope of the disclosure.
DETAILED DESCRIPTION
[0010] The present invention relates generally to operations performed and equipment utilized in conjunction with a subsea pipeline and, in particular, to subsea pigging and hydrostatic testing operations.
[0011] Illustrative embodiments of the present disclosure are described in detail herein. In the interest of clarity, not all features of an actual implementation may be described in this specification. It will of course be appreciated that in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the specific implementation goals, which will vary from one implementation to another.
[0012] Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of the present disclosure.
[0013] The terms “couple” or “couples” as used herein are intended to mean either an indirect or direct connection. Thus, if a first device couples to a second device, that connection may be through a direct connection, or through an indirect mechanical or electrical connection via other devices and connections. The term “uphole” as used herein means along the drillstring or the hole from the distal end towards the surface, and “downhole” as used herein means along the drillstring or the hole from the surface towards the distal end.
[0014] To facilitate a better understanding of the present disclosure, the following examples of certain embodiments are given. In no way should the following examples be read to limit, or define, the scope of the disclosure. Embodiments of the present disclosure may be applicable to rigid steel pipelines, rigid steel connections spools, composite flexible flowlines, composite flexible connection jumpers, pig launchers, pig receivers, connection hub end caps, or other pipeline features in any type of subsea configuration. Embodiments may be applicable to any subsea pipeline system including natural resource production transport, water injection, and service chemical transport. Embodiments described below with respect to one implementation are not intended to be limiting.
[0015] Referring to FIG. 1 , an example schematic diagram of a remote subsea unit 100 is shown. In certain embodiments, the remote subsea unit 100 may include an inlet 110 connected to a pipeline 130 via subsea unit conduit 120 . In certain embodiments, fluid entering the inlet 110 may be directed through at least one filter 170 able to purify sea water entering the inlet 110 to a required standard. A multifunction unit 140 may be located in the subsea unit conduit 120 such that water flowing from the inlet 110 and through the subsea unit conduit 120 may be directed through the multifunction unit 140 . In certain embodiments, the remote subsea unit 100 may include a battery 150 electrically connected to the multifunction unit 140 . In certain embodiments, the battery 150 may be any of a deep charge lead acid battery, lithium ion battery, nickle metal hydride battery, lithium air battery, and lithium polymer battery, or any other battery suitable for subsea operations.
[0016] In certain embodiments, the remote subsea unit 100 may include at least one chemical storage tank 160 configured to inject a desired additive chemical to the fluid in the subsea unit conduit 120 . In an embodiment, a chemical injection pump 165 may be in fluid communication with the at least one chemical storage tank 160 and configured to assist flow of additive chemicals into the subsea unit conduit 120 . The chemical injection pump 165 may control the flow rate of additive chemicals to be proportional to the water flow rate. In an embodiment, the remote subsea unit 100 may include a communications link 180 . The communications link 180 may allow communication between the remote subsea unit 100 and an operator and allow the operator to control the remote subsea unit 100 via a control and communications device 185 . The battery 150 may be electrically connected to the control and communication device 185 and configured to provide electrical power to the control and communication device 185 .
[0017] Referring now to FIG. 2 , an example assembly view of an embodiment of the multifunction unit 140 is shown, according to aspects of the present disclosure. The multifunction unit 140 may include a boost pump 210 coupled to a motor generator 220 via a gearbox 230 . The motor generator 220 may be located in a motor generator housing 225 . In certain embodiments, the motor generator 220 may be an electric motor generator. In further embodiments, the motor generator 220 may be a DC electric motor generator.
[0018] The multifunction unit 140 may be configured to operate in at least two modes: a generator mode and a motor mode. In the generator mode, fluid flowing through the boost pump 210 may cause the boost pump to rotate. The rotation of the boost pump 210 , via the gearbox 230 , drives the motor generator 220 , generating electricity that may be directed to a battery 250 connected to the motor generator 220 to store generated electrical energy.
[0019] When the multifunction unit 140 is in the motor mode, the motor generator 220 may drive the boost pump 210 to drive the boost pump 210 via the gearbox 230 , directing fluid through the subsea unit conduct 120 . In certain embodiments, once the flooding operation reaches a predetermined completion point, the multifunction unit 140 may be switched from the generator mode to the motor mode. Once in the motor mode, the boost pump 210 may direct fluid to the pipeline 130 to complete flooding of the pipeline 130 . In certain embodiments, the predetermined completion point may be set by comparing the difference between the seabed pressure and the inner pipeline pressure. Referring to FIG. 3 , an example chart of the differential driving pressure between the seabed and the pipeline is shown as a function of percentage of pipeline flooded during the course of a flooding operation. In the example embodiment shown, the differential driving pressure is positive at the beginning of the flooding operation, where the seabed pressure is greater than the inner pipeline pressure, and decreases slowly the flooding operation progresses. Once the pipeline is substantially flooded, the differential driving pressure decreases sharply until it becomes negative. When the differential driving pressure and/or the flow rate decreases below a desired point, the multifunction unit 140 may switch to motor mode and drive the boost pump 210 to direct fluid to the pipeline 130 to complete the pipeline flooding operation. In certain embodiments, the multifunction unit 140 may be switched to motor mode at the point when the driving pressure becomes negative.
[0020] Referring again to FIG. 1 , in certain embodiments, the remote subsea unit 100 may include a variable choke 175 configured to control or adjust the flow of fluid into the pipeline 130 . In certain embodiments, the variable choke 175 may control the flow rate through a programmable logic controller (PLC) feedback sensor to actuate a choke valve in response to changes in the flow rate. In certain embodiments, the variable choke 175 may adjust the flow rate using a dynamic braking and feedback PLC circuit. In certain embodiments, the remote subsea unit 100 may include a pipeline isolation valve 135 disposed between the subsea unit conduit 120 and the pipeline 130 .
[0021] The remote subsea unit 100 may include pipeline flooding valves 142 , 144 . The pipeline flooding valves 142 , 144 may be remotely operated via the control and communications unit 185 and communications link 180 and may be electrically powered by the battery 150 . In certain embodiments, an operator may remotely open the pipeline flooding valves 142 , 144 to begin flooding operations. In certain embodiments, remote operation and control of the remote subsea unit 100 may be accomplished through low frequency signals, between about 3-300 Hz and acoustic telemetry. A remotely operated vehicle may also be used to operate the pipeline flooding valves 142 , 144 . In certain embodiments, after the pipeline flooding operation is completed, the pipeline flooding valves 142 , 144 may be closed.
[0022] In certain embodiments, the remote subsea unit may include a hydrostatic testing pump 190 and hydrostatic testing valve 195 . The hydrostatic testing pump 190 and hydrostatic testing valve 195 may be electrically connected to the control and communications device 185 to allow remote operation of the hydrostatic testing pump 190 and hydrostatic testing valve 195 . The hydrostatic testing pump 190 and hydrostatic testing valve may be electrically powered by the battery 150 . In certain embodiments, the remote subsea unit 100 may be used to hydrostatically test the flooded pipeline 130 by closing the pipeline flooding valves 142 , 144 , opening the pipeline testing valve 190 , and opening the pipeline isolation valve 175 . In certain embodiments, the hydrostatic testing process may be initiated automatically after completion of the flooding operation. In certain embodiments, the remote subsea unit 100 may be used to drive a pig through the pipeline 130 .
[0023] The remote subsea unit 100 may allow initiation and completion of a remote flooding operation without requiring a surface or outside power source. The multifunction unit 140 may generate electrical power using the flow of water caused by the differential driving pressure and store the generated electrical power in a battery 150 . The electrical power generated by the multifunction unit 140 may be greater than the electrical power required by the multifunction unit 140 in motor mode to finish the pipeline flooding operation. Thus, the battery 150 may be used to power other various aspects and operations of the remote subsea unit 100 , such as electro chlorination, UV sterilization, logger functions, and remote telemetry.
[0024] Therefore, the present disclosure is well adapted to attain the ends and advantages mentioned as well as those that are inherent therein. The particular embodiments disclosed above are illustrative only, as the present disclosure may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular illustrative embodiments disclosed above may be altered or modified and all such variations are considered within the scope and spirit of the present disclosure. Also, the terms in the claims have their plain, ordinary meaning unless otherwise explicitly and clearly defined by the patentee. The indefinite articles “a” or “an,” as used in the claims, are defined herein to mean one or more than one of the element that it introduces. | A subsea pipeline apparatus is disclosed, including a multifunction unit, an inlet to direct fluid toward the multifunction unit, and energy storage unit connected to the multifunction unit, and an outlet configured to receive fluid passed through the multifunction unit. The multifuntion unit may operate in at least two modes: a generator mode, allowing the generation of energy from the flow of fluid, and a motor mode, allowing the fluid to be forced to the outlet and into the subsea pipeline. | 6 |
BACKGROUND OF THE INVENTION
This invention relates to rapid set latexes and rapid set foamed articles prepared therefrom. Foamed polymeric materials, also known as cellular materials, have an apparent density with respect to the polymeric material that is substantially decreased by the presence of numerous gaseous pockets (i.e., cells) disposed throughout its mass. If the cells are interconnected, the material is considered open-celled; if the cells are discrete, the material is considered closed-celled.
Cellular materials are typically prepared by dispersing gas bubbles throughout a fluid polymer to create a froth, then preserving the resultant state to form the cellular material. Bubble initiation can be promoted in a number of ways including supersaturating a polymer solution with a gas at high temperatures; incorporating low boiling liquids into the system as blowing agents and forcing the liquids into the gas phase by increasing the temperature or decreasing the pressure; and incorporating blowing agents that thermally decompose to form a gas. Unfortunately, the polymer typically needs to be dissolved in an organic solvent, the bubble initiation generally requires temperature or pressure control or both, and in many instances, the methods require environmentally undesirable blowing agents (for example, CFCs).
In view of the deficiencies in the art, it would be advantageous to prepare a foamed structure by a process that did not require ancillary solvents or environmentally undesirable blowing agents, and that could be carried out effectively at ambient temperatures and pressures.
SUMMARY OF THE INVENTION
The present invention addresses a need in the art by providing a simple, fast, and environmentally friendly method for preparing a cellular article from a latex. Accordingly, in one aspect, the present invention is a process for preparing a cellular article comprising the steps of: a) frothing a latex that contains a dispersed polymer having pendant cationic groups or adsorbing cationic molecules or both, and pendant acid groups; and b) rendering the frothed latex sufficiently basic to make the cellular article.
In a second aspect, the present invention is a cellular article that comprises a coacervate of a polymer having pendant cationic groups or adsorbing cationic groups or both, and pendant acid groups.
In a third aspect, the present invention is a stable aqueous dispersion that contains a dispersed polymer having pendant weak cationic groups or adsorbing cationic groups or both, and pendant weak acid groups.
The cellular article of the present invention is advantageously prepared at ambient temperatures and pressures, and in the absence of organic solvents or CFCs. The cellular article can be prepared relatively quickly from the frothed dispersion as a result of the rapidity with which the solution or dispersion sets when contacted with a sufficient amount of base. This rapid-setting property prevents the collapse of the cellular article during its preparation and also prevents deformation of the shape of the cellular article, for example, by slumping.
DETAILED DESCRIPTION OF THE INVENTION
The cellular article of the present invention is prepared by frothing a latex containing a polymer having pendant or adsorbing cationic groups and pendant acid groups, and rendering the frothed dispersion sufficiently basic to form the cellular latex article. As used herein, the term "pendant" is used to refer to a group that is chemically bound to the polymer backbone. The term "adsorbing cationic molecule" is used herein to refer to a molecule that contains a cationic group that is capable of physically adsorbing to a latex particle. The polymer having pendant cationic groups and pendant acid groups can be prepared by polymerizing a polymerizable cationic monomer and an acid monomer, more preferably by polymerizing a polymerizable strong cationic monomer and a weak acid monomer. A polymer that is prepared in such a manner is said to contain structural units formed from the polymerization of a polymerizable cationic monomer and a polymerizable acid monomer, more preferably a polymerizable weak acid monomer.
It is also possible to prepare a polymer that has pendant strong acid groups such as sulfonic acid groups, and weak cation groups such as protonated primary, secondary, or tertiary amines, so long as the pH of the latex is sufficiently low such that the net charge of the latex particles is cationic and the latex is stable. Furthermore, it is possible to prepare a polymer that has pendant weak acid groups and pendant weak cationic groups, again, provided that the pH of the latex is sufficiently low such that the net charge of the latex particles is cationic and the latex is stable.
As used herein, the term "sufficiently basic" refers to sufficiency of amount of base as well as base strength. The word "latex" refers to a stable aqueous dispersion and can be synthetic or artificial. The term "polymerizable weak acid monomer" refers to a monomer that contains ethylenic unsaturation and an anionic group having a charge that depends on pH. The term "structural units formed from the polymerization of . . . " is illustrated by the following example: ##STR1##
The polymer also preferably includes structural units formed from the polymerization of a polymerizable non-interfering monomer. The term "polymerizable non-interfering monomer" is used herein to refer to a monomer that does not adversely affect the formation of the cellular structure.
Polymerizable weak acid monomers that are suitable for the preparation of the latex used to prepare the cellular article include ethylenically unsaturated compounds having carboxylic acid, phenolic, thiophenolic, or phosphinyl functionality. Preferred polymerizable weak acid monomers include acrylic acid, methacrylic acid, itaconic acid, β-carboxyethyl acrylate (usually as a mixture of acrylic acid oligomers), vinylbenzoic acid, and 2-propenoic acid: 2-methyl-, (hydroxyphosphinyl) methyl ester. Acrylic acid and methacrylic acid are more preferred weak acid monomers. Thus, preferred pendant acid groups are carboxylic acid groups.
Suitable polymerizable cationic monomers include polymerizable strong cationic monomers and polymerizable weak cationic monomers. As used herein, the term "polymerizable strong cationic monomer" refers to a monomer that contains ethylenic unsaturation and a cationic group having a charge that is independent of pH. The polymerizable cationic monomer is associated with a counterion, which may be, for example, halide such as chloride, bromide, or iodide, as well as nitrate, or methylsulfate. The term "polymerizable weak cationic monomer" refers to a monomer that contains ethylenic unsaturation and a cationic group having a charge that is dependent on pH.
Polymerizable strong cationic monomers include salts of ethylenically unsaturated compounds having quaternary ammonium, sulfonium, cyclic sulfonium, and phosphonium functionality, with salts of ethylenically unsaturated quaternary ammonium salts being preferred. Examples of suitable monomers having quaternary ammonium functionality include ethylenically unsaturated trialkylammonium salts such as vinylbenzyl trialkylammonium chloride or bromide; such as vinylbenzyl trimethylammonium chloride or a polymerizable surfactant such as vinylbenzyl dimethyloctadecylammonium chloride; trialkylammoniumalkyl acrylates or methacrylates such as 2-((methacryloyloxy)ethyl)-trimethylammonium chloride and N,N-diethyl-N-methyl-2-((1-oxo-2-propenyl)oxy) ethanaminium methyl sulfate (Chem. Abstracts Reg. No. 45076-54-8); and trialkylammoniumalkyl acrylamides such as N,N,N-trimethyl-3-((2-methyl-1-oxo-2-propenyl)amino)-1-propanaminium chloride (Chem. Abstracts Reg. No. 51441-64-6) and N,N-dimethyl-N-(3-((2-methyl-1-oxo-2-propenyl)amino)propyl]-benzenemethaminium chloride (Chem. Abstracts Reg. No. 122988-32-3). A preferred polymerizable quaternary ammonium salt is 2-((methacryloyloxy)ethyl])-trimethylammonium chloride.
Examples of polymerizable unsaturated sulfonium salts include dialkylsulfonium salts such as [4-ethoxy-3-(ethoxycarbonyl)-2-methylene-4-oxobutyl]dimethylsulfonium bromide (Chem. Abstracts Reg. No. 63810-34-4); and vinylbenzylvinylbenzyldialkylsulfonium salts such as vinylbenzyldimethylsulfonium chloride. Examples of polymerizable cyclic sulfonium salts include 1-[4-[(ethenylphenyl)methoxy]phenyl]tetrahydro-2H-thiopyranium chloride (Chem. Abstracts Reg. No. 93926-67-1); and vinylbenzyltetrahydrothio-phenonium chloride, which can be prepared by the reaction of vinylbenzyl chloride with tetrahydrothiophene.
Examples of polymerizable phosphonium salts include 2-methacryloxyethyltri-C 1 -C 20 -alkyl-, aralkyl-, or aryl-phosphonium salts such as 2-methacryloxyethyltri-n-octadecylphosphonium halide (Chem. Abstracts Reg. No. 166740-88-1); tri-C 1 -C 18 -alkyl-, aralkyl-, or aryl-vinylbenzylphosphonium salts such as trioctyl-3-vinylbenzylphosphonium chloride, trioctyl-4-vinylbenzylphosphonium chloride (Chem. Abstracts Reg. No. 15138-12-4), tributyl-3-vinylbenzylphosphonium chloride, tributyl-4-vinylbenzylphosphonium chloride (Chem. Abstracts Reg. No. 149186-03-8), triphenyl-3-vinylbenzylphosphonium chloride, and triphenyl-4-vinylbenzylphosphonium chloride (Chem. Abstracts Reg. No. 145425-78-1); C 3 -C 18 -alkenyltrialkyl-, aralkyl-, or aryl-phosphonium salts such as 7-octenyltriphenylphosphonium bromide (Chem. Abstracts Reg. No. 8266745-6); and tris(hydroxymethyl)(1-hydroxy-2-propenyl)phosphonium salts (Chem. Abstracts Reg. No. 7308248-1).
It is also possible to prepare the polymer by polymerizing a monomer that contains both a weak acid group and a cationic group. An example of such a monomer is N-(4-carboxy)benzyl-N,N-dimethyl-2-[(2-methyl-1-oxo-2-propenyl)-oxy] ethanaminium chloride.
It is further possible to prepare a polymer having pendant strong cationic groups and weak acid groups by adding strong cationic functionality to an already prepared polymer. For example, a polymerizable monomer having a weak acid group can be copolymerized with a polymerizable non-interfering monomer containing an electrophilic group, such as a vinylbenzyl halide or a glycidyl methacrylate, to form a polymer having a weak acid group and an electrophilic group. This polymer can then be post-reacted with a nucleophile such as a tertiary amine or a dialkyl sulfide, which can displace the halide group or oxirane groups and form a benzylonium salt as illustrated: ##STR2## where A is a pendant weak acid group; Ar is an aromatic group, preferably a phenyl group; L is a leaving group, preferably a halide group, more preferably a chloride group; and Nu is preferably a dialkyl sulfide such as dimethyl sulfide and diethyl sulfide; a cyclic sulfide such as tetrahydrothiophene; or a tertiary amine such as trimethyl amine, triethyl amine, tripropyl amine, tributyl amine, and triethanol amine.
In another example of adding strong cationic functionality to an already prepared polymer, a polymer backbone that contains pendant acid groups and a tertiary amine or a sulfide can be post-reacted with a suitable alkylating reagent such as an alkyl halide to form a polymer that contains acid groups and strong cationic groups: ##STR3## where RL is an alkylating reagent.
Suitable polymerizable weak cationic monomers include ethylenically unsaturated protonated primary, secondary, and tertiary amines such as salts of dialkylaminoalkylacrylates, dialkylaminoalkylmethacrylates, aminoalkylacrylates, aminoalkylmethacrylates, aminoacrylates, and aminomethacrylates. Examples of polymerizable weak cationic monomers include the hydrochloride salts of dimethylaminoethylmethacrylate and aminoethylmethacrylate.
Examples of non-interfering polymerizable monomers include acrylates such as methyl acrylate, ethyl acrylate, butyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, glycidyl acrylate, and allyl acrylate; methacrylates such as methyl methacrylate, ethyl methacrylate, butyl methacrylate, allyl methacrylate, glycidyl methacrylate, 2-hydroxyethyl methacrylate, and 2-hydroxypropyl methacrylate; and C 1 -C 4 alkyl- or alkenyl-substituted styrenics, preferably styrene, α-methylstyrene, vinyltoluene, and vinylbenzyl chloride. Other examples of non-interfering species include C 3 -C 18 -perfluoroalkyl methacrylates such as 2-(perfluorooctyl)ethyl methacrylate; C 3 -C 18 -perfluoroalkyl acrylates such as 2-[ethyl[(heptadecafluorooctyl)-sulfonyl]amino]ethyl 2-propenoate; and C 3 -C 18 -perfluoro-alkyl vinylbenzenes. (See U.S. Pat. No. 4,929,666, column 4, lines 54 to 68, and column 5, lines 1 to 30.)
The latex may contain adsorbing cationic molecules as an alternative to, or in addition to pendant cationic groups. Adsorption of a molecule onto the latex particle can be determined by the separation of the particles from the serum phase, for example, by sedimentation of the latex particles, followed by analysis of the serum phase for the molecules. Adsorption is indicated by a serum phase concentration of the molecules that is less than that which was added to the latex. These adsorbed groups can be removed by extraction, for example, by dialysis or addition of a suitable solvent.
The adsorbing cationic molecules, which need not be polymerizable, contain either a strong cationic group or a weak cationic group and a hydrophobic portion. If the molecules are not polymerizable, the hydrophobic portion is typically a branched or linear alkyl group having a chain length of preferably not less than 10 carbon atoms, more preferably not less than 12, and most preferably not less than 16. Examples of preferred adsorbing cationic molecules include long chain alkyl quaternary ammonium salts such as trimethyloctadecyl ammonium chloride, trimethylhexadecyl ammonium chloride, and trimethyldodecyl ammonium chloride.
The ratio of the pendant acid groups to the pendant cationic groups or adsorbing cationic molecules is application dependent, but is generally in the range of about 1:10 to about 5:1. The ratio of the structural units formed from the polymerization of the polymerizable non-interfering monomer to the weak acid groups and the cationic groups is application dependent, but is preferably not less than about 70:30, more preferably not less than about 80:20, more preferably not less than about 90:10, and most preferably not less than about 94:6; and preferably not greater than about 99.5:0.5, more preferably not greater than about 99:1, and most preferably not greater than about 98:2.
In general, the higher the latex solids content, the lower the concentration of the total ionic species that is required to form the quick-set foam. The solids content of the latex in the formulation to be frothed is application dependent, but preferably not less than 10, more preferably not less than 20, and most preferably not less than 30 weight percent, and preferably not more than 60, more preferably not more than 55, and most preferably not more than 50 weight percent.
The latex can be prepared by any suitable means, and is advantageously prepared by the steps of: 1) preparing a seed latex; 2) diluting the seed latex with water; 3) contacting the diluted solution with a radical initiator, a polymerizable non-interfering monomer, a polymerizable weak acid monomer, and a polymerizable or non-polymerizable cationic monomer; and 4) polymerizing the solution from step 3 under such conditions to form a latex having non-interfering groups, pendant cationic groups or adsorbing cationic molecules, and pendant weak acid groups.
The seed latex is preferably prepared by emulsion polymerization in a batch process using a cationic surfactant. The seed latex acts as a locus of polymerization for subsequent monomer addition, so that the formation of new particles is minimized and greater uniformity in the distribution of particle size in the final product is achieved. Thus, the monomer or monomers used to prepare the seed latex are chosen to form particles that have an affinity for the monomers subsequently added, so that polymerization occurs preferentially in or on the seed latex particles. The extent to which the seed latex is diluted in step 2 is a function of the desired particle size and the percent solids in the final latex, and can be readily determined by one of ordinary skill in the art.
It is also possible to prepare a latex from a preformed polymer. The preformed polymer can be dissolved in a suitable solvent, then dispersed in water by any suitable method. The solvent can then be removed and the solids content adjusted to form a so-called artificial latex.
The latex can be frothed and sequentially or concomitantly rendered sufficiently basic to form a coacervated cellular article by a variety of methods. As used herein, "coacervation" refers to the setting of an article by a pH shift. For example, a dispersing fluid can be entrained and dispersed under shear into a mixture of the latex and the frothing agent to form the frothed latex, which can then be converted to the cellular material (that is, set) by adding base thereto. Dispersing fluids include gases and volatile liquids known in the art. Preferred dispersing fluids include air, nitrogen, carbon dioxide, argon, and helium.
The base may be added as a gas, a liquid, a solid, or a dispersion. Suitable bases include, but are not restricted to, amines, ammonia, alkali metal and alkaline earth metal phosphates, carbonates, bicarbonates, oxides, and hydroxides. Preferred bases include calcium carbonate, calcium oxide, calcium hydroxide, sodium hydroxide, potassium hydroxide, magnesium hydroxide, sodium bicarbonate, sodium carbonate, and ammonia (aqueous or gaseous); as well as basic rheology enhancing filler materials such as Portland cement, aluminous cement, and inorganic mortar. (In general, both basic and non-basic filler materials may be added to increase density, load bearing, and sound attenuation, and in some instances, reduce costs of the cellular material.)
Alkali metal hydroxides are preferably added as solutions in water, while alkaline earth metal hydroxides, calcium carbonate, Portland cement, aluminous cement, and inorganic mortar are preferably added as aqueous dispersions, more preferably in the presence of a cationic surfactant.
It is also possible to render the latex basic by removing acid. For example, if the counterion associated with the cation is bicarbonate and the pH of the latex is lowered by the presence of CO 2 , the latex can be rendered basic by loss of CO 2 .
The frothing agent is preferably cationic or non-ionic, or a combination thereof, more preferably cationic. The frothing agent may be inherently present in the latex (that is, the latex may be prepared in the presence of a cationic dispersant that acts as a frothing agent), or may be added to the latex in a separate step. The selection of a frothing agent is generally dictated by the presence and type of filler material in the formulation used to prepare the foam. Examples of suitable frothing agents include FLUORAD™ FC-135 fluorinated alkyl quaternary ammonium cationic surfactant (a trademark of 3M Corp.), KEMAMINE™ Q9973-C soyatrimethyl ammonium chloride (a trademark of Witco Corp.), ARQUAD™ 18/50 steartrimonium chloride (CAS 112-03-8, a trademark of Akzo Chemical Co.), DUOMEEN™ TDO (N-tallow-1,3-propandiamine dioleate, CAS 61791-53-5, a trademark of Akzo Chemical Co.), ETHOMEEN™ T15 (PEG-5 tallow amine, CAS 61791-26-2, a trademark of Akzo Chemical Co.), a blend of ETHOMEEN™ T15 and DUOMEEN™ TDO, and a blend of ARQUAD™ 18/50 steartrimonium chloride and DUOMEEN™ TDO. Other examples of cationic frothing agents include those useful as adsorbing cationic molecules, described hereinabove.
The amount of frothing agent that is used tends to depend on factors such as the amount and type of foam desired, the type of frothing agent used, and the means used for preparing the foam. Preferably, the amount of frothing agent used is not greater than about 10 percent, more preferably not greater than about 5 percent, most preferably not greater than about 3 weight percent based on the weight of the latex and the surfactant, and preferably not less than about 0.1 weight percent, more preferably not less than about 0.5 weight percent.
The latex may also be combined with an aqueous dispersion of a frothing agent and a substantially non-basic or amphoteric filler material under conditions of stirring, and in the presence of a dispersing fluid, to form the frothed latex. In this instance, a sufficient amount of a suitable base can be combined with the frothed latex to convert it to the cellular material. Examples of non-basic fillers include carbon, clay, talc, titanium oxide, barium sulfate, stannous octoate, mica, glass, and Al(OH) 3 .
It is also possible to form a foamed article by introducing a blowing agent into the rapid set latex formulation, then expanding the resulting formulation by methods well known in the art to from a cellular material. The blowing agent may be present with or without the frothing agent.
Base need not be added to the frothed latex to render the latex basic. For example, the latex can be rendered basic by frothing in the presence of a suitable dispersing fluid a latex that contains a bicarbonate ion associated with the strong cation group. The pH of the latex is raised sufficiently to form the latex foam as a result of the loss of CO 2 . Thus, the latex is rendered basic by the loss of an acid.
To obtain the bicarbonate salt, the latex can be ion exchanged with bicarbonate ion, by first saturating the latex under pressure with carbon dioxide, either as dry ice or as a gas, then contacting the CO 2 -saturated latex with an ion exchange resin that contains bicarbonate functionality such as DOWEX™ Monosphere 550A anion exchange resin (a trademark of The Dow Chemical Company) in the bicarbonate form. The pH of the latex is sufficiently low to render the polymer stable in the continuous phase, preferably lower than the pK a of the weak acid group, more preferably not greater than 5, and most preferably not greater than 4.
The cellular article of the present invention is useful in applications that are typical of cellular articles, including applications that require sound deadening, light weight, fluid absorption, and insulation.
The following examples are for illustrative purposes only and are not intended to limit the scope of this invention.
EXAMPLE 1
Rapid Set Foam Prepared Using Powdered Alkaline Solid
The stable aqueous dispersion was prepared in a two-step process. First, a cationic surfactant stabilized polystyrene seed latex was prepared using a batch process. Next, a portion of the seed latex was used in a continuous addition process to prepare a second latex containing a carboxylic acid and a quaternary ammonium functional monomer.
The cationic latex seed was prepared in the following manner. To a 1-liter, 3-neck, glass reaction flask equipped with a nitrogen inlet, a reflux condenser with a nitrogen outlet, and a mechanical stirrer was added with stirring styrene (100 g), 40 g ARQUAD™ 18-50 octadecyltrimethylammonium chloride surfactant (a trademark of Akzo Nobel, 20 g active), hydrogen peroxide (3.3 g, 1.0 g active), water (200 g), and FeSO 4 .7H 2 O solution (0.25 g of a 0.25 weight percent solution of aqueous FeCl 3 ). The flask was heated to 70° C. over 2 hours with stirring under nitrogen, after which the stirring was stopped and the heating source removed. The latex seed was allowed to sit overnight in the flask. The result was an opaque, high viscosity dispersion with 35.8 percent solids. The particle size was 407 Å (mean value) and 393 Å (median value).
The foam-forming latex was prepared from the cationic seed latex using a continuous addition polymerization method. Syringe pumps were used as the continuous addition control means. To a 2-liter, 3-neck, glass reaction flask equipped with a nitrogen inlet, a reflux condenser with a nitrogen outlet, and a mechanical stirrer was added, with stirring, water (452.3 g) and the cationic seed latex (8.8 g). The flask was heated to 60° C. Table 1 shows the solutions that were prepared for continuous addition.
TABLE 1______________________________________Reagents used to Prepare the LatexStream Component Amount______________________________________1 Butyl Acrylate 176 g Methyl Methacrylate 124 g Methacrylic Acid 5.3 g2 M-QUAT ™ .sup.a 17.3 g (12.8 g active)3 t-Butylhydroperoxide 1.8 g (1.3 g active)4 Sodium Formaldehyde Sulfoxylate 0.96 g in 10 ml water______________________________________ .sup.a 2((methacryloyloxy)ethyl) trimethylammonium chloride obtained as a 74 percent aqueous solution from Bimax Inc., 717 Chesapeake Ave., Baltimore, MD 21225
The components from the four streams were added over the first four hours of After completion of addition, polymerization was continued at 60° C. for 0.5 hour. The resulting latex was filtered and found to have a solids content of 37.0 percent. Table 2 shows the composition of the latex.
TABLE 2______________________________________Composition of the Latex Molecular Weight Mole WeightMonomer Percent Percent (g/mol)______________________________________Butyl Acrylate 55.3 50.2 128.1Methyl Methacrylate 39.0 45.3 100.1Methacrylic Acid 1.7 2.3 86.1M-QUAT 4.0 2.3 207.7______________________________________ The particle size was 1550 Å (mean) and 1450 Å (median).
To a portion of the latex (19.0 g) was added Dow Corning 193 dimethicone copolyol nonionic silicone surfactant (0.35 g) and FLUORAD™ FC-135 fluorinated alkyl quaternary ammonium iodide cationic surfactant (a trademark of 3M Corporation, 0.02 g, 25 weight percent). The mixture is stirred to produce a froth, whereupon dry, ceramic wall cement (10 g, obtained as a powder from Color Tile Man, Inc.) was added using high speed stirring over 30 seconds. After about 2 minutes, a semisolid cellular article (i.e., a foam) having less than 1-mm diameter cells was obtained.
EXAMPLE 2
Rapid Set Foam Using a Dispersed Alkaline Solid
A portion of the latex prepared as described in Example 1 (25.7 g) was added to a container sequentially with a cationic fluorocarbon solution (0.18 g, containing 6.0 weight percent FLUORAD FC-135 fluorinated alkyl quaternary ammonium iodide cationic surfactant, 69.9 weight percent water, and 26.1 weight percent isopropanol). A calcium carbonate dispersion (93.35 g, type HOKMH from Hustadmarmor A/S, N-6440 Elnesvagen, Norway) was weighed out in a separate container. A Cowles-type mixing blade was inserted in the mixture of the latex and fluorocarbon solution, and then rotated at 3000 rpm. The HOKMH dispersion was then added in one portion to the rapidly stirred mixture (addition time of less than 5 seconds). The mixing was stopped about 1 minute after the addition of HOKMH dispersion. The resultant cellular material was a semisolid article that could be easily spread with a spatula. After drying at room temperature this cellular material gave a hard, porous structure with the largest pores being about 250 microns. The weight-to-weight ratio of the calcium carbonate to the polymer was about 6.2:1.
EXAMPLE 3
Rapid Set Foam Prepared by Addition of an Alkaline Liquid
A latex was prepared as described in Example 1, except that methacrylic acid was replaced with an equimolar amount of β-carboxyethyl acrylate. A portion of this latex (26.04 g) was placed in a bottle along with a dispersant (0.59 g), the composition of which is shown in Table 3. In a separate bottle was combined deionized water (10.24 g) and sodium bicarbonate (0.27 g). The latex and the dispersant were frothed by bubbling nitrogen up from the base of the bottle, and mixed at 1200 rpm for 30 seconds. The mixing rate was increased to 2600 rpm and maintained at that speed for 1 minute before the bicarbonate solution was added in one portion to the frothed latex. Mixing was continued for about 10 seconds, at which time the froth had begun to set.
TABLE 3______________________________________Composition of the DispersantMaterial Amount (g)______________________________________DUOMEEN ™ TDO 10.00ETHOMEEN ™ 0/15 20.00Deionized water 120.00______________________________________
EXAMPLE 4
Preparation of a Rapid Set Foam Using Non-polymerizable Cation
The latex was prepared in the same way as the latex used in Example 1, except that an equimolar concentration of ARQUAD™ 18-50 surfactant was used instead of M-QUAT™ monomer. A portion of this latex (10.01 g) was placed into a bottle along with KEMAMINE™ Q9973-C (0.11 g). The latex and dispersant were mixed by agitating at 500 rpm for 1 minute. The dispersion was then frothed by mixing at 1000 rpm for 2 minutes, increasing the speed to 1500 rpm for 30 seconds, then returning the mixing speed to 1000 rpm. A portion of Mg(OH) 2 (1.016 g) was then added to the froth and agitation was continued for 15 seconds, at which point the froth was completely set.
EXAMPLE 5
Preparation of a Rapid Set Foam Using a Latex Containing Strong Anionic Charges plus Weak Cationic Charges
A foam-forming latex was prepared in a two-step process similar to that in Example 1. First, a cationic stabilized polystyrene seed latex was prepared. Next, a portion of the seed latex was used in a continuous addition process to prepare a second latex containing a sulfonic acid functional monomer and a primary amine functional monomer.
The cationic seed latex was prepared in the following manner: to a 1-liter, 3-necked glass reaction flask equipped with a nitrogen inlet, a reflux condenser with a nitrogen outlet, and a mechanical stirrer, was added 20.0 g of styrene monomer, 40.0 g ARQUAD® 18-50 octadecyltrimethylammonium chloride surfactant (20.0 g active), 400 g deionized water, and 0.25 g of an aqueous ferric sulfate solution (0.25 g ferric sulfate in 100 g water). The flask was heated to 70° C. while the contents were stirred. To this heated, stirred flask was added 3.3 g of 30 weight percent hydrogen peroxide (1 g active) in a continuous addition stream over a period of 3 hours. After 0.5 hours of addition of the hydrogen peroxide, the addition of a stream of styrene was begun and 80 g of styrene was added over the next 2.5 hours. Syringe pumps were used as the continuous addition control means. Three hours after the beginning of the addition of the hydrogen peroxide, the stirring was stopped and the seed was removed from the heat to cool at room temperature. The result of this polymerization was a translucent, low viscosity dispersion with a solids content of 21.6 weight percent. The particle size is 398 Å (mean value) and 378 Å (median value).
The foam-forming latex was prepared from the above cationic seed latex by a continuous addition polymerization method using syringe pumps as the continuous addition control means. To a 1-liter, 3-necked, glass reaction flask equipped with a nitrogen inlet, a reflux condenser with a nitrogen outlet, and a mechanical stirrer was added water (206 g), and the cationic seed latex (7.00 g, 1.50 g active). The flask was heated to 90° C. while the contents were stirred. To this heated, stirred flask were added 5 streams continuously over a time of 4 hours while the temperature of the reaction flask was maintained at 90° C. Table 4 shows the addition streams. Table 5 shows the composition of the latex prepared with these addition streams. In these tables, AMPS stands for 2-acrylamido-2-methylpropane sulfonic acid (Chem. Abstracts No. 15214-89-8) and AEM.HCl stands for the 2-aminoethyl methacrylate hydrochloride (Chem. Abstracts No. 2420-94-2). After completion of the addition, polymerization was continued at 90° C. for 1 hour. The resulting latex was filtered and found to have a solids content of 37.7 weight percent. The particle size is 1439 Å (volume median diameter) and 1807 Å (volume mean diameter).
TABLE 4______________________________________Reagents Used to Prepare the LatexStream Component Amount (g)______________________________________1 Butyl Acrylate 87.5 Methyl Methacrylate 65.02 AEM•HCl in Water 17.3 (5.2 active)3 AMPS 0.75 Water 20.04 t-Butylhydroperoxide 0.90 Water 8.05 SFS 0.48 Water 8.0______________________________________
TABLE 5______________________________________Composition of the Foam-Forming Latex Molecular Weight Weight MoleMonomer (g/mol) Percent Percent______________________________________Butyl Acrylate 128.1 44.3 49.9Methyl Methacrylate 100.1 54.0 47.5AEM•HCl 166,6 1,57 2.3AMPS 207.1 0.137 0.25______________________________________
To 2.03 g of the latex was added 0.43 g of a 0.20 N NaOH solution. Upon agitating the bottle, the latex completely coacervated within 10 seconds. To 2.04 g of the latex was added 0.05 g of ARQUAD® 18-50 octadecyltrimethylammonium chloride surfactant (0.025 g active). The bottle was agitated and the latex formed a froth. Three incremental additions of 0.20 N NaOH solution were made in the following weights: 0.54 g, 0.44 g, and 0.59 g. The first two additions had no affect; however, the third was sufficient to initiate coacervation.
To a plastic bottle was added 13.15 g of the latex plus 0.06 g of ARQUAD® 18-50 octadecyltrimethylammonium chloride surfactant (0.03 g active). A Caframo stirrer Model BDC 3030 (Wiarton, Ontario) equipped with a Cowles-type blade was used to shear the mixture to froth it. The dispersion was stirred at 600 rpm for 30 seconds. The mixer speed was then increased to 1000 rpm for 2 minutes, followed by 1 minute at 1500 rpm and then another minute at 1000 rpm. At this point, a viscous froth was formed. To this frothed dispersion was added 1.5 g of Mg(OH) 2 while mixing was continued. Within 5 seconds some coacervation was observed. Mixing was continued for another 5 seconds, then the sample was removed. The froth appeared to have completely set into a solid shape. | Rapid set cellular articles can be prepared from a latex by the steps of: a) frothing a latex that contains a dispersed polymer having pendant cationic groups or adsorbing cationic molecules or both, and pendant acid groups; and b) rendering the frothed latex sufficiently basic to make the cellular article. The cellular articles of the present invention are advantageously prepared at ambient temperatures and pressures, and in the absence of organic solvents or CFCs. | 2 |
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BACKGROUND OF INVENTION
The use of ceiling panels, particularly but not exclusively for decoration, is well known. Ceiling panels are typically composed of sheet metal with an embossed decorative pattern or of non-metallic material, such as asbestos or cellulose-like materials. The non-metallic ceiling panels have many deficiencies. Consequently metal ceiling panels, particularly those fabricated of tin, are preferred. However, the installation of metal ceiling panels presents challenges.
Most non-suspended ceilings are constructed of sheetrock. Traditionally metal ceiling panels have been installed, that is, affixed to the ceiling, by using nails at the corners or at the perimeter of each individual ceiling panel. However, due to the nature of the composition of sheetrock, nails cannot adequately affix metal ceiling panels to sheetrock due to the inability of nails to adequately grip and hold firmly to the sheetrock and the resultant tendency of the nails to slip-out of overhead sheetrock over a period of time, thereby releasing the panels from the ceiling, which of course is most undesirable.
Consequently, the traditional approach to installing metal ceiling panels to sheetrock ceilings is to first install a plywood surface over the entire sheetrock ceiling, and to then subsequently nail each of the metal ceiling panels into the thusly installed plywood. This is a labor intensive, time consuming and costly installation procedure.
An alternative but equally undesirable approach is to install wooden strips on the sheetrock ceiling, and to then nail each of the metal ceiling panels into the wood strips. With this approach, it is essential for the wood strips to be aligned very carefully to assure that the strips do in fact align with the edges of the panels as they are installed. Although easier than covering an entire sheetrock ceiling with plywood prior to installation of metal ceiling panels, this wooden strip approach is also still a very a labor intensive, time consuming and costly installation procedure.
In addition, metal ceiling panels traditionally have been installed by being placed side-by-side with each other, without any interlocking mechanism to attach adjoining ceiling panels to each other during the installation process, or indeed otherwise. Such interlocking of contiguous ceiling panels would both facilitate the installation process and would also enhance the structural integrity of the installed metal ceiling panel matrix grid.
The manual dexterity necessary to install ceiling panels overhead is tremendous; not only does the installer need to assure proper alignment of each panel, but that installer must simultaneously also hold and support the panel in an overhead position while handling nails and a hammer.
An objective of the present invention is to solve the aforesaid problems.
BRIEF SUMMARY OF THE INVENTION
A preferred embodiment of the invention is the interlocking capability and characteristics of two or more ceiling panels to be installed contiguously with each other, particularly when installed onto a sheetrock ceiling surface as depicted in FIGS. 1 through 6 hereof.
This invention addresses and solves the traditional challenges and problems encountered prior to this invention with the installation of metal ceiling panels by avoiding the costly and time consuming installation of plywood or wooden strips between the sheetrock ceiling and the metal ceiling panels to be attached to that sheetrock ceiling.
This invention further addresses and solves the traditional challenges and problems encountered prior to this invention by the installer having had to simultaneously hold the ceiling panel in place overhead during the installation process, also assuring proper positioning and alignment of each panel, while also handling the affixing nails and operating the hammer by which the nails were driven through the ceiling panel and into the underlying plywood or wood strips.
The present invention solves the foregoing problems. The resultant ability for a ceiling panel to be held in position during installation other than by being continually held in place by the hands of the installer while the installer is simultaneously juggling nails and hammer, coupled with the ability to install metal ceiling panels directly to a sheetrock ceiling without the otherwise need for plywood or wood strips, results in the installation of metal ceiling panels being appreciably less labor intensive, less time consuming and consequently less expensive than otherwise.
BRIEF DESCRIPTION OF THE DRAWINGS
The illustration of a preferred embodiment of the invention is shown on the accompanying drawings in which:
FIG. 1 is a view of the finished, embossed front face of a representation of a typical ceiling panel.
FIG. 2 is an isometric view of a ceiling panel, looking upward toward a ceiling on which the said ceiling panel is to be installed, simultaneously showing bottom and side perspectives.
FIG. 3 is a depiction of a matrix grid of multiple ceiling panels installed on a ceiling.
FIG. 4 is a cross-section of the male interlock component feature of the invention, not inserted into the female interlock component feature of the invention.
FIG. 5 is a cross-section of female interlock component feature of the invention, without the male interlock component feature of the invention inserted therein.
FIG. 6 is a cross-section of the male interlock component feature of the invention inserted into the female interlock component feature of the invention, showing a series of installed contiguous ceiling panels.
DETAILED DESCRIPTION OF THE INVENTION
One preferred embodiment of the invention is depicted as a metal ceiling panel in FIGS. 1 through 6 hereof, which provides the ability for the installation of a ceiling panel directly onto a sheetrock ceiling without the otherwise need for first installing a plywood surface or wood strips to the sheetrock ceiling.
This is accomplished through the combination of an interlocking mechanism within each ceiling panel by virtue of which immediately adjoining ceiling panels are reversibly and removably connected to each other prior to being affixed to the sheetrock ceiling in conjunction with other ceiling panels then being affixed to the sheetrock ceiling by screws inserted through holes in the flanges of the ceiling panels.
FIG. 1 is a view of the finished front face of a ceiling panel ( 101 ), in which there are four side edges shown as ( 103 ), ( 105 ), ( 107 ), and ( 109 ).
FIG. 2 is an isometric view of the ceiling panel depicted in FIG. 1 , but with the side edges which had been depicted in FIG. 1 as ( 103 ), ( 105 ), ( 107 ), and ( 109 ) now depicted for emphasis in a magnified, out-of-proportion depiction as ( 203 ), ( 205 ), ( 207 ), and ( 209 ).
FIG. 3 is a depiction of a matrix grid ( 310 ) comprised of twelve of the ceiling panels ( 101 ) depicted in FIG. 1 . The use of twelve ceiling panels in this matrix grid is only for purposes of illustration, with the matrix grid actually being any number of ceiling panels configured in an interconnected matrix grid of such ceiling panels.
FIG. 4 depicts a cross-section of the male interlock component feature of the invention ( 401 ), in which there are both convex protrusions ( 403 ) and ( 405 ), and also resultant concave indentations ( 407 ) and ( 409 ) from the plane of the male interlock component feature of the invention ( 401 ).
The use of two such protrusions and two such indentations is only for purposes of illustration, with the actual number of such protrusions and indentations being one or more, but certainly not limited to two.
The surfaces of protrusions ( 403 ) and ( 405 ) can be either smooth or alternatively can be coated, treated or otherwise conditioned or textured to thereby increase the coefficient of friction between said surfaces ( 403 ) and ( 405 ) with the surfaces of any materials with which they are placed in contact, including the surface of the interior wall ( 511 ) of the female interlock component feature of the invention.
Similarly, the surfaces of indentations ( 407 ) and ( 409 ) can be either smooth or alternatively can be coated, treated or otherwise conditioned or textured to thereby increase the coefficient of friction between said surfaces ( 407 ) and ( 409 ) with the surfaces of any materials with which they are placed in contact, including the surfaces of protrusions ( 507 ) and ( 509 ) on the surface of the interior walls ( 511 ) of the female interlock component feature of the invention.
FIG. 5 depicts a cross-section of the female interlock component feature of the invention ( 501 ), in which there are both convex protrusions ( 507 ) and ( 509 ), and also resultant concave indentations ( 503 ) and ( 505 ) from the plane of the female interlock component feature of the invention ( 501 ).
FIG. 5 also depicts a relatively flat surface ( 511 ) facing and directly opposite to surfaces of protrusions ( 507 ) and ( 509 ).
In addition, FIG. 5 depicts a hole ( 513 ) through which a screw or other affixing means may be inserted to affix the ceiling panel, of which the female interlock component feature of the invention ( 501 ) is a part, onto a sheetrock ceiling.
The use of two such protrusions and two such indentations is only for purposes of illustration, with the actual number of such protrusions and indentations being one or more, but certainly not limited to two.
The surfaces of protrusions ( 507 ) and ( 509 ) can be either smooth or alternatively can be coated, treated or otherwise conditioned or textured to thereby increase the coefficient of friction between said surfaces ( 507 ) and ( 509 ) with the surfaces of any materials with which they are placed in contact, including the surfaces of indentations ( 407 ) and ( 405 ).
FIG. 6 depicts a cross-section of portions of two ceiling panels ( 601 ) and ( 605 ), each of which is connected to an entire ceiling panel ( 603 ).
Each ceiling panel in that preferred embodiment depicted in the FIGS. 1 through 6 hereof has two male side edges ( 207 ) and ( 209 ) and two female side edges ( 203 ) and ( 205 ). One or more holes ( 211 ) exist in each flange portion of the said female side edges ( 203 ) and ( 205 ) to allow for the insertion of a screw or other affixing means by which the ceiling panel is affixed to a sheetrock ceiling.
In the installation process, the said male side edges ( 207 ) and ( 209 ) are inserted into the female side edges ( 203 ) and ( 205 ), respectively. The said ceiling panels, when thusly connected with each other, interlock in a “snap-lock” fashion, thereby self-aligning themselves with other ceiling panels previously installed in the matrix grid ( 301 ) and providing a means for the ceiling panels subsequently installed to be similarly self-aligned.
In addition, once so connected and interlocked the said ceiling panels are relatively self-supporting, and need no longer be held in the hands of the installer. Consequently, the installer then has both of his hands free to use for holding nails, screws, hammers, screw drivers or any other tools used to affix the ceiling panel matrix grid to the sheetrock ceiling.
As the male interlock component feature of the invention as depicted in FIG. 4 is inserted into the female interlock component of the invention as depicted in FIG. 5 , (as shown fully inserted in FIG. 6 ), surfaces ( 407 ) and ( 403 ) are initially placed in contact with surfaces ( 509 ) and ( 511 ), respectively, and as the insertion continues, those surfaces ( 407 ) and ( 403 ) are then and finally placed in contact with surfaces ( 507 ) and ( 511 ), respectively, while simultaneously surfaces ( 409 ) and ( 405 ) are then and finally placed in contact with surfaces ( 509 ) and ( 511 ), respectively.
During and in the course of the aforementioned insertion procedure, the said protrusions and indentations of the said male interlock component feature of the invention ( 401 ) and the said protrusions an indentations of the said female interlock component feature of the invention ( 501 ) are temporarily plastically flexibly displaced or deformed, or both, to thereby allow for the said insertion, after which insertion the said protrusions and indentations return to their original shapes and forms.
Upon completion of the said insertion procedure, there is a resulting secure interlock between the two adjacent ceiling panels thus connected. Notwithstanding the said interlock, the said connected ceiling panels are still forcibly separable by applying sufficient force to one ceiling panel in a direction which is opposite to that simultaneously applied to the other then connected second ceiling panel.
Each ceiling panel ( 101 ) in the matrix grid ( 301 ) is affixed to the ceiling by means of screws ( 607 ) inserted through screw holes ( 513 ).
It is contemplated that the inventive concepts herein described may be variously otherwise embodied and it is intended that the appended claims be construed to include alternative embodiments of the invention except only insofar as limited by prior art. | A panel, for installation on a ceiling as a component of a matrix grid of similar panels, with the ceiling panels capable of being installed directly on sheetrock ceilings without the otherwise need for affixing a wooden structure to the sheetrock ceiling before affixing the ceiling panels. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a switch, and more particular, to a thin-type switch mountable on a printed board.
2. Background Art
Conventionally, a thin-type switch mountable on a printed board comprises, for example, a housing having a space therein, a first stationary terminal having an end provided outside the housing and the other end provided inside the housing and provided with a contact portion having a contact groove, a second stationary terminal having an end provided outside the housing and the other end provided inside the housing and provided with a contact portion, a contact piece provided in the housing, provided at an end thereof with a stationary portion, which is latched in the contact groove of the first stationary terminal to contact with the contact portion of the first stationary terminal, and at the other end thereof with a moving portion capable of contacting with the contact portion of the second stationary terminal, the contact piece being biased by a coil spring formed at an intermediate portion thereof in a direction of twist and in a direction of compression, and an operating body provided at a base end thereof with a support portion, which is provided in the housing and defines a center of swinging, the remaining portion thereof being capable of swinging about the support portion as the center of swinging, and formed with a push surface, which abuts against the contact piece, the operating body swinging to enable pushing the contact piece in the direction of twist (see JP-A-2004-327115).
With the switch described above, however, the operating body 60 directly pushes the moving portion 50 e being one end of the contact piece 50 made of a coil spring, and the contact portion 50 g of the operating body slides on the contact portion 40 c of the second stationary terminal while twisting the contact piece 50 . Therefore, when the operating body 60 , the contact piece 50 , etc. involve dispersion in outside dimension and assembly accuracy, unexpected elastic deformation such as warping of the moving portion 50 e , or the like is liable to occur. Consequently, dispersion is liable to generate in contact pressure, at which the contact portion 50 g of the operating body contacts with the contact portion 40 c , and so the operating characteristics are liable to become unstable. Accordingly, when it is tried to ensure a desired operating characteristics, the switch described above needs high part accuracy and assembly accuracy, so that manufacture is not easy.
Also, in order to perform contact switchover in the switch described above, it is necessary to increase a twist angle of the moving portion 50 e . Therefore, there is caused a problem that a large operating force is necessary and a torsional moment acting on the contact piece 50 becomes large to make the switch susceptible to fatigue and short in life.
SUMMARY OF THE INVENTION
In view of the problem described above, the invention has its object to provide a switch, which can be operated with a small operating force and is long in life and easy in manufacture.
In order to solve the problem, a switch according to the invention has a construction comprising a base, a moving contact piece made of a coil spring and having one end thereof, which is supported pivotally on the base, coming into pressure contact with a common stationary contact, an operating lever having one end thereof supported pivotally on the base and having a drive part, which extends from the one end, pushing a coil portion of the moving contact piece, and a cover having a planar shape capable of covering the base and fixed to the base to compress the coil portion, and in which the operating lever pushes the coil portion of the moving contact piece to give thereto a torsional moment whereby the moving contact piece turns about an end thereof, the coil portion of the moving contact piece slides on a bottom surface of the base, and the other end of the moving contact piece slides on at least one stationary contact exposed from an inner surface of the base.
According to the invention, the operating lever pushes the coil portion of the moving contact piece, which is made of a coil spring, so that the other end of the moving contact piece is not subjected to unexpected elastic deformation and a switch is obtained, which can ensure a predetermined contact pressure and is stable in operating characteristics.
Also, even when the base, the operating lever, etc. involve dispersion in dimensional accuracy and assembly accuracy, the moving contact piece is elastically deformed to absorb an error, so that high part accuracy and assembly accuracy are not needed and manufacture is easy.
Further, since the moving contact piece turns about an end thereof and the other end thereof slides on the inner surface of the base, a twist angle of the whole moving contact piece is smaller than that in the related art. Therefore, since a torsional moment acting on the moving contact piece is small, there is produced an effect that a large operating force is not necessary and a switch is obtained, which is hardly susceptible to fatigue and long in life.
According to the embodiment of the invention, the stationary contact exposed from the inner surface of the base may comprise a normally opened stationary contact, or a normally closed stationary contact, or a normally opened stationary contact and a normally closed stationary contact.
According to the embodiment, there is obtained a switch, for which freedom in selecting a product is increased and which is wide in usage.
A switch according to another invention has a construction comprising a base, a moving contact piece made of a coil spring and having one end thereof, which is supported pivotally on the base, coming into pressure contact with a common stationary contact, an operating lever having one end thereof supported pivotally on the base and having a drive part, which extends from the one end, pushing a coil portion of the moving contact piece, and a cover having a planar shape capable of covering the base and fixed to the base to compress the coil portion, and in which the operating lever pushes the coil portion of the moving contact piece to give thereto a torsional moment whereby the moving contact piece turns about an end thereof, the coil portion of the moving contact piece slides on at least one stationary contact exposed from a bottom surface of the base, and the other end of the moving contact piece slides on an inner surface of the base.
According to the invention, the operating lever pushes the coil portion of the moving contact piece, which is made of a coil spring, whereby the coil portion compressed by the cover comes into pressure contact with the stationary contact to enable ensuring a predetermined contact pressure, so that a switch is obtained, which is stable in operating characteristics.
Also, even when the base, the operating lever, etc. involve dispersion in dimensional accuracy and assembly accuracy, the moving contact piece is elastically deformed to absorb an error, so that high part accuracy and assembly accuracy are not needed and manufacture is easy.
Further, since the moving contact piece turns about an end thereof and the other end thereof slides, a twist angle of the whole moving contact piece is smaller than that in the related art. Therefore, since a torsional moment acting on the moving contact piece is small, a large operating force is not necessary and a switch is obtained, which is hardly susceptible to fatigue and long in life.
According to the embodiment of the invention, the stationary contact exposed from the bottom surface of the base may comprise a normally opened stationary contact and a normally closed stationary contact.
The embodiment produces an effect that there is obtained a switch, for which freedom in selecting a product is increased and which is wide in usage.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view showing the whole of a first embodiment of a switch according to the invention;
FIG. 2 is an exploded, perspective view showing the switch shown in FIG. 1 ;
FIG. 3A is a perspective view showing a base of the switch shown in FIG. 2 , and FIG. 3B is a perspective view showing contact terminals shown in FIG. 2 ;
FIGS. 4A and 4B are perspective views showing the switch shown in FIG. 1 before and after operation;
FIGS. 5A , 5 B, and 5 C are horizontal, cross sectional views showing the switch shown in FIG. 1 before, during, and after operation;
FIGS. 6A and 6B are perspective views showing a base and contact terminals according to a second embodiment of the invention;
FIGS. 7A and 7B are perspective views showing a switch according to the second embodiment shown in FIG. 6 before and after operation;
FIGS. 8A , 8 B, and 8 C are plan views showing the switch shown in FIG. 6 before, during, and after operation;
FIGS. 9A , 9 B, and 9 C are horizontal, cross sectional views illustrating different methods of using the first, second, and third embodiments according to the invention;
FIGS. 10A , 10 B, and 10 C are horizontal, cross sectional views showing fourth, fifth, and sixth embodiments according to the invention; and
FIGS. 11A and 11B are a plan view and a cross sectional view illustrating different methods of using the fourth embodiment.
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the invention will be described below with reference to the accompanying drawings of FIGS. 1 to 11 .
A first embodiment comprises, as shown in FIGS. 1 to 5 , a base 10 , into which stationary contact terminals 20 , 21 are insert-molded, and which is square in plan, a moving contact piece 30 made of a coil spring, an operating lever 40 supported pivotally on the base 10 , and a cover 50 that covers the base 10 . In addition, an exemplary product as actually assembled has an outside dimension of a total height 0.9 mm, a base width of 3.0 mm, and a length of 3.5 mm.
The base 10 comprises substantially U-shaped side walls 11 , 12 , 13 provided continuously and protrusively along a peripheral edge of an upper surface thereof, and the stationary contact terminals 20 , 21 , respectively, are insert-molded on the opposite side walls 11 , 13 . Positioning steps 11 a , 13 a , respectively, are provided on outer side surfaces of the side walls 11 , 13 , on which the stationary contact terminals 20 , 21 are insert-molded, while a positioning recess 12 a is formed on an outer side surface of the side wall 12 positioned between the side walls 11 , 13 . Further, a low step 13 b is formed on an inside edge of the upper surface of the side wall 13 , on which the stationary contact terminal 21 is insert-molded, and a latch hole 14 is provided on the step 13 b to have an end 32 of the moving contact piece 30 latched thereon. A common stationary contact 21 a is exposed from an inner peripheral surface of the latch hole 14 . Also, a normally opened stationary contact 20 a of the stationary contact terminal 20 is exposed from an inner surface of the side wall 11 , on which the stationary contact terminal 20 is insert-molded. Further, the base 10 comprises spindles 16 , 17 protrusively provided at adjacent corners on that outer peripheral edge of the upper surface, which is not provided with any side wall, to support an operating lever 40 described later, and a coming-off preventive projection 18 protrusively provided between the spindles 16 , 17 to prevent coming-off of the operating lever 40 .
An end 32 of the moving contact piece 30 made of a coil spring, which extends from an upper end of a coil portion 31 to be bent, is inserted into the latch hole 14 of the base 10 and pivotally supported and is press-contact with the common stationary contact 21 a . On the other hand, the other bent end 33 functioning as a moving contact can slide on the inner surface of the side wall 11 of the base 10 and contact with the normally opened stationary contact 20 a . The moving contact piece 30 is arranged so that the coil portion 31 slides on a bottom surface of the base 10 .
The operating lever 40 comprises an axial hole 41 positioned in a central position of a substantially sector shape in plan view and fitted rotatably onto the spindles 16 , 17 of the base 10 . An operating part 42 and a drive part 43 extend at a predetermined angle about the axial hole 41 , and an arcuate groove 45 about the axial hole 41 is formed by connecting the operating part 42 and the drive part 43 to each other by means of a reinforcement rib 44 . In addition, the axial hole 41 of the operating lever 40 can be fitted on either of the spindles 16 , 17 of the base 10 , and the drive part 43 is shaped to be able to appropriately drive the moving contact piece 30 even in the case where the operating lever 40 is supported by either of the spindles 16 , 17 .
The cover 50 has a planar shape to enable covering the base 10 . However, an insulating sheet (not shown) may be stuck integrally to a roof surface of the cover at need. The cover 50 is bent vertically from three adjacent outer peripheral edges to form engagement tongue pieces 51 (not shown), 52 , 53 , and bendable pawls 51 a (not shown), 52 a , 53 a , respectively, are extended from lower end edges of the tongue pieces 51 , 52 , 53 .
Subsequently, an explanation will be given to a method of assembling the switch according to the embodiment.
First, the end 32 of the moving contact piece 30 is latched and supported pivotally on the latch hole 14 of the base 10 , into which stationary contact terminals 20 , 21 are insert-molded, to be accommodated on the upper surface of the base 10 . Thereby, the end 32 of the moving contact piece 30 is brought into contact with the common stationary contact 21 a and the other end 33 can contact with the normally opened stationary contact 20 a , while the coil portion 31 is placed slidably on the upper surface of the ridge 15 . The axial hole 41 of the operating lever 40 is fitted on, for example, the spindle 17 of the base 10 to be supported pivotally thereon Then, the cover 50 is put on the base 10 to be pushed thereagainst whereby the tongue pieces 51 , 53 and the tongue piece 52 , respectively, are engaged by the positioning steps 11 a , 13 a and the recess 12 a to be positioned. Thereby, the coil portion 31 is compressed, so that a lowermost end surface of the coil portion 31 can contact with the bottom surface of the base 10 at a predetermined contact pressure. When the operating lever 40 is pushed inward against the spring force of the moving contact piece 30 in this state, the drive part 43 gets over the coming-off preventive projection 18 and the projection 18 is latched in the arcuate groove 45 . Therefore, even when the operating lever 40 is biased outward by the moving contact piece 30 , it is prevented from coming off and the end 32 of the moving contact piece 30 is brought into pressure contact with the common stationary contact 21 a at a predetermined contact pressure. Thereafter, the assembling work is completed by inward by bending the engagement pawls 51 a , 52 a , 53 a of the tongue pieces 51 , 52 , 53 and fixing the cover 50 to the base 10 .
Subsequently, an explanation will be given to a method of operating the switch.
In the case where any operating force is not exerted on the operating lever 40 , a spring force generated on the moving contact piece 30 by an action of beforehand loaded torsion causes the end 32 to be brought into pressure contact with the common stationary contact 21 a and the other end 33 to be brought into pressure contact with the inner surface of the side wall 11 at a predetermined contact pressure.
When the operating part 42 of the operating lever 40 is pushed in, the drive part 43 pushes the coil portion 31 as shown in FIGS. 4 and 5 . Therefore, a torsional moment acting on the coil portion 31 increases, so that the operating lever 40 turns about the spindle 17 against the spring force of the moving contact piece 30 and the other end 33 slides on the inner surface of the side wall 11 to contact with the normally opened stationary contact 20 a.
When a load on the operating lever 40 is released, the operating lever 40 is pushed back outward by the spring force of the moving contact piece 30 . Therefore, the moving contact piece 30 turns about the end 32 of the moving contact piece 30 in a reverse direction to the direction described above, and the other end 33 thereof slides on the stationary contact 20 a to effect opening.
According to the embodiment, the moving contact piece 30 turns deforming elastically to open and close the contact whereby a switch is obtained, which does not need as high part accuracy and assembly accuracy as those in the related art, and which is high in productivity and stable in operating characteristics.
In particular, since the other end 33 of the moving contact piece 30 moves sliding on the stationary contact 20 a , an angle of torsion generated on the moving contact piece 30 is small as compared with the case where the other end does not move. Therefore, an internal stress generated on the moving contact piece 30 is small and fatigue failure is hard to occur.
Further, according to the embodiment, not only an operation in a counterclockwise direction but also an operation in a clockwise direction can be accommodated by fitting the operating lever 40 onto the spindle 16 . Therefore, since parts can be used in common, a single metallic mold can serve, thus enabling reduction in production cost. Consequently, according to the embodiment, there is an advantage that a switch capable of accommodating operation in three directions can be manufactured by a single kind of metallic mold.
A second embodiment provides a normally closed contact type, in which a normally closed stationary contact 20 b is arranged on an inner surface 11 of a base 10 as shown in FIGS. 6 and 8 .
That is, as shown in FIG. 6 , a normally closed stationary contact 20 b is exposed to the inner surface 11 of the base 10 . As shown in FIGS. 7 and 8 , when an operating lever 40 is pushed in, a torsional moment acting on a coil portion 31 increases, so that the other end 33 slides on the normally closed stationary contact 20 b . When a load on the operating lever 40 is released, the operating lever 40 is pushed back outward by the spring force of the moving contact piece 30 to return to an original position. Since the rest is the same as that in the embodiment described above, the same parts as those in the latter are denoted by the same reference numerals as those in the latter, and an explanation therefor is omitted.
In addition, as shown in FIGS. 9A and 9B the first embodiment and the second embodiment may be made clockwise by mounting the operating lever 40 on the spindle 16 .
According to a third embodiment, a normally closed stationary contact 20 a and a normally opened stationary contact 22 a are exposed to an inner surface of a side wall 11 .
Accordingly, when an operating lever 40 is pushed in, a torsional moment acting on a coil portion 31 of a moving contact piece 30 increases, so that the moving contact piece 30 turns about an end 32 . Therefore, after the other end 33 slides on the normally closed stationary contact 20 a , it contacts with the normally opened stationary contact 21 b to switch over the contact. Since the rest is the same as that in the embodiment described above, the same parts as those in the latter are denoted by the same reference numerals as those in the latter, and an explanation therefor is omitted.
According to a fourth embodiment, a normally opened stationary contact 21 b is arranged on a bottom surface of a base 10 as shown in FIG. 10A .
According to the embodiment, since the normally opened stationary contact 21 b is arranged on the bottom surface of the base 10 , a coil portion 31 of a moving contact piece 30 contacts with the stationary contact 21 b at a constant contact pressure, so that there is an advantage that dispersion is hard to generate in operating characteristics.
The embodiment may be of course made counterclockwise by mounting the operating lever 40 on the spindle 17 as shown in FIG. 11 .
Also, a normally closed stationary contact 21 c may be arranged on a bottom surface of the base 10 as shown in FIG. 10B (a fifth embodiment). Also, as shown in FIG. 10C , a normally closed stationary contact 20 d and a normally opened stationary contact 21 b may be arranged on a bottom surface of the base 10 (a sixth embodiment).
Like the fourth embodiment described above, the fifth and sixth embodiments have an advantage that a switch can be obtained, in which dispersion in contact pressure is hard to generate and which has a stable operating characteristics.
In addition, according to the embodiments, both an operation in a clockwise direction and an operation in a counterclockwise direction can be accommodated by changing a position, in which the operating lever 40 is mounted to the base 10 .
Also, while according to the embodiments, an end of the moving contact piece extending from above is supported pivotally on the base, the other end thereof extending from under may be supported pivotally on the base.
The switch according to the invention is of course applicable to a switch other than ones according to the embodiments. | A switch is provided, which is stable in operating characteristics and can be operated with a small operating force, and which is long in life and easy to manufacture. The switch comprises a base, a moving contact piece having one end thereof, which is supported pivotally on the base, coming into pressure contact with a common stationary contact, an operating lever having one end thereof supported pivotally on the base and having a drive part, which extends from the one end, pushing a coil portion of the moving contact piece, and a cover fixed to the base to compress the coil portion. The operating lever pushes the coil portion of the moving contact piece whereby the moving contact piece turns about an end thereof, the coil portion slides on a bottom surface of the base, and the other end of the moving contact piece slides on a stationary contact exposed from an inner surface of the base. | 7 |
BACKGROUND AND FIELD OF THE INVENTION
The present invention relates to novel organosiloxane compositions comprising a platinum group metal hardening catalyst and a ketone compound transitory inhibitor therefor. More especially, this invention relates to organopolysiloxane compositions which are stable for appreciable periods of time at ambient temperature, which period of stability is varied depending upon the field of use to which a given composition is to be put, which compositions harden under appropriate curing conditions (heat treatment, treatment with U.V. or infra-red rays, treatment with ionizing radiation, and the like). This hardening or curing is carried out via the well-known reactions of .tbd.SiH groups with unsaturated olefin radicals bonded to silicon atoms, such reactions being catalyzed by a platinum group metal.
The subject compositions are generally stored before use in the form of two-component or two-pack compositions, the two components being intimately mixed immediately before use to form a single composition, and the principal problem is to avoid premature gelation of such compositions. It is hence necessary that these compositions incorporate a transitory inhibitor for the catalyst, which inhibitor inhibits or retards the catalytic activity at ambient temperature, but whose inhibitory activity disappears at elevated temperatures during the treatment for cross-linking of the compositions.
SUMMARY OF THE INVENTION
Accordingly, a major object of the present invention is the provision of improved organopolysiloxane compositions which can be stored in two-component form and which comprise Si-vinyl .tbd.SiH radicals and a platinum group metal curing catalyst, which compositions, at point in time of their use after intimate admixture of said two components, do not exhibit inopportune or premature gelation for appropriate periods of time and thus have useful pot or bath lives, said premature gelation being avoided by the presence therein of a ketone compound which inhibits the activity of the platinum group metal catalyst at non-curing temperatures.
Another object of the present invention is the provision of organopolysiloxane compositions of the above type in which the inhibitor, in the intended applications thereof, efficiently retards the catalytic cross-linking activity of the catalytic platinum complex at temperatures lower than the cross-linking temperatures of such compositions, but whose inhibitory influence is insufficient to prevent effective cross-linking at elevated temperatures.
Another object of this invention is the provision of compositions of the above type which may be used to form cross-linked compositions in the form of resins, elastomers, gels or foams, and which are stored before use, preferably under protection from air, as 2 components, one of the 2 components incorporating the catalyst, but which organopolysiloxanes are facilely cross-linked into elastomers after the 2 components have been mixed and heated to a temperature above 80° C., the mixture of the 2 components having, prior to being heated, a pot life of more than several hours and not unusually up to several days, and even several weeks. Such compositions are especially useful for coating metal articles or for insulation of electrical equipment with or without fillers and which cross-link into elastomers having admirable mechanical strengths and flexibility.
Yet another object of the present invention is the provision of a novel catalyst inhibitor of the above type which is non-toxic and non-lachrymatory.
Still another object of the present invention is the provision of coating compositions of the above type which are devoid of fillers, which contain or do not contain any solvent material, and which are capable of rendering a substrate such as metal foils, glass, plastic or paper, non-adherent to other materials to which they would normally adhere. The subject compositions also impart excellent anti-stick properties, after the cross-linking thereof, to supports or substrates coated, therewith, which properties are preserved with the passage of time, the hardened or cross-linked layers having a good resistance to friction and, in particular, are not removed by abrasion upon conveying the coated supports over the guide rollers of coating or adhesive-applying machines.
In the description which follows, the percentages and parts are all expressed by weight, except where otherwise indicated.
It is recognized that a number of inhibitors for the platinum group metal catalysts are already known to this art, such inhibitors being used either alone or in combination and which in part relate to the satisfaction of certain of the objectives envisaged by the present invention.
Thus, the prior art has proposed for such purposes, for example, alkylthioureas (U.S. Pat. No. 3,188,299), triallylisocyanurates (U.S. Pat. No. 3,882,083), dialkylacetylenedicarboxylates (U.S. Pat. No. 4,347,346), diallylmaleates (U.S. Pat. No. 4,256,870), and a linear or cyclic alkylvinylsiloxane as described in U.S. Pat. Nos. 3,516,946 and 3,775,452 and in French Pat. No. 1,548,775.
In U.S. Pat. No. 3,445,420, there is described an acetylenic organic inhibitor having a boiling point of at least 25° C. and having at least one --C.tbd.C-- group, such acetylenic compound being devoid of nitrogen, carboxyl groups, phosphorus, mercapto groups and carbonyl groups in the α-position relative to the carbon atoms constituting the site of acetylenic unsaturation.
It has now unexpectedly been discovered, however, that organic acetylenic compounds which necessarily have a carbonyl group in the α-position relative to the carbon atoms comprising the site of acetylenic unsaturation, and which are also devoid of nitrogen and phosphorus atoms and carboxyl and mercapto groups in the α-position relative to the carbon atoms constituting the site of acetylenic unsaturation, have a platinum inhibitory effect in Si-vinyl.tbd.SiH organopolysiloxane compositions, which effect is quite notable and satisfies all of the objectives of the present invention.
Briefly, the present invention features organopolysiloxane compositions comprising:
(1) at least one organopolysiloxane having at least one vinyl radical per molecule, the remaining radicals either being mono- or divalent organic radicals which do not adversely affect the platinum catalysis;
(2) at least one organohydropolysiloxane containing at least 3 hydrogen atoms bonded to a silicon atom per molecule, the remaining radicals either being mono- or divalent organic radicals, preferably devoid of aliphatic unsaturation, and also not adversely affecting the platinum catalysis;
(3) a catalyst which is a platinum group metal complex, in catalytically effective amounts which catalyze the reaction of the organopolysiloxane (1) with the organohydropolysiloxane (2); and
(4) at least one platinum catalysis inhibitor comprising an organic compound having a boiling point of at least 25° C. and at least one site of acetylenic unsaturation, and also having a carbonyl group in the α-position relative to the carbon atoms constituting the site of acetylenic unsaturation, the said inhibitor (4) being present in sufficient amounts to inhibit premature gelation of the compositions at ambient temperature, but in amounts insufficient to prevent the cross-linking thereof at higher temperatures.
DETAILED DESCRIPTION OF THE INVENTION
More particularly according to the present invention, the organopolysiloxanes (1) advantageously comprise recurring structural units having the average general formula: ##STR1## in which each R denotes a radical selected from among a monovalent hydrocarbon radical having from 1 to 12 carbon atoms, a monovalent halogenated hydrocarbon radical having from 1 to 12 carbon atoms, a cyanoalkyl radical having from 3 to 4 carbon atoms, a cycloalkyl or halogenocycloalkyl radical having from 3 to 8 carbon atoms and containing from 1 to 4 chlorine and/or fluorine atoms, and an aryl, alkylaryl or halogenoaryl radical having from 6 to 8 carbon atoms and containing from 1 to 4 chlorine and/or fluorine atoms, with R preferably being a methyl radical, and R' denotes an alkenyl radical selected from among vinyl, allyl, methallyl, butenyl or pentenyl radicals, or an alkynyl radical selected from among an ethynyl, propynyl or butynyl radical. R' preferably is the vinyl or allyl radical, and still more preferably is the vinyl radical; e and f have the same definitions as for the below compound (II).
The organohydropolysiloxanes (2) advantageously comprise recurring structural units having the average general formula: ##STR2## in which R has the same definition as above, e is a number ranging from 0.5 to 2.49, f is a number ranging from 0.001 to 1, and the sum of e plus f ranges from 1 to 2.5.
The polymers of the formula (I) are well known to this art and are described, in particular, in U.S. Pat. Nos. 3,220,972, 3,344,111 and 3,434,366.
A representative copolymer has the following general formula (III): ##STR3## in which R is preferably a methyl group and R' a vinyl group, the viscosity of the polymer ranges from 40 to 100,000 mPa.s at 25° C., and n and m are integers selected such that the content of vinyl groups does not exceed 10% by weight, and preferably 3%, with m optionally being equal to 0.
The organohydropolysiloxanes (2) include fluid materials which preferably do not comprise an olefinic double bond, but which indeed comprise at least 3 hydrogen atoms per molecule in the form of the .tbd.Si--H group. Such polymers (2) are, for example, described in U.S. Pat. Nos. 3,220,972, 3,341,111 and 3,436,366.
The organohydropolysiloxanes (2), moreover, can either be linear or cyclic in nature.
A representative linear copolymer has the following general formula (IV): ##STR4## wherein the viscosity of the polymer ranges from 40 to 100,000 mPa.s and n and m are integers such that the content of hydrogen atoms bonded to silicon does not exceed 1.67% by weight and preferably ranges from 0.1 to 1.6% by weight, with n optionally being equal to 0.
The ratio between the hydrogen atoms bonded to silicon in the organohydropolysiloxanes (2) and the sum of the vinyl, alkenyl and alkynyl radicals bonded to silicon in the organopolysiloxanes (1) is advantageously at least 0.5 : 1.
The present invention features compositions of the above type, the intimate admixture of the four (4) components of which produce, after heating to a temperature above 80° C., preferably above 100° C., cross-linked compositions in the form of resins, elastomers, gels or foams, said admixture exhibiting no untimely or premature cross-linking for several hours, generally several days and sometimes several weeks. The inhibitors and the catalysts which may be employed are the same as those described below with respect to the coating compositions. When the ratio of the hydrogen atoms which are bonded to silicon in the organohydropolysiloxanes (2) to the sum of the vinyl, alkenyl and alkynyl radicals which are bonded to silicon in organopolysiloxanes (1) is less than 0.5, the cross-linking is characteristically insufficient. This ratio may be greater than 2 when it is desired to produce elastomer foams.
The usual fillers and additives may be added to reduce shrinkage during cross-linking and to improve mechanical properties, weather resistance, fire resistance, and the like. It is thus possible, for example, to add fumed silica, precipitated silica, ballotini, alumina, iron oxide, carbon black, calcium carbonate, magnesium carbonate, pigments, antioxidants, and the like. When the composition contains fillers, particularly silica, it is advantageous that they be treated with a silazane, for example, hexamethyldisilazane. The quantity of inhibitor may advantageously range from 0.01 to 3%, preferably from 0.05 to 0.5% relative to the total weight of the composition.
The compositions of the invention typically exhibit a strong inhibition to hardening, whether they be used as such or diluted in a solvent. When they are dispersed or diluted in a solvent, a volatile organic solvent is used which is compatible with the composition, selected, for example, from among the alkanes, petroleum cuts which contain paraffinic compounds, toluene, heptane, xylene, isopropanol, methyl isobutyl ketone, tetrahydrofuran, chlorobenzene, chloroform, 1,1,1-trichloroethane, and derivatives of monoethylene glycol and of methylene glycol.
The solvent preferably comprises from 50 to 99% by weight of the dispersion.
By evaporating the solvent from the dispersion, the composition hardens and such dispersions are therefore useful as coating compositions for metal, wood and glass articles and for flexible paper sheets, plastic, and the like.
The compositions of the invention can also be employed as solvent-free compositions which can be used to render materials such as metal foils, glass, plastics or paper, non-adherent to other materials to which it would normally adhere, and, in the case of a solvent-free composition, same advantageously has a viscosity not exceeding 5,000 mPa.s, and which preferably ranges from 10 to 4,000 mPa.s at 25° C., and the ratio between the hydrogen atoms bonded to silicon in the organohydropolysiloxanes (2) and the sum of the vinyl, alkenyl and alkynyl radicals bonded to silicon in the organopolysiloxanes (1) is at least 0.5:1 and typically is less than 2:1, such ratio also being applicable to the resins with solvent.
The invention therefore also features a process which enables sheets of flexible material to be made non-adherent to surfaces to which they normally adhere, which process is characterized in that it comprises applying a quantity of composition according to the invention, generally from 0.1 to 5 g per m 2 of surface to be coated, and then cross-linking the composition by any suitable means.
The gelation times of these compositions, whether diluted or not, can be greater than 20 hours at ambient temperature, and the catalyst is reactivated at a higher temperature, typically exceeding 80° C.
The solvent-free, namely, the undiluted compositions are applied by means of devices which are suitable for depositing small amounts of liquids in a uniform manner. For this purpose, there may be used the so-called "transfer coating" devices which incorporate, in particular, 2 superimposed rollers: the function of the lower roller, which dips into the coating bath in which the subject compositions are present, is to impregnate the upper roller with a very thin layer, and the function of the latter roller is to then deposit onto the paper the desired amounts of the compositions with which it is impregnated, such proportioning of amounts being achieved by adjustment of the respective speed of the two rollers which rotate in directions opposite to one another.
The diluted compositions, namely, those comprising a solvent, can be applied by means of devices used on industrial machines for coating paper, such as the engraved "Mille point" roller and machines for the so-called reverse roll system. Once deposited on the supports, the compositions are hardened in a few seconds by passage through tunnel furnaces heated to 60°-200° C., the residence time in these furnaces varying typically from 2 to 30 seconds. This time depends, for a given oven length, on the speed at which the coated supports travel (this speed can exceed 200 meters per minute); generally, a support consisting of cellulose material circulates faster (for example, at a speed of 3 m/second for a temperature above 140° C.) than a plastic-based support. In fact, this latter cannot withstand the effects of high temperatures and it is therefore subjected to a lower temperature, but for a longer period, for example, it will travel at a speed of 0.75 m/second for a temperature on the order of 80° C.
The amounts of the compositions deposited onto the supports are variable, and range most frequently from 0.1 to 5 g/m 2 of surface treated. These amounts depend upon the nature of the supports and the non- or anti-stick properties desired. Such amounts most advantageously range from 0.5 to 1.5 g/m 2 for non-porous supports.
The compositions can also comprise a cycloorganopolysiloxane compound having vinyl and methyl groups, preferably in the form of a tetramer such as, for example, 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane.
The compositions according to the invention advantageously also comprise, per 100 parts by weight of the organopolysiloxanes (1) and the organohydropolysiloxanes (2), from 1 to 20 parts by weight of a linear polysiloxane which performs the function of coupling agent or chain lengthener and which comprises an organosiloxane containing 2 hydrogen atoms bonded to silicon per molecule, no silicon atom having more than one hydrogen atom bonded to it, and the 2 hydrogen atoms preferably being attached to the terminal silicon atoms of the siloxane, the organic radicals of such organosiloxane being selected from among the methyl, ethyl, phenyl and 3,3,3-trifluoropropyl radicals.
Exemplary catalysts are complexes of a platinum group metal, especially the platinum-olefin complexes as described in U.S. Pat. Nos. 3,159,601 and 3,159,662, the products of reaction of platinum derivatives with alcohols, aldehydes and ethers described in U.S. Pat. No. 3,220,972, the platinum-vinylsiloxane catalysts described in French Pat. No. 1,313,846 and its patent of addition thereto, No. 88,676, and French Pat. No. 1,480,409, and also the complexes described in U.S. Pat. Nos. 3,715,334, 3,775,452 and 3,814,730, and a rhodium-containing catalyst such as that described in U.S. Pat. Nos. 3,296,291 and 3,928,629.
The preferred metals of the platinum group are platinum and rhodium, with ruthenium also falling within this category although less active, since it is less costly.
The inhibitors according to the invention give particularly desirable results with platinum-vinylsiloxane complexes, especially the complex with 1,3-divinyl-1,1,3,3-tetramethyldisiloxane, and with platinum-methylvinylcyclotetrasiloxane complexes, especially the platinum-1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane complex.
The amount of catalyst complexes and of inhibitor to be added depends in particular upon the compositions, the type of catalyst and the application intended, and those skilled in this art can readily determine this amount. For coating compositions, the catalyst content typically ranges from about 5 to 1,000 ppm, and preferably from 20 to 100 ppm (calculated as the weight of the previous metal).
The amount of inhibitor typically ranges from 0.01 to 3%, and for the solvent-free coating compositions it preferably ranges from 0.05 to 2% relative to the total weight of the composition.
It has also been determined according to the invention that very small amounts of inhibitor enable the pot life to be exceptionally prolonged in solvent-free compositions intended for the anti-adherence treatment of paper, without thereby adversely affecting the hardening time of the composition when hot, these compositions being maintained at ordinary ambient temperature, namely, below 40°-45° C. and preferably below 25° C.
The cross-linking reaction which typically takes place at from 60° to 130° C., and preferably from 90° to 110° C., can be initiated or even carried out to completion by means of infra-red lamps or using a microwave oven or by U.V. irradiation, but in any event a forced-air oven can be used.
Within the scope of the present invention, any inhibitor (4) can be used which corresponds to the general definition given above, and particularly the organosilicon derivatives.
The inhibitors according to the invention advantageously have the general formula (A): ##STR5## in which n is an integer ranging from 0 to 10, preferably ranging from 1 to 5, R is a linear or branched chain alkyl radical having from 1 to 10 carbon atoms, an alkenyl radical having from 2 to 4 carbon atoms, a phenyl radical, a cycloalkyl radical having from 4 to 8 carbon atoms, an organosilyl radical selected from among the trialkylsilyl and trialkoxysilyl radicals in which the alkyl moiety has from 1 to 4 carbon atoms or a halogen atom selected from among chlorine, bromine and iodine, and R' is a hydrogen atom, an alkyl radical having from 1 to 4 carbon atoms, an α-hydroxyalkyl radical having from 1 to 4 carbon atoms, an alkylcarbonyl radical in which the alkyl moiety contains from 1 to 6 carbon atoms, a benzoyl radical, a benzoylalkyl radical in which the alkyl moiety contains from 1 to 6 carbon atoms, and an organosilyl radical selected from among the trialkylsilyl and trialkoxysilyl radicals in which the alkyl moiety has from 1 to 4 carbon atoms.
The inhibitors which are even more preferred according to the invention are those which have a genuine alkyne structure and which correspond to the general formula (B): ##STR6## in which n denotes an integer ranging from 1 to 15, preferably from 3 to 10 and X denotes a halogen atom selected from among the chlorine, bromine and iodine atoms.
Compounds having the formulae (A) and (B) are generally known materials, the synthesis of which is, for example, described in French Pat. No. 1,324,312, in M. Barrelle and R. Glenat, Bulletin de la Societe Chimique de France, No. 2, p. 453 (1967), in E. R. Jones, Journal of Chemical Society, p. 39 (1946) and Birkofer, Chem. Ber., volume 96, p. 3280 (1963). In the case where the products corresponding the the formulae (A) and (B) are new compounds, those skilled in the art will have no difficulty in the synthesis thereof by applying the processes described in the four references mentioned above.
Such inhibitors are preferably selected from among the following compounds: ##STR7##
In order to further illustrate the present invention and the advantages thereof, the following specific examples are given, it being understood that same are intended only as illustrative and in nowise limitative.
EXAMPLE 1
A treatment bath was prepared according to the following procedure:
(1) 100 parts of a silicone composition were used, which comprised:
(a) 90.5% of a polydimethylsiloxane copolymer having vinyl units in the chain and a dimethylvinylsiloxy end-group, including approximately 3% by weight of vinyl groups and possessing a viscosity of approximately 250 mPa.s at 25° C.;
(b) 2.5% of 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane; and
(c) 7% of a polymethylhydrosiloxane fluid having a trimethylsiloxy end-group, used as a cross-linking agent and containing approximately 1.5% by weight of hydrogen atoms bonded to silicon and having a viscosity of approximately 20 mPa.s at 25° C.
To this composition were added:
(2) 60 ppm of platinum (3×10 -4 gram-atom of Pt per kg of composition) in the form of a platinum complex prepared from chloroplatinic acid and 1,3-divinyl-1,1,3,3-tetramethyldisiloxane, as described in U.S. Pat. No. 3,814,730; and
(3) 0.5% by weight of 1-octyn-3-one, equivalent to 4.1×10 -2 mole/kg of composition.
The mixture was vigorously stirred at ambient temperature for a few minutes and this mixture was then, in the absence of solvent, deposited onto a paper sheet (approximately 1 g of mixture per m 2 ) by means of a coating rod, and the silicone composition was hardened in a forced-air circulation oven maintained at 110° C.
The hardening or curing of the silicone coating was thus evaluated by noting the minimum residence time in the oven required to obtain a fully-hardened coating. The increase in viscosity over time was also measured for the composition of the catalyzed bath, to judge the efficiency of the α-acetylenic ketones as inhibitor. The results are reported in the Table I which follows.
EXAMPLES 2 to 10
The procedure of Example 1 was repeated, except that a different inhibitor was selected; the results are reported in Table I below:
TABLE I______________________________________ Concentration of the Hardening inhibitor in the resin time at Gelation timeNature of % by 110° C. at 20° C. in hthe inhibitor weight mole/kg (sec) and min______________________________________none none none 10 30 min1-octyn-3-one 0.25% 2.1 × 10.sup.-2 10-12 7 h1-octyn-3-one 0.50% 4.1 × 10.sup.-2 10-12 14 h1-octyn-3-one 0.63% 5.0 × 10.sup.-2 12 25 h8-chloro-1- 0.22 1.4 × 10.sup.-2 15 4 hoctyn-3-one8-chloro-1- 0.50 3.0 × 10.sup.-2 15 10 hoctyn-3-one8-chloro-1- 0.68 4.1 × 10.sup.-2 15 19 hoctyn-3-one8-chloro-1- 0.73 4.6 × 10.sup.-2 18 24 hoctyn-3-one2-hydroxy-3- 0.50 4.5 × 10.sup.-2 15 60 hhexyn-4-one1-trimethyl- 0.70 5.6 × 10.sup.-2 10 3 hsilyl-1-butyn-3-one1-trimethyl- 1.37 9.8 × 10.sup.-2 15 18 hsilyl-1-butyn-3-one1-acetyl-1- 0.30 2.0 × 10.sup.-2 10 1 hoctyne1-acetyl-1- 1.50 9.8 × 10.sup.-2 10 3 h, 30 minoctyne1-phenyl-1- 0.30 2.0 × 10.sup.-2 15 1 hbutyn-3-one1-phenyl-1- 1.00 7.0 × 10.sup.-2 10 5 hbutyn-3-one1-trimethyl- 0.92 5.1 × 10.sup.-2 10 4 hsilyl-4,4-dimethyl-1-pentyn-3-one1-trimethyl- 1.40 7.7 × 10.sup.-2 10 6 h, 30 minsilyl-4,4-dimethyl-1-pentyn-3-one1-trimethyl- 2.50 14.0 × 10.sup.-2 15 21 hsilyl-4,4-dimethyl-1-pentyn-3-one1-trimethyl- 0.57 2.9 × 10.sup.-2 10 2 h, 45 minsilyl-2-benz-oylacetylene1-trimethyl- 1.51 7.5 × 10.sup.-2 15 9 hsilyl-2-benz-oylacetylene1-trimethyl- 2.10 10.4 × 10.sup.-2 15 25 hsilyl-2-benz-oylacetylene______________________________________
EXAMPLE 11
To the silicone composition of Example 1 were added 60 ppm of rhodium in the form of a bis(ethylene)rhodium acetylacetonate complex (C 2 H 4 ) 2 Rh(CH 3 COCHCOCH 3 ), described in U.S. Pat. No. 3,928,629, and 0.4% of 1-octyn-3-one.
(i) Hardening time at 110° C.: 20 seconds
(ii) Gelation time at 20° C.: 9 hours
(iii) Gelation time at 20° C. without inhibitor: 30 minutes
EXAMPLE 12
In this example, a composition was used which was identical to that of Example 1, except that it included 0.6% by weight of the inhibitor 8-chloro-1-octyn-3-one. This composition was applied, in the proportion of 0.8 g/m 2 , in a uniform layer onto one side of a Kraft paper weighing 67 g/m 2 (prepared from a pulp beaten to a freeness of 70° Shopper), surface-coated with a barrier layer of carboxymethylcellulose and supercalendered. The deposition of the layer was carried out by means of a coating head of the transfer coating type, mounted on an industrial paper-coating machine. The deposited layer was hardened by passing the coated paper at the speed of 180 m/minute into a tunnel furnace of the machine, adjusted to 110° C., the time of passage of the paper being 15 seconds.
On the side of the paper covered with a thin coating of hardened silicone, there were deposited, by means of a casting unit, 60 g/m 2 of a 40% strength solution in ethyl acetate of an adhesive acrylic polymer marketed under the trademark SOLURON A 1030 E. The paper covered with the adhesive solution was placed for 3 minutes in a ventilated oven adjusted to a temperature of 130° C., and was maintained for 15 minutes at room temperature. A layer of 24 g/m 2 of adhesive remained on the paper.
Onto this layer was next applied a polyethylene terephthalate film. This was maintained in place for 24 hours under a pressure of 24 g/cm 2 . After this time, the force needed to peel the film from the paper was measured; the peeling was carried out by means of a dynamometer, one of the two jaws of which was fixed, which held the paper, and the other pulled on one end of the film, which was folded back over 180° , at a rate of 25 cm/minute. A low peel strength was determined; 2.0 g for a film width of 1 cm.
In addition, the viscosity of the bath used for the coating varied from 300 mPa.s to 400 mPa.s over 7 hours. Gelation only occurred 24 hours after the introduction of the platinum catalyst into the composition.
EXAMPLE 13
The same composition was used as in Example 7, except that the catalyst was the reaction product of chloroplatinic acid with octanol, according to U.S. Pat. No. 3,220,972, the quantity of platinum being maintained at 60 ppm of platinum metal.
Exactly the same test was carried out as in Example 7, and a peel strength of 2 g for a 1 cm film width was also determined.
In addition, the viscosity of the bath used for the coating varied from 280 mPa.s to 450 mPa.s over 7 hours. Gelation only occurred 24 hours after the introduction of the platinum catalyst into the composition.
EXAMPLES 14 TO 20
To 100 g of polydimethylsiloxane oil having a viscosity of 600 mPa.s at 25° C. and comprising a dimethylvinylsiloxy end-group (0.4% by weight of vinyl groups) were added 41.5 g of fumed silica having a specific surface of 300 m 2 /g, surface treated with hexamethyldisilazane. To this paste was added an organosilicon composition containing 4 g of a polydimethylsiloxane copolymer containing hydromethylsiloxy units in the polymer chain (0.24% by weight of hydrogen atoms bonded to silicon) and containing approximately 120 silicon atoms per molecule and 4 g of a polydimethylsiloxane polymer comprising dimethylhydrosiloxy end-groups, having a viscosity of 30 mPa.s at 25° C.
To this composition were added a platinum-based catalyst and an inhibitor which was 8-chloro-1-octyn-3-one.
In Examples 14 to 16, the catalyst employed was the same as that employed in Example 13. In Examples 17 to 20, the catalyst employed was the same as in Example 1.
Cross-linking time was ascertained by hand, by feel of a 500 μm thick film of the composition which was coated onto polyethylene-coated paper.
The results are reported in Table II which follows:
TABLE II__________________________________________________________________________Inhibitor Bathconcentration Platinum Crosslinking time stabilityExamples% concentration 120° C. 150° C. ("pot life")__________________________________________________________________________14 0.096 12 ppm -- 1 min 16 days15 0.066 12 ppm -- 1 min 3 days16 0.19 6 ppm -- 1 min, 30 sec >1 month17 0.096 12 ppm -- -- >1 month18 0.066 12 ppm 1 min, 30 sec 1 min 21 h19 0.082 6 ppm 1 min, 30 sec 1 min 1 month20 0.053 6 ppm 1 min, 30 sec 1 min 5 days__________________________________________________________________________
While the invention has been described in terms of various preferred embodiments, the skilled artisan will appreciate that various modifications, substitutions, omissions, and changes may be made without departing from the spirit thereof. Accordingly, it is intended that the scope of the present invention be limited solely by the scope of the following claims. | Curable organopolysiloxane compositions useful, e.g., for the production of anti-stick coatings, comprise (1) an organopolysiloxane, (2) an organohydropolysiloxane, (3) a platinum group metal hardening catalyst, and (4) a platinum catalysis inhibitor comprising an acetylenic α-ketone in an amount which inhibits gelation at ambient temperatures but does not prevent cross-linking at temperatures in excess thereof. | 2 |
BACKGROUND AND SUMMARY OF THE INVENTION
The present invention relates to wood burning stoves of the airtight variety, although in one operational mode of the invention, the stove can be used to burn coal.
In recent years, due primarily to the energy crisis, wood burning stoves have enjoyed an ever-increasing popularity and public acceptance. The ultimate objective in stoves of this type is to achieve as complete combustion as possible of the combustion gases, since with more efficient combustion, burn time can be increased because it is possible to slow the fire down and still obtain the desired heat transfer for maximum comfort. However, most existing stoves of this type, i.e. airtight wood burning stoves, have a combustion efficiency somewhere in the range of fifty to sixty percent, primarily due to the fact that the ignition point of combustion gases is in the general range of 1300° F. whereas the temperatures generated in stoves of this type are usually in the range of 500° and 900° F. Thus, efficient combustion of these combustion gases has been difficult, if not impossible, to achieve, resulting in lower combustion efficiency, which in turn results in creosote build-up in the chimney or flue, which build-up frequently results in chimney fires. Also, reduced combustion efficiency results in undesirable smoke pollution.
In co-pending U.S. application Ser. No. 136,687, filed Apr. 2, 1980 by Peter S. Albertsen, one of the co-inventors of this application, the concept of using a catalytic converter in stoves of this type of obtain greatly increased combustion efficiency is disclosed. Specifically, by causing the combustion gases to flow through a catalytic converter before reaching the exhaust duct or flue of the stove, the ignition point of the escaping combustion gases is lowered to the general range of 500° F., thus resulting in almost complete afterburn of these gases in the normal range of operating temperatures in stoves of this type. This results in combustion efficiency in the general range of ninety percent, or in other words, an efficiency of approximately thirty-five percent more than that achieved by traditional airtight woodburning stoves. This increased efficiency means little or no pollution will enter the atmosphere because the smoke, a normal by-product of conventional wood stoves, is virtually eliminated, leaving a harmless humid vapor in its place. In addition, as a result of the almost perfect combustion that takes place, there is virtually no creosote build-up in the chimney, thus greatly reducing chimney fire hazards and at the same time reducing chimney maintenance. Furthermore, peak performance can be obtained even with the use of soft and unseasoned wood and burn time can be increased because it is possible to slow the fire down and still maintain almost perfect combustion while transferring heat temperatures necessary for maximum comfort.
The present invention is also directed to the use of catalytic converters in wood stoves, and is particularly directed to an improved baffle system used in connection therewith. More specifically, as suggested in the aforesaid co-pending Albertsen application, it is desired to have all of the combustion gases pass through the catalytic converter when the stove is in its normal operating mode. However, since the catalytic converter is in the nature of a filter which to some degree resists or impedes the flow of combustion gases therethrough, it will be apparent that when the access door of the stove is opened, the combustion gases and smoke would follow the path of least resistance and would billow outwardly through the open access door. In order to prevent this, the co-pending Albertsen application discloses damper means which, when the access door of the stove is opened, automatically move by gravity to a position permitting direct access to the exhaust duct or flue of the stove, so that the combustion gases and smoke will be exhausted through the flue, rather than spilling into the room through the open access door.
The present invention achieves these same basic objectives by an improved damper system. Specifically, the damper of the present invention is manually controlled, rather than gravity controlled, thus eliminating the possibility of the damper inadvertently jamming or sticking in closed position when the access door of the stove is opened. In order to insure that the damper moves to its proper position when the access door of the stove is opened, handle means for manually manipulating the damper from outside the stove are provided, said handle means physically preventing the access door of the stove from opening until said handle means is moved to a predetermined position, said predetermined position regulating the damper so that flow of the combustion gases through the converter is blocked, and direct flow of the combustion gases to the stove exhaust is opened. Thus, in the present invention, the access door of the stove cannot be opened until the damper has positively been moved to its proper position.
In addition, with the stove in its normal operating mode, i.e. with the door of the stove closed and with combustion gases passing through the catalytic converter, the possibility exists that the catalytic converter may on occasion become blocked or clogged, primarily due to the burning of improper materials in the stove. Should this happen, there would be no place for the combustion gases and smoke to go, and hence said gases and smoke would force themselves out through the front opening of the stove, notwithstanding the fact that the access door is in closed position. This, of course, would result in undesirable smoke spillage into the room in which the stove is located. In order to prevent this, the damper of the present invention has been specifically designed with a controlled leakage factor, i.e. controlled leakage through the damper to the exhaust duct is possible, even when the damper is closing off the access opening to said duct. As a result of this built-in controlled leakage, should the catalytic converter become blocked or clogged, combustion gases and smoke still can pass through the closed damper to the exhaust duct, rather than spilling into the room around the door of the stove. This is an important feature of the present invention.
In addition, the damper system of the present invention permits the stove to assume an operational mode where coal can be burned instead of wood. This is not possible in the aforesaid co-pending Albertsen application.
Other objects, features and advantages of the invention shall become apparent as the description thereof proceeds when considered in connection with the accompanying illustrative drawings.
DESCRIPTION OF THE DRAWINGS
In the drawings which illustrate the best mode presently contemplated for carrying out the present invention:
FIG. 1 is a front elevational view of one form of stove embodying the present invention;
FIG. 2 is an enlarged section on line 2--2 of FIG. 1;
FIG. 3 is an enlarged fragmentary section on line 3--3 of FIG. 1 showing the stove in its normal operational mode;
FIG. 4 is a view similar to FIG. 3 but showing the damper in the position it assumes when the door of the stove is opened;
FIG. 5 is a fragmentary sectional view of a slightly modified construction;
FIG. 6 is a front elevational view of a fireplace insert type stove embodying the present invention;
FIG. 7 is a top plan view thereof;
FIG. 8 is an enlarged fragmentary section taken on line 8--8 of FIG. 6; and
FIG. 9 is a view similar to FIG. 8 but showing the position of the damper when the door is free to be opened.
DESCRIPTION OF THE INVENTION
Referring now to the drawings, and more particularly to FIG. 1, there is shown generally at 10 a stove comprising a front wall 12, top wall 14, side walls 16, rear wall 18 and bottom wall 20 defining a generally complete enclosure. The stove 10 may be fabricated from any suitable sheet metal or may be of cast iron. A plurality of supporting legs 22 depend from the bottom wall 20, as is conventional.
The front wall 12 of the stove is provided with an access opening 24 covered by a door 26 hingedly mounted as at 28 whereby the door may be swung to an open position when it is desired to gain access to the stove interior for any reason. A conventional handle and latch assembly 30 is provided to facilitate opening movement of the door and to maintain the door latched in its closed position.
A horizontal partition 32 located in spaced substantially parallel relation to top wall 14 but generally adjacent thereto defines a pair of interior chambers, namely, a relatively large primary combustion chamber 34 located below the partition and a relatively small afterburn chamber 36 located above the partition. As will be seen most clearly in FIG. 3, partition 32 is provided with a pair of circular openings 38 and 40. In addition, partition 32 has mounted thereon a catalytic converter 42, the details of which form no part of the instant invention, although it will be understood that converter 42 generally comprises a ceramic honeycomb having a thin metallic coating that acts as a catalyst to combustion gases. Specifically, the catalytic effect reduces the normally high ignition point of escaping combustion gases from their normal high range of approximately 1300° F. to a catalyzed average range of approximately 500° F., thus allowing for substantially complete burning of these gases, since the normal operating temperatures of wood burning stoves is in the range of 500° to 900° F. As will be noted, the converter 42 completely covers opening 38 whereby all combustion gases passing upwardly through the opening 38 must pass through converter 42. A viewing port 44 is provided in top wall 14 in registry with the converter 42 whereby the radiant state of the catalytic converter may be visually evaluated in order to permit draft controls 46, 48 communicating with chamber 34 to be adjusted for maximum operating efficiency of the stove. An exhaust duct or flue 50 communicates with afterburn chamber 36.
Referring to FIGS. 2 through 4, it will be seen that damper means in the form of plate 52 is slidably mounted on the underside of partition 32. Specifically, a pair of trackways 54 are secured to the inner surface of side wall 16 for sidably supporting damper 52 whereby the latter may be moved between a first position in which it covers opening 40, as illustrated in FIG. 3, and a second position wherein it covers opening 38 and unblocks opening 40, as illustrated in FIG. 4. Stop means in the form of a small abutment 56 is secured to the underside of partition 32 to limit the travel of damper 52 and to insure that when the damper 52 has been moved to the position illustrated in FIG. 4, it will be in proper registry with opening 38 so as to cover same. Movement of damper 52 between the positions illustrated in FIGS. 3 and 4 is manually achieved by means of an elongated rod 58 secured at its inner end as at 60 to damper 52 and extending outwardly through opening 62 provided in front wall 12 just above the top of door 26. At its outermost extremity, the rod 58 has a downwardly bent portion 64 terminating in a knob or handle 66. As will be clearly seen in FIG. 3, when damper 52 is in its innermost position, i.e. covering the opening 40, the downwardly bent portion 64 and knob 66 physically block opening movement of door 26. Thus, before the door 26 can be opened, rod 58 must be retracted to the position illustrated in FIG. 4, whereupon opening 40 becomes unblocked, and opening 38 becomes blocked. For reasons which will hereinafter become apparent, damper 52 is provided with a relatively small aperture or opening 68.
The operation of stove 10 is as follows. With the rod 58 in the retracted position illustrated in FIG. 4, the door 26 is free to open to permit loading of the stove with a supply of wood. After the wood has been set on fire, the door 26 is closed, but the rod 58 is retained in the retracted position illustrated in FIG. 4 so that for a period of time the opening 40 remains unobstructed. This facilitates starting of the fire by increasing the draft, it being understood that when the damper is in the position illustrated in FIG. 3, the draft is reduced due to the inherent resistance of converter 42 through which the combustion gases must flow. Accordingly, in order to increase the draft when the fire in the stove is being started, the damper is retained in the FIG. 4 position for a period of time, or until the fire has really taken hold. At the same time, the draft controls 46 and 48 are regulated to achieve the desired air intake into combustion chamber 34 to initiate and maintain proper burning therein. Once the fire in combustion chamber 34 is going strongly, the rod 58 is moved inwardly to the position illustrated in FIG. 3, wherein damper 52 now covers or blocks opening 40, whereby the flow of combustion gases to afterburn chamber 36 is necessarily through the catalytic converter 42. As previously explained, the converter 42 reduces the ignition point of the combustion gases passing therethrough so that almost complete combustion of the latter takes place, thereby eliminating the passage of smoke to exhaust duct 50 whereby resulting pollution is almost completely eliminated. Also, due to the almost complete burning of the combustion gases prior to entering the flue or exhaust duct 50, there is virtually no creosote build-up in the flue or associated chimney, thus greatly reducing chimney fire hazards and reducing maintenance. If, however, the door 26 of the stove could be opened with the damper in the position illustrated in FIG. 3, the smoke and combustion gases in chamber 34 would follow the path of least resistance and would billow outwardly through the opened door. In order to prevent this from happening, door 26 cannot be opened until rod 58 has been retracted to the position illustrated in FIG. 4, in which position the downwardly bent end portion 64 and handle or knob 66 no longer obstructs opening of the door. As will be apparent, when rod 58 is moved to this position, the damper 52 automatically moves to a position wherein it blocks converter 42 and unblocks opening 40, whereupon smoke and combustion gases from combustion chamber 34 will pass through opening 40 to exhaust duct or flue 50 rather than flowing out the front of the stove.
On some occasions the catalytic converter 42 may become blocked or clogged primarily due the burning of improper materials in the stove. Should this happen while the stove is in its normal operating mode, i.e. as illustrated in FIG. 3, there would normally be no place for the combustion gases and smoke to go and hence said gases and smoke would force their way out around the closed door 26, thus resulting in undesirable smoke spillage into the room in which the stove is located. In order to prevent this from happening, an important feature of the present invention is the provision of means permitting controlled leakage of combustion gases and smoke through opening 40, even when damper 52 is in the position illustrated in FIG. 3. The controlled leakage means may take the form of a relatively small opening, such as the opening 68 in damper 52, whereupon when the damper is in the position illustrated in FIG. 3, the flow of combustion gases will still be through converter 42 since this path offers less resistance than the relatively small aperture 68, but on the other hand, should the converter 42 become blocked or clogged, the aperture 68 does provide a path through which the combustion gases and smoke may pass to duct 50, rather than being forced out through the front of the stove. It will be understood that the leakage means need not necessarily take the form of aperture 68, but rather the desired leakage could also be achieved by having a loose or sloppy seal between damper 52 and partition 32 when the former is in the position illustrated in FIG. 3.
If it is desired to burn coal in stove 10, the catalytic converter must be bypassed because the sulfur in the coal fumes would be detrimental to the converter and would destroy same. Thus, when coal is being burned, the damper 52 is moved to the position illustrated in FIG. 4 to substantially block access to the catalytic converter, whereupon the combustion gases and fumes from the burning coal would pass directly through opening 40 to exhaust duct 50. Of course, the door 26 would be maintained in closed position, even though the rod 58 remains in the retracted position of FIG. 4.
FIG. 5 illustrates a modification to the stove shown in FIGS. 1 through 4, which modification is specifically designed to improve operation of the stove when burning coal. Specifically, in the form of the invention illustrated in FIG. 5, the catalytic converter 42 is slidably mounted on partition 32 for movement from the full line position illustrated to the broken line position. Specifically, a rod 70 is secured at its inner end to converter 42, as at 72, said rod extending through an opening 74 in front wall 12, it being noted that the opening 74 is located slightly above the opening 62. Rod 70 terminates at its outer extremity in a handle or knob 76 whereupon manipulation of rod 70 from the full line to broken line position thereof causes corresponding movement of converter 42 from its full line to its broken line position. A substantially horizontally extending plate 78 is secured to and extends from front wall 12 whereupon when converter 42 has been moved to its inoperative or broken line position, as illustrated in FIG. 5, the plate 78 functions to define a cover for the top of the converter, whereupon the converter is protected both at its top and bottom from exposure to coal fumes in the stove, it being understood that the only time converter 42 is moved to its inoperative or broken line position, as illustrated in FIG. 5, is when stove 10 is being used to burn coal. Of course, in the embodiment illustrated in FIG. 5, it is not necessary to retract the rod 58 when burning coal, because opening 38 becomes completely unobstructed when converter 42 is moved to its broken line position, and hence provides the necessary communication with chamber 36.
FIGS. 6 through 9 illustrate application of the present invention to a fireplace insert stove shown generally at 80. Aside from obvious cosmetic differences, the only real difference between stove 10 and stove 80 is that the latter has a much more shallow afterburn chamber 82 thus necessitating that the catalytic converter 84 be mounted on the underside of horizontal partition 86, as illustrated most clearly in FIGS. 8 and 9. Opening 88, in registry with the converter 84, and opening 90 in partition 86 correspond to the aforedescribed openings 38, 40 respectively. Damper 92 and manipulating rod 94 correspond with and operate in an identical manner to aforesaid damper 52 and rod 58. As stated, the only real difference from a functional standpoint between stoves 80 and 10 is that because of the relatively shallow afterburn chamber 82 in the former, the catalytic converter depends from the horizontal partition member, rather than being located on the top side thereof. By the same token, in this form of the invention, the damper means slides along the top surface of the partition, rather than along the underside thereof, as in stove 10. Doors 96 in the stove 80 cannot be swung to open position until rod 94 has been retracted to the position illustrated in FIG. 9, at which point the passage of combustion gases and smoke through the catalytic converter is blocked by damper 92, thus causing the combustion gases and smoke to flow through opening 90 to exhaust duct 98 whenever the doors 96 are opened. The one disadvantage of the stove illustrated in FIGS. 6 through 9 is that it cannot be used to burn coal, since the exposure of the catalytic converter 84 to the coal fumes would quickly destroy the converter.
While there is shown and described herein certain specific structure embodying the invention, it will be manifest to those skilled in the art that various modifications and rearrangements of the parts may be made without departing from the spirit and scope of the underlying inventive concept and that the same is not limited to the particular forms herein shown and described except insofar as indicated by the scope of the appended claims. | A wood burning stove having a catalytic converter for achieving greatly increased combustion efficiency, said stove having damper means for insuring that all combustion gases from the primary combustion chamber pass through said converter before reaching the stove's exhaust duct when the damper is in one position, and manual control means for moving the damper to a second position wherein the combustion gases bypass said converter and pass directly to said exhaust duct, it being necessary to move said damper to its second position before the door of said stove can be opened. Said damper has a controlled leakage factor whereby if the converter becomes clogged when the damper is in its first position, combustion gases will be permitted to pass to said exhaust duct. In one operational mode, the stove may be used to burn coal. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a comparator.
2. Related Background Art
FIG. 3 shows an example of a circuit of a conventional comparator. V 3 denotes a reference voltage source; I 7 indicates a constant current source; Q 21 to Q 25 transistors; and R 1 and R 2 resistors.
A circuit which is constructed by the constant current source I 7 and the transistors Q 21 to Q 24 is a simple comparator. An input terminal IN and the resistor R 2 are connected to a base of the transistor Q 21 and a base of the transistor Q 25 through wires and connectors from another electronic circuit board, respectively.
The operation of the comparator of FIG. 3 will now be described hereinbelow.
In the case where the input terminal IN and the resistor R 2 are respectively connected to the above transistors Q 21 and Q 25 , the transistor Q 25 is turned off and the circuit operates as an ordinary comparator.
When the terminal IN and the resistor R 2 are not connected, an output of the comparator is an output in a state in which a high level signal has been applied to an input. In this state, if a problem logically occurs, the transistor Q 25 connected by the resistor R 1 is set into a saturation state by a power source V cc , thereby fixing a base potential of the transistor Q 21 to a low level and satisfying the logic.
The conventional comparator, however, has the following technical problems to be solved.
(1) Since the wires or connectors must be added to know the coupling state, the costs rise.
(2) Since the wires or connectors are needed to know the coupling state in addition to a purpose of the input of the comparator, it is impossible to know the coupling states of both of them. Then a disconnection to each wire or a damage of the connector occurs, the normal operation cannot be performed and there is a fear of malfunction.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a comparator which can solve the foregoing problems.
Another object of the invention is to provide a comparator comprising transistors to control the state of an input terminal and a control circuit to enable the transistors in a high impedance input state.
According to the invention, the high impedance input state can be detected by the above construction without additionally providing any wire and connector.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a circuit diagram of a comparator according to an embodiment of the invention;
FIG. 2 is a circuit diagram of a comparator according to another embodiment of the invention; and
FIG. 3 is a circuit diagram of a conventional comparator.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a circuit constructional diagram showing most preferably a feature of the invention. In FIG. 1, V 1 denotes a reference voltage source; I 1 to I 3 indicate constant current sources; and Q 1 to Q 10 indicate transistors.
A circuit which is constructed by the constant current source I 2 and the transistors Q 4 to Q 7 is a comparator. Current mirror circuits are constructed by the transistors Q 2 and Q 3 and the transistors Q 8 and Q 9 . The constant current source I 1 and the transistor Q 1 supply a constant current to the current mirror circuit. The constant current source I 3 and the transistor Q 10 supply a constant current to the current mirror circuit.
It is now assumed that the transistors Q 1 , Q 4 . Q 5 , and Q 10 are equal PNP transistors and that the transistors Q 2 , Q 3 , Q 8 , and Q 9 are equal NPN transistors. There are the relations of I 1 =I 3 and I 1 >I 2 among the constant current sources I 1 to I 3 .
The operation of the comparator of FIG. 1 will now be described hereinbelow.
In the case where some input exists at the input terminal IN which is connected to a base of the transistor Q 4 , a collector of the transistor Q 3 current of the transistor Q 1 from the base of the transistor Q 4 and the terminal IN. At this time, the circuit operates as an ordinary comparator.
The operation in a disconnected state of the input terminal IN, which is a problem in the conventional comparator, in the case of the embodiment will now be described. When no input exists at the input terminal IN, the collector of the transistor Q 3 tries to pull in all of the currents which are equivalent to the base current of the transistor Q 1 from the base of the transistor Q 4 . Since the relation between the constant current sources I 1 and I 2 is now set to I 1 >I 2 , the, base current of the transistor Q 1 should equal the collector current of the transistor Q 3 according to the well known operation of current mirror circuitry. But the collector current of the transistor Q 3 cannot be greater than the base current of the transistor Q 4 . Since transistor Q 3 cannot pull in sufficient current from base of Q 4 to equal the base current of transistor Q 1 , the transistor Q 3 is set into the saturating state. A base potential of the transistor Q 4 , therefore, is determined by a voltage between the collector and the emitter of the transistor Q 3 and is fixed to a low level.
FIG. 2 is a circuit constructional diagram showing another embodiment of the invention. In FIG. 2, V 2 denotes a reference voltage source; I 4 to I 6 constant current sources; and Q 11 to Q 20 transistors.
A circuit which is constructed by the constant current source I 5 and the transistors Q 14 to Q 17 is a comparator. Current mirror circuits are constructed by the transistors Q 12 and Q 13 and the transistors Q 18 and Q 19 . The constant current source I 4 and the transistor Q 11 function as a constant current source which is supplied to the current mirror circuit. The constant current source I 6 and the transistor Q 20 function as a constant current source which is supplied to the current mirror circuit.
It is now assumed that the transistors Q 11 , Q 14 , Q 15 , and Q 20 are equal NPN transistors and that the transistors Q 12 , Q 13 , Q 18 , and Q 19 are equal PNP transistors. There are the relations of I 4 =I 6 and I 4 >I 5 among the constant current sources I 4 to I 6 .
The operation of the comparator of FIG. 2 will now be described hereinbelow.
In the case where some input exists at the input terminal IN which is connected to a base of the transistor Q 14 , a collector of the transistor Q 13 supplies a current which is equivalent to a base current of the transistor Q 11 to the base of the transistor Q 14 and the terminal IN. At this time, the circuit operates as an ordinary comparator.
In the case where no input exists at the input terminal IN, which becomes a problem in the conventional comparator, the collector of the transistor Q 13 tries to supply all of the currents equivalent of the base current of the transistor Q 11 to the base of the transistor Q 14 . Since the relation between the constant current sources I 4 and I 5 is set to I 4 >I 5 , the base current of the transistor Q 11 should equal the collector current of the transistor Q 13 according to the well known operation of current mirror circuitry. But the collector current of the transistor Q 13 cannot be greater than the base current of the transistor Q 14 . Since transistor Q 13 cannot supply sufficient current to the base of Q 14 to equal the base current of transistor Q 11 , the transistor Q 13 is set into the saturating state. Therefore, the base potential of the transistor Q 14 is determined by the voltage between the collector and the emitter of the transistor Q 13 and is fixed to a high level.
As described above, according to the embodiments, since none of the wires and connectors is additionally needed, the input disconnection state can be certainly known without increasing the costs. | A comparator comprises transistors to turn on/off an input terminal and a control circuit to enable the transistors in a high impedance input state. The high impedance input state can be detected by the above construction without additionally providing any wire and connector. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority to U.S. Provisional Application Ser. No. 60/740,263, filed Nov. 29, 2005, the entirety of which is hereby incorporated by reference.
TECHNICAL FIELD
[0002] The present invention relates to the field of race course design.
BACKGROUND OF THE INVENTION
[0003] Several sporting events involve competitors racing around an oval track consisting of two straightaway portions and two curved portions connecting the straightaway portions. FIG. 1A illustrates a traditional track 10 with straightaway portions extending from point 101 to 106 and point 103 to 104 and curved portions extending from point 101 to 102 to 103 and point 104 to 105 to 106 . A traditional track 10 often includes several parallel lanes where lane 1 is the innermost lane. FIG. 1B shows a portion of track 10 extending from point 106 to 101 to 102 . As can be seen in FIG. 1B , track 10 includes of 8 parallel lanes 131 - 138 . In several events utilizing track 10 , each competitor must stay within his or her assigned lane. At least twelve Olympic events require competitors to stay within an assigned lane: the 200 m and 400 m, the 400 m hurdles, the 4×100 m relay, the 4×400 m relay (first leg) and the decathlon, for men and for women. The arc length of an outer lane is greater than that of an inner lane. Thus, in order for each competitor to run the same length and yet finish at a common finish line, the competitors are placed in staggered starting position, for example, on the first curve between points 101 and 103 such that each competitor runs equal arc lengths before reaching the straightaway.
[0004] Despite this “staggered start” positioning that equalizes the distance run by each competitor, a serious lack of parity between competitors in track events remains. This lack of parity stems from the “centrifugal effect.” An athlete running a curve must expend some of his or her thrust force to combat the centrifugal force, leaving less thrust force available for increasing or maintaining speed. Consequently, he or she can run faster on a straight course than on a curve. More importantly, he or she can run faster in an outer (less curved) lane than in an inner lane. The importance of this effect is indicated by the fact that Tommy Smith's world record time for the conventional 200 m, which he set running in Lane 3 , is 0.43 sec slower than his world record time for a 200 m run in a straight track.
[0005] A 200 m straight track may be constructed by adding a 100 m extension onto the straightaway extending from point 103 to 104 of FIG. 1A . Such a 100 m extension may prove problematic within a track venue as it may not fit within the playing surface and may result in inferior sightlines for spectators.
BRIEF SUMMARY OF THE INVENTION
[0006] The present invention is directed to a system and method for conducting a more fair race around an oval track by configuring the track such that the runner in each lane runs an arc angle equal to the runners in other lanes. Such a configuration eliminates the disproportionate effect of centrifugal force on competitors running in inner lanes. Embodiments of the invention provide for the addition of a straight section to a standard oval track extending from the midpoint of a curved section and perpendicular to the existing straightaway section. Runners in each lane start at staggered locations on the straight section and proceed through a curved quadrant and to a finish line on the straightaway furthest away from the straight section. The staggered starting locations are chosen such that the runner in each lane travels an equal distance from the starting location to a common finish line on the straightaway. The straight section may have a rectangular shape in some embodiments or may be angled to accommodate the staggered starting positions such that the straight section extends further at lane 1 than at the outer lane.
[0007] In another embodiment, runners in each lane start at staggered locations on the straight section and proceed through a curved quadrant, the straightaway furthest away from the straight section, a curved semi-circular section, and then to a finish line on the straightaway closest to the straight section. Once again, staggered starting locations are chosen such that the runner in each lane travels an equal distance from the starting location to a common finish line on the straightaway. In one embodiment, the track may have straight sections extending from each curved section perpendicular to the straightaway sections and in opposite directions of each other such that a race covering half of the length of the oval track may be started from the first straight section and a race covering the entire length of the oval track may be started from the second straight section and both races may utilize a common finish line. In another embodiment, the track may have a single straight section such that races covering half the length of the oval track and races covering the entire length of the oval track finish on opposite straightaways when starting from the straight section.
[0008] The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. The novel features which are believed to be characteristic of the invention, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] For a more complete understanding of the present invention, reference is now made to the following descriptions taken in conjunction with the accompanying drawing, in which:
[0010] FIG. 1A illustrates a track configuration according to the prior art;
[0011] FIG. 1B illustrates a close-up on a quadrant of the track configuration of FIG. 1A according to the prior art;
[0012] FIG. 1C illustrates a track configuration according to one embodiment of the present invention;
[0013] FIG. 1D illustrates a close-up on a quadrant of the track configuration of FIG. 1C according one embodiment of the present invention;
[0014] FIG. 1E illustrates a track configuration according to one embodiment of the present invention;
[0015] FIG. 2 illustrates the relationship between speed, V, and time, T; and
[0016] FIG. 3 illustrates the thrust force components in running a curve.
DETAILED DESCRIPTION OF THE INVENTION
Three-parameter Model
[0017] The inherent discrepancy that results due to lane assignment may also be observed though the use of a three-parameter model of sprinting. This model may be used to simulate 200 m runs in different lanes. Changing one parameter value (constant but not maximal thrust force) allows simulation of 400 m runs in different lanes. This model derives from earlier models proposed in Joseph B. Keller, “A Theory of Competitive Running,” Physics Today 26(9) pp. 42-47 (1973) (“Keller), and in Igor Alexandrov and Philip Lucht, “Physics of Sprinting,” American Journal of Physics 49 pp. 254-257 (1981) (“Alexandrov and Lucht”), each of which is hereby incorporated by reference in its entirety. One of the parameters is the maximum thrust force that a runner can exert; this parameter also appears in Keller and Alexandrov and Lucht. The second parameter characterizes the resistive force on a runner, which is assumed to be proportional to the square of the speed; the assumption in Keller and Alexandrov and Lucht is that the resistive force is proportional to the speed itself. The third parameter is an “efficiency” coefficient that measures the runner's ability to provide maximum thrust force in exactly the right direction, while coping with the centrifugal effect on limbs and torso. There is no such term in Keller or Alexandrov and Lucht.
[0018] The analysis of sprinting is based on two equations of motion, one for a straight run and the other for a run on a curved track. The first equation is
ⅆ 2 x ⅆ t 2 = - β ( ⅆ x ⅆ t ) 2 + F ( 1 )
and the second is
ⅆ 2 x ⅆ t 2 = βκ V 2 { 1 - ( ⅆ x ⅆ t ) 4 ( β V 2 R n ) 2 } 1 / 2 - β ( ⅆ x ⅆ t ) 2 ( 2 )
[0019] These equations derive from earlier theories of Keller and Alexandrov and Lucht. The theories of Keller and Alexandrov and Lucht and their relationship to Eqs. (1) and (2) are explored further below. In Eqs. (1) and (2), x denotes distance and v=dx/dt denotes speed. V is the “terminal speed” on the straight, R n is the radius of the nth track lane and κ is an “efficiency” parameter (these three constants are discussed below).
[0000] The Thrust Force
[0020] The constant F is the maximum thrust force per unit mass; the definition of a sprint is that the maximum thrust is supplied throughout. This thrust force is generated by the runner pushing his or her feet against the track.
[0000] The Resistive Force
[0021] The first term on the right in Eq. (1) is the resistive force per unit mass. Both Keller and Alexandrov and Lucht assumed that the resistive force is proportional to the speed (−αv) rather than the squared speed (−βv 2 ) as in Eqs. (1) and (2). It is not worthwhile to debate this issue here because this discussion is limited to the case of constant thrust force, for which linear and quadratic resistive force laws yield virtually identical results. FIG. 2 illustrates the relationship between speed, V, and time, T, as determined by Eq. 3 for line 201 and Eq. A3 (below) for dotted line 202 . For lines 201 and 202 in graph 20 , V=10.753 m/sec and α is related to β based on the relationship of Eq. A6 (below). Also of note with regard to resistive forces, while air resistance is certainly a factor, the resistive force is also primarily a ground force reaction. When the runner's foot hits the track, it is brought to rest instantaneously by a frictional ground reaction force, which is the primary resistive force. This is abundantly clear if one watches a runner who has crossed the finish line and no longer exerts a thrust force. He or she is brought to a stop, not by air resistance, but by a series of ground reaction impulses.
[0000] Terminal Speeds
[0022] The first integral of Eq. (1), with initial condition v(0)=0, i.e., starting from rest, is
v = V tanh β Vt ; V = F β ( 3 )
[0023] The speed increases rapidly and approaches the terminal speed V asymptotically ( FIG. 2 ). The value of V in the second Eq. (3) may be found directly by setting dv/dt=0 in Eq. (1). The terminal speed V n for Lane n is found similarly by setting dv/dt=0 in Eq. (2). This leads to
V n = V { 1 κ 2 + 1 ( β R n ) 2 } - 1 / 4 ( 4 )
The Centrifugal Effect
[0024] Alexandrov and Lucht modeled the centrifugal effect on an athlete running a curved path. In addition to the acceleration dv/dt in the direction of motion, the runner experiences an acceleration component v 2 /R n directed toward the center of curvature. The thrust force must support this acceleration, i.e., must oppose the centrifugal force, if the runner is to stay in his or her lane. Consequently, the thrust force must be directed at an angle θ to the direction of motion, such that
F sin θ = v 2 R n ( 5 )
[0025] The thrust force component in the direction of motion is reduced to Fcosθ and substituting this for F in Eq. (1) leads to Eq. (2), with κ=1. FIG. 3 illustrates the thrust force components in running a curve as described herein.
[0000] The Radius of Curvature
[0026] Each lane of a typical running track consists of two parallel straight 100 m segments, capped at each end by semi-circular arcs as shown in FIG. 1A . The inner boundary of the inner lane (Lane 1 ) illustrated as lane 131 in FIG. 1B has semi-circular arc length 100 m, so that
R 1 = 100 m π ≈ 31.83 m ( 6 a )
Or more generally, for a track with a semi-circular arc of length L
R 1 = L π ( 6 b )
Each lane has width 1.22 m, so that
R n≈ {31.83+1.22( n− 1)} m (7a)
Or more generally, for a track with a semi-circular arc length L and lanes of width W
R n = { L π + W ( n - 1 ) } m ( 7 b )
System Parameter Values
[0027] Following Alexandrov and Lucht, measured world record times for the 100 m (10.1 sec) and straight 220 yards (19.51 sec) can be used to evaluate the system parameters β and F or, equivalently, β and V. It is assumed that the 220 yards time is equivalent to a time of 19.40 sec for 200 m. In view of the 100 m time, it may be assumed that the split times for the first and second halves of the 200 m were 10.1 sec and 9.30 sec, respectively. Since the second half was run at the terminal speed V, this gives the parameter value V=10.753 m sec −1 . The first Eq. (3), with v=dx/dt, integrates to
x = 1 β ln cosh β Vt ( 8 )
For times T for which the exponential exp(−βVT) is negligible, this gives
X ≈ VT - 1 β ln 2 ( 9 )
so that
β ≈ ln 2 VT - X ( 10 )
Substituting the measured 100 m time gives β=0.0805 m −1 .
Efficiency
[0028] Alexandrov and Lucht used their (linear resistive force) versions of Eqs. (1) and (2) to predict a record time for the conventional (curved) 200 m. Their predicted time of 19.68 sec compared to the measured time of 19.83 sec represents an under-estimation of the centrifugal effect; the difference between the measured straight and curved track times is 0.43 sec but their predicted difference is only 0.28 sec. Not surprisingly (see below), use of Eqs. (1) and (2), with κ=1, also predicts a difference of only 0.26 sec.
[0029] Since this discrepancy between the theoretical prediction and the measured time for the conventional 200 m run does not stem from the assumed form of the resistive force, it must be associated with the thrust force Fcosθ. It is evident from Eq. (5) that the values of F, v and R n determine the angle θ. If, for example, the runner provides a maximum thrust force F at too great an angle to the direction of motion at one particular step, then he or she must correct for this during subsequent steps, in order to stay in lane. Furthermore, he or she must do this while controlling limbs, torso and head that are also experiencing centrifugal force. It would be very surprising if the runner could manage this perfectly by providing maximum thrust force F at exactly the correct angle θ at each step. The parameter κ(0<κ<1) is a measure of how well the runner does this. In fact, it is a measure of relative efficiency, i.e., of how well the runner manages running the curve compared to running the straight (providing maximum thrust force at angle θ=0). Equation (1) represents the limit of Eq. (2) as R n →∞, provided κ→1. While one would expect the efficiency parameter κ to depend on the curvature, it is convenient to assume that it is effectively constant over the limited range of radii R 1 to R 8 .
Simulations
[0030] Equations (1) and (2) were used to simulate a conventional 200 m run in Lane 3 and iterated to find the value of κ that would give the measured world record time. This led to the realistic value κ=0.963, which represents a 3.7% drop in efficiency. A 4×100 m relay runner is often assigned to run a particular leg because he or she “runs the curve well.” This runner would be characterized by an unusually high value of κ.
[0031] Having identified three parameter values that reproduce the three measured world records times, namely
V =10.753 m sec −1 ; β=0.0805 m −1 κ=0.963 (11)
conventional 200 m runs in each of the eight lanes can be simulated. Simulation of the 400 m runs requires a modification, because the 400 m is not a sprint, i.e., a runner cannot sustain maximum thrust force F for 400 m. A more realistic assumption is that he or she can sustain a constant reduced thrust force γF and comparison of predicted times with current world record times suggest a reduction of approximately 20% (γ=0.8). This corresponds to a √{square root over (γ)} reduction in speed. A useful scaling property of Eqs. (1) and (2) implies that the time for a 400 m run in any lane may be found by first treating the race as a sprint and then dividing the calculated race time by √{square root over (γ)}.
[0032] Substituting these parameter values in Eqs. (1) and (2) leads to
ⅆ 2 x ⅆ t 2 = 0.0805 { 115.63 - ( ⅆ x ⅆ t ) 2 }
and ( 12 ) ⅆ 2 x ⅆ t 2 = 8.9636 { 1 - ( ⅆ x ⅆ t ) 4 ( 9.3080 R n ) 2 } 1 / 2 - 0.0805 ( ⅆ x ⅆ t ) 2 ( 13 )
[0033] Even though Eq. (12) can be integrated in closed form (see Eq. (8)), it is convenient to integrate both equations numerically, using Mathematica NDSolve using the following procedure:
1. Substitute the appropriate value of R n from Eq. (7) in Eq. (13). 2. Solve Eq. (13), with initial conditions
x ( 0 ) = 0 ; ⅆ x ⅆ t ( 0 ) = 0 ( 14 )
to find the time at which x=100 m and the speed at that time. (This will be the terminal speed V n .)
3. Solve Eq. (12), with initial conditions
x ( 0 ) = 0 ; ⅆ x ⅆ t ( 0 ) = V n ( 15 )
to find the time at which x=100 m. The speed at that time will be V.
4. The sum of these two times is the 200 m time. 5. Solve Eq. (13), with initial conditions
x ( 0 ) = 0 ; ⅆ x ⅆ t ( 0 ) = V ( 16 )
to find the time at which x=100 m.
6. The time for the fourth 100 m will be the same as that for the second. 7. The sum of these four times is the 400 m sprint time. 8. Divide by √{square root over (γ)} (multiply by 1.12) to get the 400 m time.
[0042] The results of these calculations (in seconds) are listed as T conv (for the 200 m) and T conv (for the 400 m) in Table 1.
TABLE 1 Lane T conv T* conv T conv T* prop 1 19.87 43.66 19.64 43.39 2 19.85 43.60 19.63 43.38 3 19.83 43.56 19.63 43.37 4 19.82 43.53 19.63 43.37 5 19.80 43.49 19.63 43.36 6 19.79 43.46 19.63 43.36 7 19.78 43.43 19.63 43.35 8 19.76 43.40 19.62 43.35 Δ 0.11 0.26 0.01 0.04
[0043] An additional row, labeled Δ, is included listing the differences between times for Lane 1 and Lane 8 , because simply subtracting the listed times may lead to round-off errors.
[0044] These calculations may be repeated without the efficiency factor, i.e., setting κ=1 in Eq. (2). This led to the decrease of 0.15 sec below the measured Lane 3 record time, mentioned above, and to the same decrease below the calculated times T conv for all lanes. So, omission of the efficiency factor did not change the predicted discrepancies between times for the various lanes. If the 400 m is modeled as a sprint (setting γ=1), then the race times are reduced significantly. However, the change in the predicted discrepancy between lane 1 and lane 8 is reduced from 0.26 sec to 0.23 sec, for the conventional 400 m, and is unchanged for the proposed 400 m.
The Theories of Keller and Alexandrov and Lucht
[0045] The counterparts of Eqs. (1) and (2) in the theories of Keller and Alexandrov and Lucht are
ⅆ v ⅆ t = a ( V - v ) ; V = F a
and ( A1 ) ⅆ v ⅆ t = aV { 1 - v 4 R n 2 } 1 / 2 - av ( A2 )
Integration of the first Eq. (A1), with initial condition v(0)=0, gives
v=V (1 −e −αt ) (A3)
[0046] A second integration, with x(0)=0 and assuming that the time T is such that the exponential term is negligible, gives the counterpart of Eq. (9) as
X ≈ V ( T - 1 α ) ( A4 )
Setting dv/dt=0 in Eq. (A2) gives Vn as the root of a quadratic equation
v n 2 = 1 2 α 2 R n 2 [ { 1 + ( 2 V α R n ) 2 } 1 / 2 - 1 ] ( A5 )
[0047] We can now compare this theory with that presented in Section 2, without the efficiency factor (κ=1). If the predictions of the two theories for straight runs are to agree, then the two terminal speeds (V) must be the same. If the asymptotic distance is also to be the same for both theories, then comparing Eqs. (9) and (A4) gives
α = β V ln 2 ( A6 )
[0048] The speed versus time curves from Eqs. (3) and (A3), with parameter values from Eqs. (11) and (A6) are shown in FIG. 2 and they agree very well. While the formulae in Eqs. (4) and (A5) are different, they also show very good agreement. For example, the terminal speeds for Lane 1 are 10.4066 m sec −1 , from Eq. (4), and 10.4026 m sec −1 , from Eq. (A5).
[0049] Thus the predictions of the two theories (linear and quadratic resistive force laws), without the efficiency factor and specialized to constant thrust force, are virtually identical. It can be shown that the same is true for other realistic forms of the resistive force law.
New Track Configuration
[0050] Differences of 0.11 sec or 0.26 sec between the times of equally good athletes running in lanes with different curvatures are quite bothersome, since 200 m and 400 m races are often decided by much smaller margins. Thus, a new track configuration for these races is designed to reduce or eradicate these differences. The underlying principle is that competitors in different lanes, instead of running equal arc lengths on the curves, as they do in the present system, will run equal arc angles. As will be seem below, the modification consists of a reconfiguration of the track shape as well as a new formula for determining staggered starting positions.
[0051] The proposed track design according to one embodiment of the invention is shown in FIGS. 1C-1E . The track configuration features straight segments 110 and 120 extending from points 102 and 105 , respectively. The straight segments 110 and 120 have a length of half of the curved semi-circular section to which they attach, or 50 m for a standard 400 m track in one embodiment. These straight segments extend away from track 11 in opposite directions, both perpendicular to the existing straightaways. As is shown in FIG. 1D , straight segment 110 includes lane markers that merge with the existing lane markers of track 11 at point 102 (segment 120 , not shown, includes identical markings). If adopted, the new segments 110 and 120 would not affect other track or field events. These segments would be easily accommodated in construction of a new stadium and it would be a fairly straightforward renovation of an existing stadium, provided space is available. Segment 110 protrudes a distance 8.41 m beyond the outer edge of the track extending from point 106 to 101 . Segments 110 and 120 may be designed to terminate in a rectangular shape such as is illustrated in FIG. 1C or may be angled to accommodate the staggered starting positions such that the straight section extends further at lane 1 than at the outer lane. Such an angled configuration may prove advantageous in a tight space.
[0052] Under the proposed scheme, each athlete runs the same arc angle—a quadrant of a circle in the 200 m and a quadrant and a semi-circle in the 400 m. The offsetting effect is that runners in the less curved outer lanes, for whom the centrifugal effect is less severe, are required to run longer arc lengths. The model calculations predict that the proposed modification achieves almost complete parity for the 200 m and reduces the “Lane 8 advantage” from 0.26 sec to 0.04 sec. for the 400 m. Adoption of the proposed redesign would result in lower records, especially in 200 m events. Calculated times for Lane 4 , for example, in Table 1 predict a 0.19 sec reduction in the 200 m and a 0.16 sec reduction in the 400 m.
[0053] It is rather curious, as pointed out by Alexandrov and Lucht, that Lane 8 is not the preferred lane assignment, even though the mechanics indicates that it should be. Runners seem to feel that not being able to see one's competitors during the early stages of a race, due to the staggered start, is disadvantageous. This is psychological (motivational) rather than strategic in events where the only strategy is to run flat out. Interestingly, in indoor track, where the curves are tighter and the centrifugal effect is correspondingly more severe, the outer lanes 5 and 6 are the preferred lanes.
[0000] 200 m Race Track Configuration
[0054] Turning to FIG. 1C , for a 200 m race, the runner in Lane 1 , instead of running a 100 m semi-circular arc from point 101 to 102 to 103 followed by a straight 100 m from point 103 to 104 , will run a straight 50 m on segment 110 from point 107 to 102 followed by a 50 m circular quadrant from point 102 to 103 and a straight 100 m from point 103 to 104 . Each of the other runners will also run a straight segment of length 100−πR n /2 m followed by a circular quadrant of length πR n /2 and a straight 100 m. This means that the nth stagger distance is πR n /2−50 m. Such a configuration allows each competitor to run equal arc angles since the staggered starting position are on a straight portion while still utilizing the common finish line at point 104 .
[0055] It follows from Eqs. (6) and (7) that the various segments lengths (in meters) are as listed in Table 2.
TABLE 2 Lane Straight Curved Straight 1 50 50 100 2 48.08 51.92 100 3 46.17 53.83 100 4 44.25 55.75 100 5 42.33 57.67 100 6 40.42 59.58 100 7 38.50 61.50 100 8 36.58 63.42 100
[0056] Times for this new 200 m run are calculated from Eqs. (12) and (13) as before and the results (T prop ) are listed in Table 1. Two aspects are especially noteworthy. The first is that the new design almost completely eradicates the discrepancies between the times for the various lanes. The second is that the times for all eight lanes are lower than those for the present 200 m run (T conv ). This is obviously because all eight runners will run less than 100 m on the curve.
[0057] For a runner in Lane 1 , the conventional 200 m requires running a 100 m semi-circle and the proposed 200 m requires running a 50 m circular quadrant. So, in a certain sense, the proposed run is halfway between the conventional run and a straight run. This is reflected in the calculated times for the conventional run (19.87 sec) and the proposed run (19.64 sec) and the measured time for the straight run (19.40 sec).
[0000] 400 m Race Track Configuation
[0058] Turning to a 400 m race, a runner in Lane 1, instead of running a 100 m semi-circle from point 104 to 105 to 106 , a straight 100 m from point 106 to 101 , another 100 m semi-circle point 101 to 102 to 103 and another straight 100 m from point 103 to 104 , the runner in Lane 1 will run a straight 50 m on segment 120 from point 108 to 105 , then a 50 m quadrant from point 105 to 106 , a straight 100 m from point 106 to 101 , a 100 m semi-circle from point 101 to 102 to 103 and another straight 100 m from point 103 to 104 . Additionally, if having the 200 m and 400 m events finish on opposite sides of the track is acceptable (from the spectators' standpoint), then only one additional feature is necessary (i.e., only segment 110 and not segment 120 need be added). For example, the Lane 1 runner in the 400 m could run the course from point 107 to 102 to 103 to 104 to 105 to 106 to 101 . In the old configuration, each of the other runners begins with a circular arc that is greater than a quadrant and less than a semi-circle, then runs a straight 100 m, then a semi-circular arc and another straight 100 m. In the configuration of the present embodiment, each of the other runners will begin with a straight segment, then run a quadrant, straight 100 m, a semi-circle and another straight 100 m. The segment lengths, in order, are 200−3;πR n /2, πR n /2, 100, πR n , 100 m. The nth stagger distance is 3πR n /2−150 m. Such a configuration allows each competitor to run equal arc angles since the staggered starting positions are on a straight portion while still utilizing the common finish line at point 104 .
[0059] The various segments lengths (in meters) are listed in Table 3.
TABLE 3 Lane Straight Curved Straight Curve Straight 1 50 50 100 100 100 2 44.25 51.92 100 103.83 100 3 38.50 53.83 100 107.67 100 4 32.75 55.75 100 111.50 100 5 27.00 57.67 100 115.33 100 6 21.25 59.58 100 119.17 100 7 15.50 61.50 100 123.00 100 8 9.75 63.42 100 126.83 100
[0060] With Table 3 and Eqs. (6) and (7), the equations of motion (12) and (13) may be integrated, as before, to get times for the various lanes for the proposed 400 m run. These times (T prop) are given in Table 1. Notice that the discrepancies between times for the various lanes are greatly reduced (Δ=0.04 sec). The times for all lanes are reduced because all eight runners runs less than 200 m on the curve. For a runner in Lane 8 , the conventional and proposed 400 m runs are almost the same ( FIG. 1 ) and this is reflected in the calculated times, which differ by 0.04 sec.
[0061] FIG. 1E illustrates a configuration of track 11 according to a preferred embodiment. Straight section 110 is marked with the staggered starting positions listed in Table 2 for a 200 m race finishing at point 104 and straight section 120 is marked with the staggered s listed in Table 3 for a 400 m race also finishing at point 104 . It should also be noted that the new track configuration illustrated in FIG. 1E requires minimal modification of other track markings. The location of hurdles for the 400 m hurdles does not change except for the first hurdle in lane 1 and the locations of the exchange spots for the 4×100 m relay remain the same. Additionally, for both the 200 m and the 400 m race, the splits between the staggered starting positions are reduced as compared to the traditional 200 m and 400 m races respectively.
[0062] In another embodiment, straight sections 110 and 120 are not utilized; rather, runners run equal arc angles by starting at staggered starting positions along a straightaway section. Such a configuration would result in slower times than the traditional configuration as runners would run an entire semicircular curved portion in a 200 m race. Further, such a configuration would require new hurdle and relay exchange locations and would not allow the 200 m and 400 m races to share a common finish line.
A Simpler Analysis
[0063] The running times listed in Table 1 were calculated by solving the nonlinear ordinary differential equations (12) and (13) numerically. An alternative simpler analysis approximates these results very well.
[0064] To begin, recall Eq. (9):
X ≈ VT - 1 β ln 2 ( 9 )
Since the first term on the right represents the distance run in time T at constant speed V, the second term is the correction for the initial acceleration phase as can be seen in graph 20 in FIG. 2 . The treatment of a race may be simplified by adopting the approximation Eq. (9) for the first segment and by assuming the every subsequent segment is run at constant speed V, on the straight, or V n , on the curve. Thus, the continuous accelerations and decelerations as the runner's speed changes from V n to V and back may be ignored, assuming instead that these changes occur instantaneously. Then the time T n for a race over a distance L run in Lane n is given by
T n = L - L n V + L n V n + ln 2 β V ( 17 )
if the race begins with a straight segment, and by
T n = L - L n V + L n V n + ln 2 β V n ( 18 )
if it begins on a curve.
[0065] Introducing the dimensionless parameters λ n and Ψ n defined as
λ n = L n L ; Ψ n = L n V n ( 19 )
leads to
T n = L V { 1 + λ n ( Ψ n - 1 ) } + ln 2 β V ( 20 )
or its counterpart from Eq. (18). Notice that the curved length fraction λ n has the value ½ for all lanes in the conventional 200 m and 400 m, so that Eq. (20) reduces to
T n = L 2 V ( Ψ n + 1 ) + ln 2 β V ( 21 )
[0066] Equation (20) provides some insight as to why the proposed redesign eradicates the centrifugal effect. The key term is λ n (Ψ n −1). Since Ψ n is inversely proportional to V n , it decreases as the lane number n increases from 1 to 8. For conventional 200 m and 400 m races, the curved length fraction λ n is constant. Thus, there is no offsetting effect and so the time T n also decreases as n goes from 1 to 8. For the proposed new 200 m and 400 m runs, however, the curved length fraction λ n increases as n goes from 1 to 8. Fortuitously, this increase almost exactly offsets the decrease in Ψ n −1, so that values of λ n (Ψ n −1), listed in Table 4, are almost constant.
TABLE 4 Lane 1 Lane 2 Lane 3 Lane 4 Lane 5 Lane 6 Lane 7 Lane 8 0.0130 0.0129 0.0128 0.0127 0.0126 0.0125 0.0125 0.0125
These differences in the fourth decimal place have virtually no effect, even when multiplied by LN.
[0067] Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps. | The present invention is directed to a system and method for conducting a more fair race around an oval track by having runners in each lane run equal arc angles. Such a configuration eliminates the disproportionate effect of centrifugal force on competitors running in different lanes. Embodiments of the invention provide for the addition of a straight section to a standard oval track extending from a curved section perpendicular to the existing straightaway section. Runners in each lane start at staggered locations on the straight section. The staggered starting locations are chosen such that each runner travels an equal distance from the starting location to a common finish line. A single straight section may be employed to conduct races covering the entire length and half the length of the oval track or two straight sections may be employed to allow finishes for both races at a common finish line. | 0 |
FIELD OF THE INVENTION
The present invention relates to a sensor, in particular for the spatially resolved detection, and to a method for its production.
BACKGROUND INFORMATION
DE 101 14 036 describes a method for producing micropatterned sensors, in which openings are introduced into a semiconductor substrate, which transform themselves into cavities underneath a sealed diaphragm cover in the depth of the substrate in a subsequent thermal treatment. This makes it possible to produce a capacitive pressure sensor, the cavity in the substrate being developed between two doping zones, which form a plate-type capacitor having a capacitance as a function of the spacing of the doping zones. The doping zones are connected to a corresponding evaluation circuit by deep contacting.
DE 10 2004 043 357 describes a method for producing a cavity in a semiconductor substrate, in which a lattice-type structure on the surface of the substrate is first produced from substrate material not rendered porous, between which or underneath which a porous region is subsequently formed into the depth of the semiconductor substrate. The porosified region is relocated into a cavity by a subsequent thermal treatment, the lattice-like structure being developed into a diaphragm or into part of a diaphragm above the cavity, if appropriate.
However, such production methods often do not allow the development of more complex sensors having high resolution and low noise.
SUMMARY
In contrast, the micropatterned sensor according to example embodiments of the present invention and the method for its production have a number of advantages. At least one, preferably several sensor elements that are laterally set apart are formed within a substrate, each being suspended underneath a diaphragm made of dielectric material. The sensor elements may be diodes, in particular, but basically also transistors, for example. Important is that the individual sensor elements have a temperature-dependent electric characteristic whose values are able to be read out via lead wires.
The individual sensor elements are suspended in one or several cavities formed underneath the diaphragm. In this context, a separate cavity may be provided for each sensor element, or several or all of the sensor elements may be disposed within one shared cavity.
The individual sensor elements are contacted via lead wires, which run within, on top of or underneath the diaphragm. The diaphragm may be patterned such that it forms individual suspension springs, which link each sensor element to the surrounding mainland or to surrounding webs of an epitaxy layer formed on top of or above the substrate.
According to an example embodiment, reinforcements, specifically LOCOS (local oxidation of silicon) reinforcements produced by local oxidation, are formed in the dielectric layer constituting the diaphragm, which increase the mechanical stability considerably. The reinforcements may be formed especially at the lateral edge of the diaphragm, so that they surround the particular sensor element; furthermore, they may extend at the lateral edge of the mainland or the remaining webs supporting the sensor elements and thereby accommodate the suspension springs with high stability. The ultimate tensile strength of the suspension springs at the sensor elements and the mainland or the remaining webs is able to be increased in this manner.
Because of the diaphragm, in particular because of the suspension springs in the diaphragm, excellent thermal decoupling of the sensor elements with respect to each other and the mainland is achieved. Developing the sensor elements in an epitaxial and thus monocrystalline layer makes it possible to keep the signal noise very low. This is advantageous in particular when forming diodes or transistors.
Thus, a component array having high resolution or a high number of sensor elements and low noise is formed, which may have a mechanically very sturdy design. The individual lead wires to the sensor elements can be connected to shared lead wires, so that the individual components may be read out via successive addressing. Due to the high integration, the power requirement is low.
In particular, this makes it possible to produce a diode array for the spatially resolved temperature measurement and/or for the spectroscopic measurement of a gas concentration. Another field of application is a fingerprint sensor.
According to an example embodiment, the sensor not only includes the detector region having the sensor elements but, laterally adjacent and advantageously isolated therefrom, a circuit region including additional components to evaluate the signals output by the sensor elements. At least a few of the process steps of forming the sensor elements of the detector region may also be utilized to produce the circuit region, so that a rapid and cost-effective production is possible. Thus, a MEMS (micro electro mechanical system) component having a combined sensor system and electronic evaluation circuit is able to be formed on one chip.
The production may be implemented entirely by surface-micromechanical process steps, so that only one surface needs to be processed. The production may be implemented at the level of the wafer with subsequent sectioning.
To begin with, a first region of the doped substrate (or a doped layer formed on the substrate) is rendered porous for the production, a lattice-like structure and a second region surrounding the first region first being protected from the subsequent etching process by suitable doping. Thus, the first region underneath the lattice-type structure may subsequently be rendered selectively porous in electrolytic manner; if appropriate, complete removal of the material in this region is also possible already. An epitaxial layer may then be grown on the lattice-like structure and the surrounding mainland, annealing of the porous region being implemented during the growing process (or possibly also in an additional step) while forming a cavity.
Thus, an epitaxial monocrystalline layer in which the sensor elements are subsequently developed by additional process steps, e.g., by doping corresponding diode regions, may be formed above the cavity. Since the sensor elements are developed in the monolithic epitaxial layer, they exhibit low signal noise. The cavity already thermally insulates them from the substrate.
Further insulation is achieved by developing a diaphragm underneath which the sensor elements are suspended. To this end, one (or several) dielectric layer(s) is/are applied on the epitaxy layer and then patterned. In particular, the dielectric layer may be formed by oxidation or deposition of an oxide layer, formation of etching accesses through the dielectric layer and the epitaxy layer, as well as subsequent sacrificial layer etching of the epitaxy layer. The at least one dielectric layer thus forms a diaphragm, which is self-supporting above the cavity and accommodates the particular sensor element in thermally and mechanically decoupled manner. Further thermal decoupling may be achieved by patterning suspension springs in the diaphragm, thereby making it possible to route the electrical lead wires to the sensor elements via the suspension springs.
Example embodiments of the present invention are explained in greater in the following text with the aid of the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 a through 1 f illustrate the process steps of the production of a micromechanical sensor according to an example embodiment, exemplarily for one diode pixel of the sensor;
FIG. 1 a illustrates a preliminary circuit process and a process step for developing a lattice structure in the detector region;
FIG. 1 b illustrates the process step of an n-layer epitaxy;
FIG. 1 c illustrates the process steps of the implantation or diffusion in the circuit region, production of dielectric layers, and patterning of the contact holes in the dielectric layers;
FIG. 1 d illustrates the back end circuit process with the development of a full-area metal cover of the diaphragm, and of passivation layers in the circuit region;
FIG. 1 e illustrates the process steps of removing the layer stack above the first metallization layer, patterning the metallization in the region of the diode pixels, and opening sacrificial-layer etching accesses, or suspension springs in the remaining dielectric layer;
FIG. 1 f illustrates the isotropic sacrifical layer etching to expose the diode pixel;
FIG. 2 illustrates an example embodiment as an alternative to FIG. 1 f with retroactive formation of a cavity from the rear side;
FIG. 3 illustrates a plan view of a finished diode pixel according to FIG. 1 f or FIG. 2 ;
FIG. 4 illustrates a cross section through a sensor having a plurality of diode pixels and continuous, shared free space;
FIG. 5 illustrates a plan view of the sensor of FIG. 4 having a plurality of diode pixels.
DETAILED DESCRIPTION
In the production process, a detector region 2 and, laterally spaced apart or abutting, a circuit region 3 are formed on a p-semiconductor substrate 1 , e.g., p-doped (100) silicon; the development of the two regions 2 , 3 is able to be fully or partially combined in the subsequent process steps.
According to FIGS. 1 a through 1 f , both the circuit region 3 and detector region 2 are implemented in surface-micromechanical manner from the top surface of p-substrate 1 . To this end, preliminary circuit processes to form circuit region 3 may be implemented to begin with. Process steps for forming circuit region 3 may also be added between the subsequent process steps 1 a through 1 f . In an advantageous manner, one or several of the following process steps for developing detector region 3 is/are simultaneously utilized to produce circuit region 3 .
Using p + doping, for example, a lower iso-layer 6 , which has the shape of a trough in cross section, may be formed in p-substrate 1 between detector region 2 and circuit region 3 , lower iso-layer 6 being supplemented toward the top in a later process step and utilized to insulate detector region 2 from circuit region 3 .
For each sensor element to be produced, a first region 12 is rendered porous in detector region 2 , a lattice-like structure 14 having lattice webs 16 remaining on the surface of first region 12 . In the lateral region, first region 12 is advantageously delimited by an annular second region 18 . First region 12 and second region 18 are doped to different extents, especially by a different type of charge carrier. First region 12 is p-doped, for example, that is to say, it may be formed directly out of p-substrate 1 in particular, and second region 18 is n + -(or also n-)doped. In principle, first region 12 may also be completely removed already so that a free space remains as “100% porosity” underneath lattice-type structure 14 .
The production of this array of a porosified first region 12 , a surrounding second region 18 , and a spared lattice-type structure 14 is described in DE 10 2004 036 035 as well as DE 100 32 579, for example, to which reference is made here for individual details. Second region 18 is produced at the lateral edge of first region 12 , for instance by redoping, such as with the aid of implantation and/or diffusion methods. Furthermore, lattice-type structure 14 having lattice webs 16 is formed by n-doping, and lower iso-layer 6 is formed by p + -doping. These designs of second region 18 , lattice-like structure 14 , and lower iso-layer 6 is realizable with the aid of, for example, resist masks prior to the further process steps, i.e., also prior to the etching.
Subsequently, an etching mask 20 of SiO2 and/or Si3N4, for example, is deposited on detector region 2 and circuit region 3 and patterned such that first region 12 having lattice-like structure 14 is spared. Only then will first region 12 be rendered porous by electrochemical etching in an electrolyte containing hydrofluoric acid. A spreading agent such as isopropanol, ethanol, or a tenside may be added in order to reduce the surface tension. Depending on the substrate doping and the desired micropattern, the concentration of hydrofluoric acid may range from 10 to 50%. The porosity of first region 12 is adjustable by the selected current density.
Lattice webs 16 and annular, n + -doped second region 18 are not attacked by the electrochemical etching process since holes (defect electrons) are required for the dissolution process of silicon, of which a sufficient number is available in the p-silicon but not in the n-Si. Second region 18 therefore delimits first region 12 in the lateral direction, and the depth of first region 12 is defined by the etching duration and current intensity.
According to FIG. 1 b , an n-epi layer 24 is subsequently deposited or grown on p-substrate 1 epitaxially, such layer extending across detector region 2 and circuit region 3 . During this epitaxial growth process, annealing of porous first region 12 also takes place, which leads to thermal relocation of the porous material and thus to the formation of a cavity 26 underneath n-epi layer 24 . In the process, a monocrystalline layer precipitates from the porous material and deposits on the walls of cavity 26 . Lattice webs 16 relocate to form, for example, a monocrystalline layer 28 between cavity 26 and n-epi layer 24 . This annealing step may be implemented at approximately 900 to 1200° C., for example. The formation of a cavity 26 out of a porous region is described in DE 10 2004 036 035, for instance.
According to example embodiments of the present invention, larger-area regions may optionally remain in lattice-type structure 14 , so that only a weak porosification takes place underneath them, i.e., merely by lateral etching. These more weakly porosified regions may form temporary support points 30 inside cavity 26 during annealing, which thus support layer 28 and n-epi layer 24 above cavity 26 .
According to FIG. 1 c , suitable structures are subsequently developed within and/or on top of n-epi layer 24 , which may be implemented both in detector region 2 and also in circuit region 3 . Different implantation- or diffusion-process steps for developing the circuits may be utilized in circuit region 3 in a manner known per se. An n + -region 32 and a p + -region 34 are formed in detector region 2 in n-epi layer 24 for each future pixel via implantation and/or diffusion. N-epi layer 24 together with p + -region 34 forms a diode in the process. Furthermore, one or a plurality of dielectric layer(s) 36 is/are developed, e.g., by oxidation to SiO2, locally thicker LOCOS reinforcement regions 38 being developed at least in detector region 2 by a LOCOS method. To this end, stronger oxidation accompanied by a corresponding increase in volume and thus thickening in the vertical direction are obtained in SiO2 layer 36 by suitable masking. LOCOS reinforcement regions 38 are formed at the edge of the future pixels in particular, i.e., above the edges of cavity 26 . Corresponding LOCOS reinforcement regions 38 may also be formed in circuit region 3 .
Furthermore, the one or the several dielectric layer(s) 36 is/are patterned in circuit region 3 and in detector region 2 . In so doing, access holes 40 , 42 for the subsequent contacting are patterned above n + -region 32 and p + -region 34 . Different components 44 , for example, are patterned in circuit region 3 . LOCOS reinforcements 38 may be formed here as well.
According to FIG. 1 d , metallizations and passivations, e.g., a metallization layer 48 including contact pad 50 , and one or a plurality of passivation layer(s) 54 are applied in a backend circuit process. Metallization layer 48 of Al, for example, contacts n + -region 32 and p + -region 34 in cut-out access holes 40 , 42 of dielectric layer 36 . Metallization layer 48 is utilized accordingly also in circuit region 3 for contacting the components 44 formed there, for supply lines and possibly also for components. Metallization layer 48 advantageously also forms connecting lines 56 between detector region 2 and circuit region 3 so that an integrated component is produced, which has a detector region 2 and a circuit region 3 .
One or a plurality of metallization layer(s) 50 made of, e.g., Al may be developed in the process. N + -region 32 is provided merely for contact with metallization layer 50 so that no Schottky contact occurs between the metal and the heavily doped region. Actual diode 35 is formed between n-epi layer 24 and p + -region 34 , which because of its heavy doping likewise does not cause any Schottky contact with metallization layer 50 . As can be gathered from FIG. 1 d , n-epi layer 24 is able to be insulated from circuit region 3 in the lateral direction by an upper iso-layer 31 and, above this, by a LOCOS reinforcement 38 .
The one or the plurality of metallization layer(s) 48 is/are also used to prevent the deposition of the one or the plurality of passivation layer(s) 54 above diode 35 .
Passivation layer 54 is subsequently removed above diode 35 , metallization layer 48 serving as etching stop. Metallization layer 48 is then suitably patterned above diode 35 , so that only n+-region 32 and p + -region 34 are contacted by connecting lines 60 , 62 , as can be gathered from the plan view of FIG. 3 (the additional patterning of FIG. 3 takes place only subsequently).
Furthermore, according to FIG. 1 e , sacrificial-layer etching accesses 66 are opened in n-epi layer 24 , preferably by reactive ion etching through n-epi layer 24 . A BRIE method may be used for this purpose or, since the n-epi layer has a thickness of only a few μm, for example, a conventional reactive ion etching method, such as a Bosch etching method, as well. In the process, sacrificial-layer etching accesses 66 are produced in n-epi layer 24 , which forms the preliminary diaphragm. Sacrificial-layer etching accesses 66 are already visible in the plan view of FIG. 3 , although connecting lines 60 , 62 are not yet undercut by etching. According to FIG. 1 f , this takes place in a subsequent isotropic sacrificial-layer etching step using ClF3, XeF2, for example, or some other etching gas that selectively etches silicon, until the monocrystalline region of diode pixel 52 has been exposed by etching. A portion of the one or the plurality of dielectric layer(s) 36 is undercut by etching with the aid of the sacrificial-layer etching and exposed as diaphragm 36 . 1 in this way. Patterned diaphragm 36 . 1 forms elastic suspension springs 70 on which connecting lines 60 , 62 to n + -doped region 32 and to p + -doped region 34 extend as well.
If temporary supports 30 are formed according to FIG. 1 b , then they will be removed as well during the underetching according to FIG. 1 f.
Diode pixel 52 is therefore supported by the, e.g., four suspension springs 70 , which hang freely now, LOCOS reinforcements 38 being formed in suspension springs 70 or at the transition of suspension springs 70 to the mainland. As a result, individual diode pixels 52 are thermally well insulated from one another and from the remaining mainland via suspension springs 70 made of the insulating SiO2.
Diode pixel 52 shown in FIG. 3 may be used for direct temperature sensing, in particular. In addition, an absorption material for absorbing IR radiation may be applied on diode pixel 52 .
The precise design of LOCOS reinforcement 38 may be selected according to the particular mechanical requirements; according to the plan view of FIG. 3 , it is possible, in particular, to provide an annular reinforcement at the inner end of suspension springs 70 , i.e., at the outer end of diode pixel 52 , and at the outer edge of suspension springs 70 , i.e., in the connection to the mainland. In this manner, two concentric, annular or rectangular LOCOS reinforcements 38 and 38 are formed.
FIG. 1 f and, in a plan view, FIG. 3 therefore show finished sensor 72 , which as a rule includes a plurality of diode pixels 52 and circuit region 3 having a suitable evaluation circuit.
In the example embodiment of FIG. 2 as an alternative to that in FIG. 1 f , a cavity 74 is formed from rear side 76 of p-substrate 1 or the entire wafer in addition. To this end, a bulk etching process may be implemented from rear side 76 of p-substrate 1 . To protect the structures of diode pixel 52 , proceeding from FIG. 1 f , an oxide layer 78 may first be formed at the boundary surfaces of all structures as first process step, i.e., at p-substrate 1 , n-epi layer 24 , both in the mainland region and at diode pixel 52 , and furthermore at second region 18 having n + -doping. This oxidation of the silicon to SiO2 may therefore first be implemented from the direction of the front side, whereupon a deep-trenching etching process is then carried out from rear side 76 of p-substrate 1 , and cavity 74 is formed, which thus is situated underneath individual diode pixel 52 .
Cavity 74 may thereupon be sealed using a suitable material, e.g., a material having low thermal conductivity. With the exception of additional cavity 74 underneath diode pixel 52 , sensor 82 of FIG. 2 therefore corresponds to sensor 72 shown in FIG. 1 f.
FIG. 4 shows an additional example embodiment of a sensor 92 , which basically corresponds to sensor 72 of the first specific embodiment according to FIGS. 1 f , 3 ; however, instead of a plurality of separate cavities 26 being developed underneath the plurality of diode pixels 52 , only one continuous cavity 94 is formed, which therefore surrounds all of the diode pixels 52 or a number of diode pixels 52 . In contrast to the first example embodiment, the support of diaphragm 36 . 1 in p-substrate 1 is therefore omitted. However, webs 96 from n-epi layer 24 remain between individual diode pixels 52 and are not etched off, these webs 96 or the lattice-type structure formed thereby being utilized for heat dissipation. During operation, the plurality of diode pixels 52 initially heat up slightly, and the heat they generate is output in lateral direction to webs 96 via diaphragm 36 . 1 formed from dielectric layer 36 , the silicon material of webs 96 having high thermal conductivity. As a result, it is possible to dissipate the heat generated in individual diode pixels 52 to the outside in the lateral direction. In the specific embodiment of FIG. 4 , a single continuous cavity 94 is therefore produced, at whose underside individual diode pixels 52 , which were formed out of n-epi layer 24 , are suspended.
FIG. 5 shows a plan view of a diode array made up of four diode pixels 52 . Connecting lines 60 , 62 of each diode pixel 52 may be connected to shared connecting lines 98 , 100 ; as a result, (cathode) connecting lines 60 contacting the particular n + -region 32 , are connected to a shared cathode connecting line 100 - 1 , 100 - 2 , . . . , and (anode) connecting lines 62 contacting the particular p + -region 34 are connected to one or a plurality of shared anode connecting line(s) 98 - 1 , 98 - 2 , . . . . The individual diode pixels 52 are therefore able to be read out via corresponding addressing of shared connecting lines 98 - 1 , 98 - 2 , . . . , as well as 100 - 1 , 100 - 2 .
Given such an array, it is therefore possible to form a complex diode array 110 having relatively few connecting lines. When forming a larger cavity 94 according to FIG. 4 , shared connecting lines 98 - 1 , 98 - 2 , . . . , 100 - 1 , 100 - 2 , . . . , may be applied on diaphragm 36 . 1 above webs 96 ; contacting of connecting lines 98 - 1 , 98 - 2 , . . . , 100 - 1 , 100 - 2 , . . . at the points of intersection is prevented by a corresponding insulation layer. | A sensor, in particular for the spatially resolved detection, includes a substrate, at least one micropatterned sensor element having an electric characteristic whose value varies as a function of the temperature, and at least one diaphragm above a cavity, the sensor element being disposed on the underside of the at least one diaphragm, and the sensor element being contacted via connecting lines, which extend within, on top of or underneath the diaphragm. In particular, a plurality of sensor elements may be formed as diode pixels within a monocrystalline layer formed by epitaxy. Suspension springs, which accommodate the individual sensor elements in elastic and insulating fashion, may be formed within the diaphragm. | 1 |
CROSS REFERENCE TO RELATED APPLICATIONS
This is a continuation-in-part of U.S. Ser. No. 000,332, filed Jan. 2, 1979 and now U.S. Pat. No. 4,272,936.
BACKGROUND OF THE INVENTION
The present invention relates to a new and unique variation of, and improvement over, conventional inverted roof structures. As a result of the practice of this invention, an inverted roof structure can be constructed which possesses superior fire-retardant, protective, and insulative properties, while concurrently significantly reducing the overall weight of the composite roof structure. It is an important feature of this invention that such improved structure can be constructed independent of the pitch angle the roof structure forms with the horizontal.
The method and structure of inverted roof systems is well known and practiced by members of the building profession. For example, U.S. Pat. No. 3,411,256, held by the Dow Chemical Company, (hereinafter, "Dow"), discloses an inverted roof structure, and method thereof, which comprises a roof deck, water impermeable membrane, closed cell water impermeable thermal insulating member, and a water permeable protective layer. This structure reduces exposure of the water impermeable membrane to adverse environmental conditions, thereby protecting the membrane and extending the useful like of the roof structure.
While the structure taught by Dow is now used throughout the building industry, the structure possesses several signficant limitations which renders it generally unsuitable for use under many naturally existing conditions. For example, inasmuch as the protective layer is water permeable, moisture passing therethrough ultimately contacts the underlying water impermeable membrane and can cause cracking of said membrane due to cyclical freezing and thawing conditions. Further Dow recognizes that the thermal insulation member is subject to decomposition, particularly when exposed to sunlight; however it fails to disclose a method by which the insulating member may be permanently protected from such elements. Still further, a roof structure constructed in accordance with the Dow disclosure utilizing styrene for the thermal insulation member requires approximately 1200 pounds of gravel per 100 square feet of roof surface area in order to receive an Underwriter's Laboratories Class A rating for fire retardancy. Finally, Dow fails to disclose a method by which the protective layer can be applied regardless of pitch angle, and, by necessity, structures constructed in accordance with the method of the invention are limited to low pitch angles.
Therefore, it is an object of the present invention to provide a roof structure which substantially inhibits the absorption of water which may adversely affect the water impermeable membrane.
Yet another object is to provide a protective layer which effectively inhibits deterioration of the underlying thermal insulation layer due to foot trafic and adverse environmental conditions.
A still further object is to provide a roof structure which may be constructed without roof pitch angle limitations.
And yet another object is to provide a roof structure characterized by superior insulative and fire retardant qualities while simultaneously achieving an overall reduction in the weight of the structure.
SUMMARY OF THE INVENTION
The present invention relates to a roof structure characterized by a thermal insulation layer secured to the exposed surface of a water impermeable roofing membrane. Adhesive material is thereafter applied to the exposed insulative layer surface and inorganic particles attached thereto in sufficient quantity to ensure that each particle contacts all other contiguous particles. The combination of adhesive and particulate forms what is known as a toothing surface, said surface serving as a means by which a final overlayment of inorganic mortar based compound may be secured to the roof structure. The final overlayment forms a protective skin which serves to retard water absorption through the roof structure, protect the substrate from injury due to foot traffic, ultra-violet light and adverse weather conditions, and increase the insulative "R" factor of the composite structure. It is a unique feature of the present invention that the incorporation of the toothing surface therein permits the application of the final overlayment at any roof pitch angle from horizontal.
In an alternate form of this invention suitable for use in conditions where enhanced insulation properties are a concern secondary to construction of a light-weight roof of superior water impermeability integrity, a bituminous material-containing first water impermeable layer is substituted and used in lieu of said mortar based layer. Disposed upon said first layer is a second water impermeable layer formed of elastomeric material having radiant energy reflective material in admixture therewith.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the preferred embodiment of this invention.
FIG. 2 is a perspective view of an alternate embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
For a more complete understanding of my invention reference is now made to the several figures wherein like reference numerals refer to like parts throughout the several views, and wherein FIG. 1 illustrates an inverted roof system 10 constructed in accordance with the preferred practice of the present invention. The inverted roof system 10 comprises a roof deck 11 secured upon a multiplicity of rafters or other suitable roof support structure (not shown), said roof deck 11 having an exposed outer surface 12. A water impermeable membrane, comprising a plurality of alternating layers of adhesive 13, roofing felt 14, and a final overlayment of adhesive-sealant coat 13A is thereafter secured to the roof deck 11 such that the exposed outer surface 12 of roof deck 11 is completely covered by the water impermeable membrane. Secured upon adhesive-sealant coat 13A, the outermost layer of the membrane, is a thermal insulation layer 15 having an upper surface 16. A toothing surface is formed upon the thermal insulation layer 15 by coating the upper surface 16 of layer 15 with an adhesive 17, and thereafter partially imbedding a singular layer of inorganic particles 18 into adhesive 17. The particles 18 are applied in sufficient quantity so as to ensure that the entire exposed surface of adhesive 17 is uniformly covered with the particles 18, each particle in continuous contact with contiguous particles. Finally, a mortar based insulative-protective layer 19 is applied onto the toothing surface, thereby completing the composite structure. If aesthetically desired, additional particles 18 may be partially imbedded into layer 19 prior to its solidification.
The roof support structure, the roof deck, water impermeable membrane, and thermal insulation layer may be constructed from a wide variety of materials well known to practitioners in the building industry. For example, the water impermeable membrane may be fashioned by overlapping alternating layers of asphaltic base adhesive and roofing felt in sufficient quantity to ensure water impermeable integrity, two or three layers of each usually considered as being satisfactory.
Selection of the proper sealant-adhesive coat to be overlayed upon the water impermeable membrane depends upon the practitioner's choice of material used to form the thermal insulation layer. Beneficially, such insulation layer would be comprised of closed cell plastic foam material such as polyurethane foams, styrene polymer foams, and others well known to the art.
Inasmuch as polyurethane foams and the like are characterized by a high degree of resistance to degradation and distortion when contacted with high temperature adhesive materials such as hot asphalt, either hot process or cold process adhesives may be utilized to seal the membrane and secure the thermal insulation layer thereon.
Styrene, however, is particularly susceptible to distortion and degradation when contacted with high temperature adhesive materials; therefore, the use of a cold process, water based acrylic resin or asphaltic emulsion for the sealant-adhesive coat is desirable in order to secure the styrene material upon the underlying substrate. Adhesives such as those manufactured by Thermo Materials, Incorporated of San Diego, Calif. under the names Thermo Concentrate #101A (thermo plastic acrylic polymer) and Thermo Series 200 E (asphaltic emulsion) have proven suitable for use in bonding the styrene to the membrane.
The aforementioned limitations similarly apply to the selection of the adhesive incorporated into the toothing surface. If styrene, or other similar thermo plastic synthetic resinous material is used to form the thermal insulation layer, the adhesive must be amenable to cold process application. Alternatively, hot asphalt may be utilized as an adhesive if interposed between the styrene and the adhesive is a protective layer of saturated asphaltic felts or the like which serve to inhibit styrene degradation.
While the adhesive utilized in the toothing surface is in a plastified state, +1/4 inch, -3/8 inch gravel, applied at the rate of approximately 150 pounds gravel per 100 square feet of adhesive surface area, is partially imbedded therein in sufficient quantity to ensure contiguous particle contact over the entire adhesive surface. Where the possibility of water ponding and continuous cyclical freeze/thaw conditions are likely to occur, gravel size must be increased to +1/4 inch, -5/8 inch.
When the roof structure has been thus far completed, the final construction step consists of the preparation and application of the insulative-protective layer. Basically, the layer is comprised of an inorganic mortar based compound made up of the following ingredients in substantially the proportions stated:
______________________________________White cement 51%Magnesium silica or calcium carbonate flour 38.5%Perlite fines; +200, -300 mesh 1.5%Clay; +200, -300 mesh 3.0%Lime; +200, -300 mesh 5.5%Thickener 0.2%______________________________________
The above mixture of dry powder is thereafter added in a continuous stream at the rate of 50 pounds powder to six gallons of water and agitated to ensure homogeneity. Finally, an additional one-half gallon of vinyl acrylic polymer or acrylic emulsion vehicle is added and uniformly dispersed throughout the mixture prior to ceasing agitation. The latter ingredient serves the purpose of increasing the compressive strength of the protective-insulative layer, and retards water absorption through the layer.
The ingredients disclosed in the above example will yield a white color composition. It should be understood, however, that color variation may be obtained by the addition of pigments or the like. Still further, the above example contemplates application of the mixture under moderate temperature conditions. If application is to be made at temperatures below freezing, five pounds of barium chloride per 50 pounds of dry powder may be added to accelerate prolonged setting associated with low temperature conditions.
The composition thus formed is thereafter uniformly applied with a pressure hose upon the entire toothing surface at a minimum rate of 50 pounds per 100 square feet of surface area. During application, the composition remaining to be used must undergo continuous agitation and any of the mixture not utilized within three hours of mixing must be discarded.
It is thus seen that upon solidification of the insulative-protective layer, a structure is formed possessing superior insulative, protective, and fire-retardant qualities over present state of the art structures. Further, by incorporating a toothing surface into the composite structure, a surface is formed whereby the insulative-protective layer may be secured to the roof structure without restriction due to the roof pitch angle.
Of course, climatic conditions vary widely depending upon geographical location. In certain of those locations the need for a light-weight roof structure of superior water impermeable integrity may be of paramount importance as opposed to a roof structure including both enhanced water impermeability and insulative properties, such as a roof constructed in accordance with the practice of the preferred embodiment of this invention. Accordingly, FIG. 2 illustrates an alternate form of this invention which distinguishes from the preferred embodiment shown in FIG. 1 by the substitution for the mortar based layer of a different overlayment structure disposed upon the toothing surface. Because the roof structure of the alternate embodiment is to a large extent identical to the structure of the preferred embodiment, only the distinguishing features are discussed hereinafter.
More specifically, FIG. 2 illustrates an inverted roof system 10A having a first water impermeable layer 19A disposed over the toothing surface in an amount sufficient to cover the exposed surface portions of particles 18. Disposed over layer 19A is a second water impermeable layer 19B.
Water impermeable layer 19A is formed from conventional asphaltic or bituminous containing compositions typically employed in roofing arts. For example, hot asphalt, water-based asphaltic emulsions, and solvent-based asphaltic emulsions may be employed for forming layer 19A. In the case where particles 18 comprise gravel of about +1/4 inch, -5/8 inch mesh size applied at the rate of about 150 pounds of gravel per 100 square feet of surface area, an amount of at least about 5 gallons of the material used to form layer 19A is required per 100 square feet of surface area to ensure that the particles 18 are adequately covered and thereby protected from invasion by water.
Because water impermeable layers formed from asphaltic and bitumunous containing compositions are known to be suseptible to cracking, peeling, etc. when exposed to sunlight and/or temperature variations, the water impermeable integrity of layer 19A is enhanced against such occurences by the disposition thereupon of water impermeable layer 19B. Layer 19B is formed from an elastomer containing material which enables said layer to withstand expansion and/or contraction, due to temperature variations, without cracking, thereby protecting against water invasion of the several layers subjacent thereof. An elastomer containing material suitable for use in forming water impermeable layer 19B is the E. I. Dupont product referred to as HYPALON (a registered trademark). A suitable water impermeable layer 19B is formed upon layer 19A by applying an amount of at least about 3 gallons of said product per 100 square feet of surface area. To mitigate sunlight penetration of layer 19B, which penetration would prematurely degrade the structure of layer 19A, an effective amount of radiant energy reflective material is admixed with said product prior to its application upon layer 19A. Titanium dioxide, which results in white tint being imparted to layer 19B, is especially suitable for use as said radiant energy reflective material and results in the additional benefit of reducing heat adsorption by the inverted roof structure 10A.
As a variant of the foregoing, the elastomeric coating 19B can be placed directly on either surface 16 of layer 15 or on the toothing surface 18.
Other examples of suitable elatomers are, e.g., acrylics such as vinyl acrylic polymers, acrylic emulsions, silicones and the like.
It is understood that the above description of my invention is done to fully comply with the requirements of 35 USC 112 and not intended to limit my invention in any way. It can be seen that variant forms of my invention could easily be developed by practitioners skilled in the art. For example, the toothing surface could be eliminated from the composite structure whenever the roof pitch angle is substantially 0°. Inasmuch as this and may other variant forms of my invention are possible, such variant forms are considered to be within the scope and essence of my invention. | A roof structure wherein a water impermeable membrane is fabricated upon a roof deck and a thermal insulation layer affixed upon the membrane. The insulation layer is thereafter coated with a suitable adhesive material and particles of inorganic particulate attached thereto, whereby a toothing surface is formed upon which is applied a mortar based insulative-protective layer. Alternatively, and in lieu of said mortar based layer, a first water impermeable layer formed of bituminous material may be disposed upon said toothing surface, followed by disposition upon said first layer of a second water impermeable layer formed of elastomeric material having radiant energy reflective material admixed therewith. Optionally, said first layer may be omitted from the roof structure and said second layer placed directly on the toothing surface. | 4 |
REFERENCE TO RELATED APPLICATIONS
This is a continuation-in-part application of U.S. Ser. No. 014,152, filed Feb. 12, 1987, which is a continuation of U.S. Ser. No. 559,116 filed Dec. 7, 1983.
BACKGROUND OF THE INVENTION
The invention relates to a method for the production of a textile strip, by preparing and aftertreating an intermediate product, with the textile strip having long weft elements, especially long weft threads, provided diagonally to the strip length, intersecting one another, and connected by longitudinal rows of stitches.
Furthermore, the invention relates to a textile strip, produced according to the method of the invention, as well as to a device on a warp knitting machine, particularly a stitch knitting machine, having at least one movable weft laying device for working long weft elements or weft threads, which extend over the entire working width, into the textile strip.
The invention further relates to a warp-knitting machine, especially a sewing-kitting machine, a production method and a warp-knit fabric. The warp knit fabric may also be referred to as a sloping product.
To connect weft elements with stitch forming warp threads, a warp knitting machine uses a conventional needle system.
A method is known for the production of thread knitted textile strips with diagonally running long weft threads on a warp knitting machine, as well as thread knitting machines which when being used, make it necessary to design the operative width of the weft laying device, so that the distance from the first to the last thread of the weft thread group to be placed corresponds to a one to three and a half time expansion of the working width of the machine (Japanese patent application 42-67693).
If zig-zag like long weft threads are to intersect at an angle of 90°, or if the angle between the weft threads and a fictitious straight line, extending at right angles to the edge of the fabric, is to be 45°, the operative width of the weft laying device (which corresponds to the width of the long weft thread group to be placed) is twice as long as the working width of the machine. If the angle, formed by the long weft threads with the fictitious straight line is 60°, then the operative width of the weft laying device has to be approximately three and a half times the working width. At a working width of 3.5 m, which is the customary width for thread knitting machines, the weft laying device would have to be more than 10 m wide, and correspondingly massive.
Such a weft laying device merely allows a relatively slow mode of operation, which in most cases is not economically justifiable.
The described method is accomplished by a weft laying device, which moves back and forth at right angles in relation to the length of the textile strip. The placed group of long weft threads is guided by two weft thread transport means, into which the long weft threads are hung in the direction of a stitch formation zone, at which point the weft threads join the warp threads, forming a textile strip.
Methods and equipment for the production of warp-knit fabrics or sewn-knitted single sloping products and double sloping products are also known.
For example, as disclosed in U.S. Pat. No. 4,567,738, FIGS. 1 to 4, a single sloping product, comprising a group of filling threads, is produced owing to the fact that a single product with filling threads, which originally are at right angles to the longitudinal axis of the product, are distorted obliquely in an additional production step, to bring about an oblique adjustment of the filling threads relative to the longitudinal axis.
A double sloping product of two groups of filling threads can be produced according to this method by obliquely distorting two single products having filling threads, which are originally at right angles to the product, in separate production steps and subsequently combining them with one another in the nature of warp-knitting or sewn-knitting in yet another production step. At the same time, the single sloping products formed are placed next to one another in such a manner, that the oblique filling threads cross each other. If an additional linear assemblage of fibers is supplied to the two single sloping products before the latter are combined, the double sloping product will have a third structure axis, which is woven on during the process of combining the single sloping products. Because of the separate production of the single sloping products with filling threads originally at right angles and the subsequent treatment of these products, the method is relatively expensive.
A further known method and the equipment associated therewith with (U.S. Pat. No. 4,567,738, FIGS. 5, 6 and 11, and Japanese Patent Application 42-67 693) start out from the idea of producing a warp-knitted or sewn-knitted single sloping product directly, without previously making a single product with filling threads originally at right angles in a separate production process. The method is carried out with a filling laying device, which moves back and forth at right angles to the length of the single sloping product. The laid group of filling threads is guided by two filling-thread transporting means, in which the filling threads are suspended, into a stitch-forming location, where the filling threads are combined with stitch-forming warp threads.
If a rather large angle of slope of the filling threads is desired and the single sloping product is to have an essentially linear edge, it is necessary to design the effective width of the filling laying device in such a manner, that the distance between the first and the last thread of the filling-thread group to be laid is a very long distance, which may be appreciably longer than the working width of the machine. Accordingly, if the filling threads, disposed in zigzag fashion, are to cross each other at an angle of 90°, or if the angle between the filling threads and an imagiary straight line, which extends at right angles to the edge of the fabric, is to amount to 45°, the effective width of the filling laying device (corresponding to the width of the group of filling threads that is to be laid) is twice as long as the working width of the machine. If the angle, which is formed by the filling threads with the imaginary straight line, is 60°, then the effective width of the filling laying device must even be approximately three times the working width.
For a working width of 3.5 m, which is customary for relevant machines, the filling laying device alone would be more than 10 m wide and also correspondingly heavy. A filling laying device with an extended effective width and a corresponding structural size permits only a relatively slow mode of working, which is not economic in most cases.
SUMMARY OF THE INVENTION
It is an object of the invention to suggest additional methods for the production of symmetrical textile strips, which will additionally result in larger economical savings.
It is another object of the invention to produce a method and an apparatus for the production of a textile strip with essentially diagonally running long weft elements, especially long weft threads, making it possible to keep the heretofore used means for the laying of the weft threads over the entire width, maintaining them in their structural magnitudes and mechanical positions, and making them suitable for the intended purpose.
It is yet a further obJect of the invention to provide a warp-knitting and especially a sewing-knitting machine for the direct and inexpensive production of sloping products, which comprises at least one filling laying device, in which the distance from the first to the last thread of the filling-thread group to be laid (effective width of the filling laying device) is dimensioned substantially shorter than the working width of the machine.
A further object of the invention is to point out proposals for new warp-knit fabrics, especially sewn-knitting fabrics, which can be described as single, double or multiple sloping products, and for a method to produce the products.
The objects of the invention are accomplished by initially producing a strip of a weft and warp knit as an intermediate product, having long weft elements, particularly long weft threads, connected by stitches, by subsequently bringing the long weft threads into a very oblique position relative to the strip length, by diagonal displacement of the strip by the weft and warp knit, by doubling the weft and warp knit into two main layers, so that the oblique long weft threads of one main layer of the doubled material intersect the oblique long weft threads of the other main layer, and by finally fastening the two main layers of the doubled weft and warp knit with a top binding consisting of a number of rows of stitches running along the weft and warp knit.
A preferred embodiment of the textile strip, produced according to the method of the invention, consists of two main layers, each consisting of a basic binding with long weft threads connected thereto, with each basic binding having stitch loops on one side and connection stitches on the other side, with the main layers being connected to one another with a basic binding having shorter stitch loops, as well as with a smaller number of needles than is the case with other basic bindings of the main layers.
By means of a warp knitting machine, especially a thread knitting machine for the production of an intermediate product for the textile strip, produced according to the aforementioned method, with the weft laying device being diagonally movable back and forth between two transport chains, an intermediate product can represent the basis for the production of a textile strip, with its long weft threads having a very oblique position from the very beginning without having been diagonally displaced
If this initially very oblique position of the long weft threads is not oblique enough, an increasingly oblique position is achieved by minimal diagonal displacement.
The invention makes it possible to produce a textile strip, in which the oblique long weft threads of one main layer diagonally intersect the oblique long weft threads of the other main layer, without the magnitudes of the weft laying device, common in warp knitting machines, having to be replaced by means which would have to be oversized in dimensions.
The invention enables the effective width of a filling laying device of a warp-knitting machine to be dimensioned substantially shorter than the working width of the machine, while avoiding essentially nonlinear edges of the product. Accordingly, the size of the warp-knitting machine is reduced appreciably and the production speed can be increased.
By means of the warp-knitting machine of the present invention, the warp-knit fabric can be produced directly as an independent single sloping product with filling-thread sections laid obliquely, diagonally and in zigzag fashion or obliquely, diagonally and parallel or as a double sloping fabric with two mutually crossing filling thread layers or as a multiple sloping product with several, mutually crossing filling thread layers. Independent single sloping products can also be united together to produce a different type of double sloping product.
The invention also relates to the production of a double sloping product or of a multiple sloping product with filling thread layers, which do not cross over one another, the layers instead being parallel to one another. Furthermore, other thread assemblages or flat-shaped textile products may be added to all variations of the sloping products and tied into, to or between the respective sloping products. Finally, each single, double or multiple sloping product may be furnished with at least one horizontal layer of filling threads.
The oblique and diagonal filling threads may or may not be disposed to conform to rows of stitches in such a manner, that there is a regular connection between the filling threads and the stitch-forming warp threads.
Thanks to the invention, the production of textile strips can be made much more cost efficient.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood by reference to the accompanying drawings, in which:
FIG. 1 shows a thread knitted weft and warp knit as intermediate product, with the long weft threads being arranged in a slightly oblique fashion;
FIG. 2 is a diagram of the passage of a weft and warp knit through a machine in order to change the position of the long weft threads;
FIG. 3 is a schematic depiction of a section of a textile strip seen from one side, with both main layers of the textile strip being laid together, with the sides carrying the connection stitches of the basic binding, and with the connection stitches of the top binding being visible, as well as the stitch loops of the one basic binding on the top layer and the connection stitches of the other basic binding on the bottom layer;
FIG. 4 is the same as FIG. 3, however, with the side of the textile strip being taken as a front view, showing stitch loops of the top binding, as well as the stitch loops of the one basic connection on the top layer, and the connection stitches of the other basic binding on the bottom layer;
FIG. 5 is a schematic depiction of a section of a strip, taken from one side, with the two main layers of the textile strips with the sides having the stitch loops and the basic binding placed together, and with the connection stitches of the top binding, and the connection stitches of the one basic binding on the top layer, and the stitch loops of the other basic binding provided on the bottom layer;
FIG. 6 is the same as FIG. 5, however, seen from one side of the textile strip, on which the stitch loops of the top binding can be seen, as well as the connection stitches of the basic binding on the top layer, and the stitch loops of the other basic binding on the bottom layer;
FIG. 7 is the same as FIG. 5, but with the top connection being a tricot connection with diagonal connection stitches, and with the basic binding of the two main layers of the textile strip consisting of smaller stitches than the top binding;
FIG. 8 is an additional schematic depiction of a section of a textile strip, in which the main layers are arranged with respect to one another in a staggered fashion, and placed adjacent to one another, so that the connection stitches of the basic binding of the one main layer and the stitch loops of the basic binding of the other main layer touch;
FIG. 9 is the same as FIG. 8, however, not looking at a side of the textile strip, which shows the connection stitches of the top binding, but at a side of the textile strip, which is provided with the stitch loops of the top bindings; and
FIG. 10 is a perspective view of a portion of a warp-knit and especially of a sewing-knitting machine with a filling laying device, which moves back and forth obliquely and diagonally to two chain conveyors, an associated driving mechanism and obliquely and diagonally disposed filling-thread sections, which are processed further in a stitch-forming location to a warp-knit-fabric and especially to a sewn-knitted fabric, the sewn-knitted fabric representing an independent single sloping product.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a weft and warp knit as intermediate product, constructed as thread knitted material. This thread knitted material consists of grouped zig-zag weft threads 1, which extend from one thread knitted fabric edge to the other in the form of long weft threads 1, and of a binding system 2, with which the long weft threads 1 are combined with a weft and warp knit. The long weft threads 1 are arranged in a slightly oblique fashion, and the binding system 2 can consist of any basic binding of warp knitted fabrics. Likewise, combinations of basic bindings can be used to combine the long weft threads 1. A weft and warp knit is furthermore suited as intermediate product for continued processing, with the long weft threads 1 being provided at a right angle to the knitted edges. The base material of the weft and warp knit can also consist of long weft elements 1, such as, for example, foil bands. The threads of the binding system 2 are made from materials which are as smooth and thin as possible, and the long weft threads 1 should be easily displaceable in the binding system 2.
The stitches of the binding system 2 are preferably formed rather long and loose, and the distance from a perpendicular row of stitches to a neighboring row of stitches preferably corresponds to a large number of needles.
The production of the weft and warp knit as intermediate product represents the first process step of the production of a textile strip according to the invention.
The intermediate product is subsequently supplied to a conventional machine 3 in order to change the position of the weft threads in woven fabrics (DD Patent No. 183 987), which can also be used for the displacement of weft and warp knits (FIG. 2). The structure of a weft and warp knit is permanently changed by this machine 3 so that the weft threads or the long weft threads are placed in an oblique position 4 to the perpendicular rows of stitches of the binding system 2. Additionally, when the weft and warp knit is removed from the machine 3, the two thread systems of the weft and warp knit are in the changed position 4' in relation to one another. This is achieved by two chains, grasping the weft and warp knit at the edges, with one chain, because of a special guidance of the same on the way to the working position 5 of the weft and warp knit, eventually remaining behind the other chain. Additionally, the distance between the two chains guided in one area is reduced, since the chain distance at the exit point 5 has to be smaller than at the entrance point 6, because the width of the weft and warp knit decreases with an increasingly oblique positioning of the long weft threads 1.
The result of the passage of the weft and warp knit through the machine 3, according to patent DD No. 133 987, is a sheet, in which long weft threads 1 are subsequently brought into a markedly oblique angle, and which is narrower than the original width of the supplied weft and warp knit. The long weft threads 1 can, for example, be brought into such an oblique position that they form an angle of 45° or, for example, 60°, as compared to a right-angle long weft thread. Every desired angle of the long weft threads 1 can be set. The desired angle 1 of the long weft threads 1 can also be achieved gradually with several passages of the weft and warp knit through the machine 3, in order to change the position of the long weft thread 1. By linking the machine producing theintermediate product with the machine 3 producing the oblique position of the long weft threads 1, there results a synchronized working process.
According to FIG. 3, which shows a section of the textile strip, two unequally long pieces of the main layers 23;24 of the textile strip are sewn or stitched together. The one main layer 23 is the top layer 23 and the other main layer 24 the bottom layer 24. This generally applies for FIGS. 4 to 9 as well. Each main layer 23;24 consists of a weft and warp knit with diagonal long weft threads 1 and a binding system 2, representing the basic binding 2 for the textile strip. One speaks of main layers 23;24, because a weft and warp knit can in itself have several layers and a thread knitted material can, for example, be quasi two-layered. In the case of FIG. 3, both main layers 23;24, i.e., the top layer 23 and the bottom layer 24, have the same basic binding 2--a fringe binding--having stitch loops 2a on the one side of the textile strip and connection stitches 2b on the other side. For the purpose of producing textile goods which contain long weft threads and run diagonally to the strip length and essentially intersect one another diagonally, two main layers 23;24 were doubled by connecting them to one another, so that the angle of crossing of the long weft threads 1 of the main layers 23;24, located either above or below the horizontal line, is, for example, 120°. The doubling of the main layers 23;24 can be accomplished either by folding a strip of the weft and warp knit longitudinally, or by placing two separate next to one another.
Having described the production of the weft and warp knit having very oblique long weft threads 1, the following process steps have been described:
doubling of the strip of the weft and warp knit and
connection of the two components of the doubled strip.
The connection system of the main layers 23;24 will be referred to as top binding. The top binding 25 comprises connection stitches 25a and stitch loops 25b.
In order to clarify FIG. 3, the top binding 25 has been merely provided between the perpendicular rows of the stitch loops 2a of the basic binding 2. In reality, therein a top binding 25 in the area of the basic binding 2 as well. The top binding 25 is a fringe binding. It is self-understood that other bindings can be used in lieu of the fringe binding. The stitch loops 2a of the basic binding 2 can be shorter or longer or equal to the stitch loops 25b of the top binding 25.
It is preferable that the stitch loops 2a in the basic binding 2 be relatively long, when the position of the long weft threads 1 is changed into an oblique position, after having produced the weft and warp knit, since the changed setting of the long weft threads 1 is then easier to achieve. The stitch loops 2a of the basic binding do not necessarily have to have the same length.
The section of the textile strip illustrated in FIG. 3 is furthermore characterized in that the main layers 23;24 are placed next to one another with the sides carrying the connection stitches 2b of the basic binding 2. This applies to the illustration in FIG. 4 as well. In contrast to FIG. 3, the side of the stitch loops 25b of the binding 25 was chosen as the front view. If one combines the main layers 23;24 with their sides carrying the stitch loops 2a of the basic binding 2, the result is patterns, as shown in FIGS. 5 and 6. In these doubled variations, the connection stitches 2b of the basic binding 2 are located on the top layers (main layers). All other characteristics of these patterns are analogous to FIGS. 3 and 4.
The pattern in FIG. 7 essentially corresponds to the pattern in FIG. 5, since the top layer 23 and the bottom layer 24 were laid next to one another, with the sides carrying the stitch loops 2a of the basic binding 2, and the front view shows the connection parts 25a of the top binding 25. The stitch loops 2a and the connection stitches 2b of the basic binding 2 are smaller than the stitch loops 25b and the connection stitches 25a of the top binding 25. Furthermore, a tricot binding is used instead of a fringe binding (FIGS. 3 to 6), in order to connect the top layer 23 and the bottom layer 24, or the two main layers 23;24. The stitch loops 25b are arranged on the bottom side of the illustrated pattern, and have been depicted by a dotted line.
FIGS. 8 and 9 illustrate how the textile strip is designed structurally when the stitch loops 2a of one of main layers 23;24 touch the connection stitches 2b of the other of main layers 23;24, following the doubling of the weft and warp knits. Additionally, it can be noted that the main layers 23;24 are adjacent to one another in a displaced fashion, which is very common.
Furthermore, the textile strip can be produced from more than two main layers 23;24. It is possible to produce interlinings like sheets or warps, on or between the main layers 23;24.
The pattern variations shown in FIGS. 3 to 9 merely represent examples. Especially when changing the direction of the long weft threads 1 and the thickness, a number of additional patterns can be produced as well.
Instead of using the machine 3 for changing the position of the weft threads, an intermediate product can be produced by a special thread knitting machine as well, as illustrated in FIG. 10. The thus produced intermediate product already initially has a very oblique position of the long weft threads 1.
As can be seen, the single sloping product or the sewn-knitted fabric originally already has an oblique layer of filling threads 1. Corresponding to FIG. 10, a filling laying device 8, equipped with a guiding means 7, moves back and forth obliquely between two hook-reinforced chain conveyors 11 and 12 for the purpose of producing this sewn-knitted fabric. In so doing, the filling threads 1, drawn into the filling laying device 8, are suspended as a thread assemblage in the hooks of the chain conveyors 11, 12 and conducted by these through the working location of the sewing-knitting machine. The sewing-knitting process then leads to the production of single sloping products, the filling threads 1 of which are fastened to one another by means of a binding thread system.
The oblique and diagonal position of the filling threads 1 is determined essentially by the adjustment of the guide rods 9, 10 in relation to the chain conveyors 11, 12. The angle of slope of the filling threads 1 is set by the angular setting of the guide rods 9, 10. The guiding means 7 for the filling threads 1 in the filling laying device 8 must be so designed, that it moves parallel to the conveyor chains 11, 12 at least at the sites of movement reversal of the filling laying device 8. Preferably, the filling laying device 8 has a rhomboidal shape.
In the example shown in FIG. 10, consecutive filling thread sections of filling threads 1, aside from being disposed at a sloping angle, are also slightly crossed. In practice, the crossing of the sequential filling-thread sections of the filling threads 1 is about 2° to 5°.
The filling thread layer of the single sloping product or the sewn-knitted fabric is actually formed from a sloping and diagonal zigzag arrangement of a filling thread group (filling threads 1), laid back and forth, the filling thread layer comprising individual, alternately provided filling thread sections of the filling thread group, and the filling thread sections forming different angles of slope with imaginary lines, which should run perpendicularly to the chain conveyors 11, 12. The filling thread sections of the filling thread group mutually overlap partially or cross over one another corresponding to the different angles of slope. Within each of the filling thread sections, the individual filling-thread segments lie parallel to one another.
The layer of filling threads (of the single sloping product or the sewn-knitted fabric) is clearly formed from a sloping or diagonal zigzag arrangement of a filling thread group laid back and forth, the layer of filling threads comprising individual alternately provided filling thread sections B and C of the filling-thread group, which have the group width D of the filling thread group, and the filling thread section B and C forming different slope angles α and β. The vertices of the angles can be set on the chain conveyor 11. On the other hand, it is also possible to start out from angles, which have their vertices on chain conveyor 12, or from other angular relationships, which can be inferred from the representation of FIG. 10 with imaginary lines E, E', which run perpendicular to the chain conveyors 11, 12. Because of the perspective view of FIG. 10, the lines E, E' appear to run obliquely in the drawing. Incidentally, the stitch-for series of knitting needles at the workplace of the sewing-knitting machine runs parallel to the direction of lines E and E'. The horizontal series of stitches of the binding thread system also extend in the same direction. The filling thread sections B and C of the filling thread group partially overlap mutually or cross over one another slightly corresponding to the angles α and β.
If such a crossing is not desired, it is possible to follow the examples of U.S. Pat. Nos. 3,665,732 or 3,756,043. However, in this case, the guide rod for the filling laying device must also be inclined. The filling threads of the single sloping products, which can thus be produced, run parallel to one another and are not crossed in sections. The angle of slope of the filling threads is the same for all filling threads.
A second variation for an independent single sloping product with oblique and diagonal filling thread sections of the filling thread group is thus obtained. This variation differs from the previously treated variation in that the filling thread sections have the same angles of slope and do not mutually overlap. The filling thread sections are disposed consecutively and parallel to one another. The filling-thread segments within the filling-thread sections are also laid parallel to one another. All filling-thread segments are thus present at the same angle of slope.
The filling laying device 8 thus moves, in accordance with the oblique adjustment made, back and forth in this modified direction and, at the motion reversal sites, the thread-guiding means 7 moves, as before, once parallel to the chain conveyors 1, 2 and once in the direction opposite to their running direction. During the forwards and backwards travel of the filling laying device 8 between the chain conveyors 1, 2, the thread guiding means 7 must also, as in the past, carry out a component of motion in the running direction of chain conveyors 1, 2, in order to trail behind the previously laid section of the filling-thread group and to establish connection therewith. Expressed in a greatly simplified form, the thread guiding means 7 passes during each forward and backward travel of the filling laying device 8 through a path of motion, which corresponds to an eight, which lies obliquely as do the guide rods 8, 9. The filling layer formed is joined in the sewing knitting location by means of stitches to the single sloping product.
Single sloping products of the two variations described above may be used, for example, as reinforcing inserts in products where their stabilizing effect in the oblique direction of the filling threads is required.
By means of the invention, the possibility exists of producing warp-knit fabrics and especially sewn-knitted fabrics directly as double or multiple sloping products, without previously having to produce two or more independent single sloping products. The double or multiple sloping products moreover basically have the structures of the laid filling-thread sections of the single sloping products. For this purpose, several pairs of guide rods 9, 10 (the reference symbols of FIG. 10, mentioned at the start of the example of the operation, are used once again now) may be disposed consecutively, each with a filling laying device 8. Accordingly, if two pairs of guide rods 9, 10 are provided, which have different directions, a finished double sloping product with mutually crossing filling-threads 1, tied in obliquely to the fabric length, is obtained after passage of the two prepared layers or thread arrangements of filling-threads 1 through the working site of the sewing-knitting machine. In addition to the two pairs of guide rods 9, 10 mentioned, there exists the additional possibility of installing one or more pairs of guide rods 9, 10 with a filling laying device 8 at right angles between the chain conveyors 11, 12 in order to incorporate one or more other layers or thread arrangements of filling-threads 1, lying essentially at right angles, on and/or into the double sloping product.
It can be inferred longically from the examples described up till now that the sewn knitted fabric, other than as an independent single sloping product with filling-thread sections, laid obliquely, diagonally and zigzag-like or obliquely, diagonally and in parallel, can also be produced as a double sloping product with two mutually crossing filling-thread sections or as a multiple sloping product with several mutually crossing filling-thread layers.
lt is also a question of producing a double sloping product or a multiple sloping product with filling-thread layers, which do not mutually cross but lie parallel to one another. Each single, double or multiple sloping product can be provided with at least one horizontal layer of filling threads.
The filling laying device 8 is driven by a mechanism corresponding to FIG. 10, in which a wirerope 13 is used, the.upper strand of which is connected with the filling laying device 8. Both ends of the rope are attached to the rope drum 14, so that, as the rope drum 14 rotates in alternating directions, one strand of the rope runs on to the drum 14, while the other runs off.
As a consequence of the connection between the filling laying device 8 and the wire rope 13, the filling laying device 8, as already mentioned above, moves back and forth between the two hook-reinforced chain conveyors 11, 12. The rope drum 14 obtains its alternating rotary motion from a shaft 17 over spur-toothed wheels 15, 16. The alternating rotational movement is imparted to the shaft 17 by two endless roller chains 18, 19, between which there is a lifting shaft 20. The ends of the lifting shaft 20 are coupled to the endless roller chains 18, 19. The lifting shaft 20, which is coupled eccentrically with a spur-toothed wheel 21 of relatively large diameter, is moved up and down as the spur-toothed wheel 21 moves in the directions A and B, as a result of which shaft 17 can be caused to rotate in alternating directions. The driving mechanism described thus has the construction and function of a Scotch-yoke mechanism.
If the back and forth motion of the filling laying device 8 is to of be longer or shorter so as to change the working width of the sewing-knitting machine, the eccentric coupling of the crank pin 22 must either be brought closer to or removed further away from the center of motion of the spur-toothed wheel 21. The crank pin 22 on the spur-toothed wheel 21 must also be adjusted when the oblique setting of the guide rods 9, 10 is changed, in order to take into account the change in the path of the filling laying device 8. | Warp knit fabrics, especially sewn-knitted fabrics, are produced by a method and apparatus which results in single and multiple layer sloping fabrics having oblique and diagonal endless filling threads with respect to the boundary of the fabrics. Spaced-apart chain conveyors transport a plurality of filling-thread sections, each of which contains a plurality of endless filling threads, to a stitch-forming site. The plurality of filling-thread sections are held between and transported by the conveyors by a plurality of hooks in the conveyors. Filling thread sections are laid onto the hooks by at least one filling laying device having a guide means for laying the filling thread sections onto the hooks. The filling laying device, guided by a pair of guide rods adjustably positioned obliquely and diagonally with respect to the direction of transportation of the chain conveyors, moves back and forth between the chain conveyors obliquely and diagonally with respect to the direction of transportation of the chain conveyors so that the filling thread sections are laid onto the hooks at an oblique and diagonal angle to the boundary of the fabric. Depending on the number of filling laying devices utilized, and the oblique and diagonal movement of each, single and multiple sloping products are produced wherein filling thread sections within a layer lay parallel to each other or overlap each other at various angles, and different layers of the fabric have mutually-crossing filling thread sections disposed obliquely or perpendicularly to the boundary of the fabric as desired. | 3 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a divisional application of U.S. patent application Ser. No. 10/379,152 filed Mar. 4, 2003 now U.S. Pat. No. 7,485,114, which in turn is a continuation of international patent application PCT/EP01/10189 filed Sep. 5, 2001 and designating the U.S., which claims priority of European Application EP 00 119 179.0, filed Sep. 5, 2000.
FIELD OF THE INVENTION
The present invention relates to a system and a method for the central control of devices, particularly medical devices, which are used during an operation. Specifically, the invention relates to a system controlled by first and second controllers in communication with each other.
BACKGROUND OF THE INVENTION
For ergonomic reasons it is desirable to be able to remote control and control, respectively, the control device of all systems required during an operation from a central position, if possible out of a sterile area. Such a control may be carried out for example via a touch-screen (with a sterile cover) or via a voice control. The controlled devices and systems, respectively, may comprise for example endoscopic devices, as well as an op-table, op-lighting, room lighting, air conditioning, telephone, pager, internet, hospital-information system, consumption parts, management system and so on.
In view of the control of medical devices document DE 199 04 090 A1 for example discloses to interconnect single devices via a CAN-bus, the single devices being used as slaves and a host computer as master. All devices are controllable via this host computer.
The disadvantage of such a network is for example that the software- and hardware-efforts to be taken for the single host computer are very high since it has to be adapted to the device to be controlled having to fulfill the highest safety requirements. In view of devices to be controlled without having to fulfill these high safety requirements it may be possible that flexibility and simplicity of the handling may be lost.
If the single host computer is designed by applying a less stringent standard with respect to safety aspects, the risk would arise (for example for a PC with standard software like Windows-NT), however, said safety-related functions would be endangered by unreliable functions of non safety-related systems.
In this case it is assumed that the mentioned medical devices may be divided into two different groups, namely safety-related systems on the one hand, as for example endoscopic devices (insufflators, pumps, or RF-surgery and so on), op-table-control etc., namely devices or systems which may be life-threatening for a patient in the event of a breakdown or failure, and non-safety-related systems on the other hand, like picture archiving, material management systems, telephone remote control etc.
SUMMARY OF THE INVENTION
In view of the above the object of the present invention is to provide for a system and a method, respectively, which do not have the before mentioned disadvantages. Particularly it is to increase the safety in respect to the control of safety-related devices.
This object is solved by the system of the afore-mentioned kind by providing a second control unit which is connected with the first control unit for exchange of information, and the first control unit is embodied as a closed system for control of at least those devices which carry out safety-related functions (safety-related devices) and the second control unit is embodied as an open system for control of the remaining devices which carry out non safety-related functions (not safety-related devices).
This means in other words that the inventive system does not use a single host computer at has been done up to now, but uses two control units instead which are each assigned to different groups of devices to be controlled. When assigning the devices to be controlled to those control units it is assumed that there are generally devices for carrying out safety-related functions (for example endoscopic devices) and on the other hand devices for carrying out non-safety-related functions, like room lightening, air conditioning etc., during an operation. In this connection the term “closed system” describes a system which does not allow any intervention from outside the system.
Such a system cannot be manipulated, reconfigured etc. neither by a user directly nor via the internet etc. In contrast thereto an open system may be configured or for example supplemented by a user. Here, interventions and manipulations, respectively, from outside are possible.
The advantage of the inventive system is among others that the provision of a further control unit increases the safety with respect to undesired erroneous or faulty functions without limiting the flexibility of the whole system thereby. Due to the fact that on the second control unit software may be used which have not to fulfill such stringent safety requirements as it is the case for the control of safety-related devices, standard software may be used so that the single investment costs on the one hand as well as the running maintenance costs of the total system on the other hand may be reduced.
A further advantage of the inventive system is that the first control unit which is responsible for the control of the safety-related devices is embodied as a closed system which secures that all attempts to manipulate the operating system are disabled. Moreover also manipulations of the applications for controlling the safety-related devices are impossible.
At this point it is to be noted, however, that on the first control unit also applications for control of non safety-related devices could run provided that these applications have been tested under safety aspects before.
Advantageously, those control units are each part of independent computers (PC's). Of course, it is also contemplated that those control units are integrated in one computer which comprises at least two processors (CPU) with one control unit being realized by one processor.
When using a single host computer and considering such requirements it would not be possible to carry out the control of non safety-related devices with the desired simplicity and flexibility. Moreover the risk would always arise that erroneously programmed software for the non safety-related devices would influence the control of safety-related devices.
In a preferred embodiment the first control unit and the safety-related devices are interconnected via a bus-system preferably the Karl Storz-communication-bus (SCB®). Preferably, the non safety-related devices and the second control unit are interconnected via a further bus-system, both bus-systems preferably being different.
These measures result in a simplification of the system as well as to a reduction of the total costs since the especially designed bus-system for safety-related functions is not used for the control of every device. Rather also conventional standard bus-systems may be used. Hence the expensive safety bus-system is only used for the interconnection of the safety-related devices.
In a preferred embodiment an interface unit is provided which is connected with both control units on the one hand and with peripheral devices on the other hand and which connects each of the control units with the peripheral devices. Preferably, the interface unit is controlled by the first control unit via a control line. More preferably the peripheral devices comprise a monitor device and/or an input device, preferably a keyboard and a mouse. More preferably, the monitor device is provided as a touch-screen also allowing an input.
These above mentioned measures result in the advantage that the costs for the total system are reduced on the one hand and the handling is significantly simplified on the other hand since the peripheral devices required for input of control instructions or for monitoring of parameters are provided only once. The surgeon has not to observe plural monitor devices hence. Further, the control line between the interface unit and the first control unit guarantees that the control unit controlling the important safety-related devices also allows the respective necessary function and displays the important safety-related parameters on the touch-screen in case of a breakdown and an failure, respectively, of the second control unit. Altogether, also an increase of the safety level of the system is achieved.
In a preferred embodiment the second control unit comprises a receiving means to capture error messages from the first control unit and to display them on one of the peripheral devices.
This measure has the advantage that also in case of a connection of the second control unit with the interface unit for the control of non safety-related devices error messages concerning safety-related devices are immediately provided to the user of the system. It may hence be avoided that the display of such error messages is only signaled to the user upon re-switching the connection from the first control unit to the peripheral devices. Consequently, this has the advantage that the safety of the total system is further increased.
Preferably the safety-related devices include endoscopic devices, preferably insufflators, pumps, light sources, video devices and for example op-table-controllers etc. The non safety-related devices include for example picture archiving, op-lighting, room lighting, telephone, air conditioning, pager, internet, hospital system, consumption parts, management systems, etc.
It is further preferred to interconnect both control units via an Ethernet-bus (TCP/IP-protocol), since this type of bus-system has been proved as reliable and cost effective.
In a preferred embodiment the first control unit comprises an embedded operating system, preferably “embedded windows NT”, which is protected against interventions from outside the system.
This means in other words that the operating system of the first control unit is a fixed component of the unit and is hence protected against manipulations. The user may not carry out any interventions into the operating system. This would be possible for example with current PC's. Hence, it is avoided that specific safety-related functions cannot be carried out anymore or are carried out erroneously due to intentional or unintentional interventions into the operating system.
In a preferred embodiment the first control unit comprises a check means which cyclically checks the connection with the interface unit and outputs an error message if a connection is not present.
Also this measure results in an increase of safety because the system signalizes the user immediately when a display and a setup, respectively, of respective parameters of safety-related devices are not possible anymore due to the failure of the interface unit.
In a preferred embodiment the first control unit comprises a voice control, for example in form of a software module.
This measure has the advantage that the operation by the surgeon is simplified.
The object underlying the present invention is also solved by a method for the central control of devices used during an operation in that the devices for the control of safety-related functions are controlled by a first control unit and the devices for carrying out non safety-related functions are controlled by a second control unit.
This method allows one to realize the advantages mentioned in connection with the afore-mentioned inventive system in the same manner so that the advantages may not be described here anymore.
In a preferred embodiment both control units communicate with each other, while preferably the first control unit checks the second control unit for faults. It is further preferred to provide for an interface unit which is controlled by the first control unit and which in response thereto forwards signals either from the first or the second control unit to a common peripheral device.
This measure has—as already mentioned—the advantage that the costs of the system are reduced and the ease of operation is increased.
In a preferred embodiment the first control unit will drive the interface unit in case of a failure of the second control unit such that the signals of the first control unit are forwarded to the peripheral devices.
This means in other words that the first control unit ensures that a failure in the second control unit does not result in the breakdown of the connection between the first control unit and the peripheral devices.
In a preferred embodiment the interface unit forwards the signals of the first control unit to the peripheral devices immediately if a safety-related function is to be carried out.
This measure has the advantage that the important functions are possible also when the present connection between the second control unit and the peripheral devices is present. The result is an increase of safety.
In a preferred embodiment the interface unit forwards the signals of the second control unit to the peripheral devices after activating a non safety-related function only when the safety-related function is completed and completely carried out, respectively. This means in other words that the execution of safety-related functions cannot be interrupted by switching the interface unit. Rather, the execution of the safety-related function is carried out up to the end and only than the interface unit will build up the connection between the second control unit and the peripheral devices.
Further advantages and embodiments of the invention can be taken from the following description and the enclosed drawings.
It is to be understood that the features mentioned above and those yet to be explained below can be used not only in the respective combinations indicated, but also in other combinations or in isolation, without leaving the scope of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a schematic block diagram of a system for the central control of devices used during an operation in accordance with the invention.
DETAILED DESCRIPTION OF THE INVENTION
In the FIGURE a system for the central control of devices used during an operation is shown as a block diagram and is indicated with reference numeral 10 . The system 10 comprises a first computer unit 12 and a second computer unit 14 . Both computer units 12 , 14 are interconnected via a bus-connection 16 , for example an Ethernet-bus-connection, in order to exchange data in form of messages.
Both computer units 12 , 14 are provided as medical PC's, wherein the first computer unit 12 uses an embedded operating system, preferably an “embedded windows NT”-operating system. The second computer unit 14 operates preferably with a common windows operating system or another non-embedded operating system.
The first computer unit 12 serves at least for the control of medical devices, which carry out safety-related and safety critical functions, respectively. In the FIGURE, these safety-related devices are indicated with reference numeral 20 . For example, in the FIGURE, a pump 25 , an insufflator 24 and RF generator 26 are shown. This exemplary enumeration of three devices is not to be understood in any limiting sense what is indicated in the FIGURE by further devices n and m. Furthermore, the first computer unit 12 may also be used for the control of non safety-related devices provided that respective tested software is used. However, this possibility will not be further discussed below.
The communication between the first computer unit 12 and the safety-related devices 20 is achieved via a bus-system 28 which allows a safe transmission of data. In view of this bus-system 28 other requirements with respect to fail safety has to be considered as is the case in the afore-mentioned Ethernet-bus 16 . The applicant offers such a bus-system for example under the name Karl Storz-Communication-Bus (SCB®).
The system 10 further comprises a switching unit 30 . The switching unit 30 is connected with its input side to the computer unit 12 and the computer unit 14 , wherein in the FIGURE only one connection line 33 , 35 each is exemplarily shown. It is to be understood that these connection lines 33 , 35 comprise a plurality of single connection lines.
On the output side the switching unit 30 is connected with peripheral devices 40 , wherein in the FIGURE a touch sensitive monitor 42 (called touch-screen), an input keyboard 44 as well as a mouse 46 are shown as an example. The peripheral devices 40 are located for example in the direct sphere of the surgeon in the operation room so that these peripheral devices 40 have to be adapted accordingly. The touch-screen 42 is for example provided with a sterile cover.
The connection of the peripheral devices 40 with the switching unit 30 is made via respective lines 48 , wherein for simplification reasons only one line is shown each representing a plurality of connecting lines.
A switching unit 30 has the task to connect each peripheral device 42 to 46 with one of both computer units 12 , 14 so that the input and the display, respectively, of data is possible.
The control of the switching unit 30 is provided by the first computer unit 12 , and respective control signals may be transmitted to the switching unit 30 via a control line 38 .
The second computer unit 14 is connected (indirect-coupled) with the devices 52 via an optical bus 50 , which devices carry out non safety-related functions. Such functions are for example telephone remote control, room lighting, etc. The control of these non safety-related devices is hence achieved by the second computer unit 14 .
As already mentioned, the first computer unit 12 is equipped with an embedded operating system. This should guarantee that interventions into the systems or manipulations of the systems from outside are not possible. The first computer unit 12 is embodied as a closed system on which only tasks are running which are required for the control of the safety-related devices 20 . Also, tasks may run additionally which serve to control the non safety-related devices 42 in case that these tasks are tested in view of safety aspects before.
The second computer unit 14 is however provided as a common medical PC. In contrast to the first computer unit 12 no tasks are allowed to run on the second computer unit 14 , which tasks serve to control safety-related devices.
Both computer units 12 , 14 supply data by the respective lines 33 , 35 to the switching unit 30 and depending on the “position” of the switching unit only the data of one of both computer units are displayed on the touch-screen 42 . Also the input of data is carried out only in this computer unit. In case that the surgeon wants to select for example functions of the other group of devices, he may do this via a respective input of an instruction which is either directly received by the first computer unit 12 or indirectly received via the computer unit 14 and the bus 16 by the first computer unit 12 . In response thereto it transmits a respective control signal via the control line 38 causing a switching in the switching unit 30 . On the touch-screen 42 the respective data, selecting menus etc. of the selected group of devices will then be displayed.
In case of a connection between the second computer unit 14 with the peripheral devices 40 it is necessary that any error messages relating to safety-related devices 20 are immediately signalized to the surgeon independent of the switch condition of the switching unit 30 via the touch-screen 42 . For this, a task is running in the second computer unit 14 which continuously checks the messages sent by the first computer unit 12 via the bus 16 for failure messages. If an error message is detected the second computer unit 14 ensures that a window is opened on the touch-screen in which the error message is displayed.
A further task of the first computer unit 12 is to check the presence of the switching unit 30 . If the switching unit 30 cannot be detected anymore by the first computer unit 12 for example due to breakdown, the first computer unit 12 must immediately generate an error message. This error message is to signalize the surgeon that an appropriate display and an input of data via the peripheral devices 40 may not be guaranteed anymore.
Further it is necessary that the first computer unit 12 checks the second computer unit 14 and in case of a failure the switching unit 30 is immediately set in those switching conditions in which the first computer unit 12 is connected with the peripheral devices 40 .
Under safety aspects it is also necessary that when inputting an instruction for switching the peripheral devices 40 to the second computer unit 14 all not yet completed functions of the safety-related devices 20 are first completed with a respective display of the parameters. This is to guarantee that the execution of these safety-related functions is not terminated to early. In the reverse case, however the peripheral devices 40 are immediately connected with the first computer unit 12 so that a safety-related function may be carried out without any delay.
It is to be understood that the invention may be realized not only in form of the afore-mentioned embodiment but also in other embodiments. The scope of such modifications is only defined by the appended claims. | The present invention relates to a system for the central control of devices used during an operation, comprising a first control unit for control of said devices. The system is characterized in that a second control unit is provided which is connected to the first control unit for exchange of information. The first control unit may be embodied as closed system for control of at least those devices which carry out safety-related functions (safety-related devices), and the second control unit may be embodied as open system for control of the remaining devices which carry out non safety-related functions (non safety-related devices). The invention further relates to a method for the central control of devices. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 13/557,761, filed Jul. 25, 2012, issued on Oct. 4, 2016, as U.S. Pat. No. 9,458,388, which itself is related to U.S. patent application Ser. No. 12/263,904, filed Nov. 3, 2008, the disclosures of which are incorporated by reference herein in their entirety for all purposes.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable.
BACKGROUND OF THE INVENTION
This invention relates generally to an analyzer based control system and algorithm for the use in a chemical process system. As described for example in U.S. Pat. Nos. 5,503,006, 5,425,267, 5,965,785, 5,326,482, 4,335,072, U.S. Published Patent Applications 2010/0108566 and 2012/0053861 A1, UK Patent 1,198,734, and International Patent Applications 2008/005058, 2004/044266, and 03/006581, chemical and industrial facilities utilize a variety of complex equipment, which are often subject to harsh chemical and physical conditions. As such, a number of technologies have been developed to monitor the condition, efficiency, and expected lifespan of the equipment. Such technologies include historian systems, which collect and archive data from various sources within the chemical plant. U.S. patent application Ser. No. 12/899,250 describes a number of methods of utilizing historian and other data.
Monitoring equipment typically involves a system in which a variety of process variables are measured and recorded. One such system is described in U.S. Published Patent Application 2009/0149981 A1. Such systems however often produce massive amounts of data of which only a small portion of which is usefully tracked to detect abnormal conditions and the information gleaned from those systems is of limited practical use.
In the context of corrosion prevention, three of the most useful data sets for a monitor to measure are pH, metal (especially iron) ion concentrations, and chloride ion concentrations. Ideally the monitored data is as close to real time as possible so remediation techniques for the causes of extreme concentrations can be applied before the causes effect corrosion or otherwise damage the facility. Unfortunately current monitoring technologies provide a large volume of false data so real time monitoring is usually difficult if not impossible. Moreover the false data can lead to the wasting of expensive remedial chemistries when their addition was not needed. As a result a truly automated remedial chemical feed system is not feasible and a human operator is typically required to prevent the addition of remediating chemicals in the face of a “false alarm” thereby increasing operation costs.
Thus there is a clear need for and utility in an improved method of monitoring the conditions within a chemical plant. The art described in this section is not intended to constitute an admission that any patent, publication or other information referred to herein is “prior art” with respect to this invention, unless specifically designated as such. In addition, this section should not be construed to mean that a search has been made or that no other pertinent information as defined in 37 C.F.R. §1.56(a) exists.
BRIEF SUMMARY OF THE INVENTION
At least one embodiment of the invention is directed towards a method of correcting an error in the measurement of a process variable taken by a sensor in a chemical process system. The system is characterized by properties which cause at least some of the measurements to be erroneous. The method comprises the steps of: 1) identifying the component of the error caused by dynamic state factors, this component of the error being determined by at least once obtaining a senor measurement in the system and noting how that measurement deviates from an objectively correct measurement of the process variable by varying amounts relative to time, 2) identifying the steady state factor component of the error, this component of the error being determined by at least once obtaining a senor measurements and noting that the measurement deviates from the objectively correct measurement of the process variable by a fixed amount relative to time, 3) identifying the component of the error caused by additional factors, and 4) altering the measurement to remove the errors caused by steady state factors, dynamic state factors, and unknown factors.
The sensor may be in informational communication with an analyzer and the analyzer may be in informational communication with a controller. The sensor may be constructed and arranged to obtain a raw measurement of the process variable. The analyzer may correct the error in the sensor's measurement. The controller may take the corrected measurement. If the corrected measurement is outside of a pre-determined range of acceptable values, it may enact a remedial measure to change the measured value to a value within the acceptable range. The remedial measure may be enacted before the steady state value of the measurement is detected by the sensor.
The process variable may be a measurement of one item selected from the list consisting of: oxidation-reduction potential, pH, levels of certain chemicals or ions (e.g., determined empirically, automatically, fluorescently, electrochemically, colorimetrically, measured directly, calculated), temperature, pressure, process stream flow rate, dissolved solids and suspended solids.
There may be at least three sensors and each of the three sensors may pass on a raw measurement to the analyzer. The analyzer may use the average of those raw measurements as the input in its calculations if at least one of the raw measurements fits within a pre-determined setpoint expected for the specific conditions under which measurement was taken, the analyzer a historically expected value as the input in its calculations if none of the raw measurements fit within a pre-determined setpoint expected for the specific conditions under which measurement was taken,
The process variable may be iron concentration. The method may further comprise the steps of: disregarding all sensor readings that indicate zero iron concentration, and adjusting the measured iron concentrations using regression analysis over a 1 week time period. The remedial measure may involve adding a chemical whose effect is non-linear in nature. The analyzer may correct for the non-linear effects of the remedial chemical in its corrections. The remedial measure may involve adding a chemical subject to the constraints of deadtime and the analyzer corrects for those effects in its measurements. The process system may be one item selected from the list consisting of: a chemical plant, a refinery, an oil refinery, a food processing facility, a manufacturing plant, a chemical plant, a distillation column, a water filtration plant, a factory, a waste processing facility, a water treatment facility, and any combination thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
A detailed description of the invention is hereafter described with specific reference being made to the drawings in which:
FIG. 1 is a graph which illustrates a method of correcting a measured value of a process variable.
FIG. 2 is a graph which illustrates a method of correcting a measured value of a process variable.
FIG. 3 is a graph illustrating the difficulty in calculating the corrosion rate of a process system.
FIG. 4 is a graph which illustrates a method of correcting a measured value of corrosion rate.
FIG. 5 is an illustration of sources of data used by the analyzer.
FIG. 6 is an illustration of a dashboard containing analyzer output.
DETAILED DESCRIPTION OF THE INVENTION
The following definitions are provided to determine how terms used in this application, and in particular how the claims, are to be construed. The organization of the definitions is for convenience only and is not intended to limit any of the definitions to any particular category.
“Chemical process system” means one or more processes for converting raw materials into products which includes but is not limited to industrial processes which utilize one or more of the following pieces of equipment: chemical plant, refinery, furnace, cracker, overhead column, stripper, filter, distiller, boiler, reaction vessel, and heat exchanger, and the like.
“Dynamic State” means a condition of a measured process variable in which the observed measurement changes over at least a portion of a discrete period of time during which the condition is measured while in fact the actual magnitude of the process variable is not changing.
“Steady state” means a condition of a measured process variable in which the observed measurement remains unchanging over a discrete period of time during which the condition is measured while in fact the actual magnitude of the process variable is not changing.
In the event that the above definitions or a description stated elsewhere in this application is inconsistent with a meaning (explicit or implicit) which is commonly used, in a dictionary, or stated in a source incorporated by reference into this application, the application and the claim terms in particular are understood to be construed according to the definition or description in this application, and not according to the common definition, dictionary definition, or the definition that was incorporated by reference. In light of the above, in the event that a term can only be understood if it is construed by a dictionary, if the term is defined by the Kirk - Othmer Encyclopedia of Chemical Technology, 5th Edition, (2005), (Published by Wiley, John & Sons, Inc.) this definition shall control how the term is to be defined in the claims.
Automation technology plays a significant role in improving and maintaining efficient process operation. It influences the strategic and operational goals of enterprises, their economic results, the development and quality of products, continuity of production, and competitiveness in the marketplace. These strategies should include (1) Improvements of unit operation and (2) Optimizing proper selected chemicals. The key to controlling the corrosion rate is to analyze the corrosion performance and drive the decisive knowledge based on operating data and analyzer measurements. Crude Unit Automation (CUA) system is designed to monitor and analyze the system corrosion and feedback control the chemicals using automation technologies. The implementation of these strategies resulted in lower corrosion risk and continued improvement of the run length of the overhead heat exchangers.
In at least one embodiment of the invention, the control system in use in the process system comprises two elements: (1) at least one sensor and (2) at least one analyzer. In at least one embodiment of the invention, the control system comprises three elements: (1) at least one sensor, (2) at least one analyzer, and (3) at least one controller. The sensor(s) is constructed and arranged to measure at least one process variable within at least one portion of the system.
The analyzer receives the measurement taken by the sensor and converts it into information which can be output. The controller receives the output and can cause some operation to occur in response to the output.
In at least one embodiment the response includes adding a chemical. Added chemicals may include neutralizer, filmer, caustic, and inhibitors and so on and are used to control corrosion process variables. The analyzer provides on-line measurements of process variables (especially pH, [Cl] and [Fe]). The analyzer provides output which is used to monitor, analyze and manage the whole system.
In at least one embodiment some or all of the information is displayed on a dashboard. The dashboard can also display how the system manages historian database data, reports, alarms, and make readily available the user's selected strategy for real time control and optimization of the crude unit system.
In at least one embodiment the system is a closed loop which utilizes preliminary analysis of historian and archived data, updates from the analyzer and other diagnostics (such as personal observations and discussions with operating staff) to then generate responses and further analysis of the crude unit's operations.
In at least one embodiment the use of inhibitors is to prevent or to reduce general corrosion, and it plays an important role in the control of corrosion for those areas in which general corrosion is the problem. The objective of the control system is how to prevent/reduce corrosion in crude unit overhead by controlling the inhibitors. As one of the main components of a crude unit process, corrosion control plays a vital role in maintaining system integrity. This invention provides a way to optimize the corrosion control component of the crude unit through optimizing one or more system parameters in a process stream of the crude unit. This optimization includes measuring properties associated with those parameters in the process stream.
In at least one embodiment the analyzer is designed to reduce corrosion of refinery processing equipment and subsequent fouling due to deposition of corrosion byproducts. A typical corrosion control program includes components such as a neutralizing amine, a filming inhibitor, a caustic solution, etc. Such corrosion control chemicals are traditionally injected into the system based upon measurements derived from grab samples and analyzed in the lab or some flow indication on the unit. This invention provides an automated method of adjusting chemical injection into the system.
In at least one embodiment, the method of the invention includes a controller operable to receive and process information and provide instructions to various components (e.g., chemical injection pumps). The term “controller” refers to a manual operator or an electronic device having components such as a processor, memory device, digital storage medium, cathode ray tube, liquid crystal display, plasma display, touch screen, or other monitor, and/or other components. The controller is preferably operable for integration with one or more application-specific integrated circuits, programs, computer-executable instructions or algorithms, one or more hard-wired devices, wireless devices, and/or one or more mechanical devices. Moreover, the controller is operable to integrate the feedback, feed-forward, or predictive loop(s) of the invention. Some or all of the controller system functions may be at a central location, such as a network server, for communication over a local area network, wide area network, wireless network, interne connection, microwave link, infrared link, and the like. In addition, other components such as a signal conditioner or system monitor may be included to facilitate signal transmission and signal-processing algorithms.
The controller may include hierarchy logic to prioritize any measured or predicted properties associated with system parameters. For example, the controller may be programmed to prioritize system pH over chloride ion concentration or vice versa. It should be appreciated that the object of such hierarchy logic is to allow improved control over the system parameters and to avoid circular control loops.
In at least one embodiment, the method includes an automated controller. In another embodiment, the controller is manual or semi-manual. For example, where the crude refining process includes one or more datasets received from a various sensors in the system, the controller may either automatically determine which data points/datasets to further process or an operator may partially or fully make such a determination. A dataset may include process variables or system parameters such as oxidation-reduction potential, pH, levels of certain chemicals or ions (e.g., determined empirically, automatically, fluorescently, electrochemically, colorimetrically, measured directly, calculated), temperature, pressure, process stream flow rate, dissolved or suspended solids, etc. Such system parameters or process variables are typically measured with any type of suitable data capturing equipment, such as pH sensors, ion analyzers, temperature sensors, thermocouples, pressure sensors, corrosion probes, and/or any other suitable device or method. Data capturing equipment is preferably in communication with the controller and, according to alternative embodiments, may have advanced functions (including any part of the control algorithms described herein) imparted by the controller.
Data transmission of measured parameters or signals to chemical pumps, alarms, or other system components is accomplished using any suitable device, such as a wired or wireless network, cable, digital subscriber line, internet, etc. Any suitable interface standard(s), such as an ethernet interface, wireless interface (e.g., IEEE 802.11a/b/g/x, 802.16, Bluetooth, optical, infrared, radiofrequency, etc.), universal serial bus, telephone network, the like, and combinations of such interfaces/connections may be used. As used herein, the term “network” encompasses all of these data transmission methods. Any of the described devices (e.g., plant archiving system, data analysis station, data capture device, process station, etc.) may be connected to one another using the above-described or other suitable interface or connection.
In at least one embodiment, system parameter information is received from the system and archived. In another embodiment, system parameter information is processed according to a timetable or schedule. In a further embodiment, system parameter information is immediately processed in real-time/substantially real-time. Such real-time reception may include, for example, “streaming data” over a computer network.
In at least one embodiment two or more samples are taken at different locations in the system. For example one could be at the dew point and one at the boot accumulator. The measurement differences at these two sample points require a corresponding algorithm to adjust chemical injection. The term “dew point” refers to the point of initial condensation of steam to water or the temperature at which a phase of liquid water separates from the water vapors and liquid hydrocarbons and begins to form liquid water as the vapors cool. Though possible to use the accumulator water boot to measure pH and chloride ion level, a level of accuracy is usually sacrificed because data is diluted or masked by the full volume of steam and weak acids and bases that have condensed downstream of the water dew point.
Likewise, it is possible to measure iron (or other metals, such as copper, molybdenum, nickel, zinc) ion concentration from the dew point water. In at least one embodiment the metal ion concentration is measured at the accumulator water boot because these ions indicate corrosion has taken place and metal has been removed from an internal component in the system upstream of the sample point.
It should be appreciated that any suitable method may be used for obtaining the dew point water sample. For example, devices for obtaining the dew point water sample are disclosed in U.S. Pat. No. 4,335,072, titled “Overhead Corrosion Simulator” and U.S. Pat. No. 5,425,267, titled “Corrosion Simulator and Method for Simulating Corrosion Activity of a Process Stream,” each of which is incorporated herein by reference in its entirety.
In at least one embodiment, different fluid or system parameters or process variables or other constituents present in the system could be measured and/or analyzed including but not limited to pH; chloride ion; other strong and weak acids, such as sulfuric, sulfurous, thiosulfurous, carbon dioxide, hydrogen sulfide; organic acids; ammonia; various amines; and liquid or solid deposits and the like. Various methods of taking measurements are contemplated and the invention is not limited to one particular method. Representative methods include, but are not limited to those disclosed in U.S. Pat. Nos. 5,326,482, 5,324,665, and 5,302,253.
In response to the measurements taken at various locations in the system remedial chemistry can be added to the system to respond to the measured readings. Such remedial chemistries include but are not limited to neutralizers, filming inhibitors (sometimes referred to herein as “filmers”), and caustic agents. These points are labeled “Neutralizer based on acid or pH,” “Filmer based on iron,” and “Caustic based on chloride.” It should be appreciated that such chemicals may be added at any suitable location in the system. In at least one embodiment, introduction of such chemicals into the system are adjusted continuously. In other embodiments, chemical introduction is adjusted intermittently or in relation to a schedule as determined for each individual system.
Neutralizer(s), caustic agent(s), and filming inhibitor(s) may be introduced to the system using any suitable type of chemical feed pump. Most commonly, positive displacement injection pumps are used powered either electrically or pneumatically. Continuous flow injection pumps are sometimes used to ensure specialty chemicals are adequately and accurately injected into the rapidly moving process stream. Though any suitable pump or delivery system may be used, exemplary pumps and pumping methods include those disclosed in U.S. Pat. No. 5,066,199, titled “Method for Injecting Treatment Chemicals Using a Constant Flow Positive Displacement Pumping Apparatus” and U.S. Pat. No. 5,195,879, titled “Improved Method for Injecting Treatment Chemicals Using a Constant Flow Positive Displacement Pumping Apparatus,” each incorporated herein by reference in its entirety.
Representative neutralizers include but are not limited to 3-methoxypropylamine (MOPA) (CAS #5332-73-0), monoethanolamine (MEA) (CAS #141-43-5), N,N-dimethylaminoethanol (DMEA) (CAS #108-01-0), and methoxyisopropylamine (MIOPA) (CAS #37143-54-7).
As a caustic agent, a dilute solution of sodium hydroxide is typically prepared in a 5 to 10% concentration (7.5 to 14° Baume) for ease of handling and to enhance distribution once injected into the crude oil, or desalter wash water, for example. Concentration may be adjusted according to ambient conditions, such as for freeze point in cold climates.
Filming inhibitors or filmers used in conjunction with this invention in a crude unit corrosion control program are typically oil soluble blends of amides and imidazolines. These compounds offer good corrosion control with minimal effects on the ability of the hydrocarbons in the system to carry water.
It should be appreciated that a suitable pH control or optimal range should be determined for each individual system. The optimum range for one system may vary considerably from that for another system. It is within the concept of the invention to cover any possible optimum pH range.
In different embodiments, changes in the neutralizer pump are limited in frequency. Preferably, adjustment limits are set at a maximum of 1 per 15 min and sequential adjustments in the same direction should not exceed 8. For example, after 8 total adjustments or a change of 50% or 100%, the pump could be suspended for an amount of time (e.g., 2 or 4 hours) and alarm could be triggered. If such a situation is encountered, it is advantageous to trigger an alarm to alert an operator. Other limits, such as maximum pump output may also be implemented. It should be appreciated that it is within the scope of the invention to cause any number of adjustments in any direction without limitation. Such limits are applied as determined by the operator.
It should be appreciated that a suitable or optimal chloride ion concentration range should be determined for each individual system. The optimum range for one system may vary considerably from that for another system. It is within the concept of the invention to cover any possible optimum chloride ion concentration range.
In at least one embodiment other metallurgy is used so such as monel, titanium, brass, etc. may be used in some systems. In these cases, rather than an iron ion concentration signal, the appropriate metal ion (e.g., copper, nickel, zinc, etc.) concentration signal would be detected and analyzed.
Metal ions commonly exist in two or more oxidation states. For example, iron exists in Fe 2+ and Fe 3+ as well being present in soluble states (ionic and fine particulate), insoluble states (i.e., filterable), etc. Analysis and control of metal ions includes measurement or prediction of any combination (or all) of such permutations present in the system.
Although the corrosion probes (e.g., electrical resistance corrosion probes, linear polarization probes, and/or any other suitable method for determining metal loss) may be placed at any convenient location in the system, preferably they are placed in historically reliable locations in the system. In addition, if, for example, 2 overrides are activated over a 12 hr period, a reliability check is typically initiated to ensure that the corrosion probes are operating properly. If such a situation is encountered, it is advantageous to trigger an alarm to alert an operator. Other limits, such as maximum pump output may also be implemented. It should be appreciated that it is within the scope of the invention to cause any number of adjustments in any direction without limitation. Such limits are applied as determined by the operator.
In at least one embodiment, if the communication link between the analyzer and the controller is severed or impaired, the controller continues with whatever action it was undertaking prior to losing communication. In at least one embodiment, if the communication link between the analyzer and the sensor is severed or impaired the controller continues with whatever action it was undertaking prior to losing communication. In at least one embodiment, if the analyzer output induces the controller to enact a response beyond the physical limitations of the equipment, the controller the best response possible (such as turning on/off one or more pumps, vents, drains, lifts, stators, conveyers, furnaces, heat exchangers . . . etc.) and the controller keeps that underperforming responding equipment running at its maximum capacity until the analyzer output warrants a reduction. In at least one embodiment at least one piece of responding equipment is constructed and arranged to respond to analyzer output only gradually. In at least one embodiment while the equipment can respond only gradually, it is constructed and arranged to return to its pre-response setting as soon as physically possible. This allows for the negation of an incorrect response before the response has caused a significant effect. An example of gradual response is a pump that increases the flow of chemical from 0% of a maximum flow rate to 100% of maximum flow rate over the course of up to 10 minutes even though it can reach 100% within a few seconds.
In at least one embodiment the analyzer utilizes a model method of data analysis to correct for inaccuracies that occur in the measurements of process variables. Because corrosion is by definition the result of a finite amount of mass from the plant equipment detaching from those pieces of equipment, the amount of corrosion measured should be easy to correlate with physical damage to components of the system. However due to large amounts of noise inherent in such facilities the measured rates, fluctuate widely and are often not accurate. Significantly the noise often leads to measured corrosion rates greater than the actual mass that has been removed from the equipment. In addition different forms of crude oil (especially opportunity crude) and inconsistencies in their composition cause equipment to often function differently during different production runs. This leads to varying and hard to predict rates of corrosion. Moreover as corrosion changes the very environment being analyzed each production run may make further ambiguous future analyses.
In at least one embodiment the analysis takes into account the known difference between the steady state measurement and the dynamic state measurement taken by the sensor to correct for inaccuracies that occur in the measurements of process variables. As illustrated in FIG. 1 , in many situations a disturbance in the system (such as turning on or off a pump, adding or ceasing addition of a chemical, changing pH, [Fe], temperature, pressure, etc . . . ) causes a short term dynamic state change in the sensor measurement as well as a longer term steady state change in the sensor measurement. The analyzer learns to associate the specific dynamic state changes that occur in response to specific disturbances with specific sensors and when under those conditions it detects a similar dynamic measurement, instead of outputting the detected measurement the analyzer outputs the corrected value that it has learned is associated with the properties of the detected dynamic state.
As a result, in at least one embodiment the output of at least one sensor measurement of a process variable obtained by the analyzer undergoes a conversion. That output can be represented by the function:
u =ƒ( e,Δe,d )
in which u is output of the analyzer measuring a process variable, e is the error detected in the dynamic state, d is the magnitude of the disturbance that caused the error, and Δe is the change in the error over time. The error itself can be calculated using the equation:
e=SP−PV
in which PV is a process variable, or the actual value that the analyzer measured for the variable and SP is the setpoint or what the value should have been but for the disturbance based noise.
In at least one embodiment the specific parameters of any predictive function used to correct for a measured process variable can be calculated through direct observation of the system.
Utilizing the above equations, one of ordinary skill in the art would recognize that based on a Taylor series expansion,
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where u 0 denotes steady state controller output; e 0 , Δe 0 , and d 0 are e, Δe and d. The controller consists of two parts: steady state, u 0 =ƒ(e 0 , Δe 0 , d 0 )and dynamics ƒ(e), ƒ(Δe), ƒ(d). The steady state can be obtained from direct measurements of the system steady state. In at least one embodiment at steady state at least one of e 0 , Δe 0 , and d 0 are e, Δe and d is 0.
The dynamic part is approximated by the following nonlinear dynamic model:
Δ represents lumped uncertainties and other unmodeled terms. In at least one embodiment it can be attenuated by control technology because it is bounded.
At steady state, u 0 is known by human experience, or it is easy to know by test or simple analysis and modeling. One useful meaning of u 0 is the result of the ideal pump output when the controlled variable is at its target. Each dynamic part ƒ is a tunable function based on specific process, the function is also knowledge based and within a control limits [u min , u max ]. In at least one embodiment the function is designed according to a proportional format. In at least one embodiment the function is designed according to a sigmoid format.
In at least one embodiment the system comprises output limits and the variable limits ┌PV min , PV max ┐ to designate the boundaries permissible by system control. In practice, u min =u 0 −U c ; u max =u 0 +U c ; PV min =SP−SP c ; PV max =SP+SP c , where U c is a output scale factor which is a constant tuned on-line, SP c is the variable scale factor which is a constant tuned on-line.
In addition, the resulting changes in the system due to feeding chemicals needs to be predictable. Precise control of pH and corrosion is quite difficult due to large variations in process dynamics. One difficulty arises from the static nonlinear relationship in results of chemical additions such as titration. Titration is the relationship between pH of a medium and the concentration of acids and bases in that medium. The nonlinearity in titration depends on the substances in the solution and their concentrations. For example the presence of some weak acids or weak bases causes a buffering effect (a resistance to proportional changes in pH despite proportional changes in the concentrations of acids and bases).
Other chemistries present in the process system may also have non-linear responses to added chemicals. In addition because of the ebb and flow rate of operations in a process system, there are very long periods of deadtime. As previously mentioned u 0 can be represented by the result of the ideal pump output when the controlled variable is at its target. In practice however due to sizes, distances that the chemicals must traverse, and other physical constraints, the pump is in fact not ideal and there is a significant lag between when the instruction is given to feed a chemical, and when the chemical appears in the system in a dosage significant enough to appropriately affect the system. For purposes of this application, the time lag between activating a pump and the pump causing the proper effect is known as “deadtime.” During deadtime a number of changing dynamics occur which lead to wildly inaccurate measurements of process variables.
In at least one embodiment the analyzer utilizes a combination of human knowledge and experience to adjust feed rates to take into account the nonlinear properties the controller must address. This makes the controller more intelligent and feasible.
The presence of other materials in the process system often affects the nature of various acids further complicating any attempt to predict resulting pH from changing the concentrations. As a result, if graphed, the shape of the expected titration curve becomes quite irregular. In at least one embodiment, by disregarding noise and error, the analyzer can accurately model and predict the correct titration curves is required for effective pH control.
As a result, a method of signal processing may need to be utilized to correctly measure a process variable. Suitable forms of signal processing include but are not limited to DSP algorithms, filtering (including low pass, high pass, adaptive, and moving average filters), smoothing, ARX, Fourier transform, S-plane analysis, Z-plane analysis, Laplace transforms, DWT, wavelet transforms, bilinear transforms, and Goertzel algorithms. In at least one embodiment analysis using dynamic state error is done prior to the signal processing. In at least one embodiment analysis using dynamic state error is subsequent to the signal processing.
Signal processing is of particular benefit with regards to detecting Fe. One particular error involves the trend of iron detection to drop to zero. This reading is obviously erroneous. As a result, if the signal processing does not correct for zero concentration of Fe in a system that obviously contains Fe due to ongoing or previous corrosion, the analyzer will correct the iron reading to what its learned experience indicates it should be and/or to what the reading was immediately before it began its drop to zero. In at least one embodiment, if the sensor detects zero iron the analyzer does not pass on the detected iron value to the controller but instead passes on a value based on what the iron level should be based on previous performance under similar conditions.
In at least one embodiment the control system comprises one or more methods, compositions, and/or apparatuses described in Published U.S. Patent Application 2012/0053861 A1.
In at least one embodiment the control system comprises one or more redundant sensors detecting the same process variable at substantially the same location in the process system. Because much of the noise causing inaccuracies is random in nature, the errors do not always affect all the sensors at the same time. As a result under certain circumstances a minority of sensors may be erroneous and a majority may be correct. In at least one embodiment if all of the sensors provide readings consistent with pre-determined setpoints based on the specific conditions present, the analyzer returns the average measurement to the controller. In at least one embodiment if at least one of the sensors provides measurements consistent with the setpoints, the analyzer returns the average measurement of the consistent measurements to the controller. In at least one embodiment if all of the sensors provide measurements inconsistent with the setpoints, the analyzer rejects all of the measurements and instead passes on to the controller measurements based on historical data until at least one sensor again provides consistent measurements. In at least one embodiment the historical data will be the average of some or all previous measurements consistent with the setpoints.
In at least one embodiment, the analyzer's variable sampling period is much longer than that of normal transmitters, (in some cases as high as 60 minutes). In addition, the controlled variable expectations (setpoints) are normally in a range instead of a single point.
In at least one embodiment remedial chemistry or process chemistry fed by the controller is added according to a feedforward model. Feedforward can best be understood by contrasting it to a feedback approach. In feedback the receipt of information about a past event or condition influences the same event or condition in the present or future. As a result the chain of cause and effect forms a circuit loop that feeds back into itself.
In a feedforward model the reaction to the information occurs before the actual information is received. This allows for faster reaction to system problems, reducing the duration, severity, and consequences of unwanted conditions. Feedforward can be achieved using the same observations that are used to determine the analyzer output function. Specifically because the analyzer changes the output to the correct value before the correct value is detected by the sensor (in some cases while it is still receiving dynamic state changing information.) Moreover feedforward allows for the elimination of conditions that would otherwise persist during the deadtime between the actual existence of an unwanted condition and the delays caused by inaccurate measurements and imperfect pump flow properties. In at least one embodiment the feedforward strategy addresses an unwanted system condition faster than a feedback system can.
In at least one embodiment the feedforward model is used to analyze the variable relationship and eliminate the interactions. For example, in a crude oil refinery logic used to determine if corrosion control measures needs to be enacted in response to Fe concentration would be governed by a feedforward model reacting to analyzer output according to a function of (Caustic, Neutralizer). This control algorithm provides whole functionalities and capabilities to implement feedforward model. In at least one embodiment the properties of the feedforward strategy is included in the controller algorithm. The format of the controller algorithm its data analysis can be designed based on specific properties of the system it is used within.
As previously mentioned because corrosion is due to loss of mass in process equipment, by definition the detected amounts of corrosion should equal the lost mass. Because that however is not what the sensors often detect, special measures need to be taken by the analyzer to correct the detected levels of corrosion. In at least one embodiment the corrosion rate (CR) is corrected by the analyzer by taking into account both on-line detected levels and an analysis of the corrosion rate.
In at least one embodiment this analysis makes use of two definitions of CR, instant CR and period CR. Both of the two rates reflect different aspects of corrosion speed. Instant CR is defined as the rate of metal loss change at a specific fixed period of time, e.g. one day or week. In at least one embodiment a corrosion probe (the sensor) is used to detect a raw value. Due to the noisy signal inherent in such detections, a linear regression or other form of signal processing may be used to correct the detected value of Instant CR. Instant CR provides insight into instantaneous causes of corrosion which is extremely helpful in determining the effect of changes in the process system conditions.
In at least one embodiment Period CR requires several days or weeks to determine the general corrosion rate. Period CR is determined by identifying which linear function best represents the metal loss in such noisy environment. A simple linear calculation is based on two points of beginning and end, this calculation assumes the metal loss is monopoly increased function, does not consider the data between the two points. Obviously, this calculation does not reflect real situation under noisy signals, most likely, this calculation is far away from reality. A proper linear curve is generated by least squares regression, which minimize the total distances between each point to the linear curve.
min Σ(y−Y i ) 2
where Y represents the linear curve we design; Yi denotes real probe reading at i point. FIGS. 3 and 4 show compared corrosion rates based on two point corrosion reading, two point filtered corrosion reading, and linear regression. Essentially, the corrosion rate is the slope of the linear curve, it shows how big discrepancy of the three calculations, and also we can understand which calculation is more reasonable and scientific. As shown in FIG. 3 , using a linear analysis of detected corrosion rates over the period can result in multiple rates based on which form of analysis is used.
As illustrated in FIG. 4 , in at least one embodiment the use of the linear representation of the average regression curve is used to identify the actual rate of corrosion that occurs in the system.
In at least one embodiment the decision regarding which linear representation to use is constantly updated to best reflect observations made of the system.
Referring now to FIG. 5 there is shown a logical flowchart illustrating how information from various sources is constantly fed to and used by the analyzer to improve the logic it uses to correct for incorrect readings. The analyzer utilizes:
(1) On-line and off-line filter design to smooth noisy corrosion probe reading and exclude outliers, (2) corrected definitions of corrosion rates (instant running rate, period rate) and their relationship to each other. This gives different definitions to calculate and compare. (3) On-line (running regression CR) and off-line corrosion rate calculation and monitoring and alarming corrosion rate. (4) Corrosion rate evaluation and analysis, used by the controller, and (5) automatically generated analysis reports.
In at least one embodiment the control system makes use of on-line measurements of Process changes in one or more of temperature, pressure, velocity and concentration to detect acceleration in corrosion rate. This can be done by making use of instant CR and period CR.
In at least one embodiment the analysis is according to the following equations: Instant CR=dy/dt. Therefore:
Instant
CR
=
dy
dt
=
lim
Δ
t
->
0
Δ
y
Δ
t
Because Period CR can be said to be the rate of metal loss change at a fixed period of time, such as Δt or Δy/Δt. However, because of the signal “noise” that accompanies metal loss y, if a linear regression of y is first used and then Period CR is calculated as the slope with time Δt then:
Period
CR
=
Δ
y
Δ
t
Instant CR and Period CR reflect different aspects of corrosion speeds. In at least one embodiment Period CR is determined over several days or weeks to determine the general corrosion rate; Instant CR is instantaneous corrosion which is extremely helpful in determining the effects of process changes on corrosion.
In at least one embodiment the relationship between Instant CR and Period CR is determined by an integral mean-value theorem. For example:
Period
CR
=
Δ
y
Δ
t
=
y
t
2
-
y
t
1
t
2
-
t
1
=
∫
t
1
t
2
dy
dt
dt
t
2
-
t
1
=
dy
dt
ξ
(
t
2
-
t
1
)
t
2
-
t
1
=
dy
dt
ξ
In which there exist a point ξ in [t1, t2] where the instant CR will be the same as the Period CR. This point however will not necessarily be the mean, median, mode, and/or average of Instant and Period CR.
Although the corrosion process is very complex, under certain circumstances the corrosion rate can approximate a simple linear function of time t, according to the equation: y=at+b
where y is the monopoly metal loss function; t is time, and a and b denote the slop and bias of the function. Both a and b are all time-invariant constants.
Under this approximation:
Instant
CR
=
∂
y
∂
t
=
a
=
Δ
y
Δ
t
=
y
-
y
0
t
-
t
0
=
Period
CR
This illustrates that if and only if the slope and bias a, b are unchanged constants in the period of time Δt then Period CR will be equal to Instant CR.
As shown in FIG. 6 , in at least one embodiment the analyzer outputs information into a dashboard format that provides a user with a helpful and easy to understand perspective on the operations of at least a portion of the system. For example the various detected performance variables can be expressed according to a relative evaluation indicating how well or poor the system is doing.
In at least one embodiment the evaluation will be expressed according to at least one of the following categories:
Control Variable Stability
Variable stability is very critical for process operation. In crude unit corrosion control system, three critical variables (pH, Cl, Fe) are the key to maintain the corrosion system stable. Daily cpk is used and compared.
Chemical Usage
Neutralizer, Caustic and Filmer are used to control the three controlled variables, pH, Cl and Fe. One of objectives of this control design is to maintain the controlled variables while saving the chemical usages.
Evaluation on Automation System Operation
The system not only provides the key variable measurement by the analyzer, but also (1) The system provides whole information, include pumps, boot water pressures, working temperatures, inferred chemical flow rates, corrosion . . . (2) Provides friendly interface, gives us a platform to remotely monitor and operate the whole system, modify parameters . . . (3) Collects analyzer alarms, generates/sets all variable operation alarms, and provides instant cell phone and email alarms, (4) Provides a platform of on-line and off-line data analysis and translating information into refined knowledge . . . , this is the spotlight of the system, (5) The control system on stream time is 100% except some events happened.
Corrosion Performance Analysis
On line corrosion rate must be calculated and compared with other variables. FIG. 7 gives an example of a weekly period corrosion rate based on two probes. FIG. 8 shows an evaluation demonstrating that the corrosion rate is strongly correlated to the critical variables Fe and pH.
In at least one embodiment the process system that the control system in used within contains at least one of a crude unit, de-salter, atmospheric tower, vacuum tower, cooling unit, heating unit, furnace, cracker, and any combination thereof. The control system will optimize and improve the performance of some, part or all the components of the process system. Such improvement will (1) Improve and maintain process stability and reliability. (2) Optimize chemical usages and reduce cost. (3) Improve system robustness, operating flexibility, provide reliable information system and friendly low-cost interface. (4) Define, calculate, monitor, control and optimize corrosion rate.
In at least one embodiment, not only does the control system determine and predict the corrosion in the aqueous phase of a crude unit overhead system but it can also calculate and predict the formation of salts as well as their impact of corrosion. In at least one embodiment, the analyzer can calculate in real time the amount of additive (amine) to inject to remedy the impact of salts on corrosion.
In at least one embodiment this calculation is achieved by using at least one of the following inputs: pH, chloride, temperature, pressure, density, flowrate, wash water rate, total steam, and the presence of the following compounds: Chloride, total amine, total nitrogen, halogen, bromide, iodide, oxygen, water, and ammonia level. In at least one embodiment this is accomplished by the addition of and observation of the reaction of one or more of the following amines: methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, n-propylamine, isopropylamine, di-n-propylamine, di-isopropylamine, n-butylamine, sec-butylamine, 1-amino-2,2-dimethylpropane, 2-amino-2-methylbutane, 2-aminopentane, 3-aminopentane, morpholine, monoethanolamine, ethylenediamine, propylenediamine, N,N-dimethylethanolamine, N,N-diethylethanolamine, N,N-dimethylisopropanolamine, Methoxyethylamine, Piperidine, Piperazine, Cyclohexylamine, N-methylethanolamine, N-propylethanolamine, N-ethylethanolamine, N,N-dimethylaminoethoxyethanol, N,N-diethylaminoethoxyethanol, N-methyldiethanolamine, N-propyldiethanolamine, N-ethyldiethanolamine, t-butylethanolamine, t-butyldiethanolamine, 2-(2-aminoethoxy)ethanol, di-n-butylamine, tri-n-butylamine, di-iso-butylamine, ethyl-n-butylamine, pentylamine, 2-amino-2,3-dimethylbutane, 3-amino-2,2-dimethylbutane, 2-amino-1-methoxypropane, dipropylamine, monoamylamine, n-butylamine, isobutylamine, 3-amino-1-methoxypropane, and any combination thereof.
Using sensors to detect pH, Chloride, Fe, as well as at least one nitrogen sensor, at least one total nitrogen sensor or the combination thereof, a mathematical model can calculate the formation of salt and or corrosive species. This information and the corresponding calculations can be made in real time from a sample collected in real time. The calculated and stored information can then be used to calculate and control the addition of additives in real time into the overhead based on the corrosive nature and composition of the compounds present in the overhead.
In at least one embodiment the control system can continuously recalculate in real time the corrosive conditions; the salt formation and have the controller add appropriate additives should any one-parameter change. These additives include but are not limited to: Water, Sodium
Hydroxide, potassium hydroxide, lithium hydroxide, methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, n-propylamine, isopropylamine, di-n-propylamine, di-isopropylamine, n-butylamine, sec-butylamine, 1-amino-2,2-dimethylpropane, 2-amino-2-methylbutane, 2-aminopentane, 3-aminopentane, morpholine, monoethanolamine, ethylenediamine, propylenediamine, N,N-dimethylethanolamine, N,N-diethylethanolamine, N,N-dimethylisopropanolamine, Methoxyethylamine, Piperidine, Piperazine, Cyclohexylamine, N-methylethanolamine, N-propylethanolamine, N-ethylethanolamine, N,N-dimethylaminoethoxyethanol, N,N-diethylaminoethoxyethanol, N-methyldiethanolamine, N-propyldiethanolamine, N-ethyldiethanolamine, t-butylethanolamine, t-butyldiethanolamine, 2-(2-aminoethoxy)ethanol, di-n-butylamine, tri-n-butylamine, di-iso-butylamine, ethyl-n-butylamine, pentylamine, 2-amino-2,3-dimethylbutane, 3-amino-2,2-dimethylbutane, 2-amino-1-methoxypropane, dipropylamine, monoamylamine, n-butylamine, isobutylamine, 3-amino-1-methoxypropane, and any combination thereof.
In at least one embodiment the control system can detect through the use of sensors the corrosion resulting from aqueous fluids or the formation of salt compounds. These sensors are pH, Chloride, Fe, Nitrogen, total nitrogen, ammonia, electrical resistance corrosion probes. In addition to measuring the corrosive environment these sensors provide input into the analyzer facilitating the calculation of appropriate amounts of chemical additives.
While this invention may be embodied in many different forms, there 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. All patents, patent applications, scientific papers, and any other referenced materials mentioned herein are incorporated by reference in their entirety. Furthermore, the invention encompasses any possible combination of some or all of the various embodiments described herein and/or incorporated herein. In addition the invention encompasses any possible combination that also specifically excludes any one or some of the various embodiments described herein and/or incorporated herein.
The above disclosure is intended to be illustrative and not exhaustive. This description will suggest many variations and alternatives to one of ordinary skill in this art. The compositions and methods disclosed herein may comprise, consist of, or consist essentially of the listed components, or steps. As used herein the term “comprising” means “including, but not limited to”. As used herein the term “consisting essentially of” refers to a composition or method that includes the disclosed components or steps, and any other components or steps that do not materially affect the novel and basic characteristics of the compositions or methods. For example, compositions that consist essentially of listed ingredients do not contain additional ingredients that would affect the properties of those compositions. Those familiar with the art may recognize other equivalents to the specific embodiments described herein which equivalents are also intended to be encompassed by the claims.
All ranges and parameters disclosed herein are understood to encompass any and all subranges subsumed therein, and every number between the endpoints. For example, a stated range of “1 to 10” should be considered to include any and all subranges between (and inclusive of) the minimum value of 1 and the maximum value of 10; that is, all subranges beginning with a minimum value of 1 or more, (e.g. 1 to 6.1), and ending with a maximum value of 10 or less, (e.g. 2.3 to 9.4, 3 to 8, 4 to 7), and finally to each number 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10 contained within the range.
All numeric values are herein assumed to be modified by the term “about,” whether or not explicitly indicated. The term “about” generally refers to a range of numbers that one of skill in the art would consider equivalent to the recited value (i.e., having the same function or result). In many instances, the term “about” may include numbers that are rounded to the nearest significant figure. Weight percent, percent by weight, % by weight, wt %, and the like are synonyms that refer to the concentration of a substance as the weight of that substance divided by the weight of the composition and multiplied by 100.
As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the content clearly dictates otherwise. Thus, for example, reference to a composition containing “a compound” includes a mixture of two or more compounds. As used in this specification and the appended claims, the term “or” is generally employed in its sense including “and/or” unless the content clearly dictates otherwise.
This completes the description of the preferred and alternate embodiments of the invention. Those skilled in the art may recognize other equivalents to the specific embodiment described herein which equivalents are intended to be encompassed by the claims attached hereto. | A method of correcting measurements of a chemical sensor used in an industrial facility. The method involves correcting for errors known to occur in the steady state and the dynamic state for specifically recognized situations. This method allows for correcting errors that occur due to deadtime, false zero measurements, and non-linear disturbances. The method combines automated measurement techniques and human know how to progressively learn and refine the accuracy of the corrections. | 2 |
BACKGROUND OF THE INVENTION
[0001] This invention relates generally to a railroad wheels, and more specifically to a method to repair worn railroad wheels to enable them to be returned to service.
[0002] During service, railroad wheels wear away, as they are designed to be sacrificial relative to the railroad tracks. Additionally, wheels can be removed for other defects such as spalling, shelling, and out-of-roundness.
[0003] When a wheel is removed from service for tread defects, it may be re-machined to adjust its profile relative to the rail geometry, provided that there is sufficient rim metal remaining. Presently, the most common reason that wheels are discarded is because of wearing to a minimum dimension.
[0004] Weld build-up or fusion welding of a new ring to the wheel hub is prohibitive because of tight quality standards imposed on rail wheels by the Association of American Railroads (AAR). Currently there are no good repair techniques for rail wheels due to restrictions on inclusions or cracks that would generally result from traditional welding techniques.
[0005] One non-welding approach taken to address the wear problem has been to shrink fit a new steel ring onto the wheel hub using thermal expansion techniques. However, a disadvantage to this approach is that the ring or “tire” is under tension in service, and as it wears thinner it becomes highly vulnerable to cracking.
[0006] Wheels are a high-cost item for rail operators. Accordingly it would be desirable to have a repair method for extending the service life of worn railroad wheels that also meets stringent safety requirements.
BRIEF DESCRIPTION OF THE INVENTION
[0007] The above-mentioned need or needs may be met by exemplary embodiments that provide methods for repairing rail wheels resulting in a metallurgical bond between faying surfaces.
[0008] An exemplary embodiment provides a method including disposing a ring member having an inner faying surface about a railroad wheel body having an outer faying surface to form a wheel assembly. The method includes metallurically bonding the ring member to the railroad wheel body at the inner and outer faying surfaces to provide an integral wheel structure.
[0009] Another exemplary embodiment provides a method including providing an inner faying surface on a ring member, providing an outer faying surface on a railroad wheel body, and shirk fitting the ring member to the railroad wheel body under suitable conditions so that the inner and outer faying surfaces are brought into intimate contact, and metallurically bonding the ring member to the wheel body under suitable bonding conditions to form an integral wheel structure.
[0010] Another exemplary embodiment provides an article including an integral wheel structure comprising an inner wheel body portion obtained from a worn railroad wheel and an outer portion circumferentially disposed about the inner wheel portion and being metallurically bonded thereto.
[0011] Another exemplary embodiment provides an assembly including an inner wheel body portion obtained from a worn railroad wheel and including an outer faying surface, a ring member disposed about the inner wheel body portion and including an inner faying surface, and an electroplated material disposed on at least one of the outer or inner faying surfaces.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the concluding part of the specification. The invention, however, may be best understood by reference to the following description taken in conjunction with the accompanying drawing figures in which:
[0013] FIG. 1 is a schematic representation of an exemplary railroad wheel.
[0014] FIG. 2 is a cross-sectional view of a worn railroad wheel exhibiting a defect.
[0015] FIG. 3 is a schematic representation showing an exploded view of an exemplary wheel assembly and a resulting integral wheel structure.
[0016] FIG. 4 is a flowchart of an exemplary wheel repair process.
DETAILED DESCRIPTION OF THE INVENTION
[0017] Referring to the drawings wherein identical reference numerals denote the same elements throughout the various views, FIG. 1 illustrates an exemplary railroad wheel 10 including a body 12 with a rim 14 extending about the circumference of the body. The body 12 has a hub 16 having a bore 18 therethrough for receiving an axle. In use, wheels are secured to opposing ends of an axle with the wheels spaced to rotatably contact parallel railroad tracks. A flange 20 extends radially outward from the rim for retaining the wheels on the railroad tracks. Railroad wheel 10 represents a wheel that has been used in service, and which exhibits wear or other defect(s).
[0018] As used herein, “wheel body” refers to that portion of railroad wheel 10 that is utilized in an exemplary repair process.
[0019] As used herein, “faying surface” means that surface of a member which is in contact with, or in close proximity to, another member to which it is to be joined.
[0020] As used herein, “diffusion bonding” refers to a solid-state welding process that produces coalescence of faying surfaces by application of pressure and elevated temperatures. The process does not involve melting of the relative parts.
[0021] As used herein, “shrink fitting” refers to a technique in which pieces of a structure are heated or cooled, employing the phenomenon of thermal expansion, to make a non-metallurgical joint.
[0022] As used herein, “induction heating” refers to a process of heating a metal object by electromagnetic induction.
[0023] As used herein, “quenching” refers to a quick cooling technique in which metal is rapidly cooled from high temperatures, usually in oil or water, in order to provide the formation of desirable phases and increase the hardness level of the steel.
[0024] As used herein, “tempering” refers to a process whereby quenched steel is reheated to a temperature below the eutectoid temperature, then cooled in a controlled fashion in order to increase ductility and toughness and to ensure dimensional stability.
[0025] As used herein, “metallurgically clean” means a surface free of stable oxides which is thus suitable for forming metallurgical bonds by processes such as electroplating or diffusion bonding.
[0026] All percentages provided herein are percent by weight, unless otherwise noted.
[0027] The worn wheel 10 may exhibit defects such as thin tread, spalling, out of roundness, high flange, or any other defect that may be corrected using the processes described herein. However, solely for exemplary purposes and not by way of limitation, FIG. 2 depicts a worn wheel 10 as having a thin rim 14 . For reference, a profile 26 of an unworn wheel rim is illustrated in phantom.
[0028] As illustrated, the worn wheel 10 does not provide sufficient material at the rim to allow a re-profiling operation. A worn wheel in such condition would therefore be condemned. Exemplary methods disclosed herein provide means for enabling restoration of a condemnable wheel for a return to service.
[0029] As shown in FIG. 3 , in an exemplary embodiment, the worn wheel is machined at the tread and flange regions a sufficient amount to remove the defect and to provide a wheel body 12 having a substantially cylindrical outer faying surface 28 .
[0030] In an exemplary embodiment, a ring member 30 is utilized with the wheel body 12 to provide additional structural material at the circumference of the wheel body. In an exemplary embodiment, the ring member 30 is machined to provide an inner faying surface 32 adapted for a close fit with outer faying surface 28 .
[0031] In an exemplary embodiment, one or both of the faying surfaces 28 , 32 are plated with an electroplated material 34 . The electroplated material 34 may be useful to deter oxidation of the faying surface(s). The faying surfaces 28 , 32 may also be cleaned, brushed, or otherwise prepared for bonding.
[0032] In an exemplary embodiment, ring member 30 is disposed about the wheel body 12 to form a wheel assembly 36 . In general terms, wheel assembly 36 undergoes subsequent treatment in order to form a metallurgical diffusion bond between ring member 30 and wheel body 12 , and the integral wheel structure is further processed prior to returning to service.
[0033] An exemplary ring member 30 is formed of steel having a composition compatible with the steel of wheel body 12 . It is contemplated that wheel body 12 may have been from a forged- or cast- steel wheel. An exemplary ring member 30 may be provided with a flange 38 to approximate a final wheel profile as will be explained in greater detail below. Some exemplary steel compositions are those compositions for wheels mandated by the AAR, and listed in AAR M- 107 / 208 . For example, a Class ‘C’ wheel would have 0.67-0.77% C, 0.60-0.90% Mn, 0.030% max P, 0.005-0.040% S, and 0.15-1.00% Si.
[0034] It is contemplated within the scope of this disclosure that the rim build up may be provided by a ring member having a different composition than the wheel body. The composition of the ring member may be selected to provide improved wear resistance. Some exemplary alloys able to provide improved wear resistance as compared to the wear resistance of the wheel body are suggested in U.S. Pat. No. 6,073,346. Suggested alloys include high speed tool steels, such as AISI M4 steel (composition of 1.3% C, 0.30% Mn, 0.30% Si, 4.00% Cr, 4.00% V, 5.50% W and 4.50% Mo), AISI T15 steel, 300 series stainless steel or nickel alloy matrix steels, PH series stainless steels, ferretic stainless steels, crucible CPM 9 V, 10 V and 15 V vanadium carbide containing tool steels, D2 type chromium carbide containing tool steels, and CARPENTER AERMET 100. Thus, the wear and traction properties of the tread and flange could be optimized without reducing the strength and life of the wheel body.
[0035] With reference to FIG. 4 , an exemplary process 40 includes: providing a ring member 30 (Step 42 ); providing a worn wheel 10 (Step 44 ); machining the ring member 30 to provide inner faying surface 32 (Step 46 ); and machining the worn wheel 10 to provide wheel body 12 and outer faying surface 28 (Step 48 ). The faying surfaces 28 , 32 are prepared for bonding (Step 50 ).
[0036] During machining of the worn wheel 10 , sufficient material is removed from about the wheel circumference to remove the flange and at least a portion of the rim and provide an outer diameter of wheel body 12 . Machining step 48 removes oxidation and other surface impurities. The machining step is utilized to address defects such as insufficient rim depth, worn flange profile, out of roundness, and others as will be appreciated by those of skill in the art.
[0037] The ring member 24 is machined to the extent necessary to provide an inner diameter able to mate with the outer diameter of wheel body 12 . The ring member must be able to provide sufficient material to be joined to wheel body at the rim and flange regions.
[0038] In an exemplary process, metallurgically clean faying surfaces could be prepared for bonding by electroplating one or both surfaces 28 , 32 . In an exemplary embodiment, the faying surfaces 28 , 32 can be plated to prevent surface oxidation, and to provide a diffusion couple and active interface for bonding. In an exemplary embodiment, an inexpensive metal, such as nickel or chromium may be used, or a diffusion couple could be created by plating one faying surface with nickel, and the other faying surface with copper. Alternately, a noble metal such as gold, platinum or palladium can be utilized. The plating can be carried out using brush plating (also known as selective plating) or by immersion plating. The plating could be a thin flash coat about 0.5 micron thick aimed at keeping the surfaces clean, or a heavier deposit of 1-5 microns aimed at producing better mobility of the faying surfaces and increasing the diffusion rate earlier in the heating cycle. Other plating and surface preparation techniques may be employed by those having skill in the art.
[0039] In an exemplary embodiment, the inner faying surface 32 of ring member 30 is brought into close physical contact with the outer faying surface 28 of the wheel body 12 in a shrink-fitting operation (Step 52 ) to form the wheel assembly 36 . An exemplary shrink-fitting operation includes induction heating of the ring member as is known in the art. In an exemplary embodiment, the shrink-fitting operation occurs in an argon atmosphere.
[0040] In an exemplary embodiment, wheel assembly 36 is heated to a predetermined temperature for sufficient time so that diffusion bonding occurs between the faying surfaces 28 , 32 (Step 54 ). In an exemplary embodiment, the tension of the ring member 30 against the wheel body 12 from the shrink fit operation provides sufficient pressure for the diffusion bonding to occur. In other exemplary methods, the wheel assembly 30 may be subjected to additional pressurizing means.
[0041] In an exemplary embodiment, during the diffusion bonding step, the wheel assembly 36 is heated to a normalizing temperature in an argon atmosphere or in air so that a desired microstructure grows across the boundary between the wheel body 12 and ring member 30 . In an exemplary embodiment, the wheel assembly 30 is heated to about 2050° F. (about 1121° C.) for about 4 hours to provide sufficient diffusion bonding. It is anticipated that other bonding conditions would provide suitable grain growth across the boundary. In an exemplary embodiment, the bonding temperatures range from about 1650° F. to about 2300° F. (about 899° C.-1260° C.), for sufficient time at temperature to bond the ring member 30 to the wheel body 12 . For example, the time at temperature may be from about 1 to about 6 hours, although extended bonding time may be desired.
[0042] As illustrated in FIG. 3 , as the diffusion bonding takes place, the ring member 30 and wheel body 12 become an integral wheel structure 56 and the tension from the shrink-fit is stress-relieved out of the part.
[0043] Referring again to FIG. 4 , in an exemplary embodiment, following the diffusion bonding step, the integral wheel structure 56 is subjected to one or more processes before being returned to service. For example, the integral wheel structure 56 may be subjected to rim quenching (Step 58 ), tempering (Step 60 ), inspection (Step 62 ) and finishing (Step 64 ) before returning to service (Step 68 ).
[0044] In an exemplary embodiment, the rim quenching step includes spraying the outer tread area of the wheel assembly with water while the wheel is rotated. The rim-quenching step promotes desirable microstructure for hardening the steel, and introduces a residual compressive stress in the tread area which greatly improves the tread's fatigue strength.
[0045] In an exemplary embodiment, the tempering step includes reheating the rim-quenched wheel to approximately 800-900° F. (426-482° C.) for approximately one hour to improve the toughness of the tread area, and to yield a Brinnell hardness in the ranges required by AAR M107/208 (i.e.: HBN of 321-363 for a Class C wheel).
[0046] In an exemplary embodiment, the inspection step includes a hardness check, an ultrasonic inspection for internal defects, and a dimensional check, all for conformance to the AAR specification.
[0047] In an exemplary embodiment, the finishing step may include machining the integral wheel structure 56 to provide a radial flange with an acceptable profile. If the ring member 30 included a flange 38 , the finishing step may include shaping the flange and the flange/rim interface. If ring member 30 was not flanged prior to bonding, then the finishing step may include providing a radial flange by removing sufficient material from a circumferential surface of the integral wheel structure 56 and shaping the flange and flange/rim interface. As a final processing step, the wheel may be shot peened to 8C intensity in accordance with AAR M107/208, and then marked with the appropriate legends.
[0048] Thus, exemplary embodiments disclosed herein provide methods for repairing and restoring worn railroad wheels. The exemplary methods utilize diffusion bonding techniques to provide a restored wheel able to meet structural and safety requirements including applicable AAR standards while avoiding disallowed techniques such as fusing welding.
[0049] This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to make and use the invention. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims. | A method includes shrink fitting a ring member about a railroad wheel body and metallurically bonding the ring member to the railroad wheel body. A wheel assembly includes an inner portion obtained from a worn railroad wheel, a ring member disposed about the inner portion, and suitable electroplating material disposed on at least one of the faying surfaces. The wheel assembly may be heated under suitable conditions to provide diffusion bonding across interfacing faying surfaces to produce an integral wheel structure. Appropriate quenching, tempering, and finishing processes may be utilized to obtain desired properties. An article formed thereby includes an inner body portion obtained from a worn railroad wheel and a metallurically bonded outer circumferential portion. The outer portion may comprise a composition selected for desired wear characteristics. | 8 |
This application is the U.S. national phase of International Application No. PCT/EP2011/064623 filed 25 Aug. 2011 which designated the U.S. and claims priority to EP 10174083.5 filed 26 Aug. 2010, the entire contents of each of which are hereby incorporated by reference.
BACKGROUND AND SUMMARY
As is known, (all-rac)-α-tocopherol (or as it has mostly been denoted in the prior art, “d,l-α-tocopherol”) is a mixture of four diastereomeric pairs of enantiomers of 2,5,7,8-tetra-methyl-2-(4′,8′,12′-trimethyl-tridecyl)-6-chromanol (α-tocopherol), which is the biologically most active and industrially most important member of the vitamin E group.
Many processes for the manufacture of “d,l-α-tocopherol” (referred to as such in the literature reviewed hereinafter) by the reaction of 2,3,5-trimethyl-hydro-p-benzoquinone (TMHQ) with isophytol or phytol in the presence of a catalyst or catalyst system and in a solvent or solvent system are described in literature.
One raw material for the production of 2,3,6-trimethylphenol (“2,3,6-TMP”, starting material for TMHQ) is m-cresol. Due to limited availability and an increasing demand for m-cresol, prices for m-cresol and 2,3,6-TMP are growing. Therefore a m-cresol-independent access to TMHQ is strongly desired.
One option for a m-cresol free access to TMHQ could be a reaction sequence starting from 2,6-dimethyl-p-benzoquinone (“2,6-DMQ”).
The hydrogenation of 2,6-DMQ to 2,6-dimethyl-hydro-p-benzoquinone (“2,6-DMHQ”) is a literature-known reaction. There are procedures, using stoichiometric reducing agents such as sodium dithionite [Na 2 (S 2 O 4 )] in different solvents (see Carpino, Louis A.; Triolo, Salvatore A.; Berglund, Richard A.; J. Org. Chem. 1989, 54(14), 3303-3310; He, Li; Zhu, Chenjiang; He, Xiaopeng; Tang, Yanhui; Chen, Guorong; Zhongguo Yiyao Gongye Zazhi 2006, 37(5), 301-302; and CN 1 699 356 A).
Modern syntheses describe catalytic hydrogenations using hydrogen in presence of a heterogeneous catalyst [e.g. Pd-catalyst, methanol, room temperature] as claimed in AU 2004 201 149 A1.
The closest state of the art for a reaction sequence from DMQ to TMHQ (see FIG. 1 ) is disclosed in JP 2006-249 036.
In this reaction sequence each of the three reaction steps is carried out in a different solvent: For the hydrogenation of 2,6-DMQ to 2,6-DMHQ alcohols (iso-propanol), alkyl esters (butyl acetate) or ethers (diethyl ether) are claimed as solvents. The aminomethylation of 2,6-DMHQ is carried out in aromatic hydrocarbons, such as toluene, benzene, ethylbenzene or xylene. And the final de-amination is described in lower aliphatic alcohols (methanol, iso-propanol), alkyl esters (butyl acetate) or ethers (tetrahydrofuran, dioxane). This procedure requires not only the use of various solvents but also the technical operations for two to three solvent changes (distillation).
To by-pass the disadvantage of solvent changes and to achieve high selectivity and yield, it was investigated to carry out as many steps as possible of the reaction sequence from 2,6-DMQ to TMHQ in the same solvent. It was further investigated to find solvents especially suitable for such reaction steps. MTBE (methyl tert.-butyl ether), methoxycyclopentane, ethyl tert.-butyl ether (ETBE) and tert.-amyl methyl ether were found as being especially suitable for the purpose of the present invention. MTBE, ETBE and methoxycyclopentane have the further advantage from an economical point of view that they are cheap. ETBE e.g. is used as antiknock agent for biodiesel. MTBE has the further advantage that it would simplify the work-up because it does not form peroxides.
Disadvantages of the processes known from the prior art are also that larger amounts of bis-Mannich adducts such as e.g. 3,5-dimethyl-2,6-bismorpholinomethyl-hydro-p-benzoquinone are formed as by-products. These by-products have to be removed before TMHQ can be further reacted with isophytol and/or phytol and/or derivatives of isophytol or phytol to vitamin E, because the further reaction products are much more difficult to remove than the bis-Mannich adducts themselves. Advantageously these bis-Mannich adducts are formed in a much lower amount when using the solvents according to the present invention.
Thus, the present invention is directed to a process for the manufacture of 2,3,5-tri-methyl-hydro-p-benzoquinone comprising the following steps:
a) hydrogenating 2,6-dimethyl-p-benzoquinone with hydrogen in the presence of a hydrogenation catalyst in an organic solvent to obtain 2,6-dimethyl-hydro-p-benzoquinone; b) reacting 2,6-dimethyl-hydro-p-benzoquinone with a secondary amine and formaldehyde in an organic solvent to obtain 2,6-dimethyl-3-(N,N-disubstituted aminomethyl)-hydro-p-benzoquinone; c) reacting 2,6-dimethyl-3-(N,N-disubstituted aminomethyl)-hydro-p-benzoquinone with hydrogen in the presence of a hydrogenolysis catalyst in an organic solvent to obtain 2,3,5-trimethyl-hydro-p-benzoquinone; wherein the organic solvent in all steps a), b) and c) is independently selected from the group consisting of methyl tert.-butyl ether, ethyl tert.-butyl ether, methyl tert.-amyl ether, methoxycyclopentane and any mixtures thereof.
Preferably the organic solvent in all steps a), b) and c) is the same. More preferably this organic solvent is methyl tert.-butyl ether.
Since the obtained 2,3,5-trimethyl-hydro-p-benzoquinone can be further reacted with isophytol and/or phytol and/or derivatives of isophytol or phytol vitamin E, the present invention is also directed to
a process for the manufacture of vitamin E comprising at least one of the steps a) to c) according to the process of the present invention to obtain 2,3,5-trimethyl-hydro-p-benzoquinone which is further reacted with isophytol and/or phytol and/or derivatives of isophytol or phytol vitamin E according to processes known to the person skilled in the art.
Since 2,3,5-trimethyl-hydro-p-benzoquinone may first be converted to 2,3,5-trimethyl-hydro-p-benzoquinone acetate before this 2,3,5-trimethyl-hydro-p-benzoquinone acetate is reacted with isophytol and/or phytol and/or derivatives of isophytol or phytol to vitamin E acetate according to processes known to the person skilled in the art, the present invention is furthermore also directed to
a process for the manufacture of vitamin E acetate comprising at least one of the steps a) to c) according to the process of the present invention to obtain 2,3,5-trimethyl-hydro-p-benzoquinone, which is then converted to 2,3,5-trimethyl-hydro-p-benzoquinone acetate, which is further reacted with isophytol and/or phytol and/or derivatives of isophytol or phytol to vitamin E.
Since the single steps have not been described using these solvents before, the present invention is also directed to
a process for the manufacture of 2,6-dimethyl-hydro-p-benzoquinone comprising the step of hydrogenating 2,6-dimethyl-p-benzoquinone with hydrogen in the presence of a hydrogenation catalyst in an organic solvent, wherein the organic solvent is selected from the group consisting of methyl tert.-butyl ether, ethyl tert.-butyl ether, methyl tert.-amyl ether, methoxycyclopentane and any mixtures thereof; a process for the manufacture of 2,6-dimethyl-3-(N,N-disubstituted aminomethyl)-hydro-p-benzoquinone (preferably of 2,6-dimethyl-3-morpholinomethyl-hydro-p-benzoquinone) comprising the step of reacting 2,6-dimethyl-hydro-p-benzoquinone with a secondary amine (preferably with morpholine) and formaldehyde in an organic solvent to obtain 2,6-dimethyl-3-(N,N-disubstituted aminomethyl)-hydro-p-benzoquinone (preferably 2,6-dimethyl-3-morpholinomethyl-hydro-p-benzoquinone), wherein the organic solvent is selected from the group consisting of methyl tert.-butyl ether, ethyl tert.-butyl ether, methyl tert.-amyl ether, methoxycyclopentane and any mixtures thereof; a process for the manufacture of 2,3,5-trimethyl-hydro-p-benzoquinone comprising the step of reacting 2,6-dimethyl-3-(N,N-disubstituted aminomethyl)-hydro-p-benzoquinone (preferably 2,6-dimethyl-3-morpholinomethyl-hydro-p-benzoquinone) with hydrogen in the presence of a hydrogenolysis catalyst in an organic solvent to obtain 2,3,5-trimethyl-hydro-p-benzoquinone, wherein the organic solvent is selected from the group consisting of methyl tert.-butyl ether, ethyl tert.-butyl ether, methyl tert.-amyl ether, methoxycyclopentane and any mixtures thereof;
as well as to processes, where two of the three steps are carried out in these solvents, i.e. to
a process for the manufacture of 2,6-dimethyl-3-(N,N-disubstituted aminomethyl)-hydro-p-benzoquinone (preferably 2,6-dimethyl-3-morpholinomethyl-hydro-p-benzoquinone) comprising the following steps:
hydrogenating 2,6-dimethyl-p-benzoquinone with hydrogen in the presence of a hydrogenation catalyst in an organic solvent to obtain 2,6-dimethyl-hydro-p-benzoquinone; reacting 2,6-dimethyl-hydro-p-benzoquinone with a secondary amine (preferably with morpholine) and formaldehyde in an organic solvent to obtain 2,6-dimethyl-3-(N,N-disubstituted aminomethyl)-hydro-p-benzoquinone (preferably 2,6-dimethyl-3-morpholinomethyl-hydro-p-benzoquinone); wherein the organic solvent is independently selected from the group consisting of methyl tert.-butyl ether, ethyl tert.-butyl ether, methyl tert.-amyl ether, methoxycyclopentane and any mixtures thereof;
a process for the manufacture of 2,3,5-trimethyl-hydro-p-benzoquinone comprising the following steps:
i) reacting 2,6-dimethyl-hydro-p-benzoquinone with a secondary amine (preferably with morpholine) and formaldehyde in an organic solvent to obtain 2,6-dimethyl-3-(N,N-disubstituted aminomethyl)-hydro-p-benzoquinone (preferably 2,6-dimethyl-3-morpholinomethyl-hydro-p-benzoquinone); ii) reacting 2,6-dimethyl-3-(N,N-disubstituted aminomethyl)-hydro-p-benzoquinone (preferably 2,6-dimethyl-3-morpholinomethyl-hydro-p-benzoquinone) with hydrogen in the presence of a hydrogenolysis catalyst in an organic solvent to obtain 2,3,5-trimethyl-hydro-p-benzoquinone, wherein the organic solvent used in steps i) and ii) is independently selected from the group consisting of methyl tert.-butyl ether, ethyl tert.-butyl ether, methyl tert.-amyl ether, methoxycyclopentane and any mixtures thereof;
a process for the manufacture of 2,3,5-trimethyl-hydro-p-benzoquinone comprising the following steps:
a) hydrogenating 2,6-dimethyl-p-benzoquinone with hydrogen in the presence of a hydrogenation catalyst in an organic solvent to obtain 2,6-dimethyl-hydro-p-benzoquinone; b) reacting 2,6-dimethyl-hydro-p-benzoquinone with a secondary amine (preferably with morpholine) and formaldehyde in an organic solvent to obtain 2,6-dimethyl-3-(N,N-disubstituted aminomethyl)-hydro-p-benzoquinone (preferably 2,6-dimethyl-3-morpholinomethyl-hydro-p-benzoquinone); c) reacting 2,6-dimethyl-3-(N,N-disubstituted aminomethyl)-hydro-p-benzoquinone (preferably 2,6-dimethyl-3-morpholinomethyl-hydro-p-benzoquinone) with hydrogen in the presence of a hydrogenolysis catalyst in an organic solvent to obtain 2,3,5-trimethyl-hydro-p-benzoquinone; wherein the organic solvent in steps a) and c) is independently selected from the group consisting of methyl tert.-butyl ether, ethyl tert.-butyl ether, methyl tert.-amyl ether, methoxycyclopentane and any mixtures thereof.
Also here preferably the organic solvent is the same in two steps. More preferably this organic solvent is methyl tert.-butyl ether.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a prior art reaction sequence to obtain TMHQ from DMQ;
FIG. 2 show the chemical formulas for compounds of the Examples; and
FIG. 3 show the chemical formulas for Mannich adducts of dimethyl amine, diethyl amine, di-n-propyl amine, diethanol amine, piperidine, 1-methyl-piperazine, and pyrrolidine.
DETAILED DESCRIPTION
The single steps are now described in more detail below.
Main advantage of the present invention is that all steps a) to c) may be performed in the same solvent, so that a solvent change is not necessary. It is even not necessary to separate the product of step a) and step b) from the solvent used; it can, however, be optionally done.
In step b) the excess of the Mannich reagents can be separated off and reused. This is important for recycling on a larger scale and is done during work-up. For the work-up, one possibility is an aqueous work-up, the second one is a distillation, as described in U.S. Pat. No. 6,066,731, whose content is included herein by reference; see especially column 5, line 8 ff. and example 6 of U.S. Pat. No. 6,066,731. The distillation of the components off the Mannich reagent (i.e. secondary amine+formaldehyde) is then preferably coupled to the distillation of the solvent.
Step a) Hydrogenation of 2,6-dimethyl-p-benzoquinone (DMQ) to 2,6-dimethyl-hydro-p-benzoquinone (DMHQ)
The Pd-catalyzed hydrogenation of 2,6-DMQ can surprisingly successfully be carried out in excellent yield in MTBE (methyl tert.-butyl ether), methoxycyclopentane, ethyl tert.-butyl ether (ETBE), tert.-amyl methyl ether and any mixtures thereof, more preferably in MTBE and ETBE and any mixtures thereof.
The amount of solvent used, as well as the purity of the starting material (=DMQ) is not critical. It may even be possible to work in a slurry containing the starting material (=2,6-DMQ), the solvent and the catalyst. Preferably 1 l of solvent is used per 1 to 5 mol of 2,6-DMQ.
Supported noble-metal catalysts from the group of platinum metals are efficient catalysts for the hydrogenation of 2,6-DMQ to 2,6-DMHQ. Preferably the noble metal is Pd or Pt. The catalyst can be supported on carbon or an oxide such as silica and alumina or any mixture thereof, preferably on alumina.
The metal loading can be 1-10 weight-%, preferably 3-6 weight-% on the carrier. The substrate/catalyst ratio (s/c) can be in the range of 20-5'000, preferably 40-1'000.
Noble-metal catalysts supported on carbon have preferably a BET surface area in the range of 800 to 1500 m 2 /g, more preferably they have a BET surface area in the range of 900-1200 m 2 /g. Most preferably 50% of the particles of these noble-metal catalysts supported on carbon also have a size ≦20-50 μm (i.e. the so-called particle size D50≦20-50 μm).
The catalysts supported on an oxide such as silica and alumina or any mixture thereof have preferably a BET surface area in the range of 50 to 500 m 2 /g, more preferably they have a BET surface area in the range of 80 to 300 m 2 /g, most preferably are egg-shell catalysts with these BET surface areas.
An “egg-shell” catalyst in the context of the present invention is a catalyst where the catalytically active metal (Pd, Pt etc.) has a non-uniform distribution on the support and is located mainly on the shell of such catalyst.
The hydrogenation of 2,6-DMQ can be carried out at 1-120 bara, preferably at 2-15 bara. The reaction proceeds faster (<1 hour) under a hydrogen pressure of 3 or 6 bara but it can also be performed at atmospheric pressure, however, with longer reaction times; e.g. with reaction times of 16 to 20 hours with 5% Pd/C (s/c 100) at 23 or 40° C.
Good mixing of the reaction system is crucial for by-passing mass transport limitation.
The reaction can be carried out at a temperature in the range of 0 to 150° C., preferably at a temperature in the range of 10 to 90° C., especially preferred are temperatures in the range of 20 to 70° C.
Step b) Manufacture of the Mannich Adduct of 2,6-dimethyl-hydro-p-benzoquinone
Preferably step b) is carried out in the same solvent as step a).
The following solvents are used: MTBE (methyl tert.-butyl ether), methoxycyclopentane, ethyl tert.-butyl ether (ETBE), tert.-amyl methyl ether and any mixtures thereof, preferably MTBE and tert.-amyl methyl ether and any mixtures thereof.
The amount of solvent preferably used is 1 l per 1-5 mol of 2,6-DMHQ, more preferably 1 l per 1-10 mol of 2,6-DMHQ.
Suitable secondary amines are N,N-disubstituted amines L-N(H)-L 1 , where L and L 1 are independently from each other aliphatic linear alkyl groups which may optionally contain heteroatoms such as O and N, aliphatic branched alkyl groups which may optionally contain heteroatoms such as O and N, aryl groups which may optionally contain heteroatoms such as O and N, or L and L 1 may form an aliphatic N-containing cycloalkane which may optionally contain further heteroatoms such as O and N.
Examples of secondary amines, where L and L 1 are independently from each other aliphatic linear alkyl groups which may optionally contain heteroatoms such as O and N, are
secondary amines, where L and L 1 are independently from each other aliphatic linear C 1-10 alkyl groups (preferably C 1-6 alkyl groups); secondary amines, where L and L 1 are independently from each other aliphatic linear C 1-10 alkyl groups (preferably C 1-6 alkyl groups) which contain one or more hydroxy groups (preferably they contain one hydroxy group); these hydroxy groups may be tertiary, secondary or primary hydroxy groups; secondary amines, where L is an aliphatic linear C 1-10 alkyl group (preferably a C 1-6 alkyl group), and L 1 is an aliphatic linear C 1-10 alkyl group (preferably a C 1-6 alkyl group) which contains one or more hydroxy groups (preferably it contains one hydroxy group); or vice versa; these hydroxy groups may be tertiary, secondary or primary hydroxy groups; secondary amines, where L and L 1 are independently from each other aliphatic linear C 1-10 alkyl groups (preferably C 1-6 alkyl groups) which contain one or more amino groups (preferably they contain one amino group); these amino groups may be tertiary, secondary or primary amino groups; secondary amines, where L is an aliphatic linear C 1-10 alkyl group (preferably a C 1-6 alkyl group), and L 1 is an aliphatic linear C 1-10 alkyl group (preferably a C 1-6 alkyl group) which contains one or more amino groups (preferably it contains one amino group); or vice versa; these amino groups may be tertiary, secondary or primary amino groups; secondary amines, where L is an aliphatic linear C 1-10 alkyl group (preferably a C 1-6 alkyl group) which contains one or more hydroxy groups (preferably it contains one hydroxy group), and L 1 is an aliphatic linear C 1-10 alkyl group (preferably a C 1-6 alkyl group) which contains one or more amino groups (preferably it contains one amino group); or vice versa; these amino groups may be tertiary, secondary or primary amino groups; secondary amines, where L and L 1 are independently from each other aliphatic linear C 1-10 alkyl groups (preferably C 1-6 alkyl groups) which contain one or more (preferably one) amino and one or more (preferably one) hydroxy groups; these amino and hydroxy groups may be independently from each other tertiary, secondary or primary; as partially illustrated in schemes 1, 2 and 3 below:
Preferred examples of such secondary amines are dimethyl amine, diethyl amine, diethanol amine and di-n-propyl amine.
Examples of secondary amines, where L and L 1 are independently from each other aliphatic branched alkyl groups which may optionally contain heteroatoms such as O and N, are
secondary amines, where L and L 1 are independently from each other aliphatic branched C 3-10 alkyl groups (preferably C 3-6 alkyl groups); secondary amines, where L and L 1 are independently from each other aliphatic branched C 3-10 alkyl groups (preferably C 3-6 alkyl groups) which contain one or more hydroxy groups (preferably they contain one hydroxy group); these hydroxy groups may be tertiary, secondary or primary hydroxy groups; secondary amines, where L is an aliphatic branched C 3-10 alkyl group (preferably a C 3-6 alkyl group), and L 1 is an aliphatic branched C 3-10 alkyl group (preferably a C 3-6 alkyl group) which contains one or more hydroxy groups (preferably it contains one hydroxy group); or vice versa; these hydroxy groups may be tertiary, secondary or primary hydroxy groups; secondary amines, where L and L 1 are independently from each other aliphatic branched C 3-10 alkyl groups (preferably C 3-6 alkyl groups) which contain one or more amino groups (preferably they contain one amino group); these amino groups may be tertiary, secondary or primary amino groups; secondary amines, where L is an aliphatic branched C 3-10 alkyl group (preferably a C 3-6 alkyl group), and L 1 is an aliphatic branched C 3-10 alkyl group (preferably a C 3-6 alkyl group) which contains one or more amino groups (preferably it contains one amino group); or vice versa; these amino groups may be tertiary, secondary or primary amino groups; secondary amines, where L is an aliphatic branched C 3-10 alkyl group (preferably a C 3-6 alkyl group) which contains one or more hydroxy groups (preferably it contains one hydroxy group), and L 1 is an aliphatic branched C 3-10 alkyl group (preferably a C 3-6 alkyl group) which contains one or more amino groups (preferably it contains one amino group); or vice versa; these hydroxy and amino groups may be tertiary, secondary or primary amino groups; secondary amines, where L and L 1 are independently from each other aliphatic branched C 3-10 alkyl groups (preferably C 3-6 alkyl groups) which contain one or more (preferably one) amino and one or more (preferably one) hydroxy groups; these amino and hydroxy groups may be independently from each other tertiary, secondary or primary.
The formulae of these secondary amines are analogous to the ones illustrated in schemes 1 to 3 above.
A preferred example of such secondary amines is di-iso-propyl amine.
Examples of secondary amines, where L and L 1 may form an aliphatic N-containing cycloalkane which may optionally contain further heteroatoms such as O and N, are piperidine, 1-methyl-piperazine, pyrrolidine and morpholine.
The term “secondary amines” encompasses also N,N-disubstituted amines L-N(H)-L 1 , where L and L 1 are independently from each other single or multiple unsaturated linear alk(mono-/oligo-/poly)enyl groups which may optionally contain heteroatoms such as O and N, single or multiple unsaturated branched alk(mono-/oligo-/poly)enyl groups which may optionally contain heteroatoms such as O and N, or L and L 1 may form an aromatic N-containing heterocycle which may optionally contain further heteroatoms such as O and N.
Examples of secondary amines, where L and L 1 are independently from each other single or multiple unsaturated linear alk(mono-/oligo-/poly)enyl groups which may optionally contain heteroatoms such as O and N, are
secondary amines, where L and L 1 are independently from each other single or multiple unsaturated linear C 2-10 alk(mono-/oligo-/poly)enyl groups (preferably C 3-6 alk(mono-/oligo-/poly)enyl groups); secondary amines, where L and L 1 are independently from each other single or multiple unsaturated linear C 2-10 alk(mono-/oligo-/poly)enyl groups (preferably C 3-6 alk(mono-/oligo-/poly)enyl groups) which contain hydroxy groups; these hydroxy groups may be primary, secondary or tertiary hydroxy groups; secondary amines, where L and L 1 are independently from each other single or multiple unsaturated linear C 2-10 alk(mono-/oligo-/poly)enyl groups (preferably C 3-6 alk(mono-/oligo-/poly)enyl groups) which contain amino groups; these amino groups may be primary, secondary or tertiary amino groups; secondary amines, where L and L 1 are independently from each other single or multiple unsaturated linear C 2-10 alk(mono-/oligo-/poly)enyl groups (preferably C 3-6 alk(mono-/oligo-/poly)enyl groups) which contain amino and hydroxy groups; these amino and hydroxy groups may be independently from each other primary, secondary or tertiary.
The formulae of these secondary amines are analogous to the ones illustrated in schemes 1 to 3 above.
Examples of secondary amines, where L and L 1 are independently from each other single or multiple unsaturated branched alk(mono-/oligo-/poly)enyl groups which may optionally contain heteroatoms such as O and N, are
secondary amines, where L and L 1 are independently from each other single or multiple branched linear C 3-10 alk(mono-/oligo-/poly)enyl groups (preferably C 3-6 alk(mono-/oligo-/poly)enyl groups); secondary amines, where L and L 1 are independently from each other single or multiple branched linear C 3-10 alk(mono-/oligo-/poly)enyl groups (preferably C 3-6 alk(mono-/oligo-/poly)enyl groups) which contain hydroxy groups; these hydroxy groups may be primary, secondary or tertiary hydroxy groups; secondary amines, where L and L 1 are independently from each other single or multiple unsaturated branched C 3-10 alk(mono-/oligo-/poly)enyl groups (preferably C 3-6 alk(mono-/oligo-/poly)enyl groups) which contain amino groups; these amino groups may be primary, secondary or tertiary amino groups; secondary amines, where L and L 1 are independently from each other single or multiple unsaturated branched C 3-10 alk(mono-/oligo-/poly)enyl groups (preferably C 3-6 alk(mono-/oligo-/poly)enyl groups) which contain amino and hydroxy groups; these amino and hydroxy groups may be independently from each other primary, secondary or tertiary.
The formulae of these secondary amines are analogous to the ones as illustrated in schemes 1 to 3 above.
Examples of secondary amines, where L and L 1 may form an aromatic N-containing heterocycle which may optionally contain further heteroatoms such as O and N, are pyridine, pyrrol and imidazol.
Examples of secondary amines, where L is an aliphatic linear C 1-10 alkyl group or a branched C 3-10 alkyl group and L 1 is an aryl group which may optionally contain heteroatoms such as O and N, are e.g. N-methyl N-phenyl amine, N-ethyl N-phenyl amine, N-methyl N-pyridyl amine etc.
Preferably the following secondary amines are used (see FIG. 3 ): dimethyl amine, diethyl amine, di-n-propyl amine, diethanol amine, piperidine, 1-methyl-piperazine, pyrrolidine and morpholine. More preferably morpholine and piperidine are used. Most preferred is morpholine
Equivalents of Mannich reagent: 1.0 to 1.5 mol equivalents; a broader range is 0.8 to 2.0 equivalents per 1 mol of 2,6-DMHQ.
The formaldehyde used in step b) may be used in form of gaseous formaldehyde, formalin (=aqueous 37 weight-% formaldehyde solution), trioxane and para-formaldehyde, preferably it is used in form of formalin, i.e. an aqueous 37 weight-% solution. The aqueous formaldehyde solution may also be more concentrated or more diluted than 37 weight-%, its concentration may e.g be in the range of 10 to 50 weight-%, 25-50 weight-%, 35 to 55 weight-% or 35 to 40 weight-%.
The formaldehyde/formalin/para-formaldehyde is preferably used in an amount of 0.7 to 1.2 mol based on 1 mol of the secondary amine, more preferably in an amount of 0.9 to 1.1 mol based on 1 mol of the secondary amine, most preferably in an equimolar amount based on the amount of the secondary amine.
Preferably this step is carried out at a temperature in the range of 20 to 80° C., more preferably at a temperature in the range of 23 to 60° C.
The reaction can be carried out under pressure (N 2 atmosphere), but this is usually not necessary since the reaction also proceeds smoothly at atmospheric pressure.
Usually the reaction proceeds in a time in the range of 2 to 48 hours, preferably in the range of 6 to 24 hours.
For more details about this reaction step see U.S. Pat. No. 6,066,731 which content is included herein by reference, especially columns 2 and 3, as well as examples 1-3 and 8. The Mannich reagent can also be pre-formed.
Step c) Hydrogenolysis of 2,6-dimethyl-3-(N,N-disubstituted aminomethyl)-hydro-p-benzoquinone to 2,3,5-trimethyl-hydro-p-benzoquinone
Preferably step c) is carried out in the same solvent as step b). More preferably step c) is carried out in the same solvent as step a) and step b).
The following solvents are used: MTBE (methyl tert.-butyl ether), methoxycyclopentane, ethyl tert.-butyl ether (ETBE), tert.-amyl methyl ether and any mixtures thereof, preferably MTBE and tert.-amyl methyl ether and any mixtures thereof.
Usually 1 l of solvent is used per 0.2 to 10 mol of starting material (=disubstituted 2,6-dimethyl-3-(N,N-disubstituted aminomethyl-hydro-p-benzoquinone, preferably 2,6-dimethyl-3-morpholinomethyl-hydro-p-benzoquinone); preferably 1 l of solvent is used per 0.3 to 5 mol of starting material (=disubstituted 2,6-dimethyl-3-(N,N-disubstituted aminomethyl-hydro-p-benzoquinone, preferably 2,6-dimethyl-3-morpholinomethyl-hydro-p-benzoquinone).
Reaction Temperature
The range from 120° C. to 200° C. is preparatively useful, a more specific useful temperature range is 140-180° C.; the most preferred temperature range is 150 to 170° C.
The hydrogen pressure is typically in the range of 5 to 100 bara, preferably in the range of 15 to 55 bara.
The reaction usually proceeds in a time in the range of 2 to 10 hours; preferably the reaction is complete in a time in the range of from 4 to 6 hours.
Supported noble-metal catalysts from the group of platinum metals, as well as nickel are efficient catalysts for this hydrogenolysis. The catalyst can be supported on carbon or an oxide such as silica and alumina or any mixture thereof, as well as on porous glass such as TRISOPERL®.
The catalyst used in step c) is preferably selected from the group consisting of Pd/C, Pd/SiO 2 , Pd/Al 2 O 3 , Pd/TP (TP=TRISOPERL®) and Ra—Ni (=Ni-alloy). More preferred catalysts are Pd/C, Pd/TP and Pd/SiO 2 . Most preferred catalysts are Pd/C and Pd/TP.
Noble-metal catalysts (especially Pd) supported on carbon have preferably a BET surface area in the range of 800 to 1500 m 2 /g, more preferably they have a BET surface area in the range of 900-1200 m 2 /g. Most preferably 50% of the particles of these noble-metal catalysts supported on carbon also have a size ≦20-50 μm (i.e. the so-called particle size D50≦20-50 μm).
The catalysts supported on an oxide such as silica and alumina or any mixture thereof have preferably a BET surface area in the range of 50 to 500 m 2 /g, more preferably they have a BET surface area in the range of 80 to 300 m 2 /g. Most preferably are eggshell catalysts.
Preferably the weight ratio of the nobel metal (Pd, Ni) contained in these catalysts to the starting material of this step (=2,6-dimethyl-3-(N,N-disubstituted aminomethyl)-hydro-p-benzoquinone with the preferences as given above) is 1:(20-10000), preferably 1:(50-1000), more preferably around 1:200.
The invention is now further illustrated by the following non-limiting examples.
EXAMPLES
The following abbreviations were used (see also FIG. 2 ):
MTBE=tert.-butyl methyl ether
rpm=revolutions per minute
wt-%=weight-%
DM-2-MHQ=dimethyl-2-morpholinomethyl-quinone
(2,6-)DMQ=2,6-dimethylbenzoquinone (starting material for step a), its purity being not critical)
(2,6-)DMHQ=2,6-dimethyl-hydro-p-benzoquinone
3,5-DM-2-MQ=3,5-dimethyl-2-morpholinomethyl-quinone
3,5-DM-2-MHQ=3,5-dimethyl-2-morpholinomethyl-hydro-p-benzoquinone (=2,6-dimethyl-3-morpholinomethyl-hydro-p-benzoquinone)
3,5-DM-2,6-BMHQ=3,5-dimethyl-2,6-bismorpholinomethyl-hydro-p-benzoquinone
3,5-DM-2,6-BMQ=3,5-dimethyl-2,6-bismorpholinomethyl-p-benzoquinone
TMHQ=2,3,5-trimethyl-hydro-p-benzoquinone
TMQ=2,3,6-trimethylbenzoquinone
TetraMHQ=2,3,5,6-tetramethylhydro-p-benzoquinone
s/c=substrate/catalyst ratio
bara=bar absolute
Catalysts:
The following catalysts were used:
a 5% Pd/C catalyst with a BET surface area of 1000 m 2 /g and the following particle size distribution: 10% of the particles ≦6 μm, 50% of the particles ≦28 μm, and 90% of the particles ≦79 μm, as e.g. commercially available from Evonik under the tradename “Pd/C (5%) E 101 N/D (Evonik)” (“catalyst A”); a 10% Pd/C catalyst with a a BET surface area of 1000 m 2 /g and a pore volume of 1.1 ml/g, as e.g. commercially available from Evonik under the tradename “Pd/C (10%) E 101 N/D (Evonik)” (“catalyst B”); a 10% Pd/C egg-shell catalyst as e.g. commercially available from Evonik under the tradename “Pd/C (10%): E 101 NN/D (Evonik)” (“catalyst C”); a 5% Pd/SiO 2 catalyst with a BET surface area of 275 m 2 /g, a pore volume of 1.7 ml/g, a volume of mesopores of 0.66 ml/g and a volume of macropores of 1.04 ml/g as e.g. commercially available from Evonik under the tradename “Pd/SiO 2 (5%) E EXP/D (Evonik)” (“catalyst D”); a 5% Pd/CaCO 3 egg-shell catalyst with a BET surface area of 8 m 2 /g, a bulk density of 0.37 kg/l, and whereby 50% of the particles have a size ≦5 μm as e.g. commercially available from Evonik under the tradename “5% Pd/CaCO 3 E 407 R/D” (“catalyst E”); a 5% Pd/Al 2 O 3 egg-shell catalyst with a BET surface area of 93 m 2 /g and a pore volume of 0.3 ml/g as e.g. commercially available from Evonik under the tradename “5% Pd/Al 2 O 3 E 213 R/D” (“catalyst F”); a 5% Pt/C catalyst with a BET surface area of 100 m 2 /g, a volume of the micropores of 0.35 ml/g, a volume of the mesopores of 0.35 ml/g, a volume of the macropores of 0.30 ml/g and a pore volume 1.0 ml/g as e.g. commercially available from Evonik under the tradename “5% Pt/C F 101 R/D” (“catalyst G”); a Raney-Nickel catalyst containing Ni in an amount in the range of 90 to 95 weight-%, based on the total weight of the catalyst, aluminum in an amount in the range of 5.5 to 8 weight-%, based on the total weight of the catalyst, iron in an amount in the range ≦0.4 weight-%, based on the total weight of the catalyst, and the following particle size distribution: 10% of the particles ≦5 to 13 μm, 50% of the particles ≦35 to 70 μm, and 90% of the particles ≦300 μm as e.g. commercially available under the tradename “RaNi MC700 B.2063” (“catalyst H”); a 1% Pd/TP catalyst (“catalyst I”) whose manufacture is described below.
1% Pd/TP was Manufactured as Follows:
21 mg Pd(OAc) 2 (0.09 mmol) were suspended in 50 mL of dichloromethane. 1 g of TRISOPERL® were added and the solvent was removed (bath temperature: 40° C./pressure: 950 mbara). The carrier doped with Pd(OAc) 2 was calcinated for 2 hours at 300° C. in an oven (pre-heating of the oven for 20 minutes for 1000 W to 300° C.). The loading of the catalyst on the carrier was then ca. 1 weight-% Pd, i.e. 10 mg of Pd on 1 g of carrier. TRISOPERL® by the Schuller GmbH, Wertheim/Germany, is a porous Silica glass with an average particle size in the range of 100 to 200 μm, an average pore size of 54.47 nm, a specific surface of 93.72 m 2 /g and an average pore volume of 1255.5 mm 3 /g.
Solvents:
Acetonitrile, tert.-amyl methyl ether, tert.-butyl ethyl ether, ethyl acetate, methanol, methoxycyclopentane, tert.-butyl methyl ether, iso-propanol and toluene are all commercially available and were used as such.
2,6-Dimethylhydroquinone, diethanolamine, di-n-propylamine, pyrrolidine, 1-methyl-piperazine, piperidine, morpholine, dimethylamine solution (aq. 40%), and formaldehyde solution (aq. 37%) are commercially available and were used without further purification.
I) Hydrogenation of 2,6-dimethyl-p-benzoquinone (DMQ) to 2,6-dimethyl-hydro-p-benzoquinone (DMHQ)
For the hydrogenation of 2,6-DMQ to 2,6-DMHQ different solvents were tested, with variation of the catalyst (support), hydrogen pressure and temperature. After the reaction, the products were isolated and the purity and yield of DMHQ, based on DMQ, were determined by GC and quantitative 1 H-NMR.
The results and the reaction conditions and parameters are summarized in the following tables. Some of the experiments are described in more detail below.
TABLE 1
Hydrogenation of DMQ using various solvents (temperature: 40° C.,
hydrogen pressure: 6 bara, catalyst: 10% Pd/C, s/c: 100).
Selectivity
[based on
Example
time [h]
Solvent
GC-area %]
Yield [%]
I.1
1.5
MTBE
94.8
88
I.2
1.5
methoxycyclopentane
93.1
85
I.3
3.5
tert.-butyl ethyl ether
96.3
88
I.4
2
tert.-amyl methyl ether
95.2
87
Detailed Description of Example I.3
In a 13 ml glass flask flushed with argon (3×6 bara), 275 mg (2.0 mmol) of DMQ were dissolved in 1.63 g (2.2 ml) of tert.-butyl ethyl ether. To the solution 20.0 mg (s/c 100) of Pd/C (10 weight-% Pd, based on the total weight of the catalyst) catalyst were added. The autoclave was flushed with hydrogen and heated to 40° C. with magnetic stirring (500 rpm). When the reaction temperature was reached, the autoclave was pressurized with 6 bara hydrogen and stirring was increased to 1'000 rpm. After 3.5 hours reaction time, the suspension was cooled to 23° C. and the hydrogen pressure was released. The suspension was filtered and the catalyst was washed with 1 ml of MTBE. The combined organic layers were concentrated at 40° C. under reduced pressure. The product was obtained in 88% yield and 91% purity.
TABLE 2
Hydrogenation of DMQ at various hydrogen pressures
(temperature: 40° C., solvent: MTBE, catalyst: 10% Pd/C: s/c: 100).
Selectivity [based on
Example
H 2 [bara]
time [h]
GC-area %]
Yield [%]
I.5
6
1
96.9
94
I.6
3
1
95.7
94
I.7
1
20
96.2
92
Investigation of the hydrogen pressure showed that at 6 bara the Pd-catalyzed hydrogenation of 2,6-DMQ is complete with ca. 97% selectivity within 1 hour reaction time at 40° C. A similar result is obtained at 3 bara hydrogen pressure. When carried out at atmospheric pressure, the reaction proceeds slower but 99.6% conversion is achieved after 20 hours with 96.2% selectivity (Table 2).
Detailed Description of Example I.5
In a 30 ml steel autoclave flushed with argon (3×6 bara), 154.2 mg (1.1 mmol) of DMQ were dissolved in 0.82 g (1.1 ml) of MTBE. To the solution 12.4 mg (s/c 100) of Pd/C (10 weight-% Pd, based on the total weight of the catalyst) catalyst were added. The autoclave was flushed with hydrogen and heated to 40° C. with magnetic stirring (500 rpm). When the reaction temperature was reached, the autoclave was pressurized with 6 bara hydrogen and stirring was increased to 1'000 rpm. After 1 hour reaction time, stirring was reduced to 100 rpm, the suspension was cooled to 23° C. and the hydrogen pressure was released. The suspension was filtered via syringe filter (0.45 μm), the catalyst was washed with 5 ml of MTBE and the combined organic layers were concentrated at 40° C. under reduced pressure. The product was obtained in 94% yield and 87% purity.
Detailed Description of Example I.7
In a 50 ml round-bottom flask, 4.6 g (29.8 mmol) of DMQ were dissolved in 33 ml of MTBE under argon atmosphere. To the solution were added 318 mg (s/c 100) of Pd/C (10 weight-% Pd, based on the total weight of the catalyst) catalyst and the argon atmosphere was exchanged with hydrogen (three cycles). After that the reaction mixture was stirred (800 rpm) for 16 hours at 40° C. under hydrogen atmosphere (balloon). The black suspension was filtered and the catalyst washed with 10 ml of MTBE. The organic layer was concentrated at 40° C. under reduced pressure and the solid product was dried for one hour at 40° C. at 15 mbara. The product was obtained in 92% yield and 90% purity.
TABLE 3
Hydrogenation of DMQ at various temperatures (solvent: MTBE)
Temper-
Selectivity
Catalyst
H 2
ature
time
[based on
Yield
Example
[s/c]
[bara]
[° C.]
[h]
GC-area %]
[%]
I.8
Pd/C (5%)
6
40
0.5
96.9
87
[40]
I.9
Pd/C (5%)
6
23
0.5
98.2
81
[40]
I.10
Pd/C (10%)
1
40
20
96.2
92
[100]
I.11
Pd/C (10%)
1
23
16
99.5
76
[100]
I.12
Pd/C (10%)
11
60
16
95.7
69
[100]
Compared to the hydrogen pressure, the reaction temperature plays a minor role (Table 3).
TABLE 4
Hydrogenation of DMQ using Pd-catalysts on various supports
(temperature: 40° C., hydrogen pressure: 6 bara, solvent: MTBE).
Selectivity
[based
Example
Catalyst [s/c]
time [h]
on GC-area %]
Yield [%]
I.13
Pd/C (5%) [40]
0.5
96.9
87
I.14
Pd/C (10%) [100]
0.5
96.5
95
I.15
Pd/SiO 2 (5%) [100]
1.0
97.0
95
I.16
Pd/Al 2 O 3 (5%) [100]
1.0
98.2
97
With Pd/Al 2 O 3 slightly higher yield and selectivity is observed than with Pd/SiO 2 or Pd/C (Table 4).
Example I.17
In a 2-liter steel autoclave, 125.7 g (815 mmol) of DMQ were dissolved in 910 ml of tert.-butyl methyl ether (MTBE) under a nitrogen atmosphere at 23° C. To this solution were added 8.64 g (s/c 100) of a Pd/C (10 weight-% Pd, based on the total weight of the catalyst) catalyst. With stirring (gas dispersion stirrer, 1000 rpm) the autoclave was pressurized with hydrogen to 6 bara. During this process the temperature rose to 30° C. After the exothermic reaction had ceased, the reaction mixture was heated to 40° C. After 75 min, the catalyst was filtered off and washed with 140 ml of MTBE. The combined ether layers were concentrated under reduced pressure at 40° C. and the solid crude product was dried for 2 hours at 40° C. The off-white crystalline DMHQ was obtained in 92% yield and 85% purity.
Most reactions were carried out on a 150-300 mg scale. Experiment I.17 demonstrates that the reaction conditions from the screening experiments also apply for a larger laboratory scale (125 g). In this case, the hydrogenation was performed in a 2 liter steel autoclave. To ensure good hydrogen transfer into the solution a gas entrainment stirrer was used. With this set-up the product was obtained in good yield of 92% and 95.6% selectivity.
II) Manufacture of the Mannich Adduct of 2,6-dimethyl-hydro-p-benzoquinone
Example II.1
Aminomethylation in tert.-butyl methyl ether
To a stirred suspension of DMHQ (20.8 g, 99.5 wt-%, 150.0 mmol) in tert.-butyl methyl ether (MTBE, 75 ml) was added under an argon atmosphere the Mannich reagent (26.35 g, 225.0 mmol, 1.5 mol equiv.) prepared from morpholine and paraformaldehyde according to example 1 of U.S. Pat. No. 6,066,731. The resulting brown solution was heated to 60° C. (oil bath temperature 70° C.) for 6 hours. During this time the brown solution turned to a suspension. The reaction mixture was cooled down to 0° C. in an ice bath, the colourless crystals filtered off by suction filtration (P3 frit), washed twice with 10 ml each of cold (0° C.) MTBE, and dried overnight (16 hours) at room temperature under high vacuum. The colourless crystals obtained (31.704 g) were analyzed by quantitative HPLC. The mother liquor was evaporated in vacuo (40° C., 20 mbara), further dried overnight (16 hours) at room temperature under high vacuum. The 11.369 g dark red oil was analyzed by quantitative HPLC.
Yield according to quantitative HPLC (crystals+mother liquor): 91.3% 3,5-DM-2-MHQ, 1.0% 2,6-DMHQ, 0.5% 3,5-DM-2-MQ, 0.0% 2,6-DMQ, 0.0% 3,5-DM-2,6-BMHQ, 0.2% 3,5-DM-2,6-BMQ.
Example II.2
Aminomethylation in tert.-butyl ethyl ether
Carrying out the experiment described in Example II.1 with tert.-butyl ethyl ether as the solvent, the following results were obtained:
Yield according to quantitative HPLC (crystals+mother liquor): 85.1% 3,5-DM-2-MHQ, 0.7% 2,6-DMHQ, 0.4% 3,5-DM-2-MQ, 0.0% 2,6-DMQ, 0.0% 3,5-DM-2,6-BMHQ, 0.7% 3,5-DM-2,6-BMQ.
Example II.3
Aminomethylation in tert.-amyl methyl ether
Carrying out the experiment described in Example II.1 with tert.-amyl methyl ether as the solvent, the following results were obtained:
Yield according to quantitative HPLC (crystals+mother liquor): 89.5% 3,5-DM-2-MHQ, 0.7% 2,6-DMHQ, 1.9% 3,5-DM-2-MQ, 0.0% 2,6-DMQ, 0.0% 3,5-DM-2,6-BMHQ, 1.0% 3,5-DM-2,6-BMQ.
Example II.4
Aminomethylation in methoxycyclopentane
Carrying out the experiment described in Example II.1 with methoxycyclopentane as the solvent, the following results were obtained:
Yield according to quantitative HPLC (crystals+mother liquor): 84.4% 3,5-DM-2-MHQ, 0.6% 2,6-DMHQ, 1.6% 3,5-DM-2-MQ, 0.0% 2,6-DMQ, 0.0% 3,5-DM-2,6-BMHQ, 1.2% 3,5-DM-2,6-BMQ.
Comparison Example II.C1
Aminomethylation in Toluene
To a stirred suspension of 2,6-dimethyl-hydro-p-benzoquinone (0.697 g, 99.1 wt %, 5.0 mmol) in toluene (2.5 ml) was added under an argon atmosphere morpholine (0.528 g, 6.0 mmol, 1.2 mol equiv.). After stirring for 10 minutes a paraformaldehyde solution (37% in H 2 O, 0.487 g, 6.0 mmol, 1.2 mol equiv. formaldehyde) was added in one portion, and the temperature rose from 23 to 30° C. The resulting brown two-phase mixture was then heated at 55° C. (oil bath temperature 70° C.) for 16 hours. After cooling down to 30° C., 10 ml of H 2 O and 30 ml of ethyl acetate were added. After phase separation the aqueous layer was extracted with 20 ml of ethyl acetate, and the combined organic extracts dried over sodium sulfate. After filtration and evaporation in vacuo (40° C./20 mbara) and further drying (2 h, high vacuum, room temperature), the resulting 1.136 g red-brown solid was analyzed by quantitative HPLC.
Yield: 70.3% 3,5-DM-2-MHQ, 1.2% 2,6-DMHQ, 4.9% 3,5-DM-2-MQ, 0.1% 2,6-DMQ, 3.1% 3,5-DM-2,6-BMHQ, 0.7% 3,5-DM-2,6-BMQ.
Analytical Data for the Morpholine Mannich Adduct
1 H-NMR (300 MHz, d 6 -DMSO): δ=6.35 (s, 1H, CH), 3.55 (t, 4H, J=4.52 Hz, CH 2 O), 3.53 (s, 2H, Ar—CH 2 N), 2.40 (br t, 4H, J=4.52 Hz, CH 2 CH 2 N), 2.11 (s, 3H, CH 3 ), 2.08 (s, 3H, CH 3 ).
13 C-NMR (75 MHz, d 6 -DMSO): δ=149.7 (COH), 145.2 (COH), 125.1 (CCH 3 ), 124.7 (CCH 3 ), 118.2 (CCH 2 ), 114.3 (CH), 66.2 (CH 2 O), 55.2 (Ar—CH 2 N), 52.6 (CH 2 CH 2 N), 16.8 (CH 3 ), 12.3 (CH 3 ).
LC-MS (ES) m/z: 238 [M+H + ], 151 [M+H + -morpholine].
IR (ATR, cm −1 ): 3348 (m, —OH), 3011 (w, Ar—H), 2956, 2933, (m, —CH 3 , —CH 2 —CH 3 , —CH 2 —), 2848 (m, —NR 3 ), 1470 (m), 1230 (s), 1009 (s).
In an analogous manner the Mannich adducts with piperidine, 1-methyl-piperazine, pyrrolidine, diethanolamine, di-n-propylamine, diethylamine or dimethylamine were synthesized which analytical data are given below.
Analytical Data for the Piperidine Mannich Adduct
1 H-NMR (300 MHz, d 6 -DMSO): δ=6.30 (s, 1H, CH), 3.54 (s, 2H, Ar—CH 2 N), 2.40 (br, 2H, CH 2 CH 2 N), 2.07 (s, 6H, CH 3 ), 1.50 (br quin, 4H, CH 2 CH 2 N), 1.42 (br t, 2H, CH 2 CH 2 CH 2 N).
13 C-NMR (75 MHz, d 6 -DMSO): δ=150.4 (COH), 145.0 (COH), 124.5 (CCH 3 ), 124.2 (CCH 3 ), 118.0 (CCH 2 ), 114.4 (CH), 56.7 (Ar—CH 2 N), 53.2 (CH 2 CH 2 N), 25.5 (CH 2 CH 2 N), 23.7 (CH 2 CH 2 CH 2 N), 16.8 (CH 3 ), 12.2 (CH 3 ).
LC-MS (ES) m/z: 236 [M+H + ], 151 [M+H + -piperidine].
IR (ATR, cm −1 ): 3348 (m, —OH), 3011 (w, Ar—H), 2956, 2933, (m, —CH 3 , —CH 2 —CH 3 , —CH 2 —), 2848 (m, —NR 3 ), 1470 (m), 1230 (s), 1009 (s).
Analytical Data for the 1-methyl-piperazine Mannich Adduct
1 H-NMR (300 MHz, d 6 -DMSO): δ=6.32 (s, 1H, CH), 3.55 (s, 2H, Ar—CH 2 N), 2.47-2.22 (br, 8H, NCH 2 CH 2 N), 2.15 (s, 3H, CH 3 ), 2.08 (s, 3H, CH 3 ), 2.07 (s, 3H, CH 3 N).
13 C-NMR (75 MHz, d 6 -DMSO): δ=150.0 (COH), 145.1 (COH), 124.6 (CCH 3 ), 124.6 (CCH 3 ), 118.1 (CCH 2 ), 114.4 (CH), 55.4 (Ar—CH 2 N), 54.7 (NCH 2 CH 2 N), 51.9 (NCH 2 CH 2 N), 45.6 (NCH 3 ), 16.8 (CH 3 ), 12.3 (CH 3 ).
LC-MS (ES) m/z: 251 [M+H + ], 151 [M+H + -1-methyl-piperazine].
Analytical Data for the Pyrrolidine Mannich Adduct
1 H-NMR (300 MHz, d 6 -DMSO): δ=6.30 (s, 1H, CH), 3.72 (s, 2H, Ar—CH 2 N), 2.53 (m, 4H, CH 2 CH 2 N), 2.09 (s, 3H, CH 3 ), 2.07 (s, 3H, CH 3 ), 1.72 (m, 4H, CH 2 CH 2 N).
13 C-NMR (75 MHz, d 6 -DMSO): δ=150.3 (COH), 144.9 (COH), 124.4 (CCH 3 ), 123.9 (CCH 3 ), 119.0 (CCH 2 ), 114.3 (CH), 53.3 (Ar—CH 2 N), 53.0 (CH 2 CH 2 N), 23.2 (CH 2 CH 2 N), 16.8 (CH 3 ), 12.2 (CH 3 ).
LC-MS (ES) m/z: 222 [M+H + ], 151 [M+H + -pyrrolidine].
Analytical Data for the Diethanolamine Mannich Adduct
13 C-NMR (75 MHz, d 6 -DMSO): δ=150.5 (COH), 145.0 (COH), 124.5 (CCH 3 ), 124.3 (CCH 3 ), 119.1 (CCH 2 ), 114.5 (CH), 58.4 (HOCH 2 CH 2 N or HOCH 2 CH 2 N), 55.7 (HOCH 2 CH 2 N or HOCH 2 CH 2 N), 53.1 (Ar—CH 2 N), 16.8 (CH 3 ), 12.3 (CH 3 ).
LC-MS (ES) m/z: 256 [M+H + ], 151 [M+H + -diethanolamine].
GC-MS (EI) (silylated) m/z: 528 [M + +4 TMS−CH 3 ], 440 [M + +3 TMS−2 CH 3 ] 295 [M + +2 TMS-diethanolamine].
Analytical Data for the Di-n-Propylamine Mannich Adduct
1 H-NMR (300 MHz, d 6 -DMSO): δ=6.29 (s, 1H, CH), 3.63 (s, 2H, Ar—CH 2 N), 2.38 (t, J=7.54 Hz, 4H, CH 3 CH 2 CH 2 N), 2.07 (s, 3H, CH 3 ), 1.45 (m, J=7.35 Hz, J=7.54 Hz, 4H, CH 3 CH 2 CH 2 N), 0.81 (t, J=7.35 Hz, 4H, CH 3 CH 2 CH 2 N).
13 C-NMR (75 MHz, d 6 -DMSO): δ=150.6 (COH), 144.9 (COH), 124.4 (CCH 3 ), 124.1 (CCH 3 ), 118.5 (CCH 2 ), 114.4 (CH), 54.9 (CH 2 CH 2 CH 2 N), 53.1 (Ar—CH 2 N), 19.1 (CH 2 CH 2 CH 2 N), 16.8 (CH 3 ), 12.1 (CH 3 ), 11.7 (CH 2 CH 2 CH 2 N).
GC-MS (EI) (silylated) m/z: 395 [M + +2 TMS], 380 [M + +2 TMS−CH 3 ] 295 [M + +2 TMS−di-n-propylamine].
Analytical Data for the Dimethylamine Mannich Adduct
1 H-NMR (300 MHz, d 6 -DMSO): δ=6.32 (s, 1H, CH), 3.49 (s, 2H, Ar—CH 2 N), 2.19 (2, 6H, NCH 3 ), 2.08 (s, 3H, CH 3 ), 2.07 (s, 3H, CH 3 ).
GC-MS (ES) m/z: 195 [M + ], 150 [M + +-dimethylamine], 122, 107, 46 [H 2 NMe 2 + ].
III) Hydrogenolysis of 2,6-dimethyl-3-morpholinomethyl-hydro-p-benzoquinone to 2,3,5-trimethyl-hydro-p-benzoquinone
Example III.1
Hydrogenolysis of 2,6-dimethyl-3-morpholinomethyl-hydro-p-benzoquinone in tert.-butyl methyl ether
A) In a 100-ml steel autoclave 3,5-dimethyl-2-morpholinomethyl-hydro-p-benzoquinone (3,5-DM-2-MHQ, 3.256 g, 91.1 wt %, 12.5 mmol) and a Pd/C (10%) catalyst (0.266 g, s/c 50) were suspended in 30 ml of methyl-tert.-butyl ether (MTBE) under a nitrogen atmosphere. After flushing with nitrogen three times, the autoclave was pressurized with hydrogen to 6 bara, then the pressure was released, and the mixture heated up to 160° C. during 30 minutes while stirring (gas dispersion stirrer, 1000 rpm). When the reaction temperature was reached, the autoclave was pressurized with 22 bara H 2 . After 5 h, the catalyst was filtered off under exclusion of air by using a 0.45 μm membrane filter and washed with 6.5 ml of MTBE. The combined dark yellow ether layers were washed twice with aqueous 1 N HCl solution (40 ml) and once with H 2 O (40 ml, resulting pH=2). The aqueous washings were re-extracted with MTBE (40 ml). The combined organic extracts were dried over Na 2 SO 4 , concentrated under reduced pressure (20 mbara) at 40° C. and further dried for 1 hour at room temperature to give 1.703 g off-white crystals which were analyzed by HPLC.
Yield according to quantitative HPLC: 82.3% TMHQ, 0.0% 3,5-DM-2-MHQ, 0.1% TMQ, 2.9% 2,6-DMHQ, 1.2% TetraMHQ.
B) To a 30-ml—steel autoclave 2,6-dimethyl-3-morpholinomethyl-hydro-p-benzoquinone (300 mg, 99%), methyl tert.-butyl ether (3 ml) and Pd/C (30 mg, 5% palladium) were added. The closed autoclave was agitated at 140° C. for 7 hours. The hydrogen pressure was initially set on 6 bara. For analysis purposes a small sample is silylated. According to GC-area % the yield of 2,3,5-trimethyl-hydro-p-benzoquinone is 93.5% (97.3% conversion), based on 2,6-dimethyl-hydro-p-benzoquinone.
Example III.2
Hydrogenolysis of 2,6-dimethyl-3-morpholinomethyl-hydro-p-benzoquinone in tert.-butyl ethyl ether
Carrying out the experiment described in Example III.1 with tert.-butyl ethyl ether as the solvent (at 29 bara H 2 , reaction time 4 h) in a 125-ml autoclave, the following results were obtained:
Yield: 67.0% TMHQ, 0.0% 3,5-DM-2-MHQ, 0.1% TMQ, 1.9% 2,6-DMHQ, 0.1% TetraMHQ.
Example III.3
Hydrogenolysis of 2,6-dimethyl-3-morpholinomethyl-hydro-p-benzoquinone in tert.-amyl methyl ether
Carrying out the experiment described in Example III.1 with tert.-amyl methyl ether as the solvent (at 27 bara H 2 , reaction time 4 h; no additional solvent used for washing the catalyst after filtration) in a 125-ml autoclave, the following results were obtained:
Yield: 80.1% TMHQ, 0.0% 3,5-DM-2-MHQ, 0.5% TMQ, 1.7% 2,6-DMHQ, 0.5% TetraMHQ.
Example III.4
Hydrogenolysis of 2,6-dimethyl-3-morpholinomethyl-hydro-p-benzoquinone in methoxycyclopentane
Carrying out the experiment described in Example III.1 with methoxycyclopentane as the solvent (at 24 bara H 2 , reaction time 4 h; no additional solvent used for washing the catalyst after filtration) in a 125-ml autoclave, the following results were obtained:
Yield: 82.5% TMHQ, 0.0% 3,5-DM-2-MHQ, 0.1% TMQ, 1.5% 2,6-DMHQ, 0.1% TetraMHQ.
Example III.5-III.14
Hydrogenolysis of 2,6-dimethyl-3-morpholinomethyl-hydro-p-benzoquinone in tert.-butyl methyl ether with different catalysts
In a steel autoclave were methyl tert.-butyl ether, 2,6-dimethyl-3-morpholinomethyl-hydro-p-benzoquinone (10 weight % in methyl tert.-butyl ether) and catalyst (10-50 weight % based on 2,6-dimethyl-3-morpholinomethyl-hydro-p-benzoquinone) added. The closed autoclave was agitated (250 rpm) at 120-160° C. for 7 hours. The hydrogen pressure was initially set on 6-11 bara. For analysis a small probe was silylated. In the table below the results are summarized (based on GC-area %=“A %”).
TABLE 5
Hydrogenolysis of 3,5-DM-2-MHQ to TMHQ
Catalyst
H 2 Pressure
Temperature
Yield
Conversion
Selectivity
Example
[type]
s/c
[bara]
[° C.]
[A %]
[A %]
[A %]
III.5
5% Pd/C
90
6
140
93
97
96
III.6
5% Pd/C
90
6
160
91
100
91
III.7
5% Pd/C
90
11
140
94
99
95
III.8
10% Pd/C -
90
6
140
88
92
96
egg-shell
catalyst
III.9
5% Pd/SiO 2
90
6
140
66
69
96
III.10
5% Pd/SiO 2
90
11
140
71
74
95
III.11
1% Pd/TP
673
11
160
92
99
92
III.12
1% Pd/TP
90
11
140
90
98
92
III.13
5% Pd/CaCO 3
45
6
140
59
59
99
III.14
Ni alloy
1.2
11
140
58
60
98 | The present invention is directed to a process for the manufacture of 2,3,5-trimethyl-hydro-p-benzoquinone comprising the following steps: a) hydrogenating 2,6-dimethyl-p-benzoquinone with hydrogen in the presence of a hydrogenation catalyst in an organic solvent to obtain 2,6-dimethyl-hydro-p-benzoquinone; b) reacting 2,6-dimethyl-hydro-p-benzoquinone with a secondary amine and formal-dehyde in an organic solvent to obtain 2,6-dimethyl-3-(N,N-disubstituted aminomethyl)-hydro-p-benzoquinone; c) reacting 2,6-dimethyl-3-(N,N-disubstituted aminomethyl)-hydro-p-benzoquinone with hydrogen in the presence of a hydrogenolysis catalyst in an organic solvent to obtain 2,3,5-trimethylhydro-p-benzoquinone; wherein the organic solvent in all steps a), b) and c) is independently selected from the group consisting of methyl tert.-butyl ether, ethyl tert.-butyl ether, methyl tert.-amyl ether, methoxycyclopentane and any mixtures thereof. Preferably the organic solvent used in all steps a), b) and c) is the same. | 2 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of co-pending application Ser. No. 09/389,711, filed Sep. 3, 1999, and is also a continuation-in-part of copending application Ser. No. 10/038,207 filed Jan. 4, 2002, said application Ser. No. 10/038,207 being a continuation-in-part of copending application Ser. No. 09/921,979, filed Aug. 3, 2001, which claims priority of provisional application No. 60/293,613, filed May 25, 2001, said application Ser. No. 09/921,979 also being a continuation-in-part of application Ser. No. 09/493,628, filed Jan. 28, 2000, said application Ser. No. 09/493,628 being a continuation-in-part of application Ser. No. 09/327,243, filed Jun. 7, 1999, now U.S. Pat. No. 6,239,046, and application Ser. No. 09/327,244, also filed Jun. 7, 1999, now abandoned in favor of copending continuation application Ser. No. 09/956,639, filed Sep. 19, 2001; said application Ser. No. 09/921,979 also being a continuation-in-part of application Ser. No. 09/327,245 filed Jun. 7, 1999, now abandoned in favor of application Ser. No. 09/956,640 filed Sep. 19, 2001; said application Ser. No. 10/038,207 also being a continuation-in-part of said application Ser. No. 09/956,639, filed Sep. 19, 2001, which is a continuation of said application Ser. No. 09/327,244, filed Jun. 7, 1999, now abandoned; said application Ser. No. 10/038,207 also being a continuation-in-part of said copending application Ser. No. 09/956,640, filed Sep. 19, 2001, which is a continuation of said application Ser. No. 09/327,245, filed Jun. 7, 1999, now abandoned. All of these applications are fully incorporated by reference herein and made a part of this disclosure.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to multi-denier mixed textile fabrics for use in inflatable vehicle occupant restraint systems. More particularly, the invention relates to textile fabrics woven with fibers and yarns of different materials and denier sizes in either or both of the warp and fill directions and laminated with a film having adhesive and sealing properties useful in the manufacture of air bags and side curtains with improved physical characteristics.
[0004] 2. Description of the Related Art
[0005] Current restraint systems for automotive vehicles include driver and passenger side air bags that are instantaneously gas-inflated by means such as by explosion of a pyrotechnic material at the time of a collision to provide a protective barrier between vehicle occupants and the vehicle structure. Much of the impact of a collision is absorbed by the air bag, thus preventing or lessening the possibility of serious bodily injury to occupants of the vehicle. Such air bags are located, typically, in a collapsed, folded condition housed in the steering wheel, to protect the driver, and in the dashboard, to protect a passenger seated next to the driver. Recently, the automotive industry also has introduced air bags that are stored in the back of the front seats or in the rear seats to protect the cabin occupants in the event of a collision occurring on either side of the vehicle.
[0006] More recently still, a further safety feature that is made available for passenger vehicles, especially the so-called sport utility vehicles or SUVs, are side-impact protective inflatable side curtains designed to provide a cushioning effect in the event of side collisions or rollover accidents. These side curtains are stored in the roof of the vehicle and, in the event of a collision, deploy along the interior side walls of the SUV's cabin.
[0007] Each of these various types of air bags has different design and physical property requirements, such as gas (air) holding permeability, air pressure and volume, puncture resistance and adhesion of the coating material to a woven substrate. For example, driver side air bags must have little or no permeability and, as a result, are often made from a material having very little or no permeability. Passenger side air bags, on the other hand, require a controlled permeability, and are most often made from materials having some degree of permeability. Furthermore, all such vehicle air restraint devices must have superior packageability and anti-blocking qualities. Packageability refers to the ability for a relatively large device to be packaged in a relatively small space. Anti-blocking refers to the ability of the device to deploy almost instantaneously without any resistance caused by the material sticking to itself.
[0008] The air holding capability of side curtains is critical since they must remain inflated for an extended period of time to protect passengers in multiple rollovers. Unlike air bags which are designed to inflate instantaneously, and to deflate almost immediately after inflation in order to avoid injury to the driver and front seat passenger, air curtains used in SUVs, or in ordinary passenger vehicles, must be capable of remaining inflated in the range of from about three (3) to about twelve (12) seconds, depending upon the size of the curtain and the type of vehicle. An average passenger vehicle would require a side curtain of from about 60 inches to about 120 inches in length as measured along the length of the vehicle, and a larger vehicle, such as a minivan, would require an even longer side curtain. The maximum inflation period of a side curtain should be sufficient to protect the cabin occupants during three (3) rollovers, the maximum usually experienced in such incidents.
[0009] When such air bags are deployed, depending upon their specific location or application, they may be subjected to pressures within a relatively broad range. For example, air bag deployment pressures are generally in the range of from about 50 kilopascals (kpa) to about 450 kpa, which corresponds generally to a range of from about 7.4 pounds per square inch (psi) to about 66.2 psi. Accordingly, there is a need for fabric products and air bags which can be made to be relatively impermeable to fluids under such anticipated pressures while being relatively light in weight.
[0010] One means of improving air holding capability in vehicle restraint systems has been through coatings such as chloroprene and silicone rubber coatings, applied to the textile substrate. Wherever coated fabrics are used there exists the problem of insufficiency of adhesion of the coating to the fabric substrate. More particularly, the smoother the substrate surface, generally the more difficult it is to obtain strong adhesion of the coating material to the substrate. Furthermore, with some coatings such as silicone rubber, radio frequency (RF) heat sealing techniques cannot be used to form the bag. Thus, in such instances bags are usually made by stitching, a process which requires the addition of an adhesive sealant in the stitched areas.
[0011] There have recently been developed improved polyurethane, acrylic, polyamide and silicone coatings that are coated in layers on the fabric substrates. It has been found that adhesion characteristics are greatly improved with such layered coatings. Examples of such coated fabrics and methods of coating such fabrics are disclosed in commonly assigned application Ser. Nos. 09/327,243, 09/327,244 and 09/327,245, filed Jun. 7, 1999, the disclosures of which are incorporated herein by reference and made a part of this disclosure.
[0012] In general, yarn sizes are measured by a well known weight indicator referred to as “denier” and identified as units “D”. The greater the denier (D), the thicker and heavier is one unit of length of the yarn. The most common denier yarns presently used in such air holding devices are 420D nylon, in a 46×46 or 49×49 count weave, for driver side air bags, and 630D nylon, in a 41×41 count weave, for passenger side air bags. However, deniers as low as 210D, in a 72×72 count weave, have been used where the air bag must be housed in a tight fit, and, to a lesser extent, a 315D yarn, in a 60×60 count weave.
[0013] U.S. Pat. No. 5,704,402 discloses an uncoated air bag fabric in which weave constructions are stated to provide air bags with air permeability which does not increase by more than about fifty percent from the untensioned state when the fabric is subjected to tensile forces. These textile fabrics are stated to include yarns of different deniers within the weaves. Air bags of this type are typically used as passenger side air bags and are unsuitable for use in driver side air bags or side curtains, which must have little or no air permeability.
[0014] U.S. Pat. No. 5,863,644 discloses woven or laid structures using hybrid yarns comprising reinforcing filaments and lower melting matrix filaments composed of thermoplastic polymers to form textile sheet materials of adjustable gas and/or liquid permeability. During the formation of textile fabrics in accordance with the disclosure, polyester fibers in the weaves are melted by the application of heat to form textile sheet materials which are stated to have predetermined gas and/or liquid permeability.
[0015] U.S. Pat. No. 5,881,776 relates to a rapier woven low permeability air bag fabric and an air bag for use in a motor vehicle. The fabric is of plain weave construction and has an air permeability of less than approximately 5.0 CFM. The air bag is comprised of a plurality of panels connected together about their respective peripheries.
[0016] While these known fabrics represent somewhat successful attempts to control permeability through the incorporation of one or more features, none of these attempts have adequately solved the problem of providing a fabric of adequate impermeability whereby controlled permeability may be incorporated, where required. The present invention relates to a mixed woven coated textile fabric having yarns of different denier sizes woven for use in such inflatable air bag or side curtain restraint systems which not only provides improved adhesion of the coating to the textile substrate, but more effectively limits permeability and provides enhanced physical properties of the woven substrate, yet leaving available controlled permeability through the use of selectively sized venting apertures or other means.
[0017] In addition to the foregoing, there has been described in U.S. application Ser. No. 09/921,979, filed Aug. 3, 2001, and its continuation-in-part application, Ser. No. 10/038,207, filed Jan. 4, 2002, both of which disclosures are incorporated by reference herein and made a part of this disclosure, a laminated multi-layered woven product having preconfigured air holding cavities. This product is known in the industry as a one piece woven (OPW) air bag or curtain. The present invention provides an improved laminated one piece woven air bag or curtain resulting from the use of multi-denier textiles, which imparts greater reinforcement and bonding properties to the product.
SUMMARY OF THE INVENTION
[0018] It has been found that by weaving yarns of different deniers, as for example, a low 15 denier yarn with a higher denier yarn of the same or different continuous filamentary or fibrous materials in either or both of the warp or fill directions, coating adhesion and other physical properties of the woven textile fabric are greatly improved. In particular, if for example, nylon yarns of different deniers are interwoven, the difference in deniers creates an uneven, or relatively rough surface to which polymer coatings will adhere more securely than if the surface were smooth. Further, if nylon yarns of one denier are interwoven with, for example, yarns of a different denier and different fiber material, such as aramid fiber, the woven textile fabric would not only have greater adhesion capability for coatings, but would also have increased puncture resistance properties. In addition, the use of low denier yarns woven with high denier yarns greatly improves the packageability of the air bag or side curtain for storage, while reducing the weight of the bag. Broadly stated, fabrics for such air bags generally can weigh from about 4.0 ounces per square yard (osy) to about 10.0 ounces per square yard (osy). In actual use, however, on the average, fabrics for such air bags generally weigh from about 5 to about 6 ounces per square yard. It has now been found that by combining different size and types of yarns in a single fabric weave, the strength and weight of the resultant fabric can be selectively controlled. For example, yarns of a given denier can be utilized in the warp with yarns of a lesser denier in the fill direction. Also, the warp yarns can be comprised of yarns of different deniers in an alternating regular or random fashion and the fill yarns can be comprised of yarns of the same denier or of varying or alternating deniers. Moreover, individual yarns can be comprised of continuous filaments of varying sizes blended together, or blended with other natural or synthetic fibers to control strength and weight factors inherent in the final fabric product. As will be seen hereinbelow, such combinations provide not only strength and weight benefits, but also surface adhesion properties for coating the fabrics to render them substantially impermeable to fluid pressure.
[0019] A coated woven textile fabric is disclosed, which comprises synthetic yarns of more than one denier, and a polymeric coating on at least one side thereof, the yarns and the polymeric coating being preselected respectively in deniers and thickness so as to render the fabric substantially impermeable to fluid under pressure. According to one preferred embodiment the fabric is comprised of warp yarns of about 315D nylon and fill yams of about 210D nylon. According to another embodiment the fabric is comprised of warp yarns of about 420D nylon and fill yarns of about 315D nylon. According to yet another embodiment the fabric is comprised of warp yarns of from about 315D to about 420D nylon and fill yarns of from about 195D to about 380D aramid.
[0020] An embodiment of the invention is disclosed wherein the fabric is comprised of warp yarns of more than one denier and fill yarns of more than one denier. This fabric may be comprised of warp yarns of from about 210D to about 315D nylon and fill yarns of about 210D nylon, and the yarns are selected from the group consisting of nylon, polyester, aramid and graphite and combinations thereof.
[0021] The coating on at least one side of the fabric is preferably a thin polyurethane layer, but may also be comprised of polysiloxane, polyamide or acrylic type polymers. The same or an alternative coating may be provided on the other side of the fabric. It has been found that the coated fabric according to the invention provides excellent fluid impermeability while retaining packageability and anti-blocking qualities.
[0022] A flexible lightweight air bag for receiving and containing fluid under pressure for use in a vehicle air restraint system is also disclosed, which comprises a textile fabric according to the invention which is woven of synthetic yarns of more than one denier, and has a polymeric coating on at least one side of the fabric. The yarns and the polymeric coating are preselected respectively in deniers and thickness so as to render the air bag capable of receiving and retaining fluid under pressure in a vehicle air restraint system. The polymeric coated fabric is substantially impermeable to the fluid.
[0023] The coating on at least one side of the fabric is preferably a thin polyurethane layer, but may also be comprised of polysiloxane, polyamide or acrylic type polymers. The same or an alternative coating may be provided on the other side of the fabric forming the air bag. It has been found that the fabric according to the invention provides excellent fluid impermeability while retaining packageability and anti-blocking qualities.
[0024] In another embodiment of the present invention, fibers and yarns of different materials and denier sizes are woven into a one piece air bag structure having preconfigured air holding pockets and laminated with a film having adhesive and sealing properties. Weaving the side air curtains directly on a loom to produce a multi-layered woven product having pre-configured air holding cavities is much more economical in terms of cost of production and ease of shipping than sewing or welding pre-configured pieces of coated textile fabric. Pre-configured woven side air curtains require minimal cutting and essentially no joining of separate pieces, and are ready for coating as they come off the loom. Since the multi-layered fabric is woven from uncoated yarn, the curtain must be coated after weaving to impart the desired sealing and adhesive properties to the product. The difficulty inherent in coating a pre-configured multi-layered woven product is that the liquid coating material, e.g. polyurethane, can soak through the outer layers of woven fabric and penetrate the interior of the curtain. When this occurs and the coating hardens with heat and pressure, the sides of the curtain will stick together, preventing or substantially hindering the opening of the air pockets and deployment of the curtain when it is needed. Moreover, in order to make the side air curtain impermeable to air, the coatings require large concentrations of polysiloxane or other rubber-like materials, which produce a very heavy and bulky curtain that is not easily folded and stored. The use of multi-denier fibers and yarns in one piece woven (OPW) air bags and side air curtains provides these structures with all of the advantages imparted to the coated air bag fabrics that are discussed herein. The use of multi-denier fibers and yarns in the manufacture of OPW structures imparts additional needed strength to the seams and substantially improves their adhesion and bonding characteristics.
[0025] In the manufacture of one piece woven (OPW) air bag structures, a solid polymeric film is laminated to the outer surfaces thereof to make it air tight to very high pressures for extended periods of time. In the process of making the air curtains of this invention, an adhesive polycarbonate, polyether, or polyester aliphatic polyurethane prime coat layer is first coated onto a multi-denier woven textile substrate having preconfigured air holding cavities. A solid polymeric film, such as polyamide, polyolefin, polyether, polyester, polycarbonate or polyurethane, is laminated to the outer surfaces of the structure. In one embodiment of the invention, an adhesive prime coat layer is applied to the surface of the textile substrate, which can be woven nylon, polyester, or other synthetic fibers, through rotogravure or direct coating and allowed to dry. A solid polymeric film, such as polyamide, polyether, polyester, polycarbonate, polyolefin or polyurethane film, is then applied to the prime-coated textile substrate by means of hot film lamination, through the use of heat and pressure.
[0026] In an alternative embodiment of the invention, a multi-layered composite film product, whose structure and method of production is disclosed in co-pending application Ser. No. 10/038,207, which is incorporated by reference herein, can be used as a film laminate without the need for first applying a prime coat adhesive layer to the textile substrate. In this connection, the adhesive prime coat and the polymeric film laminate are applied to the multi-denier woven textile substrate in a single step via the film laminate itself. The methods and products of this invention thus permit an automotive protective device such as a side air curtain to be pre-configured or prefabricated to numerous varied designs and shapes prior to coating which will result in economies of operation and reduce the cost of manufacturing these devices.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] Preferred embodiments of the invention are described hereinbelow with reference to the drawings, wherein:
[0028] [0028]FIG. 1 is a partial cross-sectional side elevational view of a driver's side of an automobile showing a deployed air holding restraint bag made of the lightweight textile fabric constructed according to the present invention;
[0029] [0029]FIG. 2 is a greatly enlarged, partial schematic representation of a lightweight woven fabric of the invention, comprised of nylon yarns of different deniers;
[0030] [0030]FIG. 3 is a cross-sectional view of the fabric of FIG. 2, taken along line 3 - 3 of FIG. 2, with a polymeric coating added to one side thereof;
[0031] [0031]FIG. 4 is a greatly enlarged partial schematic view of an alternative embodiment of the lightweight woven fabric of the invention, comprised of nylon yarns of alternative different deniers;
[0032] [0032]FIG. 5 is a cross-sectional view of the fabric of FIG. 4, taken along line 5 - 5 of FIG. 4 with a polymeric coating added to one side thereof;
[0033] [0033]FIG. 6 is a greatly enlarged partial schematic view of another alternative embodiment of the lightweight fabric of the invention, comprised of nylon and aramid yarns of different deniers;
[0034] [0034]FIG. 7 is a cross-sectional view of the fabric of FIG. 6, taken along line 7 - 7 of FIG. 6, illustrating an alternative embodiment of the invention wherein a polyurethane coating is added to both sides of the fabric;
[0035] [0035]FIG. 8 is a greatly enlarged view of still another alternative embodiment of the lightweight fabric of the invention, comprised of blended yarns of synthetic filamentary materials and natural fibrous materials such as nylon and cotton yarns of different deniers; and
[0036] [0036]FIG. 9 is a cross-sectional view of the fabric of FIG. 8, taken along line 9 - 9 of FIG. 8, with a polymeric coating added to one side thereof.
[0037] [0037]FIG. 10 is a top plan view of a position of a sheet of the multi-layered woven textile substrate unwound from a supply roll, showing multiple units of pre-configured side air curtains with air holding cavities;
[0038] [0038]FIG. 11 is a cross-sectional view of the multi-layered, pre-configured textile substrate shown in FIG. 1 with film lamination;
[0039] [0039]FIG. 12 is a cross-sectional view of one embodiment of the composite film laminate of the invention;
[0040] [0040]FIG. 13 is a schematic plan view of a multi-layered textile substrate with a pre-configured construction showing exemplary tethers and one exemplary dead air zone;
[0041] [0041]FIG. 14 is a schematic cross-sectional view of a multi-layered textile substrate of a pre-configured construction, with tethers;
[0042] [0042]FIG. 15 is a schematic cross-sectional view of a tethered air curtain; and
[0043] [0043]FIG. 16 is a schematic plan view of a multi-layered air curtain, illustrating another embodiment of tether.
DETAILED DESCRIPTION OF THE INVENTION
[0044] According to the present invention it has been found that coated multi-denier mixed woven textile fabrics for use in inflatable air bags or side curtains, whether of the same or different materials, provide greatly improved coating adhesion and other desired physical properties over a textile fabric woven from yarns of the same denier. In particular, it has been found that a combination of woven yarns of differing deniers form a fabric having ridges and valleys in the weave which provide a much greater surface area for adhesion of synthetic polymeric coatings to the woven substrate which, in turn, increases the adhesion of the coating material to the woven fabric substrate. Further, the textile material of the present invention can be woven to specific tensile strength or puncture resistance requirements by selectively increasing or decreasing the denier sizes of the yarns or by introducing puncture resistant or other types of materials into the weave.
[0045] Although the preferred textile materials for use in air bags are yarns of nylon and polyester, other synthetic materials can be used according to the invention. For example, aramid yarns such as Kevlar®, produced by E. I. DuPont de Nemours & Company, Spectra® produced by Allied Signal Corporation, or PBI®, produced by Celanese Corporation, can be used in the weave. Non-polymeric materials such as graphite, natural fibers or blends of natural fibers such as cotton, and synthetic filaments such as polyester can also be used to advantage in the weave. It has been found that woven combination fabrics that incorporate aramid yarns provide greater puncture protection to the side curtain where danger from broken glass exists. Weave combinations, such as nylon and cotton, for example, can also be used to create different physical properties, such as providing additional flexibility to the coated fabric. Weaves of aramid yarns alone may also be used in the invention. In general, the synthetic yarns are each formed of bundles of continuous filaments temporarily held together for weaving by a suitable sizing compound such as polyvinyl alcohol, which also provides lubricity for weaving. After weaving, the sizing compound is generally removed from the fabric by a known scouring process. Polymeric coated fabrics for uses in air-holding vehicle restraint systems and methods of coating such fabrics are disclosed in the aforementioned commonly assigned application Ser. Nos. 09/327,243, 09/327,244 and 09/327,245, filed Jun. 7, 1999, which are incorporated herein by reference.
[0046] When the woven textiles of the present invention are coated as, for example, with polyurethane, silicone rubber, polysiloxane, or polyamide and acrylic type polymers, the air holding characteristics of the woven textile can be adjusted as required such as by vents or other appropriate means for the particular application involved. This allows for the use of different denier materials to be used for the driver side and front passenger type air bags than those that are used for the side curtains. Also, the thickness of the polymeric coating can be pre-selected to be combined most effectively with yarns of differing and preselected deniers to provide a coated fabric which is most effective in terms of pressure fluid impermeability, packageability, puncture resistance and the like.
[0047] The yarns of the present invention can be of deniers ranging from about 70D to about 1200D to produce products having weave counts of from about 20 to about 150 yarns per inch. Textile weights can range from about 4.0 to about 10.0 ounces per square yard (osy). These types of multi-denier weave combinations exhibit improved tear resistance and adhesion on lightweight denier textiles to be used in air bag and side curtain applications. Higher denier nylon and aramid yarns provide greater tear resistance. In addition, these types of denier combinations and constructions can be woven with unsized yarns utilizing LDPF (low denier per filament) Hi-tenacity yarns, manufactured by DuPont, or with high shrinkage yarns. The woven textiles of the invention can also be blends of aramid yarn with nylon, polyester or other synthetic yarns.
[0048] For purposes of this invention, weaves of different types are contemplated, such as, for example: plain weaves, consisting of yarns in an alternating fashion, one over and one under every other yarn; basket weaves, in which two or more warp yarns are alternately interlaced over and under each other; leno yarns, in which the yarns are locked in place by crossing two or more warp threads over each other and interlacing with one or more filling threads; twill weaves, characterized by a diagonal rib created by one warp yarn floating over at least two filling yarns; four harness satin weave where a filling yarn floats over three warp yarns and under one; an eight harness satin weave, which is similar to the four harness satin weave except that one filling yarn floats over seven warp yarns and under one; and high modulus weave where high impact resistance and high strength are required. Detailed descriptions of such weaves are described in textile publications such as a publication of Clark-Schwebel Joint Ventures, CS-Interglas A. G., the disclosure of which is incorporated herein by reference.
[0049] A preferred construction for the multi-denier weave of the invention is a plain weave of 315D×420D nylon, with a weave count of 46×46. A weave of this construction has been found to provide greatly improved adhesion characteristics, better packageability and excellent tensile strength. As disclosed herein, other deniers can be used within the ranges specified to provide the advantages of the invention. Similarly, when a combination of different yarns is used in the weave, such as nylon and aramid yams, the preferred weave would be a warp nylon of 315D or 420D with a 195D or 380D Kevlar® yarn. In general, it has been found that by combining low denier yarns with high denier yarns, the lower denier yarns reduce the weight of the fabric, yet the fabric retains the benefits of strength and weight through the high denier yarns incorporated therein.
[0050] Referring now to FIG. 1, there is shown a partial cross-sectional side elevational view of a driver's side of an automobile 10 showing a deployed air restraint bag 12 made of a lightweight coated fabric constructed according to the present invention. The air bag is preferably constructed of a plain weave fabric as will be described hereinbelow, coated on one side with a thin layer of polyurethane. The coating is preferably 0.001 to 0.010 inch in thickness (i.e., 1-10 mils), but may be up to about 0.020 inch in thickness (i.e., 20 mils) without substantially compromising packageability. The air restraint bag shown is exemplary of a driver's side air bag which is deployed from the steering column of the vehicle. Although not shown, as noted previously, air restraint systems including side curtains are also contemplated within the scope of the invention.
[0051] One preferred embodiment of the invention, is shown in FIG. 2, in which a lightweight woven fabric 14 is comprised of nylon yarns 16 of 315D in the warp direction and nylon yarns 18 of 210D in the fill direction. This blend, when coated with a polymeric coating 20 such as polyurethane, as shown in FIG. 3, provides a woven textile air bag fabric of the type shown in FIG. 1, with little or no permeability, improved packageability and strength, as well as improved coating adhesion properties. In particular, warp yarns 16 and fill yarns 18 are comprised of bundled nylon continuous filaments having little or no twist and held together by a suitable sizing agent such as polyvinyl alcohol, a compound which provides lubricity for weaving. The resulting fabric is as shown with yarns which are actually woven together in close proximity to permit little or no air permeability between the yarns. The greatly enlarged representation in the drawings are presented for illustration purposes whereby the spaces between the yarns are also greatly enlarged. In particular, it has been found that the particular construction of yam deniers disclosed herein, combined with the stated preferred coating thickness, provides substantial impermeability to fluid under pressure, while retaining high strength, low weight, superior packageability and non-blocking qualities. Moreover, the fabric's puncture resistance can be modified by combining aramid fibers such as Kevlar® into the weave.
[0052] In FIG. 3, a significant feature of the weave of FIG. 2 is illustrated by enlarged cross-sectional view, in that the different size yarns create a relatively uneven surface, with small crevices and interstices which more readily promote adhesion of the polyurethane coating 20 to the fabric 14 as shown. Other coating materials such as chloroprene and silicone rubber or the like have been found to adhere to the subject fabric with comparable improvement.
[0053] In FIG. 4 there is shown a weave 22 of nylon yarns 24 of 420D in the warp direction 20 and nylon yarns 26 of 315D in the fill direction. This combination of yarn weights would more commonly be used in driver side air bags or side curtains. Moreover, the weave shown in FIG. 4 provides much greater adhesion for coatings than a weave comprised entirely of a yarn of only one denier, as is evident from the enlarged cross-sectional view of the fabric shown in FIG. 5, with coating 28 of polyurethane added thereto on one side. Alternatively, the same type of coating may be placed on the opposite side of the fabric.
[0054] In FIG. 6 there is shown a greatly enlarged view of a woven fabric 30 of nylon and aramid yarns in which the warp yarns 32 are comprised of 310D nylon and fill yarns 34 are aramid yarns such as 195D Kevlar® brand aramid yarns. This weave provides improved adhesion of the polymeric coating by providing peaks and valleys between the yarns, as well as small crevices and interstices therebetween, all facilitated by the combination of different yarn sizes. Also greatly improved puncture resistant properties are provided by the nylon and the aramid yarns which renders the material especially suitable for side curtains. It should be understood that weaves in which the aramid yarns are woven in the warp direction are contemplated in this invention as well. Referring to FIG. 7 there is shown a cross-sectional view of the woven fabric shown in FIG. 6, showing the multi-filament nylon yarns 32 in cross-section which are greater in size—preferably twice the size—than the Kevlar® fill yarns 34 . In FIG. 7, there is also illustrated still another alternative embodiment of the present invention whereby polymeric coatings 36 , 37 are respectively added to each side of the fabric as shown. It has been found that the improved adhesion between the fabric 30 and the coatings 36 , 37 , combined with the combination of yarn sizes as disclosed herein, provides a fabric having little or no fluid permeability without compromising packageability. Accordingly, the fabric shown uncoated in FIG. 6 will provide a finished air bag having superior qualities when coated on both sides in FIG. 7.
[0055] Referring now to FIG. 8, there is shown a top plan view greatly enlarged, of a weave construction 40 of a combination of yarns comprised of warp yarns 40 of 315D nylon continuous filaments blended with cotton fibers with standard twist to retain the fibers and the continuous filaments together in yarn form. In the woven fabric of FIG. 8, the blended yarns 40 in the warp direction are about 315D and the blended yarns 44 in the fill direction are about 160D, or about one half the denier of the blended warp yarns 40 . FIG. 9 is a cross-sectional view taken along line 9 - 9 of FIG. 8, with polyurethane coating 44 added on one side to promote impermeability.
[0056] It should be understood that yarns of other synthetic and natural fibers can be used in the invention. In particular, yarns of polyester fibers are contemplated, with weaves of different denier sizes as with nylon. One example of a polyester fabric of the invention would be a weave of 440D polyester with a 650D polyester. Blended yarns of polyester and cotton are also contemplated for use in the invention. Other blends and weaves can also be used in the invention. For example, yarns of different size deniers can be used in either or both of the warp and fill directions. Thus, a weave could comprise both 210D and 315D nylon yarns in either or both of the warp and fill directions. Other denier and fiber combinations are contemplated herein and can be used in the invention.
[0057] As can be seen, the present invention provides a coated woven multi-denier textile fabric for use in an air bag or side curtain having substantially improved adhesion and physical properties. Such fabrics may be of the same or different yarns and of two or more deniers. Moreover, as noted, various combinations of yarn deniers and sizes can be utilized in the fabric to control strength and weight factors. For example, as noted, different combinations of yarn deniers can be utilized in both the warp and the fill directions, depending upon the intended application. Moreover, the actual yarns can be comprised of continuous synthetic filaments of different sizes, or filaments and natural or synthetic fibers of different sizes blended to form the yarn.
[0058] In addition, when a solid polymeric film of polyamide, polyolefin, polyether, polyester, polycarbonate or polyurethane material has been hot laminated to the surface of a multi-denier OPW textile having pre-configured air holding cavities to produce a side air curtain, the air holding characteristics of the protective device are substantially improved and it will hold air at very high pressures for extended periods of time. The multi-denier textile substrate can be a woven nylon, polyester, or other synthetic fibers, all of which are well known in the art to be useful in the manufacture of air bags and side air curtains. The surface of the textile substrate to be film laminated is first coated with an adhesive prime coat to seal the fabric and provide a base to which an overlying solid polymeric film layer can be adhered. The prime coat material is formulated to be suitable for coating the textile fabric without soaking through to the interior of the air holding cavities and thus causing sticking or blocking, which would prevent its opening when the air bag is activated.
[0059] The adhesive polyurethane prime coat comprises a solution of an aliphatic or aromatic polyester polyurethane or polyether polyurethane based material or a polycarbonate based aliphatic polyurethane that is compounded with other materials such as weight stabilizers, heat stabilizers, flame retardants, colorants and blocked isocyanate. The presence of isocyanate is important because when sufficient heat and pressure is applied to the prime coat composition, the isocyanate becomes adhesively activated. At that point in the process the polyurethane reacts with and adhesively binds the overlying polymeric film layer. The result is a thermoset film-prime coat composite which adheres to the textile fabric, seals it, and makes it air tight and able to withstand high pressures for the relatively long periods of time required of an air curtain. The seams of such a structure exhibit increased strength and are better able to withstand the extreme pressures of inflation when activated.
[0060] Another prime coat adhesive composition comprising a solution of polycarbonate polyurethane, a hot melt polyurethane and an isocyanate, results in greatly improved bonding, heat resistance and heat aging properties in the film-laminated textile fabrics of the invention. The polycarbonate polyurethane provides bonding strength to the adhesive, so that the film laminate will firmly and securely adhere to the textile fabric, even after storage at elevated temperatures for extended periods of time. The hot melt polyurethane acts as an adhesion promoter by enabling the prime coat composition to flow smoothly and completely over the portion of the textile fabric that is to be laminated, thus ensuring a complete sealing of the side air curtain. The isocyanate provides a heat setting or cross linking function to the adhesive composition and serves to bond the film laminate to the fabric.
[0061] More specifically, the polycarbonate polyurethane component is a polycarbonate polyol-based aliphatic polyurethane. The hot melt component comprises a polyester or polyether-based polyurethane or copolymer blends of ethylene vinyl acetate (EVA). The isocyanate component is a blocked HDI isocyanate (hexamethylene diisocyanate), such as the HDI isocyanate manufactured by Bayer Corp. of Pittsburgh, Pa. To this prime coat adhesive composition may be added such additional materials as antibacterial additives, flame retardants, colorants, weight stabilizers and finely ground silica, such as Aerosil 380 , which may be obtained from the Degussa Corp. of Ridgefield, N.J., and which serves as a reinforcement for the adhesive material.
[0062] The polycarbonate component provides bonding strength at elevated temperatures and improved heat aging properties. The hot melt component provides superior flow characteristics to the composition. However, too much of the hot melt component can result in reduced strength and heat aging properties, so its relative part-by-weight in the composition has to be adjusted carefully in relation to the polycarbonate polyurethane component of the mixture. The isocyanate component cross links with the polycarbonate and the hot melt components at the temperature and pressure of lamination. In general, the greater the amount of isocyanate present in the composition, the faster the adhesive sets. The part-by-weight ratio of isocyanate in the composition can vary from about 1:15, depending upon how fast it is desired to set the adhesive material. However, it is important that the adhesive prime coat not set or cure before the lamination step in the process.
[0063] In the film lamination of the invention, a solid polyamide, polyolefin, polyether, polyester, polycarbonate or polyurethane film is laminated to the surface of a prime-coated multi-layered woven textile fabric or to both outer surfaces of a prime-coated, pre-configured, multi-layered woven textile fabric to produce a film-textile-film laminate. The polymeric film laminate of the invention has a thickness of from about 0.2 mils to about 5.0 mils, and preferably from about 0.5 mils to about 1.0 mils. In one embodiment of the invention, as shown in FIG. 10, a one-piece woven multi-layered, multi-denier textile fabric 10 , having a multiplicity of pre-configured side air curtains C, air vents V, and woven inflation inlets 213 is prime-coated on both top and bottom outer surfaces, dried, without activating the isocyanate, and later laminated on both outer surfaces under heat and pressure with a polyamide, polyolefin, polyester, polyether, polycarbonate or polyurethane film. The film laminate has a thickness of from about 0.2 mils to about 5.0 mils, with from about 0.5 mils to about 1.0 mils being preferred.
[0064] A cross-section of the laminated multi-layered woven textile fabric taken across line 11 - 11 of FIG. 10 is shown in FIG. 11, wherein polymeric film coatings 111 and 112 are shown laminated on sides B and A, respectively, of textile fabric 110 . The adhesive prime coat layer 109 , which can be any of the above-mentioned adhesives of this invention, is shown between the film layer and the textile fabric. Suitable tethers 134 are provided to limit expansion of the fabric layers when the protective device is explosively deployed, and to maintain the desired expanded shape of the air curtain. Integrally woven connectors 144 and 145 between the multi-layered portions of the device are shown in FIG. 11.
[0065] In an alternative embodiment of the invention, a multi-layered woven textile fabric is laminated by film transfer with a composite film structure that comprises both the polymeric film layer and the adhesive prime coat layer. In this embodiment, the composite film is applied to a multi-denier OPW textile fabric in one step rather than two, thus eliminating the need for a separate prime-coating step. As shown in FIG. 12, the composite transfer film 120 is formed by casting a solution of polyamide or aromatic or aliphatic polyether polyurethane or polyester polyurethane, a polycarbonate or polyamide material onto release paper 121 . The carrier film layer 122 , when solidified, becomes the film laminate of the invention, and has a thickness of from about 0.2 mils to about 5.0 mils, with from about 0.5 mils to about 1.0 mils being preferred. Typical solvents for the carrier film layer or film laminate are toluene, xylene, and dimethyl formamide (DMF). An adhesive prime coat layer 123 comprises a solution of an aliphatic or aromatic polyester or polyether polyurethane based material or a polycarbonate based aliphatic polyurethane compounded with other materials, is coated onto carrier film layer 122 after it (the film laminate) has been solidified. The prime coat layer has a thickness of from about 0.5 mils to about 5.0 mils, with from about 1.0 mils to about 1.5 mils being preferred. When the coating process has been completed and the film composite dried, the release paper is stripped away and it can then be laminated to the multi-layered multi-denier woven textile substrate.
[0066] The film-laminated multi-woven textile substrate when inflated will be substantially air tight. When deployed, these protective air bags are designed to hold air during a rollover accident for the entire rollover period. When laminated in accordance with this invention, air curtains having an initial inflation pressure of about 70-75 Kpa, will hold to a minimum of about 60 Kpa for about 10 to 12 seconds after inflation. Specific air cavity designs will alter the volume of air and the amount of pressure required. These multi-layered multi-denier textile substrates are designed to have different air cavity configurations and different internal tether designs as shown in FIGS. 13 - 16 . In FIG. 13 there is shown a top plan view from the side of a multi-layered woven textile substrate with a pre-configured construction 130 of the invention, including a dead air zone 131 (not inflatable) and internal tethers 132 , 133 and 134 , which maintain the air curtain's configuration and keep it from pulling apart during inflation. FIG. 14 is a cross-sectional view of a multi-layered textile substrate 140 with internal air channels 141 , 142 and 143 , and integrally woven connectors 144 and 145 . Tethers 134 are provided to control expansion and maintain the desired shape of the air curtain.
[0067] [0067]FIG. 15 is a cross-sectional view of a tethered side air curtain 150 , showing internal tethers 151 , 152 and 153 which limit the expansion of the side air curtain and maintain the shape when in the expanded state.
[0068] [0068]FIG. 16 is a top plan view of a multi-layered tethered side curtain 160 , having a multiplicity of tethers, such as that shown at 161 . It is generally considered difficult to coat a multi-layered fabric similar to that shown in FIG. 8 with applied coating techniques or rotogravure direct coating without resulting in penetration of liquid adhesive through the textile material to the tethers. Unwanted gluing together of the tethers must be avoided because they are intended to open and expand when the bag is inflated.
[0069] In another embodiment of the invention, the multi-denier OPW air bag is woven in a manner so as to provide for venting of air entrapped during the lamination process described in commonly assigned U.S. applications Ser. No. 09/389,711 and No. 10/038,207, referred to above. In the lamination process described therein a roll of woven textile air bags having preconfigured air holding cavities is unrolled and pulled through a continuous coating and lamination line. In this process, the woven textile fabric is first coated with an adhesive polyurethane coating material and then laminated under heat and pressure with a solid polymeric film. At the point in the process in which the woven textile fabric is coated with an adhesive material, it is effectively sealed and the preconfigured air holding cavities therein entrap air and form air bubbles. The air bubbles so formed impede the lamination process in which a solid polymeric film is laminated to the coated textile fabric under heat and pressure.
[0070] In the inventive product herein, air vents are woven into the textile fabric at the place where the OPW air bag or side curtain will later be cut to form an inlet for the inflation tube that is required in the finished product. These air vents may be formed, for example, by weaving the textile fabric so that the fill yarns are not interlaced with the warp yarns but are instead overlaid thereon. The absence of interlaced yarns provides for expansion of the fabric at these points, which permits air to be expelled when the textile fabric is pulled through the rollers in the lamination process. As a result, air is forced out ahead of the polymeric film laminate, thus providing for a smooth, strong lamination of the product.
[0071] Referring to FIG. 17, a single multi-layered unit C of the one-piece woven, multi-layered, multi denier textile fabric shown in FIG. 10, is pulled in direction D in the lamination process. As the woven textile fabric is pulled through heat sealing rollers that are used to laminate the solid film thereto, air is forced back from the leading edge 211 of the unit toward the rear edge 212 of the unit and out of air vents 210 . These air vents are usually situated around the woven inlets 213 that are later cut in the manufacturing process for receiving the inflation tubes in the completed air curtains. When the film lamination process has been completed, the air vents become sealed by the polyurethane adhesive coating and the solid film laminate. Removal of entrapped air and the elimination of air bubbles produces a film laminate that is smooth and secure.
[0072] A single air vent V of the type 210 of FIG. 17 is shown greatly enlarged in FIG. 18. The air vent depicted therein shows warp yarns 214 , fill yarns 215 interlaced with the warp yarns 214 , and fill yarns 216 overlaying the warp yarns 214 . At those places in the woven textile fabric where air vents are required, the fill yarns overlay the warp yarns, rather than interlace with them, thus creating a loose and expandable weave, which permits air to be expelled even after a coating of adhesive polyurethane has been laid down on the fabric. After any entrapped air has been expelled through the air vents, the textile fabric is sealed with a solid film laminate and remains sealed until it is later cut at the woven inlet tube position on the unit to provide an opening for an inflation tube (not shown). It should be understood that the warp and fill yarns shown herein are of the multi-denier type that is disclosed herein and may be of the various types and deniers described above. It is contemplated that other weave designs or even holes that are cut or drilled into the textile fabric may be utilized in the manufacture of air vents, so long as they serve to provide a means for entrapped air to be expelled.
[0073] While the preferred embodiments of the invention have been illustrated and described, using specific terms, such description has been for illustrative purposes only, and it should be understood that changes and variations may be made without departing from the spirit and scope of the invention which is defined by the claims appended hereto. | A woven textile fabric is disclosed which is formed of synthetic yarns of at least two different deniers to which a solid polymeric film is laminated. An adhesive polymeric coating is provided for adhering the solid polymeric film to the woven textile fabric. The combination of yarns of different deniers provides a superior adhesion surface for the polymeric film. The yarns and the polymeric coating are preselected respectively in deniers and thicknesses so as to render the fabric substantially impermeable to fluid under pressure, while maintaining superb packageability and anti-blocking properties for use in vehicle occupant restraint systems. An air bag incorporating the woven textile fabric of the invention and having two outer surfaces and pre-configured air holding cavities woven therein to which a solid polymeric film is bonded for receiving and containing fluid under pressure for use in a vehicle air restraint system is also disclosed. Air vents are provided for preventing entrapped air from forming bubbles in the lamination process. | 3 |
CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority from Korean Patent Application No. 10-2012-0119807, filed on Oct. 26, 2012, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.
BACKGROUND
1. Field
Embodiments consistent with the present disclosure relate to a tire pressure monitoring system.
2. Description of the Related Art
Abnormalities in tire pressure may cause a significant vehicle accident, such as a burst of a tire due to abnormal wear or heat generation on both sides of a tire tread, a decrease in handling stability, deterioration of gas mileage, or an occurrence of hydroplaning at a low driving speed. Therefore, monitoring a tire pressure is important in order to secure stability of a vehicle.
A tire pressure monitoring system (TPMS) is a device that informs a driver or another device of a vehicle of air pressures of tires, i.e., tire pressure. The TPMS helps to prevent insufficient tire pressure, or tire damage, from causing an accident and inefficient gas mileage.
SUMMARY
Embodiments provide a tire pressure monitoring system that is inexpensive, simple to install, and easy to maintain.
Additional aspects of the exemplary embodiments will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the presented embodiments.
According to an aspect of an embodiment, there is provided a tire pressure monitoring system including: a plurality of sensors which output sensing signals, the plurality of sensors including a printable pressure sensor which senses an air pressure of a tire, and a temperature sensor which senses an air temperature inside the tire; a signal processor which is configured to process the sensing signals output by the plurality of sensors; a wireless power receiver which is configured to receive energy from a power source and output power; and a rechargeable battery which is configured to be charged by the power output by the wireless power receiver and supply power to the plurality of sensors power to sense the air pressure of the tire and the air temperature inside the tire.
The printable pressure sensor may be configured to sense the air pressure of the tire by measuring a resistance or capacitance, according to a transformation of a space between two films due to a pressure of a tire dorsal part.
The space between the two films may be in a vacuum state, or is filled with a gaseous, liquid, or solid material.
The temperature sensor may include a structure in which a heat sensing part is stacked, trenched, or embedded with respect to a flexible substrate.
The heat sensing part may be configured to measure the temperature by coating heat sensing resistive particles in order to utilize a phenomenon in which a resistance increases according to the temperature.
The heat sensing resistive particles may include silver nanoparticles.
The heat sensing part may be configured to measure the temperature using a material having pyroelectricity in order to measure a voltage generated according to the temperature.
The material having pyroelectricity may include a Polyvinylidene Fluoride (PVDF).
The signal processor may include a circuit formed by printed electronics technology on a substrate formed of a polymer material, a flexible substrate, or a substrate of a complex structure of a solid substrate part and a flexible substrate part.
The wireless power receiver may include a resonance coil formed on a flexible substrate by a printed electronics method, coating, or electrolytic plating.
The flexible substrate may wind around a tire rim, and a pattern of the resonance coil is formed on the flexible substrate and connects both ends of a coil pattern of the resonance coil to each other to conduct electricity.
The both ends of the coil pattern may be connected to each other to conduct electricity by using a soldering, buttoning, or plugging method.
An antenna structure may be provided on one side of the flexible substrate by the printed electronics method, the antenna structure is configured to transmit the processed signals output by the signal processor.
At least one selected from a group consisting of the plurality of sensors, the signal processor, and the rechargeable battery may be provided on the flexible substrate by a printed electronics method.
At least one selected from a group consisting of the plurality of sensors, the signal processor, and the rechargeable battery may be provided on the flexible substrate in a chip on board (COB) form.
At least one selected from a group consisting of the plurality of sensors, the signal processor, and the rechargeable battery may be assembled on the flexible substrate.
The rechargeable battery may repeatedly rechargeable.
The rechargeable battery may be formed by a printed electronics method.
The rechargeable battery may be formed in a lithium-polymer or lithium-ion thin film structure.
According to an aspect of another embodiment, there is provided a tire pressure monitoring system mounted on a tire rim, the tire pressure monitor system including: a flexible substrate which is mounted on the tire rim; and the tire pressure including a sensor device which outputs sensing signals, the sensor device senses an air pressure of a tire and an air temperature of the tire; a signal processor which is configured to process signals output by the sensor device; a wireless power receive which is configured to receive energy from a power source and output power; and a rechargeable battery which is configured to be recharged by the power output by the wireless power receive and supply power to the plurality of sensor to sense the air pressure of the tire and the air temperature inside the tire.
BRIEF DESCRIPTION OF THE DRAWINGS
These and/or other aspects will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings in which:
FIG. 1 is a block diagram of major configurations of a tire pressure monitoring system (TPMS), according to an embodiment;
FIG. 2A is a top view of a printable pressure sensor applicable to a TPMS according to an embodiment;
FIG. 2B is a side cross-sectional view of the printable pressure sensor of FIG. 2A ;
FIG. 3A is a top view of a printable pressure sensor applicable to a TPMS according to another embodiment;
FIG. 3B is a side cross-sectional view of the printable pressure sensor of FIG. 3A , wherein upper and lower electrodes are formed on outer surfaces of two films;
FIG. 3C is a side cross-sectional view of the printable pressure sensor of FIG. 3A , wherein upper and lower electrodes are formed on inner surfaces of two films;
FIG. 4 is a front view of a temperature sensor applicable to a TPMS according to an embodiment;
FIG. 5A is a top view of an example in which a circuit of a signal processor is arranged on a substrate when the substrate is formed of polymer materials to which printed electronics technology is applicable or is a flexible substrate;
FIG. 5B illustrates an example in which a circuit of a signal processor is arranged on a substrate when the substrate has a complex structure of a solid substrate part and a flexible substrate part;
FIGS. 6 and 7 illustrate examples in which a resonance coil applicable as a wireless power receiver to a TPMS according to embodiments is implemented on a flexible substrate;
FIG. 8 is a schematic diagram of wireless power transmission;
FIG. 9 illustrates an example in which a printable and rechargeable flexible battery is formed together with other components.
FIG. 10 illustrates an example of a roll-to-roll method; and
FIG. 11 is a perspective view of a tire rim on which a TPMS according to an embodiment is mounted.
DETAILED DESCRIPTION
A tire pressure monitoring system (TPMS) according to embodiments will now be described in detail with reference to the accompanying drawings, wherein like reference numerals refer to like elements throughout the drawings, and sizes and thicknesses of components in the drawings may be exaggerated for clarity and convenience of description. 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. As used herein, expressions such as “at least one of,” when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list.
FIG. 1 is a block diagram of major configurations of a TPMS 100 , according to an embodiment.
Referring to FIG. 1 , the TPMS 100 includes a sensor unit 200 , a signal processor 300 , a wireless power receiver 400 , a wireless data transceiver 600 , and a rechargeable battery 500 .
The sensor unit 200 includes a plurality of sensors. For example, the sensor unit 200 may include a printable pressure sensor 210 for sensing an air pressure of a tire, and a temperature sensor 230 for sensing an air temperature inside the tire. The sensor unit 200 may further include various sensors, such as an acceleration sensor for sensing acceleration.
The printable pressure sensor 210 measures an air pressure inside the tire, and may sense the air pressure by measuring a resistance or capacitance according to a transformation of a space 212 between two films 211 and 213 , as shown in FIGS. 2A to 3C .
FIG. 2A is a top view of the printable pressure sensor 210 applicable to the TPMS 100 . FIG. 2B is a side cross-sectional view of the printable pressure sensor 210 of FIG. 2A .
Referring to FIGS. 2A and 2B , the printable pressure sensor 210 may have a structure in which a resistance varies according to a transformation. Therefore, the printable pressure sensor 210 may detect the transformation of the space 212 between the two films 211 and 213 by an air pressure of a tire. In other words, the space 212 may be formed between the two films 211 and 213 by forming a structure in which a partial area of one film 213 is expanded against the other film 211 . The film 213 , having the expanded structure of the two films 211 and 213 , may be formed of a flexible material to cause a transformation in the space 212 in response to the air pressure of the tire. Accordingly, a resistance, of a resistance change material pattern 216 formed on the film 213 , may vary. In this case, the space 212 may be in a vacuum state, or be filled with a gaseous, liquid, or solid material. When a resistance value varies according to a transformation in the space 212 of the printable pressure sensor 210 due to the air pressure of the tire, a transformation amount may be detected, and an air pressure may be determined from the detected transformation amount.
It may be determined whether the space 212 is in a vacuum state or is filled with a gaseous, liquid, or solid material according to a pressure inside the tire, and the thicknesses of the films 211 and 213 .
FIG. 3A is a top view of the printable pressure sensor 210 applicable to the TPMS 100 according to an embodiment. FIGS. 3B and 3C are side cross-sectional views of the printable pressure sensor 210 of FIG. 3A . FIG. 3B shows a case where upper and lower electrodes 216 and 217 are formed on the outer surfaces of the two films 211 and 213 , and FIG. 3C shows a case where upper and lower electrodes 216 and 217 are formed on inner surfaces of the two films 211 and 213 . Referring to FIGS. 3A to 3C , compared with the printable pressure sensor 210 of FIGS. 2A and 2B , the printable pressure sensor 210 of FIGS. 3A to 3C may be provided to sense an air pressure by measuring a capacitance, instead of the resistance change, according to the transformation of the space 212 between the two films 211 and 213 due to the air pressure of the tire.
In other words, the printable pressure sensor 210 may sense a transformation amount by forming the upper and lower electrodes 216 and 217 on the outer surfaces or inner surfaces of the two films 211 and 213 , or forming one of the upper and lower electrodes 216 and 217 on the outer surface of one of the two films 211 and 213 and the other one of the upper and lower electrodes 216 and 217 on the inner surface of the other one of the two films 211 and 213 to measure a variation of capacitance according to the transformation of the space 212 , instead of the resistance change material pattern 216 . An air pressure may be measured from the transformation amount. In this case, the measurement of the capacitance may be readout as a change in a voltage, detection of a current, or a predetermined change in a frequency.
Although FIGS. 2A to 3C show one sensor region of the printable pressure sensor 210 , the printable pressure sensor 210 may also include a two-dimensional array of such sensor regions.
Referring to FIG. 4 , in the TPMS 100 , the temperature sensor 230 measures an air temperature inside the tire. The temperature sensor 230 may be formed, for example, with a structure in which a heat sensing part 230 a is stacked, trenched, or embedded with respect to a flexible substrate 250 . FIG. 4 is a front view of the temperature sensor 230 applicable to the TPMS 100 according to an embodiment. FIG. 4 illustrates an exemplary structure in which the heat sensing part 230 a is stacked on the flexible substrate 250 . A protection layer or a conductive layer, having a good heat conductivity, may be further included on the heat sensing part 230 a.
The heat sensing part 230 a may measure a temperature by coating heat sensing resistive particles on the flexible substrate 250 . The heat sensing part 230 a may measure the temperature in order to use a phenomenon in which a resistance increases according to a temperature. The heat sensing resistive particles may include, e.g., silver nanoparticles.
As another example, the heat sensing part 230 a may measure a temperature using a material having pyroelectricity. In this case, the heat sensing part 230 a may measure a voltage generated according to a temperature. The material having pyroelectricity may include a PVDF Polyvinylidene-fluoride).
Referring to FIGS. 5A and 5B , in the TPMS 100 , the signal processor 300 includes a circuit 350 for processing signals detected by the plurality of sensors including the printable pressure sensor 210 and the temperature sensor 230 . The circuit 350 may be formed on substrates 310 and 330 by printed electronics technology. FIGS. 5A and 5B show cases where the circuit 350 of the signal processor 300 is formed on the substrates 310 and 330 . FIG. 5A shows an example in which the circuit 350 is arranged on the substrate 310 , when the substrate 310 is formed of polymer materials to which the printed electronics technology is applicable or is a flexible substrate. FIG. 5B shows an example in which the circuit 350 is arranged on the substrate 330 , when the substrate 330 has a complex structure of a solid substrate part 335 and a flexible substrate part 331 . In FIGS. 5A and 5B , the substrates 310 and 330 may be a printed circuit board (PCB) formed of all types of polymer materials, formed of a flexible material, or having a complex structure of a solid substrate part and a flexible substrate part.
The TPMS 100 may include the wireless power receiver 400 for wirelessly transmitting power to supply sufficient power in order to continuously observe an air pressure and a temperature. The TPMS 100 may also include the wireless data transceiver 600 for transmitting measured data, processed data, etc.
The TPMS 100 may have a structure implemented by print technology. As shown in FIGS. 6 and 7 , the TPMS 100 may implement print technology by integrating a structure of a resonance coil 450 and a structure of a wireless communication antenna 650 , for transmitting the measured data and processed data on a flexible substrate 700 .
In the TPMS 100 , the wireless power receiver 400 may include the resonance coil 450 . The TPMS 100 is, for example, mounted on a tire rim. As shown in FIGS. 6 and 7 , the resonance coil 450 may be implemented on the flexible substrate 700 . The resonance coil 450 on the flexible substrate 700 may be formed by printed electronics technology, and other methods, such as coating or electrolytic plating. As shown in FIGS. 6 and 7 , the resonance coil 450 may be formed by winding the flexible substrate 700 , on which a pattern of the resonance coil 450 is formed, around the tire rim and connecting both ends 450 a of the pattern of the resonance coil 450 to each other to conduct electricity. In this case, the both ends 450 a of the pattern of the resonance coil 450 may be connected to each other to conduct electricity by using a soldering method.
FIG. 8 is a schematic diagram of wireless power transmission. In FIG. 8 , S denotes a coil for wirelessly transmitting power of a power supply source A, and D denotes the resonance coil 450 . Power wirelessly transmitted through the resonance coil 450 is charged in the rechargeable battery 500 , thereby supplying sufficient power to monitor a tire pressure. A wireless power transmission distance may be valid up to tens of cm, with a power efficiency of tens of percentage points.
As shown in FIG. 7 , the wireless data transceiver 600 for transmitting measured data and processed data, the wireless communication antenna 650 for transmitting data and receiving data, which is formed at an arbitrary location in a printed electronics method, may be included. The wireless data transceiver 600 may further include a modem (refer to 670 of FIG. 11 ), in addition to the wireless communication antenna 650 for transmitting data and receiving data.
The TPMS 100 may further include the rechargeable battery 500 together with a wireless power transmission device, to supply sufficient power to monitor a tire pressure. The rechargeable battery 500 may be flexibly formed by a printed electronics method, together with the wireless power transmission device, i.e., the resonance coil 450 . When the rechargeable battery 500 is used, it may be possible to monitor an air pressure at a high performance by only wirelessly charging once for several weeks or months. The rechargeable battery 500 may be repeatedly recharged.
FIG. 9 shows an example in which a printable and rechargeable flexible battery is formed together, with other components. In this case, the printable and rechargeable flexible battery may be printed, coated, or embedded, and may be formed in a lithium-polymer or lithium-ion thin film structure.
FIG. 9 shows an example in which the rechargeable battery 500 , the circuit 350 of the signal processor 300 , and sensors, including the printable pressure sensor 210 and the temperature sensor 230 , are printed and formed on the flexible substrate 700 , on which the pattern of the resonance coil 450 is formed.
The TPMS 100 may be formed using a roll-to-roll method, an assembly method, etc., based on a printed electronics method, and may be mounted on a tire rim. FIG. 10 illustrates an example of the roll-to-roll method.
A method of manufacturing the TPMS 100 is not limited to a printed electronics method. All methods, such as coating, plating, deposition, etching, etc., may be used as long as the methods deal with a flexible substrate. Also, a mounting place is not limited to a tire rim. The TPMS 100 may also be formed as a tire side wall attachment type or a valve type.
In addition, the types of applied sensors are not limited to the printable pressure sensor 210 and the temperature sensor 230 . Therefore, other types of applied sensors may be applied as necessary, including an acceleration sensor, a humidity sensor, etc.
FIG. 11 is a perspective view of a tire rim 50 , on which the TPMS 100 is mounted, according to an embodiment. Like reference numerals denote like components.
Referring to FIG. 11 , the TPMS 100 has a structure in which the sensor unit 200 , including the printable pressure sensor 210 and the temperature sensor 230 , the circuit 350 forming the signal processor 300 , the rechargeable battery 500 , the resonance coil 450 forming the wireless power receiver 400 , the wireless communication antenna 650 and a modem 670 forming the wireless data transceiver 600 , etc., are arranged on the flexible substrate 700 . The flexible substrate 700 , on which these components are arranged, may be mounted on the tire rim 50 . Various chips 800 , such as a memory, a security chip, etc., may be further arranged on the flexible substrate 700 in a chip on board (COB) form. Another PCB 900 may be arranged in another area of the flexible substrate 700 . In addition, the sensor unit 200 , including the printable pressure sensor 210 and the temperature sensor 230 , the circuit 350 , and the rechargeable battery 500 may be arranged at a plurality of locations.
The components may be directly printed on the surface of the tire rim 50 , monolithically provided on the flexible substrate 700 , provided in a COB form on the flexible substrate 700 , or provided in an additionally assembled form.
At least one selected from the group consisting of the plurality of sensors including the printable pressure sensor 210 and the temperature sensor 230 , the circuit 350 , and the rechargeable battery 500 may be formed on the flexible substrate 700 by a printed electronics method.
At least one selected from the group consisting of the plurality of sensors including the printable pressure sensor 210 and the temperature sensor 230 , the circuit 350 , and the rechargeable battery 500 may be formed on the flexible substrate 700 in a COB form.
At least one selected from the group consisting of the plurality of sensors including the printable pressure sensor 210 and the temperature sensor 230 , the circuit 350 , and the rechargeable battery 500 may be assembled on the flexible substrate 700 .
In addition, the TPMS 100 , including necessary sensors, a signal processing circuit, the rechargeable battery 500 , the resonance coil 450 for wireless power transmission, and the wireless communication antenna 650 for data transmission and reception on the flexible substrate 700 , may be manufactured by the roll-to-roll method. Therefore, the TPMS 100 is cheap, easy to mount, and easy to maintain.
In addition, since it is necessary to charge the rechargeable battery 500 with power through the wireless power receiver 400 once, for several months or several weeks, a wireless power transmission system may be provided in a vehicle or mounted at a location other than a vehicle.
As described above, according to the one or more of the above embodiments, a cheap, easy to mount, and easy to maintain TPMS may be implemented by providing necessary sensors, a signal processing circuit, a rechargeable battery, a wireless power transmission resonance coil, and a data transmission and reception antenna on a flexible substrate in a monolithic manner, in a COB form, or in an additionally assembled form.
It should be understood that the exemplary embodiments described therein should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each embodiment should typically be considered as available for other similar features or aspects in other embodiments. | A tire pressure monitoring system (TPMS) is provided. The TPMS includes: a plurality of sensors which output sensing signals, the plurality of sensors including a printable pressure sensor which senses an air pressure of a tire, and a temperature sensor which senses an air temperature inside the tire; a signal processor which is configured to process the sensing signals output by the plurality of sensors; a wireless power receiver which is configured to receive energy from a power source and output power; and a rechargeable battery which is configured to be charged by the power output by the wireless receiver and supply power to the plurality of sensors to sense the air pressure of the tire and the air temperature inside the tire. | 1 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation of U.S. patent application Ser. No. 12/975,333 filed Dec. 21, 2010 now U.S. Pat. No. 8,251,074, which is a continuation-in-part of U.S. patent application Ser. No. 12/363,117 filed Jan. 30, 2009 now U.S. Pat. No. 8,307,836, which is a continuation-in-part of U.S. patent application Ser. No. 12/025,249 filed Feb. 4, 2008 now abandoned, all of which are incorporated by reference in its entirety.
BACKGROUND
1. Field of the Invention
Embodiments of the present invention generally relate to adjustable applicators. More particularly the invention relates to applicators that can be adjusted as per user's convenience for application of a cosmetic or a care product.
Applicators of the present invention can be employed in application of various products, such as for viscous cosmetics, for coloring strands of hair, and for dental flossing or for applying pharmaceuticals or cleaning agents.
2. Description of the Related Art
Various applicators for applying a substance are known. There are certain application areas where there is a requirement of curving the applicator as per user's convenience. Some such areas include application of mascara or in the cleaning of dental interstices. Majority of the existing applicators for such usages are pre-curved at a certain angle. For example U.S. Pat. No. 4,326,548 to Wagner discloses an oral hygiene tool comprising of a pen barrel shaped holder that carries a curved dental pick. Another example is that of U.S. Pat. No. 6,082,999 to Tcherny et. Al. which discloses a reusable flexible interdental device that has advantages of a toothpick and an interdental brush and also provides flexibility in two mutually perpendicular directions. However, the flexibility achieved is not controllable by the user. Therefore, there exists a need for a personal oral hygiene tool which can be used as per convenience by the user.
Also, mascara, an important make-up accessory used to darken and define eyelashes to accentuate the eyes, is difficult to apply because of the target area of application. The eyelashes offer a very small application area, while being soft, flexible, delicate and in close proximity to very sensitive eye tissue. Therefore, a mascara product would be liked by the consumers when a right kind of applicator is provided to them for easy application as the overall consumer experience depends on both the product and on the applicator used to apply it.
Mascara applicators such as twisted wire mascara brushes, curved mascara brushes and adjustable mascara applicators are known in the art. Curved mascara brushes permit contact of the brush with more eyelashes along a correspondingly curved eyelid. However, the rigid curved brush is a more difficult instrument to learn to use in the confines of the eye area, particularly the corners of the eye where a straight brush works better. Another drawback of pre-curved brush is that it is not readily adjustable to conform to a particular user's eyelid curvature. In addition, the curvature of the upper and lower eyelids is rarely the same and a brush curved to fit the upper lid will not properly fit the lower lid.
Adjustable mascara brushes are known in the prior art. It is known to provide adjustment of the angle of the brush or applicator relative to the applicator wand or handle as in U.S. Pat. No. 4,428,388 to Cassai et al. and the amount of brush exposed as in U.S. Pat. No. 4,598,723 to Cole.
U.S. Pat. No. 5,137,038 to Kingsford discloses an adjustable mascara applicator which can be adjusted by a user from straight to curved by the help of an extendable rod which is slidably disposed in the applicator wand. This rod may be straight to straighten a precurved applicator or curved so as to impart curvature to a straight applicator.
U.S. Pat. No. 6,309,125 to Andrea Peters discloses an adjustable mascara applicator that includes a brush attached to a bendable wand which is characterized by recovery memory in which it automatically assumes a predetermined bend angle in the absence of bending force.
While International Patent application WO 2007/117091A1 to Amorepacific Corporation, discloses an adjustable mascara brush that includes a brush stick provided in a cap, a brush provided at the end of the brush stick and an elevating bar which is connected to the brush stick in a manner of screw wherein the brush gets straightened when the elevating bar is lowered and the brush gets curved when the elevating bar is elevated up.
Although many of these prior art adjustable applicators are relevant with respect to the present invention, most of them use an additional component i.e. a rod that is either pre-bent or has a recovery memory. Moreover, none of the designs propose a mechanism by which the applicator element could be straightened or curved to varying degrees without the usage of additional component.
Therefore, there exists a need for an applicator that provides ease-of-use as well as is modifiable to adapt to the shape requirement of the user.
Further, there may also be a requirement by the user to lift and curl the eyelashes, which generally requires a different instrument such as a curler. However, it would be desirable that a single applicator is able to apply and lift and curl the lashes. Therefore, there is a need for an applicator that provides added function of lifting and curling the eyelashes.
SUMMARY
The present invention generally is an adjustable applicator employed for application of a cosmetic or a care product such as for application of mascara, coloring strands of hair, for dental flossing or for applying pharmaceuticals or cleaning agents. The use of adjustable applicator of the present invention for removal of make up products is also contemplated.
According to an embodiment of the invention, there is provided an applicator which employs an inventive mechanism to enable angular deformation of the applicator element to varying degrees of deformation.
In accordance with an embodiment of the invention, the adjustable applicator of the invention comprises of an applicator element and a filament. In the applicator element is provided a bore that houses the filament. Further, the filament is arranged to be movable inside the bore of the applicator element.
According to an embodiment of the invention the bore in the applicator element may be either centrally or non-centrally aligned.
According to yet another embodiment of the invention, the applicator element may be molded as a single piece from an elastically deformable material. The applicator element may be produced from an elastomer or any other elastic material allowing compression and expansion of the applicator element.
According to an embodiment of the invention, the filament may be made out of a material selected from a polymeric material and metals.
According to an embodiment of the invention, the filament is so arranged as to cause progressive modification in the shape of the applicator element. The filament facilitates adjustment of the angular deformation of the applicator element.
According to an embodiment of the invention the applicator element further comprises a biasing member arranged so as to assist the material memory of the applicator.
According to yet another embodiment of the invention, one end of the filament is connected to the distal end of the applicator element and the other end of the filament is attached to a clasping means such that when force is applied on the clasping means it causes tension along the axis of the filament which results in angular deformation of the applicator element. Further, the force applied to the clasping means is directly proportional to the deformation angle of the applicator element achieved. The filament may alternatively be connected by way of a locking arrangement with the distal end of the applicator element thereby guiding the movement of the applicator. For example, when the filament is in a stretched state it causes the applicator to be bent while when it is in relaxed state it guides the applicator to come back to its straight position.
According to an embodiment of the invention the clasping means may be provided at the proximal end of the filament itself. Alternatively, the filament may be engaged with another element having clasping or any other suitable means for application of force. Further, the mode of application of force on the clasping means could be manual, mechanical, magnetic, electrical or any other suitable mode.
According to an embodiment of the invention the applicator element may have a substantially circular outside cross-section, but the case in which the deformable applicator element has a cross-section of different shape, such as polygonal, is also contemplated by this invention.
According to yet another embodiment of the invention, the filament may be fixed tautly at both the ends of the applicator element such that the angular deformation in the applicator element is caused by application of force along the axis of the applicator.
Independently or in combination with the above, exemplary embodiments of the invention provide a device for packaging and dispensing a substance, for example, a cosmetic, comprising an applicator as defined above. The device may comprise a receptacle and an adjustable applicator. The adjustable applicator in such a device may comprise a gripping member, a stem having a cavity and an applicator element wherein the stem may be connected to the applicator element at one end and to the gripping member at another end. The said device may also include a wiper member. The gripping member may comprise a cap for closing the receptacle and a manipulating means for adjusting the angular deformation of the applicator element. The said manipulating means could be connected to a movable member present inside the cap in such a way that its rotational movement with respect to the cap is restricted while translational movement is allowed and said movable member is connected to the filament in the applicator element.
According to another embodiment of the invention the movable member of the packaging device may be connected to the filament via another filament that passes through the cavity inside the stem and hooks up the filament of the applicator. In such a case, the force provided by the manipulating means effects synchronous movement of both the filament in the stem as well as the filament in the applicator with respect to the gripping member thereby adjusting the angular deformation of the applicator element.
According to yet another embodiment of the invention, the adjustable applicator may comprise a stem connected to the applicator element at one end and a gripping member provided at another end of the stem. The stem may be hollow from inside. The gripping member may comprise a handle member and a manipulating means for adjusting the angular deformation of the applicator element. The said manipulating means could be connected to a movable member present inside the handle in such a way that its rotational movement with respect to the handle is restricted while translational movement is allowed and said movable member is directly connected to the filament that passes through the cavity in the stem to the applicator element. In a further embodiment, the movable member may also be connected to the filament via a separate filament that passes through the cavity inside the stem and hooks up the filament of the applicator member. In such a case, the force provided by the manipulating means effects synchronous movement of both the filament in the stem as well as the filament in the applicator with respect to the handle for adjusting the angular deformation of the applicator element.
According to an embodiment of the invention, there is provided an adjustable applicator wherein the user has more control over the curved angle achieved in the applicator. Further, a constant rigidity of the applicator is provided as no additional component is inserted or withdrawn to achieve the straight or curved shape.
According to another embodiment of the invention, the applicator element is capable of being used for application of a care product such as a dental floss or in a cosmetic product such as mascara. Further, the adjustable applicator could also be used for removal of a cosmetic product such as mascara.
According to yet another embodiment of the invention there is provided an applicator which employs an inventive mechanism to enable radially-angular deformation of the applicator element to varying degrees of deformation. The radially angular deformation being defined herein as the angular deformation occurring on the radial axis of the applicator element. Further, the deformation may be regular or irregular. Alternatively, the deformation in the applicator may follow a helical path.
According to yet another embodiment of the invention the adjustable applicator comprises an applicator element and a filament. In the applicator element is provided a bore that houses the filament such that the filament is arranged to be movable inside the bore of the applicator element. The bore in the applicator element may be either centrally or non-centrally aligned. The applicator element may be molded as a single piece from an elastically deformable material. The applicator element may be produced from an elastomer or any other elastic material allowing radially-angular deformation of the applicator element.
According to an embodiment of the invention, the filament may be made out of a material selected from a polymeric material and metals.
According to an embodiment of the invention, the filament is so arranged as to cause progressive modification in the shape of the applicator element, there occurs a progressive decrease or increase in the angle of deformation of the applicator element. The filament facilitates adjustment of the radially-angular deformation of the applicator element. The radially-angular deformation may be distributed evenly throughout the applicator element i.e. the angular gap is maintained evenly in the body of the applicator element. As an exemplary embodiment the radially-angular deformation in the applicator element may be such that there occurs twisting of the body of the applicator element. Alternatively, the angular deformation may be irregular or uneven in the body of the applicator element. When the applicator element is a mascara brush, the angular deformation in the applicator element helps in lifting and curling of the eyelashes.
According to an embodiment of the invention the applicator element further comprises a biasing member arranged so as to assist the material memory of the applicator.
According to yet another embodiment of the invention, one end of the filament is connected to the distal end of the applicator element and the other end of the filament is attached to a clasping means such that when force is applied on the clasping means it causes tension along the radial axis of the filament which results in angular deformation of the applicator element. Further, the force applied to the clasping means is directly proportional to the deformation angle of the applicator element achieved. The filament may alternatively be connected by way of a locking arrangement with the distal end of the applicator element thereby guiding the movement of the applicator. For example, when the filament is in a stretched state it causes the applicator to be angularly deformed while when it is in relaxed state it guides the applicator to come back to its straight position.
According to an embodiment of the invention the clasping means may be provided at the proximal end of the filament itself. Alternatively, the filament may be engaged with another element having clasping or any other suitable means for application of force. Further, the mode of application of force on the clasping means could be manual, mechanical, magnetic, electrical or any other suitable mode.
According to an embodiment of the invention the applicator element may have a substantially circular outside cross-section, but the case in which the deformable applicator element has a cross-section of different shape, such as polygonal, is also contemplated by this invention.
According to yet another embodiment of the invention, the filament may be fixed tautly at both the ends of the applicator element such that the angular deformation in the applicator element is caused by application of force along the axis of the applicator.
Independently or in combination with the above, exemplary embodiments of the invention provide a device for packaging and dispensing a substance, for example, a cosmetic, comprising an applicator as defined above. The device may comprise a receptacle and an adjustable applicator. The adjustable applicator in such a device may comprise a gripping member, a stem having a cavity and an applicator element wherein the stem may be connected to the applicator element at one end and to the gripping member at another end. The said device may also include a wiper member. The gripping member may comprise a cap for closing the receptacle and a manipulating means for adjusting the angular deformation of the applicator element. The said manipulating means could be connected to an inner rod present inside the cap in such a way that its rotational movement with respect to the cap is allowed and said inner rod is further connected to the filament in the applicator element.
According to yet another embodiment of the invention, the adjustable applicator may comprise a stem connected to the applicator element at one end and a gripping member provided at another end of the stem. The stem may be hollow from inside. The gripping member may comprise a handle member and a manipulating means for adjusting the angular deformation of the applicator element. The said manipulating means could be connected to an inner rod present inside the handle in such a way that its rotational movement with respect to the handle is allowed and said inner rod may be in the form of a filament that passes through the cavity in the stem and connects to the applicator element. In a further embodiment, the inner rod may be connected to the applicator filament and hooks up the filament of the applicator member. In such a case, the force provided by the manipulating means effects synchronous movement of both the inner rod in the stem as well as the filament in the applicator with respect to the handle for adjusting the angular deformation of the applicator element.
According to an embodiment of the invention, there is provided an adjustable applicator wherein the user has more control over the angular deformation achieved in the applicator. Further, a constant rigidity of the applicator is provided as no additional component is inserted or withdrawn to achieve the straight or angularly deformed shape.
These and further aspects which will be apparent to the expert of the art are attained by an adjustable applicator in accordance with the main claim.
BRIEF DESCRIPTION OF THE DRAWINGS
So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
FIG. 1 illustrates an isometric view of the applicator according to an embodiment of the invention;
FIG. 2 is a cross sectional view of the applicator taken along the line A-A of FIG. 1
FIG. 3 is a cross sectional view of the applicator in curved position taken along the line A-A of FIG. 1 ;
FIG. 4 illustrates an isometric view of the device comprising the adjustable applicator according to one embodiment of the present invention;
FIG. 5 illustrates an exploded view of the device comprising the adjustable applicator according to one embodiment of the present invention;
FIG. 6 is an isometric view of the adjustable applicator according to one embodiment of the present invention;
FIG. 7 is cross sectional view of the device comprising the adjustable applicator taken along the line B-B of FIG. 3 ;
FIG. 8 is cross sectional view of the adjustable applicator according to one embodiment of the present invention taken along the line A-A of FIG. 3 ;
FIG. 9 is cross sectional view of the adjustable applicator in curved position according to one embodiment of the present invention taken along the line A-A of FIG. 3 ;
FIG. 10 is an isometric view of an adjustable applicator according to another embodiment of the present invention;
FIG. 11 is an isometric view of the device containing the adjustable applicator of FIG. 10 ;
FIG. 12 represents a cross-sectional view of the adjustable applicator of FIG. 10 ;
FIG. 13 represents a cross-sectional view of the device of FIG. 11 ;
FIG. 14 a illustrates the isometric views of the adjustable applicator of FIG. 10 ;
FIG. 14 b is an isometric view of the adjustable applicator of FIG. 10 showing the applicator as seen upon 180 degree radially-angular deformation;
FIG. 14 c is an isometric view of the adjustable applicator of FIG. 10 showing the applicator as seen upon 360 degree radially-angular deformation;
FIG. 15 a is a front view of the adjustable applicator of FIG. 10 ;
FIG. 15 b is a front view of the adjustable applicator of FIG. 10 showing the applicator as seen upon 180 degree radially-angular deformation;
FIG. 15 c is an isometric view of the adjustable applicator of FIG. 10 showing the applicator as seen upon 360 degree radially-angular deformation;
FIG. 16 a is a top view of the adjustable applicator of FIG. 10 ;
FIG. 16 b is a top view of the adjustable applicator of FIG. 10 showing the applicator as seen upon 180 degree radially-angular deformation;
FIG. 16 c is a top view of the adjustable applicator of FIG. 10 showing the applicator as seen upon 360 degree radially-angular deformation;
FIG. 17 a is an isometric view of an adjustable applicator according to another embodiment of the invention;
FIG. 17 b is an isometric view of the adjustable applicator of FIG. 17 a showing the applicator as seen upon 180 degree radially-angular deformation;
FIG. 17 c is an isometric view of the adjustable applicator of FIG. 17 a showing the applicator as seen upon 360 degree radially-angular deformation;
FIG. 18 a is a front view of the adjustable applicator of FIG. 17 a;
FIG. 18 b is a front view of the adjustable applicator of FIG. 17 a showing the applicator as seen upon 180 degree radially-angular deformation;
FIG. 18 c is an isometric view of the adjustable applicator of FIG. 17 a showing the applicator as seen upon 360 degree radially-angular deformation;
FIG. 19 a is a top view of the adjustable applicator of FIG. 17 a;
FIG. 19 b is a top view of the adjustable applicator of FIG. 17 a showing the applicator as seen upon 180 degree radially-angular deformation;
FIG. 19 c is a top view of the adjustable applicator of FIG. 17 a showing the applicator as seen upon 360 degree radially-angular deformation;
To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
DETAILED DESCRIPTION
The adjustable applicator according to one embodiment of the present invention is shown in FIGS. 1 to 3 .
FIG. 1 is one embodiment of the present invention showing the adjustable applicator 100 . The adjustable applicator 100 of the invention comprises of an applicator element 101 and a filament 102 . In the applicator element 101 is a bore 104 housing the filament 102 . The bore 104 may either be centrally or non-centrally aligned. The filament 102 is arranged to be movable inside the bore 104 of the applicator element 101 . The applicator element 101 may be produced from an elastomer or any other elastic material allowing compression and expansion of the applicator. Further, the filament 102 may be made out of a material selected from a polymeric material and metals. The filament 102 is so arranged as to cause progressive angular deformation of the applicator element 101 .
As shown in FIGS. 2 and 3 , one end of the filament 102 is connected at a distal end 103 of the applicator 100 and the other end of the filament 102 is attached to a clasping means 105 such that when force is applied on the clasping means 105 it causes tension along the axis of the filament 102 , which results in angular deformation of the applicator element 101 as is illustrated in FIG. 3 . Further, the force applied on the filament 102 is directly proportional to the deformation angle of the applicator element 101 achieved. The mode of application of force on the clasping means 105 could be manual, mechanical, magnetic, electrical or any other suitable mode to cause tension along the axis of the filament 102 . Moreover, the applicator element 101 may have a substantially circular outside cross-section, but the case in which the deformable applicator element 101 has a cross-section of different shape, such as polygonal, is also contemplated by this invention. Further, the applicator element may further comprise of a biasing member arranged so as to assist the material memory of the applicator element.
A device 200 for packaging and dispensing a substance comprising the said applicator is illustrated by FIGS. 4 and 5 . The device 200 comprises a gripping means 201 and a receptacle 202 containing the substance. As shown in FIG. 6 , the gripping means 201 further comprises a handle 203 , a stem 204 and an applicator 205 . The proximal end of the stem 204 is connected to the handle 203 while its distal end is connected to the applicator 205 . The handle 203 acts as a manipulating means for adjusting the deformation of the applicator 205 . The handle 203 further comprises a cap 206 and a casing 207 that houses a movable member 208 . FIGS. 6 to 8 illustrate the gripping means 201 in further details and the arrangement of various parts of the device 200 . As shown in FIGS. 7 to 9 , one end of the casing 207 has ledges 209 which mate with complimentary ledges 210 in the cap 206 , thereby restricting movement of the cap 206 along its longitudinal axis and at the same time allowing rotational movement of the cap 206 with respect to the casing 207 . However, any lock and key arrangement between the casing and cap could be used for restricting axial movement of the cap with respect to the casing. The movable member 208 is hollow from inside and is so arranged with the cap 206 that its rotational movement with respect to the cap 206 is restricted. The casing 207 has threads 216 in its inner surface just above its centre towards its proximal end that mate with the threads in the movable member 208 , thereby allowing movement of the movable member 208 along its axis. Further, below the centre point of casing 207 is present an annular ridge 217 through which it cooperates with the stem 204 . Also present are threads 219 at distal end of the casing 207 which cooperate with the threads 220 in the neck of the receptacle 202 helping in fastening and unfastening of the gripping member 201 with respect to the receptacle 202 . The stem 204 houses a separate filament 213 . However, there may be present one filament that extends through the stem and the applicator element. At the proximal end of the movable member 208 is provided a feature for example a groove 212 to hold one end of the filament 213 . The filament 213 has a groove 214 at its distal end which engages the applicator filament 215 . The applicator 205 is hollow from inside and houses the applicator filament 215 . Also, one end of the applicator filament 215 is fitted inside the applicator 205 . The applicator filament 215 is adjusted with the groove 214 such that it is off-centered and provides a favorable and consistent plane along which angular deformation of the applicator occurs. However, the groove 214 may also be centrally aligned. Further, in such an arrangement, the force exerted via the gripping means 201 effects synchronous movement of both the filament 213 in the stem as well as the applicator filament 215 with respect to the applicator 205 to cause the desired angular deformation of the applicator 205 . The said device 200 may also include a wiper member 218 .
FIG. 9 illustrates the applicator 205 in its angularly deformed state. The rotation of the cap 206 with respect to the casing 207 results in the axial displacement of the movable member 208 thereby displacing the filament 213 and the applicator filament 215 along with it. The displacement in the applicator filament 215 causes the applicator 205 to angularly deform.
During use, the user rotates the cap 206 with respect to the casing 207 of the gripping means to cause the applicator 205 to be suitably deformed along a desired axis. Also, the user can control the magnitude of deformation during use.
FIG. 10 is another embodiment of the present invention showing a device 350 containing an adjustable applicator 300 . The device 350 for packaging and dispensing a substance comprising the said adjustable applicator 300 is illustrated by FIGS. 11 to 13 . The device 350 comprises a gripping means 301 and a receptacle 302 containing the substance. As shown in FIGS. 10 to 13 , the gripping means 301 further comprises a handle 303 , a stem 304 and an applicator element 305 . In the applicator element 305 is a bore housing an applicator filament 306 . The bore may either be centrally or non-centrally aligned. The applicator filament 306 is arranged to be movable inside the bore of the applicator element 305 . The applicator element 305 may comprise of bristles, discs or flocked applicator element or any suitable applicator suitable for cosmetic use. Further, the applicator element 305 may be produced from an elastomer or any other elastic material allowing compression and expansion of the applicator. Further, the applicator filament 306 may be made out of a material selected from a polymeric material and metals. The applicator filament 306 is so arranged as to cause progressive angular deformation of the applicator element 305 . Further, the applicator element 305 may house a biasing means. Furthermore, the proximal end of the stem 304 is connected to the handle 303 while its distal end is connected to the applicator element 305 . The handle 303 acts as a manipulating means for adjusting the angular deformation of the applicator element 305 . As shown in FIGS. 11 to 13 , the handle 303 of the gripping member 301 further comprises an actuator means 303 a which causes the radially-angular deformation in the applicator element 305 . The radially-angular deformation being defined herein as the angular deformation occurring on the radial axis of the applicator element. The handle 303 further houses an inner rod 307 such that the inner rod 307 is connected to the actuating means 303 a . As seen in FIG. 11 , the protrusion in the proximal end of the inner rod 307 sits inside the hollow of the actuating means 303 a while the distal end of the inner rod 307 is engaged with the applicator filament 306 . Further, the inner rod 307 is encased in the stem 304 of the gripping means 301 . Further, the applicator element 305 has a free end 305 a and a fixed end 305 b such that the fixed end 305 b is fixed to the stem 304 of the gripping means 301 . As shown in the drawings the applicator filament 306 is housed in the applicator element 305 while the inner rod 307 is housed in the stem 304 , however, there may be present one filament that extends through the stem and the applicator element. The distal end of the inner rod 307 is provided a feature for example a groove to hold one end of the applicator filament 306 . The applicator element 305 is hollow from inside and houses the applicator filament 306 . Also, one end of the applicator filament 306 is fitted inside the applicator element 305 . The bore inside the applicator element 305 provides a favorable and consistent plane along which angular deformation of the applicator element 305 occurs. Further, in such an arrangement, the force exerted via the gripping means 301 effects synchronous movement of both the inner rod 307 in the stem 304 as well as the applicator filament 306 with respect to the applicator element 305 to cause the desired angular deformation of the applicator element 305 . The said device 350 may also include a wiper member 308 . Also present are threads at distal end of the handle 303 which cooperate with the threads in the neck of the receptacle 302 helping in fastening and unfastening of the gripping member 301 with respect to the receptacle 302 .
During use, the user rotates the actuating means 303 a with respect to the handle 303 of the gripping means 301 to cause the applicator 305 to be suitably angularly deformed at a desired degree. Also, the user can control the magnitude or degree of angular deformation during use.
FIGS. 14 a , 14 b and 14 c illustrate the isometric view of the applicator 305 in its normal state, deformed state with an angular deformation of 180 degrees and deformed state with angular deformation of 360 degrees respectively. The rotation of the actuating means 303 a with respect to the handle 303 results in the synchronous rotation of the inner rod 307 thereby angularly deforming the applicator filament 306 which inn turn causes the applicator 305 to angularly deform. The degree of angular deformation of the applicator filament 306 and hence the applicator 305 depends on the similar force applied to the actuating means 303 a . As an exemplary embodiment, when the actuating means 303 a is rotated to a less extent, the degree of angular deformation is less in the applicator 305 and if the degree of rotation is high then the degree of angular deformation is higher in the applicator. As represented by FIG. 14 b , the degree of angular deformation in the applicator 305 is 180 degrees while in FIG. 14 c , the degree of deformation of applicator 305 is 360 degrees.
FIGS. 15 a , 15 b and 15 c illustrate the front view of the applicator 305 in its normal state, deformed state with an angular deformation of 180 degrees and deformed state with angular deformation of 360 degrees respectively. While FIGS. 16 a , 16 b and 16 c illustrate the top view of the applicator 305 in its normal state, deformed state with an angular deformation of 180 degrees and deformed state with angular deformation of 360 degrees respectively.
As an exemplary embodiment of the invention, the applicator element 305 may comprise of bristles. FIGS. 17 a , 17 b and 17 c illustrate the isometric view of the applicator 405 in its normal state, deformed state with an angular deformation of 180 degrees and deformed state with angular deformation of 360 degrees respectively. FIGS. 18 a , 18 b and 18 c illustrate the front view of the applicator 405 in its normal state, deformed state with an angular deformation of 180 degrees and deformed state with angular deformation of 360 degrees respectively. While FIGS. 19 a , 19 b and 19 c illustrate the top view of the applicator 405 in its normal state, deformed state with an angular deformation of 180 degrees and deformed state with angular deformation of 360 degrees respectively.
The materials suitable for forming the receptacle 202 , 302 and the filament 213 could be polyprolpylene while the cap 203 , the casing 207 , the movable member 208 , the actuating means 303 a and the inner rod 307 could be formed of acrylonitrile butadiene styrene or any other suitable polymeric material. The material of applicator filament 215 , 306 could be any polymeric material as nylon or could be a suitable metal. The stem 204 , 304 may be formed of polyacetal or any other suitable polymeric material. The material for forming wiper 216 , 308 could be low-density polyethylene. The aforementioned materials for forming various parts of the device of the present invention are an example, however other suitable materials may also be used.
Depending upon the substance being used in the receptacle, a variety of sizes and shapes of the applicator can be utilized. The applicator 205 , 305 , 405 may be constructed of a porous or non-porous rubber, fabric mesh, felt material, foamed polymers, sponge material, Hydrel™, TPE or any other suitable material. Also, the applicator could have any suitable shape depending on the kind of application required. It could have a shape other than cylindrical such as ovular, tapered or any other suitable shape.
Although the above description and drawings show the device being cylindrical, the shapes and profile cross section thereof are not limited to the same.
These and further aspects which will be apparent to the expert of the art are attained by an adjustable applicator in accordance with the main claim.
While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow. | The present invention generally is an adjustable applicator employed for application of a cosmetic or a care product such as for application of mascara, coloring strands of hair, for dental flossing or for applying pharmaceuticals or cleaning agents. The invention discloses an adjustable applicator comprising an applicator element having a bore, a filament wherein the filament is housed inside the bore of the applicator element and a clasping means wherein the applicator element angularly deforms when a force is applied on the clasping means such that the angular deformation occurs on the radial axis of the applicator element. Also disclosed is a device for packaging and dispensing a substance comprising said adjustable applicator. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the field of antiglare coatings in general, and in particular, to coating compositions, methods for preparing coating compositions and methods for applying coating compositions to optical glass surfaces. The invention is particularly directed to reducing specular reflection on the surfaces of cathode ray tubes, for example, computer monitor screens, television tubes, etc.
2. Description of Prior Art
Specular reflection or glare is defined as the direct reflection of ambient light from a smooth glass surface. Images on the screens of cathode ray tubes, for example television tubes, are formed behind the glass screen of the tube. Natural and artificial sources of light are reflected from the otherwise smooth glass surface of such screens, interfering with the images formed behind the glass surface. A strong source of sunlight, for example through an unshaded window, is likely to substantially wash out the entire picture. A local light source, for example a lamp, will tend to have its image reflected from the screen, superimposed on the image formed by the cathode ray tube (CRT). This creates a very disturbing local distortion.
Coatings have been applied to the surfaces of television tubes with a controlled roughness or surface pattern so that ambient light is scattered and diffused, thereby reducing glare. The roughness should not unduly degrade the resolution of the images to be viewed. A very practical consideration for coatings applied to CRT screens is that the glare-reducing coating should adhere to the glass surface, and should be sufficiently hard to resist abrasion and chemically resistant to moisture, humidity and common household cleaning solutions.
It is known in the art to reduce specular reflection with a vitrified, droplet pattern coating. Typically, an aqueous solution of an alkali silicate is sprayed in droplet form on a glass surface. The droplet pattern coating is dried and baked at an elevated temperature to provide a vitrified or glassy coating of corresponding pattern and surface contour. It is desirable to reduce the soda content in the vitrified coatings formed from such solutions in order to impart long-term stability against development of "bloom" on the coating surface. Such a solution is discussed in U.S. Pat. No. 3,114,668, which further teaches that picture or image resolution can be improved by incorporating a minor addition of boric oxide in the alkali silicate coating. Boric acid seemed to reduce the incidence of sharp-sided craters in the coating surface.
Another glare reducing coating is disclosed in U.S. Pat. No. 3,635,751, and is prepared by a method comprising the steps of: warming the surface of the glass screen to about 30° C. to about 100° C.; coating the warmed surface with an aqueous solution containing about 1 to 10 weight percent of a lithium-stabilized silica sol; drying the coating; and, heating the dry coating at about 150° C. to 450° C.
An improvement to the lithium silicate coating method is described in U.S. Pat. No. 3,940,511. It was observed that glare-reducing lithium silicate coatings on cathode ray tube face plates developed objectionable haze or "bloom" upon standing or storage at normal ambient humidities and temperatures. The haze is objectionable esthetically and reduces the brightness and color fidelity of the transmitted image. A similar haze was observed for sodium and potassium silicate coatings that have been baked at temperatures of about 400° C. to about 500° C. It was further observed that some glare-reducing lithium-silicate coatings which contained light attenuating particles transmitted an image which appeared to have a brownish or other tint. In the method according to the improvement, the dry baked coating is washed or rinsed with hot water subsequent to the baking step. Washing the coating with hot water reduces or eliminates the tendency of the coating to form a haze or bloom. The washing was believed to remove soluble lithium compounds which were present in the coating. In order to correct for any tint in the transmitted image which might be imparted by the glare-reducing coating, the coating might also include a small amount of a color-correcting dye.
Glare-reducing coatings are also of interest in applications other than glass screens, for example, on the surfaces of semiconductor solar cells. The object of anti-reflective coatings in this application is to promote transmission of, and to prevent reflection back into the atmosphere of solar radiation. Proper coatings can reduce the amount of light reflected when applied in thicknesses of one quarter of a wave length. Such coatings, as described in U.S. Pat. No. 4,361,598, can be made from clear solutions which contain oxide constituents in a soluble polymerized form and from which uniform and continuous glass-like oxide films can be deposited on substrates at relatively low temperatures. Such a solution is prepared by reacting metal alkoxide with a mixture of critical amounts of water and/or acid in an alcohol diluted medium. Alkoxides may be Ti(OR) 4 or Ta(OR) 5 , or another metal alkoxide such as Si(OR) 4 in admixture with these alkoxides. Acids may be HCl or HNO 3 . Quarter wave inorganic optical coatings are deposited by applying the alkoxide solutions to a substrate and then heating the coating at a temperature above 350° C. Of course, glare reducing coatings for such solar cells must be bounded to a surface of silicon doped with germanium, for example, which can be expected to react differently than glass in bonding with surface coatings.
Image quality can be difficult to measure objectively, particularly in evaluating resolution and contrast. Specular reflection has been customarily measured in terms of gloss or glare, objectively, by a gloss meter. Specular reflection can also be measured subjectively in terms of lines per inch and correspondence to a standard pattern. A series of patterns, having different numbers of lines per inch can be projected onto a test panel and reflected to a viewer. The last pattern capable of being distinguished is a valve or measure of the specular reflection.
The coatings and methods described herein are effective for producing anti-glare coatings on optical glass screens. The degree of glare reduction by coatings according to this invention has been determined both objectively and subjectively to be every bit as effective as the best known coatings of the prior art, and at the same time, can be prepared and applied at a significant cost savings. Accordingly, anti-glare coatings according to this invention provide very significant advantages over the prior art.
SUMMARY OF THE INVENTION
It is an object of this invention to provide coatings for reducing specular reflection on optical glass screens.
It is another object of this invention to produce coatings for reducing specular reflection on optical glass screens at a significant cost reduction.
It is still a further object of this invention to provide coatings for reducing specular reflection on optical glass screens at substantial savings and the coatings are as effective as any known in the prior art.
It is yet another object of this invention to provide solutions from which such coatings can be made.
It is yet another object of this invention to provide methods by which such solutions can be applied to optical glass screens to form such anti-glare coatings.
Briefly, this invention embodies anti-glare coatings for optical glass screens and the like and methods for preparing and applying such coatings, which are considerably less expensive than has been known in the art. Despite the savings in cost, the coating is just as effective in reducing specular reflection on optical glass screens as any coating now available.
In the presently preferred embodiment, an anti-glare coating according to this invention comprises a partially hydrolized metal alkoxide polymer. These metal alkoxides have the general formula M(OR) 4 where M is selected from the group consisting of silicon, titanium and zirconium, where R is alkyl with 1 to six carbon. The equivalent titanium and zirconium alkoxides form approximately 10% of the solids, by molar ratio, and approximately 15% of the solid, by weight. The coatings may be produced from a solution formed by creating a partially hydrolized tetraethyl orthosilicate or ethyl silicate 40 (TEOS) with metal alkoxides of titanium and zirconium in alcohol and water, nitric acid being used as a homogeneous catalyst. The solvent of the solution is alcohol, such as ethanol, propanol or higher alcohols. The higher alcohol yields a film or coating with less haze and less sensitivity to humidity. The presently preferred alcohol is 2-propanol. It has been noted that ethanol-based solutions will gel at room temperatures within a month and propanol-based solutions will not gel at room temperature. When ethanol-based solutions are stored at lower temperatures, time of gelation will be greatly extended. With regard to forming TiO 2 , suitable starting components include titanium isopropoxide (TPT) and titanium butoxide (TBT). TBT is preferred as it is less sensitive to humidity.
The glass screen or panel to be coated is first cleaned, if necessary, and then preheated to a temperature in the range of approximately 20° C. to 75° C., higher temperatures producing a more defined surface topology, and therefore a greater diffusion effect. After the solution is sprayed onto the screen or panel, the screen or panel is baked at a temperature in the range of approximately 500° C. to 550° C., for a time period in the range of five to twenty minutes.
With reference to the schematic illustration of FIG. 3, the panel and coating must be baked for a sufficient period of time, and at a sufficient temperature, to drive off the alcohol and water molecules from the coating. As a result, the coating becomes densified and transformed into a glossy material. At the same time, this material bonds to the glass surface through M-O-Si bonding. Temperatures below 500° C. are insufficient to stabilize the coating by driving off the solvent and water molecules. Temperatures in excess of 550° C. may damage or distort the glass panel. It has been found that baking the panel at a temperature of approximately 520° C. for approximately five minutes, or 500° C. for approximately twenty minutes, is sufficient to completely stabilize and bond the coating to the glass screen or panel.
BRIEF DESCRIPTION OF THE DRAWINGS
Aspects of this invention are illustrated in the drawings, wherein:
FIG. 1 is a section view of a panel to which an anti-glare coating according to this invention has been applied;
FIG. 2 is a block diagram illustrating a method according to this invention for applying an anti-glare coating to an optical glass screen or panel; and,
FIG. 3 is a diagrammatic illustration of the manner in which a film formed by an anti-glare coating according to this invention is stabilized and bonded to a glass surface by baking.
It will be appreciated that this invention is not limited to the precise arrangements, instrumentalities and methodology illustrated in the drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Anti-glare coatings have been applied to optical glass screens or panels in a textured, roughened, or otherwise patterned topology, as illustrated in FIG. 1, wherein an anti-glare film or coating 14 has been applied to the surface 12 of a glass screen or panel 10. As is apparent by the representative shape of the upper or exposed surface 16 of the film or coating 14, the topology or texture of the film is not smooth and flat, but is patterned in order to enhance diffusion of reflected light. Depending upon the particular angle of the surface 16, representative light rays B and C are reflected at different angles, diffusing the light and reflected image of the light source. Some rays of light will be incident at such an angle as to pass through the coating, as in light ray A, and thereafter be reflected by the surface 12 of glass screen or panel 10. Such light rays will be diffused relative to those light rays reflected at the surface 16, and will also be refracted to an extent which depends upon the index of refraction of the film or coating 14.
The particular topology of the coating is as already known in the art, and does not form a part of this invention in and of itself. Accordingly, the particular advantages and disadvantages of different surface topologies will not be discussed in detail. The nature of the invention is such that significant savings can be achieved by using coatings according to this invention to form whatever surface topology is desired. The gloss reading, as measured by a conventional gloss meter, such as a "Gardner" meter, will reflect the extent of the diffusion resulting from the patterned topology of the coating. The gloss reading will also be a function of the intensity of the reflected light. The intensity depends upon the refractive index of the coating and its absorption characteristics.
The basic steps according to this method for applying an anti-glare coating are illustrated in FIG. 2. The general scheme of applying the solution includes steps which are generally included in prior art methods, such as spraying the solution onto the panel and baking the panel and solution to stabilize the coating. Nevertheless, such basic steps are modified according to the particular coatings according to this invention, and the solutions from which they are formed. As a first step, one must insure that the surface to be coated is clean and free of contaminants which would prevent proper stabilization and bonding of the film to the glass screen or panel. Depending upon the production stage at which the coating is applied, a special cleaning step may or may not be necessary.
The clean glass screens or panels are preheated to a temperature in the range of approximately 20° C. to 75° C. Such higher temperatures produce a more defined topology of the surface 16 of the film or coating 14, thereby providing a greater diffusion effect.
After preheating, the solution from which the coating is formed is applied to the surface of the optical glass screen or panel. The solution is in effect a partially hydrolized metal alkoxide polymer, in which a proper proportion of metal alkoxides are dissolved. Although the coating may be applied in a number of ways, the presently preferred method is to spray on the solution with an air gun. Certain parameters in particular related to application by spraying will effect the coating. The principal parameters include the size and shape of the spraying head, the distance of the spraying gun from the surface of the panel during application, the amount of air pressure driving the spray gun, the number of coatings or passes over the panel by the spray gun and the liquid pressure of the solution delivered to the spray head and the relative speed of the travel between the spray gun and the panel. Higher liquid pressure or head, measured in inches, will produce films with less haze, but flatter topology. Bringing the spray gun closer to the surface of the panel produces the same effect as high liquid head. Increasing the air pressure driving the spray gun produces finer droplets and more diffusion, but the film tends to have more haze. The greater the number of passes, the thicker the film will be. The thicker the film, the greater the extent of glare reduction. However, if the film becomes too thick, it will be prone to cracking.
After the solution has been applied, the coating must be bonded and stabilized to the glass surface as shown in FIG. 3. This is accomplished by baking the panel and the solution applied thereto at a temperature in the range of approximately 500° C. to 550° C. for a sufficient amount of time to drive off the solvent and water in the solution, leavin a silica-titania-zirconia glass. The partially hydrolized metal alkoxides in the solution have the general formula [M(OR) 2-x (OH) x ] n as shown on the film side of the film/glass interface before baking. At the elevated baking temperature, the OR and OH group of the polymer bonds with the SiOH group of the glass surface, forming an alcohol and water. This alcohol and water is then evaporated from the coating. As a result, the coating becomes dense and chemically bonded to the glass surface. When the baking is complete, the solution has completely evaporated, leaving a silica titania-zirconia glass as the anti-glare coating. As set forth in FIG. 2, it has been found that baking at a temperature of approximately 520° C. for approximately five minutes is sufficient.
Six different formulations of solutions for forming coatings according to this invention were prepared and tested, the formulations being designated by Roman numerals I-VI. The ingredients of each formulation have been labeled by lower case letters to facilitate comparisons of the quantities of ingredients or components in the formulations.
Formulation No. I
(a) 101.8 ml of 2-propanol
(b) 37.0 gm TEOS
(c) 3.18 ml H 2 O+0.5 ml HNO 3
(d) 5.5 gm TPT (titanium isopropoxide; Ti(OC 3 H 7 ) 4 )
(e) 1.6 ml H 2 O+6.0 ml 2-propanol
Initially, the TEOS (b) was mixed into the 2-propanol (a), the mixture being then heated to a temperature of approximately 55° C. After heating, the water and nitric acid (c) were added and mixed during a period of approximately thirty minutes. Thereafter, the TPT (d) was added and mixed during a period of approximately fifteen minutes. Finally, the additional water and additional 2-propanol (e) were added and mixed during a period of approximately one and one half hours. At this point, the solution was ready for application to the glass screen or panel, preferably by spraying.
Each of the following formulations was prepared in the same fashion. Components or sets of components (a) and (b) were mixed and heated; (c) were added and mixed; (d) was (were) added and mixed; and, (e) were added and mixed.
Formulation No. II
(a) 80.0 gm 2-propanol
(b) 41.0 gm TEOS
(c) 3.55 ml H 2 O+0.7 ml HNO 3
(d) 3.36 gm TBT (titanium butoxide; Ti(OC 4 H 9 ) 4 )+3.63 gm zirconium n-propoxide (Zr(OC 3 H 7 ) 4 )
(e) 1.78 ml H 2 O+8.0 ml 2-propanol
Formulation No. III
(a) 101.8 ml 2-propanol
(b) 39.8 gm TEOS
(c) 3.2 ml H 2 O+0.5 ml HNO 3
(d) 6.72 gm TBT
(e) 1.6 ml H 2 O+6.0 ml 2-propanol
Formulation No. IV
(a) 80.0 gm 2-propanol
(b) 45.22 gm TEOS
(c) 3.91 ml H 2 O+0.7 ml HNO 3
(d) 6.72 gm TBT
(e) 1.95 gm H 2 O+6 ml 2-propanol
Formulation No. V
(a) 108.0 ml 2-propanol
(b) 41.07 gm TEOS
(c) 0.7 ml HNO 3 +3.55 ml H 2 O
(d) 5.76 gm TBT+0.93 gm Zr(OC 3 H 7 ) 4
(e) 1.78 ml H 2 O+6.0 ml 2-propanol
Formulation No. VI
(a) 110.0 ml 2-propanol
(b) 41.07 gm TEOS
(c) 0.7 ml HNO 3 +3.55 ml H 2 O
(d) 3.36 gm TBT+3.625 gm Zr(OC 3 H 7 ) 4
(e) 1.78 ml H 2 O+8.0 ml 2-propanol
EXAMPLE 1
Example 1 utilized formulation I, and was intended to demonstrate the effects of fluid pressure or head. During the first part of example 1 the distance from the spray gun to the float glass panel surface was 11 inches, the air pressure was 35 psig (pounds per square inch gauge) and the coating was formed from three passes of the spray gun. When the fluid pressure or head was 17.5 inches the gloss reading was 131; the prior reading was 154. When the fluid head or pressure was increased to 35 inches the gloss reading increased to 138.
In the second part of example 1 the distance of the spray gun to the panel was 11 inches, the air pressure was 45 psig and the coating was formed by six passes of the spray gun. When the fluid pressure was 17.5 inches, the gloss reading was 122. When the fluid pressure was raised to 35 inches the gloss reading remained 122.
EXAMPLE 2
Example 2 used formulation I and was intended to demonstrate the effect of the distance of the spray gun from the flow glass surface. During this test, the air pressure was 45 psig, the fluid pressure was 17.5 inches and the coating was formed by three passes of the spray gun. When the distance from the spray gun to the panel was 11 inches the gloss reading was 122. When the distance from the spray gun to the panel was increased to 12 inches the gloss reading increased to 141.
EXAMPLE 3
Example 3 utilized formulation II, and was intended to demonstrate the effect of the number of passes of the spray gun used to form the coating. In this test, the air pressure was 47 psig, the fluid pressure was 18.5 inches and the distance from the spray gun to the CRT screen panel was 113/4 inches. In the absence of any coating, the gloss reading was 88.5±3.6. When the coating was formed from three passes of the spray gun the gloss reading was 66.2±4. When the coating was formed from four passes of the spray gun the gloss reading was 61±3.7.
EXAMPLE 4
Example 4 utilized formulation II, and was intended to demonstrate the effect of preheating the optical glass screen or panel. In part 1 of this test the air pressure was 47 psig, the fluid pressure was 18 inches, the distance from the spray gun to the panel was 113/4 inches and the coating was applied by five passes of the spray gun. In the absence of any coating the gloss reading was 89.4±1.9. When the coating was applied after preheating the panel between 45° C. and 50° C. the gloss reading was 62.2±2.7. When the coating was applied after preheating the panel to 60° C. the gloss reading was 53±3.
In part 2 of this test the air pressure was 47 psig, the fluid pressure was 18.5 inches, the distance from the spray gun to the panel was 113/4 inches and the coating was applied by four passes of the spray gun. In the absence of a coating the gloss reading was 88.5±3.6. When the coating was applied after preheating the panel to a temperature between 58° C. and 60° C. the gloss reading was 61±3.7. When the solution was applied after preheating the panel to 67° C. the gloss reading was 60.8±4.1. When the coating was applied after preheating the panel to 77° C. the gloss reading was 58.5±3.3.
EXAMPLE 5
Parts 1 and 2 of this test utilized formulations III and IV respectively, and were intended to demonstrate the effect of a reduction in the amount of metal alkoxide. The parameters of this test were held constant for both parts 1 and 2, except as noted. In part 1 of this test the molar ratio of SiO 2 :TiO 2 was 9.65:1. The coating was applied by five passes of the spray gun. The gloss reading was 72.7±2.5.
In part 2 of this test, the molar ratio of SiO 2 :TiO 2 was increased to 11:1, while the thickness of the coating was reduced by applying the coating with only four passes of the spray gun. In this part the gloss reading was 65.4±2.2.
EXAMPLE 6
This test utilized formulation II, and was intended to demonstrate that additional coatings could be applied after an initial baking of prior coatings. During this test the air pressure was 47 psig, the fluid pressure was 18 inches and the distance from the spray gun to the panel was 113/4 inches. A first coating was applied by three passes of the spray gun and baked at a temperature of 520° C. for approximately seven minutes. The gloss reading was 70.5±3.1. Thereafter, more solution was applied by three additional passes of the spray gun, and once again the panel was heated to a temperature of approximately 520° C. for approximately seven minutes. The gloss reading after the second application was 64.8±3.
EXAMPLE 7
Parts 1 and 2 of this test were made with formulations V and VI respectively, and were intended to demonstrate that changing the ratio of TiO 2 to ZrO 2 did not significantly alter the gloss reading, although zirconium imparts better alkali resistance to the stabilized film than does titanium. In each of parts 1 and 2 the parameters were held constant. In each of parts 1 and 2 the solution included 0.2 moles of SiO 2 . In part 1 the molar ratio of TiO 2 :ZrO 2 was 5.67:1. The gloss reading was 74.5±2.5.
In part 2, the molar ratio of TiO 2 :ZrO 2 was 1:1. The gloss reading was 75.5±1.3.
On the basis of the tests conducted with the various formulations of solution noted herein, the best solution from which the form coatings according to this invention appears to be that of formulation II. Based upon the amounts of components listed, it can be shown that formulation II will result in a coating mixture comprising approximately 11.83 gm SiO 2 , approximately 0.79 gm TiO 2 and approximately 1.26 gm ZrO 2 . The TiO 2 and ZrO 2 therefore form approximately 15% of the solid, by weight. It can also be shown that the formulation results in approximately 0.197 moles of SiO 2 , 0.01 moles of TiO 2 and approximately 0.01 moles of ZrO 2 . Accordingly, the molar ratio of (TiO 2 +ZrO 2 ) is about 10% of the solids in the mixture (SiO 2 +TiO 2 +ZrO 2 ).
This invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. Accordingly, reference should be made to the appended claims, rather than to the foregoing specification, as indicating the scope of the invention. | A coating for reducing specular reflection on optical glass screens comprises a partially hydrolized metal alkoxide polymer. These alkoxides have the general formula M(OR) 4 where M is selected from the group consisting of silicon, titanium and zirconium where R is alkyl with 1 to 6 carbon. The equivalent titanium and/or zirconium oxides is about 15% of total solids by weight. A presently preferred coating mixture is prepared by dissolving tetraethyl orthosilicate in alcohol, at an elevated temperature; gradually adding a mixture of nitric acid and water; gradually adding titanium butoxide and/or zirconium n-propoxide; and, adding and mixing additional water and alcohol. The coating is applied by a method comprising the steps of cleaning the surface of the optical glass screen; preheating the glass screen; coating the solution onto the glass screen; and, baking the glass screen and solution, at a temperature high enough to drive off the solvent and bond the coating mixture to the glass surface. | 2 |
TECHNICAL FIELD
This invention relates to the field of carpet treatment, and particularly to a tool for restoring the appearance of carpet materials of which the pile has become flattened, by long storage in tight rolls for example.
BACKGROUND OF THE INVENTION
It is known by dealers in carpeting that carpet materials when stored under compression, as by shipment in tight rolls or by storage beneath other samples, suffer flattening of the fabric pile, and that simple release of the pressure is not always sufficient to restore the original appearance of the material.
It is also known that the exposing the pile surface to low pressure steam has a desirable effect, restoring the material to its original appearance. Apparatus for this purpose has been developed, and consist of a low pressure steam generator, a flexible hose, and a broad generally flat nozzle, by which the steam is distributed to a wide bank of the material being treated. The flat surface of the nozzle engaging the fabric sometimes acts as an ironer to lay the pile more flat instead of restoring it.
BRIEF SUMMARY OF THE INVENTION
We have found that if the steam dispensing nozzle is equipped with a blade member which not only prevents full flat contact of the nozzle with the material but also acts as a comb to stir the pile while the steam is being applied, the restoration is more complete and takes place more rapidly.
Various advantages and features of novelty which characterize the invention are pointed out with particularity in the claims annexed hereto and forming a part hereof. However, for a better understanding of the invention, its advantages, and objects obtained by it's use, reference should be had to the drawing which forms a further part hereof, and to the accompanying descriptive matter, in which there is illustrated an described a preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWING
In the drawing, in which like reference numerals indicate corresponding parts throughout the several views,
FIG. 1 is a view in perspective of a nozzle according to the invention;
FIG. 2 is a diagrammatic side view of the nozzle in use;
FIG. 3 is a view of the nozzle in section along the line 3--3 of FIG. 1;
FIG. 4 shows the nozzle attached to an elongated manipulating handle;
FIG. 5 shows the nozzle attached to a short manipulating handle;
FIG. 6 is a side view of a second embodiment of the invention;
FIG. 7 is a fragmentary sectional view of the nozzle of FIG. 6; and
FIG. 8 shows an embodiment in which the width of the steam outlet passage may be adjusted.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1-3 show a first embodiment of the invention to comprise an elongated hollow metal body 20 having closed ends 21 and 22 and a central inlet tap 23 for connection to a source of low pressure steam. Body 20 is formed with a generally flat lower surface 24, below which there projects, by a small distance D, a blade or lip 25 extending across the body. A steam dispensing slot 26 extends across the body between the forward edge of surface 24 and the rear of lip 25.
FIG. 5 shows that the nozzle tap 23 is connected to the flexible conduit 30 of a steam generator, not shown, by a rigid tube or handle 31 having a hand grip 32, and a steam diverting disc 33 for protecting the user's hand. For some applications, a longer handle 31 may be desirable, as shown in FIG. 4, and may include a pair of hand grips 32.
FIG. 2 shows the nozzle in use. It is applied with surface 24 generally parallel to the pile 40 of the fabric being treated, and is moved back and forth in the direction of arrow 41. Steam is dispensed through slot 26 to the fabric, and lip 25 prevents flat contact of surface 24 with the fabric, and acts as a comb to stir the pile concurrently with the initial contact of the steam with the fabric.
Among the refinements which can be added to nozzles according to the invention is modification to make steam dispensing more uniform all across the nozzle: by making the slot 26 narrower at this point and broadening it toward the ends of the nozzle, more uniform steam dispensing is accomplished.
The nozzle of FIG. 1 is preferably formed of sheet metal. FIGS. 6 and 7 show that a conventional cast aluminum nozzle 50 may be modified to enable practice of the invention. The surface 51 of the nozzle normally engaging the surface is inwardly curved at 52, and has a row of apertures 53 through which steam is dispensed to the fabric from a handle 31. A lip or blade 54 is secured to body 53 as by fasteners 55, and projects below surface 51 to perform the combined functions described above when the nozzle is moved back and forth across the surface.
Uniform steam displacement can be obtained in this embodiment of the invention by varying the size of the apertures 53 so that they become smaller as the center of the nozzle is approached.
It is convenient to have body 20 configured so that when the nozzle is suspended any condensation in the body runs to tap 23 and then back to the steam generator. The angularity needed in body 20 for this purpose is so slight as not to be perceptible in FIG. 1.
It is also sometimes convenient to be able to restrict the width of the steam outlet passage. To this end, as shown in FIG. 8, a shutter 24a may be adjustably secured to the lower surface 24 of body 20 by fasteners 26 passing through slots 26a in the shutter to enable sliding of the shutter to a position in which it closes the steam outlet passage to a desired extent.
From the foregoing it will be evident that the invention comprises a method and apparatus for restoring the pile of carpeting and similar fabrics by treatment with low pressure steam concurrent with combing the materials to physically act on the pile fibers as the steam is applied.
Numerous characteristics and advantages of the invention have been set forth in the foregoing description, together with details of the structure and function of the invention, and the novel features thereof are pointed out in the appended claims. The disclosure, however, is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts, within the principle of the invention, to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed. | A carpet steaming tool comprising an elongated plenum having a flat steam dispensing surface and a blade member extending along the tool and projecting transversely beyond the dispensing surface to comb or stir a carpet pile while steam is being dispensed. | 0 |
FIELD OF THE INVENTION
The present invention relates to a method for coding a sequence of video pictures, comprising at least an analysis step, including a first converting sub-step for converting the current picture into a sequence of macroblocks followed by a first pass encoding sub-step, and a final coding step, including a similar second converting sub-step followed by a second pass encoding sub-step at the end of which an output coded video bitstream is generated which may be used, for instance, for coding a sequence of pictures according to an image coding standard such as MPEG-2. The invention also relates to a video coder for implementing said coding method.
BACKGROUND OF THE INVENTION
The goal of MPEG is to define a standard for digital compression of video (and audio) signals. The basic principles of this standard are described in the document “MPEG video coding: a tutorial introduction”, by S. R. Ely, BBC Research and Development Report, BBC-RD-1996/3. A first generation of video encoders used single-pass encoding. Nowadays, some encoders use at least dual-pass encoding. According to such an encoding mode, each picture is coded twice: a first pass, at the end of which no video stream is generated, allows to collect statistical results and to code with a better quality the same current picture during a second pass, at the end of which the output coded video stream is generated. A greater number of passes may be provided, as observed for instance in the video coder described in the document EP 0940042 (PHF98524), in which, according to FIG. 1, one or several analysis passes AP allow to adjust some coding parameters before implementing, after a prediction step PS, a final coding pass CP.
It is known that the MPEG-2 standard allows to code interlaced pictures, i.e. pictures composed of two interlaced fields. As described in the document EP 0603947 (PHF92570), said pictures can be encoded at the macroblock level according either to a frame encoding mode or to a field encoding one, on the basis of a predefined criterion. However, none of these two solutions is optimal: impairment of the displayed image quality and of the compression efficiency is observed when a picture sequence comprising a lot of motion is frame encoded or, on the contrary, when a quasi motionless sequence is field encoded.
SUMMARY OF THE INVENTION
It is therefore an object of the invention to propose an improved coding method with which the cited drawback is avoided.
To this end, the invention relates to a method such as defined in the introductive paragraph of the description and which is moreover characterized in that statistical results are derived from said first pass encoding sub-step, coding decisions being then provided to the second pass encoding sub-step according to predetermined criteria related to said statistical results and to the type of the current picture.
According to the proposed solution, the suitable statistics resulting from the first pass are now used to encode the current picture either in the frame mode if the sequence can be considered as quasi motionless or in the field mode, at the picture level, if a significant motion has been detected with respect to the previous picture (to encode in the field mode means that the picture is de-interlaced and that the two fields constituting this picture are encoded separately and sequentially). The interest of this feature is the following: when an I or a P picture is field encoded (the intra pictures -or I pictures- are coded without any reference to other pictures, the predictive pictures- or P pictures- are coded using motion-compensated prediction from a previous I or P picture), the compression efficiency is also enhanced: the second field can be predicted with reference to the first one, which leads to have less intra blocks to encode I pictures, and to observe a better coherence between the two fields in case of P pictures.
An other object of the invention is to propose a video coder for implementing said coding method.
To this end, the invention relates to a video coder for encoding digital signals corresponding to interlaced-field picture sequences in which each picture is divided into subpictures called macroblocks, comprising a first coding sub-system for carrying out a first coding step at the macroblock level and a second coding sub-system for carrying out a second coding step at the end of which an output coded bitstream is generated, characterized in that:
(A) said first sub-system comprises a first encoding channel, which channel comprises a series arrangement of a first section for compressing interlaced data and an encoding section, and, in parallel therewith, a second encoding channel, which channel comprises a series arrangement of a second section for compressing non-interlaced data and an encoding section, a first prediction channel on the basis of output signals of said first section and, in parallel therewith, a second prediction channel on the basis of output signals of said second section, said second section including at its input side a circuit for de-interlacing the fields and said second prediction channel including a circuit for re-interlacing the fields, a decision sub-assembly comprising means for comparing the output signals of the first and second encoding channels and means for counting the number of macroblocks coded in accordance with the field mode, a computation circuit for counting the number of macroblocks that have been predicted according to the field motion compensated mode, and a processor for receiving said macroblock numbers and storing also the average quantization steps of the current and last picture;
(B) said second sub-system comprises a third encoding channel, which channel comprises a series arrangement of a third section for compressing interlaced data and an encoding section, and, in parallel therewith, a fourth encoding channel, which channel comprises a series arrangement of a fourth section for compressing non-interlaced data and an encoding section, a third prediction channel on the basis of output signals of said first section and, in parallel therewith, a fourth prediction channel on the basis of output signals of said fourth section, said fourth section including at its input side a circuit for de-interlacing the fields and said fourth prediction channel including a circuit for re-interlacing the fields, a decision sub-assembly comprising means for comparing the output signals of the first and second encoding channels and means for selecting the prediction and encoding channels in accordance with the result of said comparison, and a selection stage comprising means for connecting the pictures to be coded to the input of said second sub-system either directly or via a circuit for suppressing the field interlacing, according to the value of an output flag delivered by the processor on the basis of statistical results constituted by its input signals.
BRIEF DESCRIPTION OF THE DRAWINGS
The particularities and advantages of the invention will now be explained with reference to the embodiment described hereinafter and considered in connection with the drawings, in which:
FIG. 1 illustrates very schematically a double pass video coder;
FIGS. 2 and 3, considered together, illustrate an embodiment of a video coder according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
With a conventional coder, sequences that are rather still are generally well encoded. This is no longer the case when trying to code more difficult sequences with a lot of motion, flashes, sequences with a lot of scene changes, and so on. According to the video coding method here proposed, if a constant quantization step is used to encode a picture, it becomes possible to determine if some part of this picture is more difficult to encode, or not. A first coding pass is therefore carried out with such a constant quantization step, and its result is a list of statistics related to existing coding modes. The main ones, in the present case, are:
NFEM=number of field encoded macroblocks
NFMCM=number of field motion compensated macroblocks
AQSCP=average quantization step of the current P picture
AQSLP=average quantization step of the last P picture.
After having studied several relevant picture sequences coded in the field mode and in the frame mode, it is here proposed to take the decision of using during the second coding pass the frame or the field mode on the basis of the picture quality after decoding, such as estimated according to the statistical results of the first coding pass.
As seen later, the criterion for that choice is also related to the picture type, I, P, or B (the bidirectional predictive pictures, or B pictures, are coded on the basis of both previous and following I or P pictures) for each picture type, if a condition (or a specific set of conditions) is (are) valid, then the picture is encoded according to the field mode in the second coding pass, while it will be encoded according to the frame mode in the opposite case (condition(s) not valid).
The video coder of FIGS. 2 and 3, provided for carrying out the coding method described above, comprises two coding sub-systems 200 and 300 corresponding respectively to the implementation of the first and second coding passes. These sub-systems are now described.
The sub-system 200 shown in FIG. 2, which is in charge of the first pass, comprises a first encoding channel 210 , receiving the digital signals to be encoded, and an associated first prediction channel 220 . The encoding channel 210 comprises a series arrangement of an orthogonal transform circuit 212 (a discrete cosine transform in this embodiment), a quantizing circuit 213 and a variable-length encoding circuit 214 . The prediction channel 220 , that receives the signals before encoding (quantized signals), comprises, at the output of the circuit 213 , a switch 256 followed by a series arrangement of an inverse quantizing circuit 221 and an inverse orthogonal transform circuit 222 (an inverse discrete cosine transform in the present case) ensuring the respective inverse transforms of those performed by the circuits 213 and 212 . The output signals of the circuit 222 are applied to a first input of an adder 223 whose output signal is stored in a picture memory 224 . The output signal of the memory 224 is applied to a motion compensation stage 260 which comprises a motion estimation circuit 261 and a motion compensation circuit 262 . A first input of the circuit 262 receives the output signal of the memory 224 and a second input receives that of the circuit 261 .
The circuit 261 receives the digital input signals of the sub-system 200 (pictures PS) and determines, for each macroblock of the current picture, a displacement vector which is representative of the motion of said macroblock with respect to the corresponding macroblock of a picture previously transmitted for encoding (this determination is known as block matching) and is applied to the second input of the motion compensation circuit 262 . The circuit 262 supplies a predicted macroblock whose difference with the preceding macroblock is determined in a subtracter 225 which is arranged upstream of the orthogonal transform circuit 212 . The predicted macroblock is also applied to a second input of the adder 223 . The first input of the subtracter 225 receives the output signal of a format conversion circuit 275 (i.e. each macroblock MB of the current picture) which itself receives the input signals (the pictures PS to be processed). The digital signals at the input of the circuit 212 are thus signals representing the prediction error, i.e. the difference between each original picture macroblock and the predicted macroblock which is deduced therefrom after the operations performed in the prediction channel 220 , between the input of the inverse quantizing circuit 221 and the output of the motion compensation circuit 262 .
The sub-system 200 of FIG. 2 also comprises a second encoding channel 230 , an associated second prediction channel 240 and a decision sub-assembly 250 . The second encoding channel 230 , arranged in parallel with the first encoding channel 210 , comprises, at the output of the subtracter 225 , a series arrangement of a circuit 231 for suppressing the field interlacing, a second orthogonal transform circuit 232 , a second quantizing circuit 233 and a second variable-length encoding circuit 234 . Similarly as the first channel 220 , the second prediction channel 240 associated with this encoding channel 230 comprises a switch 257 followed by a series arrangement of a second inverse quantizing circuit 241 , a second inverse orthogonal transform circuit 242 , a second adder 243 , a second picture memory 244 , the output of which is applied, in the motion compensation stage 260 , to a second motion compensation circuit 264 . The channel 240 also comprises, in series between the circuits 242 and 243 , a circuit 245 for re-interlacing fields. The output of the channel 240 , i.e. that of the circuit 264 , supplies a predicted macroblock whose difference with the preceding macroblock is determined in the subtracter 225 , and which is also applied to a second input of the adder 243 . The second circuits 232 , 233 , 234 , 241 , 242 , 243 , 244 , 264 are identical to the first circuits 212 , 213 , 214 , 221 , 222 , 223 , 224 , 262 respectively.
The decision sub-assembly 250 comprises a first counter 251 for counting the number of bits at the output of the encoding circuit 214 , a second counter 252 for counting the number of bits at the output of the encoding circuits 234 and a comparator 253 for comparing said two numbers and, according to the lower of these numbers, deciding to increase by one, or not, the content of a counter 254 of the number NFEM of macroblocks that have been coded according to the field mode.
Similarly, in each prediction channel 220 and 240 , the processing of a MAE (mean absolute error) is performed in a computation circuit, 226 or 246 , receiving on the one hand the output of the motion compensation circuit 262 or 264 and on the other hand the original macroblock MB available at the output of the format conversion circuit 275 . For each motion compensation type, the MAE is calculated for each macroblock in the following way: diff = ( ∑ i = 1 16 ∑ j = 1 16 ( Ori [ i ] [ j ] - Pred [ i ] [ j ] ) ) / 256 MAE = ∑ i = 1 16 ∑ j = 1 16 Ori [ i ] [ j ] - diff
where ori [i][j] is a pixel of the macroblock to be coded and Pred [i][j] is a pixel of the prediction MB. The motion compensation decision consists in determining the MAE which has the lowest value. If the lowest MAE has been determined with a field vector, then the number NFMCM of macroblocks that have been predicted according to the field motion compensated mode is incremented in a counter 255 .
The numbers NFEM and NFMCM are sent towards a digital signal processor 280 . The quantization steps chosen in the quantizing circuits 213 and 233 are also sent towards said processor, in order to determine and store the average quantization step AQSCP of each current P-picture and the average quantization step AQSLP of the last P-picture. The statistics thus determined during the first pass allow to decide either to encode the current picture in the frame mode if the sequence is quasi-motionless, which is indicated by the first position of a flag S 1 returned by the processor 280 on the basis of the obtained statistics, or, if a significant motion has been detected by comparison with the previous picture, which is indicated by the other position of said flag, to suppress the interlacing of the picture and to encode each field of this picture separately.
As indicated above, several relevant picture sequences have been encoded in both modes and then studied. This study has shown that the decision of using the frame or the field encoding structure may be the picture quality after encoding, that is correlated to the statistical results of the first pass, and may also depend on the picture type. For each picture type, if the criterion indicated in the table in valid, then the picture will be, during the second pass, encoded according to the field mode. It will be encoded according to the frame mode if the criterion is not valid. The table is the following
PICTURE TYPE
CRITERION
I
IF (m × NFEM) > (n × NMIP)
P
IF (m × NFEM) > (n × NMIP)
OR (m × NFMCM) > n, × NMIP
OR (r × AQSCP) > (q × AQSLP)
B
IF (m × NFEM) > (n × NMIP)
OR (m × NFMCM) > n × NMIP
with NMIP being the number of macroblocks in the picture. In a preferred embodiment of the invention, the values of m, n, r, q are 4 , 3 , 10 , 15 respectively.
The sub-system 300 shown in FIG. 3, which is in charge of the second pass, comprises a third encoding channel 310 and an associated third prediction channel 320 . The third encoding channel 310 comprises a series arrangement of an orthogonal transform circuit 312 (a discrete cosine transform), a quantizing circuit 313 , a variable-length encoding circuit 314 , a buffer memory 315 delivering the output signal S 3 of the coder, and a return connection 316 between this memory and a second input of the circuit 313 for adjusting the quantization step and the bitrate. The third prediction channel 320 , that receives the signal before encoding (quantized signals), comprises, at the output of the circuit 313 , a switch 356 followed by a series arrangement of an inverse quantizing circuit 321 and an inverse orthogonal transform circuit 322 (an inverse discrete cosine transform) ensuring the respective inverse transforms of those performed by the circuits 313 and 312 . The output signals of the circuit 322 are applied to a first input of an adder 323 whose output signal is stored in a picture memory 324 . The output signal of the memory 324 is applied to a motion compensation stage 360 which comprises a motion estimation circuit 361 and a motion compensation circuit 362 . A first input of the circuit 362 receives the output signal of the memory 324 and a second input receives that of the circuit 361 . The circuit 361 receives the digital input signals of the coder (pictures PS), via a selection stage ( 455 , 454 ) which is described hereinunder, and determines, for each picture macroblock, its displacement vector which is applied to the second input of the motion compensation circuit 362 . The circuit 362 supplies a predicted macroblock whose difference with the preceding macroblock is determined in a subtracter 325 which is arranged upstream of the orthogonal transform circuit 312 . The predicted macroblock is also applied to a second input of the adder 323 . The first input of the subtracter 325 receives the output signal of a format conversion circuit 375 which itself receives, via the selection stage ( 455 , 454 ), the input signals of the coder. The digital signals at the input of the circuit 312 are thus, as for the circuit 212 , signals representing the prediction error, i.e. the difference between each original picture macroblock and the predicted macroblock which is deduced therefrom after the operations performed in the prediction channel 320 , between the input of the inverse quantizing circuit 321 and the output of the motion compensation circuit 362 .
The sub-system 300 of FIG. 3 also comprises a fourth encoding channel 330 , an associated fourth prediction channel 340 and a decision sub-assembly 350 . The fourth encoding channel 330 , arranged in parallel with the third encoding channel 310 , comprises, at the output of the subtracter 325 , a series arrangement of a circuit 331 for suppressing the field interlacing, an orthogonal transform circuit 332 , a quantizing circuit 323 , a variable-length encoding circuit 334 , the buffer memory 315 and a return connection 336 between said memory and a second input of the circuit 333 for adjusting the quantization step and the bitrate. Similarly, as the third channel 320 , the fourth prediction channel 340 associated with this encoding channel 330 comprises a switch 357 followed by a series arrangement of inverse quantizing circuit 341 , an inverse orthogonal transform circuit 342 , an adder 343 , a picture memory 344 , the output of which is applied, in the motion compensation stage 360 , to a motion compensation circuit 364 . The channel 340 also comprises, in series between the circuits 342 and 343 , a circuit 345 for re-interlacing fields. The output of the channel 340 , i.e. that of the circuit 364 , supplies a predicted macroblock whose difference with the preceding macroblock is determined in the subtracter 325 , and which is also applied to a second input of the adder 343 . The circuits 332 . 333 , 334 , 341 , 342 , 343 , 344 , 364 are identical to the circuits 312 , 313 , 314 , 321 , 322 , 323 , 324 , 362 respectively.
The decision sub-assembly 350 comprises a first counter 351 for counting the number of bits at the output of the encoding circuit 314 , a second counter 352 for counting the number of bits at the output of the encoding circuit 334 , and a comparator 353 for comparing these two numbers. A second selection stage, controlled by the output signal of the comparator 353 , comprises a first switch 355 whose non-common terminals are connected to the outputs of the two encoding circuits 314 and 334 respectively, and whose common terminal is connected on the one hand to the input of the buffer memory 315 for applying the output signal of one of these circuits 314 and 324 to said buffer memory, and on the other hand to the first and second switches 356 and 357 for connecting or not connecting each prediction channel at the output of the quantizing circuit of the associated encoding channel. A signal S 2 (constituted by a single bit in this case) is supplied by the decision sub-assembly 350 so as to be applied, after transmission, to a decoding device (not described hereinafter, since it is out of the scope of the invention) and to indicate whether the lines of the macroblock under consideration have been de-interlaced or not.
The selection stage, provided at the input of the sub-system 300 carrying out the second pass, comprises a switch 455 whose common terminal receives the input signals of the coder (pictures PS) and whose non-common terminals are connected, for the first one, directly to the inputs of the format conversion circuit 375 and the motion estimation circuit 261 and, for the second one, to the same inputs of these two circuits 375 and 361 but via a circuit 454 for suppressing the field interlacing of the picture. The switch 455 is controlled by a flag constituted by the output signal S 1 of the processor 280 . If this flag S 1 0, i.e. corresponds to the situation according to which the picture sequence can be considered as quasi-motionless, the position of the switch 455 corresponds to the direct connection to the circuits 375 and 361 . Conversely, if the flag S 1 =1, i.e. corresponds to the situation in which a significant motion has been detected, the circuit 454 allows to suppress the interlacing of the pictures PS before these pictures are sent towards the circuits 375 and 361 . In the latter situation, as the pictures are no longer interlaced, the coding step will take place only in the coding branch 310 .
In another embodiment of the coder according to the invention, it is also possible to take into account the existing of the double pass encoding process for detecting scene changes and thus obtaining a further picture quality improvement. Indeed, if it is assumed that within a sequence the complexity of the pictures is more or less constant, depending on the picture type, it can be expected to detect scene changes within the input sequence by analyzing the results of encoding with a constant quantisation step. The restriction of this scene change detection is that it is applied to I and P pictures only, because of the reordering of the pictures.
The case of the detection onto P pictures will be first described. In order to apply the scene change detection operation on any P picture, a storing step of the past two P pictures is needed. The parameters of detection are the following:
NbIntra, the number of macroblocks intra encoded for the current picture.
NbIntraPrev, the number of macroblocks intra encoded in the first pass of the previous P picture;
NbIntraPrev 2 , the number of macroblocks intra encoded in the first pass of the ante previous P picture;
SumIntra=NbIntraPrev+NbIntraPrev 2 ;
NbBits, LastNbBits, the numbers of bits used in the first pass of current and previous P pictures;
X 1 p, LastX 1 p, the resulting complexity of the current P picture and the last P picture respectively, at the end of the first pass;
NbNomc, the number of macroblocks encoded without motion compensation;
Nbmc, the number of macroblocks encoded with motion compensation;
NbMb, the number of macroblocks in the picture.
It will also be noted that:
if M=1, the algorithm is not applied on the 2 P pictures following an I picture, to avoid too much I pictures and consequently an impairment of the image quality;
the algorithm is not applied on the P picture following an I picture in certain conditions
The algorithm is the following:
If (10*NbBits>=4*ThresBits*LastNbBits)
and
(10*X 1 p>=4*ThresX*LastX 1 p)
and
(10*NbNomc<7NbMb)
and
(10*Nbmc<7*NbMb)
there is a scene change
Else If (20*NbIntra>=Thres 1 *SumIntra) and (10*NbIntra>=4*NbMb)
there is a scene change
Else If (20*NbIntra>=Thres 2 *SumIntra) and (10*NbIntra>=35*NbMb)
there is a scene change
Else If (10*NbIntra>=9*NbMb
there is a scene change
Else If (10*NbBits>=ThresBits*LastNbBits)
and
(10*X 1 p>=ThresX*LastX 1 p)
and
(10*NbIntra>=4*NbMb)
there is a scene change
with
thres 1 =17
thres 2 =30
thresX=15
thresBits=20
(the definition of the thresholds, based on the study of several sequences, is empirical).
The case of the detection onto I pictures is now described. As a scene change on P picture is detected by referring to the results of previous P pictures, false detection could occur when consecutive P pictures are separated by an I picture. That is why it is needed to detect if a scene change has occurred onto the I picture or not. A scene change onto an I picture can easily be detected by studying the prediction modes (interpolated, forward, backward) of the previous B frames (that are coded just after the I picture). If there are very few interpolated predictions and if one of the forward or the backward prediction is far more used than the other on both B frames, it means that there is a scene change on one of these three images. Thus, if for the B picture(s) following an I picture (in the encoding order), one has:
(100 *Tt Bidir<15*NbMb) and (( Tt Forw>10 *Tt Back) or ( Tt Back>10 *Tt Forw))
in which:
TtBidir is the number of macroblocks encoded with a bidirectional prediction
TtForw is the number of macroblocks encoded with a forward prediction
TtBack is the number of macroblocks encoded with a backward prediction
then, there is a scene change detection on the I picture. The algorithm of scene cut detection will not be applied to the first P picture following the I picture, but, instead, for the first P picture following the I picture, the statistics of detection will be updated, as illustrated in this example where a scene change occurs on picture 9 :
Input order:
B5
B6
P7
B8
B9
I10
B11
B12
P13 . . .
Encoding order:
P7
B5
B6
I10
B8
B9
P13
B11
B12 . . .
In that case, it may be understood that, for the B 8 picture, the most of the predictions will refer to the picture P 7 . while for the B 9 picture they will make reference to the picture I 10 . This can be deduced from the statistical results derived from the first encoding pass. | The invention relates to a video coding method based on an adaptive frame/field encoding mode. In order to avoid an impairment of the image quality and of the compression efficiency when a video sequence comprises a lot of motion or on the contrary quasi-motionless images, an improved real time double pass encoding scheme is proposed: during the first pass, no video stream is generated, but statistical results are computed and then provided to the second pass in order to optimize during said second pass the bit rate allocation and the buffer management. This improved double pass encoding method leads to an increase of the compression efficiency of about 10%. | 7 |
This is a continuation, of application Ser. No. 07/707,613, filed May 30, 1991, now U.S. Pat. No. 5,599,422.
SUMMARY OF THE INVENTION
The present invention relates to the masking of a glazing panel that is installed into a frame prior to painting or some other treatment of the frame.
It is common practice to assemble frames, such as window frames, French doors or mirror frames at a central manufacturing location. As part of the assembly process, glazing panels are installed. The glazing panels can be made of any of several common materials such as panes of glass or plastic, mirror panes, and vinyl or wood panels.
The frame, with one or more glazing panels installed, is then delivered to an installation site where paint or some other treating substance is to be applied to match the surrounding decor. In most such installations, it is desired that the treating substance not be applied to the glazing panels.
In the past, painting, staining, or other chemical treatment of such frames, after glazing panels are installed, has been a laborious process requiring much handwork to prevent stray paint or other substances from adhering to the panels. It has been necessary to manually mask the panels, to unmask the panels, or to paint the frames very cautiously. When such steps have not been taken, it has been necessary to scrape the panels clear after treatment.
One approach to easing the painting of window frames has been to encase glass panes in shrink wrap plastic before they are installed in a frame. The shrink wrap plastic sheeting protects the panes while the window frames are being painted. But, in order to remove the plastic after painting, a worker must hand cut the boundaries of each sheet with a knife. And, after the cutting, a perimeter portion of each masking sheet remains trapped between the pane and frame. This residual strip of flexible plastic material is not secured by an adhesive and can work loose and/or deteriorate with time. This causes the pane to be loose within the frame. Because the presence of such residual shrink wrap material makes it is impossible to seal the panes in the frame, shrink wrap encased panes are inappropriate for use in exterior doors and windows. Such an exterior application of shrink wrapped panes would leave holes in the heat insulation barrier of a building.
The present invention comprises a system whereby one or both surfaces of glazing panels are protected by masking material during painting of their frames and during their transport and installation.
The masking material is applied to a center portion of a surface of a panel before it is installed in the frame, but a perimeter portion is left uncovered. When the frame is assembled, only the uncovered portion of the panel is received within the frame. This allows the masking material to be easily peeled away without cutting and without leaving any residue between the frame and the panel. And, because no masking material remains within the frame, gaps are avoided.
Accordingly, it is an object of this invention to ease the painting or other treatment of frames into which glazing panels have been installed.
A further object is to protect glazing panels from abrasion damage, such as scratching, prior to their ultimate installation.
This and other features, objects, and advantages of the invention will be apparent from the drawings and detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIGS. 1A-6A are schematic diagrams showing progressive steps for making and using a glazing assembly according to the present invention;
FIGS. 1B-6B are enlarged partial sectional views taken along lines 1B-6B--1B-6B respectively;
FIG. 7 is a partial plan view of a frame holding a glazing assembly of the type shown in FIG. 4;
FIG. 8 is a partial sectional view taken along line 8--8 of FIG. 7;
FIG. 9 is a partial sectional view taken along line 8--8 of FIG. 7 showing the frame and assembly after the masking material has been removed;
FIG. 10 is a partial sectional view which illustrates a prior art assembly for comparison with the assembly shown in FIG. 9;
FIG. 11 is an elevational schematic view of an apparatus according to the present invention for installing masking material on a glazing pane;
FIG. 12 is a top plan schematic view of the apparatus showing FIG. 11; and
FIG. 13 is a top plan schematic view of a second apparatus for installing masking material on a glazing pane.
DETAILED DESCRIPTION
FIGS. 1-6 illustrate a procedure for making a glazing assembly according to the present invention.
FIG. 1 shows a typical glazing panel that has been cut to the appropriate dimensions for future installation in a frame. The frame could be a true divided light window frame, French door, picture frame, mirror frame, or any similar frame which holds a panel or pane. The drawings show a glass pane 18, but the panel could be made of any sheet-like material such as plastic sheeting, mirrored glass, decorative vinyl sheeting, wood sheeting or the like.
The illustrated glazing pane 18 has a first planar surface 20, a second planar surface 21, and four edge surfaces. In a first step, bodies of masking material 22, 24 are respectively positioned on the surfaces 20, 21 of the pane 18. In the illustrated embodiment of FIG. 2, the bodies 22, 24 cover the entire areas of the surfaces 20, 21.
Next, strips of the masking material are removed from two margin regions 20a which extend along opposite edges of the surface 20. This leaves a body 22a of masking material as shown in FIG. 3A. The body 22a is of a lesser area than body 22. Strips are similarly removed from margin regions of the surface 21.
Next, strips of the masking material are removed from other marginal portions 20b of the surface 20 leaving a body 22b of masking materials that is of still smaller area as shown in FIG. 4. The marginal regions 20a and 20b are together referred to herein as a perimeter region of the surface 20. The remainder of the surface 20, which remainder is covered by the body 22b, is referred to herein as a central region 20c. Strips are similarly removed from the margin regions 21b of the surface 21; and the names of the regions of surface 21 are analogous to the names used when describing the regions of surface 20. In this manner, an uninstalled glazing assembly, as shown in FIG. 4, is completed.
FIG. 5 show the assembly of FIG. 4 after it is installed in a wooden frame that is sized and shaped to receive the pane. The frame includes a backing frame 26 and retainer moldings 28. It is at this stage, after the glazing pane 18 has been installed in the frame and while the bodies 22b, 24b of masking material are still in place, that the frame is painted or otherwise treated. The bodies 22b, 24b protect the central regions 20c, 21c of the surfaces 20, 21 while the frame is being painted. The central regions are substantially the entire areas of the surfaces 20, 21 that are not hidden by the frame.
After painting is complete, the bodies 22b, 24b are removed. For example, a worker grasps a corner portion 30 (FIG. 5A) of the body 22b and pulls it away, thus uncovering the central portion 20c of the surface 20. The result is the completed window assembly shown in FIG. 6.
FIGS. 7 and 8 show an enlarged view of an installed glazing assembly similar to that shown in FIG. 5. FIG. 9 shows a view of that installed glazing assembly, after painting of the frame and removal of the masking material, similar to the assembly shown in FIG. 6. These figures illustrate how the widths w 1 , w 2 of the perimeter portions 20b, 21b are not less than the distances d 1 , d 2 that the panel 18 will extend along facing surfaces 30b, 32b of the frame members 28, 26 when the panel 18 is installed.
Ideally, the corresponding widths and the distances, e.g., w 1 and d 1 , will be equal along each edge of the panel. However, to provide tolerance for manufacturing variations, one can choose a margin portion width, e.g., w 1 , which is slightly larger than the distance, e.g., d 1 , that the pane will extend into the frame. It is not necessary that the distances d 1 , d 2 be equal. And, the width of the perimeter region of the panel surfaces need not be the same along each edge of the panel. The system of the present invention will work regardless of the relative dimensions of the panel and the frame opening which receives the panel.
FIGS. 7-9 also show how the perimeter portions of the panel 18, such as portions 20b, 21b directly contact the facing surfaces 30b, 32b of the frame. This is unlike the situation of prior art devices, as shown in FIG. 10, wherein a residual body 36 of masking material is left between the pane surfaces and the facing surfaces of the frame after installation.
A preferred masking material for use according to this invention is a flexible sheet of transparent or translucent plastic material such as polymask brand sheeting manufactured by Sealed Air Corp. Other masking materials, such as paper, can be used. But, a degree of transparency is desireable so that any flaws in the panel can be seen through the masking material. If an opaque masking material is used, a flaw could be covered and thus remain undetected until after the panel had been installed and the frame painted. The material should be sufficiently impervious to paint, stain, and the like so as to be suitable as a masking material.
The masking material may be attached by means of an adhesive which releasably secures the material to the surface or by static cling. Any adhesive used to secure the masking material should be selected to favor adherence to the masking material so that, when the material is removed, no adhesive residue remains on the panel.
FIGS. 11 and 12 show an apparatus for continuously making glazing assemblies according to the steps shown in FIGS. 1-6. In the illustration of FIGS. 11 and 12, the panels 18 are glass panes which are supported on a conveyor rolls 40 which serve as a panel support. Panes move along a path from left to right in FIGS. 11-12. As the panes move, they first encounter a laminator 40 wherein bodies 22, 24 of masking material are delivered to the panes from supply rolls 44. An applicator mechanism, including pinch rolls 46, receives the sheets of masking material and applies them onto the surfaces of the panes 18.
One or more cutting mechanisms are provided to remove strips of the masking material from the perimeter regions of the panes. These cutting mechanisms can take a variety of forms. In FIGS. 11-12, a first cutting assembly 48 includes four circular scoring knives 50 which contact the passing panes. The knives 50 cut longitudinal score lines 52 in the bodies 22, 24 of masking material. A drive mechanism may be provided to rotate the knives 50 or the knives 50 can be mounted as idlers which are rotated by frictional contact with the passing panes. The edge strips produced by such cutting can be removed to expose side margins of the pane surfaces.
FIGS. 11-12 show a second cutter assembly 54 that is provided downstream from the first cutter assembly 48. The second cutting assembly comprises four scoring knives 56 mounted on a carriage 58. The carriage 58 is adapted to travel on rails 60 parallel to the path of the panes 18. As best seen in FIG. 12, the panes 18 move edge to edge with little or no space between adjacent panes. When a pane 18 reaches the second cutter assembly, the webs which comprise the bodies 22, 24 of masking material are cut so that the panes can be separated and the end margin portions 20b, 21b can be uncovered. This cutting is accomplished by means of the knives 56. As the facing edges 62, 64 of two panes travel to the point where they are aligned between two blades 56 as shown in FIGS. 11-12, the second cutter assembly is actuated. Thereafter, the carriage 58 moves longitudinally at the same rate as the panes while scoring knives 56 are moved across the panes from one side of the path as shown in solid lines in FIG. 12 to a position at the other side of the path as shown by broken lines in FIG. 12. As the scoring knives 56 move across the panes, they cut lateral score lines 66 into the sheets of masking material so that strips of the masking material sheets can be removed from marginal regions 20b, 21b of the surfaces 20, 21. Thereafter, the panes are ready to be removed from the line.
A variety of techniques can be used to remove the marginal strips of masking material which are provided by cutting the score lines 52, 66. The strips can easily be peeled off manually by a worker. Or, stripping heads (not shown) can be provided along the edges of the conveyor and/or on the carriage 58 to automatically contact and peel off the marginal strips of the web.
Numerous variations are possible in the manufacturing apparatus. For example, instead of the illustrated first cutter assembly 48, one or more knives could be located between the supply rolls 44 and the pinch rolls 46 to cut off an edge portion from one or both side edges of the masking material webs before the pinch rolls apply those webs to the panes 18. With this type of apparatus, one bypasses the step illustrated in FIG. 2. Instead, assemblies of the type shown in FIG. 3, with exposed side margins, are obtained as soon as the webs are applied to the panes.
Another way of bypassing the step shown in FIG. 2 is to use supply rolls 44 which contain webs of masking material which are manufactured to be of the desired width. Using such webs, it is unnecessary to cut off portions and thus unnecessary to use a first cutter assembly 48 either before or after the pinch rolls 46. The side margins of the surface remain uncovered when the webs are applied.
One can use different cutting assemblies than those shown in FIGS. 11-12. For example, the traveling carriage mechanism 58 can be eliminated by separating the panes and rotating them ninety degrees before they enter the second cutter assembly. Such an arrangement is shown in FIG. 13, wherein the reference numerals correspond to those appearing in FIG. 12, but are incremented by one hundred. In such an arrangement, the second cutter assembly 154 could include knives 156 that are similar to the knives 150 of the first cutter assembly 148.
Finally, it is possible to skip both the stages shown in FIGS. 2 and 3. This can be accomplished by adhering pre-cut bodies 22b and/or 24b to the pane 18. Such bodies are precut to appropriate size and shape and then positioned to cover the central region of one or both surfaces of each pane. Although ease of painting would be achieved, this method of attaching the bodies would be more difficult to automate.
While we have described and illustrated various embodiments of our inventions, it will be apparent to those skilled in the art that many changes and modifications may be made without departing from the invention in its broader aspects. For example, masking material need be applied to only one side of a panel if only one side of the frame is to be painted or otherwise treated after the panel is installed. Also, in the drawings, the bodies 22b, 24b cover the entire central regions 20c, 21c of the panel 18. This is usually the best and most convenient arrangement. However, for large panels, the bodies 20c, 21c would not necessarily have to cover the centermost region of the surfaces 20, 21. The appended claims are, therefore, intended to cover all such changes and modifications as followed in the true spirit and scope of the invention. | Glazing panels, such as window panes, are protected by sheets of masking material which cover central regions of the panel surfaces and which leave marginal regions uncovered. The masked panels are installed in frames which can thereafter be sanded or painted or otherwise chemically treated. Prior to and during such treatments, the surfaces of the panels are protected by the masking material. After all installation and treatment procedures are complete, the masking material is removed to expose the clean central regions of the panel surfaces. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a double-balanced mixer circuit used for mixing signals of different frequencies.
2. Description of Related Art
In a portable telephone, for example, a local oscillation frequency signal and an intermediate frequency signal are mixed in a mixer circuit to generate a radio frequency signal which is to be transmitted. Because mixing of signals having different frequencies is based on a non-linear characteristic, outputs from the mixer circuit include, in addition to the radio frequency signal obtained by mixing, the individual local oscillation frequency signal which is not mixed and the individual intermediate frequency signal which is not mixed. In order to suppress the individual local oscillation frequency signal and the individual intermediate frequency signal, a double-balanced mixer circuit is commonly used for the mixer circuit.
FIG. 1 shows a circuit diagram of a conventional double-balanced mixer circuit. The double-balanced mixer circuit comprises a differential amplifier circuit DFA1 which outputs a signal LO 1 of the same phase as the local oscillation frequency signal LO and a signal #LO 1 obtained by an 180° phase shift on the local oscillation frequency signal LO upon input of the local oscillation frequency signal LO (frequency LO), a differential amplifier circuit DFA2 which outputs a signal IF 1 of the same phase as the intermediate frequency signal IF (frequency IF) and a signal #IF 1 obtained by 180° phase shift on the intermediate frequency signal IF upon input of the intermediate frequency signal IF, and an analog multiplier circuit ALG which mixes the local oscillation frequency signal LO and the intermediate frequency signal IF upon input of the signals LO 1 and #LO 1 which are output from the differential amplifier circuit DFA1 and the signals IF 1 and #IF 1 which are output from the differential amplifier circuit DFA2.
In the differential amplifier circuit DFA1, a power supply V DD is grounded via ann series circuit of an FET (field effect transistor) 2 and a resistor R 1 , and is grounded via a series circuit of a resistor R 2 , an FET 3 and an FET 4. In parallel with the series circuit of the resistor R 2 and the FET 3, a series circuit of a resistor R 3 and a FET 5 is connected. The power supply V DD is further grounded via a series circuit of an FET 6 and a resistor R 4 , with a capacitor C 1 being connected in parallel with the resistor R 4 . The junction of the FET 2 and the resistor R 1 is connected to one terminal of the capacitor C 2 and to the gate of the FET 3. The local oscillation frequency signal LO is fed to the other terminal of the capacitor C 2 . The gate of the FET 5 is connected to the junction of the FET 6, the resistor R 4 and the capacitor C 1 . The signal LO 1 of the same phase as the local oscillation frequency signal LO is output from the junction of the resistor R 2 and the FET 3, and the signal #LO 1 of the phase being shifted from that of the local oscillation frequency signal LO by 180° is output from the junction of the resistor R 3 and the FET 5.
The differential amplifier circuit DFA2 is made in a similar constitution as that of the differential amplifier circuit DFA1, and identical components are assigned the same numerals. In the differential amplifier circuit DFA2, the intermediate frequency signal IF is supplied to other terminal of the capacitor C 2 . The signal IF 1 of the same phase as the intermediate frequency signal IF is output from the junction of the resistor R 2 and the FET 3, and a signal #IF 1 of the phase being shifted from that of the intermediate frequency signal IF by 180° is output from the junction of the resistor R 3 and the FET 5.
In the analog multiplier circuit ALG, a power source V CC is connected to one terminal of a current source 10 via a series circuit of a resistor R 10 (R 11 ), a transistor Q 1 (Q 4 ) and a transistor Q 5 (Q 6 ), with another terminal of the current source 10 being grounded. The junction of the resistor R 10 (R 11 ) and the transistor Q 1 (Q 4 ) is connected to the junction of the transistor Q 4 (Q 1 ) and the transistor Q 6 (Q 5 ) via the transistor Q 3 (Q 2 ). The bases of the transistors Q 2 and Q 3 are connected to each other and the bases of the transistors Q 1 and Q 4 are connected to each other. The radio frequency signal RF generated by mixing the local oscillation frequency signal LO and the intermediate frequency signal IF is output from the junction of the resistor R 11 , the transistor Q 2 and the transistor Q 4 .
On the other hand, the signal LO 1 (#LO 1 ) from the differential amplifier circuit DFA1 is inputted to the bases of the transistors Q 2 and Q 3 (Q 1 and Q 4 ), and the signal IF 1 (#IF 1 ) from the differential amplifier circuit DFA2 is inputted to the bases of the transistor Q 6 (Q 5 ).
The operation of the double-balanced mixer circuit will now be described below.
When the local oscillation frequency signal LO is inputted to the differential amplifier circuit DFA1, the signal LO 1 having the same phase as the local oscillation frequency LO and the signal #LO 1 having a phase 180° shifted from the local oscillation frequency LO are inputted from the differential amplifier circuit DFA1 to the analog multiplier circuit ALG. When the intermediate frequency signal IF is inputted to the differential amplifier circuit DFA2, the signal IF 1 having the same phase as the intermediate frequency signal IF and the signal #IF 1 having a phase 180° shifted from the intermediate frequency signal IF are inputted from the differential amplifier circuit DFA2 to the analog multiplier circuit ALG. Then the analog multiplier circuit ALG outputs the radio frequency signals RF having frequencies of LO+IF and LO-IF generated by mixing the local oscillation frequency signal LO and the intermediate frequency signal IF.
The signal LO 1 and the signal #LO 1 cancel each other, and the signal IF 1 and the signal #IF 1 cancel each other, so that the signals LO 1 , #LO 1 , IF 1 and #IF 1 are not output individually, thereby improving the S/N ratio of the radio frequency signal RF.
The phase of a signal to be mixed can also be shifted by changing the path length. And the required change in the path length decreases as the frequency becomes higher. Therefore the method of changing the path length is employed in applications with frequencies 10 GHz or higher, in consideration of the degree of circuit integration.
Such a circuit is also employed in which phase inverter circuits are employed for the differential amplifier circuits DFA1 and DFA2 for phase shift. FIG. 2 shows a circuit diagram of a phase inverter circuit. The power supply V DD is grounded via a circuit comprising a parallel connection of a series circuit of a resistor R 20 and a resistor R 21 , a series circuit of a resistor R 22 , an FET 10 and a resistor R 23 , a series circuit of an FET 11 and a resistor R 24 , and a series circuit of an FET 12 and a resistor R 25 .
The junction of the resistors R 20 and R 21 is connected to one terminal of a capacitor C 10 and to the gate of the FET 10, while the local oscillation frequency signal LO or the intermediate frequency signal IF is fed to the other terminal of the capacitor C 10 .
The junction of the resistor R 22 and the FET 10 is connected to the gate of the FET 12, and the junction of the FET 10 and the resistor R 23 is connected to the gate of the FET 11. The signal LO 1 having the same phase as that of the local oscillation frequency signal LO or the signal IF 1 having the same phase as that of the intermediate frequency signal IF is output from the junction of the FET 12 and the resistor R 25 via the capacitor C 11 . The signal #LO 1 having a phase being shifted by 180° from the local oscillation frequency signal LO or the signal #IF 1 having a phase being shifted by 180° from the intermediate frequency signal IF is output from the junction of the FET 11 and the resistor R 24 via the capacitor C 12 .
Also in the case where this phase inverter circuit is used, similarly to the case where the differential amplifier circuit is employed, the signal LO 1 of the same phase as the local oscillation frequency signal LO and the signal #LO 1 obtained by 180° phase shift from the local oscillation frequency signal LO are obtained from the phase inverter circuit upon input of the local oscillation frequency signal LO, and the signal IF 1 of the same phase as that of the intermediate frequency signal IF and the signal #IF 1 obtained by 180° phase shift from the intermediate frequency signal IF are obtained from the phase inverter circuit upon input of the intermediate frequency signal IF.
The conventional double-balanced mixer circuit as described above is capable of good double-balanced mixing operation with less signal attenuation. However, because the conventional double-balanced mixer circuit comprises the differential amplifier circuits or the phase inverter circuit employing a number of FETs and the analog multiplier circuit employing a number of transistors, it consumes a considerable amount of power, and is therefore not suitable for the application in a portable telephone which has a limitation in the power consumption. Because the differential amplifier circuit, the phase inverter circuit and the analog multiplier circuit employ cascaded FETs and transistors, a significant voltage drop occurs and it is difficult to drive the portable telephone by a low-voltage power source, for example a 3 V power source, which is required in the portable telephone.
Also because a portable telephone uses the radio frequency signal RF having a frequency of 1.9 GHz, a GaAs MESFET (Metal Semiconductor FET) which has excellent high-frequency characteristics is more suitable than transistors based on Si. However, a GaAs MESFET is likely to depart from the linear small signal operation region when a signal having voltage amplitude greater than a certain level (for example, 0.1 to 0.2 V or higher) is inputted to the gate thereof, making it impossible to obtain a linear output. Because the local oscillation frequency signal and the intermediate frequency signal commonly used in a portable telephone have voltage amplitude of 0.1 V or higher, in a differential amplifier circuit made by using GaAs MESFETs as described above, a gate of the GaAs MESFET receives an input voltage higher than the level which gives a linear output, and results in such a problem as the distortion of the phase-shifted signals.
SUMMARY OF THE INVENTION
The invention has been conceived to solve the problems described above, and has a major object of providing a double-balanced mixer circuit which consumes a small amount of power and is capable of using a low voltage power source, by reducing the number of FETs (or transistors) being used.
Another object of the invention is to provide a double-balanced mixer circuit which is capable of outputting the radio frequency signal which has a high S/N ratio by means of a circuit wherein no FET (or transistor) is used in the first phase shifter and the second phase shifter.
The double-balanced mixer circuit of the invention comprises two phase shifters outputting signals whose phases are different from each other by 180° and two dual gate FETs to which said signals are inputted.
The double-balanced mixer circuit of the invention has a first phase shifter which outputs a first signal having a phase lag of 90° from a first frequency signal and a second signal having a phase lead of 90° over the first frequency signal upon input of the first frequency signal, and a second phase shifter which outputs a third signal having a phase lag of 90° from a second frequency signal and a fourth signal having a phase lead of 90° over the second frequency signal upon input of the second frequency signal which has a frequency different from that of the first signal. The first signal and the third signal are inputted to a first dual gate circuit and are mixed in the first dual gate circuit. Said second signal and said fourth signal are inputted to a second dual gate circuit and are mixed in the second dual gate circuit. The first dual gate circuit and the second dual gate circuit are arranged so that the output signals thereof are superposed with each other.
In the double-balanced mixer circuit having the constitution as described above, when the first frequency signal is inputted to the first phase shifter, the first phase shifter outputs the first signal having a phase lag of 90° from the first frequency signal and a second signal having a phase lead of 90° over the first frequency signal. When the second frequency signal is inputted to the second phase sifter, the second phase shifter outputs the third signal having a phase lag of 90° from the second frequency signal and the fourth signal having a phase lead of 90° over the second frequency signal.
The dual gate circuit is applied as a means for mixing signals based on non-linear characteristic. The dual gate circuit comprises a dual gate FET to use the non-linear characteristic of the dual gate FET. The principle will be briefly described below. Generally, the non-linear characteristic is capable of approximating the output by expanding the input in a progression. In the progression expansion expression, the first degree term shows the signals amplified and damped original signals, the second degree term shows the sum signal and the difference signal obtained the product of input signals, which are also amplified and damped. Although the signals corresponding to the third or higher degree term are output, these signals are small enough in amplitude to be disregarded.
The first dual gate circuit which has received the inputs of the first signal and the third signal outputs a signal generated by mixing the first signal and the third signal, the individual first signal and the individual third signal. The second dual gate circuit which has received the inputs of the second signal and the fourth signal outputs a signal generated by mixing the second signal and the fourth signal, the individual second signal and the individual fourth signal. The sum signal obtained by mixing the second signal and the fourth signal has the same phase as the sum signal obtained by mixing the first signal and the third signal. The difference signal obtained by mixing the second signal and the fourth signal has the same phase as the difference signal obtained by mixing the first signal and the third signal. When the signals output by the first dual gate circuit and the signals output by the second dual gate circuit are superposed, the original first and the individual second signals cancel each other and vanish because they are out of phase by 180°. Similarly, the individual third and the individual fourth signals cancel each other and vanish because they are out of phase by 180°. By superposing the sum signal of the first signal and the third signal and the sum signal of the second signal and the fourth signal, the signal whose amplitude is twice the sum signal of the first signal and the third signal is generated. By superposing the difference signal of the first signal and the third signal and the difference signal of the second signal and the fourth signal, the signal whose amplitude is twice the difference signal of the first signal and the third signal is generated. Consequently, only the radio frequency signal generated by mixing the first frequency signal and the second frequency signal is output.
The dual gate circuit which mixes the signals whose phases are different by 180° needs less FETs and transistors than the prior art, and needs no cascaded circuit of FETs, so that it is capable of reducing the power consumption in the circuit and using a lower voltage power source. The invention does not employ FETs (or transistors) in the first phase shifter and the second phase shifter. Consequently, it is capable of driving the double-balanced mixer circuit by even less power consumption and lower voltage, and also capable of obtaining an output signal which has a high S/N ratio because phase-shifted signals are not distorted.
Further another object of the invention is to provide a double-balanced mixer circuit capable of preventing the signal output from one duel gate circuit from entering the other dual gate circuit.
The double-balanced mixer circuit of the invention is further made in such a way that it includes, in addition to the first phase shifter, the second phase shifter, the first dual gate circuit and the second dual gate circuit, a coupler which, when the output signal of the first dual gate circuit and the output signal of the second dual gate circuit are inputted thereto, provides the superposed signal of the outputs on the output side thereof.
In this double-balanced mixer circuit, when the output signal of the first dual gate circuit and the output signal of the second dual gate circuit are inputted to the coupler, the radio frequency signal generated by superposing these signals is output.
Consequently, in view of the output side of the coupler, the possibility of the reverse flow of the radio frequency signal which is output from the coupler into the first dual gate circuit or the second dual gate circuit is reduced by setting the sum of the impedance of the components of the coupler and the output impedance of the FET which constitutes the dual gate circuit to a value higher than the impedance of the external circuit connected to the radio frequency output terminals.
The above and further objects and features of the invention will more fully be apparent from the following detailed description with accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a circuit diagram of a conventional double-balanced mixer circuit.
FIG. 2 is a circuit diagram of a phase inverter circuit.
FIG. 3 is a block circuit diagram illustrative of the constitution of the double-balanced mixer circuit of the invention.
FIG. 4 is a phase characteristic diagram of an output signal of a phase shifter.
FIG. 5 is an actual circuit diagram of the double-balanced mixer circuit of the invention.
FIG. 6 is an equivalent circuit diagram of a phase shifter comprising resistors and capacitors.
FIG. 7 is an actual circuit diagram illustrative of another constitution of the double-balanced mixer circuit of the invention.
FIG. 8 is an actual circuit diagram illustrative of further another constitution of the double-balanced mixer circuit of the invention.
FIG. 9 is an equivalent circuit diagram of a phase shifter comprising coils, resistors and capacitors.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Now the invention will be described in detail below with reference to the drawings illustrative of the preferred embodiments.
FIG. 3 is a block circuit diagram illustrative of the construction of a double-balanced mixer circuit of the invention. A local oscillation frequency signal LO having a frequency LO is inputted to a phase shifter PS1 comprising only passive elements, and an intermediate frequency signal IF having a frequency IF is inputted to a phase shifter PS2 comprising only passive elements. The phase shifter PS1 is made to output a signal LO' (frequency LO) with a phase lag of 90° from the local oscillation frequency signal LO and a signal #LO' (frequency LO) with a phase lead of 90° over the local oscillation frequency signal LO. The phase shifter PS2 is made to output a signal IF' (frequency IF) with a phase lag of 90° from the intermediate frequency signal IF and a signal #IF' (frequency IF) with a phase lead of 90° over the intermediate frequency signal IF.
The signal LO' output by the phase shifter PS1 is inputted to one input terminal of a dual gate circuit DG1 provided with, for example, a dual gate FET and the signal IF' output by the phase shifter PS2 is inputted to the other terminal of the dual gate circuit DG1. The signal output by #LO' of the phase shifter PS1 is inputted to one input terminal of a dual gate circuit DG2 provided with, for example, a dual gate FET and the signal #IF' output by the phase shifter PS2.
The dual gate circuit DG1 is made to mix the signal LO' and the signal IF', and the dual gate circuit DG2 is made to mix the signal #LO' and the signal #IF'. An output terminal of the dual gate circuit DG1 and an output terminal of the dual gate circuit DG2 are connected to each other, so that the signal output from the dual gate circuit DG1 and the signal output from the dual gate circuit DG2 are superposed. Then the radio frequency signal RF obtained by this superposition is output.
The operation of the double-balanced mixer circuit will now be described below with reference to FIG. 4 illustrative of the phase characteristic of the phase shifter PS1 (PS2).
When the local oscillation frequency signal LO is inputted to the phase shifter PS1, the phase shifter PS1 outputs a signal LO' with a phase lag of 90° from the local oscillation frequency signal LO and a signal #LO' with a phase lead of 90° over the local oscillation frequency signal LO as shown in FIG. 4. The signal LO' is inputted to one input terminal of the dual gate circuit DG1 and the signal #LO' is inputted to one input terminal of the dual gate circuit DG2. Similarly, when the intermediate frequency signal IF is inputted to the phase shifter PS2, the phase shifter PS2 outputs the signal IF' with a phase lag of 90° from the intermediate frequency signal IF and a signal #IF' with a phase lead of 90° over the intermediate frequency signal IF. The signal IF' is inputted to the other input terminal of the dual gate circuit DG1 and the signal #IF' is inputted to the other input terminal of the dual gate circuit DG2.
The dual gate circuit DG1 mixes the signal LO' and the signal IF' which have been inputted, and outputs signals LO'+IF' and LO'-IF' which are obtained by mixing and the individual signals LO' and IF'. The dual gate circuit DG2 mixes the signal #LO' and the signal #IF' which have been inputted, and outputs signals #LO'+#IF' and #LO'-#IF' which are obtained by mixing and the individual signals #LO' and #IF'.
These signals LO'+IF', LO'-IF', LO', IF', #LO'+#IF', #LO'-#IF', #LO' and #IF' are superposed (added) on the output side of the dual gate circuits DG1, DG2. The signal LO' and the signal #LO' cancel out each other because they have a phase difference of 180°, similarly the signal IF' and the signal #IF' cancel out each other because they have a phase difference of 180°, so that the individual signals LO', #LO', IF' and #IF' disappear.
The signal LO'+IF' and the signal LO'-IF' are generated from the component of the product of the signal LO' and the signal IF' by the dual gate FET applying the effect of the non-linear characteristic. Similarly the signal #LO'+#IF' and the signal #LO'-#IF' are generated from the component of the product of the signal #LO' and the signal #IF' by the dual gate FET applying the effect of the non-linear characteristic. The product of the signal #LO' having a phase being shifted by 180° from the signal LO' and the signal #IF' having a phase being shifted by 180° from the signal IF' has the same phase as the product of the signal LO' and the signal IF', so that the signal LO'+IF' is identical with the signal #LO'+#IF'. Similarly the signal LO'-IF' is identical with the signal #LO'-#IF'. Therefore the signal obtained by superposing the signals output by the dual gate circuit has twice in amplitude the signal output by the dual gate circuit.
Thus only the radio frequency signal RF which is generated by mixing is output with a high signal level, making it possible to obtain the output of the radio frequency signal RF of a high S/N ratio.
Also according to the invention, both the phase shifters PS1, PS2 are made by employing passive elements without using FETs, and the dual gate circuit is made by using a single dual gate FET. Therefore power consumption in the phase shifters PS1, PS2 and in the dual gate circuits DG1, DG2 can be greatly reduced. Also because no significant voltage drop occurs unlike the prior art wherein cascaded FETs are used, a low voltage power source can be used.
Moreover, the radio frequency signal RF is not subjected to distortion because phase shift is applied to the signals by using passive elements only. Furthermore, the circuit construction can be simplified because the dual gate circuit does not use many FETs. The dual gate FET provides excellent isolation of the local oscillation frequency signal LO and the intermediate frequency signal IF.
FIG. 5 shows a circuit diagram illustrative of an actual circuit of the double-balanced mixer circuit of the invention mounted on a GaAs substrate. Numerical figures appearing in parentheses in FIG. 5 are the values of resistance or capacitance in the conventional units of ohms or pico farads.
An input terminal t L for the local oscillation frequency signal LO is grounded via a resistor R 50 (50), and is grounded via a series circuit of a resistor R 51 (800), a resistor R 52 (800) and a capacitor C 50 (0.12). The junction of the resistor R 51 (800) and the resistor R 52 (800) is grounded via the capacitor C 51 (0.12). An input terminal t L is connected to one terminal of a resistor R 53 (720) via a series circuit of a capacitor C 52 (0.24) and a capacitor C 53 (0.24). The junction of the capacitors C 52 and C 53 is grounded via a resistor R 54 (400) and the junction of the capacitor C 53 and the resistor R 53 is grounded via a resistor R 55 (400). The phase shifter PS1 comprises the resistors R 51 , R 52 , R 53 , R 54 and R 55 and the capacitors C 50 , C 51 , C 52 and C 53 .
An input terminal t I for the intermediate frequency signal IF is grounded via a resistor R 56 (50), and is grounded via a series circuit of a resistor R 57 (1200), a resistor R 58 (1200) and a capacitor C 54 (0.5). The junction of the resistor R 57 (1200) and the resistor R 58 (1200) is grounded via a capacitor C 55 (0.5). The input terminal t I is connected to one terminal of a resistor R 59 (1080) via a series circuit of a capacitor C 56 (1.0) and a capacitor C 57 (1.0). The junction of the capacitor C 56 (1.0) and the capacitor C 57 (1.0) is grounded via a resistor R 60 (600) and the junction of the capacitor C 57 (1.0) and the resistor R 59 (1080) is grounded via a resistor R 61 (600). The phase shifter PS2 comprises the resistors R 57 , R 58 , R 59 , R 60 and R 61 and the capacitors C 54 , C 55 , C 56 and C 57 .
The power supply V DD is grounded via a series circuit of a resistor R 62 (5k) and a resistor R 63 (620), and is grounded via a series circuit of a resistor R 64 (5k) and a resistor R 65 (620). The junction of the resistor R 64 (5k) and the resistor R 65 (620) is connected to one input terminal (gate) of a dual gate FET 100 via a resistor R 66 (5k), and the junction of the resistor R 62 (5k) and the resistor R 63 (620) is connected to the other input terminal (gate) of a dual gate FET 100 via a resistor R 67 (5k). One output lead (source) of the dual gate FET 100 is grounded via a parallel circuit of a resistor R 68 (82) and a capacitor C 58 (14).
The gate width Wg of the dual gate FET 100 is made to be 600 μm, and both pairs of the gate and the source are biased to -0.3 V. The dual gate circuit DG1 comprises the dual gate FET 100, the resistors R 62 , R 63 , R 64 , R 65 , R 66 , R 67 , R 68 and the capacitor C 58 .
The power supply V DD is grounded via a series circuit of a resistor R 69 (5k) and a resistor R 70 (620), and is grounded via a series circuit of a resistor R 71 (5k) and a resistor R 72 (620). The junction of the resistor R 71 (5k) and the resistor R 72 (620) is connected to one input terminal (gate) of a dual gate FET 101 via a resistor R 73 (5k). The junction of the resistor R 69 (5k) and the resistor R 70 (620) is connected to the other input terminal (gate) of the dual gate FET 101 via a resistor R 74 (5k).
One output terminal (source) of the dual gate FET 101 is grounded via a parallel circuit of a resistor R 75 (82) and a capacitor C 59 (14). The width of the gates Wg of the dual gate FET 101 are made to be 600 μm, and both pairs of the gate and the source are biased to -0.3 V. The dual gate circuit DG2 comprises the dual gate FET 101, the resistors R 69 , R 70 , R 71 , R 72 , R 73 , R 74 , R 75 and the capacitor C 59 .
The junction of the resistor R 52 (800) and the capacitor C 50 (0.12) of the phase shifter PS1 is connected to one input terminal of the dual gate FET 100, and the junction of the resistor R 58 (1200) and the capacitor C 54 (0.5) of the phase shifter PS2 is connected to the other input terminal of the dual gate FET 100. The other terminal of the resistor R 53 (720) of the phase shifter PS1 is connected to one input terminal of the dual gate FET 101, and the other terminal of the resistor R 59 (1080) of the phase shifter PS2 is connected to the other input terminal of the dual gate FET 101.
The other output (drain) of the dual gate FET 100 and the other input (drain) of the dual gate FET 101 are combined and connected to a radio frequency output terminal t H whereon the radio frequency signal RF is output. The radio frequency output terminal t H is grounded via a series circuit of a resistor R 76 (50) and a capacitor C 60 (14). The junction of the resistor R 76 (50) and the capacitor C 60 (14) is connected to the power supply V DD via a parallel circuit of a capacitor C 61 (2.34) and a coil L of 3 nH. The voltage of the power supply V DD is set to 3 V.
FIG. 6 shows an equivalent circuit diagram explanatory of the conditions to determine the values of the resistors and capacitors of the phase shifters PS1, PS2. Resistors R 51 , R 52 of the phase shifter PS1 shown in FIG. 5 correspond to R B , R B , resistors R 54 , R 55 correspond to R A , R A , capacitors C 50 , C 51 correspond to C B , C B , and capacitors C 52 , C 53 correspond to C A , C A . Resistors R 57 , R 58 of the phase shifter PS2 correspond to R B , R B , resistors R 60 , R 61 correspond to R A , R A , capacitors C 54 , C 55 correspond to C B , C B , and capacitors C 56 , C 57 correspond to C A , C A . The values of the resistors and the capacitors are determined by the following formulae.
R.sub.B =2·R.sub.A (1)
C.sub.B =(1/2)·C.sub.A (2)
where
1/(R.sub.A ·C.sub.A)=1/(R.sub.B ·C.sub.B)=2πf(3)
must be satisfied. Frequency f is 1.65 GHz for the local oscillation frequency signal LO, and 0.25 GHz for the intermediate frequency signal IF.
When the local oscillation frequency signal LO and the intermediate frequency signal IF are inputted to the double-balanced mixer circuit having the construction as described above, the phase shifter PS1 outputs a signal LO' with a phase lag of 90° from the local oscillation frequency signal LO and a signal #LO' with a phase lead of 90° over the local oscillation frequency signal LO, and the phase shifter PS2 outputs a signal IF' with a phase lag of 90° from the intermediate frequency signal IF and a signal #IF' with a phase lead of 90° over the intermediate frequency signal IF, as described previously. The dual gate circuit DG1 mixes the signal LO' and the signal IF', and the dual gate circuit DG2 mixes the signal #LO' and the signal #IF'.
Mixed signals LO'+IF', LO'-IF', #LO'+#IF' and #LO'-#IF' are output from the dual gate circuits DG1, DG2, and are superposed to produce the radio frequency signals RF, having frequencies of LO+IF and LO-IF and twice the amplitude of the original signal, which are output at the radio frequency output terminal t H . The signals LO' and IF' which are output individually from the dual gate circuit DG1 and the signals #LO' and #IF' which are output individually from the dual gate circuit DG2 cancel out each other and disappear.
It was verified with this actual circuit that, when the local oscillation frequency signal LO having a frequency of 1.65 GHz and the intermediate frequency signal IF having a frequency of 0.25 GHz were inputted with a level of -5 dBm, radio frequency signal RF having a frequency of 1.9 GHz was obtained with a voltage amplitude of 50 mV.
As described above, because the dual gate circuits and the phase shifters which do not employ FETs and transistors but passive elements are used in the double-balanced mixer circuit of the invention, power consumption can be greatly reduced. Also because no significant voltage drop occurs in the phase shifters and the dual gate circuits, a low voltage power source can be used. Moreover, even when signals having large amplitudes are inputted to the phase shifter, distortion of the signal is prevented by building the phase shifter of passive elements.
FIG. 7 shows an actual circuit diagram illustrative of another embodiment of the double-balanced mixer circuit of the invention. Numerical figures indicated in parentheses in FIG. 7 are the values of inductance, resistance and capacitance in units of nH, ohms and pico farads, respectively.
An input terminal t L for the local oscillation frequency signal LO is grounded via a series circuit of a coil L 30 (6.3) and a capacitor C 30 (0.3). A matching circuit MC1 comprises the coil L 30 (6.3) and the capacitor C 30 (0.3). The junction of the coil L 30 (6.3) and the capacitor C 30 (0.3) is grounded via a series circuit of a resistor R 30 (200), a resistor R 31 (200) and a capacitor C 32 (0.482), and the junction of the resistor R 30 (200) and the resistor R 31 (200) is grounded via a capacitor C 31 (0.482).
The junction of the coil L 30 (6.3) and the capacitor C 30 (0.3) is grounded via a series circuit of the capacitor C 33 (0.964) the capacitor C 34 (0.964) and the resistor R 33 (100). The junction of the capacitor C 33 (0.964) and the capacitor C 34 (0.964) is grounded via the resistor R 32 (100). The junction of the capacitor C 34 (0.964) and the resistor R 33 (100) is connected to one lead of the capacitor C 35 (1.0). The phase shifter PS1 comprises the resistors R 30 , R 31 , R 32 , R 33 and the capacitors C 31 , C 32 , C 33 , C 34 , C 35 .
An input terminal t I for the intermediate frequency signal IF is grounded via a series circuit of a coil L 31 (100), a capacitor C 36 (1000) and a capacitor C 37 (3.1). The coil L 31 (100) and the capacitor C 36 (1000) are connected on the outside. A matching circuit MC2 comprises the coil L 31 and the capacitors C 36 , C 37 . The junction of the capacitor C 36 (1000) and the capacitor C 37 (3.1) is grounded via a series circuit of a capacitor C 38 (1.06), a capacitor C 39 (1.06) and a resistor R 35 (600). The junction of the capacitor C 38 (1.06) and the capacitor C 39 (1.06) is grounded via the resistor R 34 (600). The junction of the capacitor C 39 (1.06) and the resistor R 35 (600) is connected to one terminal of a capacitor C 40 (1.0).
The junction of the capacitor C 36 (1000) and the capacitor C 37 (3.1) is grounded via a series circuit of a resistor R 36 (1200), a resistor R 37 (1200) and a capacitor C 42 (0.53). The junction of the resistor R 36 (1200) and the resistor R 37 (1200) is grounded via a capacitor C 41 (0.53). The phase shifter PS2 comprises the resistors R 34 , R 35 , R 36 , R 37 and the capacitors C 38 , C 39 , C 40 , C 41 and C 42 .
The junction of the resistor R 31 (200) and the capacitor C 32 (0.482) of the phase shifter PS1 is connected to one terminal (gate) of the dual gate FET 102, and the other terminal of the capacitor C 40 (1.0) of the phase shifter PS2 is connected to the other input terminal (gate) of the dual gate FET 102. One input terminal of the dual gate FET 102 is grounded via a resistor R 38 (3k), and the other input terminal is grounded via a resistor R 39 (3k). The gate width Wg of the dual gate FET 102 is made to be 400 μm, and the gate length of one input terminal 0.7 μm and the gate length of the other input terminal 0.5 μm.
The junction of the resistor R 37 (1200) and the capacitor C 42 (0.53) of the phase shifter PS2 is connected to one input terminal (gate) of the dual gate FET 103, and the other terminal of the capacitor C 35 (1.0) of the phase shifter PS1 is connected to the other input terminal (gate) of the dual gate FET 103. One input terminal of the dual gate FET 103 is grounded via a resistor R 41 (3k), and the other input terminal is grounded via a resistor R 40 (3k). The gate width Wg of the dual gate FET 103 is made to be 400 μm, and the gate length of one input lead 0.7 μm and gate length of the other input terminal 0.5 μm.
The dual gate circuit DG1 comprises the dual gate FET 102 and the resistors R 38 , R 39 , and the dual gate circuit DG2 comprises the dual gate FET 103 and the resistors R 40 , R 41 . One output terminal (source) of each of the dual gate FET 102 and the dual gate FET 103 is grounded. A capacitor C 43 (0.47) is inserted between the other output terminal (drain) of the dual gate FET 102 and the other output terminal (drain) of the dual gate FET 103, and the capacitor C 43 (0.47) is connected with a parallel pair of a series circuit of a coil L 31 (5.0) and a coil L 32 (5.0) and a series circuit of a capacitor C 44 (0.5) and a capacitor C 45 (0.5).
A coupler CPL comprises the capacitor C 43 , the coils L 31 , L 32 and the capacitors C 44 , C 45 . The junction of the capacitor C 44 (0.5) and the capacitor C 45 (0.5) is connected with a radio frequency output terminal t H where the radio frequency signal RF is output, via a parallel circuit of a capacitor C 46 (0.4) and a coil L 33 (8.0). The junction of the coil L 31 (5.0) and the coil L 32 (5.0) is connected the power supply V DD via a coil L 34 (200) which is connected on the outside. A matching circuit MC3 comprises the capacitor C 46 and the coil L 33 .
The coupler CPL are constructed so that the impedance of the coupler CPL at the radio frequency output terminal t H side plus the output impedance of the dual gate FET 102 is greater than the impedance of the circuit to be connected to the radio frequency output terminal t H .
When the local oscillation frequency signal LO and the intermediate frequency signal IF are inputted to the double-balanced mixer circuit of the constitution as described above, the phase shifter PS1 outputs the signal LO' having a phase lag of 90° from the local oscillation frequency signal LO and the signal #LO' having a phase lead of 90° over the local oscillation frequency signal LO, and the phase shifter PS2 outputs the signal IF' having a phase lag of 90° from the intermediate frequency signal IF and the signal #IF' having a phase lead of 90° over the intermediate frequency signal IF, similarly as described previously. The dual gate circuit DG1 mixes the signal LO' and the signal IF', and the dual gate circuit DG2 mixes the signal #LO' and the signal #IF'.
Mixed signals LO'+IF', LO'-IF', #LO'+#IF', #LO'-#IF', and the individual signals LO', IF', #LO', #IF' are output from the dual gate circuits DG1, DG2, and are superposed on the output side of the coupler CPL, to provide the radio frequency signals RF, having frequencies of LO+IF and LO-IF and twice the amplitude of the original signal, at the radio frequency output terminal t H .
The signals LO' and IF' which are output individually from the dual gate circuit DG1 and the signals #LO' and #IF' which are output individually from the dual gate circuit DG2 cancel out each other thereby to disappear.
By providing the coupler CPL, it is made less likely that the signals LO'+IF', LO'-IF' which are output from the dual gate circuit DG1 via the capacitor C 44 (0.5) flow to the dual gate circuit DG2. It is also made less likely that the signals #LO'+#IF', #LO'-#IF' which are output from the dual gate circuit DG2 via the capacitor C 45 (0.5) flow to the dual gate circuit DG1. Therefore, the levels of the mixed signals LO'+IF', LO'-IF', #LO'+#IF', #LO'-#IF' do not decrease on the output side of the coupler CPL, and these signals can be superposed with high efficiency and output at the radio frequency output terminal t H .
It was verified experimentally that, when the power voltage V DD was set to 3 V, the frequency of the local oscillation frequency signal LO was set to 1.65 GHz, the frequency of the intermediate frequency signal IF was set to 0.25 GHz, and the frequency of the radio frequency signal RF was set to 1.9 GHz, conversion gain of 0 dBm was obtained from the input of the local oscillation frequency signal LO of 5 dBm and the input of the intermediate frequency signal IF of 0 dBm.
FIG. 8 shows an actual circuit diagram illustrative of further another constitution of the double-balanced mixer circuit of the invention. Numerical figures indicated in parentheses in FIG. 8 are the values of inductance, resistance and capacitance in the unit of nH, ohm and pico farad, respectively.
An input terminal t L for the local oscillation frequency signal LO is grounded via a parallel circuit of a capacitor C 80 (0.5) and a resistor R 80 (35) and a series circuit of a coil L 80 (5.0) and a resistor R 81 (100). The junction of the coil L 80 (5.0) and the resistor R 81 (100) is grounded via a capacitor C 81 (1.86). The junction of the capacitor C 80 (0.5), the resistor R 80 (35) and the coil L 80 (5.0) is grounded via a series circuit of a capacitor C 82 (1.86) and a resistor R 82 (100), and the junction of the capacitor C 82 (1.86) and the resistor R 82 (100) is grounded via a coil L 81 (5.0). A matching circuit MC1 comprises the capacitor C 80 and the resistor R 80 . The phase shifter PS1 comprises the coils L 80 , L 81 , the capacitors C 81 , C 82 and the resistor R 81 , R 82 .
An input terminal t I for the intermediate frequency signal IF is grounded via a series circuit of a coil L 82 (100), a capacitor C 83 (1000), a capacitor C 84 (1.06), a capacitor C 85 (1.06) and a resistor R 84 (600). The junction of the capacitor C 84 (1.06) and the capacitor C 85 (1.06) is grounded via a resistor R 83 (600). The junction of the resistor R 84 (600) the and capacitor C 85 (1.06) is connected to one terminal of a capacitor C 86 (1.0).
The junction of the capacitor C 83 (1000) and the capacitor C 84 (1.06) is grounded via a series circuit of a resistor R 85 (1200), a resistor R 86 (1200) and a capacitor C 88 (0.53), and the junction of the resistor R 85 (1200) and the resistor R 86 (1200) is grounded via a capacitor C 87 (0.53). The coil L 82 and the capacitor C 83 are connected on the outside, and a matching circuit MC2 comprises the coil L 82 and the capacitor C 83 . The phase shifter PS2 comprises the capacitors C 84 , C 85 , C 86 , C 87 , C 88 and the resistors R 83 , R 84 , R 85 , R 86 .
The junction of the coil L 80 (5.0), the capacitor C 81 (1.86) and the resistor R 81 (100) of the phase shifter PS1 is connected to one terminal (gate) of the dual gate FET 104. The other terminal of the capacitor C 86 (1.0) of the phase shifter PS2 is connected to the other input lead (gate) of the dual gate FET 104. One input terminal of the dual gate FET 104 is grounded via a resistor R 87 (3k), and the other input terminal is grounded via a resistor R 88 (3k). The gate width Wg of the dual gate FET 104 is made to be 200 or 400 μm. The dual gate circuit DG1 comprises the dual gate FET 104, resistors R 87 and R 88 .
The junction of the resistor R 86 (1200) and the capacitor C 88 (0.53) of the phase shifter PS2 is connected to one input terminal (gate) of the dual gate FET 105. The junction of the capacitor C 82 (1.86), the coil L 81 (5.0) and the resistor R 82 (100) of the phase shifter PS1 is connected to the other input terminal (gate) of the dual gate FET 105. One input terminal of the dual gate FET 105 is grounded via a resistor R 90 (3k), and the other input terminal is grounded via a resistor R 89 (3k). The gate width of the dual gate FET 105 is made to be 200 or 400 μm. The dual gate circuit DG2 comprises the dual gate FET 105, the resistors R 89 and R 90 .
One output terminal (source) of the dual gate FET 104 and one output terminal (source) of the dual gate FET 105 are grounded. A capacitor C 89 (0.47) is inserted between the other output terminal (drain) of the dual gate FET 104 and the other output terminal (drain) of the dual gate FET 105. The capacitor C 89 (0.47) is connected to a parallel combination of a series circuit of the coil L 82 (5.0) and the coil L 83 (5.0) and a series circuit of a capacitor C 90 (0.5) and a capacitor C 91 (0.5).
A coupler CPL comprises the capacitors C 89 , C 90 , C 91 and the coils L 82 , L 83 . The junction of the capacitor C 90 (0.5) and the capacitor C 91 (0.5) is connected with the radio frequency output terminal t H , where the radio frequency signal RF is output, via a parallel circuit of a capacitor C 92 (0.4) and a coil L 84 (8.0). A matching circuit MC3 comprises the capacitor C 92 and the coil L 84 . The junction of the coil L 82 (5.0) and the coil L 83 (5.0) is connected to the power supply V DD via a coil L 85 (200).
The coupler CPL is constructed so that the impedance of the coupler CPL at the radio frequency output terminal t H side plus the output impedance of the dual gate FET 104 is greater than the impedance of the circuit to be connected to the radio frequency output terminal t H .
FIG. 9 shows an equivalent circuit diagram explanatory of the conditions to determine the values of the coils, resistors and capacitors of the phase shifter PS1. The coils L 80 , L 81 of the phase shifter PS1 shown in FIG. 8 correspond to L A , L A , the resistors R 81 , R 82 correspond to R C , R C , and the capacitors C 81 , C 82 correspond to C C , C C . The values of the coils, resistors and capacitors are determined by the following formula.
(L.sub.A ·C.sub.C).sup.-1/2 =2πf (4)
Where frequency f is 1.65 GHz for the local oscillation frequency signal LO, and 0.25 GHz for the intermediate frequency signal IF.
When the local oscillation frequency signal LO and the intermediate frequency signal IF are inputted to the double-balanced mixer circuit of the constitution as described above, the phase shifter PS1 outputs a signal LO' having a phase lag of 90° from the local oscillation frequency signal LO and a signal #LO' with a phase lead of 90° over the local oscillation frequency signal LO, similarly as described previously. And the phase shifter PS2 outputs a signal IF' having a phase lag of 90° from the intermediate frequency signal IF and a signal #IF' having a phase lead of 90° over the intermediate frequency signal IF, similarly as described previously. The dual gate circuit DG1 mixes the signal LO' and the signal IF', and the dual gate circuit DG2 mixes the signal #LO' and the signal #IF'. This is followed by an operation similar to that described previously, to provide the radio frequency signal RF having frequencies of LO+IF and LO-IF at the radio frequency output terminal t H .
The voltage gain of the phase shifter PS1, which is the ratio of the output voltage to the input voltage thereof, is determined by the values of the coils, resistors and capacitors which constitute the phase shifter. When the values of the coils, resistors and capacitors which constitute the phase shifter PS1 are as shown in FIG. 8, the voltage gain of 5.6 dB is obtained for the phase shifter PS1 with a coefficient X for determining the voltage gain being given by the formula (5) from which X=0.26 is obtained.
X=(L.sub.A /C.sub.C).sup.1/2 /(2·R.sub.C) (5)
Thus a voltage gain comparable to that obtained with a phase shifter comprising resistors and capacitors can be obtained, thereby verifying that the phase shifter having the construction as described above can be used in a practical application similarly to the phase shifter comprising resistors and capacitors.
Because this embodiment has, in addition to the effects of foregoing embodiments, the effect of making it less likely that the signal which is output to the output side of the coupler flow to the dual gate circuit, the signal level does not decrease at the output side of the coupler, thereby enabling it to efficiently superpose the signals on the output side of the coupler.
Although one phase shifter PS1 comprises the coils, resistors and capacitors and another phase shifter PS2 comprises the resistors and capacitors in this embodiment, the phase shifter PS2 can also be made from coils, resistors and capacitors. While the coil becomes larger in size in this case which makes it impossible to incorporate it in the MMIC (Monolithic Micro wave IC), connecting the phase shifter to the IC on the outside makes this construction applicable to practical use.
Although a case of mixing the local oscillation frequency signal and the intermediate frequency signal is described in this embodiment, the invention can also be applied with similar effects, for example, to a reception signal mixer circuit, an analog multiplier circuit, a frequency conversion circuit or the like where it is required to mix signals of different frequencies.
Although the phase shifters comprises only passive elements in foregoing embodiments, the phase shifters can also comprise FETs. In this case power consumption is larger than foregoing embodiments, but it can be made smaller than the prior art because the dual gate circuit is used for performing the double-balance.
As this invention may be embodied in several forms without departing from the spirit of essential characteristics thereof, the present embodiment is therefore illustrative and not restrictive, since the scope of the invention is defined by the appended claims rather than by the description preceding them, and all changes that fall within metes and bounds of the claims, or equivalence of such metes and bounds thereof are therefore intended to be embraced by the claims. | A double-balanced mixer circuit which consumes less power, and is capable of operating on a low voltage power source, because an output of a first signal having a phase lag of 90° from a first frequency signal and an output of a second signal having a phase lead of 90° over the first frequency signal are provided by means of a first phase shifter, an output of a third signal having a phase lag of 90° from a second frequency signal and an output of fourth signal having a phase lead of 90° over the second frequency signal are provided by means of a second phase shifter, thereby generating a radio frequency signal by mixing the first signal and the third signal in a first dual gate circuit, and generating a radio frequency signal by mixing the second signal and the fourth signal in a second dual gate circuit. | 7 |
FIELD OF THE INVENTION
[0001] The present invention is directed to a verification and coating apparatus and method for applying a material to a workpiece, and more particularly to a verification and coating apparatus and method for applying a primer coating to a ultrasonically verified clear pre-primer coating on an edge of a windshield, lights, and/or back window.
BACKGROUND
[0002] Insulation of fixed windows in automotive vehicles previously required manual installation of a glazing unit using suitable mechanical fasteners, such as metal clips, for securing the glazing unit with respect to the vehicle body. Sealant typically was applied around the marginal edges of the glazing unit, prior to positioning decorative strips around the glazing unit to conceal the interface between the marginal edges of the glazing unit and the adjacent portions of the vehicle body. Manual assembly and installation of glazing units was inefficient, expensive, and not amenable to accommodate increased automotive production on an automated automobile assembly line.
[0003] Unitary window assemblies were later developed to provide a sheet of glass with an adjacent peripheral frame. A gasket of molded material extended between the frame and the peripheral margin of the window to hold the glass sheet within the frame. Fasteners were provided at spaced locations along the frame to permit the entire assembly to be guided into position over an appropriate opening in a vehicle and to secure the entire assembly to the vehicle as a unit. While this window structure reduced the assembly time and simplified installation of the window unit in a vehicle opening, the labor required to manually assemble the frame and gasket with respect to the glass resulted in a relatively high cost per unit.
[0004] Individual sheets of glass or laminated glass units have been formed with integral frame or gasket members molded and cured in situ by injection molding. These configurations seek to eliminate the manual assembly of the unit. The assembly has been referred to as an encapsulated glazing unit. The encapsulated glazing units require a minimum of manual labor for assembly and can be readily attached to openings through the vehicle body during assembly on an automated production line. A predetermined portion of the marginal periphery of a sheet of transparent material is disposed within a mold structure during fabrication of the encapsulated glazing unit. A polymeric gasket forming material is injected into the mold cavity and cured in situ on the sheet to encapsulate the marginal peripheral edge portion of the sheet. The resulting assembly is readily attachable to a periphery defining a window opening through a vehicle body during manufacturer and assembly of the vehicle.
[0005] It is known to be difficult to form a gasket material having a permanent, long term bond directly to a glass surface. The gasket materials can fail to maintain adhesion to the glass surface for a sufficient length of time to be consistent with the life of the vehicle. Exposure to environmental conditions can cause gasket material to loosen from the glass surface over time, and ultimately may separate entirely from the glass surface. It is known to apply a coating of a liquid primer material to the effected surface of the glass prior to formation of a gasket thereon in order to improve the adherence of a gasket material to the glass surface and to increase the expected life of the encapsulated glazing unit. A band of the primer material along the appropriate edge portion of the glass panel can be applied manually or through automated processing equipment. The primer layer, typically a urethane material, is best applied as a uniform, continuous, relatively thin band in order to function properly. The primer layer may separate within an excessively thick layer along a cleavage plane resulting in failure of the bond. The primer layer may be ineffective for its intended purpose if not of sufficient thickness or of certain areas are not coated.
[0006] A programed robot or other motion device can be used to define a path of travel coinciding with a perimeter or other path associated with a product to be coated. Applications can involve depositing primer material, paint material, activator material, adhesive material, or the like to aid in the attachment of foam tapes, plastic moldings, metal components, such as hinges, locks, and all types of encapsulated products.
[0007] Prior to the application of certain primer materials, it is known to be advantageous to provide a pre-primer coating or surface treatment of a glass surface in order to better adhere the primer coating to the glass surface. Certain pre-primer coatings for glass surfaces clean or etch the glass surface in preparation for the application of the primer coating. The pre-primer coating or surface treatment can dry to a clear, transparent, virtually invisible, surface. In such applications, it is difficult to visually verify proper application of the pre-primer coating prior to application of the primer coating to the glass surface. Failure to properly pre-prime the glass surface can result in failure or unsatisfactory performance of the primer coating in performing its intended function. It would be desirable to provide an apparatus and method for verification of the presence and proper application of the pre-primer material prior to the application of the primer material layer.
SUMMARY
[0008] The verification and coating apparatus and method according to the present invention will generally be described with regard to a particular automotive application, since one of the primary applications of the verification and coating apparatus and method is the automotive glass industry where a material applicator is used to apply various fluids to an edge of a windshield, side light, and/or a backlight glass. However, it should be understood that the present invention is also suitable for a wide range of other material applying applications. The automotive glass application description is therefore by way of example and not limitation with respect to the possible applications of the present invention. The present invention is particularly adapted for the production of glazing units or window assemblies for automotive vehicles, although it will find utility generally in other material application fields as well.
[0009] The present invention provides an apparatus and process for applying a material layer to a workpiece for a vehicle. By way of example and not limitation, a contoured glass workpiece can have a pre-primer material layer applied along a predetermined path on a surface of the workpiece leaving a residual film. An ultrasonic sensor can be provided for identifying a workpiece configuration, and for verifying presence of the residual film of pre-primer material layer along the predetermined path on the surface of the workpiece. A first applicator can be provided for applying a primer material layer over the pre-primer material layer on a surface of the workpiece, if presence of the residual film is verified by the ultrasonic sensor. A second applicator can be provided for applying a urethane sealant material layer over the primer material layer on the surface of the workpiece.
[0010] A process according to the present invention can be used for applying a layer of material to a workpiece for a vehicle. By way of example and not limitation, the process according to the present invention can include the steps of ultrasonically verifying a residual film from a first material layer previously applied to a surface of a workpiece, and if verified, applying a second material layer over the first material layer on the surface of the workpiece. The first material layer can include a pre-primer material layer covering at least a portion of the surface of the workpiece along a predetermined path. The second material layer can include a primer material applied over the first material layer on the surface of the workpiece. A third material layer can be provided for application over the second material layer on the surface of the workpiece. By way of example and not limitation, the third material layer can be a urethane sealant material for connecting and sealing a contoured glass workpiece to an opening in a vehicle body. If the residual film from the first material layer is not verified, the workpiece can be rejected as being defective prior to further processing.
[0011] According to the present invention, the apparatus and process encompass different workstation configurations providing various degrees of processing flexibility and production throughput. The apparatus and process according to the present invention can also identify at least one of a pattern, size, and shape of a workpiece to be processed, and based on the identification can select material layers to be applied, in sequence of application of the material layers, and a path of applicator travel.
[0012] Other applications of the present invention will become apparent to those skilled in the art when the following description of the best mode contemplated for practicing the invention is read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The description herein makes reference to the accompanying drawings wherein like reference numerals refer to like parts throughout the several views, and wherein:
[0014] FIG. 1 is a simplified schematic plan view of a black prime application to heated glass projected to be capable of processing 20 jobs per hour;
[0015] FIG. 2 is a simplified schematic plan view of a red and black prime application workstation projected to be capable of processing 65 jobs per hour;
[0016] FIG. 3 is a simplified schematic plan view of a red and black prime application workstation projected to be capable of processing 130 jobs per hour; and
[0017] FIG. 4 is a simplified flow diagram illustrating various process steps according to one example of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0018] Referring now to FIG. 1 , a workstation 10 is illustrated including a plurality of glass workpiece racks 12 . At least one workpiece rack 12 can be provided for workpieces to be processed, while at least one rack 12 can be provided for workpieces that have been processed. An operator load assist fixture 14 can be provided with a bridge 16 and rails 18 . The load assist fixture 14 can include 90 degrees of motion (horizontal to vertical). Hand controls can be provided for manual or automated motion of the fixture. Vacuum cups and control circuitry can be provided connected to a source of vacuum for selectively engaging and disengaging a workpiece to be loaded and/or unloaded from the storage rack 12 for delivery to and from a glass nesting fixture 20 . By way of example and not limitation, the glass nesting fixture 20 can include a 2 inch diameter tube frame construction with leveling. Vacuum cups and control circuitry can be provided for holding the workpiece in place within the nesting fixture 20 . Bumpers with threaded rod adjustment can also be provided for location of the workpiece with respect to the nesting fixture 20 . Part present limit switches can be provided to signal the presence of a workpiece within the nesting fixture 20 . Locators can also be provided for shifting the workpiece into a predetermined location with respect to the nesting fixture in response to actuation of the part present limit switches. At least one robot or other automated material application equipment 22 is provided for operative interaction with the workpiece 12 mounted within the nesting fixture 20 at the workstation 10 . The robot or other material application equipment is in fluid communication with material dispense equipment 24 for supplying the material to be applied to a surface of the workpiece 12 held in the nesting fixture 20 . One or more ventilation ducts 26 can be provided for ventilating the area of the workstation 10 . A control panel 28 can be provided for controlling the robot or other material application equipment 22 in order to apply the appropriate material in the desired application sequence, and along a programmable path based on an identification of the pattern, size, and/or shape of the workpiece to be processed. The control panel 28 can include an emergency stop button 30 . A workstation control panel 32 can be provided for controlling the operation of the nesting fixture 20 and/or for controlling the operation of the load assist fixture 14 . The workstation control panel 32 can include an emergency stop button 34 . A safety run bar or switch 36 can be provided for dual handed operation by the loading and unloading operator to cycle the fixturing of the next workpiece to be processed and cycling the operation of the robot or material application equipment to dispense the appropriate selected material in the selected application sequence along a programmed path based on an identification of the pattern, size, and/or shape of the workpiece to be processed. A main input/output enclosure panel 38 can be provided for the workstation. The main panel can route power and/or control lines to and from the workstation 10 with appropriate switches, breakers, and diagnostic lights to simplify proper operation of the workstation 10 . A supplemental enclosure panel 40 can also be provided if desired to interface power and/or control signals with the material dispense equipment 24 and to interact with the robot or material application equipment control panel 28 .
[0019] In operation, a workstation operator uses the load assist fixture 14 to remove an unprimed workpiece from the storage rack 12 and moves the workpiece along the bridge and rails 16 , 18 to a position to load the nesting fixture 20 . After loading the unprimed workpiece in the nesting fixture 20 , the operator activates the run bar or switch 36 to activate the holding, and/or clamping and/or locating components of the nesting fixture 20 , and to activate an identification of the workpiece by pattern, size, and/or shape of the workpiece. An identification signal is sent to the control panel 28 for the robot or other material application equipment 22 where the appropriate material is selected, the appropriate application sequence is selected, and a programmed path based on the identification signal of the workpiece is selected for automatic application of the material along the programmed path for applying material to a surface of the workpiece to be processed. The pattern, size, and/or shape of the workpiece can be identified in a variety of ways. By way of example and not limitation, the workpiece can be identified by operator input, either directly through a keypad entry or through a bar code scanning, or can be identified with a computerized vision system. In the preferred configuration, an ultrasonic identification system can be used to identify the particular workpiece placed in the nesting fixture 20 . The ultrasonic system can also be used to detect a residual pre-primer film on a surface of a workpiece positioned in the nesting fixture 20 of the workstation 10 . If the pre-primer coating is detected as existing in the desired area of the surface of the workpiece, the robot or other material application equipment 22 is activated to apply a primer material layer over the residual film in preparation for subsequent application of a third material layer. By way of example and not limitation, the third material layer can include a urethane sealant material layer to be applied over the primer material layer applied by the robot or other material application equipment 22 . If the residual pre-primer film is not detected on the surface of the workpiece, the robot can be prevented from applying the primer layer to the surface of the workpiece, and the control panel can signal a rejected workpiece. The robot or material application equipment 22 can be returned to a ready position allowing removal of the workpiece from the nesting fixture 20 . The nesting fixture 20 can be de-energized to release any clamps or suction cup vacuum holding the workpiece in position within the nesting fixture 20 . The load/unload assist fixture 14 can be manipulated along the bridge and rails 18 in order to operably engage the workpiece within the nesting fixture 20 in order to lift and move the workpiece from the nesting fixture 20 to a primed workpiece storage rack 12 . The load/unload assist fixture 14 can include appropriate clamps and/or vacuum suction cups to operably engage and hold the workpiece during the transport procedure. After the primed workpiece has been transported along the rails and across the bridge to an appropriate storage rack 12 and properly positioned therein, the assist fixture 14 can be de-energized to release any clamps and/or vacuum suction cups to transfer the workpiece from the assist fixture 14 to the storage rack 12 . The assist fixture 14 can then be moved along the rail to an unprimed workpiece storage rack 12 where a subsequent unprimed workpiece is operably engaged for transport to the nesting fixture 20 . The entire process is then repeated for the unprimed workpiece. If a workpiece has been rejected for failing to include a pre-primer coating in the appropriate areas on the surface of the workpiece, the workpiece can be removed from the nesting fixture 20 with the assist fixture 14 for transportation to an appropriate rejected part storage rack 12 .
[0020] By way of example and not limitation, suitable ultrasonic identification systems can be obtained from Quiss GmbH of Puchheim, Germany. The system can check the width, position, and completeness of the pre-primer coating on the surface of the workpiece, as well as the width, position, and completeness of the primer being applied continuously during the application process. The system can be equipped with extremely fast algorithms so that inspection can be conducted in real time at production speeds. The system can be directly connected to the robot controller, and the sensor can be used with all conventional fuel bus systems. The commercially available system allows target values and tolerance ranges to be quickly entered in the programming device and the operating status can be displayed directly on the robot controller. The image processing software can be integrated in the sensor, independent of the technology package installed on the robot controller to enable the sensor to be operated independently of the robot in use. The sensor can be easily integrated into any robot. The sensor can include a camera and lighting. The sensor can be mounted directly to a material application nozzle or other tool. The basic configuration can include a control cabinet and a visualization and control unit. Any number of cameras can be used depending on production conditions. The sensors and the components can be provided in a fixed position installation, or it can be provided in a mobile installation attached to the robot or other material application equipment for movement along the desired path of travel during application of the material to the surface of the workpiece. The result in parameter data can be displayed and edited at the workstation, or at a host computer, or at any authorized computer in a network.
[0021] It has been estimated that a black prime application with heated glass can be applied in a workstation according to the configuration illustrated in FIG. 1 at a rate of 20 jobs per hour. If increased production is desired with red and black prime application, the configuration illustrated in FIG. 2 has been estimated to provide production at a rate of 65 jobs per hour. The configuration at operation of FIG. 2 is identical to that previously described with respect to FIG. 1 with the exception of the addition of a two station index table 42 having 180 degree oscillating or rotary movement about a rotational axis. The table top frame allows first and second nesting fixtures 20 a, 20 b to be attached to diametrically opposite ends of the table for oscillating movement between first and second positions corresponding to a loading/unloading position, and a processing position. This allows the workstation operator to unload a primed workpiece from one nesting fixture 20 a or 20 b while the robot or other material application equipment 22 applies material to the workpiece located at the processing position in the other nesting fixture 20 b or 20 a. During the time required for the robot to apply one or more layers of material to the workpiece at the processing location or position, the workstation operator can unload a finished piece from the other nesting fixture for transport to an appropriate coated workpiece storage rack 12 , and load another uncoated workpiece from an appropriate uncoated workpiece storage rack 12 for delivery to the empty nesting fixture. After the uncoated workpiece has been loaded into the nesting fixture, and after the workpiece has been coated in the processing location, the turntable can oscillate to exchange the two workpieces between the loading/unloading position and the. processing position to repeat the sequence of steps for continued processing of workpieces. It should be recognized that the use of a turntable is considered to be the most efficient configuration as illustrated in the configurations of FIGS. 2 and 3 . However, it should be recognized by those skilled in the art that parts can be delivered to the processing position in any variety of forms, including various types of workpiece conveyors other than turntables. In the preferred configuration, the ultrasonic identification system can pattern match hundreds of different styles of workpieces to be processed through the workstation. The different styles are capable of being held stable within a nesting fixture having appropriately positioned vacuum cups. The ultrasonic vision system can identify the pattern, size, and/or shape of the workpiece in order to select the appropriate material to be applied, sequence of application, and/or path of application of the material to be applied. The ultrasonic vision device can also be used to detect a residual film or coating to verify its presence in the appropriate locations prior to applying another material over the residual coating.
[0022] Referring now to FIG. 3 , if even greater production rates are required, the illustrated configuration is estimated to provide a production rate of approximately 130 jobs per hour. The operation and configuration of the workstation illustrated in FIG. 3 is identical to that previously described for FIGS. 1 and 2 with the exception of a four station index table 44 is provided in place of the two station index table 42 illustrated in FIG. 2 . The four station index table can be provided with continuous rotation to move a part loaded into a first nest at a loading station to a first processing station, where a first robot or other material application equipment 22 a applies a first material layer to the workpiece along a desired path and in a desired sequence. While the workpiece in the first nest is being processed at the first processing station, a second nest is being loaded with a workpiece at the loading station. When the turntable rotates again, the workpiece in the first nest is delivered to a second processing station, while the workpiece in the second nest is delivered to the first processing station, and a third nest is positioned at the loading station for receiving another workpiece. The workpiece in the second nest is processed in the same manner as described for the workpiece in the first nest. The first nesting fixture now located at the second processing workstation is positioned within the work zone of a second robot or material application equipment 22 b. The second robot or material application equipment 22 b then applies a second material layer to the workpiece along the particular path and in the desired sequence for the particular workpiece as identified by the ultrasonic identification system. The ultrasonic identification system can determine whether the first material layer applied to the workpiece exists in the proper locations prior to application of the second material layer by the second robot or material application equipment 22 b. If the first material layer is absent or does not exist in the appropriate locations within the parameters set, the workpiece can be rejected prior to application of the material by the second material application equipment or robot 22 b. After completion of the processing at the first and second processing stations, and loading of a new part at the loading station into the third nesting fixture, the turntable can incrementally move the workpieces to the next workstation. In this position, the first nesting fixture and the workpiece located thereon is located at an unloading station where a workstation operator can remove the workpiece from the first nesting fixture for transport by the assist fixture along the rail and bridge to an appropriate workpiece storage rack 12 . The workpiece located in the second nesting fixture has been moved from the first processing station to the second processing station for application of the second material layer. The workpiece located in the third nesting fixture has moved from the loading station to the first processing station for application for the first material layer by the first mater equipment or robot 22 a. A fourth nesting fixture is now located at the loading station, where a workstation operator can remove an uncoated workpiece from an appropriate storage rack 12 for positioning using the assist fixture for movement along the rail and ridge to locate the workpiece in the fourth nesting fixture. While the configuration illustrated in FIG. 3 depicts a turntable configuration, it should be recognized by the those skilled in the art that workpieces can be moved between the four stations by any appropriate workpiece conveyor system known to those skilled in the art.
[0023] Referring now to FIG. 4 , the present invention includes a process for applying a layer of material to a workpiece for a vehicle. The process can include the step 100 of identifying a pattern, a size, and/or a shape of a workpiece to be processed. The identification can be performed by any suitable process known to those skilled in the art, such as operator input, bar code scanning, vision system scanning, and/or ultrasonic scanning. In the preferred configuration, identification of the workpiece can be accomplished with ultrasonic verification of the pattern, size, and/or shape of a workpiece. Based on the identification of the workpiece, the process continues to step 102 where the appropriate material is selected for application to the particular identified workpiece, the application sequence of the material is selected based on the identification of the workpiece to be processed, and/or the path of the material application equipment or robot is selected based on the identification of the workpiece. After selection of the appropriate material, sequence, and/or path, the process continues to query 104 where it is determined ultrasonically whether a residual pre-primer film is detected on a surface of the workpiece to be processed. If the residual pre-primer film is not detected ultrasonically on a surface of the workpiece, the process branches to step 106 where the workpiece is rejected. If the residual pre-primer film is ultrasonically detected on a surface of the workpiece, the process continues to step 108 where the material application equipment or robot applies a primer material layer over the residual film in preparation for subsequent application of a urethane sealant material layer. The process can then continue to step 110 where the material application equipment or robot can apply a urethane sealant material layer over the primer material layer previously applied. In other words, the process according to the present invention can include the steps of ultrasonically verifying a residual film from a first material layer previously applied to a surface of a workpiece, and if verified, applying a second material layer over the first material layer on the surface of the workpiece. The process can also include applying the first material layer to at least a portion of the surface of the workpiece using the material application equipment or robot at a workstation, and drying the first material layer to form a clear transparent surface. The first material layer can be provided as a pre-primer material for application to a least a portion of the surface of a workpiece. The process according to the present invention can also include applying a third material layer over the second material layer previously applied to the surface of a workpiece. The third material layer can be provided as a urethane sealant material for application to at least a portion of the surface of the workpiece. The second material layer can be provided as a primer material application to at least a portion of the surface of the workpiece.
[0024] The workpiece according to the present invention can include a contoured glass member defining the workpiece to be processed. A pre-primer material can be applied to at least a portion of the contoured glass member. The first material layer can be dried to form a clear transparent surface. A primer material can be provided for application on top of the first material layer located on the surface of the workpiece. A urethane sealant material can also be provided for application on top of the primer material layer located on the surface of the workpiece.
[0025] While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiments but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims, which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures as is permitted under the law. | An apparatus and process for applying a material layer to a workpiece for a vehicle can include ultrasonically verifying a residual film from a first material layer previously applied to a surface of a workpiece, and verified, applying a second material layer over the first material layer on the surface of the workpiece. The first material layer can include a pre-primer material. The pre-primer material layer can be dried to form a clear transparent surface. The second material layer can include a primer material for application to the pre-primer material layer previously applied to the surface of the workpiece to be treated. A urethane sealant material can then be applied to the primer material layer previously applied to the surface of the workpiece. The workpiece can include a contour class member for a vehicle, such as a front window, rear window, or side window, and/or roof window. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention disclosed herein relates to well logging tools and, in particular, to an improved light source and light detector for well logging tools.
2. Description of the Related Art
In exploration for hydrocarbons, it is important to male accurate measurements of properties of geologic formations. In particular, it is important to determine the various properties with a high degree of accuracy so that drilling resources are used efficiently.
Generally, oil and gas are accessed by drilling a borehole into the subsurface of the earth. The borehole also provides access for talking measurements of the geologic formations.
Well logging is a technique used to take measurements of the geologic formations from the boreholes. In one embodiment, a “logging tool” is lowered on the end of a wireline into the borehole. The logging tool sends data via the wireline to the surface for recording. Output from the logging tool comes in various forms and may be referred to as a “log.” Many types of measurements are made to obtain information about the geologic formations. One type of measurement involves determining gravitational acceleration or gravity.
Measurements of gravity can be used to determine information related to the mass of a surrounding formation. For example, measurements of gravity can be used to measure depletion of oil in the surrounding formation as water replaces the oil. When water replaces oil in the formation, the mass of the formation and, therefore, a gravitational force exerted by the formation will increase because water is denser than oil.
Measurements of gravity can also be used to determine true vertical depth in the borehole. The true vertical depth is important to know because borehole depth is a common factor among various logs. The various logs may be viewed side-by-side to form a composite picture of the geologic formations. Even small errors in determining the borehole depth can corrupt logging data. Horizontal deviations of the borehole, which can corrupt the logging data, can be accounted for by determining the true vertical depth using gravitational measurements.
A logging tool used for measuring gravity may employ a gravimeter that relates changes in gravitational acceleration to changes in light. This type of gravimeter requires a light source and a light detector. In order to obtain accurate measurements, it is important for the light source and the light detector to operate in a stable manner in the environment of the borehole.
In general, temperature in the borehole increases with increasing depth. In some instances, the temperature can be as high as 260° C. Additionally, the light source and the light detector may be subject to shocks of acceleration while traversing the borehole. To survive the rigors of the borehole environment, the light source and the light detector can be built using solid state technology. For example, the light source may include a laser diode and the light detector may include a photodiode.
Accurate measurements usually require that the wavelength of light emitted from the laser diode not shift more than ten ppm. In addition, the intensity of the light emitted from the laser diode should remain constant. With respect to the photodiode, the output should also remain stable for a stable input of light. With increasing temperature, the intensity of the light emitted from a laser diode decreases and the wavelength of the light increases to longer wavelengths. At high enough temperatures, such as temperatures within the borehole, most conventional laser diodes stop working. Providing stable laser light wavelength generally requires that the temperature of the conventional laser diode be maintained to within 0.001° C. Maintaining temperatures with this accuracy can be difficult in the borehole environment.
Therefore, what are needed are a light source and a light detector that can operate throughout a range of high temperatures and require less-stringent temperature control.
BRIEF SUMMARY OF THE INVENTION
Disclosed is an embodiment of an instrument for measuring gravitational acceleration from within a borehole, the instrument including: a light source having a semiconductor that comprises a bandgap greater than about two electron volts (eV); and a gravimeter for receiving light from the light source and providing output light with a characteristic related to the gravitational acceleration, the gravimeter implemented by at least one of a nano electromechanical system (NEMS) and a micro electromechanical system (MEMS); wherein the light source and the gravimeter are disposed in a housing adapted for insertion into the borehole.
Also disclosed is one example of a method for measuring gravitational acceleration from within a borehole, the method including: placing a light source and a gravimeter in the borehole, the light source having a semiconductor that has a bandgap greater than about two electron volts (eV), the gravimeter implemented by at least one of a nano electromechanical system (NEMS) and a micro electromechanical system (MEMS); and illuminating the gravimeter with light emitted from the light source wherein the light is used to perform the measuring.
Further disclosed is an embodiment of a system for measuring gravitational acceleration from within a borehole, the system including: a logging tool; a light source having a semiconductor that has a bandgap greater than about two electron volts (eV); a gravimeter for diffracting light emitted from the light source, the diffracted light having an intensity related to the gravitational acceleration, the gravimeter implemented by at least one of a nano electromechanical system (NEMS) and a micro electromechanical system (MEMS); a light detector having a semiconductor that has a bandgap greater than about two eV, the light detector for measuring the intensity; and a data collector for providing measurement data to a user.
BRIEF DESCRIPTION OF THE DRAWINGS
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, wherein like elements are numbered alike, in which:
FIG. 1 illustrates an exemplary embodiment of a logging tool in a borehole penetrating the earth;
FIG. 2 illustrates aspects of an exemplary embodiment of a light source, an optical filter and a light detector;
FIGS. 3A and 3B , collectively referred to as FIG. 3 , illustrate an exemplary embodiment of a gravimeter;
FIGS. 4A and 4B , collectively referred to as FIG. 4 , present graphs depicting an effect of the optical filter;
FIG. 5 illustrates an exemplary embodiment of a fiber Bragg grating;
FIG. 6 illustrates an exemplary embodiment of an optical cavity;
FIG. 7 illustrates an exemplary embodiment of a computer coupled to the logging tool; and
FIG. 8 presents one example of a method for measuring gravitational acceleration from within the borehole.
DETAILED DESCRIPTION OF THE INVENTION
The teachings provide techniques for measuring gravitational acceleration from within a borehole. In particular, the techniques provide for stable measurements of gravitational acceleration with varying temperatures within the borehole.
Gravitational acceleration is measured using a gravitational accelerometer, also referred to as a “gravimeter.” The gravimeter receives light and alters the light in accordance with an amount of gravitational acceleration sensed by the gravimeter.
The techniques include a light source for emitting light to the gravimeter. The light has a wavelength and an intensity that are stable over a range of temperatures to which the light source is exposed. In addition, the techniques provide a light detector that generates an output that is stable over a range of temperatures to which the light detector is exposed. Stability of the light source and stability of the light detector are provided by using semiconductors that include wide bandgap materials in conjunction with achievable temperature control. A narrower range of wavelengths, achieved using the wide band gap materials, results in more accurate measurements of gravitational acceleration than would occur if wavelength was allowed to drift by more than 10 ppm.
For convenience, certain definitions are provided. The term “gravimeter” relates to a sensor for measuring gravitational acceleration. The sensor receives light from a light source and relates a change in gravitational acceleration to a change in characteristics of light emitted from the sensor. Absolute gravitational acceleration can be measured with the gravimeter by relating the change in gravitational acceleration to a reference calibration point. The term “stable” relates to an output or parameter of a device that does not vary significantly with respect to an application. The term “light source” relates to a device that emits light for use in a sensor. In accordance with the teachings herein, the light source is maintained stable in a downhole environment. The term “light detector” relates to a device that generates an output (referred to as “photocurrent”) in relation to the power of light (referred to as “incident light power”) entering the device. The term “responsivity” refers to the ratio of generated photocurrent to the incident light power. In accordance with the teachings herein, the responsivity of a light detector made with wide bandgap materials is stable over a range of temperatures of interest to a user. The range of temperatures includes those temperatures that may be encountered by the logging tool in the borehole.
The term “bandgap” relates to an energy difference between the top of a valence band and the bottom of a conduction band in a semiconductor. Electrons in the conduction band are generally free to move to create an electrical current. Generally, only electrons, which have enough thermal energy to be excited across the bandgap, are available for conduction.
The term “housing” relates to a structure of a logging tool. The housing may used to at least one of contain and support a device used with the logging tool. The device may be at least one of the light source, the optical filter, and the light detector.
Referring to FIG. 1 , one embodiment of a well logging tool 10 is shown disposed in a borehole 2 . The logging tool 10 includes a housing 8 adapted for use in the borehole 2 . The borehole 2 is drilled through earth 7 and penetrates formations 4 , which include various formation layers 4 A- 4 E. The logging tool 10 is generally lowered into and withdrawn from the borehole 2 by use of an armored electrical cable 6 or similar conveyance as is known in the art. In the embodiment of FIG. 1 , an instrument 5 for measuring gravitational acceleration is disposed within the housing 8 . Also depicted in FIG. 1 is an electronic unit 9 , which receives and processes output data from the instrument 5 .
In some embodiments, the borehole 2 includes materials such as would be found in oil exploration, including a mixture of liquids such as water, drilling fluid, mud, oil and formation fluids that are indigenous to the various formations. One skilled in the art will recognize that the various features as may be encountered in a subsurface environment may be referred to as “formations.” Accordingly, it should be considered that while the term “formation” generally refers to geologic formations of interest, that the term “formations,” as used herein, may, in some instances, include any geologic points of interest (such as a survey area).
For the purposes of this discussion, it is assumed that the borehole 2 is vertical and that the formations 4 are horizontal. The teachings herein, however, can be applied equally well in deviated or horizontal wells or with the formation layers 4 A- 4 E at any arbitrary angle. The teachings are equally suited for use in logging while drilling (LWD) applications, measurement while drilling (MWD) and in open-borehole and cased-borehole wireline applications. In LWD/MWD applications, the logging tool 10 may be disposed in a drilling collar. When used in LWD/MWD applications, drilling may be halted temporarily to prevent vibrations while the logging tool 10 is used to perform a measurement.
FIG. 2 illustrates aspects of an exemplary embodiment of the instrument 5 that includes a light source 20 , an optical filter 22 , a gravimeter 24 and a light detector 26 . Referring to FIG. 2 , the light source 20 provides emitted light 21 to the optical filter 22 . The optical filter 22 filters the emitted light 21 and provides filtered light 23 to the gravimeter 24 . Generally, the filtered light 23 has a narrower range of wavelengths (and corresponding frequencies) than the emitted light 21 . The gravimeter 24 receives the filtered light 23 and provides output light 25 to the light detector 26 . The light detector 26 is used to measure at least one of intensity, frequency, and angle of the output light 25 .
The gravimeter 24 may be built using solid state fabrication techniques to survive the environment of the borehole 2 . Solid state fabrication also results in the gravimeter 24 having dimensions small enough to fit within the housing 8 . In one embodiment, the gravimeter 24 is implemented by at least one of a Nano Electromechanical System (NEMS) and a Micro Electromechanical System (MEMS) as is known to those skilled in the art of NEMS and MEMS. In this embodiment, a proof mass is used to measure gravitational force. The proof mass is coupled to a diffraction grid such that at least one dimension of the diffraction grid changes with displacement of the proof mass. The diffraction grid is used along with the light source 20 and the light detector 26 to act as an interferometric displacement sensor. The filtered light 23 may be diffracted by the diffraction grid to provide the output light 25 . Characteristics of the output light 25 can be measured by the light detector 26 and correlated to the displacement of the proof mass to determine the gravitational force. By knowing the mass of the proof mass and the gravitational force, the gravitational acceleration can be determined. The filtered light 23 with stable characteristics and a narrow range of wavelengths can provide for improved accuracy in gravitational measurements. Similarly, the light detector 26 with stable responsivity can also provide for improved accuracy in the gravitational measurements.
FIG. 3 illustrates an exemplary embodiment of the gravimeter 24 that is implemented by at least one of a NEMS and a MEMS. A top view of the gravimeter 24 is depicted in FIG. 3A . Referring to FIG. 3A , the gravimeter 24 includes a proof mass 30 coupled to a diffraction grid 31 . The proof mass 30 is suspended by springs 32 coupled to a support substrate 33 . The springs 32 provide a counter-force to the force of gravity while allowing displacement of the proof mass 30 due to the force of gravity. In the embodiment depicted in FIG. 3A , the proof mass 30 , the diffraction grid 31 , and the springs 32 are implemented by at least one of the NEMS and the MEMS.
FIG. 3B illustrates a side view of the gravimeter 24 . FIG. 3B depicts the gravimeter 24 with the light source 20 , the optical filter 22 , and the light detector 26 . The diffraction grid 31 , the light source 20 , the optical filter 22 , and the light detector 26 form an interferometric displacement sensor 34 . Referring to FIG. 3B , the springs 32 allow movement of the proof mass 30 in substantially vertical direction 35 . As the proof mass 30 moves, at least one dimension defining the diffraction grid 31 changes. In turn, intensity of the output light 25 is related to the at least one dimension. Thus, by measuring the intensity, displacement of the proof mass 30 can be determined. Further, the displacement can be correlated to an amount of gravitational force or gravitational acceleration imposed on the proof mass 30 .
Wide band gap materials are used to make the light source 20 and the light detector 26 . The wide bandgap materials provide stability for the light source 20 and the light detector 26 throughout a range of temperatures. Thermally generated electrons and holes can increase noise and change the wavelength (and corresponding frequency) of the emitted light 21 . Similarly, the thermally generated electrons and holes can increase noise and reduce response of the light detector 26 . By using the wide bandgap materials, the number of electrons and holes that are thermally excited to the conduction band is significantly reduced. Reducing the number of thermally excited electrons and holes in the conduction band results in the emitted light 21 having a stable wavelength and the light detector 22 having a stable responsivity. In addition, a reduction of thermally excited electrons and holes in the conduction band results in decreased noise in the light source 20 and the light detector 26 .
The color of a light ray or photon corresponds to the wavelength and the associated energy of the photon. For example, blue light has a wavelength of 450 nanometers (nm) and a photon energy of about 2.76 electron volts (eV). The wide bandgap materials are associated with light towards the blue end of the light spectrum. Generally, semiconductors having wide bandgaps emit or respond to photons that have an energy corresponding to the energy of the bandgap. Thus, the light source 20 and the light detector 26 that are associated with light towards the blue end of the light spectrum provide for improved thermal behavior.
Many types of the wide bandgap materials may be used to build the light source 20 and the light detector 26 . Examples of the wide bandgap materials include Gallium Phosphide (GaP), Gallium Nitride (GaN), and Silicon Carbide (SiC). With the exception of GaP (550 nm wavelength), these wide bandgap materials emit or respond to light in the ultraviolet range (100 nm-400 nm).
Recently developed wide bandgap (e.g. 405 nm) laser diodes can operate at higher temperatures than conventional laser diodes. The wide bandgap laser diodes have less wavelength shift with temperature (0.05 nm/° K) than the conventional laser diodes. A wavelength shift of 0.05 nm/° K corresponds to wavelength stability of 123 ppm/° C. Therefore, the wide band gap laser diodes require temperature maintenance to within about 0.081° C. to achieve 10 ppm wavelength stability, which can be achieved downhole. Intensity of the light emitted from the wide band gap laser diodes can be maintained by adjusting the current through the wide band gap laser diodes. An exemplary embodiment of a wide band gap laser diode for use as the light source 20 is a blue violet laser diode (405 nm) model number DL-3146-151 manufactured by SANYO Electric Company, LTD of Tottori, Japan.
The optical filter 22 filters the emitted light 21 to provide the filtered light 23 with a narrow range of wavelengths. FIG. 4 presents graphs depicting the effect of the optical filter 22 on the emitted light 21 . FIG. 4A illustrates an exemplary graph 40 of intensity versus wavelength for the emitted light 21 . FIG. 4B illustrates an exemplary graph 41 of intensity versus wavelength for the filtered light 23 .
One embodiment of the optical filter 22 is a fiber Bragg grating as shown in FIG. 5 . The fiber Bragg grating forms an optical waveguide with at least one of periodic and aperiodic perturbations of the effective refractive index of a core of the waveguide. Referring to FIG. 5 , a fiber Bragg grating 50 includes a cladding 51 and a core 52 . Light is transmitted in the core 52 and reflected from the cladding 51 . The core 52 includes at least one of periodic and aperiodic perturbations 53 (or grating 53 ) of the effective refractive index of the core 52 as depicted in FIG. 5 . The effect of the grating 53 is that the fiber Bragg grating 50 can reflect a narrow range of wavelengths of light incident on the grating 53 , while passing all other wavelengths of the incident light. The result is that the filtered light 23 depicted in FIG. 5 has a narrower range of wavelengths than the emitted light 21 incident on the grating 53 .
Another embodiment of the optical filter 22 is a Fabry-Perot cavity. For optical channel separation, telecommunications Fabry-Perot cavity filters exist that are stable to within a picometer. Stability to within a picometer for a 405 nm light source corresponds to 2.5 ppm wavelength stability. A fiber Fabry-Perot tunable filter is available from Micron Optics Inc. of Atlanta, Ga.
FIG. 6 depicts a Fabry-Perot cavity 60 . Referring to FIG. 6 , the cavity 60 includes mirrored surfaces 61 and a spacer medium 62 in optical contact with the mirrored surfaces 61 . The emitted light 21 entering the cavity 60 will reflect multiple times from the mirrored surfaces 61 . Only certain wavelengths of the emitted light 21 will be sustained by the cavity 60 . The other wavelengths of the emitted light 21 will be suppressed by destructive interference. The result is that the filtered light 23 depicted in FIG. 6 has a narrower range of wavelengths than the emitted light 21 incident on the cavity 60 .
Generally, the wavelengths of the light sustained by the cavity 60 are determined by a distance, D, between the mirrored surfaces 61 as shown in FIG. 5 . In some embodiments, the cavity 60 can be built using solid state technology such as that used to fabricate semiconductor devices. Fabricating the Fabry-Perot cavity 60 using solid state technology provides a cavity in which light is reflected many times before dissipating. Thus, a solid state Fabry-Perot cavity 60 is efficient in providing light with a narrow bandwidth.
In order to provide the filtered light 23 with little or no variations in the narrow range of wavelengths throughout a range of temperatures, the fiber Bragg grating 50 and the Fabry-Perot cavity 60 may be built using glass having a low coefficient of thermal expansion to achieve 0.01 ppm stability in wavelength. The glass may be referred to as “low expansion glass.” In one embodiment of the fiber Bragg grating 50 , the core 52 is made from low expansion glass. In one embodiment of the Fabry-Perot cavity 60 , the spacer medium 62 is made from low expansion glass. The coefficient of thermal expansion for the low expansion glass used in embodiments of the optical filter 22 can be less than 0.2 ppm/° K over a range of temperatures in the borehole 2 . One example of low expansion glass is ULE® glass manufactured by Coming Specialty Materials of Corning, N.Y. Another example of low expansion glass is ZERODUR® glass manufactured by Schott AG of Mainz, Germany.
Generally, the well logging tool 10 includes adaptations as may be necessary to provide for operation during drilling or after a drilling process has been completed.
Referring to FIG. 7 , an apparatus for implementing the teachings herein is depicted. In FIG. 7 , the apparatus includes a computer 70 coupled to the well logging tool 10 . Typically, the computer 70 includes components as necessary to provide for the real time processing of data from the well logging tool 10 . Exemplary components include, without limitation, at least one processor, storage, memory, input devices, output devices and the like. As these components are known to those skilled in the art, these are not depicted in any detail herein.
Generally, some of the teachings herein are reduced to an algorithm that is stored on machine-readable media. The algorithm is implemented by the computer 60 and provides operators with desired output. The output is typically generated on a real-time basis.
The logging tool 10 may be used to provide real-time measurements of various parameters such as gravity for example. As used herein, generation of data in “real-time” is taken to mean generation of data at a rate that is useful or adequate for making decisions during or concurrent with processes such as production, experimentation, verification, and other types of surveys or uses as may be opted for by a user or operator. As a non-limiting example, real-time measurements and calculations may provide users with information necessary to make desired adjustments during the drilling process. In one embodiment, adjustments are enabled on a continuous basis (at the rate of drilling), while in another embodiment, adjustments may require periodic cessation of drilling for assessment of data. Accordingly, it should be recognized that “real-time” is to be taken in context, and does not necessarily indicate the instantaneous determination of data, or make any other suggestions about the temporal frequency of data collection and determination.
A high degree of quality control over the data may be realized during implementation of the teachings herein. For example, quality control may be achieved through known techniques of iterative processing and data comparison. Accordingly, it is contemplated that additional correction factors and other aspects for real-time processing may be used. Advantageously, the user may apply a desired quality control tolerance to the data, and thus draw a balance between rapidity of determination of the data and a degree of quality in the data.
FIG. 8 presents one example of a method 80 for measuring gravitational acceleration from within the borehole 2 . The method 80 calls for placing (step 81 ) the light source 20 and the gravimeter 24 in the borehole 2 . Further, the method 80 calls for illuminating (step 82 ) the gravimeter 24 with light emitted from the light source 20 wherein the light is used to perform the measuring.
In certain embodiments, a string of two or more logging tools 10 may be used where each logging tool 10 includes at least one light source 20 , the optical filter 22 and the light detector 26 . In these embodiments, a response from each logging tool 10 may be used separately or combined with other responses to form a composite response.
In support of the teachings herein, various analysis components may be used, including digital and/or analog systems. The digital and/or analog systems may be used in the electronic unit 9 . In one embodiment, the electronic unit 9 may be a data collector (data collector 9 ) for providing measurement data to a user. The electronic unit 9 may be disposed at least one of in the logging tool 10 and at the surface of the earth 7 . The system may have components such as a processor, storage media, memory, input, output, communications link (wired, wireless, pulsed mud, optical or other), user interfaces, software programs, signal processors (digital or analog) and other such components (such as resistors, capacitors, inductors and others) to provide for operation and analyses of the apparatus and methods disclosed herein in any of several manners well-appreciated in the art. It is considered that these teachings may be, but need not be, implemented in conjunction with a set of computer executable instructions stored on a computer readable medium, including memory (ROMs, RAMs), optical (CD-ROMs), or magnetic (disks, hard drives), or any other type that when executed causes a computer to implement the method of the present invention. These instructions may provide for equipment operation, control, data collection and analysis and other functions deemed relevant by a system designer, owner, user or other such personnel, in addition to the functions described in this disclosure.
Further, various other components may be included and called upon for providing for aspects of the teachings herein. For example, a power supply (e.g., at least one of a generator, a remote supply and a battery), cooling unit, heating unit, sensor, transmitter, receiver, transceiver, antenna, controller, lens, optical unit, electrical unit or electromechanical unit may be included in support of the various aspects discussed herein or in support of other functions beyond this disclosure.
It will be recognized that the various components or technologies may provide certain necessary or beneficial functionality or features. Accordingly, these functions and features as may be needed in support of the appended claims and variations thereof, are recognized as being inherently included as a part of the teachings herein and a part of the invention disclosed.
While the invention has been described with reference to exemplary embodiments, it will be understood that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications will be appreciated to adapt a particular instrument, situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims. | An instrument for measuring gravitational acceleration from within a borehole, the instrument including: a light source having a semiconductor that comprises a bandgap greater than about two electron volts (eV); and a gravimeter for receiving light from the light source and providing output light with a characteristic related to the gravitational acceleration, the gravimeter implemented at least one of a nano electro-mechanical system (NEMS) and a micro electro-mechanical system (MEMS); wherein the light source and the gravimeter are disposed in a housing adapted for insertion into the borehole. | 4 |
[0001] This application claims the benefit of U.S. Provisional Application No. 61/573,205 filed Aug. 17, 2011
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to smart control of electronic roadside billboards and is targeted to maximize the value of advertisements presented on electronic roadside billboards by choosing the best advertisement for the population viewing the advertisements.
[0004] 2. Background Art
[0005] Roadside billboard are extensively used for effective advertisement all over the world. Traditional roadside billboards are placed at strategic viewing locations and display large pictorial advertisements, printed or painted on paper, cloth, wood, plastic or any other material that is held by a supporting frame. Recently new type of billboards, electronic roadside billboards, are extensively installed, either as a replacement of existing traditional billboards or as newly placed billboards.
[0006] Instead of printed or painted advertisements, electronic roadside billboards display images, graphics or videos on light-emitting electronic displays. Construction and placement of electronic roadside billboards is considerably more expensive than the construction and placement of traditional roadside billboards. However, electronic roadside billboards can provide significant advertisement advantages and, assuming a reliable long-term operation, might be cheaper to operate in the long run.
[0007] A first advantage in using electronic roadside billboards is the simplicity and speed of changing or updating an advertisement. Change of advertisement in traditional roadside billboards requires the physical painting or printing of the advertisement material and the manual labor of removing an old advertisement and replacing it with the newly prepared advertisement. On the other hand, advertisements on electronic roadside billboards can be changed or updated simply and rapidly by electronically sending the new advertisement image, graphics or video to the electronic roadside billboards.
[0008] A second advantage of using electronic roadside billboards is the ability to display dynamic advertisements, including rapidly changing images, moving graphics or video clips. (It should be noted that in many jurisdictions displaying of videos and even rapidly changing images or moving graphics is prohibited by law, to avoid drivers distraction and the risk of traffic accidents.)
[0009] Targeted advertisement, which addresses specific and relevant viewing population, is a key for modern and successful advertisement. Electronic roadside billboards allow easy and frequent changes of advertisements, but they cannot be used for targeted advertisement since the viewing population of the displayed advertisements is unknown and therefore it is impossible to select the best advertisement for the viewing population. (The viewing population might only be anticipated by some general factors, such as the billboard location, hour of the day, local weather or local events.) Therefore, there is a need for an approach to provide more accurate information about the viewing population that is traveling by the electronic roadside billboards and therefore is likely to notice and be influenced by the displayed advertisements. This information may allow selecting and displaying, at any moment in time, the most suitable advertisement for the particular viewing population and therefore to maximize the effective value of the displayed advertisements.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The features and advantages of the present invention will become more readily apparent to those ordinarily skilled in the art after reviewing the following detailed description and accompanying drawings, wherein:
[0011] FIG. 1 illustrates a schematic diagram of a conventional roadside billboard.
[0012] FIG. 2 illustrates a schematic diagram of a smart electronic roadside billboard.
[0013] FIG. 3 illustrates a general flowchart of the operations of a smart electronic roadside billboard.
DETAILED DESCRIPTION OF THE INVENTION
[0014] The present invention is directed to a smart electronic roadside billboard system, which captures and analyzes visual information (such as pictures or videos) to provide information on a viewing population of travelers that pass through an effective viewing area for an electronic roadside billboard, and that selects an advertisement that is most suitable and effective (in some sense) for that viewing population. Although the invention is described with respect to specific embodiments, the principles of the invention can obviously be applied beyond the specifically described embodiments of the invention described herein. Moreover, in the description of the present invention, certain details have been left out in order to not obscure the inventive aspects of the invention. The details left out are within the knowledge of a person of ordinary skill in the art.
[0015] The drawings in the present application and their accompanying detailed description are directed to merely example embodiments of the invention. To maintain brevity, other embodiments of the invention which use the principles of the present invention are not specifically described in the present application and are not specifically illustrated by the present drawings. It should be borne in mind that, unless noted otherwise, like or corresponding elements among the figures may be indicated by like or corresponding reference numerals.
[0016] FIG. 1 shows a schematic diagram of a conventional (or electronic) roadside billboard 100 . The billboard is commonly placed near a curve in the road 102 , which provides the best viewing conditions (the effective viewing area) for the people that travel in the cars 104 .
[0017] FIG. 2 shows a schematic diagram of a smart electronic roadside billboard 200 . Similar to the conventional roadside billboard 100 , it is also commonly placed near a curve in the road 102 , which provides the best viewing conditions for the people that travel in the cars 104 . However, the smart electronic roadside billboard includes a camera 202 and a control unit 204 . The camera can be a video camera or a still camera. The camera captures visual information such as pictures or videos of the cars advancing toward the smart electronic roadside billboard and provides the pictures, videos, or other information to the control unit. In the most likely configuration the camera may be placed at some distance before the smart electronic road billboard, which means that it may capture pictures or videos of cars that will arrive later to the effective viewing area of the smart electronic road billboard. In another possible configuration several cameras may be placed at different locations and angles to capture more than one picture or one video of the passing cars. The visual information will consist of all pictures and videos captured by all cameras. Moreover, one or more cameras may operate at an electromagnetic spectrum which is not visible by human, such as infrared of ultraviolet wavelengths, wherein the visual information will also consist on the pictures or videos obtained by cameras using such out-of-visible-light spectrum.
[0018] The visual information, which is the digital representation of the pictures or videos captured by the camera or the multiple cameras, is processed by control unit 204 . The depiction of the control unit 204 in FIG. 2 is provided only as an example. In other configurations the processing may by distributed over several processing units or modules in different physical locations, including the camera-apparatuses themselves, a processing unit or several connected processing units dedicated to the smart electronic roadside billboard, or other processing units, local or remote, each carry part of the processing. The goal of the processing is to analyze and extract identification characteristics about the passing cars, about the passengers, items or pets traveling in the cars or any other useful information that may have a value in making an advertisement decision or that may assist in the operation of the smart electronic road billboard.
[0019] The identification characteristics for any car may include the make (manufacturing company) of the car (e.g., Honda, Toyota, Ford, etc.), the model of the car (e.g., Accord, Prius, Focus, etc.), the model-year of the car, the color of the car, the mechanical and exterior condition of the car, the traveling speed or the position of the car on the road (such as lanes, relative positions and distances from other cars), or any other identification characteristics about the car that may have a value in making an advertisement decision. In jurisdictions where permitted by law, the identification characteristics may include the license plate registration number of the car or any other information that identifies the car. The identification characteristics may include the number of passengers in the car, the age of any passenger in the cars, the gender of any passenger in the cars, the ethnic origin of any passenger in the car, or any other information about the passengers in the car that can have a value in making an advertisement decision. (A passenger is a person in the car that is the driver of the car or any other person in the car in addition to the driver.) The identification characteristics may also include the presence of items in the car such as child seats, sport gear or technical gadgets (e.g., smartphone, GPS unit, music player, tablet, etc.), or any other information about any item in the car that may have a value in making an advertisement decision. The identification characteristics may include the presence of any pet in the cars and the species and breed of any pet (a pet traveling in a car will most likely be a dog), or any other information about any pet in the car that can have a value in making an advertisement decision.
[0020] The process of extracting the identification characteristics from the visual information is commonly called scene analysis. Scene analysis is a well known concept of using analytically and heuristically-formed algorithms to extract various characteristics from the visual information. It can use many concepts and multiple processing tools in numerous stages. For example, during day light, the car make, model and model-year may be identified by matching any car structural features contained in the visual information (e.g., shapes of windows, doors, front grills, wheels, roofs or trunks, or any other structural element of any car) to a pre-stored database of car structural features. At night time, on the other hand, any car identification characteristics may be based on matching any light emitting elements contained in the visual information (e.g., head, tail, break, signaling or other lights) to a pre-stored database of car light emitting elements (such as relative positions, shape, or spectral attributes). In another example, during day time the identification characteristics of a passenger in the car such as age, gender or ethnic background may be extracted by examining body and facial parameters, which may consist of estimated height and weight, hair style and color, skin texture and tone, lips structuring and coloring, as well as by examining the clothes the passengers are wearing. During night time the number of passengers in the cars and other identification characteristics of any passenger in any car may be estimated using infrared imaging. Items in the car, such as child seats, sport gear or technical gadgets or any other items in any car may be identified by matching their structural features to a pre-stored database of structural features of such items. In yet another example, any pet traveling in any car may be identified and its species and breed may be determined by analyzing the pet size, shape, color or facial features.
[0021] The identification characteristics are collected and analyzed to make a decision on which advertisement to display at each time, with the goal of choosing the best advertisements to maximize the advertisement value to the viewing population. The advertisements to be displayed may be stored locally or in a remote location for transmission to the smart electronic roadside billboard via a communication link (not shown in FIG. 2 ), based on the decision made by the local processing unit or units, or by making the advertisement decision at a remote location.
[0022] The decision on which advertisement to display may be made using several criteria. One criteria can be a value of a parameter. For example, upon finding a significantly higher ratio of female passengers to male passengers (or vice verse) traveling in the cars approaching the smart electronic roadside billboard, an advertisement that has a higher value for female viewers may be selected to be displayed on the smart electronic roadside billboard (or vice versa, if there are more male passengers than female passengers). In another example, the choice of the advertisement may be based on several parameters, which together are used to make a decision on displaying a specific advertisement on the smart electronic roadside billboard. For example, upon the detection of several luxury cars with children traveling in these luxury cars, the selected advertisements might be for luxury toys, children vacations or other advertisements targeted for high-income families with children.
[0023] The decision may be made using any of the identification characteristics, and may be made based on the statistical properties of the identification characteristics, such as averages, maxima, outliers, or any other function derived from the identification characteristics. The decision may be based on a pre-set criteria, which may be set according to advertisement and marketing researches, in order to display an advertisement that is considered to have the highest marketing value for the viewing population traveling in the cars as they approach the smart electronic roadside billboard. Moreover, the decision of which advertisement to display at each time can also consider some other general factors, which may include the location of the electronic billboard, hour of the day, local (or regional) weather conditions, or particular promotional and sale events.
[0024] It is important to note that it will be sufficient to extract only some of the identification characteristics for some of the cars or some of the passengers, items or pets traveling in the cars for a successful implementation of this invention. Based on the positions of the cameras, the light conditions, the weather conditions or any other factor that might limit the capturing or the analysis of the visual information, it is possible that only some of the identification characteristics of only some of the cars, as well as of only some of the passengers, items or pets in the cars, will be successfully extracted. Of course, the decision on which advertisement to use will likely improve as the system is able to obtain more of the identification characteristics of the cars and the passengers, items or pets in the cars.
[0025] FIG. 3 provides a general flowchart of the operations of a smart electronic roadside billboard. At step 300 , the visual information of the cars approaching the smart electronic roadside billboard is captured. The visual information may be captured by a single camera or by several cameras, which may be still cameras or video cameras. The visual information may be in wavelengths visible by a human eye, or in wavelengths invisible to a human eye, such as infrared or ultraviolet lights. The visual information is the digital representation of the pictures and/or the videos captured by the cameras. At step 302 identification characteristics are extracted from visual information, which may be done by a variety of scene analysis algorithms, The scene analysis results in identification characteristics for the cars and the passengers traveling in the cars, as well as items and pets that might be in the cars. The identification characteristics are then used in step 304 to make a decision on the advertisement that will be displayed on the smart electronic roadside billboard. The advertisement is selected to maximize the advertisement value for the viewing population that will be traveling through the effective viewing area when the advertisement is displayed. The selected advertisement is then displayed on the electronic display of the smart electronic roadside billboard at step 306 .
[0026] The processing is repeated for the next group of cars that will be approaching the effective viewing area and results in the selection of a new advertisement for this next group. The time-period of showing each advertisement may depend on several factors. One factor may be the size of the effective viewing area, which is the area where the viewing population can effectively view the smart electronic roadside billboard. For example, a billboard on a curve at the end of long straight stretch of a road will have a large effective viewing area and therefore each advertisement can be displayed longer than for a billboard with a smaller effective viewing area. In another example, a billboard at an intersection may synchronize the change of advertisements with the traffic lights in the intersection. Notably, another critical factor for the rate of change for advertisements might be the legal restrictions for such rate of change for electronic billboards in specific jurisdictions.
[0027] The processing in FIG. 3 is depicted as a sequential processing, but it may also be done in parallel by different processing modules. For example, at the same time that the electronic display is displaying the advertisement for one group of cars that are currently traveling through the effective viewing area, the control unit may be completing the extracting of the identification parameters and the selecting of the advertisement for the next group of cars, while the cameras may be capturing the visual information for a further next group of cars. | There is provided a method for selecting an advertisement to be displayed on a smart electronic roadside electronic billboard. The method comprises capturing visual information of cars traveling on a road and using the visual information to extract identification characteristics about the cars, passengers in the cars, as well as items or pets that might be in the cars. The method further comprises using the identification characteristics to select an advertisement to be displayed on the smart electronic roadside electronic billboard, such that the selected advertisement maximizes the advertisement value. The method may further comprises using other general factors and timing considerations in selecting and displaying an advertisement. The method may be implemented by an apparatus comprising of at least one camera that captures the visual information and at least one control unit that extracts the identification characteristics from the visual information and use the identification characteristics to select the advertisement to be displayed on the smart electronic roadside electronic billboard. | 6 |
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application is a continuation of, claims priority to, and incorporates by reference herein in its entirety, pending U.S. patent application Ser. No. 10/920,104, filed 17 Aug. 2004, which claims priority to U.S. Provisional Patent Application Ser. No. 60/497,782, filed 26 Aug. 2003.
BACKGROUND
[0002] Industrial automation has increased in scope and refinement with time. In general, industrial automation has focused on continuous processes comprising a plurality of interacting machines. Heretofore, automation has not fully developed using automation for process improvement relating to production and/or reliability related to discrete machines in certain applications.
[0003] United States Patent Application No. 20030120472 (Lind), which is incorporated by reference herein in its entirety, allegedly cites a “process for simulating one or more components for a user is disclosed. The process may include creating an engineering model of a component, receiving selection data for configuring the component from a user, and creating a web-based model of the component based on the selection data and the engineering model. Further, the process may include performing a simulation of the web-based model in a simulation environment and providing, to the user, feedback data reflecting characteristics of the web-based model during the simulation.” See Abstract.
[0004] United States Patent Application No. 20020059320 (Tamaru), which is incorporated by reference herein in its entirety, allegedly cites a “plurality of work machines is connected by first communication device such that reciprocal communications are possible. One or a plurality of main work machines out of the plurality of work machines are connected to a server by second communication device such that reciprocal communications are possible. Each work machine is provided with work machine information detection device for detecting work machine information. The server is provided with a database which stores data for managing the work machines, and management information production device for producing management information based on the work machine information and on data stored in the database. In conjunction with the progress of work by the plurality of work machines, work machine information is detected by the work machine information detection device provided in the work machines, and that detected work machine information is transmitted to the main work machine via the first communication device. The main work machine transmits the transmitted work machine information to the server via the second communication device.
[0005] The server produces management information, based on the transmitted work machine information and on data stored in the database, and transmits that management information so produced to the main work machine via the second communication device. The main work machine manages the work machines based on the management information so transmitted.” See Abstract.
SUMMARY
[0006] Certain exemplary embodiments can comprise obtaining and analyzing data from at least one discrete machine, automatically determining relationships related to the data, taking corrective action to improve machine operation and/or maintenance, automatically and heuristically predicting a failure associated with the machine and/or recommending preventative maintenance in advance of the failure, and/or automating and analyzing mining shovels, etc.
[0007] Certain exemplary embodiments comprise a method comprising at a remote server, receiving representative data obtained from a set of sensors associated with a machine, said representative data transmitted responsive to a transmission rate selected by a wirelessly receiving user; and storing said received representative data in a memory device.
[0008] Certain exemplary embodiments comprise a method comprising at an information device, receiving representative data from a memory device, said representative data generated by a set of sensors associated with a machine, said representative data transmitted responsive to a transmission rate selected by a wirelessly receiving user; and rendering at least one report responsive to said representative data.
[0009] Certain exemplary embodiments comprise receiving a plurality of values for a plurality of machine variables associated with one or more machine components; analyzing at least two variables from the plurality of machine variables, to determine a performance of the one or more machine components; and rendering a report that indicates the determined performance of the machine components
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] A wide variety of potential embodiments will be more readily understood through the following detailed description, with reference to the accompanying drawings in which:
[0011] FIG. 1 is a block diagram of an exemplary embodiment of a machine data management system 1000 ;
[0012] FIG. 2 is a flow diagram of an exemplary embodiment of a machine data management method 2000 ;
[0013] FIG. 3 is a flow diagram of an exemplary embodiment of a machine data management method 3000 ;
[0014] FIG. 4 is a block diagram of an exemplary embodiment of an information device 4000 ;
[0015] FIGS. 5 a , 5 b , and 5 c are an exemplary embodiment of a partial log file layout for data associated with a mining shovel;
[0016] FIG. 6 is an exemplary user interface showing a graphical trend chart of electrical data for a crowd motor of a mining shovel;
[0017] FIG. 7 is an exemplary user interface showing a graphical rendering of gauges displaying electrical data of a crowd motor of a mining shovel;
[0018] FIG. 8 is an exemplary user interface showing a relationship between speed and torque of a crowd motor of a mining shovel;
[0019] FIG. 9 is an exemplary user interface showing a graphical rendering of gauges displaying temperatures related to a mining shovel crowd;
[0020] FIG. 10 is an exemplary user interface showing information related to driver operation of a mining shovel;
[0021] FIG. 11 is an exemplary user interface showing a graphical trend chart of electrical data for a hoist motor of a mining shovel;
[0022] FIG. 12 is an exemplary user interface showing a graphical rendering of gauges displaying electrical data for a hoist motor of a mining shovel;
[0023] FIG. 13 is an exemplary user interface showing a relationship between speed and torque of a hoist motor of a mining shovel;
[0024] FIG. 14 is an exemplary user interface showing a graphical rendering of gauges displaying temperatures related to a mining shovel hoist;
[0025] FIG. 15 is an exemplary user interface showing a graphical trend chart of electrical data related to a mining shovel;
[0026] FIG. 16 is an exemplary user interface showing information related to mining shovel operations;
[0027] FIG. 17 is an exemplary user interface showing position information related to a mining shovel;
[0028] FIG. 18 is an exemplary user interface showing a graphical rendering of gauges displaying pressures of mining shovel components;
[0029] FIG. 19 is an exemplary user interface showing a graphical rendering of gauges displaying temperatures of mining shovel components;
[0030] FIG. 20 is an exemplary user interface showing a graphical rendering of gauges displaying electrical data of hoist, crowd, and swing motors of a mining shovel;
[0031] FIG. 21 is an exemplary user interface showing a graphical trend chart of motion data related to a mining shovel;
[0032] FIG. 22 is an exemplary user interface showing a graphical trend chart of production data related to a mining shovel;
[0033] FIG. 23 is an exemplary user interface showing a graphical rendering of gauges displaying production data of a mining shovel;
[0034] FIG. 24 is an exemplary user interface providing operating statuses of mining shovel components;
[0035] FIG. 25 is an exemplary user interface showing a graphical trend chart of electrical data for a swing motor of a mining shovel;
[0036] FIG. 26 is an exemplary user interface showing a graphical rendering of gauges displaying electrical data for a swing motor of a mining shovel;
[0037] FIG. 27 is an exemplary user interface showing a relationship between speed and torque of a swing motor of a mining shovel; and
[0038] FIG. 28 is an exemplary user interface showing a graphical rendering of gauges displaying temperatures related to a mining shovel swing.
DEFINITIONS
[0039] When the following terms are used herein, the accompanying definitions apply:
Active X—a set of technologies developed by Microsoft Corp. of Redmond, Wash. Active X technologies are adapted to allow software components to interact with one another in a networked environment, such as the Internet. Active X controls can be automatically downloaded and executed by a Web browser. activity—performance of a function. analogous—logically representative of and/or similar to. analysis—evaluation. automatic—performed via an information device in a manner essentially independent of influence or control by a user. communicate—to exchange information. communicative coupling—linking in a manner that facilitates communications. component—a part. condition—existing circumstance. connection—a physical and/or logical link between two or more points in a system. For example, a wire, an optical fiber, a wireless link, and/or a virtual circuit, etc. correlating—mathematically determining relationships between two or more non-time variables. For example, correlating can comprise a gamma association calculation, Pearson association calculation, tests of significance, linear regression, multiple linear regression, polynomial regression, non-linear regression, partial correlation, semi-partial correlation multicollinearity, suppression, trend analysis, curvilinear regression, exponential regression, cross-validation, logistic regression, canonical analysis, factor analysis, and/or analysis of variance techniques, etc. cycle time—a time period associated with loading a haulage machine with an electric mining shovel. data—numbers, characters, symbols etc., that have no “knowledge level” meaning. Rules for composing data are “syntax” rules. Data handling can be automated. database—one or more structured sets of persistent data, usually associated with software to update and query the data. A simple database might be a single file containing many records, each of which is structured using the same set of fields. A database can comprise a map wherein various identifiers are organized according to various factors, such as identity, physical location, location on a network, function, etc. detect—sense or perceive. determine—ascertain. deviation—a variation relative to a standard, expected value, and/or expected range of values. digging—excavating and/or scooping. dispatch data—information associated with scheduling personnel and/or machinery. dispatcher—a person, group of personnel, and/or software assigned to schedule personnel and/or machinery. For example, a dispatcher can schedule haulage machines to serve a particular electric mining shovel. earthen—related to the earth. electrical—pertaining to electricity. electrical component—a device and/or system associated with a machine using, switching, and/or transporting electricity. An electrical component can be an electric motor, transformer, starter, silicon controlled rectifier, variable frequency controller, conductive wire, electrical breaker, fuse, switch, electrical receptacle, bus, and/or transmission cable, etc. electrical performance—performance related to an electrical component of a machine. For example, electrical performance can relate to a power supply, power consumption, current flow, energy consumption, electric motor functionality, speed controller, starter, motor-generator set, and/or electrical wiring, etc. electric mining shovel—an electrically-powered device adapted to dig, hold, and/or move earthen materials. electric mining shovel component—a part of an electric mining shovel. A part of an electric mining shovel can be a stick, a mast, a cab, a track, a bucket, a pulley, a hoist, and/or a motor-generator set, etc. electric mining shovel system—a plurality of components comprising an electric mining shovel. An electric mining shovel system can comprise an electric mining shovel, electric mining shovel operator, dispatch entity, mine in which the electric mining shovel digs, and/or material haulage machine (e.g. a mine haul truck), etc. electrical—pertaining to electricity. electrical variable—a sensed reading relating to an electrical component. For example, an electrical power measurement, an electrical voltage measurement, an electrical torque measurement, an electrical motor speed measurement, an electrical rotor current measurement, and/or an electrical transformer temperature measurement, etc. environmental variable—a variable concerning a situation around a machine. For example, in the case of an electric mining shovel, an environmental variable can be a condition of material under excavation, weather condition, and/or condition of an electrical power supply line, etc. equipment scheduling information—data associated with a plan for machinery such as locating, operating, storing, and/or maintaining, etc. expected—anticipated. export—to send and/or transform data from a first format to a second format. failed component—a part no longer capable of functioning according to design. failure—a cessation of proper functioning or performance. format—an arrangement of data for storage or display. generate—produce. graphical—a pictorial and/or charted representation. heuristic rule—an empirical rule based upon experience, a simplification, and/or an educated guess that reduces and/or limits the search for solutions in domains that can be difficult and/or poorly understood. hoist—a system comprising motor adapted to at least vertically move a bucket of a mining shovel. identification—evidence of identity; something that identifies a person or thing. inactive—idle. initialization file—a file comprising information identifying a machine and the transmission of sensor data from the machine. information—data that has been organized to express concepts. It is generally possible to automate certain tasks involving the management, organization, transformation, and/or presentation of information. information device—any general purpose and/or special purpose computer, such as a personal computer, video game system (e.g., PlayStation, Nintendo Gameboy, X-Box, etc.), workstation, server, minicomputer, mainframe, supercomputer, computer terminal, laptop, wearable computer, and/or Personal Digital Assistant (PDA), mobile terminal, Bluetooth device, communicator, “smart” phone (such as a Handspring Treo-like device), messaging service (e.g., Blackberry) receiver, pager, facsimile, cellular telephone, a traditional telephone, telephonic device, a programmed microprocessor or microcontroller and/or peripheral integrated circuit elements, an ASIC or other integrated circuit, a hardware electronic logic circuit such as a discrete element circuit, and/or a programmable logic device such as a PLD, PLA, FPGA, or PAL, or the like, etc. In general any device on which resides a finite state machine capable of implementing at least a portion of a method, structure, and/or or graphical user interface described herein may be used as an information device. An information device can include well-known components such as one or more network interfaces, one or more processors, one or more memories containing instructions, and/or one or more input/output (I/O) devices, etc. Input/Output (I/O) device—the input/output (I/O) device of the information device can be any sensory-oriented input and/or output device, such as an audio, visual, haptic, olfactory, and/or taste-oriented device, including, for example, a monitor, display, projector, overhead display, keyboard, keypad, mouse, trackball, joystick, gamepad, wheel, touchpad, touch panel, pointing device, microphone, speaker, video camera, camera, scanner, printer, haptic device, vibrator, tactile simulator, and/or tactile pad, potentially including a port to which an I/O device can be attached or connected. load—an amount of mined earthen material associated with a bucket and/or truck, etc. load cycle—a time interval beginning when a mine shovel digs earthen material and ending when a bucket of the mining shovel is emptied into a haulage machine. log file—an organized record of information and/or events. machine performance variable—a property associated with an activity of a machine. For example, in the case of an electric mining shovel, a machine performance variable can be machine position, tons loaded per bucket, tons loaded per truck, tons loaded per time period, trucks loaded per time period, machine downtime, electrical downtime, and/or mechanical downtime, etc. Machine Search Language engine—machine readable instructions adapted to query information stored in an organized manner. For example, a machine search language engine can search information stored in a database. maintenance—an activity relating to restoring and/or preserving performance of a device and/or system. maintenance activity—an activity relating to restoring and/or preserving performance of a device and/or system. maintenance entity—a person and/or information device adapted restore and/or preserve performance associated with a device or system. management entity—a person and/or information device adapted to handle, supervise, control, direct, and/or govern activities associated with a machine. material—any substance that can be excavated and/or scooped. maximum acceptable value—a greatest amount in a predetermined range. measurement—a value of a variable, the value determined by manual and/or automatic observation. mechanical component—a device and/or system associated with a machine that is not primarily associated with using, switching, and/or transporting electricity. A mechanical component can be a bearing, cable, cable reel, gear, track pad, sprocket, chain, shaft, pump casing, gearbox, lubrication system, drum, brake, wear pad, bucket, bucket tooth, cable, and/or power transmission coupling, etc. mechanical performance—performance related to a mechanical component or system. For example, mechanical performance can relate to a bearing, gearbox, lubrication system, drum, brake, wear pad, bucket, bucket tooth, cable, power transmission coupling, and/or pump, etc. mechanical variable—a sensed reading relating to a mechanical component. For example, a bearing temperature measurement, an air pressure measurement, machine load reactions, and/or lubrication system pressure measurements, etc. memory device—any device capable of storing analog or digital information, for example, a non-volatile memory, volatile memory, Random Access Memory, RAM, Read Only Memory, ROM, flash memory, magnetic media, a hard disk, a floppy disk, a magnetic tape, an optical media, an optical disk, a compact disk, a CD, a digital versatile disk, a DVD, and/or a raid array, etc. The memory device can be coupled to a processor and can store instructions adapted to be executed by the processor according to an embodiment disclosed herein. metric—a measurement, deviation, and/or calculated value related to a measurement and/or deviation, etc. Microsoft Access format—information formatted according to a standard associated with the Microsoft Corp. of Redmond, Wash. Microsoft Excel format—information formatted according to a standard associated with the Microsoft Corp. of Redmond, Wash. mine—a site from which earthen materials can be extracted. mine dispatch entity—a person and/or information device adapted to monitor, schedule, and/or control activities and/or personnel associated with an earthen materials extraction operation. mine dispatcher—an entity performing scheduling and/or monitoring of equipment and/or personnel in an earthen materials extraction operation. mine dispatch system—a collection of mechanisms, devices, instructions, and/or personnel adapted to schedule and/or monitor equipment and/or personnel in an earthen materials extraction operation. minimum acceptable value—a smallest amount in a predetermined range. min/max pointer—a graphical rendering of a low and high operating range of a process variable associated with the electric mining shovel. motion gauge—a graphical rendering of a gauge associated with an electrical mining shovel. motion strip chart—a graphical rendering of a stream of process data displayed as a function of time. motion XY plot—a graphical rendering of a stream of process data displayed as a function of a non-time variable. non-binary—represented by more than two values. For example, a weight of 45 tons is non-binary; by contrast, a value, such as zero, representing a machine in an off state can be binary if an on state is solely represented by a different single value. non-digging activities—activities not involving excavating or scooping. For example, in the case of an electric mining shovel, non-digging can comprise bank cleanup, scraping, operator training, and/or repositioning an electrical cable, etc. non-load—not related to a load or quantity of material. non-positional—not related to a physical location. notify—to advise and/or remind. operational variable—a variable related to operating a machine. For example, an operation variable can be a technique used by an operator to accomplish a task with a first machine (e.g. a path used to lift a load in an electric mining shovel bucket), technique of an operator of a second machine used in conjunction with the first machine (e.g. how a mine haul truck spots relative to the electric mining shovel), practice of scheduling machines and/or personnel by a machine dispatch entity, number of second machines assigned in conjunction with the first machine, characteristics of second machines assigned in conjunction with the first machine (e.g. size, load capacity, dimensions, brand, and/or horsepower, etc.), production time period length, operator rest break length, scheduled production time for the machine, a cycle time, and/or a material weight, etc. operator—one observing and/or controlling a machine or device. pan—to move a rendering to follow an object or create a panoramic effect. panel—a surface containing switches and dials and meters for controlling a device. part—component. performance—an assessment. Performance can be measured by a characteristic related to an activity. position—location relative to a reference point. predetermined standard—a value and/or range established in advance. processor—a hardware, firmware, and/or software machine and/or virtual machine comprising a set of machine-readable instructions adaptable to perform a specific task. A processor acts upon information by manipulating, analyzing, modifying, converting, transmitting the information to another processor or an information device, and/or routing the information to an output device. production data—information indicative of a measure relating to an activity involving operation of a machine. For example, bucket load weight, truck load weight, last truck load weight, total weight during a defined production time period, operator reaction, and/or cycle timer associated with the electric mining shovel, etc. propelled motion—a linear and/or curvilinear movement of a machine from a first point to a second point. query—obtain information from a database responsive to a structured request. real-time—substantially contemporaneous to a current time. For example, a real-time transmission of information can be initiated and/or completed within about 120, 60, 30, 15, 10, 5, and/or 2, etc. seconds of receiving a request for the information. remote—in a distinctly different location. rendered—made perceptible to a human. For example data, commands, text, graphics, audio, video, animation, and/or hyperlinks, etc. can be rendered. Rendering can be via any visual and/or audio means, such as via a display, a monitor, electric paper, an ocular implant, a speaker, and/or a cochlear implant, etc. report—a presentation of information in a predetermined format. representative data—a plurality of measurement data associated with defined times. For example, representative data can be a plurality of readings from sensor taken over a time period. reset—a control adapted to clear and/or change a threshold. save—retain data in a memory device. schedule—plan for performing work. schematic model—a logical rendering representative of a device and/or system. search—a thorough examination or investigation. search control—one or more sets of machine readable instructions adapted to query a database in a predetermined manner responsive to a user selection. select—choose. sensor—a device adapted to measure a property. For example, a sensor can measure pressure, temperature, flow, mass, heat, light, sound, humidity, proximity, position, velocity, vibration, voltage, current, capacitance, resistance, inductance, and/or electromagnetic radiation, etc. server—an information device and/or software that provides some service for other connected information devices via a network. shovel motion control variable—a sensed reading relating to motion control in a mining shovel. For example, a hoist rope length, a stick extension, and/or a swing angle, etc. source—an origin of data. For example, a source can be a sensor, wireless transceiver, memory device, information device, and/or user, etc. statistical metric—a calculated value related to a plurality of data points. Examples include an average, mean, median, mode, minimum, maximum, integral, local minimum, weighted average, standard deviation, variance, control chart range, statistical analysis of variance parameter, statistical hypothesis testing value, and/or a deviation from a standard value, etc. status—information relating to a descriptive characteristic of a device and or system. For example, a status can be on, off, and/or in fault, etc. store—save information on a memory device. subset—a portion of a plurality. time period—an interval of time. transmit—send a signal. A signal can be sent, for example, via a wire or a wireless medium. transmission rate—a rate associated with a sampling and/or transfer of data, and not a modulation frequency. Units can be, for example, bits per second, symbols per second, and/or samples per second. user—a person interfacing with an information device. user interface—any device for rendering information to a user and/or requesting information from the user. A user interface includes at least one of textual, graphical, audio, video, animation, and/or haptic elements. user selected—stated, provided, and/or determined by a user. validate—to establish the soundness of, e.g. to determine whether a communications link is operational. value—an assigned or calculated numerical quantity. variable—a property capable of assuming any of an associated set of values. velocity—speed. visualize—to make visible. visually-renderable—adapted to be rendered on a visual means such as a display, monitor, paper, and/or electric paper, etc. wireless—any means to transmit a signal that does not require the use of a wire connecting a transmitter and a receiver, such as radio waves, electromagnetic signals at any frequency, lasers, microwaves, etc., but excluding purely visual signaling, such as semaphore, smoke signals, sign language, etc. wirelessly receiving user—a user that acquires, directly or indirectly, wirelessly transmitted information. wireless transmitter—a device adapted to transfer a signal from a source to a destination without the use of wires. zoom—magnify a rendering.
DETAILED DESCRIPTION
[0167] FIG. 1 is a block diagram of an exemplary embodiment of a machine data management system 1000 . Machine data management system 1000 can comprise a machine 1100 . In certain exemplary embodiments, machine 1100 can be a mining shovel such as an electric mining shovel, blast hole drill, truck, locomotive, automobile, front end loader, bucket wheel excavator, pump, fan, compressor, and/or industrial process machine, etc. Machine 1100 can be powered by one or more diesel engines, gasoline engines, and/or electric motors, etc.
[0168] Machine 1100 can comprise a plurality of sensors 1120 , 1130 , 1140 . Any of sensors 1120 , 1130 , 1140 can measure, for example: time, pressure, temperature, flow, mass, heat, flux, light, sound, humidity, proximity, position, velocity, acceleration, vibration, voltage, current, capacitance, resistance, inductance, and/or electromagnetic radiation, etc., and/or a change of any of those properties with respect to time, position, area, etc. Sensors 1120 , 1130 , 1140 can provide information at a data rate and/or frequency of, for example, between 0.1 and 500 readings per second, including all subranges and all values therebetween, such as for example, 100, 88, 61, 49, 23, 1, 0.5, and/or 0.1, etc. readings per second. Any of sensors 1120 , 1130 , 1140 can be communicatively coupled to an information device 1160 .
[0169] Information obtained from sensors 1120 , 1130 , 1140 related to machine 1100 can be analyzed while machine 1100 is operating. Information from 1120 , 1130 , 1140 can relate to performance of at least one of the measurable parts of the electrical system, performance of at least one of the measurable parts of the mechanical system, performance of one or more operators, and/or performance of one or more dispatch entities associated with machine 1100 , etc.
[0170] The dispatch entity can be associated with a dispatch system. The dispatch system can be an information system associated with the machine. The dispatch system can collect data from many diverse machines and formulate reports of production associated with machine 1100 , personnel and/or management entities associated with the production, a location receiving the production, and/or production movement times, etc. Certain exemplary embodiments can collect information related to machine 1100 through operator input codes.
[0171] Information device 1160 can comprise a user interface 1170 and/or a user program 1180 . User program 1180 can, for example, be adapted to obtain, store, and/or accumulate information related to machine 1100 . For example, user program 1180 can store, process, calculate, and/or analyze information provided by sensors 1120 , 1130 , 1140 as machine 1100 operates and/or functions, etc. User interface 1170 can be adapted to receive user input and/or render output to a user, such as information provided by and/or derived from sensors 1120 , 1130 , 1140 as machine 1100 operates and/or functions, etc.
[0172] Information device 1160 can be adapted to process information related to any of sensors 1120 , 1130 , 1140 . For example, information device 1160 can detect and/or anticipate a problem related to machine 1100 . Information device 1160 can be adapted to notify a user with information regarding machine 1100 .
[0173] Any of sensors 1120 , 1130 , 1140 , and/or information device 1160 can be communicatively coupled to a wireless transmitter and/or transceiver 1150 . Wireless transceiver 1150 can be adapted to communicate data related to machine 1100 to a second wireless receiver and/or transceiver 1200 . Data related to machine 1100 can comprise electrical measurements and/or variables such as voltages, currents, resistances, and/or inductances, etc.; mechanical measurements and/or variables such as torques, shaft speeds, and/or accelerations, etc.; temperature measurements and/or variables such as from a motor, bearing, and/or transformer, etc.; pressure measurements and/or variables such as air and/or lubrication pressures; production data and/or variables (e.g. weight and/or load related data) such as dipper load, truck load, last truck load, shift total weight; and/or time measurements; motion control measurements and/or variables such as, for certain movable machine components, power, torque, speed, and/or rotor currents; etc.
[0174] A network 1300 can communicatively couple wireless transceiver 1200 to devices such as an information device 1500 and/or a server 1400 . Server 1400 can be adapted to receive information transmitted from machine 1100 via wireless transceiver 1150 and wireless transceiver 1200 . Server 1400 can be communicatively coupled to a memory device 1600 . Memory device 1600 can be adapted to store information from machine 1100 . Memory device 1600 can store information, for example, in a format compatible with a database standard such as XML, Microsoft SQL, Microsoft Access, MySQL, Oracle, FileMaker, Sybase, and/or DB2, etc.
[0175] Server 1400 can comprise an input processor 1425 and a storage processor 1450 . Input processor 1425 can be adapted to receive representative data, such as data generated by sensors 1120 , 1130 , 1140 , from wireless transceiver 1200 . The representative data can be transmitted responsive to a transmission rate selected by a wirelessly receiving user. Storage processor 1450 can be adapted to store representative data generated from sensors 1120 , 1130 , 1140 on memory device 1600 .
[0176] Information device 1500 can be adapted to obtain and/or receive information from server 1400 related to machine 1100 . Information device 1500 can comprise a user interface 1560 and/or a client program 1540 . Client program 1540 can, for example, be adapted to obtain and/or accumulate information related to operating and/or maintaining machine 1100 . Client program 1540 can be adapted to notify a user via user interface 1560 with information indicative of a current or pending failure related to machine 1100 . Information device 1500 can communicate with machine 1100 via wireless transceiver 1200 and wireless transceiver 1150 . Information device 1500 can notify and/or render information for the user via user interface 1520 .
[0177] Information device 1500 can comprise an input processor 1525 and a report processor 1575 . In certain exemplary embodiments, input processor 1525 can be adapted to receive representative data, such as data generated by and/or derived from sensors 1120 , 1130 , 1140 . The representative data can be transmitted responsive to a data transmission rate selected by a wirelessly receiving user. Report processor 1575 can be adapted to render at least one report responsive to received and/or representative data, such as data obtained from, for example, memory device 1600 .
[0178] FIG. 2 is a flow diagram of an exemplary embodiment of a data management method 2000 for a machine. Data management method 2000 can be used for reporting, improving, optimizing, predicting, and/or analyzing operations related to activities such as mining, driving, and/or manufacturing, etc. At activity 2100 , data can be received at an information device associated with the machine. In certain exemplary embodiments, the information device can be local to the machine. The information device can be adapted to store, process, filter, correlate, transform, compress, analyze, report, render, and/or transfer the data to a first wireless transceiver, etc.
[0179] In certain exemplary embodiments, the information device can be remote from the machine. The information device can receive data transmitted via a first wireless transceiver associated with the machine and a second wireless transceiver remote from the machine. The information device can be adapted to receive the data indirectly via a memory device. The information device can be adapted to integrate information from a plurality of sources into a database. Integrating information can comprise associating data values from a plurality of sources to a common timeclock.
[0180] In certain exemplary embodiments the data can comprise an initialization file. The initialization file can be transmitted to and/or received by a server that can be remote from the machine. The initialization file can comprise identification information related to the machine. The initialization file can comprise, for example, a moniker associated with the machine, a type of the machine, an address of the machine, information related to the transmission rate of data originating at the machine, transmission scan interval, log directory, time of day to start a log file, and/or information identifying the order in which data is sent and/or identification information relating to sensors associated with the machine from which data originates.
[0181] In certain exemplary embodiments, data can be received from a machine dispatch entity that can comprise information related to the actions of a machine dispatcher, haulage machines associated with an excavation machine, equipment scheduling, personnel scheduling, maintenance schedules, historical production data, and/or production objectives, etc.
[0182] At activity 2200 , the data can be transmitted. The data can be transmitted via the first wireless transceiver to the second wireless transceiver. The second wireless transceiver can transmit the information via a wired and/or wireless connection to at least one wirelessly receiving information device to be stored, viewed, and/or analyzed by at least one wirelessly receiving user and/or information device. In certain exemplary embodiments, transmitted data can be routed and/or received by a remote server communicatively coupled to, for example, the second wireless transceiver via a network.
[0183] In certain exemplary embodiments, the data can comprise information relating to a status of the machine. The status of the machine can comprise, for example, properly operating, shut down, undergoing scheduled maintenance, operating but not producing a product, and/or relocating, etc. The status of the machine can be provided to and/or viewed by the user via a user interface.
[0184] At activity 2300 , a transmission rate can be received at an apparatus and/or system associated with the machine and adapted to adjust transmissions from the machine responsive to the transmission rate. The transmission rate can be received from a second information device remote from the machine and/or the wirelessly receiving user. The transmission rate can be related to a transmission rate between at least the first wireless transceiver and the second wireless transceiver, and/or a sampling rate associated with data supplied from at least one sensor to the first wireless transceiver. The user can specify a transmission rate via a rendered user interface on an information device. In certain exemplary embodiments, the transmission rate can be selected via the rendered user via, for example, a pull down menu, radio button, and/or data entry cell, etc.
[0185] At activity 2400 , a data communication can be validated. For example, the first wireless transceiver can query and/or test transmissions from the second wireless receiver in order to find, correct, and/or report errors in at least one data transmission. In certain exemplary embodiments, a user can be provided with a status related to the data communication via a user interface based rendering.
[0186] At activity 2500 , data can be stored pursuant to receipt by an information device. The information device can store the data in a memory device. The data can be stored in a plurality of formats such as SQL, MySQL, Microsoft Access, Oracle, FileMaker, Excel, SYLK, ASCII, Sybase, XML, and/or DB2, etc.
[0187] At activity 2600 , data can be compared to a standard. The standard can be a predetermined value, limit, data point, and/or pattern of data related to the machine. Comparing data to a standard can, for example, determine a past, present, or impending mechanical failure; electrical failure; operator error; operator performance; and/or supervisor performance, etc.
[0188] At activity 2650 , a failure can be detected. The failure can be associated with a mechanical and/or electrical component of the machine. For example, the mechanical failure can relate to a bearing, wear pad, engine, gear, and/or valve, etc. The electrical failure can relate to a connecting wire, motor, motor controller, starter, motor controller, transformer, capacitor, diode, resistor, and/or integrated circuit, etc.
[0189] At activity 2700 , a user can be alerted. The user can be local to the machine and/or operating the machine. In certain exemplary embodiments, the user can be the wirelessly receiving user, the dispatch entity, a management entity, and/or a maintenance entity. The user can be automatically notified to schedule and/or perform a maintenance activity associated with the machine.
[0190] At activity 2800 , data can be queried. The data related to the machine can be parsed and or extracted from a memory device. The data can be compared to a predetermined threshold and/or pattern. The data can be summarized and/or reported subsequent to the query. Querying the data can allow the wirelessly receiving user to manipulate and/or analyze the data related to the machine. In certain exemplary embodiments the data can be queried using a Machine Search Language engine.
[0191] Certain exemplary embodiments can monitor the machine while the machine is operating. Machine analysis functions can evaluate events associated with the machine. Machine analysis functions can determine causes of events and/or conditions that precede one or more events, such as a failure. Received data can be analyzed to detect average, below average, and/or above average performance associated with the machine. The information associated with the machine can be correlated with the dispatch system. In certain exemplary embodiments, applications can be customized towards individualized needs of operational units associated with the machine, such as a mine.
[0192] Certain exemplary embodiments can be adapted to remotely visualize operations associated with the machine from a perspective approximating that of an operator of the machine. Continuous monitoring and logging can take away “right timing” constraints on making direct observations of the machine. That is, performance can be logged and reviewed at a later time.
[0193] At activity 2850 , a report can be rendered. The report can comprise a summary of the data and/or exceptions noted during an analysis of the data. The report can comprise information related to, for example, actual torques, speeds, operator control positions, dispatch data, production, energy use associated with the machine, machine position, machine motion, and/or cycle times associated with the machine, etc. The report can comprise information related to the operation of the machine. For example, wherein the machine is a mining shovel, the report can comprise information related to the mining shovel digging, operating but not digging, propelling, idling, offline, total tons produced in a predetermined time period, total haulage machines loaded in the predetermined time period, average cycle time, average tons mined, and/or average haulage machine loads transferred, etc. The report can provide operating and/or maintenance entities with information related to the machine; recommend a course of action related to the operation and/or maintenance of the machine; historical and/or predictive information; trends in data, machine production data; and/or at least one deviation from an expected condition as calculated based upon the data; etc.
[0194] In certain exemplary embodiments, the data can be rendered and/or updated via a user interface in real-time with respect to the sensing of the physical properties underlying the data, and/or the generation, collection, and/or transmission of the data from the machine. The user interface can be automatically updated responsive to updates and/or changes to the data as received from the machine. In certain exemplary embodiments data can be rendered via the user interface from a user selected subset of sensors of a plurality of sensors associated with the machine. In certain exemplary embodiments data can be rendered via the user interface from a user selected subset of data point, such as, for example, every 8 th data point, every data point having a value outside a predetermined limit, every data point corresponding to a predetermined event, etc. The user can select a time period over which historical data can be rendered via the user interface. In this manner the user can analyze historical events in order to determine trends and/or assist in improving machine operations and/or maintenance.
[0195] In certain exemplary embodiments data from the machine can be rendered via the user interface which can comprise a 2-dimensional, 3-dimensional, and/or 4-dimensional (e.g., animated, or otherwise time-coupled) schematic model of the machine. The schematic model of the machine can assist the user in visualizing certain variables and/or their effects related to the machine. The schematic model of the machine can reflect a position of the machine relative to a fixed location, geographical position, and/or relative to another machine, etc. The schematic model can comprise proportionally accurate graphics and/or quantitative and/or qualitative indicators of conditions associated with one or more machine components. For a mining shovel, for example, the plurality of machine components can comprise hoist rope length, stick extension, and/or swing angles, etc. The rendering can comprise graphical indicators of joystick positions and the status displays that an operating entity can sense while running the machine. In this way, the rendering can be adapted to show a mechanical response of the machine under a given set of conditions and/or how the operating entity judges the mechanical response. The rendering can comprise an electrical response of the machine and/or how the operating entity judges the electrical response. In certain exemplary embodiments, data rendered from the machine can comprise GPS based positioning information related to the machine. The data can comprise information related to a survey. For example, in a mining operation, mine survey information can be integrated with positioning information related to the machine.
[0196] The rendering can comprise production information related to the machine. In the case wherein the machine is an electric mining shovel, production information can comprise a bucket load, haulage machine load, last haulage machine load, shift total, and/or cycle timer value, etc. The rendering can comprise electrical information such as, for example, readings from line gauges, power gauges, line strip charts, power strip charts, and/or temperature sensors related to an electrical component such as a transformer, etc. The rendering can comprise mechanical information such as, for example, readings from temperature sensors related to a mechanical component such as a bearing, air pressure sensors, lubrication system pressure sensors, and/or vibration sensors, etc.
[0197] In certain exemplary embodiments data can be rendered via a user interface in one or more of a plurality of display formats. For example, data can be rendered on a motion strip chart, motion XY plot, and/or motion gauge, etc. Data can be rendered on a chart comprising a minimum and/or maximum pointer associated with the data. The minimum and/or maximum pointer can provide a comparison of a value of a process variable with a predetermined value thereby potentially suggesting that some form of intervention be undertaken. Certain exemplary embodiments can comprise a feature adapted to allow the minimum and/or maximum to be reset and/or changed. For example, the minimum and/or maximum can be changed as a result of experience and/or a change in design and/or operation of the machine. The minimum and/or maximum can be changed by, for example, an operating entity, management entity, and/or engineering entity, etc.
[0198] The rendering can comprise elements of graphic user interface, such as menu selections, buttons, command-keys, etc., adapted to save, print, change cursors, and/or zoom, etc. Certain exemplary embodiments can be adapted to allow the user to select a subset of sensors and/or data associated with the machine to be rendered. Certain exemplary embodiments can be adapted to allow the user to select a time range over which the data is rendered. Certain exemplary embodiments can be adapted to provide the user with an ability to load and play log files via the rendering. Rendering commands can include step forward, forward, fast forward, stop, step back, play back, and/or fast back, etc. Additional features can be provided for log positioning. Certain exemplary embodiments can comprise a drop down box adapted to accept a user selection of time intervals and/or a start time.
[0199] At activity 2900 , data can be exported. Data can be exported from a memory device. Data can be exported in a plurality of formats. For example, data formatted as a SQL database can be exported in a Microsoft Access database format, an ASCII format, and/or a Microsoft Excel spreadsheet format, etc.
[0200] FIG. 3 is a flow diagram of an exemplary embodiment of a machine data management method 3000 . At activity 3100 , data can be received at a server and/or an information device. The data can comprise a plurality of values for a plurality of machine system variables associated with one or more machine system components. The plurality of machine system variables can comprise operational variables, environmental variables, variables related to maintenance, variables related to mechanical performance of the machine, and/or variables related to electrical performance of the machine, etc. In certain exemplary embodiments, the machine can be an electric mining shovel. The plurality of machine system variables can comprise at least one operational variable. In certain exemplary embodiments, the at least one operational variable can be related to digging earthen material. In certain exemplary embodiments, the at least one operational variable can comprise non-binary values.
[0201] At activity 3200 , variables from the machine data can be correlated. For example, values for two of the plurality of machine system variables can be mathematically analyzed in order to determine a correlation between those variables. Determining a correlation between variables can, for example, provide insights into improving machine operations and/or reducing machine downtime.
[0202] At activity 3300 , a metric can be determined. The metric can be a statistical metric related to least one of the machine system variables. The metric can be, for example, a mean, average, mode, maximum, minimum, standard deviation, variance, control chart range, statistical analysis of variance parameter, statistical hypothesis testing value, and/or a deviation from a standard value, etc. Determining the metric can provide information adapted to improve machine operation, improve performance of a machine operating entity, improve performance of a machine dispatching entity, improve machine maintenance, and/or reduce machine downtime, etc.
[0203] At activity 3400 , the server and/or information device can determine a trend related to at least one of the machine system variables. The trend can be relative to time and/or another machine system variable. Determining the trend can provide information adapted to improve machine design, improve machine operation, improve performance of a machine operating entity, improve performance of a machine dispatching entity, improve machine maintenance, and/or reduce machine downtime, etc.
[0204] At activity 3500 , values for one or more variables can be compared. In certain exemplary embodiments, values for a variable can be compared to a predetermined standard. For example, a bearing vibration reading can be compared to a predetermined standard vibration amplitude, pattern, phase, velocity, acceleration, etc., the predetermined standard representing a value indicative of an impending failure. Predicting an impending bearing failure can allow proactive, predictive, and/or preventive maintenance rather than reactive maintenance. As another example, a production achieved via the machine can be compared with a predetermined minimum threshold. If the production achieved is less than the predetermined minimum, a management entity can be notified in order to initiate corrective actions. If the production achieved is above the predetermined minimum by a predetermined amount and/or percentage, the management entity can be notified to provide a reward and/or investigate the causes of the production achieved.
[0205] As yet another example, an operating temperature for an electric motor controller can be compared to a predetermined maximum. If the operating temperature exceeds the predetermined maximum, a maintenance entity can be notified that a cooling system has failed and/or is non-functional. Repairing the cooling system promptly can help prevent a failure of the electric motor controller due to overheating. As still another example, an electric mining shovel idle time while operating can be compared to a predetermined maximum threshold. If the electric mining shovel idle time exceeds the predetermined maximum threshold, a mine dispatch entity can be notified that at least one additional haulage machine should be assigned to the electric mining shovel in order to improve mine production.
[0206] As still another example, a lubrication system pressure and/or use can be compared to predetermined settings. If the lubrication system is down or not performing properly, an operational and/or maintenance entity can be notified. Tracking and/or comparing lubrication system characteristics can be useful in predicting and/or preventing failures associated with inadequate lubrication.
[0207] As a further example, machine productivity can be compared to a predetermined standard. For example, in a mining operation for predetermined production period, tons mined can be compared to a historical statistical metric associated with the machine. The machine productivity comparison can provide a management entity with information that can be adapted to improve performance related to a machine operator, a dispatch entity, a maintenance entity, and/or an operator associated with a related machine.
[0208] At activity 3600 , variables associated with the machine can be analyzed. In certain exemplary embodiments, two correlated variables associated with the machine can be analyzed. In embodiments wherein the machine is an electric mining shovel, the two correlated variables can be non-load-related and/or non-positional variables related to the electric mining shovel.
[0209] Analyzing variables associated with the machine can comprise utilizing a pattern classification and/or recognition algorithm such as a decision tree, Bayesian network, neural network, Gaussian process, independent component analysis, self-organized map, and/or support vector machine, etc. The algorithm can facilitate performing tasks such as pattern recognition, data mining, classification, and/or process modeling, etc. The algorithm can be adapted to improve performance and/or change its behavior responsive to past and/or present results encountered by the algorithm. The algorithm can be adaptively trained by presenting it examples of input and a corresponding desired output. For example, the input might be a plurality of sensor readings associated with a machine component and an experienced output a failure of a machine component. The algorithm can be trained using synthetic data and/or providing data related to the component prior to previously occurring failures. The algorithm can be applied to almost any problem that can be regarded as pattern recognition in some form. In certain exemplary embodiments, the algorithm can be implemented in software, firmware, and/or hardware, etc.
[0210] Certain exemplary embodiments can comprise analyzing a vibration related to the machine based on values from at least one vibration sensor. The values can relate, for example, to a time domain, frequency domain, phase domain, and/or relative location domain, etc. The values can be presented to the pattern recognition algorithm to find patterns associated with impending failures. The values can be normalized, for example, with respect to a frequency and/or phase of rotation associated with the machine. The values can be used to obtain dynamic information usable in detecting and/or classifying failures.
[0211] Failures associated with the machine can be preceded by a condition such as, for example, a changing tolerance, imbalance, and/or bearing wear, etc. The condition can result in a characteristic vibration signature associated with an impending failure. In certain exemplary embodiments, the characteristic vibration signature can be discernable from other random and/or definable patterns within and/or potentially within the values.
[0212] Certain exemplary embodiments can utilize frequency normalization of the values. For example, frequency variables associated with power spectral densities can be scaled to predetermined frequencies. Scaling frequency variables can provide clearer representations of certain spectral patterns.
[0213] Vibration sensor readings can be sampled and processed at constant and/or variable time intervals. Certain exemplary embodiments can demodulate the vibration sensor readings. In certain exemplary embodiments, a frequency spectrum can be computed via a Fourier transform technique. The pattern recognition algorithm can be adapted to recognize patterns in the frequency spectrum to predict an impending machine component failure.
[0214] The pattern recognition algorithm can comprise a plurality of heuristic rules, which can comprise, for example, descriptive characteristics of vibration patterns associated with a failure of the component of the machine. The heuristic rules can comprise links identifying likely causes, diagnostic procedures, and/or effects related to the failure. For example, the heuristic rules can be adapted to adjust maintenance, machine, and/or personnel schedules responsive to detecting an impending failure.
[0215] Activity 3600 can comprise, for example, predicting machine performance, predicting a failure related to the machine, predicting a failure related to a machine component, predicting a failure related to a mechanical machine component, and/or predicting a failure related to an electrical machine component.
[0216] At activity 3700 , a report can be generated. The report can comprise, for example, a machine performance variable; information related to performance of a dispatch entity, such as a mine dispatch entity; information related to performance of a machine mechanical component; information related to performance of an machine electrical component; information related to activities involving the machine, such as digging activities in the case of an electric mining shovel; information related to non-digging activities involving the machine, such as operator training; and/or information related to propelled motion of the machine; etc.
[0217] At activity 3800 , a management entity associated with the machine can be notified of information related to the machine. The management entity can be notified of certain comparisons associated with activity 3500 and/or results associated with activity 3600 . Notifying the management entity can allow for corrective action to be taken to avoid lower than desired performance. Notifying the management entity can provide the management entity with information usable to improve performance related to the machine.
[0218] At activity 3900 , a maintenance entity associated with the machine can be notified. Notifying the maintenance entity can provide for prompt repair and/or prompt scheduling of a repair associated with the machine. Information obtained via activity 3600 can provide information usable in improving preventative maintenance related to the machine.
[0219] FIG. 4 is a block diagram of an exemplary embodiment of an information device 4000 , which in certain operative embodiments can comprise, for example, information device 1160 , server 1400 , and information device 1500 of FIG. 1 . Information device 4000 can comprise any of numerous well-known components, such as for example, one or more network interfaces 4100 , one or more processors 4200 , one or more memories 4300 containing instructions 4400 , one or more input/output (I/O) devices 4500 , and/or one or more user interfaces 4600 coupled to I/O device 4500 , etc.
[0220] In certain exemplary embodiments, via one or more user interfaces 4600 , such as a graphical user interface, a user can view a rendering of information related to a machine.
[0221] FIGS. 5 a , 5 b , and 5 c are an exemplary embodiment of a partial log file layout for data associated with a mining shovel. Data comprised in the log file can be saved for analytical purposes.
[0222] FIG. 6 is an exemplary user interface showing a graphical trend chart of electrical data for a crowd motor of a mining shovel. The crowd motor is adaptable to provide motion to a bucket of the mining shovel toward, to “crowd”, material holdable by the bucket.
[0223] FIG. 7 is an exemplary user interface showing a graphical rendering of gauges displaying electrical data of a crowd motor of a mining shovel. Data used in generating the graphical rendering can be saved for analytical purposes. The graphical rendering be rendered approximately in real-time.
[0224] FIG. 8 is an exemplary user interface showing a relationship between speed and torque of a crowd motor of a mining shovel.
[0225] FIG. 9 is an exemplary user interface showing a graphical rendering of gauges displaying temperatures related to a mining shovel crowd. Data used in generating the graphical rendering can be saved for analytical purposes. The graphical rendering be rendered approximately in real-time.
[0226] FIG. 10 is an exemplary user interface showing information related to driver operation of a mining shovel. The graphical rendering be rendered approximately in real-time.
[0227] FIG. 11 is an exemplary user interface showing a graphical trend chart of electrical data for a hoist motor of a mining shovel.
[0228] FIG. 12 is an exemplary user interface showing a graphical rendering of gauges displaying electrical data for a hoist motor of a mining shovel. Data used in generating the graphical rendering can be saved for analytical purposes. The graphical rendering be rendered approximately in real-time.
[0229] FIG. 13 is an exemplary user interface showing a relationship between speed and torque of a hoist motor of a mining shovel.
[0230] FIG. 14 is an exemplary user interface showing a graphical rendering of gauges displaying temperatures related to a mining shovel hoist. Data used in generating the graphical rendering can be saved for analytical purposes. Maximum and/or minimum thresholds can be set for purposes of generating alarms and/or flagging data. The graphical rendering be rendered approximately in real-time.
[0231] FIG. 15 is an exemplary user interface showing a graphical trend chart of electrical data related to a mining shovel.
[0232] FIG. 16 is an exemplary user interface showing information related to mining shovel operations.
[0233] FIG. 17 is an exemplary user interface showing position information related to a mining shovel.
[0234] FIG. 18 is an exemplary user interface showing a graphical rendering of gauges displaying pressures of mining shovel components. Data used in generating the graphical rendering can be saved for analytical purposes. The graphical rendering be rendered approximately in real-time.
[0235] FIG. 19 is an exemplary user interface showing a graphical rendering of gauges displaying temperatures of mining shovel components.
[0236] FIG. 20 is an exemplary user interface showing a graphical rendering of gauges displaying electrical data of hoist, crowd, and swing motors of a mining shovel.
[0237] FIG. 21 is an exemplary user interface showing a graphical trend chart of motion data related to a mining shovel.
[0238] FIG. 22 is an exemplary user interface showing a graphical trend chart of production data related to a mining shovel.
[0239] FIG. 23 is an exemplary user interface showing a graphical rendering of gauges displaying production data of a mining shovel.
[0240] FIG. 24 is an exemplary user interface providing operating statuses of mining shovel components.
[0241] FIG. 25 is an exemplary user interface showing a graphical trend chart of electrical data for a swing motor of a mining shovel.
[0242] FIG. 26 is an exemplary user interface showing a graphical rendering of gauges displaying electrical data for a swing motor of a mining shovel.
[0243] FIG. 27 is an exemplary user interface showing a relationship between speed and torque of a swing motor of a mining shovel.
[0244] FIG. 28 is an exemplary user interface showing a graphical rendering of gauges displaying temperatures related to a mining shovel swing.
[0245] Still other embodiments will become readily apparent to those skilled in this art from reading the above-recited detailed description and drawings of certain exemplary embodiments. It should be understood that numerous variations, modifications, and additional embodiments are possible, and accordingly, all such variations, modifications, and embodiments are to be regarded as being within the spirit and scope of the appended claims. For example, regardless of the content of any portion (e.g., title, field, background, summary, abstract, drawing figure, etc.) of this application, unless clearly specified to the contrary, there is no requirement for the inclusion in any claim of the application of any particular described or illustrated activity or element, any particular sequence of such activities, or any particular interrelationship of such elements. Moreover, any activity can be repeated, any activity can be performed by multiple entities, and/or any element can be duplicated. Further, any activity or element can be excluded, the sequence of activities can vary, and/or the interrelationship of elements can vary. Accordingly, the descriptions and drawings are to be regarded as illustrative in nature, and not as restrictive. Moreover, when any number or range is described herein, unless clearly stated otherwise, that number or range is approximate.
[0246] When any range is described herein, unless clearly stated otherwise, that range includes all values therein and all subranges therein. Any information in any material (e.g., a United States patent, United States patent application, book, article, etc.) that has been incorporated by reference herein, is only incorporated by reference to the extent that no conflict exists between such information and the other statements and drawings set forth herein. In the event of such conflict, including a conflict that would render a claim invalid, then any such conflicting information in such incorporated by reference material is specifically not incorporated by reference herein. | Certain exemplary embodiments can comprise obtaining and analyzing data from at least one discrete machine, automatically determining relationships related to the data, taking corrective action to improve machine operation and/or maintenance, automatically and heuristically predicting a failure associated with the machine and/or recommending preventative maintenance in advance of the failure, and/or automating and analyzing mining shovels, etc. | 4 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation in part of U.S. Ser. No. 08/216378 filed Mar. 23, 1994 which is a continuation in part of U.S. Ser. No. 08/125723 filed Sep. 24, 1993, now U.S. Pat. No. 5,346,613, the contents of which are both hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the fluidized catalytic cracking (FCC) conversion of heavy hydrocarbons into lighter hydrocarbons with a fluidized stream of catalyst particles and regeneration of the catalyst particles to remove coke which acts to deactivate the catalyst.
2. Description of the Prior Art
Catalytic cracking is accomplished by contacting hydrocarbons in a reaction zone with a catalyst composed of freely divided particulate material. The reaction in catalytic cracking, as opposed to hydrocracking, is carried out in the absence of added hydrogen or the consumption of hydrogen. As the cracking reaction proceeds, substantial amounts of coke are deposited on the catalyst. A high temperature regeneration within a regeneration zone operation burns coke from the catalyst. Coke-containing catalyst, referred to herein as spent catalyst, is continually removed from the reaction zone and replaced by essentially coke-free catalyst from the regeneration zone. Fluidization of the catalyst particles by various gaseous streams allows the transport of catalyst between the reaction zone and regeneration zone. Methods for cracking hydrocarbons in a fluidized stream of catalyst, transporting catalyst between reaction and regeneration zones, and combusting coke in the regenerator are well known by those skilled in the art of FCC processes. To this end, the art is replete with vessel configurations for contacting catalyst particles with feed and regeneration gas, respectively.
Despite the long existence of the FCC process, techniques are continually sought for improving product recovery both in terms of product quantity and composition, i.e. yield and selectivity. Two facets of the FCC process that have received attention are recovery of adsorbed products from the spent FCC catalyst and initial contacting of the FCC feed with the regenerated catalyst. Improvement in the recovery of hydrocarbons from spent catalyst and better initial feed and catalyst contacting improves the yield and selectivity to selectivity to more valuable products.
The processing of increasingly heavier feeds and the tendency of such feeds to elevate coke production and yield undesirable products has led to new methods of contacting FCC feeds with catalyst. Of particular interest recently have been methods of contacting FCC catalyst for very short contact periods. U.S. Pat. No. 4,985,136 discloses an ultrashort contact time fluidized catalytic cracking process, the contents of which are hereby incorporated by reference that contacts an FCC feed with a falling curtain of catalyst for a contact time of less than 1 second followed by a quick separation. U.S. Pat. No. 5,296,131 the contents of which are hereby incorporated by reference discloses a similar ultrashort contact time process that uses an alternate falling catalyst curtain and separation arrangement. The ultrashort contact time system improves selectivity to gasoline while decreasing coke and dry gas production by using high activity catalyst that contact the feed for a relatively short period of time. The inventions are specifically directed to zeolite catalysts having high activity. The short contact time arrangements permit the use of much higher zeolite content catalysts that increase the usual 25-30% zeolite contents of the FCC catalyst to amounts as high as 40-60% zeolite in the cracking catalyst. These references teach that shorter hydrocarbon and catalyst contact time is compensated for by higher catalyst activity.
In traditional long contact time FCC systems, it has been known to recycle catalyst from the end of a conversion zone that contains coke deposits, i.e., spent catalyst, back to the bottom of a reactor zone. Examples of long contact time risers that use this type of arrangement are shown in U.S. Pat. No. 3,679,576 where spent and regenerated catalyst pass together momentarily through a short section a relatively small diameter conduit before contacting the FCC feed. The contacting of spent catalyst, regenerated catalyst, and feed has been shown to occur simultaneously in U.S. Pat. No. 3,888,762 where all components come together simultaneously in a riser conduit. These types of arrangements have not been successfully practiced in commercial units.
Thus, in FCC operation generally and particularly in the short contact time operation, maximization of feedstock conversion is ordinarily thought to require essentially complete removal of coke from the catalyst. This essentially-complete removal of coke from catalyst is often referred to as complete regeneration. Complete regeneration produces a catalyst having less than 0.1 and preferably less than 0.05 weight percent coke. In order to obtain complete regeneration, oxygen in excess of the stoichiometric amount necessary for the combustion of coke to carbon oxides is charged to the regenerator.
While the prior art has recognized that the potential benefits of short contact times in high activity catalyst in FCC processing arrangements, little attention has been paid to the catalysts circulation aspects of the process. Ultrashort contact times will reduce the amount of catalytic coke deposited on the catalyst. Operating an ultrashort contact time FCC process with complete regeneration will increase the total mass of solids circulated for the combustion of a given amount of coke. This effect will produce lower regenerator temperatures. Increasing the total amount of solid circulation through the reactor and regenerator for the combustion of a fixed amount of coke will adversely affect the kinetics within the regeneration zone. Circulating large amounts of catalyst with low coke concentrations unnecessarily increases the amount of mass circulated throughout the unit.
BRIEF SUMMARY OF THE INVENTION
Circulation problems of short contact time FCC processes are overcome by mixing of spent catalyst with regenerated catalyst upstream of the ultrashort contact time contacting of the feed with the catalyst blend. Recycling a portion of the spent catalyst that already contains coke increases the total catalyst circulation to the ultrashort contact time contacting section without increasing circulation through the regeneration zone. Multiple cycles of contacting of the catalyst with the feed before entering the regeneration zone increases the average coke content of the FCC catalyst that is sent to the regeneration zone. Since the spent catalyst has been discovered to retain a substantial amount of its cracking activity in the short contact time application, the catalyst retains a large amount of its activity in the total so that a much greater amount of catalyst is available for contacting feed. The recycle of spent catalyst also increases the total amount of catalyst circulation through the reaction zone and promotes better heating and feed contacting within the ultrashort contact time. On the regenerator side of the process, the higher coke content of the circulating catalyst promotes a high temperature regeneration operation, thereby improving combustion kinetics, so that complete regeneration and CO combustion of the coke entering the regeneration zone is obtained.
Combining both regenerated and spent catalyst increases the solids to feed ratio in the reaction zone. A greater solids ratio improves catalyst and feed contacting. Since the spent catalyst still has activity, the catalyst to oil ratio is increased. Moreover, the larger quantity of catalyst more evenly and quickly distributes heat to the feed and aids in the necessary quick transfer of heat for ultra short contact time processing. In addition, the larger amount of catalyst transfers heat to the catalyst at a reduced temperature differential between the catalyst and the feed. Together both of these effects lead to more uniform feed and catalyst contacting and a resulting decrease in dry gas production.
Spent catalyst recycled to the reaction zone in accordance with this invention preferably undergoes stripping before recontacting the feed. This invention does not require complete stripping of spent catalyst before recycle of the spent catalyst to the ultrashort contact time reaction zone. It is important to strip the spent catalyst to remove hydrocarbons from the void spaces of the catalyst as quickly as possible. This quick removal prevents overcracking in the stripper and preserves hydrocarbons in the gasoline boiling range. Thus, the desired degree of stripping for catalyst returning to the reaction zone should provide displacement of hydrocarbons from the void spaces between and within catalyst particles. The remaining spent catalyst particles may undergo a more severe stripping operation to remove or react away hydrocarbon material adsorbed on the catalyst particles.
In another preferred form of practicing the invention, the method of ultrashort contact time contacting will provide a degree of separation between the more highly and less highly coke contaminated catalyst particles. The less highly coke contaminated particles will preferentially return to the ultrashort contact time contacting zone with a higher percentage of the heavily coked catalyst particles passing to the regeneration zone.
Accordingly, in one embodiment this invention is a process for the fluidized catalytic cracking of an FCC feed. The process forms a falling curtain of FCC catalyst in a reaction zone by discharging a mixture of FCC catalyst downwardly from a discharge point. The falling curtain of catalyst contacts the FCC feed in the reaction zone by discharging the feed transversely into the falling curtain of FCC catalyst to crack hydrocarbons in the feed and produce lighter hydrocarbon products. Contacting of the feed with the falling curtain of catalyst forms coke on the FCC catalyst. The hydrocarbon products are separated from the coked FCC catalyst after a hydrocarbon and catalyst contact time of less than 1 second, and a hydrocarbon product stream is recovered. A portion of the coked FCC catalyst passes to a regeneration zone that combusts coke from the coked FCC catalyst to produce a regenerated FCC catalyst having a carbon content of less than 0.1 wt %. Regenerated catalyst and coke containing catalyst are combined to produce the mixture of FCC catalyst.
Additional objects, embodiments, and details of this invention will become apparent from the following detailed description.
BRIEF DESCRIPTION OF THE DRAWING
The Figure is a schematic illustration of a short contact time FCC reactor arrangement that incorporates the spent catalyst recycle of this invention.
DETAILED DESCRIPTION OF THE INVENTION
This invention is more fully explained in the context of an FCC process. The drawing of this invention shows a typical FCC process arrangement. The description of this invention in the context of the specific process arrangement shown is not meant to limit it to the details disclosed therein. The FCC arrangement shown in FIG. 1 consists of a reactor 10, a regenerator zone 12, a blending vessel 14 which can also serve as a secondary stripper, a primary stripping vessel 16 and a displacement stripping vessel 18. The arrangement circulates catalyst and contacts feed in the manner hereinafter described.
The catalyst that enters the riser can include any of the well-known catalysts that are used in the art of fluidized catalytic cracking. These compositions include amorphous-clay type catalysts which have, for the most part, been replaced by high activity, crystalline alumina silica or zeolite containing catalysts. Zeolite catalysts are preferred over amorphous-type catalysts because of their higher intrinsic activity and their higher resistance to the deactivating effects of high temperature exposure to steam and exposure to the metals contained in most feedstocks. Zeolites are the most commonly used crystalline alumina silicates and are usually dispersed in a porous inorganic carrier material such as silica, alumina, or zirconium. These catalyst compositions may have a zeolite content of 30% or more. Zeolite catalysts used in the process of this invention will preferably have a zeolite content of from 25-80 wt % of the catalyst. The zeolites may also be stabilized with rare earth elements and contain from 0.1 to 10 wt % of rare earths.
FCC feedstocks, suitable for processing by the method of this invention, include conventional FCC feeds and higher boiling or residual feeds. The most common of the conventional feeds is a vacuum gas oil which is typically a hydrocarbon material having a boiling range of from 650°-1025° F. and is prepared by vacuum fractionation of atmospheric residue. These fractions are generally low in coke precursors and the heavy metals which can deactivate the catalyst. Heavy or residual feeds, i.e., boiling above 930° F. and which have a high metals content, are finding increased usage in FCC units. These residual feeds are characterized by a higher degree of coke deposition on the catalyst when cracked. Both the metals and coke serve to deactivate the catalyst by blocking active sites on the catalysts. Coke can be removed to a desired degree by regeneration and its deactivating effects overcome. Metals, however, accumulate on the catalyst and poison the catalyst. In addition, the metals promote undesirable cracking thereby interfering with the reaction process. Thus, the presence of metals usually influences the regenerator operation, catalyst selectivity, catalyst activity, and the fresh catalyst makeup required to maintain constant activity. The contaminant metals include nickel, iron, and vanadium. In general, these metals affect selectivity in the direction of less gasoline, and more coke and dry gas. Due to these deleterious effects, the use of metal management procedures within or before the reaction zone are anticipated in processing heavy feeds by this invention. Metals passivation can also be achieved to some extent by the use of an appropriate lift gas in the upstream portion of the riser.
Looking then at the reactor side of FIG. 1, FCC feed from a conduit 19 is mixed with an additional fluidizing medium from a line 20, in this case steam, and charged to an injection nozzle 22. Injection nozzle 22 atomizes the feed into a stream of fine liquid droplets 24 that contacts a falling curtain of catalyst 26. Contact of the feed with the catalyst causes a rapid vaporization and a high velocity discharge of catalyst in the direction of a cyclone inlet 28.
Contact between the feed and catalyst cracks the heavier hydrocarbons into lighter hydrocarbons and produces coking of the most active catalyst sites on the catalyst. As the catalyst moves toward cyclone inlet 28, a portion of the catalyst particles fall from the stream of mixed catalyst and feed downwardly through the reactor vessel into the top of primary stripping zone 16. The transverse contacting of the feed with the vertically falling catalyst curtain creates a beneficial trajectory of the catalyst and feed mixture towards inlet 28. Projecting the mixture of catalyst and cracked vapors toward the inlet 28 has the advantage of separating the catalyst particles. Advantageously, the heavier particles, those containing the most coke, preferentially fall into stripper 16 while the lighter less coked particles enter cyclone inlet 28 and are separated in cyclone 30. However, it is not necessary to the practice of this invention that the feed direct the catalyst in any particular direction.
The feed transversely contacts the curtain of falling catalyst to obtain a quick contacting between the feed and the catalyst particles. For the purposes of this description the expression transversely contacting means the feed does not flow parallel to the direction of the falling curtain. The feed injector 22 will produce a spray pattern that is compatible with the geometry of the falling curtain. Where the discharge point forms an annular falling curtain of catalyst, the feed injector will produce a radial pattern of flow that passes outwardly to contact the feed. Where the falling curtain has a linear shape as depicted in the figure, the feed injector will produce a fiat horizontal pattern of atomized charge. In any arrangement, hydrocarbon feed and catalyst contact, the mixture moves rapidly towards a separation device such that the hydrocarbons are separated from the catalyst after a contact time of less than 1 second, and preferably, the feed and catalyst mixture enters a separation device after a contact time of from 0.5 to 0.01 seconds. After the initial contacting, feed may be directed upwardly or downwardly, but it is preferentially directed toward the inlet 28. Accordingly, in a typical arrangement, the feed is discharged in a substantially horizontal direction to flow perpendicularly into contact with an essentially vertical curtain of catalyst. When contacting the falling curtain of catalyst, the feed will typically have a velocity of greater than 10 ft/sec and a temperature in the range of from 300° to 600° F.
Cyclone 30 provides an inertial separation device that rapidly removes the product vapors from the FCC catalyst. Product vapors are recovered from the cyclone via a line 32 for further separation in a main column separation section. Catalyst separated by cyclone 30 flows down to the bottom of the cyclone where a line 32 removes the catalyst particles. From line 32, the catalyst may be directed into primary stripping zone 16 or displacement stripping zone 18. Typically only one of lines 34 or 60 will be provided such that catalyst flows only into primary stripping zone 16 or displacement stripping zone 18. Suitable flow control means (not shown) may also be positioned in conduits 34 or 60 to selectively direct the flow of catalyst from line 32 into one or the other of stripping zone 16 or displacement stripping zone 18.
Line 34 carries catalyst from the cyclone into primary stripping zone 16 where the catalyst is combined with heavier catalyst particles that fall directly into the top of a catalyst bed 36. Stripping fluid, typically steam, enters primary stripping zone 16 via a line 38 and a distributor 40. Primary stripping zone 16 may contain baffles or other internal trays or arrangements to increase contacting between the stripping fluid and the catalyst. As a stripping fluid flows countercurrently to the bed, the stripping fluid primarily displaces hydrocarbons in the upper portion of bed 36 and more fully strips the catalyst by desorbing adsorbed hydrocarbons from the core volume of the catalyst in the lower portions of bed 36. A line 42 withdraws the most fully stripped catalyst from the bottom of primary stripping zone 16 at a rate controlled by control valve 44. Spent catalyst leaving the stripping zone will typically have an average coke concentration of from 0.5 to 1.0 wt %.
Line 42 transfers spent catalyst to the regeneration zone 12 where a combustion gas carried by a line 46 contacts the catalyst under coke combustion conditions within regeneration zone 12 to remove coke from the catalyst particles. Combustion of the coke generates flue gases that contain the by-products of coke combustion and are removed from the regeneration zone via a line 48 and fully regenerated catalyst particles that have a coke concentration of less than 0.2 wt % and preferably less than 0.1 wt %. Regeneration zone 12 may be any type of known FCC regenerator or arrangement. Such regeneration arrangements include single stage regeneration zones that maintain a bubbling bed for the combustion of coke, multiple stage regeneration zones that operate with multiple dense beds or a combination of dilute phase and dense bed combustion or a dilute phase riser type regeneration zones. Depending on the type of regeneration zone, appropriate means may be provided for pneumatically lifting catalyst into the regeneration zone or transferring catalyst back to the reaction zone.
A line 50 transports catalyst from the regeneration zone into the blending vessel 14. The blending vessel also receives a portion of the spent catalyst from the reaction zone. In the simplest form of the invention, a line 52 withdraws spent catalyst from an upper section of primary stripping zone 16 at a rate set by control valve 54. A lift medium such as steam pneumatically conveys the spent catalyst upwardly from a line 58 into blending vessel 14. Line 52 withdraws catalyst that has primarily undergone stripping for displacement of hydrocarbons from the void spaces between the catalyst particles. Since the spent catalyst is recontacting the feed, there is no need for a thorough stripping of the catalyst before recycling it through the blending vessel and back to the reaction zone. Aside from blending catalyst, an added benefit of this invention is the use of the blending vessel as a hot stripping zone and a metals passivation zone. When present the blending vessel may hold catalyst for a relatively long residence time. The blending vessel can also isolate passivation gas streams from the reactor and regenerator sides of the process. Therefore, the blending vessel can simultaneously serve as a passivation zone. The blending vessel may also be useful for the removal of sulfur or inert material from the catalyst.
Sufficient coke containing catalyst will be recycled such that the mixture of catalyst in the reaction zone contains at least 20 wt % coked catalyst and more typically 50 wt % coked catalyst. The coked catalyst recycled by line 52 to blending vessel 14 comprises a random mixture of particles having varying degrees of coke ranging from particles that have made several cycles through the reaction zone and thus contain a heavy coke concentration to particles that have only passed once through the reaction zone since regeneration. It is, of course, more desirable to recycle those particles that have had a shorter residence time on the reactor side of the process and regenerate those particles that have had the most cycles through the reaction zone and thus the heaviest loading of coke. Since the particles with the lightest loading of coke tend to be lower density, they are preferentially carried into cyclone 30. The heavier catalyst particles, as previously mentioned, have a tendency to drop out first and land directly in bed 36. Therefore, the process can also be operated with displacement stripping zone 18 that withdraws the spent and preferentially less coked catalyst particles from the cyclone via a line 60 that transfers the catalyst particles to displacement stripper 18. A stripping gas enters the bottom of displacement stripper 18 via a line 62 and performs a partial stripping of the catalyst which is, again, to primarily displace hydrocarbons from void spaces between the catalyst particles and maximize the recovery of wider hydrocarbon products. Spent gas and hydrocarbon products are taken overhead from displacement stripper 18 via a line 64 and either transferred directly back to the reaction zone via a line 66 for recovery in cyclone 30 or removed separately via line 68 for independent recovery in a downstream separation section.
A line 70 removes the stripped catalyst at a rate regulated by a valve 72 for lifting to the blending vessel 14 in a line 74 with the assistance of an appropriate lift gas from a line 76. Blending vessel 14 mixes the catalyst. Blending vessel 14 receives the hot catalyst from line 50 and spend catalyst from either or both of lines 58 and 74. Blending vessel 14 provides a variety of functions. The blending vessel ensures a thorough mixing of the spent and regenerated catalyst so that a blend of catalyst is supplied to the reaction zone. The regenerated catalyst that enters the blending vessel has a temperature in a range of from 1200°-1400° F. and the coked catalyst will usually have a temperature of from 900°-1100° F. Blended catalyst, as it leaves the blending vessel will usually have a temperature in a range of from 1000°-1250° F. Blending the spent and regenerated catalyst in the manner of this invention typically increases the relative amount of catalyst that contacts the feed. The amount of blended catalyst that contacts the feed will vary depending on the temperature of the blended catalyst and the ratio of spent to regenerated catalyst comprising the catalyst blend. Generally, the ratio of blended catalyst to feed will be in ratio of from 5 to 25. The term "blended catalyst" refers to the total amount of solids that contact the feed and include both the regenerated catalyst from the regenerator and the spent catalyst from the reactor side of the process. Preferably, the blended catalyst to feed will be in a ratio of from 10 to 20 and more preferably in ratio of from 10 to 15. This higher ratio of catalyst to feed promotes more rapid vaporization of the feed and increases the catalyst surface area in contact with the feed to make vaporization more uniform. Both of theses effects promote a more uniform distribution of feed through the riser. The greater quantity of catalyst reduces the added heat per pound of catalyst for raising the temperature of the entering feed so that a high feed temperature is achieved with less temperature differential between the feed and the catalyst. Reduction of the temperature differential between catalyst and feed minimizes the occurrence of undesirable thermal cracking reactions and replaces violent mixing with the more complete contacting offered by the elevated volume of catalyst.
In addition to the blending vessel also providing a residence time for the spent and regenerated catalyst to reach thermal equilibrium, it can also provide for a beneficial interaction between the freshly regenerated catalyst and the spent catalyst. While not wishing to be bound to any theory, this residence time between the spent and regenerated catalyst may offer a tempering of the regenerated catalyst through contact with the volatile coke material present on the spent catalyst.
For purposes of blending and mixing, an additional fluidizing gas may enter blending vessel 14 via a line 78. Blending vessel 14 also provides a degassing function for venting fluidizing gases that convey the catalyst into the vessel. Fluidization gas, entering vessel 14 from line 78 promotes mixing of catalyst within the vessel. Fluidizing gas entering the blending zone will have normally establish a superficial velocity of between 1 to 3. The blending vessel will ordinarily maintain a dense catalyst bed. Conditions within the blending zone typically include a density in a range of from 30 to 40 lb/ft 3 . Turbulent mixing within the dense catalyst bed fully blends the regenerated and spent catalyst. In this manner, mixing vessel 14 operates at least as a blending zone to supply the blended catalyst streams to the reactor and regenerator.
The blending zone may also provide an added stage of stripping. Stripping provides a particularly beneficial use of the blending zone. The blending of regenerated catalyst typically elevates the temperature of the blended catalyst so that a stripper blending zone provides hot stripping. Additionally, entrained inert gases from the regeneration step can be stripped from the catalyst in the blending vessel. Thus, the fluidizing gas entering through line 72 may comprise air, steam, additional feedstreams, etc.
A vent line 80 passes fluidizing gas out of the top of mixing vessel 14. Depending on its composition, the fluidizing gas may be passed back into the reactor for recovery of additional product vapors, processed separately to recover a secondary product stream or returned to the regeneration zone and combined with the flue gas stream exiting the regenerator.
A standpipe 82 at the bottom of blending vessel 14 supplies the blended catalyst mixture to a slide valve 84 that regulates the addition of the catalyst to the reaction zone. Catalyst from the slide valve enters a discharge chamber 86 that supplies catalyst to a discharge point 88. Discharge point 88 supplies a falling curtain of catalyst 26 that contacts the feed stream 24. The amount of catalyst discharged through discharge point 88 is a function of the size of the discharge point and the pressure head at discharge point 86. The pressure at discharge point 88 may be controlled in a variety of ways. Static pressure head may be provided by varying the height of a standpipe section 90 and controlling the level in that section through the regulation of catalyst passing through valve 84. A pressurization fluid may also be injected into discharge chamber 86 via a line 92. The pressurization fluid may provide a fluidizing function to maintain flow through discharge point 88 or may be used to increase the pressure in 88 and adjust the velocity of the curtain of catalyst passing through the discharge point. The falling curtain of catalyst will usually have a velocity of at least 10 ft/sec. The velocity through the discharge point may be increased in order to carry the mixture of hydrocarbon and catalyst farther down into the reactor vessel thereby lengthening the flow path and the residence time of the hydrocarbons within the reaction zone. Imparting greater momentum to the catalyst particles may also increase the separation between heavily and lightly coked catalyst particles such that the heavier coked catalysts are, again, more preferentially retained in the reaction zone and collected in directly in bed 36. | A short contact time FCC process raises the coke level of the spent catalyst to improve regeneration zone kinetics and to decrease the total solids circulation through the unit by passing spent catalyst from the reaction zone back to a blending vessel. The blending vessel supplies a mixture of spent and fully regenerated catalyst to the reaction zone. The invention may also preferentially recover lightly coked catalyst by segregating catalyst from a separation device for recycle to the reaction zone. | 2 |
BACKGROUND OF THE INVENTION
Field of the Invention
The invention relates in general to a game apparatus for use by two or more individuals who alternate in active participation. in particular, the invention relates to a game for use by at least two players where dice are thrown to fill certain spaces upon a play board.
In known prior art games where a pair of dice are utilized by the participants in an alternate play mode and, where markers and numbers are placed upon a play board in certain spaces comprising rows, columns, and diagonals of a checkerboard-like game board, no showing has been found that demonstrates a relationship between the board numbers with the numbers on the side faces of the dice. Furthermore, there are no known games in the marketplace or prior art where a winner's score is determined by a summation of the above mentioned board numbers with the first player to fill rows, columns, or diagonals with markers after a series of thrown dice has been executed.
SUMMARY OF THE INVENTION
The invention relates to a game apparatus for recreational activity that utilizes an appropriately divided checkerboard-like game board in conjunction with a pair of dice and markers. The purpose of the apparatus is for any one of a plurality of players to Complete a game by filling a predetermined number of row, column, and diagonal spaces with markers as the dice are alternately thrown by any of the participants.
The up faces of the thrown dice locate the markers on the row, column, and diagonal spaces on the play board and the summation of the numbers in the locations comprising the completed spaces determine the total score achieved. Several games may be played to produce a predetermined grand score total.
The basic structure of the game design permits numerous optional variations such that interest may be maintained after playing several rounds of the same game. One variation of the game apparatus of this invention requires that the rows and columns comprising the outside perimeter of the play board be completed with markers for a participant to win the game. In another variation, the game may be played such that only diagonals may be completed with markers. In these game variations, the score is determined upon a game completion by summing the preassigned numbers assigned to each space upon which a marker is located.
It is therefore an object of the invention to provide a new and improved game apparatus for two or more persons.
It is a further object of the invention to furnish a game apparatus which is adapted to be played in different formats using dice, markers, divided checkerboard-like play card where values are assigned that relate to the dice faces.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of the play board of the invention which is divided into row, column, and diagonal locations and a front elevational view of a pair of dice and markers as used with the play of the game to complete the various locations.
FIG. 2 is another plan view of the game board of the invention wherein a variation of the game of FIG. 1 is depicted.
FIG. 3 is another plan of the game board of the invention wherein still another variation of the game of FIG. 1 is illustrated.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings and in particular to FIG. 1 there is depicted a play card or board 10 which is divided into rows 22 to 27 and columns 15 to 20; and, each area of the rows and columns is designated, for example, as space 50. The divided game board 10 includes six basic rows and columns which are identified by an appropriate single digit in row 30 and column 40. The row and column identifiers aid the player in locating particular spaces on the board 10 as will become apparent upon further discussion hereinbelow. The game apparatus of the invention further includes a pair of dice 12 and a plurality of markers 14. The dice are thrown alternately by each player and markers 14 are positioned on the appropriate spaces 50 of the play board 10.
It is noted that each space 50 of the play board 10 includes a numeric in the form of an indicia that is consecutively located across row 22, for example. The numbered indicia in the upper left space corresponding to the intersection of row 1, column 1 is thirty. This number is derived by adding all of the digits of the pair of dice when the up faces are both one which correspond to row 1, column 1. The sum of the dice faces under this circumstance is the number thirty as indicated. As may be readily seen, each adjacent consecutive space beginning with space 50 increases by one numerical count until the indicia thirty-five is reached. The number thirty-two by way of further example is derived by positioning the up faces of a pair of dice 12 with the one and three digits facing upwardly and then adding all of the digits upon the remaining visible faces. The number thirty-two is therefore located in column three, row one.
In column 21 and row 28, there are located a plurality of numbers that represent the summation of a particular row and column. The column 21 and opposite row 22, for example, the indicia 195 is indicated which represents the summation of all of the numbers in the above-mentioned row. Similarly, in row 28, the number indicia 207 is located under column three. As above stated, this indicia represents the summation of all of the numbers in column three. It should also be noted that at the top of and bottom of column 21 the number 210 with a slanted arrow is depicted. The indicia 210 represents the numerical summation of either diagonal each of which includes six spaces 50.
The instant game may be played by a plurality of players where the minimum number is two. Each player is required to use at least one play card 10 for which a plurality of markers 14 is furnished; in addition, a one pair of dice 12 is supplied which may be utilized by all of the players.
The strategy of the game employing the game apparatus 10, 12, 14 requires that any player complete any row, column, or diagonal with the placement of markers that totals three; or in other words, any three completed columns or rows would satisfy this requirement as well as any combination of three where columns, rows, and diagonals are mixed. As an example, the first player to satisfy the completion of two diagonals and one row or, one diagonal, one row and one column would be declared a winner. The score that the winner achieved would be the summation of the total scores for the particular rows, columns, or diagonals that were filled with markers. The game disclosed herein may be structured so that the winner would be determined by achieving a grand total score of, for example, one-thousand. In that event, a series of plays would be required where the winning score of each game would be cumulative. In this arrangement, the loser would be allowed to accumulate a score for any completed columns, rows, or diagonals.
The markers 14 are positioned by the particular players on the various spaces 50 by the numbers produced by a throw of the dice 12. As an illustration, if a one and three were thrown by a particular player in the manner shown in FIG. 1, markers 13, 14 would be respectively positioned at the intersections of column one and row three as well as column three and row one. However, if identical numbers such as one, one and three, three were thrown by a player, only one space 50, namely, the intersection of row one and column one and the intersection of row three, column three would receive respective markers (dotted) 31, 39. In the event that doubles are thrown by the player, another turn is allowed.
Another embodiment of the invention is illustrated in FIG. 2 where the perimeter columns and rows only are completed with the various markers 12. In all other respects, the game 10 is played in the same manner as above described except that the score total achieved by a player only relate to the outside columns and rows. In this form of the game play, the loser may receive the score total of the rows and columns that have been completed.
Another embodiment of the invention is illustrated in FIG. 3 where the game is played in a form called doubles and sevens. By doubles is meant both up faces on the thrown dice 12 must have the same digit such, for example, as one, one or four, four. The diagonal beginning with the intersection one, one and ending with six, six can only be formed with markers 14 by throwing doubles. The diagonal beginning with the intersection one, six and ending with six, one can only be developed by throwing sevens. Sevens are defined as any throw of the dice where the up faces represent the following combinations: four, three; five, two; six, one.
This invention has been described by reference to precise embodiments, but it will be appreciated by those skilled in the art that this invention is subject to various modifications and to the extent that those modifications would be obvious to one of ordinary skill they are considered as being within the scope of the appended claims. | A game apparatus for alternative participation by a plurality of players using a pair of dice, markers, and a game card formed into intersecting columns, rows, and diagonal locations. A game object requires that any row, column, or diagonal locations be appropriately designated with markers upon a series of throws of the dice; and, a winner is determined by the first player to complete a required number of such locations each one of which has an assigned value for calculating a score. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 61/356,435 filed Jun. 18, 2010, which is incorporated by reference herein in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to the production of gases from biomass and solar energy.
[0004] 2. Background and Related Art
[0005] Implementation of the invention relates to altering the electrical properties of fluids while in a transition phase flowing through a specifically designed tube and capturing and storing electrolytic generated energy. This current is drawn and utilized to power a modified photonic galvanic cell during nighttime and clouded days, thereby increasing the production of electrolytic generated elemental hydrogen and oxygen which can be used in a fuel cell.
[0006] A photosynthetic dependant living organism biomass suspended in a life supporting liquid environment depends upon an internal electrical charge as part of the photosynthetic process to support growth and reproduction. These microorganisms consume nutrients consisting of a variety of organic minerals found within their liquid environment. These consumed minerals allow the individual microorganism cells to be electrically responsive. The microorganism cells therefore are conductive and as such possess positive and negative polarities. Furthermore the microorganisms' liquid environment itself is electrically conductive and is considered an electrolyte solution due to the mineral and chemical content in solution; its polarity fluctuates in nature in response to environmental changes or can be altered when artificially created.
[0007] Some types of photosynthetic microorganisms are capable of absorbing and retaining electrical voltage similar to a voltage capacitor which stores and discharges voltage once a full capacity has been reached. In the case of microorganisms suspended within a conductive liquid medium, once the limit of stored voltage has been achieved, individual cells release their excess voltage into the liquid environment. This charge and discharge activity can be measured with oxygen reduction potential, pH and conductivity meters and reflects the overall electrical state of the growth medium as the photosynthetic organisms uptake minerals, fix these minerals, and discharge gases as part of the photosynthetic and respiration processes.
[0008] The Calvin cycle represented in the overall formula: 3 CO 2 +9 ATP+6 NADPH+6H+→C 3 H 6 O 3 -phosphate+9 ADP+8 Pi+6 NADP+ +3H 2 O, demonstrates the fixing of Hydrogen protons (H+) to create carbohydrate. There has been a lot of attention paid to cellular hydrogen extraction as a potential for fuels and fuel cells.
[0009] Extraction of hydrogen from algae has focused principally on alteration of the chemical properties of algae in order to extract fixed hydrogen from the cell. One process requires genetic modification to overcome the perceived problems of oxygen hindering the production of hydrogen. The enzyme that actually releases the hydrogen, a reversible hydrogenase, is sensitive to oxygen. The process of photosynthesis produces oxygen, therefore normally stopping hydrogen production very quickly in green algae. Various genetic approaches attempt to create O 2 -tolerant mutant versions to result in a commercial H 2 -producing system that is cost effective, scalable to large production, non-polluting, and self-sustaining. Other methods, such as sulfur deprivation, do release hydrogen, but have not proven to be viable as one has to then recombine sulfur to ensure sustained growth.
[0010] Other processes utilize acids and heat to extract hydrogen from biomass. Still other methods using bases as reactants for the production of hydrogen. These methods involves the use of redox chemistry to create hydrogen. While chemical modification can result in the creation of hydrogen, such processes are constrained as large-scale production methods due to difficulties in removing the chemicals as part of an integrated production system. The bases and acids flocculate the biomass rendering it useless for further growth and contaminate the growth medium for reuse. Photosynthetic species, such as algae, can store a large amount of pure hydrogen; however, the method of extraction of elemental hydrogen is dependent on a pyrolysis method for the use of this gas which is not extracted from the biomass prior to use. Thus, there are significant ongoing difficulties in obtaining hydrogen from biomass.
[0011] Generating a current within a photonic galvanic cell splits water into its constituent parts. Sun-powered photosynthetically driven biological fuel cells have been utilized for some time. In one device, an electrical fuel cell is formed using two chambers, one placed in sunlight and supplied with nutrients and microorganisms which transfer light energy or photons into chemical energy in the form of algae or carbohydrate, and the other placed in the dark where the chemical energy is released by reducing bacteria that produce compounds that release electrons. A bridge is included in the device to provide a pathway for cations and anions without a transfer of material between chambers. Electrons are released to an anode of the device by sulfites generated from sulfates by bacterial action. The energy of this action is derived from the sun and is stored as bacterial metabolites, these being fed to the bacteria to drive the reduction reaction's generating compounds that, in turn, give up electrons to an electrode element.
[0012] In photosynthesis, four photons captured by a chlorophyll pigment system with an average energy of approximately 50 Kcals per einstein (the einstein is used in studies of photosynthesis) are needed to reduce one molecule of nicotinamide adenine dinucleotide phosphate (NADPH) at approximately 53 Kcals per mole. All chlorophyll in oxygenic organisms is located in thylakoids, and is associated with PS II, PS I, or with antenna proteins feeding energy into these photosystems. PS II is the complex where water splitting and oxygen evolution occurs. Upon oxidation of the reaction center chlorophyll in PS II, an electron is pulled from a nearby amino acid (tyrosine) which is part of the surrounding protein, which in turn gets an electron from the water-splitting complex. From the PS II reaction center, electrons flow to free electron carrying molecules (plastoquinone) in the thylakoid membrane, and from there to another membrane-protein complex, the cytochrome b 6 f complex.
[0013] The other photosystem, PS I, also catalyzes light-induced charge separation in a fashion basically similar to PS II: light is harvested by an antenna, and light energy is transferred to a reaction center chlorophyll, where light-induced charge separation is initiated. However, in PS I electrons are transferred eventually to NADP (nicotinamid adenosine dinucleotide phosphate), the reduced form of which can be used for carbon fixation. The oxidized reaction center chlorophyll eventually receives another electron from the cytochrome b 6 f complex. Therefore, electron transfer through PS II and PS I results in water oxidation (producing oxygen) and NADP reduction, with the energy for this process provided by light (2 quanta for each electron transported through the whole chain). A schematic overview of these processes is provided in FIG. 7 . Therefore, the theoretical maximum conversion of photonic energy to reducing potential is approximately 25%. Tapping the energy as formed into carbohydrate leads to another reduction in the theoretical efficiency.
[0014] Although, in principle, the nature of the reactants is not limited, the fuel-cell reaction usually involves the combination of hydrogen with oxygen, as shown by Equation (1). At 25° C. and 1 atmosphere pressure, that is, standard temperature and pressure (STP), the reaction takes place with a free energy change (AG) of AG=056.69 kcal/mole, that is, 237,000 joules/mole water.
[0000] H 2 ( g )+½O 2 ( g )→H 2 O( l ) (1)
[0015] If the reaction is harnessed in a galvanic cell working at 100% efficiency, a cell voltage of 1.23 volts˜ results. In actual service such cells have shown steady-state potentials in the range 0.9-1.1 volts, with reported columbic efficiencies of the order 73-90%.
[0016] The most successful previous type is the H 2 -0 2 fuel cell of the direct or indirect type. In the direct type, hydrogen and oxygen are used as such, the fuel being produced in independent installations. The indirect type employs a hydrogen-generating unit that can use as raw material a wide variety of fuel. The reaction taking place at the anode is as in Eq. (2), and at the cathode as in Eq. (3).
[0000] 2H 2 +4OH − →4H 2 O+4 e − (2)
[0000] O 2 +2H 2 O+4 e−→ 4OH − (3)
[0017] Because of the low solubility of H 2 and 0 2 in electrolytes, the reactions take place at the electrode/electrolyte interface, requiring a large area of contact for a large electron flow. This is obtained with porous materials called upon to fulfill the following main duties: the materials must provide contact between electrolyte and gas over a large area, catalyze the reaction, maintain the electrolyte in a very thin layer on the surface of the electrode, and act as leads for the transmission of electrons.
[0018] One unmet challenge has been to produce hydrogen and oxygen from photosynthetically generated biomass, without harsh chemical alteration, genetic modification, or combined approaches, such as prokaryote and eukaryote using the power of sunlight as the preferred embodiment.
[0019] Another challenge has been the creation of a method of generating current to power the system when there is low sunlight or in the nocturnal cycle.
[0020] Present systems fail to provide scalability and low cost and cannot be incorporated into a system that continuously produces these valuable gaseous byproducts as part of a grow system where other valuable products are generated such as food and fuels.
[0021] Furthermore, the use of photosynthetic material to generate the constituent gases of fuel cells is of interest, as this type of energy (provided it was generated from photonic activity) would be a panacea for low-cost renewable energy production.
BRIEF SUMMARY OF THE INVENTION
[0022] Implementation of the invention relates to a passive apparatus for altering the dynamic properties of a fluid flowing within the apparatus by inducing turbulence while simultaneously generating an electrical charge which may be drawn and immediately utilized or stored. The apparatus includes a conduit configured from concentric tubes and electrodes and situated so as to be gravity fed with fluid from a larger container, tank, pond or other basin via a bypass tube or transfer passage. The body of the apparatus includes an outer (hereinafter referred to as primary) conduit and an inner (secondary) conduit composed of dissimilar or similar metals with high electrode potential, so as to function as a cathode/anode pair.
[0023] On their inner surfaces, these conduits are scored lengthwise with parallel spiraling grooves and/or are implanted with parallel protuberances which are curved lengthwise and in a spiral fashion so as to impart vortexial motion to the fluid flow and thus increase turbulence and surface area. Energy generated by the motion of the entrained fluid and its ionic interaction with the differential metals may be drawn as current by positive and negative terminals connected to the conduits. The fluid's electrical properties, and consequently its oxidation reduction potential (redox potential or ORP), may thereby be altered in order to optimize its adsorption of and reaction with secondary fluids. A plurality of similarly configured alternating anode and cathode conduits may be concentrically incorporated so as to potentiate both the turbulent flow induced by the spiraling inner profile of the conduits as well as the available electrical draw. The apparatus includes a plurality of terminals connected to any given anode or cathode conduit which may provide for increased electrical draw along the conduit flow. These terminals may be connected in parallel or in series. This voltage then can be stored in a battery or distributed to a load through a resistor-capacitor (RC) circuit.
[0024] This current is then stored or directly utilized by a reservoir which is used for the continuous harvesting of hydrogen and oxygen from a flowing fluid comprised of photosynthetic material in a growth medium exposed to sun or artificial light through a light delivery device comprised of a cathode and separated by a specifically designed membrane from an anode which abuts to a hydrogen collection chamber or cavity. The gases are recovered through a porting system which captures the gases for utilization in fuel cells or other end use. The use of flowing fluids mitigates heat build up and flocculation of the biomass. A method for increasing gas production utilizing pH modifiers can be re-used in the overall cultivation system.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0025] The objects and features of the present invention will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. Understanding that these drawings depict only typical embodiments of the invention and are, therefore, not to be considered limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:
[0026] FIG. 1 illustrates a sectional view of a biomass apparatus;
[0027] FIG. 2 illustrates a sectional view of an anode, membrane and cathode;
[0028] FIG. 3 illustrates a frontal view of a transition apparatus with serpentine clear tubing;
[0029] FIG. 4 describes a conduit within a conduit and the vortexial motion of fluids as it flows through the conveyance;
[0030] FIG. 5 describes two differing terminal configurations to the conduits;
[0031] FIG. 6 illustrates a top view of a representational system; and
[0032] FIG. 7 illustrates processes associated with the PS II and PS I complexes.
DETAILED DESCRIPTION OF THE DRAWINGS
[0033] FIG. 1 : Illustrates a reservoir 2 which provides storage and confinement for a liquid dependent photosynthesis living biomass, illuminated by sunlight 1 and introduced through a conduit 3 and evacuated in a continuous flow through a conduit 5 . These organisms provide a voltage catalysis for the release of electrons which radiate through an electrolyte capable liquid and migrates through the liquid towards an opposite polarity cathode 4 . As these electrons pass through the cathode 4 , the biomass liquid environment is approximately ninety percent blocked from passing by a membrane 6 but moisture is still allowed to soak into the membrane 6 which provides a pathway for transiting electrons to pass towards an anode 8 . Upon electron transfer through the circuit, a decomposing of the liquid environment in contact with the anode 8 is broken down from a liquid compound into its elements of H 2 and O 2 . Adjoining the anode 8 is an open chamber 10 where accumulating hydrogen atoms are collected through a port 9 as well as oxygen atoms through a port 7 .
[0034] FIG. 2 : Illustrates a single cathode 4 membrane 6 and anode 8 circuit which potentially could be placed in series to allow a scalable production rate of H 2 and O 2 to be harvested. The cathode 4 and anode 8 include a fine wire mesh that allows adsorption of the liquid environment into the membrane 6 . This adsorption provides a path for flowing electrons 12 to transit through and to the anode 8 and where as the anode 8 being considered the negative side of the circuit, allows the positively charged hydrogen atoms to collect and accumulate. The cathode 4 includes a top-mounted electrode 11 which can be connected to an electrical priming device such as the modified conduit or an intermediary battery, likewise the anode 8 includes a top-mounted electrode 13 which can be connected to a modified conduit or intermediary battery terminal. Harvest is allowed from an adjoining enclosed open chamber 10 as illustrated in FIG. 1 .
[0035] FIG. 3 : Illustrates a design to increase contact area of the biomass and sunlight by flowing through a serpentine design in the primary reservoir 2 as introduced through port 3 and evacuated through port 5 .
[0036] FIG. 4 : Illustrates a conduit 18 within a conduit 14 and the vortexial motion 16 of fluid 15 as it flows 17 through the conveyance.
[0037] FIG. 5 : Illustrates a conduit 18 within a conduit 14 and the vortexial motion 16 of fluid 15 as it flows 17 through the conveyance modified by ridges or protuberances 22 and whose captured current is drawn from electrodes 19 and 20 with a possible connection in parallel 21 .
[0038] FIG. 6 : Illustrates a complete system where a spur is drawn off from bioreactor 31 through a conduit 32 and returned through a conduit 33 . The fluid is entrained by gravity through the ionic transfer conduit 3 where current is drawn through wires 34 , 35 and stored through an RC circuit and/or battery 36 . The current is then transferred to cathode 4 and anode 8 on the harvester 37 where hydrogen and oxygen 7 , 9 are collected as a result of the flowing biomass drawn and flowed through the harvester 37 .
DETAILED DESCRIPTION OF THE INVENTION
[0039] A description of embodiments of the present invention will now be given with reference to the Figures. It is expected that the present invention may take many other forms and shapes, hence the following disclosure is intended to be illustrative and not limiting, and the scope of the invention should be determined by reference to the appended claims. The following discussion is provided solely to assist the understanding of the reader.
[0040] The optimal condition for a photosynthetically driven fuel cell would be one in which the cells collecting sunlight had as their genetic-based biochemical directive that most of the photonic energy captured within the chloroplasts of the cells would be exported from within the living cells to outside of the cell organism, where it could be acted upon without further catabolism by any other organism to produce electrons with a negative standard reduction potential as close as possible to hydrogen (−0.42 volts).
[0041] Oxygen (+0.82 volts) produced by the water-splitting activity of photosynthesis would constitute a readily-available source of oxidant, and should be thought of as the oxidant of choice for accepting electrons at the cathode, whether the cathode is separated from the living cells to which oxygen is delivered, or is spatially set among the cells to which oxygen diffuses.
[0042] To demonstrate biomass voltage as a result of the redox process, a simple test was conducted to determine the voltage and conductivity of a 500 mg dried alga-mass as follows:
[0043] Natural Biomass Voltage: +110 mv*Conductivity Value: +6.08
[0044] In respiration and photosynthesis processes by which living cells produce or use energy, a change within the liquid medium occurs which is reflected in the metric pH (potential Hydrogen). As pH is a measurement for the potential of hydrogen ionic value in an aqueous solution, the reduction potential is a measure of the tendency of the solution to either gain or lose electrons when it is subject to change by introduction of a new species. A solution with a higher (more positive) reduction potential than the new species will have a tendency to gain electrons from the new species (i.e. to be reduced by oxidizing the new species) and a solution with a lower (more negative) reduction potential will have a tendency to lose electrons to the new species (i.e. to be oxidized by reducing the new species). Just as the transfer of hydrogen ions between chemical species determines the pH of an aqueous solution, the transfer of electrons between chemical species determines the reduction potential of an aqueous solution. Like pH, the reduction potential represents an intensity factor. It does not characterize the capacity of the system for oxidation or reduction; in much the same way that pH does not characterize the acidity. As pH value increases or decreases ORP will decrease or rise. For our purposes, ORP is the measurement of the electrical value of the state of an organic species in the overall growth medium as it acquires or donates electrons as part of the photosynthetic process. Oxygen Reduction Potential or redox is measured in millivolts, (mv) or Eh (1 Eh=1 mv).
[0045] To demonstrate the relationship between pH and the corollary ORP value, the following test was conducted using a 500 mg per liter density of Nanochloropsis algae biomass within a liquid growth medium defined for our purposes as the water and nutrient mineralization typically consisting of (by volume of concentrate): Fe 1.3%, Mn 0.034%, Co 0.002%, Zn 0.0037%, Cu 0.0017%, Mo 0.0009%, N 6.0%, Phosphate (P2O5) 2.0%, B1 0.07%, B12 0.0002%, Biotin 0.0002%, specifically: Ferric Chloride, EDTA, Cobalt Chloride, Zinc Sulfate, Copper Sulfate, Manganese Chloride, Sodium Molybdate Sodium Nitrate, Monosodium Phosphate, Thiamine, Hydrochloride (Vitamin B1), Vitamin B12, Biotin. In a salt water solution of 32 ppt and specific gravity of 1.02 at 82 F
[0000]
Starting pH: 8.6
Starting ORP: +101 mv
pH: 8.0
ORP: +153 mv
pH: 7.5
ORP: +167 mv
pH: 7.0
ORP: +174 mv
pH: 6.5
ORP: +179 mv
pH: 6.0
ORP +184 mv
[0046] As clearly indicated, as the pH level dropped the ORP raised, reflecting an increase in the electrical potentials of the biomass and its liquid medium.
[0047] A system based on pH and more precisely ORP fluctuations of a photosynthetic organism could allow transitioning electrons released to accumulate and produce enough electrical energy to alter the liquid medium environment from a compound into the elemental of H 2 and O 2 through electrolysis. The electrolysis process engages when electrons are released into the liquid medium by incoming sunlight photons under the general chemical reversible formula: (AB+HOH AH+BOH)
[0048] A primary test was conducted to show if a biomass in suspension flowing through a modified conduit could generate enough voltage to engender the process of electrolysis so as to increase production of gases in a photonic electrolysis device.
[0049] A second test was performed to see if similar results could be reproduced during a natural biomass dark cycle.
[0050] A third test was conducted to show if a liquid algae biomass had the electrical potential to chemically alter the liquid medium in a transition and if so, capture and measure the amount of hydrogen and oxygen released during direct sunlight exposure.
[0051] Test 1: Conduit Test: Bench Tests Results:
[0052] The prototype: a four foot long primary conduit with a two inch diameter outer wall and a equidistantly placed secondary (inner) conductive conduit was designed to provide a fluid flow pathway between the inside wall of the primary conduit and outside wall of the secondary conduit. The inner walls of both conduits, functioning as anode and cathode, were scored and set with a protruding silicone ridge spiraling throughout the length of the inner walls so as to impart a vortexial motion to the flow. Water was flowed through at differing speeds with the use of a simple recirculating pump for testing purposes.
[0053] Protocols:
[0054] The results were analyzed using the following instruments: Milwaukee SM500 ORP Meter, New MW500 and a Northern Industrial Digital Multifunction Voltmeter. Temperature +/−70 F OriginOil: ORP Testing Date: Apr. 5, 2011
[0055] Subtest A: Filtered Water:
Salinity: 0 Specific Gravity: 1000
[0056] Starting Static Voltage: 0.084 volts Oxygen Reduction Potential: +262 mV
Low Flow Rate: 1 liter per 20 seconds High Flow Rate: 4 liters per 60 seconds
Low Flow Rate Voltage: 1.442 volts High Flow Rate Voltage: 1.402 volts
Low Flow Rate ORP: +190 mV High Flow Rate ORP: +189 mV
[0057] Subtest B: Tap Water:
Salinity: 0 Specific Gravity: 1000
[0058] Starting Static Voltage: 0.044 volts Oxygen Reduction Potential: +265 mV
Low Flow Rate: 1 liter per 20 seconds High Flow Rate: 4 liters per 60 seconds
Low Flow Rate Voltage: 1.394 volts High Flow Rate Voltage: 1.364 volts
Low Flow Rate ORP: +203 mV High Flow Rate ORP: +202 mv
[0059] Subtest C: Salt Water:
Salinity: 16 Specific Gravity: 1.012
[0060] Starting Static Voltage: 001 volts Oxygen Reduction Potential: +261 mv
Low Flow Rate: 1 liter per 20 seconds High Flow Rate: 4 liters per 60 seconds
Low Flow Rate Voltage: 1.460 volts High Flow Rate Voltage: 1.425 volts
Low Flow Rate ORP: +150 mV High Flow Rate ORP: +105 mV
[0061] Subtest D: Nannochloropsis Bio-Algae
Salinity: 36 Specific Gravity: 1.026
[0062] Starting Static Voltage: −007 volts Oxygen Reduction Potential: 120 mv
Low Flow Rate: 1 liter per 20 seconds High Flow Rate: 4 liters per 60 seconds
Low Flow Rate Voltage: 1.297 volts High Flow Rate Voltage: 1.272 volts
Low Flow Rate ORP: +174 mV High Flow Rate ORP: +188 mV
[0063] Test 2:
[0064] A 250 ml reservoir with a clear window opening under which was positioned parallel to each other a sequence consisting of a cathode mesh, a membrane and an anode mesh abutting a hydrogen harvest chamber to demonstrate when the reservoir was filled with a Nanochloropsis ( N. oculata ) biomass in aqueous suspension, confirmed the process of chemical electrolysis and the generation of elemental H 2 and O 2 .
[0065] The following is the test procedures utilized to determine whether this reaction would take place in the absence of light and or if direct sunlight exposure had any affect on energy transfer over the 4 hour test duration.
[0066] A hydrogen detection meter which measures in micro to milli moles elemental Hydrogen was used for hydrogen detection.
[0067] Brief Result Summary: A direct sunlight cycle did produce an overall better averaged as opposed to a darkness cycle.
Example
[0068] H 2 /O 2 production rate was measured when the reservoir was covered with a black cover to replicate an algae dark cycle, as follows:
[0000] Start Time: 10:00 AM Bio Type: Nanochloropsis salt water species
Dry Cell Voltage: 24.3 mv Ambient Temperature: 70.7 F Bio pH: 8.88
[0069] Bio ORP: −056 Wet Cell Starting Voltage: 23.3 mv & rising
Power Input: Volts: 3.7 Amps: 0.216 Duration: 30 seconds
Starting Voltage in Cell after Input: 0.848 mv
Dark Duration of Operation: 10 AM to 2 PM/4 hours
Readings:
[0070]
[0000]
10:00 AM (start):
68 Micromoles
Cell Voltage:
.251 mv
10:30 AM
132 Micromoles
Cell Voltage:
.179 mv
11:00 AM
132 Micromoles
Cell Voltage:
.134 mv
11:30 AM
122 Micromoles
Cell Voltage:
.134 mv
12:00 PM
112 Micromoles
Cell Voltage:
.112 mv
12:30 PM
102 Micromoles
Cell Voltage:
.090 mv
1:00 PM
84 Micromoles
Cell Voltage:
.076 mv
1:30 PM
74 Micromoles
Cell Voltage:
.071 mv
2:00 PM
68 Micromoles
Cell Voltage:
.064 mv
Ending Hydrogen
68 Micromoles
Ending Cell Voltage:
.064 mv
Micromoles:
[0071] Test 3:
[0072] H 2 /O 2 production rate were measured when the reservoir was exposed in direct sunlight to replicate a natural algae light cycle, as follows:
Start Time: 10:30 AM
[0073] Bio Type Nanochloropsis salt water species. Dry Cell Voltage: 06.3 mv
Bio pH: 9.0 Ambient Temperature: 73 F Bio ORP: −065
Wet Cell Starting Voltage: −07.2 mv
[0074] Power Input burst:
Volts: 3.5 Amps: 0.215 Duration: 30 seconds
Starting Voltage in Cell after Input: 902.mv and rising
Light Duration of Operation: 10:30 AM to 2:30 PM/4 hours
Readings:
[0075]
[0000]
10:30 AM (start):
160 Micromoles
Cell Voltage:
.247 mv
11:00 AM:
170 Micromoles
Cell Voltage:
.220 mv
11:30 AM
160 Micromoles
Cell Voltage:
.154 mv
12:00 PM
154 Micromoles
Cell Voltage:
.105 mv
12:30 PM
150 Micromoles
Cell Voltage:
.089 mv
1:00 PM
88 Micromoles
Cell Voltage:
.070 mv
1:30 PM
60 Micromoles
Cell Voltage:
.064 mv
2:00 PM
50 Micromoles
Cell Voltage:
.064 mv
2:30 PM
16 Micromoles
Cell Voltage:
.063 mv
Ending Hydrogen
16 Micromoles
Ending Cell Voltage:
.063 mv
Micromoles:
[0076] Result Summary: Average production rate during each ½-hour segment of Light Cycle yielded 112 micromoles of hydrogen.
[0077] Average production rate during each ½-hour segment of Dark Cycle yielded 86 micromoles of hydrogen.
[0078] Accordingly a system and apparatuses are herewith described comprised of an ORP-modifying and current-capture conduit in the first instance which is electrically connected to a photonic-driven apparatus which creates electrolysis to capture hydrogen thereby creating a diurnal and nocturnal system.
[0079] In the primary embodiment the fluid is gravity fed through the conveyance and split laterally between a primary conduit 14 whose inner surface has been tooled so as to create raised parallel ridges, protuberances or depressions 22 which spiral down the length of the conduit thereby imparting a vortexial motion to the flow and increasing its effective surface area while decreasing its potential energy and pressure (Bernoulli effect), and a secondary conduit 18 . The secondary conduit 18 is of equal length and is similarly configured, but with a smaller circumference which allows it to nest within the primary conduit 14 , allowing adequate room for fluid flow without. In practice and scale considerations, the gap between the primary conduit's inner surface and the outer surface of the secondary conduit 18 can vary from approximately 1 mm to approximately 10 cm or more depending on factors such as type of fluid, flow rates, desired ORP modification, etc. The gap between the primary conduit 14 and the secondary conduit 18 , however sized, remains consistent throughout the length of the overall conduit combination.
[0080] Alternatively, the secondary (or central, in the case of plurally layered conduits) conduit 18 may in fact be a rod, and not a tube, provided it is connected to the RC circuit via electrode as described above and made of a material with sufficient electrical potential vis a vis its proximate conduit 14 .
[0081] The primary 14 and secondary 16 conduits are respectively composed of or lined with dissimilar or in some cases similar metals, metal doped plastics or fiber compositions such as those commonly used in galvanic cells, such as zinc/copper, aluminum/nickel, stainless steel to stainless steel or other pairings of conductive metals. The metal choice will depend on the type of reactions desired, conductivity, reactivity to fluids, corrosion, wear and other considerations. It is understood that many forms of metal deposition methods can be used for coatings of the anode and cathode conduits 14 , 18 beyond pure or compound metals, including, but not limited to, metals deposed onto a substrate through thermal, vapor and chemical vapor deposition of nano and doped nano metals for example.
[0082] In a further embodiment, to the primary conduit 14 and secondary conduit 16 , additional conduits with similar configurations but correspondingly smaller circumferences can be nested or concentrically implanted, provided each succeeding conduit be of opposing polarity and positioned to allow sufficient space for fluid flow between conduit layers.
[0083] To each conduit (e.g. conduit 14 and conduit 18 , or each of the nested conduits) is welded or otherwise connected a passive conductor, terminal, or electrode connecting the interior of the conduit to the exterior of the primary conduit 14 , extending through, and insulated from any intermediary conduit layers. The placement of these terminals can vary. They may be on the same radial axis or on different radial axes for example, or may be at opposite ends of a conduit, as illustrated in FIG. 5 with electrodes 19 and 20 . There can also be a plurality of terminals distributed throughout the length of the conduits, thereby increasing the points of voltage collection and ORP modification. The terminals can be placed so that the collection end on the interior of the conduit 14 projects into the fluid flow 17 , thus creating additional vortices and increasing surface area and dynamism within the fluid flow 17 . On the external ends of the terminals, connections are made to a central RC circuit which can act as a storage device through standard circuit design in order to uptake the flow-generated current. The current, should one desire, can be used as a source of energy for other purposes. This by-product which has to be bled off of the system to create the dynamic ORP shifts has value and can be used.
[0084] In the case of a plurality of conduits, the attachment of terminals will be as described previously. Each conduit will have one or more terminals welded to it, extending through, and insulated from intermediary conduit layers and terminating outside the external wall of the primary conduit 14 . These terminals are then connected to the central RC circuit, as described below.
[0085] The plurality of terminals may be connected in series, where positive to positive and negative to negative are connected to a central RC circuit or battery 36 as shown in FIG. 6 for capture of the generated voltage as energy for storage or use.
[0086] In a further embodiment, the terminals and are connected in parallel when having a plurality of open ended positive and negative terminals, a connection to an open negative to a positive terminal produces a parallel circuit which allows voltage capture which is then relayed to the central RC circuit or battery 36 for energy storage or use.
[0087] A system as shown in FIG. 6 is described a conveyance such as a trough, pipe or other means is placed close to a body of water, mixing tank or grow tank, e.g. the bio-reactor 31 , or any other vessel that serves to hold fluids and the fluid is flowed through a series of conduits 32 33 through the ORP modifier 38 as discussed above and shown in FIG. 4-5 . The conveyance can include a fluid modifier injection port. The generated current is captured through the RC circuit or battery 36 .
[0088] The system also includes an apparatus, herein referred to as the transition apparatus or harvester 37 , which contains a living photosynthesis biomass flowed through the apparatus though sealed but ported by a clear window which allows the entry of light. Sandwiched between the reservoir 2 and the harvest open chamber 10 is an array composed of the cathode 4 and the anode 8 separated by the membrane 6 , as illustrated in FIG. 1 . Adjoining and open to the anode side, the harvest chamber 10 or cavity collects the generated gases through ports 7 , 9 on the top of the transition apparatus. Although FIG. 1 shows an apparatus arranged with the anode 8 proximate the chamber 10 , an alternative apparatus includes the cathode 4 and anode 8 separated by the membrane 6 , but with the cathode 4 proximate the chamber 10 . As shown in FIG. 6 , the biomass flow through the reservoir 2 of the harvester 37 is received through conduit 3 from the ORP modifier 38 and is returned to the bio-reactor 31 or conduit 33 through conduit 5 , permitting ongoing circulation of the aqueous biomass through the entire system.
[0089] In methods according to embodiments of the invention, gases and compounds are used to alter and control electrical factors within a living biomass in order to conduct an on-going electrolysis process in their liquid growth environment.
[0090] In embodiments of the transition apparatus or harvester 37 , the apparatus includes a sealed container. The sealed container includes a port or window made of clear plastic which allows electromagnetic radiation penetration to the anode 8 and cathode 4 plates separated by the membrane 6 . The adjoining cavity or chamber 10 is connected to the anode 8 , membrane 6 , and cathode 4 array and this empty space makes contact with the anode side of the array.
[0091] The container can be constructed of a plurality of materials and sizes. The criteria for design will be resistance to weather and water tightness and various materials and methods of construction should be readily apparent from the discussion herein in conjunction with ordinary skill in the container construction art. One could anticipate a number of units constructed in a honeycomb fashion for example, which are united by conduits through which biomass is flowed. These would have the advantage of permitting swapping out any defective or failing units without affecting the whole system. In a further embodiment, these containers or transition apparatuses could be laid side by side on rafters in an enclosed building whereby light is diffused to the ports through natural light conduits such as fiber-optics or Fresnel lenses.
[0092] In some embodiments, the biomass is flowed through the reservoir in a single plane whereby the whole of the biomass is in contact with the cathode side and seeps through the membrane 6 to the anode side.
[0093] Some embodiments employ a plurality of containers nested within the main reservoir 2 or otherwise connected to the reservoir 2 to encompass the use of differing photosynthetic organisms. These nested reservoirs are connected to the anode and cathode plates either individually or through a series of conduits, or to minimize the membrane size by incorporating a plurality of plate arrays.
[0094] In other embodiments, the biomass is flowed through a sinew pattern set over the cathode 4 plate, as shown in FIG. 3 . Utilizing such a serpentine design may increase surface area and the amount of algae biomass in contact with the cathode 4 . A further advantage is an increase in porting which mitigates the pooling of gases on the plates. The porting of the gases occurs on the anode side to evacuate oxygen generated by the electrolysis current. This porting reduces the accumulation of oxygen present after oxygen generation by the electrolysis current, as excess oxygen can act as a hydrogen production inhibitor; furthermore, the oxygen can be used in a recombinant form for the creation of electricity in a fuel cell.
[0095] The reactions take place at the electrode/electrolyte interface and require a large area of contact for a large electron flow. It is anticipated that the porting will be designed to capture the majority of the gas concentrated on the plate through a system of ridges and protuberances along the cathode 4 plate. These protuberances and ridges also aid in the collection of gases if the plates are somewhat angled to preclude pooling of gases. As a further embodiment, the plates can be placed slightly askew of parallel so as to abet the transition and flow of gases upwardly.
[0096] To those versed in this art, it is reasonable to assume that a plurality of exhaust ports can be strategically placed as the size of the array expands. These ports can be placed at differing points of the array to mitigate pooling of gases and enhance evacuation and capture.
[0097] One important consideration in the design of the system is the material used to permit the introduction of light. The use of plastics as the window plate may assist in controlling of the dynamic ranges of the electromagnetic spectrum allowed to enter the apparatus. The range of the electromagnetic spectrum of importance may be considered to be in the approximately 280 nm to 2500 nm range which encompasses UVA and B at the low-end and near-Infra red at the top. Retaining certain wavelength values while mitigating others is of importance. For example, in the UV bandwidth, UVA (320-400 nm) and UVB (280-320 nm) are desirable, whereas UVC (100-280 nm) is considered germicidal and would harm the living culture.
[0098] In some embodiments, Fluoropolymers such as FEP and polyimides such as Kapton, PTFE, PVDF, FEP, and PEEK™ are plastics that can be used which avoid photo-oxidation of the plastic while retaining the transmission of valuable UV rays to the matrix. Other embodiments include colorizing the plastics with fluorescent whitening agents (FWA) as these increase conductivity and assist in transforming some UV light to the blue spectrum (˜400 nm), which is desirable for promoting photosynthesis. There is evidence that portions of the upper end of the spectrum (infra-red (IR), medium and far-infra red) can excite and enhance the production of conductivity in the growth medium.
[0099] Some embodiments embrace the utilization of materials such as germanium, silicone, sapphire and/or nano-coated materials thereof that improve IR which increase production of energy since IR acts as an excitant in water through its absorption by the growth medium as heat. In certain embodiments, these nano-structured coatings can be applied to the surface of the plate reflecting inwardly sunlight or artificial light that mimics the electro-magnetic frequency of sunlight.
[0100] In a further embodiment, a reflecting surface such as a mirror or Mylar coated reflective surface is placed behind the anode section to further enhance light back towards the array. Testing with this method has shown increased production of gases without an excessive increase in heat as the flowing biomass acts as a cooling agent.
[0101] In some embodiments, a cathode 4 and anode 8 mesh herein referred to as the plates are separated by the membrane 6 . The biomass is flowed towards the cathode side and a residual amount transpires through the membrane 6 towards the anode side where the H 2 is harvested in a dry cavity, chamber or collection tank 10 .
[0102] As an example of the types of electrode configurations mentioned above, some embodiments incorporate an electrode set which has at least two parallel plate electrodes. If more than two such plate electrodes are used, anode and cathode plates alternate to make up the set. If desired, non electrode plates may be installed between successive electrode plates to serve as equipotential surfaces, thereby assisting in maintaining reasonably uniform electric fields between successive electrodes. The spacing between successive electrode plates is chosen such that appropriate electric field strengths and/or currents are generated between the electrodes. In particular illustrative cases, the electrode spacing is on the order of about 0.05 to 1.0 cm, 1.0 to 2.0 cm, 2 to 5 cm, 5 to 10 cm, 10 to 20 cm, 20 to 50 cm, 0.5 cm to 50 cm, or 5.0 to 50 cm.
[0103] The electrode plates will usually be sufficiently thick to have sufficient mechanical strength considering the material(s) of which to plate is constructed to allow normal handling without problematic deflection of or damage to the plate. In certain illustrative cases, the plate thickness will be on the order of about 0.2 to 0.5 mm, 1.0 to 2.0 mm, 2.0 to 5.0 mm, or 0.2 to 2.0 mm. The electrode plates surface can be chosen in view of several parameters, e.g. capacity, desired fluid residence time, and/or desired processing capacity. In particular examples, the individual electrode plates have exposed active areas of 1.0 to 5 cm 2 , 5.0 to 10.0 cm 2 , 10 to 50 cm 2 , 50 to 200 cm 2 , 200 to 1000 cm 2 , or even more. Depending on the application (e.g. considering space available in a desired location and/or for providing appropriate residence time for medium flowing through the electrode set), different shapes of electrode plates may be desirable, e.g., commonly rectangular, which may be square or non-square rectangular. Non-square rectangular plates may, for example, have lengths and widths in a ratio of about 1.1:1 to 1.5:1, 1.5:1 to 3:1, 3:1 to 6:1, 6:1 to 10:1, 10:1 to 20:1, or greater than 20:1.
[0104] Electricity is generated due to electric potential difference between two electrodes. This potential difference is created as a result of the difference between individual potentials of the two metal electrodes with respect to the electrolyte. These values and the metals used are known to those practicing the art and are reiterated here to encompass all permutations possible in the design of the mesh plates and coatings following the formula: E° cell=E° cathode−E° anode where E° anode is the standard potential at the anode and E° cathode is the standard potential at the cathode as given in the table of standard electrode potentials, which is incorporated as referenced in Table 1:
[0000]
TABLE 1
STANDARD ELECTRODE POTENTIALS
Half-Reaction
V
Li + + e − Li
−3.04
K + + e − K
−2.92
Ba 2+ + 2e − Ba
−2.90
Ca 2+ + 2e − Ca
−2.87
Na + + e − Na
−2.71
Mg 2+ + 2e − Mg
−2.37
Al 3+ + 3e − Al
−1.66
Mn 2+ + 2e − Mn
−1.18
2H 2 O + 2e − H 2 (g) + 2OH −
−0.83
Zn 2+ + 2e − Zn
−0.76
Cr 2+ + 2e − Cr
−0.74
Fe 2+ + 2e − Fe
−0.44
Cr 3+ + 3e − Cr
−0.41
Cd 2+ + 2e − Cd
−0.40
Co 2+ + 2e − Co
−0.28
Ni 2+ + 2e − Ni
−0.25
Sn 2+ + 2e − Sn
−0.14
Pb 2+ + 2e − Pb
−0.13
Fe 3+ + 3e − Fe
−0.04
2H + + 2e − H 2 (g)
0.00
S + 2H + + 2e − H 2 S (g)
0.14
Sn 4+ + 2e − Sn 2+
0.15
Cu 2+ + e − Cu +
0.16
SO 4 2+ + 4H + + 2e − SO 2 (g) + 2H 2 O
0.17
Cu 2+ + 2e − Cu
0.34
2H 2 O + O 2 + 4e − 4OH −
0.40
Cu + + e − Cu
0.52
I 2 + 2e − 2I −
0.54
O 2 (g) + 2H + + 2e − H 2 O 2
0.68
Fe 3+ + e − Fe 2+
0.77
NO 3 − + 2H + + e − NO 2 (g) + H 2 O
0.78
Hg 2+ + 2e − Hg (1)
0.78
Ag + + e − Ag
0.80
NO 3 − + 4H + + 3e − NO (g) + 2H 2 O
0.96
Br 2 + 2e − 2Br −
1.06
O 2 (g) + 4H + + 4e − 2H 2 O
1.23
MnO 2 + 4H + + 2e − Mn 2+ + 2H 2 O
1.28
Cr 2 O 7 2− + 14H + + 6e − 2Cr 3+ + 7H 2 O
1.33
Cl 2 + 2e − 2Cl −
1.36
Au 3+ + 3e − Au
1.50
MnO 4 − + 8H + + 5e − Mn 2+ + 4H 2 O
1.52
Co 3+ + e − Co 2+
1.82
F 2 + 2e − 2F −
2.87
[0105] In some embodiments, the anode 8 is coated with a dark color to increase absorption of the light spectrum and create UV absorbance. An example of such a coating is dimethylbenzoyl, titanium dioxide and zinc phosphate and/or combinations thereof. A commercial example of this coating is available under the Rustoleum brand. In some embodiments, the use of carbon plates has shown good result as generating electricity sufficient to cleave water without imparting heavy metals, which is an attribute that has advantage in a live growth culture system.
[0106] Further embodiments include a grouping of metals such as are found in the lanthanum group of the periodic chart specifically cesium and barium coated metals. Further embodiments include the use of metals such as platinum, nano-platinum, palladium, and other metals known to art for their long life and resistance to wear, although such materials have higher costs. Additional embodiments include the use of nano or nano-doped material through annealing, thin film vacuum deposition onto base metals, with the goal of lowering costs, extending plate life and increasing voltage thereby increasing H 2 production.
[0107] The fact that redox occurs simultaneously in a cell favors the use of a cell separator. Cell separators are separate the products obtained at the two electrodes in a cell, e.g. in the electrolytic production of hydrogen and oxygen by water electrolysis where the requirement of safety in operation is important. Overall the material used as separators are varied and may simply be micro-porous separators or may possess specific ion transport characteristics. Permeable membranes permit the bulk flow of liquids through their structure and are thus non-selective regarding transport of ions or neutral molecules. In electrochemical processes these are referred to as diaphragms.
[0108] In some embodiments, the cell separator is placed midway between the anode 8 and the cathode 4 . This spacing can vary and spacers may be placed on the four corners of the inner plates to separate the plates and allow the membrane 6 to float between the plates. This separation provides access to the membrane 6 should it require maintenance or replacement. It is also anticipated that the spacing would allow more or less biomass to flow through the cathode 4 to migrate towards the anode 8 . This spacing can be, for example, as little as 3 mm to 15 mm.
[0109] In some embodiments, the membrane is composed of electrolytic capacitor paper; however the use of the following materials is incorporated as further embodiments depending on factors required such as costs, temperature and durability: asbestos fibers and glass fibers, PTFE paper felt, fiber, polypropylene asbestos sheet and composite fiber sheet, PVC asbestos on metal screen, copolymers ceramics coated asbestos, styrene AL2O3, SiO 2 , Nafion ZrO 2 , and porous PTFE glass fibers.
[0110] Embodiments also include a terminal soldered onto or otherwise electrically connected to the anode 8 and cathode 4 which terminates outside of the transition box. These terminals can be connected to a battery or other circuitry which stores or uses electricity created from a source within the growth system as seen above.
[0111] In a further embodiment, the array, cathode 4 , membrane 6 , and anode 8 may be stacked in a manner such as to increase the contact area with biomass. Such embodiments may be used with the use of lighting systems such as fiber-optic light delivery or other methods of light diffusion and distribution to the cathode anode array through the biomass.
[0112] As discussed above, embodiments of the invention relates to the flow of photosynthetic organisms through the transition apparatus. Our testing has focused on two primary species of organisms: Nanochloropsis ( N. oculata ) in a salt water solution and Synechocystis sp. PCC6803, a freshwater cyanobacterium.
[0113] In some embodiments, the use of algae (eukaryote) water species includes species known to the art as high value organism, that is organisms that can be grown easily and have valuable by-products such as food or fuel. The main four groups are broadly named: red algae (Rhodophyta), brown algae (Heteromontophyta), green algae (Chlorophyta) and diatoms (Diatomaceae). In further embodiments, the use of certain photosynthetic bacterium is included such as cyanobacteria as they have shown similar electrical value when used within the transition apparatus. In further embodiments, fungi which are non-photosynthetic eukaryotes or chemoorganotrophs, such as yeasts can be used. The use of yeasts in the transition apparatus is practical as a salt bridge to capture excess oxygen and release CO 2 which algae require for growth.
[0114] In some embodiments, the use of organic minerals increases growth and adds mineral ionization values to the growth mixture. These minerals include the following, but are not limited solely to these as differing species require specialized admixtures and mineralization to maintain growth: ferric chloride, EDTA, cobalt chloride, calcium, magnesium, iron, zinc sulfate, copper sulfate, manganese chloride, sodium molybdate, sodium nitrate, monosodium phosphate, thiamine, hydrochloride (vitamin B1), vitamin B12, and biotin.
[0115] In some embodiments, the transition apparatus is connected to an algae grow system through a system of piping and pumps sufficient to flow a minimal amount of growth material or portion of the liquid for use in the gaseous extraction system which is then processed in a fuel cell for the generation of electricity.
[0116] As mentioned above, ORP can be adjusted by the manipulation of the pH; where RO or distilled water is considered neutral pH of 7. At pH levels below 7, the matrix contains a plurality of protons (H+) in an amount exceeding the number of OH− ions. At a pH level of 7, the matrix is considered neutral and to have a balance between protons and OH− ions. At pH levels above 7, the matrix now contains a plurality of OH− ions in an amount exceeding the number of protons (H+). Thus, the pH scale is a relative scale of anion and cation balance. The differences between H+ and OH— concentrations is the acidity or alkalinity of the liquid environment housing the living biomass.
[0117] When CO 2 is introduced to the matrix, pH decreases and acidifies the growth medium thereby increasing the proton (H+) content of the matrix which enhances hydrogen migration to the anode 8 . When the pH level is increased, the growth medium becomes more alkaline thereby increasing the hydroxyl value of the water (OH−) causing a decrease in free hydrogen to migrate to the anode(s) 8 . During a photosynthesis light cycle the cells are actively in a growth mode and require an intake of CO 2 to complete the photosynthesis cycle, so this chemical modification of adding CO 2 is not deleterious to the system as a whole and provides an integrated solution.
[0118] To facilitate electrolysis, three main components are provided: 1) a liquid capable of ionic transfer, 2) a source of electrical input and 3) electrically conductive materials. This combination of circumstances allow an electron reduction and transfer to occur and in the case of embodiments of the present invention, between the anode 8 and the cathode 4 separated by the close-tolerance membrane 6 .
[0119] Testing was conducted using a measured CO 2 injection based on pH every hour to determine if additional hydrogen production could be achieved and to monitor either an increase or decrease of biomass electrical values. This testing validates the ORP and pH factors as a metric for electrical value control as illustrated in the following durational test.
[0000] Table 2, below, illustrates a method which allows voltage manipulation to occur within a living liquid photosynthesis dependent biomass. Oxygen Reduction Potential, (ORP) and Potential Hydrogen Ion Concentration, (pH) factors can be manipulated within a living biomass liquid environment to create an electrolysis process.
[0000]
Starting Data:
Starting Time: 10:00 AM Bio Type: Nanochloropsis
Dry Cell Voltage: −37.7 mv Bio pH: 8.52 Ambient Temperature: 72.3 F.
Bio ORP: +100 mv Bio Electrical Conductibility: +7.39
Bio Conductivity Factors: 73.9%
Wet Cell Starting Voltage: −38.9 mv
Power Input:
Volts: 3.6 Amps: .216 Duration: 30 seconds
Voltage in Cell after Power Input: .940 mv
10:15AM 68 Micromoles
800 mv
(dropping)
10:30 AM 150 Micromoles
414 mv
11:00 AM 136 Micromoles
168 mv
2 minute CO 2 injection: 160 Micromoles
195 mv
pH: 6.00
11:30 AM 146 Micromoles
148 mv
pH: 6.19
12:00 PM 116 Micromoles
114 mv
pH: 6.22
1 minute CO 2 injection: 122 Micromoles
133 mv
pH: 6.04
12:30 PM 98 Micromoles
106 mv
pH: 6.01
1:00 PM 84 Micromoles
85.2 mv
pH: 6.05
1 minute CO 2 injection: 88 Micromoles
130.2 mv
pH: 5.62
1:30 PM 54 Micromoles
99.0 mv
pH: 5.64
2:00 PM 44 Micromoles
75.5 mv
pH: 5.66
1 minute CO 2 injection: 50 Micromoles
106.4 mv
pH: 5.51
Beginning pH: 8.52
Ending: 5.51
Beginning ORP: 100 m
Ending 183 mv
Beginning Biomass Electrical Conductivity: 73.9
Ending: 68.7
Beginning Bio Conductivity Factors: 7.39
Ending: 6.83
[0120] As shown in testing, when CO 2 is introduced as part of the hydrogen harvesting system, an increase in millivolts (ORP) did occur. Thus, injection of CO 2 allows for an increase in hydrogen production while pH decreased over each 30 minute segment.
[0121] One skilled in the art should readily appreciate that embodiments of the present invention are well adapted to achieving the ends and advantages mentioned, as well as those inherent therein. The methods, variances, and compositions described herein are presently representative of certain embodiments only, are exemplary, and are not intended as limitations on the scope of the invention. Changes therein and other uses will occur to those skilled in the art, which are encompassed within the spirit of the invention, as defined by the scope of the claims.
[0122] It will be readily apparent to one skilled in the art that varying substitutions and modifications may be made to the invention disclosed herein without departing from the scope and spirit of the invention. For example, variations can be made to the design, size and placement of electrodes as well as number of concentric conduits. Thus, such additional embodiments are within the scope of the present invention and following claims.
[0123] The invention illustratively described herein suitably may be practiced in the absence of any elements, limitation or limitations which is not specifically disclosed herein. For example, in each instance herein any of the terms “comprising”, “consisting essentially of” and “consisting of” may be replaced with either of the other two terms. The terms and expressions which have been employed are used as terms of description and not of limitation, and there is not intention that in the use of such terms and expression of excluding any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the invention claimed. Thus, it should be understood that although the present invention has been specifically disclosed by certain embodiments and optional features, modifications and variations of the concepts herein disclosed may be resorted to by those skilled in the art, and that such modifications and variations are considered to be within the scope of this invention as defined by the appended claims.
[0124] Also, unless indicated to the contrary, where various numerical values or value range endpoints are provided for embodiments, additional embodiments are described by taking any two different values as the endpoints of a range or by taking two different range endpoints from specified ranges as the endpoint of an additional range. Further, specification of a numerical range including values greater than the ones include specific description of each integer value within that range.
[0125] The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims, rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope. | A system includes an ionic exchange conduit through which a flow of photosynthetic biomass is drawn capturing an electrical charge which is used to alternately power a photonic activated reservoir housing a living photosynthetic biomass suspended in a flowing liquid medium which self generates an electrical charge as it migrates towards and through a cathode separated from an anode by a membrane. Upon electrical transfer through the circuit an electrolysis process begins and releases hydrogen and oxygen into enclosed atmosphere chambers where these separated gases can be captured for use in a fuel cell. | 2 |
BACKGROUND
In a well perforating operation, a perforating gun string is used to carry a perforating gun downhole into a wellbore to a desired region. The perforating gun comprises a carrier tube designed to carry a plurality of charges which are detonated to form perforations that extend outwardly in a radial direction into a surrounding formation. As the carrier tube is conveyed deeper into the wellbore, a substantial pressure differential is established between the high pressure external well environment and the interior of the carrier tube. The high differential pressure increases both the collapse tendency and the leak potential of the carrier. Following perforation, the differential pressure also can drive well fluid into the perforating gun and cause a detrimental pressure pulse which propagates through the wellbore fluid.
SUMMARY
In general, the present disclosure provides a methodology and system which facilitate a perforation operation. A perforating gun carrier is combined with a pressure enhancement mechanism. The pressure enhancement mechanism enables a controlled increase in pressure within the perforating gun as the perforating gun carrier is delivered into a higher pressure environment. The increase in internal pressure counters the buildup of a pressure differential to the degree desired for a given perforating gun carrier.
BRIEF DESCRIPTION OF THE DRAWINGS
Certain embodiments will hereafter be described with reference to the accompanying drawings, wherein like reference numerals denote like elements. It should be understood, however, that the accompanying figures illustrate only the various implementations described herein and are not meant to limit the scope of various technologies described herein, and:
FIG. 1 is a schematic illustration of an example of a perforating gun string, according to an embodiment of the disclosure;
FIG. 2 is an illustration of a perforating gun carrier, according to an embodiment of the disclosure;
FIG. 3 is an illustration of another example of a perforating gun carrier, according to an embodiment of the disclosure;
FIG. 4 is a schematic illustration of a perforating operation, according to an embodiment of the disclosure;
FIG. 5 is an illustration of a perforating gun carrier on a perforating gun string during an initial stage of conveyance downhole, according to an embodiment of the disclosure;
FIG. 6 is an illustration of a perforating gun carrier on a perforating gun string similar to that of FIG. 5 but during a subsequent stage of conveyance downhole, according to an embodiment of the disclosure; and
FIG. 7 is an illustration of a perforating gun carrier on a perforating gun string similar to that of FIG. 5 but positioned at a perforating region, according to an embodiment of the disclosure.
DETAILED DESCRIPTION
In the following description, numerous details are set forth to provide an understanding of some illustrative embodiments of the present disclosure. However, it will be understood by those of ordinary skill in the art that the system and/or methodology may be practiced without these details and that numerous variations or modifications from the described embodiments may be possible.
The disclosure herein generally relates to a system and methodology which can be employed to alleviate the detrimental effects of differential pressures acting on a hollow body during a perforating operation. In downhole perforating operations, for example, the perforating gun carrier is subjected to high downhole wellbore pressures which can create detrimental differential pressures between the exterior and interior of the perforating gun carrier. According to an embodiment of the present system and methodology the static pressure differential in a perforating gun carrier is reduced prior to shooting, thus reducing the collapse tendency of the carrier and also reducing the leak potential of sealing elements. The increased in-gun pressure also reduces the influx of wellbore fluid which would otherwise enter into the perforating gun carrier due to the pressure differential. Consequently, perforating gun filling and the resulting pressure pulse propagating through the wellbore fluid are eliminated or adequately reduced. Eliminating or adequately reducing the pressure pulse removes a variety of detrimental effects, e.g. excessive stresses, which would otherwise act against the well equipment.
In perforating applications, the interior pressure within the perforating gun carrier can be increased in a controlled manner to reduce or eliminate the pressure differential between the interior and the exterior of the gun carrier. By way of example, pressure in the interior of the perforating gun carrier may be increased by a pressure enhancement mechanism carried by the perforating gun string. An example of a pressure enhancement mechanism comprises an internal gas generator, such as a propellant charge. In another example of a pressure enhancement mechanism, the interior pressure may be increased through activation of a subcritical fluid, e.g. CO2, at the downhole temperature. Additionally, the interior pressure may be controlled by a pressure enhancement mechanism which releases compressed gas from a compressed gas chamber working in cooperation with the gun carrier.
In many applications, the pressurization occurs after the gun carrier is placed in a wellbore. For example, the controlled pressurization can be executed downhole on a continuous basis as the perforating gun carrier is lowered to a desired perforating region along a surrounding formation. The pressurization also may be performed within the perforating gun carrier in discrete steps, e.g. at sequential, discrete locations along the wellbore, as the perforating gun is conveyed downhole to the desired perforating region.
Perforating operations can be performed in many types of downhole applications and in other applications via several types of perforating guns. For example, some perforating guns comprise a perforating gun carrier, such as a perforating gun carrier tube, which is designed to hold charges that are selectively detonated to form perforations in the surrounding structures. According to an embodiment, a perforating gun string is provided with a perforating gun carrier and the carrier is conveyed downhole into a wellbore. During conveyance, pressure is increased within the perforating gun carrier via the pressure enhancement mechanism. The pressure enhancement mechanism may be carried by the perforating gun string and is designed to provide a controlled increase in pressure during the conveyance downhole.
Referring generally to FIG. 1 , an example of one type of application for facilitating a perforating operation is illustrated. The example is provided to facilitate explanation, and it should be understood that a variety of perforating gun strings and systems may be used in a variety of well related applications as well as in many types of non-well related applications in which perforations are to be formed. The perforating gun string and other structures described herein may comprise many types of components arranged in various configurations depending on the parameters of a specific perforating application.
In FIG. 1 , an embodiment of a perforating system 20 is illustrated as comprising a perforating gun carrier string 22 positioned in a wellbore 24 extending from a surface location 26 . In some applications, the wellbore 24 is cased with a well casing 28 . The perforating gun carrier string 22 comprises a perforating gun 30 having a perforating gun carrier assembly 32 . The perforating gun carrier assembly 32 comprises a perforating gun carrier 34 , e.g. a perforating gun carrier tube, designed to hold a plurality of charges 36 . Depending on the specific application, the charges 36 may comprise shaped charges constructed and oriented to form precise perforations that extend radially outward through the casing 28 and into a surrounding formation 38 . In the example illustrated, the perforating gun carrier assembly 32 also comprises a pressure enhancement mechanism 40 which may be carried by perforating gun carrier string 22 at a location within the perforating gun carrier 34 and/or at a position external to perforating gun carrier 34 . It should be noted that in well related applications, wellbore 24 may comprise many types of wellbores, including deviated, e.g. horizontal, single bore, multilateral, cased, and uncased (open bore) wellbores.
Referring generally to FIG. 2 , an embodiment of a perforating gun carrier 34 is illustrated. In this embodiment, perforating gun carrier 34 comprises an interior 42 separated from an exterior environment, e.g. a wellbore environment, by a gun carrier wall 44 . In at least some applications, the carrier wall 44 is arranged in a tubular form with charges 36 mounted to orient the perforations in a radially outward direction. The pressure enhancement mechanism 40 is mounted to enable a controlled increase in pressurization of interior 42 , as indicated by arrows 46 . The increase in pressurization of interior 42 is selectively controlled to counter or to eliminate the differential in pressure between the internal pressure 46 and an external pressure represented by arrows 48 .
For example, pressure enhancement mechanism 40 may be designed to enable selective release of gas into interior 42 to provide control over the pressure differential, e.g. to provide a reduction of the pressure differential between internal pressure 46 and external pressure 48 . In a variety of well applications, the internal pressure represented by arrows 46 can be increased while the perforating gun carrier 34 is in wellbore 24 . By way of example, the internal pressure may be increased gradually and continuously as the perforating gun carrier 34 is deployed downhole along wellbore 24 . In another example, the internal pressure may be increased periodically in discrete steps during conveyance of perforating gun carrier 34 downhole. The amount of pressure increase may be determined based on the collapse resistance of the perforating gun carrier 34 and/or based on other application related parameters.
Referring again to FIG. 2 , the illustrated example of a pressure enhancement mechanism 40 comprises a chamber 50 containing a pressurized gas 52 . The chamber 50 may be placed in operative cooperation with interior 42 of perforating gun carrier 34 to selectively release the high pressure gas 52 into interior 42 to decrease or eliminate the differential pressure acting on perforating gun carrier 34 . The chamber 50 may be carried by perforating gun string 22 and may be placed proximate, e.g. adjacent, the perforating gun carrier 34 . In this example, the pressure enhancement mechanism 40 also comprises a gas release member 54 which may be selectively activated to provide a controlled release of pressurized gas 52 from chamber 50 and into interior 42 of perforating gun carrier 34 . By way of example, the gas release member 54 comprises a valve or other actuatable member which may be actuated, for example, electrically or hydraulically via input from a control line 56 . However, the gas release member 54 may comprise other types of mechanisms, such as passive release mechanisms in the form of spring-loaded members and/or a series of rupture discs. In other embodiments, the gas release member 54 may comprise a timed release mechanism, a pressure activated mechanism, or another suitable gas release mechanism to provide for controlled increase of pressure within interior 42 .
In another example, the pressure enhancement mechanism 40 comprises a gas generator 58 , as illustrated in FIG. 3 . The gas generator 58 may be selectively activated to release gas into interior 42 and to thus raise the internal pressure, thereby reducing the pressure differential between the internally acting pressure 46 and the externally acting pressure 48 . In some applications, the gas generator 58 may be located at an internal location within perforating gun carrier 34 . By way of example, the gas generator 58 may comprise a propellant charge which is selectively activated to release gas and to increase the pressure within interior 42 . In another example, the gas generator 58 may comprise a subcritical fluid, e.g. CO2, which is activated at downhole temperature. Depending on the specific type of gas generator 58 , a corresponding gas release member 54 may be used to selectively initiate activation of the gas generator 58 for release of the gas within interior 42 .
Referring generally to FIG. 4 , an illustration is provided of the perforating gun carrier 34 following detonation of charges 36 to form a plurality of perforations 60 . As illustrated, the perforations 60 may be formed in a radially outward direction through casing 28 and into the surrounding formation 38 . By increasing the pressure within interior 42 as the perforating gun carrier 34 is moved downhole, the collapse tendency of the perforating gun carrier 34 is reduced and the potential for a detrimental post-shot pressure pulse is reduced or eliminated. The amount of pressure increase may be determined according to collapse resistance, leak resistance, and/or susceptibility to damage from the post-shot pressure pulse. Depending on the parameters of a specific application and environment, the internal pressure, represented by arrows 46 in FIGS. 2 and 3 , may be sufficiently increased to reduce an underbalance pressure situation; to equalize internal and external pressures; or to create an overbalance pressure situation in which the internal pressure is greater than the external pressure.
Internal perforating gun carrier post-shot pressures also are affected by the explosive detonation gas density and temperature resulting from detonation of charges 36 . The addition of gas 52 and the resulting increase of internal pressure via activation of pressure enhancement mechanism 40 further increase the post-shot gas density and thus further increase the post-shot pressure acting against the influx of well fluid (see arrows 62 ) and against the resultant detrimental pressure pulse. In FIG. 4 , a pressure pulse is illustrated by arrows 64 as propagating away from perforating gun carrier 34 . Similarly, a corresponding decompression wave is illustrated by arrows 66 . The introduction of additional gas 52 and higher internal pressures via pressure enhancement mechanism 40 enables better control over or even elimination of these effects caused by detonation of charges 36 .
In operation, the pressure level in interior 42 of perforating gun carrier 34 (and thus the pressure differential acting on the perforating gun carrier 34 ) may be selectively controlled during conveyance of the perforating gun 30 downhole or to another desired perforating region. As illustrated in FIGS. 5-7 , a controlled increase in pressure within perforating gun carrier 34 is provided during conveyance of the perforating gun carrier 34 downhole into wellbore 24 via perforating gun string 22 . Referring to FIG. 5 , the pressure enhancement mechanism 40 may be initially activated once the perforating gun carrier 44 is moved down to a desired position within wellbore 24 , as indicated by arrow 68 .
During conveyance to greater depths downhole, additional gas 52 is released to increase the pressure within perforating gun carrier 34 , as illustrated in FIG. 6 . As discussed above, the release of gas may be conducted continually or periodically at discrete locations as the perforating gun carrier 34 is lowered downhole. The increased internal pressure within interior 42 reduces the pressure differential acting on perforating gun carrier 34 , thus enhancing collapse survivability while also inhibiting leaks into the perforating gun carrier 34 .
Once the perforating gun 30 is at a desired perforating region along formation 38 and once the internal pressure created via pressure enhancement mechanism 40 is at a desired level, the charges 36 are detonated to create perforations 60 as illustrated in FIG. 7 . When the perforating gun 30 is fired, in-gun pressure is increased above what it otherwise would be due to the post-detonation gas pressure created by the explosion/heat of the detonated charges 36 . This increase in pressure plus the pre-shot static pressure established by the controlled release of gas 52 via pressure enhancement mechanism 40 eliminates or minimizes the severity of perforating gun filling and thus eliminates or minimizes the magnitude of the resultant pressure pulse.
The system and methodology described herein may be employed in non-well related perforation applications which subject the perforating gun to pressure differentials. The type of perforating gun and charges employed may vary depending on the specific application and environment in which the perforating application is carried out. In some applications, the explosive charges 36 can be replaced with other types of perforating devices or techniques, such as high pressure jet perforating tools.
Additionally, the system and methodology may be employed in many types of well applications, including many types of single zone or multi-zone perforating applications. Single gas generating devices or a plurality of gas generating devices may be used in cooperation with each perforating gun carrier. Additionally, the size and construction of the perforating gun carrier can vary depending on the specific parameters of a given application and/or environment. Furthermore, the perforating gun may be combined with several types of additional devices and systems to carry out other functions at the perforating region. For example, a variety of chemical treatment devices or other well treatment related devices may be combined with the perforating string to carry out desired service operations in the well environment or in another perforating environment.
Although only a few embodiments of the system and methodology have been described in detail above, those of ordinary skill in the art will readily appreciate that many modifications are possible without materially departing from the teachings of this disclosure. Accordingly, such modifications are intended to be included within the scope of this disclosure as defined in the claims. | A technique facilitates a perforation operation. A perforating gun carrier is combined with a pressure enhancement mechanism. The pressure enhancement mechanism provides a controlled increase in pressure within the perforating gun carrier as the perforating gun carrier is delivered into a higher pressure environment. The increase in internal pressure counters the buildup of a pressure differential to the degree desired for a given perforating gun carrier. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to piping hangers for wells and specifically to seals for piping hangers.
2. Brief Description of the Background Art
U.S. Pat. Nos. 4,109,942 and 4,056,272, both issued to Morrill, disclose tubing hangers with seal arrangements designed to contain downhole well pressures. These patents disclose metal-to-metal seals with a frustoconical metal gasket between the tubing hanger and the wellhead and an "x" cross sectional resilient metal gasket between the hanger and the christmas tree.
While the design illustrated in these patents has many advantages, due to tolerance problems arising in part from the frustoconical arrangement of the sealing surfaces, a less than ideal seal is achieved. Moreover, the arrangement illustrated requires a relatively large number of seal members.
SUMMARY OF THE INVENTION
It is the primary object of the present invention to provide a piping suspender in which a metal-to-metal seal is achieved between a piping hanger and a well head which minimizes the number of seal members required and which provides an accurately controllable metal-to-metal seal.
These and other objects of the present invention are achieved by a piping suspender with a well head having an axial bore, and a piping hanger. The hanger is mountable within the well head bore. The hanger and the well head each include a shoulder oriented generally transversely with respect to the length of the bore. The shoulders are arranged in opposition to sealingly abut with one another. A seal member is positioned between the piping hanger and the well head adjacent the shoulders.
In accordance with another embodiment of the present invention, a piping suspender includes a well head having an upper surface and a piping head adapter releasably connectable to the upper surface of the well head. A piping hanger bore extends through the piping head adapter and well head. The bore includes a reduced diameter section in the head adapter spaced from the well head and an enlarged diameter section in the well head adjacent the piping head adapter. The well head includes a generally horizontally disposed land defined by the end of the enlarged diameter section. A piping hanger, mountable within the bore, includes an annular extension sized to be received within the enlarged diameter section. The annular extension has upwardly and downwardly facing, generally horizontally oriented shoulders. The upwardly facing shoulder is arranged in sealing abutment with the head adapter and the downwardly facing shoulder is arranged in sealing abutment with the land. A pair of annular seal passages are provided, one positioned between the hanger and the head adapter and the other positioned between the hanger and the well head. A pair of annular seals are positioned one in each seal passage.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a partial, partially sectioned front elevational view of one embodiment of the present invention; and
FIG. 2 is an enlarged cross-sectonal view of a portion of the embodiment shown in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawing wherein like reference characters are used for like parts throughout the several views, a piping suspender 10, shown in FIG. 1, includes a head adapter 12, a well head 14, and a piping hanger 16. The term "adapter", as used herein, can include a connector for connecting the Christmas tree (not shown) to the well head 14 or the Christmas tree itself. The term "piping" as used herein may include tubing or casing. The head adapter 12 and head 14 may include flanges 18 connectable by bolts 20 to sealingly abut the upper face 22 of the head 14 against the face 24 of the head adapter 12. The adapter 12 and head 14 have an axial bore 26 which defines a central opening 28 capable of receiving the piping hanger 16.
The head 14 includes a counterbore 30 which receives an annular extension or flange 32 of the piping hanger 16. The interior of the pipe hanger 16 also includes a bore 34 with a threaded end 36 to enable the hanger 16 to connect to a conventional well tubing string 17. The adapter 12 may include a counterbore 31 to receive and contain the upper extension 33 of the hanger 16. The diameter of the counterbore 30 is advantageously greater than the diameter of the counterbore 31, so that a portion of the face 24 forms the overhang or shoulder 35.
The hanger 16 is positioned within the counterbore 30 by the lockscrews 38 which thread through the head 14 and are adjustable by the spindle 40 positioned on the exterior of the head 14. The beveled ends 42 of the lockscrews 38 mate with the lower edges 44 of countersinks 46 formed in the lateral side 48 of the annular extension 32. The juxtaposition of a beveled end 42 and lower edge 44 provides a wedging action to downwardly displace the piping hanger 16 upon insertion of the lockscrew 38.
The axial length of the counterbore 30 corresponds precisely to the length of the annular flange 32 so that when the piping hanger 16 is positioned in sealing arrangement within the bore 26, the face 24 of the adapter 12 is flush against the face 22 of the head 14. Moreover the generally transversely arranged upper shoulder 50 of the extension 32 may be abutted flush against the face 24 while the generally transversely arranged lower shoulder 52 of the extension 32 is positioned flush upon the annular land 54 defined in the head 14 by the counterbore 30.
The annular extension 32 has recesses 58 located just radially inwardly of the lateral side 48 and each shoulder 50 or 52, and in line with the adjacent outer surface 56 or 57 of the pipe hanger 16. The recesses 58 each include a generally transversely oriented end wall 60, an axially oriented inner wall 62 and a countersunk outer wall 64, as shown in FIG. 2. The recesses 66a and 66b, the mirror images of the recesses 58, are formed adjacent each recess 58. The combinations of the opposed recesses 58 and 66 create the seal passages 68a and 68b which receive the annular seals 70a and 70b. The annular seals 70, in the illustrated embodiment, viewed cross-sectionally, have tapered, radially outwardly directed sealing faces 74.
Adjacent to each shoulder 50 or 52, is a chamfered surface 76 which forms a wall of each seal passage 68. In the case of the upper shoulder 50, the associated chamfered surface 76a tapers upwardly and inwardly away from the shoulder 50. In the case of the lower shoulder 52, a chamfered surface 76b tapers inwardly and downwardly from the shoulder 52. The chamfered surfaces 76, together with the horizontal walls 77 and inner walls 62, create the remainder of each seal passage 68 that conforms generally to and receives an annular seal 70. In addition, an indentation 78 is formed adjacent the base of the chamfered surface 76b. This allows for the inclusion of a bowl protector (not shown) which may be positioned over the seal surfaces including the land 54 and the chamfered surface 76b, to protect those surfaces when well tools are inserted and withdrawn from the well, with the piping hanger 16 removed.
While the annular seals 70 may take a variety of forms, they are generally made of a ring of relatively soft metal whose diameter is slightly greater than the diameter of the seal passages 68 so that the sealing face 74 is pressed against the outer walls 64 and chamfered surfaces 76 of the sealing passages 68. A variety of metal, pressure energized seal rings, such as the commercial "R-CON", or "Graloc" seals may be utilized as the seals 70. Conveniently the seals 70 are retained within the seal passages 68 by the retainer ring 81, which fits into an aperture 80 in the tubing hanger 16. Because of the initially greater diameter of the seals 70 with respect to the seal passages 68, a passageway 82 is defined along the non-sealing walls 60, 62, and 77.
To provide an adequate seal between the faces 22 and 24, a seal ring 84 is located in a groove 85 in each of the faces 22 and 24 at a position intermediately between the outside of the head 14 and the hanger 16. The seal 84 may take a variety of forms, including that of a conventional BX seal. Similarly, the seals 86 are located between the upper extension 33 of the piping hanger 16 and the adapter 12, above the seal 70a. The seals 86 advantageously take the form of T-seals with their prongs 88 extending from the pipe hanger 16 towards abutment with the bore 26 of the adapter 12. While two seals 86 are shown in the illustrated embodiment, one or more such seals are normally adequate for the present purposes. In similar fashion at least one seal 90 is located below the seal 70b, between the piping hanger 16 and the head 14. The seal 90 may be a T-seal as illustrated or an O-ring with back up rings.
A plurality of seal test lines 92, 94 and 96 extend to the exterior of the head 14 and adapter 12. The line 92 extends from a point adjacent the juncture of the hanger 16 and adapter 12, below the seals 86, to an external connector 98. The line 94 extends from the joint between the head 14 and adapter 12 and in between the hanger 16 and seal 84 to an external connector 98. Finally, the test line 96 extends from a point below the lower annular seal 70b and above the seal 90, to an external connector 98. When no tests are being run, each of the connectors 98 may be closed to prevent leakage. A source of pressure or vacuum may be connected to each of the connectors 98 in order to test the functioning of the seals 70, 84, 86, and 90.
The operation of the suspender 10 may be generally along the following lines. Initially, with the adapter 12 disconnected from the head 14, the piping hanger 16 with the string 17 connected, is positioned within the bore 26 of the head 14. This is done with the lockscrews 38 withdrawn from the counterbore 30 so that the annular extension 32 is positioned with its lower edge 52 spaced slightly from the land 54. This spacing is due to the presence of the adjacent annular seal 70b which presses against the outer wall 64 of the recess 58 and the chamfered surface 76. Often the weight of the tubing string 17 is sufficient to cause the lower shoulder 52 to meet and abut sealingly against the land 54 such that the annular seal 70b seals against the adjacent faces of the extension 32 and chamfered surface 76. If this is not the case, the lockscrews 38 are adjusted inwardly to wedge the piping hanger 16 downwardly until the malleable annular seal 70b is compressed sufficiently to provide metal-to-metal sealing contact between the shoulder 52 and the land 54.
With the seal 84 in position in the grooves 85, the adapter 12 is bolted by way of bolts 20 and flanges 18 onto the head 14 so that the seal 84 provides a good seal between the abutting faces 22 and 24. The bolts 20 are tightened until a good metal-to-metal seal is achieved between both the faces 22 and 24 and the shoulder 50 of the extension 32 and the face 24 of the adapter 12. At the same time the upper seal 70b is also sealingly pressed against the chamfered surface 76 and outer wall 64 to create a pressure energized seal at the juncture.
The use of generally transversely arranged, opposed sealing surfaces 50 and 35, and 52 and 54 enables an extremely effective seal to be achieved in part because the square shoulders permit closer tolerancing than conventional frustoconical sealing surfaces.
The lower seal 70b and the seal 90 may be tested, before the blowout preventers (not shown) are removed, by pressurizing the line 96 to a level above working pressure, conveniently 1000 psi above working pressure. The pressure energizes the seals 70b and 90, as described previously, and enables the operation of the seals to be tested and if necessary corrected before the blowout preventers are removed. After the head adapter 12 is installed, the upper annular seal 70b and the seal 86 are tested by pressurizing the upper seal test line 92 to working pressure plus 1000 psi while leaving the line 94 open. With the lines 92 and 96 at 1000 psi above working pressure, the test line 94 is then pressurized to working pressure to test the seal 84. Finally the pressure is diminished in lines 94, 96, and 92, in that order.
While the present invention has been described with respect to a single preferred embodiment, those skilled in the art will appreciate a number of variations and modifications and it is intended within the appended claims to cover all such variations and modifications as come within the true spirit and scope of the present invention. | A piping suspender with a metal-to-metal seal includes a piping hanger with an annular extension received in a counterbore of a well head and confined by a head adapter. The extension includes upwardly and downwardly facing, generally horizontally disposed shoulders. The upwardly facing shoulder abuts with the lower face of the head adapter and the downwardly facing shoulder abuts with an annular, generally horizontally disposed shoulder on the well head, to sealingly support the piping hanger and connected piping on the well head and to seal the hanger with respect to the adapter. A set of test lines are provided to enable seal testing. | 4 |
BACKGROUND OF THE INVENTION
This invention is related to the recovery of oil from a hydrocarbon-bearing subterranean formation by injection of a water-soluble polymer in an aqueous solution into the oil reservoir to stimulate additional production and recovery of hydrocarbons. More specifically, the polymer employed is a modified heteropolysaccharide produced by the bacterium Xanthobacter sp.
Generally, oil or hydrocarbons are recovered from subterranean formations BY initially employing primary recovery techniques. Once primary production is no longer economically feasible, some form of enhanced recovery is applied to these formations to abstract further quantities of oil. One of the earliest and most popular forms of enhanced oil recovery is water injection in which water or brine is injected into the hydrocarbon containing formation to force the residual hydrocarbons contained therein through the formation to a production well which is placed at an appropriate location. Since the viscosity of the hydrocarbons present in the hydrocarbon bearing formation is usually higher than the viscosity of water or other fluids injected into the formation, the quantity of hydrocarbons removed by such methods is small and further, frequently results in the bypassing of a substantial portion of the hydrocarbons by the less viscous water. This effect is referred to as viscous fingering. This situation is further aggravated by the presence of zones of high permeabilityat various levels in the hydrocarbon bearing formation. These so-called "thief" zones also permit the escape of a substantial portion of the relatively low viscosity water or brine without any displacement of hydrocarbons.
Other problems have arisen in the use of water-soluble bacterial polysaccharides for enhanced oil recovery since the viscous injection fluid (2-2000 cps) is often a diluted fermentation broth (0.01-1.0% w/v) which may contain residual cell bodies, digested solid nutrients and polymer aggregates (microgels). For most polysaccharides, aggregation is exacerbated by the elevated concentrations of mono-, di- and trivalent cations found in reservoir brines which may form specific ionic complexes between polymer chains and/or may generally reduce the "solvent power" of the aqueous media allowing the polymer to readily self-associate. The operational result of aggregation is to reduce the injection rate and increase the injection pressure required to introduce the polymer solution into the subterranean oil reservoir. Further, in some extreme cases, polymer molecules aggregated into networks may cause plugging in the porous reservoir rock matrix which could ultimately result in permanent damage to the formation. In the present invention, the ability to inject a heteropolysaccharide into a hydrocarbon-containing reservoir is significantly improved by including the compound beta-fluoropyruvate in the fermentation medium of the organism Xanthobacter sp. This effect is especially pronounced at elevated salinity.
Thus, it is an object of the present invention to provide an improved process for recovering hydrocarbons from subterranean hydrocarbon bearing formation.
Also, it is an object of the present invention to provide an improved additive, i.e., drive fluid, for enhancing the recovery of such hydrocarbons.
DISCLOSURE STATEMENT
U.S. Pat. Nos. 2,827,964 and 3,039,529 disclose a method of improving the efficiency of enhanced recovery techniques through the addition of a substance to the water or brine to increase its viscosity and describe the use of high molecular weight, partially hydrolyzed polyacrylamides as thickening agents for aqueous fluids employed in enhanced oil recovery systems.
U.S. Pat. No. 3,581,824 describes the use of a heteropolysaccharide produced by bacterial fermentation of carbohydrates for the same purpose as that of U.S. Pat. Nos. 2,827,964 and 3,039,529.
U.S. Pat. No. 4,548,268 discloses a process for recovering hydrocarbons from a subterranean hydrocarbon bearing formation penetrated by an injection well and a production well and includes the steps of injecting into the formation via an injection well an aqueous drive fluid comprising water and more than about 200 parts per million of Beta-(1-6)-D-glucan having an average molecular weight of more than about 2×10 4 .
The process also includes using a concentrate of the glucan in dimethylsulfoxide or in a four molar or higher concentration of aqueous urea which is diluted to form the aqueous drive fluid.
SUMMARY OF THE INVENTION
This invention discloses a new, novel heteropolysaccharide polymer produced by Xanthobacter sp. (Strain NW11, ATCC# 53272) after modification of the polymer by the addition of beta-fluoropyruvate to the fermentation medium. This modification improves the filterability of the polymer and, thus, potential reservoir injections to a point where high levels of salt can be tolerated.
DETAILED DESCRIPTION OF THE INVENTION
NW11 was isolated from a sample from a waste-water pond in Fountainhead, Okla. It is a gram negative, non-sporeforming, non-motile short rod which forms yellow, mucoid colonies. It was identified as Xanthobacter sp. by the American Type Culture Collection in Rockville, Md.
The heteropolysaccharide is produced in 500 ml flasks at 30° C. after 5-7 days of rotary shaking at 200 rpm. The medium (100 mls) contains 1.75 g glucose, 0.5 g K1HP04, 0.02 g MgSO4 and either 1.4 g Corn Steep Liquor or 0.3 g Bacto-Peptone. Good growth and polymer production by the organism is obtained using either source (Table I). Tryptone and enzyme hydrolyzed casein can also be used.
TABLE I______________________________________GROWTH AND POLYMER PRODUCTION BY NW11 BrothMedium Viscosity (cps) % Solids*______________________________________Corn Steep Liquor 3000 1.04Bacto-Peptone 3600 0.95______________________________________ *Amount of polymer as measured by isopropanolprecipitable material
When beta-fluoropyruvate (BFPyr) was used, it was added to the medium in a sterile, concentrated aqueous solution. Growth of the organism is inhibited by BFPyr so this was minimized by adding it after 6-12 hours.
The polymer from NW11 contains the sugar glucose, glucuronic acid and mannose in a 2-1-1 ratio. It also contains acetate at a level of less than one per 4 sugar repeat unit.
After the fermentation the broth is adjusted to pH=7.0 and autoclaved for 20 minutes in a stoppered tube. This results in maximum viscosity. Autoclaving does not have an affect on the filterability.
In an oil recovery process, it is important to determine the ability to inject a polymer containing aqueous drive fluid into a subterranean hydrocarbon bearing formation through an injection well without excessive pressure buildup due to pore plugging. Drive fluids formed from many polymers such as xanthum gum may contain microgels, as well as residual dead bacterial cell bodies. Such materials often give rise to poor injectability due to the plugging of the area near the well bore.
Injectivity of polymer solutions into formations can be correlated with a simple laboratory filterability test. In this test, a dilute solution (viscosity about 20 cps) of the polymer is passed through a Nucleopore membrane of 47 mm diameter and 3.0 u pore size. Pressure is held at 20 psi and the flow rate is monitored. The time necessary to accumulate a given volume of filtrate is measured and a filter factor (FF) is calculated according to the following formula. ##EQU1##
Values greater than about 2 indicate filter plugging and are unacceptable. Samples for which 300 mls of filtrate cannot be collected after about 600 seconds are also considered unacceptable.
Often a polymer will have acceptable filterability in water or low salt levels but upon increasing the salt the filter factor will rise above 2 and be said to fail. The maximum salt concentration at which the filterability is acceptable is called the critical salinity (C*) and is measured in units of percent NaCl.
The present invention and the advantages provided by such will be more apparent by the examples provided below.
EXAMPLE 1
NW11 was grown in peptone medium and the broth was diluted to a viscosity of about 20 cps. The filterability was tested in water, 2 percent and 4 percent NaCl. The results (Table II) show that the polymer passes the filterability test in H 2 O, is marginally acceptable in 2 percent NaCl (the filter factor is very close to 2) and is unacceptable in 4 percent NaCl. The C* of this sample is 2. For the 4 percent NaCl filtrate, less than 300 mls were collected in 600 seconds. The filter factor generally increases very rapidly when C* is exceeded.
TABLE II______________________________________FILTERABILITY OF NW11 IN PEPTONE MEDIUMSolution Filter Factor______________________________________H.sub.2 O 1.22% NaCl 2.34% NaCl >10______________________________________
EXAMPLE II
Three flasks of NW11 were grown in peptone medium. One flask remained unmodified as the control. BFPyr at levels of 0.2 mM and 0.6 mM were added to the other two flasks just before inoculation of the organism. After 7 days of growth, the broths of each flask were diluted to 20 cps and the filterability tested. The results are shown in Table III. C* in the 0.2 mM flask was raised from 2 to 4 and with the higher BFPyr flask to 6.
TABLE III______________________________________FILTERABILITY OF BFPyr MODIFIED NW11Filter FactorSample H2O 2% NaCl 4% NaCl 6% NaCl 8% NaCl______________________________________Control 1.18 1.34 >10 -- --0.2 mM 1.09 1.55 2.04 >10 --BFPyr0.6 mM 1.38 1.51 1.60 1.67 >10BFPyr______________________________________
EXAMPLE III
Two flasks of NW11 were grown in peptone medium. One flask remained unmodified as the control. BFPyr at a level of 0.6 mM was added to the other flask just before inoculation of the organism. After 7 days of growth, the broths of each flask were diluted to 20 cps and the filterability tested. The C* of the control flask was 2 and the BFPyr-treated flask was 6. The polysaccharide was purified from the cells. The acetate levels were determined by a KOH hydrolysis followed by HPLC analysis. NW11 polymer from the control flask had a level of 5.7 percent and the BFPyr flask was 7.8 percent. This indicates that the improvement of filterability may be due to an increase in the acetate level of the polymer.
EXAMPLE IV
Four flasks of NW11 were prepared in peptone medium. One flask remained unmodified as the control. To the other three, 0.6 mM BFPyr was added either before inoculation, after 7 hours of growth, or after 12 hours of growth. Growth in the flask (as measured by absorbance) in which the BFPyr was added at time 0 was greatly inhibited, the flask with the 7 hour addition less so and the 12 hour flask was only inhibited slightly (Table IV). The amount of polymer production at the end of 7 days, as measured by percent isopropanol precipitable material, was only slightly reduced as compared to the control and not much different from each other.
TABLE IV______________________________________EFFECT OF BFPYR ON GROWTH AND POLYMERPRODUCTION OF NW11 OD 600 OD 600Sample at 24 hrs at 48 hrs % Solids______________________________________Control 3.10 7.03 0.830.6 mM BFPyradded at0 hours 0.22 0.82 0.577 hours 0.64 2.11 0.6112 hours 2.25 6.93 0.65______________________________________
EXAMPLE V
Six flasks of NW11 were prepared in peptone medium. One flask remained unmodified as the control. To the other five, varying amounts of BFPyr from 0.6 to 3.0 mM were added after 7 hours of growth. The higher the amount of BFPyr, the more polymer production was inhibited, as measured by broth viscosity and percent solids (Table V). Filterabilities of each flask in increasing salt concentrations were performed. The C* increased from 0 in the control to 9 percent NaCl at 1.8 mM but did not increase at higher levels of BFPyr. This indicates that 1.8 mM BFPyr is optimum for increase in C* with minimum inhibition of growth.
TABLE VI______________________________________EFFECT OF BFPYR CONCENTRATION ON NW11Sample Broth C*After 7 days Viscosity (cps) % Solids % NaCl______________________________________Control 1900 0.65 0BFPyr0.6 mM 1700 0.64 51.2 mM 1400 0.57 71.8 mM 1000 0.49 92.4 mM 900 0.46 93.0 mM 800 0.40 9______________________________________
EXAMPLE VI
Samples of NW11 broth usually contain extracellular protein as well as polysaccharide. Three flasks of NW11 grown for 7 days in peptone medium were prepared. Three flasks of NW11 in which 1.8 BFPyr was added after 7 hours were also prepared. Each batch of 3 flasks was combined, autoclaved and purified polysaccharide prepared. This was accomplished by diluting the sample 10 fold, ultracentrifuging for 2 hours at 50,000 xg, precipitating 3-4 times with isopropanol and dialyzing extensively against water. This series of steps was carried out 2-3 times. Final samples containing less than 0.5 percent protein were obtained for the NW11 control sample and less than 2 percent protein for the BFPyr modified sample. Solutions of about 20 cps were made up for both and filterabilities performed. The NW11 control had a C* of 0 percent NaCl and the BFPyr-modified sample had a C* of 6 percent NaCl. Therefore the improvement in filterability for NW11 by BFPyr is due to an effect on the polysaccharide and not the extracellular protein.
It is pointed out that the scope of the present invention is determined by the following claims and is not to be considered part of the prior art. | A process for recovering hydrocarbons from a subterranean hydrocarbon bearing formation penetrated by an injection well and a production well which comprises injecting an aqueous drive fluid into the formation and forcing the drive fluid through the formation to recover the hydrocarbons from the production well. | 8 |
TECHNICAL FIELD
[0001] The present invention pertains to the field of mechanical manufacturing technologies, relates to a device for triggering a steel rope brake used in an elevator, and more particularly, to a power-loss triggering device.
BACKGROUND
[0002] At present, a power-on triggering manner is used for triggering a latch hook of a steel rope brake used in an elevator. However, the power-on triggering control manner has a disadvantage that a triggering device is unable to trigger a switch (latch hook) mechanism of a brake in case that external power is lost, a back up supply is insufficient, or a circuit or device goes wrong, and thus it has a high safety risk degree. Specifically speaking, a power-on triggering manner has long safety chains along vertical and horizontal directions. In the vertical direction, a safety chain formed by a power supply, a control logic unit, an electromagnet, a back-up power supply and a triggering device. In the horizontal direction, in a power-on triggering process, failure detecting and monitoring links are more, and it is relatively difficult to implement failure-free monitoring feedback, where a brake is unable to pick up as long as one link goes wrong because this may cause a fatal risk that a switch (locking) mechanism is failed in turning on; meanwhile, the power-on triggering is larger in sustained current, and larger in capacity required for a back-up power supply, slow in system response, and high in power consumption.
SUMMARY
[0003] In order to overcome the disadvantage of the prior art, the present invention provides a power-loss triggering device, which has a larger action force to turn on a switch (locking) mechanism under a premise of obtaining a larger stroke with a smaller electromagnetic force, thereby solving the problem of turning on the switch (locking) mechanism under a power-loss state.
[0004] The present invention is implemented by means of the following technical solution: a power-loss triggering device, including: a frame, an electromagnet and an impact bar; the impact bar vertically and movably penetrates through the frame, an upper end and a lower end of the impact bar are respectively located outside the frame, an upper section of the impact bar is provided with a limiting buffer cushion, and a lower end is an impact end; the electromagnet is installed on the frame; an energy storage piece is arranged and the energy storage piece may exert a downward action force on the impact bar; when the electromagnet is energized, the impact bar is positioned through electromagnetic force; when the electromagnet loses power, the impact bar loses a holding power from the electromagnet and conducts a downward impact movement under the action force of the energy storage piece.
[0005] Preferably, the frame is shaped like a square frame body, and a rear side face of the frame is fixedly connected with a rear plate.
[0006] Preferably, an upper edge and a lower edge of a front face of the frame are each provided with a pin hole for installing a pin, and a cover plate is fixedly mounted on the side face through the pins.
[0007] Preferably, a housing of the electromagnet is fixedly mounted on the frame. Preferably, the lower end of the impact bar is provided with an impact bolt, and an upward side of the impact bolt is provided with a buffer cushion or a check ring.
[0008] Preferably, the energy storage piece is a spring; a lower section of the impact bolt is externally sleeved with the spring, and upper and lower end faces of the spring are respectively propped to a lower surface of the frame, the buffer cushion or the check ring.
[0009] Preferably, the spring is externally sleeved with a spring pocket, a lower end of the spring pocket is disposed on the buffer cushion or the check ring, and a height of the spring pocket is smaller than a length of the spring under a normal state.
[0010] Preferably, the upper end of the impact bar is fixedly connected with a pull ring.
[0011] Preferably, the upper end of the impact bar forms a pull ring hole, and the impact bar is fixedly connected with the manual pull ring through the pull ring hole.
[0012] Preferably, two sides of the frame are respectively provided with the electromagnet, and the two electromagnets are symmetrically mounted at the two sides of the frame.
[0013] Preferably, the impact bar forms two downward inclined planes arranged in the frame, an upper part and a lower part of the inclined planes of the impact bar respectively are a guide surface and an electromagnetic pull-in surface, a width of the electromagnetic pull-in surface is smaller than that of the guide surface; an electromagnetic shaft of the electromagnet movably penetrates through the frame, and an inner end face faces the electromagnetic pull-in surface at a same side of the impact bar, this end of the electromagnetic shaft forms an inclined plane, and the inclined plane of the electromagnetic shaft fits with an inclined plane at the same side of the impact bar; when the electromagnet is energized, horizontal electromagnetic force is generated by forming a magnetic circuit by an end face of the electromagnetic shaft and the electromagnetic pull-in surface of the impact bar, and the impact bar is locked by the electromagnetic shaft propping against corresponding inclined planes at two sides of the impact bar.
[0014] Preferably, the electromagnetic shaft forms an upward stepped surface which transits to the inner end face of the electromagnetic shaft by means of the inclined plane of the electromagnetic shaft.
[0015] Preferably, the electromagnetic shaft movably penetrates through a winding frame, two ends thereof penetrate through the winding frame enwound by a coil, and the winding frame is mounted inside the housing of the electromagnet.
[0016] Preferably, an inner end of the electromagnetic shaft is provided with a flux-insulation limit ring which is arranged at one side of the stepped surface, an inward side face of the flux-insulation limit ring is provided with a retainer ring externally sleeved on the electromagnetic shaft; an outward side face of the flux-insulation limit ring is opposite to one side face of the winding frame, and after moving together with the electromagnetic shaft, the flux-insulation limit ring may attach to or break away from a corresponding side face of the winding frame.
[0017] Preferably, an upper side and a lower side of the frame each is provided with a hole, and a shape of the hole fits with that of a corresponding section of the impact bar.
[0018] Preferably, the impact bar is provided with a wedge block positioned in the frame, two sides of the wedge block respectively form a downward inclined plane; a bottom edge of the frame is provided with two oscillating support rods, an upper part of the support rod forms an inclined plane of the support rod which fits with the inclined plane at the same side of the wedge block; the inner end of the electromagnetic shaft of the electromagnet rotates and fits with the upper side of the support rod; under an action of the electromagnetic shaft, the support rod maintains a vertical state, and the impact bar is locked by the inclined plane of the support rod coming into contact with the inclined plane of the wedge block.
[0019] Preferably, the upper part of the support rod forms a support rod groove; the inner end of the electromagnetic shaft forms a groove notch which is movably sandwiched between two sides of the support rod, and the groove notch is provided with a support rod pin which is rotatably placed into the support rod groove.
[0020] Preferably, the support rod is mounted on the bottom edge of the frame by means of a rotating shaft of the support rod.
[0021] Preferably, the rotating shaft of the support rod is provided with two spacer bushes disposed at two sides of the support rod to relatively fix the support rod to a middle position.
[0022] Preferably, the housing of the electromagnet is fixedly mounted in the frame by means of a mounting plate.
[0023] Preferably, the housing of the electromagnet is internally provided with a coil former, and the electromagnetic shaft movably penetrates through the coil former and the mounting plate.
[0024] Preferably, an external port of the housing of the electromagnet fixes an end cover.
[0025] Preferably, the housing of the electromagnet is internally provided with a pull-in disk, a first side face of the pull-in disk faces an inner side face of the end cover; and a second side face of the pull-in disk faces one end of the electromagnetic shaft.
[0026] Preferably, the second side face of the housing of the electromagnet forms a raised conical surface, and a corresponding end part of the electromagnetic shaft forms a taper hole which fits with the conical surface of the pull-in disk.
[0027] It is found through document retrieval of the prior art, all existing steel rope brake triggering mechanisms adopt the power-on triggering manner. In terms of reducing safety control risk, a power-loss triggering safety is better. It is relatively easy to implement power-loss triggering having small stroke and small action force. However, to large stroke and large action force, it cannot be implemented by a high-power electromagnet in a long-term power-up state. The high-power electromagnet brings large current and high calorific capacity, and thus a required back-up power supply is large in capacity, high in power consumption, and easy to cause overheating damage. For this reason, the present invention adopts a manner of direct pull-in of the electromagnet and a manner of the electromagnet and the intermediate mechanism to solve the problem of power-loss triggering in terms of low risk, small electric current, low energy consumption, small size, low cost and long life.
[0028] The manner of direct pull-in of the electromagnet in the present invention mainly adopts two implementation manners: a manner of the electromagnet and the switch (locking) mechanism and a manner of the electromagnet and the energy storage impact mechanism, where in the manner of electromagnet and the switch (locking) mechanism, the switch is directly picked up and locked by means of the electromagnet, and when the electromagnet loses power, the switch is automatically turned on by relying on the action force of a locked object ( FIGS. 1 and 2 ). In the manner of the electromagnet and the energy storage impact mechanism, the electromagnet and the energy storage impact mechanism are incorporated into a whole body. In design, the iron core of the electromagnet and the energy storage impact mechanism are incorporated into a whole body ( FIGS. 3 and 4 ). When the electromagnet loses power, the switch (locking) mechanism is turned on by means of impact of the impact bar.
[0029] To the power-loss triggering, safety chains are short in vertical and horizontal directions as long as a monitoring and executing unit is failure-free and a double redundancy design is used to solve a faulty action. Therefore, the trigger control safety risk and monitor control cost are greatly reduced. A trigger mechanism using the power-loss triggering manner needs to maintain an energy storage state for a long time. It is a key point to solve power-loss triggering by solving the problem of small electric current, low power consumption, small size, and automatic electromagnetic resetting under large stroke and large action force.
[0030] The power-loss triggering device is implemented through the electromagnet and an intermediate mechanism. The electromagnetic force of the electromagnet is reduced through the intermediate amplifying mechanism, so that the electric current, the energy consumption and the cost of the electromagnet are reduced, the service life of the long-time energized electromagnet is prolonged, and automatic resetting of the electromagnet is achieved. Furthermore, the electromagnet, an energy storage impact structure and a reset structure of the power-loss triggering device are simple, and convenient for implementation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] FIG. 1 is a schematic diagram of a principle structure of a triggering manner which is an electromagnet and a switch (locking) mechanism;
[0032] FIG. 2 is a schematic local diagram of a principle structure of a triggering manner which is an electromagnet and a switch (locking) mechanism;
[0033] FIG. 3 is a schematic diagram of a principle structure of a triggering manner which is an electromagnet and an energy storage impact mechanism;
[0034] FIG. 4 is a schematic local diagram of a principle structure of a triggering manner which is an electromagnet and an energy storage impact mechanism;
[0035] FIG. 5 is a structural outline drawing according to Embodiment I;
[0036] FIG. 6 is an exploded view of local structure according to Embodiment I;
[0037] FIG. 7 is a structural outline drawing according to Embodiment II;
[0038] FIG. 8 is a partial structural diagram according to Embodiment II;
[0039] FIG. 9 is a local diagram of an internal structure according to Embodiment II; and
[0040] FIG. 10 is a structural drawing of an electromagnet according to Embodiment II.
[0041] In FIGS. 1-4 : 1 manual pull ring, 2 limiting buffer cushion, 3 impact bar, 4 electromagnet, 5 impact bolt, 6 switch (locking mechanism) , 7 pull-in disk, and 8 energy storage (impact) spring.
[0042] In FIGS. 5-6 : 1 manual pull ring, 2 limiting buffer cushion, 3 impact bar, 4 electromagnet, 5 impact bolt, 8 energy storage (impact) spring, 101 electromagnet housing, 102 frame, 103 lower guide hole, 105 buffer cushion, 108 electromagnetic pull-in surface, 109 pushing inclined plane, 110 guide surface, 111 pull ring hole, 112 coil, 113 electromagnetic shaft, 114 winding frame, 115 flux-insulation limit ring, 116 retainer ring, 117 stepped surface of the electromagnetic shaft, 1171 inclined plane of the electromagnetic shaft, 118 rear plate, 121 pin hole and 122 pin.
[0043] In FIGS. 7-10 : 2 - 1 manual pull ring, 2 - 2 limiting buffer cushion, 2 - 3 impact bar, 2 - 4 electromagnet, 2 - 5 impact bolt, 2 - 8 energy storage spring, 2 - 9 frame, 2 - 10 wedge block, 2 - 11 support rod pin, 2 - 12 support rod, 2 - 13 check ring, 2 - 14 rotating shaft of the support rod, 2 - 15 pull-in disk, 2 - 16 electromagnet end cover, 2 - 17 spacer bush, 2 - 18 spring pocket, 2 - 19 electromagnetic shaft, 2 - 101 electromagnet housing, 2 - 102 electromagnet mounting plate, 2 - 103 coil former, 2 - 151 conical surface, 2 - 501 inclined plane of the support rod, and 2 - 502 support rod groove.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0044] The following describes in detail preferred embodiments of the present invention with reference to the accompanying drawings.
[0045] The triggering manner shown in FIGS. 1-2 is an electromagnet and a switch (locking) mechanism, and its principle is as below: when the electromagnet is energized, the pull-in disk is picked up by electromagnetic force onto the housing of the electromagnet, at the moment, the electromagnet overcomes a downward action force F of a switch and maintains the switch in an off state. When the electromagnet loses power, the switch loses a holding power, and thus the switch is turned on under the action of the action force F. In this manner, the switch is turned on by relying on the action force of the switch (locking) mechanism, intermediate control links are less, failure rate in a control process is lower, and safety is improved due to double redundancy design.
[0046] The triggering manner shown in FIGS. 3-4 is an electromagnet and an energy storage impact mechanism, and its principle is as below: a certain distance or contact is kept between the impact bar and the switch, when the electromagnet is energized, the pull-in disk is picked up by electromagnetic force onto the housing of the electromagnet, at the moment, the electromagnet overcomes the action force of an energy storage spring and maintains the impact bar to be locked and the switch in an off state. When the electromagnet loses power, the energy storage spring is released and drives the impact bar to move downward, so that the switch is turned on. In this manner, the switch (locking) mechanism is turned on by relying on the intermediate energy storage impact mechanism in a power-off state, intermediate control links are less, failure rate in a control process is lower, and safety is improved due to double redundancy design.
Embodiment 1
[0047] Referring to FIGS. 5-6 , the frame 102 is shaped like a square frame body, and a rear side face of the frame is fixedly connected to a rear plate 118 to form a fixed mount. A left side and a right side of the frame 102 are respectively provided with a hole, an upper margin and a lower margin are also respectively provided with a hole, and a lower hole is a lower guide hole 103 . Holes corresponding to the upper margin and the lower margin of the frame 102 fit with an external shape of the impact bar 3 , the upper hole and the lower hole vertically penetrate through the impact bar 3 , and the upper hole and the lower hole are used for guiding and installing the impact bar 3 . The upper section of the impact bar 3 is shaped like a square column, and a side face is the guide surface 110 which is used for vertical guiding in a process of impacting and resetting. A middle section is also shaped like a square column, but a spacing (namely, width) between two side faces thereof is smaller than that of the upper section, the two side faces constitute an electromagnetic pull-in surface 108 , a transition edge between the electromagnetic pull-in surface 108 and the guide surface 110 is the pushing inclined plane 109 which is shaped like an (valgoid) oblique surface. Two ends of the impact bar 3 are respectively disposed outside the frame 102 . The upper end of the impact bar 3 forms a pull ring hole 111 which is fixedly connected with the manual pull ring 1 , the upper section of the impact bar 3 is also provided with a limiting buffer cushion 2 which is arranged between the manual pull ring 1 and the upper margin of the frame 102 . The lower end of the impact bar 3 is provided with an impact bolt 5 , the upward side of the impact bolt 5 is provided with a buffer cushion 105 , the impact bolt 5 is connected to the switch, and under the action of downward force, the switch is connected to the impact bar 3 by means of the impact bolt 5 .
[0048] The lower section of the impact bar 3 is externally sleeved with an impact spring 8 , and an upper end surface and a lower end surface of the spring 8 are respectively propped to the lower surface of the frame 102 and the buffer cushion 105 .
[0049] An upper edge and a lower edge of a front face of the frame 102 are each provided with a pin hole 121 for installing a pin 122 , and a cover plate is fixedly mounted on the side face through the pins.
[0050] Two side faces of the frame 102 are respectively provided with an electromagnet 4 which is fixedly mounted on the frame 102 by means of a housing 101 . An electromagnetic shaft 113 movably penetrates through one side face hole of the frame 102 , and an inner end face thereof faces the impact bar 3 , the electromagnetic shaft 113 forms an upward stepped surface 117 , and the stepped surface 117 transits to the inner end face of the electromagnetic shaft 113 by means of the inclined plane 1171 . The electromagnetic shaft 113 movably penetrates through a winding frame 114 , two ends thereof penetrate through the winding frame 114 enwound by a coil 112 , and the winding frame 114 is fixedly mounted inside the housing 101 of the electromagnet. An inner end of the electromagnetic shaft 113 is provided with a flux-insulation limit ring 115 which is arranged at one side of the stepped surface 117 (far from the inner end face), an outward side face of the flux-insulation limit ring 115 is opposite to one side face of the winding frame 114 , after moving together with the electromagnetic shaft 113 , the flux-insulation limit ring 115 may attach to or break away from a corresponding side face of the winding frame 114 ; and an inward side face of the flux-insulation limit ring 115 is provided with a retainer ring 116 externally sleeved on the electromagnetic shaft 113 .
[0051] When the electromagnet is energized, horizontal electromagnetic force is generated by forming a magnetic circuit by an end face of the electromagnetic shaft 113 and the electromagnetic pull-in surface 108 on the impact bar 3 . After the impact bar 3 is upward reset, the position of the impact bar 3 is limited by the pushing inclined plane 109 of the impact bar 3 coming into contact with the inclined plane 1171 of the electromagnetic shaft 113 , so that the impact bar 3 is locked and the impact spring 8 is in a state of compression.
[0052] After the electromagnet loses power, electromagnetic force is lost, the compressed spring 8 on the impact bar 3 generates a restoring force to form a downward driving force on the impact bar 3 , the inclined plane 1171 of the electromagnetic shaft 113 is pushed by a component force generated by the pushing inclined plane 109 , which drives the electromagnetic shaft 113 to move outward horizontally, so that the impact bar 3 is unlocked, at the moment, under the action of the impact spring, the impact bar 3 moves downward to turn on the switch (locking) mechanism.
[0053] Under the action of an external force (automatically or manually resetting) applied on the impact bar 3 , the electromagnet is energized, electromagnetic force is generated by the electromagnetic pull-in surface 108 of the impact bar 3 and the inner end face of the electromagnetic shaft 113 , so that the electromagnetic shaft 113 horizontally moves toward the impact bar 3 and is picked up together with the impact bar 3 , the impact bar 3 is locked by the inclined plane 1171 of the electromagnetic shaft 113 coming into contact with the pushing inclined plane 109 of the impact bar 3 .
[0054] The electromagnet is automatically reset, after the impact bar 3 impacts and turns on the switch, the electromagnetic shaft 113 horizontally moves outward, at the moment, the automatic pull-in amount of clearance of electromagnetic force is guaranteed by position limiting; or the a spring is applied to the electromagnetic shaft to push the electromagnetic shaft 113 to horizontally get close to the impact bar, thus ensuring that the electromagnet to automatically pick up. In the solution of this embodiment, automatic resetting may be implemented through the electromagnet by a smaller stroke, and safety is improved due to a double redundancy design.
Embodiment 2
[0055] Referring to FIGS. 7-10 , the frame 2 - 9 is shaped like a square frame body, the impact bar 2 - 3 vertically and movably penetrates through the upper edge and the lower edge of the frame 2 - 9 , two ends of the impact bar 2 - 3 are positioned outside the frame 2 - 9 , the upper end of the impact bar 2 - 3 is fixedly connected with the manual pull ring 1 - 1 , the upper section of the impact bar 2 - 3 is also provided with a limiting buffer cushion 2 - 2 , and the limiting buffer cushion 2 - 2 is arranged between the upper margin of the frame 2 - 9 and the manual pull ring 2 - 1 .
[0056] The bottom end of the impact bar 2 - 3 is provided with an impact bolt 2 - 5 , the lower section of the impact bar 2 - 3 is also sleeved with an energy storage spring 2 - 8 and a check ring 2 - 13 which is placed on the impact bolt 2 - 5 , and the upper end and the lower end of the spring 2 - 8 are respectively propped to the lower surface at the bottom edge of the frame 2 - 9 and the check ring 2 - 13 .
[0057] The energy storage spring 2 - 8 is externally sleeved with a spring pocket 2 - 18 , a lower end of the spring pocket 2 - 18 is disposed on the check ring 2 - 13 , and the height of the spring pocket 2 - 18 is smaller than the length of the spring 2 - 8 .
[0058] The middle section of the impact bar 2 - 3 is provided with a wedge block 2 - 10 which is arranged in the frame 2 - 9 , and two sides of the wedge block 2 - 10 respectively form a downward inclined plane.
[0059] Two sides of the frame 2 - 9 are respectively provided with an electromagnet 2 - 4 , and a housing 2 - 101 thereof is fixedly mounted on a side face of the frame 2 - 9 through a mounting plate 2 - 102 .
[0060] An external port of the housing 2 - 101 of the electromagnet fixes an end cover 2 - 16 . The housing 2 - 101 of the electromagnet is internally provided with a pull-in disk 2 - 15 , a first side face of the pull-in disk 2 - 15 faces an inner side face of the end cover 2 - 16 ; and another side face thereof forms a raised conical surface 2 - 151 . The housing 2 - 101 of the electromagnet is internally provided with a coil former 2 - 103 , and the electromagnetic shaft 2 - 19 movably penetrates through the coil former 2 - 103 and the mounting plate 2 - 102 , one end of the electromagnetic shaft forms a taper hole, this end faces the surface of the pull-in disk 2 - 15 , and the taper hole thereof fits with the conical surface 2 - 151 of the pull-in disk, and a clearance of 1-2 mm is kept between both when the electromagnet is not energized. One side face of the pull-in disk (with a conical surface) faces one side face of the coil former 2 - 103 . When the electromagnet is energized, electromagnetic force of the electromagnet picks the electromagnetic shaft up through the conical surface of the pull-in disk so that the electromagnetic shaft moves toward the direction of the support rod 2 - 12 . The other end of the electromagnetic shaft 2 - 19 is arranged outside the housing 2 - 101 of the electromagnet.
[0061] Rotating shafts 2 - 14 of two support rods are mounted on the bottom edge of the frame 2 - 9 , and the support rod 2 - 12 is mounted on the rotating shaft 2 - 14 of the support rod and can rotate on the rotating shaft 2 - 14 of the support rod. The rotating shaft 2 - 14 of the support rod is provided with two spacer bushes 2 - 17 disposed at two sides of the support rod 2 - 12 to relatively fix the support rod to a middle position. The upper part of the support rod forms a support rod groove 2 - 502 and an inclined plane 2 - 501 of the support rod. The inner end of the electromagnetic shaft 2 - 19 forms a groove notch which is movably sandwiched between two sides of the support rod 2 - 12 , and the groove notch is provided with a support rod pin 2 - 11 which is rotatably placed into the support rod groove 2 - 502 ; the support rod groove 2 - 502 maintains a vertical state through the support rod pin 2 - 11 under the action of the electromagnetic shaft 2 - 19 , and under the action of horizontal electromagnetic force, the impact bar is locked by the inclined plane 2 - 501 of the support rod coming into contact with the inclined plane of the wedge block 2 - 10 , so that the impact bar is unable to conduct a downward impact movement.
[0062] When the manual pull ring or an automatic reset mechanism by external force enables the impact bar to move upward to a preset position, the electromagnet is energized and electromagnetic force is maintained to be acted on the support rod, by the inclined plane of the support rod coming into contact with the inclined plane of the wedge block, horizontal electromagnetic force is converted to action force along a vertical direction, so that the impact bar is locked, and the energy storage spring on the impact bar is maintained in a state of compression.
[0063] When the electromagnet loses power, the electromagnetic shaft loses action force in the horizontal direction, at the moment, under the action of the energy storage spring, vertical action force of the impact bar is converted by the inclined planes of the wedge block and of the support rod to horizontal action force to drive the electromagnetic shaft to move to two sides, and support of the impact bar is lost so that the impact bar has an impact effect on the switch (locking mechanism) under the action of the energy storage spring to turn on the switch. This embodiment is characterized in that magnetic resetting may be implemented at smaller electric current under larger electromagnetic stroke.
[0064] In the present invention, power-off triggering is implemented by means of a manner of direct pull-in of the electromagnet or a manner of the electromagnet and the intermediate mechanism. The power-loss triggering device in the present invention turns on the switch (locking mechanism) in a power-loss (power loss) state. In a normal power-up state, electromagnetic force is maintained by means of small electric current, low power consumption and long-term energization, so that the locking mechanism is triggered to be in a working state to store energy for the impact mechanism. In case of power loss (interrupt), electromagnetic force of the electromagnet is lost, and the energy storage impact mechanism is turned on by triggering the locking mechanism so as to turn on the switch (locking) mechanism. For resetting, the impact bar of the energy storage impact mechanism is pushed upward by means of the manual pull ring or the automatic reset mechanism to compress the energy storage spring; vertical action force is converted to horizontal electromagnetic force under the action of inclined planes to implement locking of the energy storage impact mechanism by the electromagnet in a power-up state. The power-loss triggering device in the present invention is small in electric current, low in power, quick in response, stable and controllable, convenient for installation, and low in manufacturing cost, etc.
[0065] The power-loss triggering device in the present invention turns on the switch (locking) mechanism by means of a power-loss triggering manner and has the advantages in that: the switch (locking) mechanism is safely turned on in a power loss (interrupt) state, thereby solving the practical problems that the original power-on triggering safety control chain is long, the safety control risk degree is high, the failure-free monitoring links are more, it is difficult to implement power-loss triggering because of large stroke and large action force, and it is difficult to automatically reset the electromagnet.
[0066] In the manner of direct pull-in of the electromagnet, when the electromagnet loses power, the switch (locking) mechanism is turned on by means of the energy storage impact mechanism. In the manner of the electromagnet and the intermediate mechanism, an amplifying mechanism is used to reduce the holding electromagnetic force, and when the electromagnet loses power, the switch (locking) mechanism is turned on by means of the energy storage impact mechanism. The power-loss triggering device in the present invention is low in risk, small in electric current, low in energy consumption, large in impact force and stroke, and it is solved the problem of safety control of the witch (locking) mechanism.
[0067] The above describes in details preferred embodiments of the present invention, however, to those of ordinary skill in the art, the embodiments may be changed in according with the thought provided by the present invention, and these changes shall also be regarded as the scope of protection of the present invention. | The invention discloses a power-loss triggering device, including: a frame, an electromagnet and an impact bar; the impact bar vertically and movably penetrates through the frame; an energy storage piece is arranged and the energy storage piece may exert a downward action force on the impact bar; when the electromagnet is energized, the impact bar is positioned through electromagnetic force; when the electromagnet loses power, the impact bar loses a holding power from the electromagnet and conducts a downward impact movement under the action force of the energy storage piece. The power-loss triggering device is implemented through the electromagnet and an intermediate mechanism. In this invention, the electric current, the energy consumption and the cost of the electromagnet are reduced, the service life of the long-time energized electromagnet is prolonged. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This Application is a continuation-in-part of co-pending U.S. patent application Ser. No. 10/948,121, filed Sep. 23, 2004, which claims benefit of U.S. provisional patent application Ser. No. 60/505,798, filed Sep. 24, 2003. This application also claims benefit of U.S. provisional patent application Ser. No. 60/821,601, filed Aug. 2, 2006. Each of the aforementioned related patent applications are herein incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] Embodiments of the invention generally relate to methods and apparatus for increasing circulation and/or adjusting the temperature of a human. Embodiments of the invention may be used, for example, to prevent deep vein thrombosis (DVT).
[0004] 2. Description of the Related Art
[0005] Venous thromboembolic disease continues to cause significant morbidity and mortality. Hospitalization in ranges of 300,000 to 600,000 persons a year is due to venous thrombosis and pulmonary embolism (PE), originating from blood clots in the veins and some clots traveling to the lung. PE is estimated to be the third most common cause of death in the United States, resulting in as many as 50,000 to 200,000 deaths a year.
[0006] Following various types of surgical procedures, as well as trauma and neurological disorders, patients are prone to developing DVT and PE. Regardless of the original reasons for hospitalization, one in a hundred patients upon admission to hospitals nationwide dies of PE. Patients suffering from hip, tibial and knee fractures undergoing orthopedic surgery, spinal cord injury, or stroke are especially at high risk. Therefore, prevention of DVT and PE is clinically important.
[0007] Studies indicated that factors contributing to the development of DVT include reduction of blood flow, vascular stasis, increase vessel wall contact time, coagulation changes, blood vessel damage, and pooling of blood in the lower extremities. It is believed that slowing of the blood flow or blood return system from the legs may be a primary factor related to DVT with greatest effect during the intraoperative phase. Also of concern is the postoperative period. Even individuals immobilized during prolong travel on an airplane or automobile may be at risk. Generally, without mobility, return of the blood back to heart is slowed and the veins of an individual rely only on vasomotor tone and/or limited contraction of soft muscles to pump blood back to the heart. One study shows that travel trips as short as three to four hours can induce DVT and PE.
[0008] Current approaches to prophylaxis include anticoagulation therapy and mechanical compression to apply pressure on the muscles through pneumatic compression devices. Anticoagulation therapy requires blood thinning drugs to clear clots in the veins which must be taken several days in advance to be effective. In addition, these drugs carry the risk of bleeding complications. Pneumatic compression devices, which mechanically compress and directly apply positive message-type pressures to muscles in the calf and foot sequentially, are not comfortable, are difficult to use even in a hospital, and are too cumbersome for mobile patients or for use during prolonged travel. In addition, most of them are heavy weighted and there are no portable or user friendly devices.
[0009] Therefore, there remains a need for an apparatus and method to increase blood flow and/or regulate body temperature in a human which can be used in reducing clots in a human extremity and preventing deep vein thrombosis.
SUMMARY OF THE INVENTION
[0010] Embodiments of the invention provide methods and apparatus for increasing blood flow and/or controlling body temperature which can be used in preventing deep vein thrombosis. In one embodiment, a lower extremity device is provided for regulating temperature and/or providing a vacuum or a negative pressure on a human extremity, such as a leg, foot, or calf of a leg, in order to increase blood flow on the human extremity and prevent deep vein thrombosis. The lower extremity device includes a hard or soft chamber body defining a hard or soft chamber therein, a vacu-seal attached to an opening of the hard or soft chamber body for contacting a human extremity therein and providing a space between the seal and the hard or soft chamber body, and one or more apertures on the hard or soft chamber body. One or more thermal exchangers, which are placed inside the lower extremity device, permanently or detachably, are connected to one or more thermal exchange lines. The one or more thermal exchangers are also connected via one or more supply lines and return line through the one or more apertures of the hard or soft chamber body to a thermal source, a heating source, a cooling source, and/or, a thermal fluid source in order to regulate the temperature to the human extremity. In addition, one or more vacuum lines can be connected through the one or more apertures of the hard or soft chamber body to one or more vacuum pumps in order to apply vacuum to the hard or soft chamber. In another embodiment, the lower extremity device can be used in combination with a mechanical compression device or the lower extremity device can itself be modified to include one or more pressure-applying pads in order to apply mechanical compression to a lower extremity of a mammal, in addition to regulating the temperature and/or applying vacuum to the lower extremity.
[0011] In still another embodiment, a method of preventing DVT includes providing a lower extremity device to a mammal, the lower extremity device comprising a hard or soft chamber body, a seal attached to an opening of the hard or soft chamber body for contacting the lower extremity therein and providing a space between the seal and the hard or soft chamber body, and one or more thermal exchangers, regulating the temperature of the lower extremity using the lower extremity device, vasodilating an arteriovenous anastomoses (AVAs) blood vessel of the lower extremity of the mammal, and reducing the constriction of the AVA blood vessel using the lower extremity device, thereby increasing blood flow of the lower extremity and decreasing clotting within the veins. The method can further include applying mechanical compression to the lower extremity of the mammal. The method may optionally include reducing the pressure of the hard or soft chamber of the lower extremity device, such as to vacuum levels.
[0012] In a further embodiment, a method of preventing DVT includes regulating the temperature of one or more extremities of a mammal and exposing the one or more extremities to a vacuum or a reduced pressure environment.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
[0014] FIG. 1 is a cross-sectional view of one embodiment of an exemplary lower extremity device.
[0015] FIG. 2 is a section view of an exemplary seal having a foot disposed therein according to one embodiment of the invention.
[0016] FIG. 3 is a perspective view of an exemplary thermal exchange unit according to one embodiment of the invention.
[0017] FIG. 4 is a top view of another thermal exchange unit according to another embodiment of the invention.
[0018] FIG. 5 is a perspective view of another thermal exchange unit according to another embodiment of the invention.
[0019] FIG. 6 is a perspective view of an exemplary foot device according to one embodiment of the invention.
[0020] FIG. 7 is a perspective view of two exemplary foot devices according to one embodiment of the invention.
[0021] FIG. 8 is a perspective view of an exemplary leg device according to one embodiment of the invention.
[0022] FIG. 9 is a top view of another exemplary leg device of the invention.
[0023] FIG. 10 illustrates one embodiment of a control unit connected to a device according to an embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0024] Embodiments of the invention include a method and an apparatus for preventing deep vein thrombosis (DVT). In one embodiment, an apparatus for preventing deep vein thrombosis (DVT) is provided to increase blood flow in a mammal's extremity by regulating the temperature of the mammal's extremity, vasodilating an arteriovenous anastomoses (AVAs) blood vessel of the mammal's extremity, reducing constriction of the AVA blood vessel, and/or increasing vasomotor tone. In particular, the invention provides a non-invasive, convenient apparatus for efficiently adjusting the temperature, applying vacuum, and/or applying compression pressure or forces, to the mammal's extremity to increase blood flow, promote venous blood return, and reduce blood clots.
[0025] Arteriovenous anastomoses (AVAs) are specialized blood vessels located in the palms of the hands and the soles the feet which are connected to arteries and veins. Not wishing to be bound by theory, it is believed that, by heating or preventing the temperature from cooling off, to open up the AVA vessels, reduce constriction of the AVA vessels, and increase vasomotor tone, adjusting the temperature of an extremity may increase blood flow in the AVA vessels and increase venous return pressure, thereby preventing clots in the veins and preventing DVT.
[0026] In addition, embodiments of the invention provide subjecting portions of an extremity of a mammal to a reduced pressure environment, preferably under vacuum to cause dilation of vascular structures within the portions under the reduced pressure and increase blood flow, thereby reducing venous clots and preventing DVT. Apparatus according to aspects of the invention includes a hard or soft chamber body and a vacu-seal defining a hard or soft chamber space therebetween. The pressure of the hard or soft chamber space can be regulated to a level lower than atmospheric pressure, such as a pressure level of zero mm-Hg to about −120 mm-Hg.
[0027] Generally, the apparatus to increase blood flow and prevent deep vein thrombosis (DVT) includes a hard or soft chamber body defining a hard or soft chamber therein, a vacu-seal, one or more apertures in the hard or soft chamber body, and one or more thermal exchange units attached to the hard or soft chamber body through the one or more apertures. The seal may include a sealing portion attached to an opening of the hard or soft chamber body and adapted to provide a vacuum seal for the hard or soft chamber body. The seal may further include a vacu-seal body portion adapted to contact a portion of a human extremity, resulting in a hard or soft chamber space between the seal and the hard or soft chamber body such that vacuum or reduced pressure can be applied inside the hard or soft chamber space.
[0028] In one embodiment, the hard or soft chamber body is adapted to be connected between one or more thermal sources and the thermal exchange units via one or more thermal exchange supply lines and one or more thermal exchange return lines passing through at least one aperture in the hard or soft chamber body in order to regulate or maintain the temperature of the mammal's extremity. In another embodiment, the hard or soft chamber body is connected to a vacuum port and a pump via one or more additional lines through the one or more apertures in the hard or soft chamber body in order to reduce the pressure inside the hard or soft chamber space and provide a negative pressure environment that vasodilates the vasculature of the mammal's extremity. The vasodilation of the vasculature may also help to increase the thermal exchange between the one or more thermal exchange units and the mammal's extremity.
[0029] The extremity of a mammal includes legs, feet, toes, calfs, limbs, ankles, hands, etc. While embodiments of the invention will be described further below with respect to a foot device, it is recognized that the foot device described below may be adapted for use with other extremities that have vasculature structures suitable for the vasodilation methods described herein. Regulating the temperature of the mammal's extremity may include elevating and/or maintaining the temperature. The mammal may be a human or other mammal. People at high risk of DVT, PE and other conditions, such as edema, wound swelling, venous stasis ulcers, diabetic wounds, decubitous ulcer, orthopedic surgery patients, spinal cord injured individuals, among others, can benefit from the invention.
[0030] FIG. 1 is a cross-sectional view of one embodiment of a foot device 100 and a thermal exchange unit 104 . The foot device 100 includes a vacu-seal 108 and a hard or soft chamber body 102 defining a hard or soft chamber 150 to provide an enclosure in which a mammal's extremity may be positioned therein and exposed to temperature regulation and/or a vacuum environment. The thermal exchange unit 104 can be permanently or detachably placed inside the hard or soft chamber 150 to provide thermal exchange for a foot received therein.
[0031] The hard or soft chamber body 102 can be made of any durable material, such as elastomers, polycarbonates, polypropylenes, composite materials, an acrylic material, polystyrenes, high density polyethylenes (HDPE), low density polyethylenes (LDPE), poly(vinyl chloride), urethanes, polyurethanes, graphites, fiberglass, glass, rubbers, stainless steels, titanium, aluminum, light weight metal alloys (e.g., aluminum alloys, titanium alloys, etc.), polymeric materials, or any biocompatible, disposable material. The hard or soft chamber body 102 can be made of disposable low cost materials. For example, the hard or soft chamber body 102 is made of a disposable acrylic material that allows viewing of a foot positioned inside the hard or soft chamber 150 . As another example, the hard or soft chamber body 102 may be made of materials that may be sterilized via autoclaving or ethylene oxide sterilization. This is especially important if the apparatus is used during surgery where sterile conditions are very important.
[0032] The vacu-seal 108 may be made of a material that is biocompatible (and therefore safe for contact with the skin of a mammal) and capable of producing an airtight seal. In one embodiment, the vacu-seal 108 is detachably disposed inside the hard or soft chamber 150 . In another embodiment, the vacu-seal 108 is made of a disposable material, such as disposable liners or insert materials, to be used with a non-disposable hard or soft chamber body 102 . For example, the material of the vacu-seal 108 may be polyurethane, urethane, among others. One example of the seal material is PS series thermoplastic polyurethane from Deerfield Urethane, Inc. Disposable seal materials may be manufactured and packaged such that they are sterile before use. In another embodiment, the hard or soft chamber body 102 is made of non-disposable material while the vacu-seal 108 is made of disposable material to meet health and safety requirements.
[0033] The vacu-seal 108 may include a vacu-sealing portion 120 disposed around a top opening 128 of the foot device 100 to provide a hard or soft chamber space 110 between the vacu-seal 108 and the thermal exchange unit 104 . The top opening 128 is configured to receive a foot, a leg, or other extremity of a mammal. A foot disposed in the hard or soft chamber 150 is secured to the foot device 100 by the vacu-seal 108 attached to the foot device 100 through the sealing portion 120 of the vacu-seal 108 of the foot device 100 .
[0034] The hard or soft chamber space 110 inside the hard or soft chamber 150 is vacu-sealed by the vacu-sealing portion 120 and adapted to be connected to a vacuum port 112 through an aperture 114 of the hard or soft chamber body 102 . The vacuum port 112 is also adapted to be connected to a vacuum pump (not shown) for reducing the pressure of the hard or soft chamber space 110 inside the hard or soft chamber 150 . The vacuum port 112 may be covered by a protective sheath. The position of the aperture 114 can be located near any convenient portion of the hard or soft chamber body 102 . In addition, the pressure level inside the hard or soft chamber 150 can be monitored by a vacuum sensor (not shown) placed inside the hard or soft chamber space 110 with a vacuum sensor port attached to the hard or soft chamber body 102 via an aperture in the hard or soft chamber body 102 .
[0035] Accordingly, the pressure inside the hard or soft chamber 150 may be regulated in a range from atmospheric pressure to sub-atmospheric levels. For example, the hard or soft chamber space 110 inside the hard or soft chamber 150 can be adjusted to a negative pressure level, such as between about zero to about −120 mmHg, or between about −20 mmHg and about −80 mmHg, when the vacu-sealing portion 120 is vacu-sealed.
[0036] One or more thermal exchange units 104 may be provided to one or more portions of the hard or soft chamber body 102 to adjust (increase, reduce, or maintain) the temperature of the foot received therein. The thermal exchange unit 104 may include a thermal-exchange fluid medium, a heated fluid, heated air, a cooled fluid, or cooled air flown therein and provided from a fluid source (not shown) via one or more fluid supply lines. Alternatively, the thermal exchange unit may include an electric pad, as described in detail in FIGS. 3-5 . For example, the thermal exchange unit 104 may be a water heating pad having heated water flown therethrough. The one or more fluid supply lines and/or one or more fluid return lines having the thermal-exchange fluid medium flown therein between the thermal exchange unit 104 and the fluid source may pass through one or more apertures (not shown) or holes in the hard or soft chamber body 102 . The position of the apertures for the one or more fluid supply lines and the one or more fluid return lines in the hard or soft chamber body 102 can be located near any convenient portions of the hard or soft chamber body 102 and can be close to the aperture 114 or grouped together with the vacuum port 112 for passing through the hard or soft chamber body 102 via a single aperture.
[0037] The foot device 100 may further include a controller unit 160 connected to various parts of the foot device 100 for regulating the functions of the foot device 100 , including adjusting the fluid flow in and out of the thermal exchange unit 104 , regulating the temperature of the thermal exchange unit 104 , monitoring the pressure level inside the hard or soft chamber 150 via one or more vacuum sensors, adjusting the vacuum pump and the vacuum level inside the hard or soft chamber 150 , and monitoring the temperature of the foot received in the hard or soft chamber 150 , among others.
[0038] Good contact with the thermal exchange unit is important in maximizing thermal transfer to a mammal's extremity. However, the pressure differential from ambient pressure to the interior of the hard or soft chamber may cause, for example, a foot to be arched or pulled up near the sole of the foot and lose optimal contact for efficient thermal exchange. The force caused by the pressure differential is approximately equal to the area of the sole of the foot times the pressure differential. For example, the pressure differential may be approximately three pounds. In addition, the foot may be forced off the thermal exchange unit through normal jostling or positioning of the patient.
[0039] Accordingly, a flexible membrane 106 is provided between the thermal exchange unit 104 and the hard or soft chamber body 102 to enhance the surface contact between the thermal exchange unit 104 and the foot 130 . The flexible membrane 106 may collapse against the thermal exchange unit 104 under a sub-atmospheric pressure or a vacuum pressure level within the hard or soft chamber 150 . The flexible membrane 106 may comprise any suitable flexible material, for example, gas permeable thermoplastics, elastomeric materials, such as C-FLEX.RTM. (Consolidated Polymer Technologies, Inc., Largo, Fla.), DynaFlex (GLS Corporation, McHenry, Ill.), and other elastomeric materials with similar properties. In one embodiment, the flexible membrane 106 comprises a material that is temperature resistant.
[0040] FIG. 2 is a sectional view of the vacu-seal 108 having a foot 130 disposed therein. The vacu-seal 108 includes the vacu-sealing portion 120 and a body portion 122 which can be shaped to an extremity of a mammal, such as the foot 130 of a human. The vacu-sealing portion 120 is applied to the top opening 128 of the vacuum hard or soft chamber 150 by overlapping the vacu-seal 108 form the inside to the outside of vacuum hard or soft chamber 150 . The body portion 122 may be formed to conform to the shape of the foot 130 like a sock The angle α may be less than 90°, such as between about 70° to about 90°, e.g., about 75°.
[0041] In addition, there is a hole 124 provided between the vacu-sealing portion 120 and the vacu-seal body portion 122 . In one embodiment, the hole 124 is covered the ankle area of the foot 130 providing a vacuum seal between the ankle and the Vacuum hard or soft chamber. The 124 is sized to stretch (because of the material selected) to shape and size of the ankle to form a vacuum seal. There may be different shapes and sizes of the hole 124 depending on the mammal's foot.
[0042] The vacu-seal body portion 122 may include a temperature sensor 140 , which is positioned in contact with the foot 130 , for measuring the temperature of the foot 130 . A foot disposed in the foot device 100 may rest on the vacu-seal body portion 122 above the thermal exchange unit 104 . The temperature sensor 140 may be, for example, a 400 series thermistor temperature probe, available from YSI Temperature, located in Dayton, Ohio. The temperature sensor 140 is connected to the controller unit 160 of the foot device 100 . In an alternative embodiment, the vacu-seal 108 may include the thermal exchange unit. In another embodiment, the vacu-seal 108 may include an in-use sensor indicating the use of the product. In addition, the in-use sensor of the vacu-seal 108 may indicate how many times the vacu-seal 108 have been used.
[0043] The vacu-seal body portion 122 may further include an air permeable portion 126 , made of a permeable membrane material or a breathable material to permit the flow of air, etc. Examples of breathable materials are available from Securon Manufacturing Ltd. or 3M company. The permeable portion 126 may be positioned near any portion of the body portion to provide permeable outlets, allowing the vacuum to have the proper effect on the extremity and providing a barrier keeping the hard or soft chamber 150 from contamination for the comfort of the patient. As exemplarily shown in FIG. 2 , the permeable portion 126 is positioned near the toe portions of the foot 130 .
[0044] The vacu-sealing portion 120 can be wrapped around the top opening 128 of the hard or soft chamber 150 near the hole 124 of the vacu-seal 108 . A pressurized seal is ultimately formed by vacu-sealing the vacu-sealing portion 120 to the hard or soft chamber 150 and pumping air out of the vacu-sealing portion 120 of the vacu-seal 108 via an air port. In addition, the air inside the hard or soft chamber 150 can be pumped out via the vacuum port 112 connected to a vacuum pump. With the vacu-sealing portion 120 properly sealed to the foot 130 under vacuum, the negative vacuum pressure applied to the hard or soft chamber 150 via the vacuum port 112 also pulls the vacu-seal 108 away from the foot 130 because F vacu-seal and F vac act in opposition to one another, thereby reducing the total force, F total , and thus reducing the tourniquet effect. For example, a F vacu-seal of 80 mm Hg and a high F vac can reduce the F total to 40 mm Hg.
[0045] The vacu-seal 108 that seals the foot 130 under vacuum to the hard or soft chamber 150 plays an important role in the performance of the foot device because it prevents leakage of air into the vacuum or sub-atmospheric environment of the hard or soft chamber 150 . It is recognized that the vacu-seal 108 is one example of a seal that may be used with the hard or soft chamber 150 . A seal having the sealing portion with minimal leakage is preferable since it reduces the amount of air that must be continuously removed from the apparatus with an enclosed foot as vacuum is applied. However, a vacu-seal that exerts too much force on the foot may reduce or eliminate the return blood flow to the body, thus reducing the effectiveness of the foot device, and potentially creating adverse health effects. The vacu-seal 108 may also be attached to the hard or soft chamber 150 with mechanical fasteners or other fastening units. One example includes one or more mating rings which can snap into the vacuum hard or soft chamber 150 . Another example includes the use of a tape with a removable liner, such as 3M removable tapes, etc., which can be removed when ready to use.
[0046] In one embodiment, the vacu-seal 108 is a single use seal. In another embodiment, the single use seal remains attached to the hard or soft chamber after use, and the hard or soft chamber and the attached seal are disposed of after a single use. In still another embodiment, the vacu-seal 108 may be removed from the hard or soft chamber and the hard or soft chamber may be used repeatedly with another vacu-seal.
[0047] In one embodiment, the vacu-sealing portion 120 may comprise a strip of releasable adhesive tape ranging from 0.5 inches to 6 inches in width, e.g., a width large enough to cover the bottom of the foot 130 . The vacu-sealing portion 120 may have different widths along the interface between the vacu-sealing portion 120 and the vacu-seal body portion 122 . The vacu-sealing portion 120 may comprise an adhesive face and a backing portion. The vacu-sealing portion 120 is generally long enough that when wrapped end over end around the edge of the top opening, an overlap of about 0.5 inches or larger, such as about 2 inches, is present. The overlap is preferably not to encourage the user to wrap the vacu-seal around the foot too tightly and thus create a modest vacu-sealing force, e.g., less than 20 mm Hg.
[0048] The material of the vacu-sealing portion 120 may comprise a releasable adhesive material for attachment to a mammal extremity in some portion and a more permanent adhesive in other portions thereof for attaching the vacu-seal 108 to the hard or soft chamber body 102 . The releasable adhesive material may be any of a wide variety of commercially available materials with high initial adhesion and a low adhesive removal force so that the vacu-seal 108 does not pull off hair or skin and create pain when it is removed. For example, the releasable adhesive may be a single use adhesive. In addition, the adhesive material may be thick and malleable so that it can deform or give, in order to fill gaps. Adhesives with water suspended in a polymer gel, e.g., a hydrogel, are generally effective. One example of such an adhesive is Tagaderm branded 3M adhesive (part No. 9841) which is a thin (5 mm) breathable adhesive that is typically used for covering burns and wounds. Another example is an electrocardiogram (EKG) adhesive such as 3M part No. MSX 5764, which is a thicker adhesive (25 mm). The vacu-seal should fasten such that there is no leakage of the vacuum. Once a vacuum is applied, the pressure differential pulls the vacu-seal 108 closer to the foot 130 such that the vacu-seal 108 around the foot 130 is enhanced, and there is no leakage.
[0049] The backing of the vacu-sealing portion 120 may be a thin, non-elastic, flexible material. The backing supports the adhesive and keeps it from being pulled under vacuum into the appendage opening. The backing also allows the adhesive to conform to both the shape of the foot and the shape of the top opening 128 of the hard or soft chamber 150 , as well as to fold in on itself to fill gaps that may be present in the vacu-seal around the foot. Furthermore, the backing prevents the adhesive from sticking to other surfaces. Commercially available polyethylene in thicknesses up to about 10 millimeters may be used for the backing. Polyethylene that is thicker than about 10 millimeters may limit the adhesive's ability to fold on itself and fill in gaps. The backing may also comprise any polymer that may be fabricated into a thin, non-elastic, flexible material.
[0050] In one embodiment, the vacu-sealing portion 120 comprises a backing surrounded by an adhesive such that the vacu-sealing portion 120 comprises two opposing adhesive faces. For example, 3M EKG adhesive product MSX 5764 contains a supportive backing in between multiple layers of adhesive. Multiple layers of backing can also be used to provide support for the vacu-seal 108 .
[0051] Although an elastic backing may be used in the vacu-seal 108 , an elastic support backing generally creates an inferior seal compared to a non-elastic support backing because the elastic support backing reduces the ability of the adhesive to fold against itself to fill gaps and to take up excess adhesive material. Also, the elastic backing creates a greater chance that the user will over tension the vacu-seal 108 and thereby reduce blood flow.
[0052] The top opening 128 of the hard or soft chamber 150 is preferably close to the size of the patient's foot to minimize the difference in dimensions that the vacu-seal 108 must cover. The smallest opening size that will accommodate the range of acceptable foot sizes is preferred. Minimizing the opening size reduces the force on the foot created by the pressure differential between the outside of the hard or soft chamber and the inside of the hard or soft chamber since the force caused by the pressure differential is approximately equal to the area of the top opening times the pressure differential. The vacu-seal 108 is typically able to be formed of different sizes to accommodate foot sizes down to the foot size of a small adult and up to various foot sizes of a large adult. For example, multiple opening sizes, such as small, medium, and large may be used to accommodate a wider range of foot sizes.
[0053] Alternatively, the top opening 128 may be fabricated to contract within a size range without constricting blood flow in the foot to further minimize this force and make vacu-sealing easier. For example, one or more strings may be used to tighten the top opening 128 to a foot. In another embodiment, external buckles, velcos, and straps, among others, may also be used to surround the top opening 128 of the hard or soft chamber 150 secure the top opening 128 around a foot.
[0054] In another embodiment of the invention, the hard or soft chamber 150 may be collapsible for easy storage and for ease of transportation, such as to remote locations. The collapsible hard or soft chamber may be disposable. The hard or soft chamber 150 may lay flat for storage and then expand or deploy to create a three dimensional hard or soft chamber that resists collapse by negative pressure and may be made from any flexible material including polymers such as nylons, polyesters, polystyrene, polypropylene, high density polyethylene (HDPE) or any other appropriate polymer. The flexibility of the hard or soft chamber material allows the hard or soft chamber 150 to be folded for storage and expanded for use. The hard or soft chamber may be strengthened by adding supports after expansion to prevent it from collapsing against the appendage under negative pressure.
[0055] In addition, one or more portions of the hard or soft chamber body 102 may be made from transparent materials such that the functioning of the device and the condition of the foot may be monitored during use of the device. In an alternative embodiment, the hard or soft chamber body 102 may be divided into two or more body sections to be assembled into the hard or soft chamber 150 and secured by one or more fastening units, such as velcos, snaps.
[0056] FIG. 3 is an example of the thermal exchange unit 104 of the invention. The thermal exchange unit 104 includes a thermal exchange body 146 . One side of the thermal exchange body 146 includes a plurality of thermal contact domes 148 for providing thermal contact surfaces 147 directly to the vacu-seal 108 and indirectly to the foot 130 . The diameter of the thermal contact surfaces 147 and the shapes or sizes thereof can vary such that the sum of the total area of the thermal contact surfaces 147 can be increase to the maximum. The thermal exchange unit 104 may further include a thermal fluid supply line 142 and a thermal fluid return line 144 connected to a thermal fluid source for circulating a thermal fluid medium therethrough the thermal exchange body 146 of the thermal exchange unit 104 .
[0057] The material of the thermal exchange main body 146 may be any durable material which provides thermal conductivity for the thermal fluid medium flown therein and can be, for example, any of the materials suitable for hard or soft chamber body 102 . In one embodiment, the thermal exchange main body 146 is made of a flexible material which can easily conform to the shape of the foot 130 . In another embodiment, the thermal contact domes 148 are made of a rigid material to provide rigid contacts to the foot 130 .
[0058] In addition, the material of the thermal contact domes 148 may be a material which provides high thermal conductivity, preferably much higher thermal conductivity than the material of the thermal exchange main body 146 . For example, the thermal contact domes 148 may be made of aluminum, which provides at least 400 times higher thermal conductivity than plastics or rubber.
[0059] In one embodiment, the thermal exchange unit 104 can be formed and assembled through RF welding. In another embodiment, the thermal exchange unit 104 may be formed and assembled through injection molding. There are many possible ways to design and manufacture the thermal exchange unit to provide a flexible thermal exchange unit that does not leak.
[0060] FIG. 4 is another example of a thermal exchange unit 204 of the invention. The thermal exchange unit 204 may include a thermal exchange body 246 , a thermal fluid supply line 242 and a thermal fluid return line 244 connected to a thermal fluid source for circulating a thermal fluid medium through the thermal exchange body 246 of the thermal exchange unit 204 . It is contemplated that a thermal exchange unit manufactured into layers of several materials bonded together to form internal fluid flow paths for thermal fluids to be flown therein may result in uneven surfaces, due to the presence of the internal fluid flow paths, resulting in bumpy surfaces and less contacts, thereby reducing surface area needed for maximum thermal transfer. In addition, the material for the thermal exchange main body 146 , such as polyurethane, etc., may not be good conductor for thermal transfer. Thus, the thermal exchange body 246 may be covered by one or more backing sheets 248 such that flat and even contact surfaces to the foot, resulting in a large total contact area, can be provided. In addition, the backing sheet 248 can be made of high thermal conductive material to provide high thermal conductivity between the thermal exchange unit 204 and the foot 130 via the vacu-seal 108 . For example, the backing sheets 248 may be made of a thin metal sheet, such as aluminum (like a foil) or other metal sheets. In general, aluminum or other metal materials may provide higher thermal conductivity than plastics or rubber, e.g., at least 400 times higher.
[0061] FIG. 5 is another example of a thermal exchange unit 504 of the invention. The thermal exchange unit 504 may be an electric pad having one or more electric wires 542 , 544 connected to a power source. For example, the power source may be a low voltage DC current power source. In addition, the thermal exchange unit 504 may include a thermocouple 502 for monitoring the temperature and a thermoswitch 514 , which can automatically shut off the electric power when the temperature of the electric pad passes a safety level.
[0062] The thermal exchange units 104 , 204 , 504 according to embodiments of the invention generally provide thermal exchange surfaces which heat and/or regulate the temperature of an extremity of a mammal to be kept at a temperature of about 20° C. or higher, such as between about 10° C. and about 42° C. or between about 15° C. and about 40° C. It is found that different temperatures can cause blood flow to increase at different rates depending on the temperature of the skin that the device is applied to.
[0063] It is noted that one or more thermal exchange units 104 , 204 , 504 , individually or in combination, can be positioned and attached to one or more portions of the hard or soft chamber body 102 to provide thermal exchange and regulate the temperature of a mammal's extremity provided inside the hard or soft chamber 150 . In one embodiment, one or more thermal exchange units can be pre-assembled inside the hard or soft chamber 150 . In another embodiment, one or more thermal exchange units can be assembled into the hard or soft chamber 150 upon the use of a foot device.
[0064] In addition, the thermal exchange units 104 , 204 , 504 of the invention may include one or more temperature sensors and thermocouples to monitor the temperature of a mammal's extremity and provide temperature control feedback. For example, a tympanic temperature probe may be inserted to other body portions, such as ear canal, etc., of a mammal to monitor core body temperature and provide the core temperature feedback to the controller unit 160 .
[0065] FIG. 6 is a perspective view of one example of another foot device 600 . The foot device 600 includes a hard or soft chamber body 602 , a supply line 642 , a return line 644 , and a vacuum port 612 . As shown in FIG. 6 , one or more tubings, lines, and ports can be bundled together into a tubing set 670 and connected to a controller unit (not shown) for easy transportation and operation.
[0066] FIG. 7 is a perspective view of two exemplary foot devices 700 and 710 which can be about the same size and fitted for a right or a left foot. Alternatively, the foot devices 700 and 710 can be manufactured into different sizes suitable for various foot sizes.
[0067] FIG. 8 illustrates another example of a leg device 800 of the invention. The leg device 800 may include an upper hard or soft chamber body 802 A and a lower hard or soft chamber body 802 B which form an upper hard or soft chamber 850 A and a lower hard or soft chamber 850 B, respectively. The leg device 800 may also include a flexible portion 803 , providing a flexible connection between the upper hard or soft chamber body 802 A and the lower hard or soft chamber body 802 B. In addition, there can be pressure air line and fluid tubing inside the flexible portion 803 connecting through the upper hard or soft chamber 850 A and the lower hard or soft chamber 850 B. The flexible portion 803 may be made of a flexible material to provide flexibility for a leg 830 of a mammal to be positioned inside the leg device 800 . For example, the flexible portion 803 may be snugly fitted near the ankle section of the leg 830 . Alternatively, the upper hard or soft chamber 850 A and the lower hard or soft chamber 850 B may be formed into one single vacuum hard or soft chamber. In another embodiment, the leg device 800 may include two or more individual devices, such as a foot device and a calf device, having the upper hard or soft chamber 850 A and the lower hard or soft chamber 850 B, respectively.
[0068] The leg device 800 may also include one or more thermal exchange units (not shown) and flexible membranes attached to one or more portions of the upper hard or soft chamber body 802 A and the lower hard or soft chamber body 802 B. A vacu-seal can be detachably or permanently installed inside the leg device 800 as a liner for the leg 830 and may include a vacu-sealing portion 820 near a top opening of the leg device 800 for sealing the leg device to the leg 830 under vacuum.
[0069] In addition, the leg device 800 may include one or more compression pads 860 around one or more portions of the upper hard or soft chamber 850 A and the lower hard or soft chamber 850 B. Each compression pad 860 may include one or more air pockets connected to gas lines and gas sources to be filled with air or various fluids when the leg 830 is positioned inside the leg device 800 . In addition, the air pockets on the compression pad 860 can alternatively be pumped with air or fluids to provide a bellow-like motion to apply various compression pressures or pressurized forces on portions of the leg 830 intermittedly, consecutively, or otherwise in a time appropriate manner. It is believed that applying pneumatic compression pressure or pressurized force on portions of the leg 830 may increase blood flow within the leg, prevent clotting and blood pooling in the veins, and prevent deep vein thrombosis.
[0070] One or more thermal fluid supply lines, return lines, electric lines, sensor lines, gas lines, temperature sensor ports, vacuum ports, and vacuum sensor port, can be provided to the leg device 800 via one or more apertures in the upper hard or soft chamber body 802 A and/or the lower hard or soft chamber body 802 B. These tubings, fluid lines, electric lines, gas lines and vacuum ports can be bundled together into a tubing set 870 through an aperture 872 on the hard or soft chamber body and connected to the controller unit 160 for easy transportation and operation.
[0071] FIG. 9 is another example of a leg device 900 of the invention. The leg device 900 may include a hard or soft chamber body 902 and an occlusion cuff 920 proximate the top portion of the hard or soft chamber body 902 . The hard or soft chamber body 902 can be conveniently assembled through fasteners 980 , 982 , 984 , 986 , 988 before or after a leg is positioned therein. The fasteners of the invention can be, for example, snaps, tabs, clips, tongs, adhesives, Velcro, among others, to join the hard or soft chamber body 902 together.
[0072] The leg device 900 may be used together with a vacu-seal having a sealing portion for attaching to the occlusion cuff 920 and providing a vacu-seal between the leg device 900 and the leg. The leg device may also be used without a vacu-seal and the occlusion cuff 920 is provided for sealing the leg device 900 to the leg.
[0073] The hard or soft chamber body 902 defines a hard or soft chamber 950 having one or more thermal exchange units 904 positioned therein. The one or more thermal exchange units 904 may be a fluid pad having a thermal fluid medium flown therein, an electric pad, or any other suitable thermal exchange units, individually or in combination. Thermal energy can be transferred from the thermal exchange unit 904 to the leg for heating or cooling the leg.
[0074] The leg device 900 further includes one or more compression pads 960 A, 960 B, 960 C, each having one or more air pockets connected to air lines and air sources for applying pneumatic compression pressure onto portions of the leg. The one or more thermal exchange units and compression pads of the leg device 900 can be positioned overlappingly or separately on one or more portions of the hard or soft chamber body 902 inside the hard or soft chamber 950 .
[0075] In operation, a foot, a leg, or a lower extremity is fitted into a vacu-seal and then the lower extremity covered with the vacu-seal is positioned in a lower extremity device. Alternatively, a detachable vacu-seal may first be assembled inside a lower extremity device before a lower extremity is fitted to the assembled lower extremity device. In addition, one or more detachable thermal exchange units may be pre-assembled inside a lower extremity device or may be assembled upon positioning a lower extremity into the lower extremity device. Then, a vacu-sealing portion of the vacu-seal is wrapped around a top opening of the foot device to form a tight seal and prevent air from entering the space between the foot and the foot device.
[0076] FIG. 10 illustrates one embodiment of the control unit 160 connected to various parts of a device 300 of the invention. A controller module 360 having the controller unit 160 therein houses all the electronics and mechanical parts which are required to regulate the temperature, vacuum pressure level, and compression pressurized force provided to the hard or soft chamber 150 of the device 300 . The controller module typically includes, for example, a vacuum pump 332 , a vacuum pump 334 , a thermal exchange medium source 336 , a fluid flow sensor 352 , a thermal exchange medium pump, a heater, a cooler, thermocouples, a heating medium pump, a proportional-integral-derivative (PID) controller for process control of the vacuum and the temperature, one or more power supplies, display panels, actuators, connectors, among others, to be controlled by the controller unit 160 . The settings of the controller unit 160 may be conveniently positioned onto a display panel which provides an operator interface. The controller unit 160 may contain additional electronics for optimal operation of the device 300 of the invention. In alternative embodiments, the vacuum control and temperature control may be controlled by two different controllers.
[0077] The controller unit 160 may provide safety features including a device shutdown feature that is activated if the device sensors, such as the temperature and pressure sensors, fail or become disconnected. The controller unit 160 may also include an alarm circuit or an alert signal if the temperature of the apparatus is not regulated correctly. A relief valve may be provided within the vacuum loop of the device such that the hard or soft chamber may be vented if the vacuum within the hard or soft chamber exceeds a certain level.
[0078] In one embodiment, a temperature probe 362 can be provided to measure the temperature of a portion of a mammal other than a foot, leg, or other extremity where the device is attached to. For example, a tympanic membrane can be attached to the ear canal as a temperature probe to provide core temperature reading. As such, a reference temperature for the human, such as a patient, can be obtained. Other sensors may include patient's blood flow and blood pressure and heart rate. These data are important to proper patient health care in keeping DVT from forming and keeping the patient at normal temperature range.
[0079] As shown in FIG. 10 , the vacu-sealing portion 120 can be connected to the vacuum pump 332 via a vacuum port 324 to provide a vacu-seal pressure, F vacu-seal , thereto. The hard or soft chamber 150 can be connected to the vacuum pump 334 via a vacuum port 312 and a vacuum sensor return line 322 to provide a vacuum pressure or a negative pressure inside the hard or soft chamber 150 .
[0080] In addition, the hard or soft chamber having one or more thermal exchange units therein may be connected to the thermal exchange medium source 336 via a thermal exchange medium supply line 342 and a thermal exchange medium return line 344 . Further, the flow of a thermal exchange medium flown inside the thermal exchange medium supply line 342 can be monitored and regulated by the fluid flow sensor 352 .
[0081] These lines and ports of the invention may be bundled, contained, and strain-relieved in the same or different protective sheaths connected to the controller unit 160 . The lines may also be contained in the same or different tubing set with different enclosures for each medium used, such as fluid, vacuum, electric heat, and air lines.
[0082] In one embodiment, the thermal exchange units are coupled in a closed loop configuration with the thermal exchange medium source which provides a thermal exchange medium. For example, the thermal exchange unit may be coupled in a closed liquid loop configuration with a liquid tank housed within the controller module 360 . The closed loop configuration reduces the maintenance requirements for the operator because it minimizes the loss of thermal exchange medium that typically occurs if the thermal exchange unit is detached from the thermal exchange medium source. Contamination of the thermal exchange medium source is also minimized by the closed loop configuration. Contamination of the thermal exchange medium such as water can also be reduced by adding an antimicrobial agent to the thermal exchange medium source. In different embodiments, the thermal exchange medium may be either a liquid or a gas. In practice, the thermal exchange medium flow rate should be as high as possible, within practical limits of mechanics and noise. A high flow rate allows better temperature consistency, results in less thermal loss, and creates better thermal exchange. In a closed loop configuration including the thermal exchange unit and the thermal exchange medium source, with a total system volume of 0.75 liters, a flow rate of 2 liters a minute transfers twice as much fluid through the thermal exchange unit than a flow rate of 0.35 liters per minute.
[0083] In an alternative embodiment, the thermal exchange unit and vacuum lines may be connected to the control unit using actuated fittings such as quick release fittings with an automatic shut off mechanism. The automatic shut off mechanism halts the vacuum application and the heating medium flow as soon as the vacuum lines are disconnected. Actuated fittings may also allow the operator to change thermal exchange units.
[0084] The embodiments of the apparatus described above provide a method of increasing blood flow in one or more extremities of a mammal and decreasing clots within the veins in order to prevent deep vein thrombosis (DVT). The method includes providing one or more devices of the invention to the mammal and regulating the temperature of the one or more extremities of the mammal using the devices. As a result, one or more arteriovenous anastomoses (AVAs) blood vessels inside an extremity of a mammal are vasodilated, and constriction of the AVA blood vessels is reduced, thereby increasing blood flow and blood volume in the one or more extremities, decreasing the vessel wall contact time of the blood flow, and decreasing clots in the veins due to pooling. In one embodiment, a suitable portion of an extremity, preferably an extremity with vasculature that can be vasodilated by the device, such as a foot, may be placed into a device and sealed therein.
[0085] Once the foot is enclosed in the hard or soft chamber, negative pressure is applied to a vacuum port thereby lowering the pressure within the hard or soft chamber and exposing the foot to decreased pressure in the range of zero to about −120 mm-Hg, such as from about −10 mmHg to about −50 mm-Hg below atmospheric pressure. Simultaneously or sequentially, the thermal exchange medium is introduced into the thermal exchange unit positioned inside the hard or soft chamber body. The flow rate of the vacuum pump may be greater than about 4 liters per minute, and preferably about 12 liters per minute or more. In one aspect, the flow rate of the vacuum pump is between about 4 liters and about 20 liters per minute and is preferably between about 12 and about 20 liters per minute to minimize leakage of the apparatus. The negative pressure also enhances the sealing of the device by increasing the closing pressure on the sealing portion of the device and between the hard or soft chamber and the foot.
[0086] In one embodiment, the controller unit manages the thermal exchange medium and negative pressure for the duration of the treatment, which may be about 30 minutes, for example. The duration may be longer or shorter depending on the size of the foot or leg treated and the temperature of the foot or leg, and may be repeated. In some cases, the duration of the treatment may be cycled time period, for example, a time period of 1-5 minutes or longer for 5 cycles or longer. The controller is configured to halt the treatment after each treatment period. A “stop” button on the control unit may be used to turn off both the thermal exchange medium supply and the vacuum.
[0087] Embodiments of the invention may be used to increase blood flow of a patient in order to prevent DVT. Embodiments of the invention may also be used to regulate the temperature of a patient. In such a method, the temperature of the thermal exchange medium should be as high as possible without burning the patient. In a healthy patient, burning of the cells on the appendage can occur if the cell temperature exceeds about 43 degrees Celsius (° C.), but this may vary with exposure time and rate of thermal transfer. Therefore, the temperature of the thermal exchange medium is preferably calibrated such that skin temperature is maintained at less than 43 degrees Celsius. For example, different people have different tolerance levels for different temperature ranges, according to their ages, health conditions, etc. In addition, the device can be used for heating and maintaining the temperature of a patient as well as cooling. In general, a temperature range between about 10° C. to about 42° C. can be maintained.
[0088] Furthermore, the negative pressure is preferably as great as possible to maximize vasodilation, without restricting blood flow to the extremity. However, higher levels of temperature and negative pressure may cause pain in some patients because of sensitivity to temperature and sensitivity to negative pressure. Additionally, sensitivity to temperature and negative pressure may be increased with extended treatment time or repeated treatments. Furthermore, some patients may be prone to petechia, a condition in which capillaries microburst under negative pressure.
[0089] Consequently, in order to reduce patient discomfort, the controller may be configured with different temperature and vacuum settings. In one embodiment, one treatment setting is “High”, which includes the highest temperature and negative pressure setting. “Medium” and “Low” settings have progressively lower settings for temperature and/or negative pressure. Patients who are at high risk for petechia or who are being treated for an extended amount of time may be treated on the “Low” setting. The vacuum setting may be adjusted to provide less negative pressure in patients that are under anesthesia since they are already vasodilated, while the temperature is kept at a higher setting. In a further aspect, the device may use between about 5 watts and about 250 watts of energy power to raise a body core temperature at a rate of between about 4° C./hour and about 12° C./hour. Preferably, the power applied is between about 5 watts and about 80 watts, although a power of up to about 250 watts may be used. In contrast, a convective warming blanket that heats the whole body may use about 500 watts.
[0090] While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow. | A method and apparatus for the prevention of deep vein thrombosis (DVT), pulmonary embolism (PE), lower extremity edema, and other associated medical conditions by adjusting the temperature of the muscles of a foot or a leg, and/or applying vacuum or negative pressure to increase blood flow. A human extremity such as a leg is exposed to a negative pressure environment and/or a thermally controlled environment within a medical device. In one aspect, the device is portable. A thermal exchange unit and, optionally, a vacuum or negative pressure unit, are provided to increase blood flow and vasodilation. The device can be programmed by a controller in a manner to stimulate the muscles of the extremity to reduce pooling of blood therein. | 0 |
FIELD OF THE INVENTION
[0001] The invention relates to a tire pressure monitoring system (TPMS) in a motor vehicle, in particular to a sensor for a tire pressure monitoring system in a motor vehicle, and a setting method and a setter thereof.
BACKGROUND OF THE INVENTION
[0002] TPMS is shorted for Tire Pressure Monitoring System, comprising a sensor arranged in a tire and a receiving and processing unit arranged in a motor vehicle, used for monitoring data (for example, pressure and temperature etc) related to the tire, and informing a driver for a timely handling in the form of sound and image (text description) in the event of abnormal change of data related to the tire. TPMS is based on the operating principle that data related to the tire is subject to acquisition and processing by the sensor, the processed data is then sent by wireless means in a special data format to the receiving and processing unit in the motor vehicle, and then the receiving and processing unit decodes the data received and displays relevant information.
[0003] Since its appearance in 2000, TPMS has been subject to upgrade and improvement for many times. At present, the most popular TPMS consists of four sensors and a receiving processor, referred to as a direct-type TPMS, in which, a TPMS sensor is a critical component in the TPMS. The battery-powered TPMS sensor can be generally used 5-7 years. Therefore, it is necessary to replace it with a new TPMS sensor after a certain time. At present, there are 6-7 suppliers in the world supplying TPMS for the original motor vehicle manufacturer. Since 2000, TPMS has been subject to continuous design and update and developed into 60-70 different types. Each sensor has different data formats for sending signals. The major problem is different sensors are non-interchangeable, and a certain sensor may be only used in a certain type of motor vehicle. Therefore, an auto repair shop may store many different types of sensors for different types of vehicles waiting for maintenance in future. Thus, it is inconvenient for both the auto repair shop and final consumers. Furthermore, it is inconvenient to replace a damaged sensor or a battery-exhausted sensor.
[0004] For the above-mentioned problems, there is a solution in the past, namely, a plurality of encoding procedures is installed in a sensor in advance. When in use, the above-mentioned encoding procedures encode data acquired in sequence, and the sensor sends the data immediately once it is encoded until the data format is correct. The solution can reduce trouble for the auto repair shop. However, the sensor has a great deal of data to be processed, and the above-mentioned steps must be repeated every time when the motor vehicle is restarted, which causes large power consumption, also the sensor has higher requirements for its hardware configuration but shorter service life.
[0005] For the above-mentioned problems, there is another solution in the past, namely, no encoding procedure is stored in a sensor, and an auto repair shop is equipped with a sensor setter. When an auto needs repairing in the auto repair shop, the setter selects an encoding procedure and sends it to the sensor on the spot. This solution not only solves the above-mentioned problems but also eliminates disadvantages of the previous solution. However, the sensor may be easily imitated by lawbreakers, thus causing loss of the owner's rights and interests.
SUMMARY OF THE INVENTION
[0006] One technical problem that the invention aims at solving is to provide a method for setting a sensor for a tire pressure monitoring system in a motor vehicle, which not only can solve the problem puzzling auto repair shops, but also can avoid disadvantages of the above-mentioned background art. For this purpose, the invention adopts the technical scheme described below.
[0007] According to one aspect of the invention a method includes providing the sensor in which a plurality of encoding procedures is stored in advance;
[0008] The method also includes a step for providing a sensor setter in which encoding procedure processing instruction sent to the sensor is stored, sending encoding procedure processing instruction to the sensor by wireless or wired means by the setter once or more than once, and the sensor receiving the encoding procedure processing instruction, on the basis of which, all other encoding procedures except the required encoding procedure processing instruction are processed once for all or processed one by one, in this way, the processed encoding procedures are subject to deletion or failure of encoding or failure of invoking for encoding.
[0009] Further, the encoding procedure processing instruction is a program deletion instruction, or a program modification instruction or an encoding procedure selection instruction.
[0010] Further, the setter sends the encoding procedure processing instruction integrally to the sensor by multiple match codes, namely by the way of sending program bytes.
[0011] Further, an encoding procedure lock-in instruction is stored in the setter, and the method also includes, before or after or at the same time of sending the encoding procedure processing instruction, the setter sends the encoding procedure lock-in instruction to the sensor by wireless or wired means, after receiving the encoding procedure lock-in instruction and before processing other encoding procedures except the required encoding procedure, the sensor locks the required encoding procedure, in this way, it is impossible to delete or modify the required encoding procedure.
[0012] Alternatively, the method also includes wherein the sensor locks the required encoding procedure by responding to an induction signal, in this way, it is impossible to delete or modify the required encoding procedure.
[0013] Another technical problem that the invention aims at solving is to provide a sensor for a tire pressure monitoring system in a motor vehicle for realization of the above-mentioned method. For this purpose, the invention adopts the following technical scheme.
[0014] A sensor for a tire pressure monitoring system in a motor vehicle includes a data processing unit, an electrically erasable memory cell, a sensor unit, at least comprising a pressure sensor, and a data transmission unit, wherein the data processing unit is internally provided with an electrically erasable encoding procedure memory module in which a plurality of encoding procedures are stored wherein the data processing unit is also provided with an encoding procedure processing module which is used for processing unwanted encoding procedures in the encoding procedure memory module on the basis of encoding procedure processing instruction, in this way, the unwanted encoding procedures are subject to deletion or failure of encoding or failure of invoking for encoding, and wherein the unwanted encoding procedures are encoding procedures except the required encoding procedures.
[0015] Further, the data processing unit is also internally provided with an encoding procedure lock-in module which is used for, on the basis of the encoding procedure lock-in instruction or the responsive induction signal, locking the required encoding procedures so that it is impossible to delete or modify the required encoding procedures.
[0016] Further, the data transmission unit comprises a wireless data transmission module or a wired data transmission module additionally.
[0017] Another technical problem that the invention aims at solving is to provide a sensor setter for a tire pressure monitoring system in a motor vehicle for realization of the above-mentioned method. For this purpose, the invention adopts the following technical scheme.
[0018] The sensor setter for a tire pressure monitoring system in a motor vehicle includes a data processing unit, a data input unit, and a data transmission unit, wherein the setter is provided with an encoding procedure processing instruction memory module for invoking the data processing unit, the encoding procedure processing instruction is stored in the encoding procedure processing instruction memory module and wherein the data transmission unit, on the basis of the instruction from the data processing unit, outward transmits the encoding procedure processing instruction stored in the encoding procedure processing instruction memory module.
[0019] Further, the setter is provided with an encoding procedure lock-in instruction memory module for invoking the data processing unit, the encoding procedure lock-in instruction is stored in the encoding procedure lock-in instruction memory module; the data transmission unit, on the basis of the instruction from the data processing unit, outward transmits the encoding procedure lock-in instruction stored in the encoding procedure lock-in instruction memory module.
[0020] Further, the data transmission unit comprises a wireless data transmission module or a wired data transmission module additionally.
[0021] Due to adoption of the technical scheme, a plurality of optional encoding procedures is stored in advance in the sensor provided by the invention. Only data encoded by the encoding procedure is required to be emitted when the sensor is applied to tire pressure measurement for a motor vehicle, thus not only solving the problem characterized by large data processing and large power consumption, but also preventing the sensor from being counterfeited by lawbreakers easily. The sensor is suitable for the method for setting a sensor for a tire pressure monitoring system in a motor vehicle provided by the invention.
[0022] Due to adoption of the technical scheme, the setter provided by the invention is suitable for the method for setting a sensor for a tire pressure monitoring system in a motor vehicle provided by the invention. Only data encoded by the encoding procedure is required to be emitted when the sensor is set for application, thus not only solving the problem characterized by large data processing and large power consumption, but also preventing the sensor from being counterfeited by lawbreakers easily.
[0023] Due to adoption of the technical scheme, by virtue of the method provided by the invention, the sensor is provided with a plurality of optional encoding procedures. Only data encoded by the encoding procedure is required to be emitted when the sensor is set for application, thus not only solving the problem characterized by large data processing and large power consumption, but also preventing the sensor from being counterfeited by lawbreakers easily.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 is a schematic diagram of the sensor and the setter in the embodiment of the invention;
[0025] FIG. 2 is a flow diagram showing the sensor for encoding procedure processing and locking in the embodiment of the invention; and
[0026] FIG. 3 is a flow diagram showing the setter for transmitting the encoding procedure processing instruction and lock-in instruction in the embodiment of the invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0027] By reference to FIG. 1 , the sensor for a tire pressure monitoring system in a motor vehicle is internally provided with a data processing unit 102 , an electrically erasable memory cell 104 , a sensor unit 106 , at least comprising a pressure sensor 108 , and a data transmission unit 110 .
[0028] The data processing unit is internally provided with an electrically erasable encoding procedure memory module in which a plurality of encoding procedures are stored. The data processing unit is also provided with an encoding procedure processing module which is used for, on the basis of encoding procedure processing instruction, processing unwanted encoding procedures in the encoding procedure memory module, in this way, the unwanted encoding procedures are subject to deletion or failure of encoding or failure of invoking for encoding; the unwanted encoding procedures are encoding procedures except the required encoding procedures.
[0029] In addition to a pressure sensor 108 , the sensor unit 106 can also be provided with a temperature sensor 112 , an acceleration sensor 114 and other sensors used for data acquisition. The sensor unit 106 is mainly used for collecting relevant data information and sending it to the data processing unit 102 . By using processed remaining encoding procedures, the data processing unit 102 encodes and integrates, on the basis of executed protocol, the data required to be sent, and sends the data integrated to certain data format, by means of the data transmission unit 110 , to an ECU in a motor vehicle.
[0030] The data transmission unit includes a wireless data transmission module or a wired data transmission module 116 and additionally is mainly used for providing a data transmission carrier for response commands, and meanwhile providing a data path for the response commands. The wireless data transmission module comprises a high-frequency data channel 118 and a low-frequency data channel 120 , in which, one is used for receiving data sent from the setter and feedback data sent from the ECU in a motor vehicle, while the other is used for receiving response signal after the setter sending data and for sending data to the ECU in a motor vehicle.
[0031] The data processing unit 102 can be a microprocessor which is provided with an electrically erasable encoding procedure memory module and an encoding procedure processing module, and further provided with an encoding procedure lock-in module.
[0032] At the phase of sensor setting, on the basis of the encoding procedure processing instruction from the data transmission unit 102 , the encoding procedure processing module is used to process those unwanted encoding procedures in the encoding procedure memory module, so that the unwanted encoding procedures in the encoding procedure memory module are subject to deletion or failure of encoding or failure of invoking for encoding. Furthermore, on the basis of the encoding procedure lock-in instruction from the data transmission unit, the encoding procedure lock-in module is used to lock those required encoding procedures, so that the required encoding procedures are impossibly subject to deletion or modification. The lock-in instruction can be either an instruction requiring the sensor to lock the required encoding procedures or a signal indicating that the setter completely sends the encoding procedure processing instruction, on the basis of which, the encoding procedure lock-in module locks the required encoding procedures.
[0033] At run phase, responding to induction signal from the sensor unit, remaining required encoding procedures not processed by the encoding procedure processing module are used after the setting phase in the encoding procedure memory module to process signal information from the sensor unit and other data required to be sent, and to send the processed data to the data transmission unit.
[0034] The electrically erasable memory cell can store data collected by the pressure sensor unit and other sensor units.
[0035] The encoding procedure processing instruction can be an instruction to process one or one group of encoding procedure selected, namely, at the setting phase, the sensor receives a plurality of encoding procedure processing instructions for respective requirement for processing different encoding procedures, in this way, the encoding procedure processing module processes the encoding procedures one by one until only those required encoding procedures remained. The encoding procedure processing instructions also aim at all other encoding procedures except those required encoding procedures, in this way, the encoding procedure processing module processes all unwanted the encoding procedures at one time, with only required encoding procedures left.
[0036] The encoding procedure processing instruction can be a program deletion instruction, or a program modification instruction or an encoding procedure selection instruction, in which, the method for modification as for the program modification instruction includes but not limited to: modulation mode, data width, bit wide, function code, pressure range, checkout, data head code and data algorithm, etc. After the data processing unit responds to the relevant instruction, encoding procedures in the encoding procedure module arae subject to modification according to the above-mentioned methods, so that the encoding procedures are impossible for encoding or invoking for encoding. As for the encoding procedure selection instruction, when the sensor receives the instruction, the encoding procedure processing module of the sensor processes those encoding procedures selected by the encoding procedure processing module from encoding procedure selection instruction and those encoding procedure except these selected encoding procedures.
[0037] Referring again to FIG. 1 , the sensor setter 126 for a tire pressure monitoring system in a motor vehicle includes a data processing unit 128 , a data input unit 130 , and a data transmission unit 132 .
[0038] The setter is provided with an encoding procedure processing instruction memory module 122 for invoking the data processing unit. The data transmission unit 132 , on the basis of instruction from the data processing unit, outward transmits the encoding procedure processing instruction stored in the encoding procedure processing instruction memory module 122 .
[0039] Further, the setter 126 is provided with an encoding procedure lock-in instruction memory module 124 for invoking the data processing unit. The data transmission unit, on the basis of instruction from the data processing unit, outward transmits the encoding procedure lock-in instruction stored in the encoding procedure lock-in instruction memory module.
[0040] The data processing unit can be a microprocessor which is mainly used for generating different instructions according to different needs, for sending the instructions to the sensor by virtue of the data transmission unit and meanwhile receiving feedback signal sent from the sensor.
[0041] The data input unit 130 is used for establishing a bridge for intercommunication between the data processing unit and outer computers, for convenience of updating the programs in the encoding procedure processing instruction memory module, the programs in the encoding procedure lock-in instruction memory module, and other programs run by the setter.
[0042] The data transmission unit 132 comprising a wireless data transmission module or a wired data transmission module 134 and additionally is mainly used for establishing a bridge for data communication between the setter and the sensor. The wireless data transmission module includes a low-frequency emitter 136 used for sending the encoding procedure lock-in instruction and other instructions to the sensor, and a high-frequency emitter/receiver 138 used for sending feedback signal to the sensor and receiving feedback signal from the sensor.
[0043] A method for setting a sensor for a tire pressure monitoring system in a motor vehicle includes providing the sensor in which a plurality of encoding procedures is stored in advance, and providing a sensor setter in which encoding procedure processing instruction sent to the sensor is stored. The encoding procedure processing instruction is a program deletion instruction, or a program modification instruction or an encoding procedure selection instruction. The method also includes sending the encoding procedure processing instruction to the sensor by wireless or wired means by the setter once or more than once In the embodiment, the setter sends the encoding procedure processing instruction integrally to the sensor by multiple match codes, just as shown in FIG. 3 .
[0044] 1-1. Users, on the basis of motorcycle type, choose applicable encoding procedure processing instructions.
[0045] 1-2. The data transmission unit, on the basis of instructions from the data processing unit, sends a piece of encoding procedure processing instruction.
[0046] 1-3. The setter waits for security code signal fed back from the sensor.
[0047] The above-mentioned steps shall be continued to be repeated in case of validity of verification until an integral encoding procedure processing instruction is sent out. However, the above-mentioned steps shall be restarted in case of invalidity of verification.
[0048] Furthermore, in the method the sensor receives the encoding procedure processing instruction, on the basis of which, all other encoding procedures except the required encoding procedure processing instruction are processed once for all or processed one by one, in this way, the processed encoding procedures are subject to deletion or failure of encoding or failure of invoking for encoding. Please refer to FIG. 2 , specifically as follows:
[0049] 2-1 The sensor waits for the encoding procedure processing instruction sent from the setter.
[0050] 2-2. After receiving information sent from the setter, the sensor feeds back signal.
[0051] 2-3. The data processing unit of the sensor carries out verification, the next step is started if the encoding procedure processing instruction is sent correctly or integrally; otherwise, the information is fed back to the setter.
[0052] The above-mentioned steps shall be repeated until integral encoding procedure processing instruction is received.
[0053] 2-4. The data processing unit of the sensor, on the basis of the encoding procedure processing instruction, processes the encoding procedures, in this way, the unwanted encoding procedures are subject to deletion or failure of encoding or failure of invoking for encoding.
[0054] An encoding procedure lock-in instruction is stored in the setter The method also includes, before or after or at the same time of sending the encoding procedure processing instruction, the setter sending the encoding procedure lock-in instruction to the sensor by wireless or wired means. As is illustrated in FIG. 3 , after the final piece of the encoding procedure processing instruction is sent, the data transmission unit of the setter, on the basis of instruction from the data processing unit of the sensor, sends the encoding procedure lock-in instruction.
[0055] Referring to FIG. 2 , after receiving the encoding procedure lock-in instruction and before processing other encoding procedures except the required encoding procedure, the sensor locks the required encoding procedure, in this way, it is impossible to delete or modify the required encoding procedure.
[0056] Before the sensor is installed in the tire or before the tire rolls, the above-mentioned lock-in steps are carried out according to instruction or signal from the setter as required. During implementation, the sensor can also be automatic subject to encoding procedure lock-in on the basis of external induction signal. For example, after the tire rolls, the data processing unit of the sensor responds to external induction signal such as acceleration and pressure signals etc., after which, the encoding procedure lock-in module automatically executes encoding procedure lock-in, specific steps are seen as below:
[0057] 1. The data processing unit of the sensor receives signal sent from the acceleration sensor for response of tire rotation.
[0058] 2. The data processing unit of the sensor responds to the signal sent from the acceleration sensor for response of tire rotation and invokes the encoding procedure lock-in module to lock the required encoding procedures, in this way, it is impossible to delete or modify the required encoding procedure. | A method for setting a sensor for a tire pressure monitoring system in a motor vehicle, includes storing a plurality of encoding procedures is stored the sensor. By sending instructions to the sensor by the setter, all other encoding procedures except the required encoding procedures from a plurality of encoding procedures stored in advance in the sensor are processed, neither able to be encoded nor to be invoked for encoding. Furthermore, during application, data encoded by an encoding procedure is required to be sent out, thus not only solving the problem characterized by large data processing and large power consumption, but also preventing the sensor from being counterfeited by lawbreakers easily. | 1 |
[0001] This application claims priority from U.S. application Ser. No. 60/677,694 filed May 4, 2005 and is a continuation-in-part application of U.S. application Ser. No. 11/215,919 filed Aug. 25, 2005, both of which are incorporated herein by reference in their entireties.
FIELD OF THE INVENTION
[0002] The present invention is an apparatus for cleaning human waste by flushing water to the anus after rest room visits and method of using the same.
BACKGROUND OF THE INVENTION
[0003] In many places, cultural and religious beliefs require cleaning the anus with water after rest room visits. Additionally, many whose religious and cultural beliefs do not require such cleaning nevertheless find it desirable to perform such cleaning. Containers are conventionally used to transport water to the anus and the hand is directly involved in the cleaning process. Many bidets are available that provide directed water flow to the anus to assist in the manual cleaning. When such bidets are used, typically only cold water is used. Also, the bidet requires use of a hand directly or indirectly to complete cleansing. Also, sometimes water hoses are used. Even where water hoses are used to provide water, it had been customary to use only cold water. Usually the user holds the hose with one hand and uses the other hand to remove waste from the anus.
[0004] It is desirable to find a manner of cleaning human waste from the anus that does not require that the hands be directly involved. Such a device would provide improved standards of cleanliness. Clearly, the need to find a better way of cleaning human waste has become an issue in some parts of the world, such as in many Muslim regions, where anal cleaning is required by religious and cultural standards. Furthermore, it is desirable to improve the comfort of such cleaning by allowing for temperature control of the cleaning water. Also, it is desirable to find a cleaner alternative to using toilet paper. It is preferred that the improved method can be fitted into existing plumbing and plumbing designs.
[0005] The present invention solves the problem of contact with waste material by using a bidet device that has a spray head having an absorbent and preferably disposable spray head cover at the end of a hose. The incoming water is directly applied to the anus to clean the same with water pressure without direct hand contact with the waste.
SUMMARY OF THE INVENTION
[0006] The invention is directed to a device for anal cleansing with water pressure without direct hand contact with the anus, comprising a mixing valve attached to and regulating hot water provided through a hot water inlet, cold water provided through a cold water inlet and a mixed water outlet, and a hose having a proximal end connected to the mixed water outlet and having a distal end connected to a spray head assembly, said spray head assembly being operable for spraying water to the anus and having an absorbent spray head cover provided thereupon. The invention is also directed to methods for anal cleansing without direct hand contact with the anus using the device or devices of the invention.
[0007] In another embodiment, the invention is directed to a bidet for anal cleansing without direct hand contact with the anus, comprising:
[0008] (a) a hot water source, comprising a hot water source pipe connected to a hot water connector for allowing water to flow to the hot water inlet of the mixing valve described above and to a hot water inlet of a separate bathroom fixture; and
[0009] (b) a cold water source, comprising a cold water source pipe connected to a cold water connector for allowing water to flow to the cold water inlet of the mixing valve described above and to a cold water inlet of a separate bathroom fixture; and is also directed to use of such a bidet.
BRIEF DESCRIPTION OF THE FIGURES
[0010] Novel features and advantages of the present invention in addition to those noted above will be become apparent to persons of ordinary skill in the art from a reading of the following detailed description in conjunction with the accompanying drawings wherein similar reference characters refer to similar parts and in which:
[0011] FIG. 1 shows a known cleaning system that provides only cold water for cleaning;
[0012] FIG. 2 shows an embodiment of the invention in which a first pipe has a switch, a mixed water outlet and cold and hot water inlets;
[0013] FIG. 3 shows a front elevational view of an embodiment of the invention showing a bidet attached to a mixing valve, and the mixing valve attached to a sink, in which the mixing valve is also shown connected to a commode via a cold water line shown in phantom outline (the elements are not to scale);
[0014] FIG. 4 shows a left side elevational view of the mixing valve shown in FIG. 3 ;
[0015] FIG. 5 shows a front elevational view of the spray head shown in FIG. 3 ;
[0016] FIG. 6 is an exploded view of the spray head shown in FIG. 4 ; and
[0017] FIG. 7 shows a front elevational view of the spray head shown in FIG. 3 with the retainer nut removed to show how the O-ring secures the spray head cover.
DETAILED DESCRIPTION OF THE INVENTION
[0018] One of the unhealthiest practices in human experience is the process of cleaning the body after restroom use. Hand contact with the waste product has remained an unavoidable process that could raise health issues because of contamination. The health issues are increased mainly because hands are also utilized for eating. Although excessive washing could alleviate the problem, complete success has so far been questionable.
[0019] FIG. 1 shows a known device 10 that may be used for cleaning purposes. Cold water is supplied from a water source through the cold water pipe 12 . The water is released or stopped by a mechanical switch 14 , which lets water flow through the extended hose 16 , which may have a retainer clip 18 for attaching a nozzle 19 to hose 16 . The user typically holds the hose 16 and/or the nozzle in one hand and cleans the waste off the anus by the other hand through direct contact with the waste. By “direct contact” is meant that the hand is involved in holding a tissue, cloth, or other item whose surface is directly applied to the body for contact with waste material.
[0020] The present invention advantageously provides an alternate means of cleaning waste matter from a human anus without direct physical contact with the waste.
[0021] As shown in FIG. 2 , in one embodiment the invention is directed to a device for anal cleansing with water pressure without direct hand contact with the anus, comprising a mixing valve 20 attached to a cold water line 22 at a cold water inlet 24 , and a hot water line 26 at a hot water inlet 27 . Mixing valve 20 is also connected to mixed water outlet 28 in which water mixed to a desired temperature exits the mixing valve. A mechanical switch 14 allows for the control of the flow of the hot and cold water from the inlets 24 and 27 to the outlet 28 . This embodiment provides improved comfort for the user over the prior systems by allowing for temperature adjustment, rather than only providing cold water. In this embodiment, the mixing valve 20 is capable of regulating water temperature in the mixed water outlet 28 by proportional mixing of hot and cold water from the cold water inlet 24 and the hot water inlet 27 . Any known electromechanical or mechanical switch 39 , including, for example, a circular, vertical, horizontal, bent or straight switch may be used for modulating hot and cold water entering the mixing valve 20 and exiting outlet 28 .
[0022] The mixed water outlet 28 may be attached to a hose 30 , as shown in FIG. 2 . Hose 30 is preferably flexible, such as can be accomplished with flexible plastic, polyvinyl chloride, rubber, flexible metal, or other suitable material. Also, hose 30 should be capable of extending some distance from the pipe to allow for use of the hose near the body.
[0023] According to one embodiment, spray head assembly 33 is attached directly or indirectly to a distal end of hose 30 using a retainer clip 31 . The spray head 33 preferably has a structure such as a mechanical switch that allows water spray to be turned on or off by the same hand that is holding spray head 33 to direct the spray of water to the desired location. For example, as shown in FIG. 2 , spray head 33 may be controlled by a conventional lever-operated switch 35 on spray head 33 that releases water when depressed.
[0024] Also, the flexible hose may have a second spray head assembly 37 connected to the distal end of the hose 30 and the spray head assembly 33 . An O-ring or washer 38 between the two spray heads 33 and 37 and/or between the spray head 37 and distal end of hose 30 has been shown to be desirable to avoid leakage. The spray head 37 may be attached to hose 30 by a retainer clip 31 .
[0025] According to an alternative and preferred embodiment, shown in FIGS. 3, 5 and 6 , hose 30 may have a distal end, including a handle 74 , connected directly or indirectly to a spray head assembly 32 . The distal end of hose 30 may be provided with a threaded sleeve 34 designed to engage with a threaded portion 36 of spray assembly 32 . A washer 38 a may be provided between the spray head assembly 32 and the distal end of hose 30 to provide a waterproof connection.
[0026] The exploded view shown in FIG. 6 more particularly shows the configuration of a spray head assembly 32 that comprises a nozzle 42 , spray head cover 44 , retainer O-ring 46 and a threaded retainer nut 48 . As shown also in FIG. 7 , cover 44 may be placed around nozzle 42 and secured by O-ring 46 , which may engage a reduced collar 43 extending downward from nozzle 42 . The threaded retainer nut 48 has threads 70 that engage with threaded portion 72 of nozzle 42 .
[0027] Other methods may be used as means for securing the spray head cover 44 to the nozzle 42 . For example, a clip may be used to hold the spray head cover 44 on the nozzle 42 at the reduced collar 43 . Suitable clips may be made of a resilient material such as metal or plastic or operate by depression and release of a resilient spring and preferably allow for release of the clip by pinching two clip levers with the fingers of one hand for easy release. In this embodiment, the cover 44 is attached to the nozzle 42 by the clip and thus is released when the clip is released from the nozzle 42 without requiring contact of the hands with the cover 44 . Preferably, the means for holding the cover 44 on the nozzle 42 is such that it provides for secure holding under the pressure washing conditions yet allows for easy release, preferably with one hand, after washing and requires no hand contact between the user and the cover 44 .
[0028] One end of the nozzle 42 is provided with one or more holes 50 to allow water to exit. The hole(s) 50 may be of any size, but decreasing the size and number of holes increases the fluid pressure that can be achieved. If multiple holes are used, they can be arranged in any suitable manner to optimize the fluid pressure and the surface area being cleaned. For example, placing multiple holes 50 along the spray head may increase the effective washing area and thereby clean a larger surface in a shorter period of time. In one embodiment, the nozzle is of a spherical shape and has a diameter of 1 1/16 inches. Preferably, the nozzle is spherical and has a diameter between 0.5 and 2.5 inches, more preferably between 1.0 and 2.0 inches, and still more preferably between 1.0 and 1.5 inches, inclusive.
[0029] The spray head 32 , 33 , and/or 37 may be metal, plastic, or other suitable material. The spray head cover 44 may be comprised of any conventional material that allows for water under pressure to pass through. Preferably, spray head cover 44 may be made of an absorbent material and be disposable, such as by being made of cloth, which may have a high cotton content; sponge; foamed polymer or plastic; threaded fiber; or other suitable material. The term “disposable” is used herein to describe articles that generally are not intended to be laundered or otherwise restored or reused (i.e., they are intended to be discarded after a single use or after a very few uses by only one individual).
[0030] Spray head assemblies 32 , 33 , and/or 37 may assist in removing waste through water pressure. Spray head assembly 32 may also remove waste through scrubbing contact of the cover 44 and the area to be cleansed. In alternative embodiments, the spray head assemblies 33 and 37 may be altered to cover the nozzles with an absorbent and preferably disposable cover of the type discussed herein with regard the spray head assembly 32 .
[0031] The embodiment of the cleansing device that utilizes spray head 32 will now be described in more detail with reference to FIG. 3 . Mixing valve 20 is contained within valve housing 40 , which is attached to or integral with a flange 41 . As shown in FIG. 4 , the flange 41 may be attached directly to a wall or other substrate. Furthermore, the mixing valve may be connected to a mechanical switch or handle 39 for adjusting the flow of hot and cold water. Valve housing 40 may be sized to fit on a bathroom wall between a commode 62 and a sink 60 , under a sink 60 , or so that the mixing valve 20 can easily fit near any conventional water source, such as sink 60 , even if there is little available space. Preferably valve housing 40 is located near a commode, wash basin, shower stall, or other suitable area for ease of use and to allow the water to drain.
[0032] As shown in FIG. 3 , spray head assembly 32 may be placed or hung in a cradle 42 or other suitable means that may be mounted to a wall or other substrate. Using this or a similar configuration, the spray head assembly 32 can be releasably maintained within reach of a user and/or proximate to the valve housing 40 . Hanging the spray head 32 in an upright position, as shown in FIG. 3 , may have the additional benefit of reducing or eliminating any water from exiting the spray head 32 after the mixing valve 20 is closed.
[0033] The cleansing device, which may include the mixing valve 20 , hose 30 , and spray head 32 as described above, may be connected to existing water lines to retro-fit existing plumbing, such as that which may be found in a typical bathroom. To accomplish this task, a conventional water connector 52 a,b,c may be connected so that a given source of water, such as cold water source pipe 56 a or hot water source pipe 56 b , can service the original fixture as well as the cleansing device. For example, for a given cold water source pipe 56 a , connector 52 a may be T-shaped and can be added between water source pipe 56 a and the existing fixture inlet pipe 58 a so that water also flows to cold water line 22 . The hot water source pipe 56 b could be similarly attached to the cleansing device's hot water inlet 26 and the fixture inlet pipe 58 b . In FIG. 3 , the existing fixture is represented as a sink 60 . Alternatively or additionally, the fixture could be a shower (not shown).
[0034] The cold water line 22 could also alternatively be connected to the commode water source 56 c , rather than to sink water source 56 b . As shown in phantom outline, the cold water line, which is designated as 22 cc for clarity, of the cleansing device could be connected to water source 56 c by a connector 52 c . Connector 52 c may also allow water to flow to inlet pipe 58 c of the commode tank 62 . 3 The connectors 52 a,b,c may be formed of any conventional shape to accommodate the locations and orientations of the plumbing and may be formed of any conventional materials such as metal or plastic. The connectors 52 a,b,c may have one water inlet, two water outlets, and may comprise a conventional mechanical valve to regulate or restrict water flow to the outlets. Of course, the various water lines could be reversed, such that the hot and cold water flows through the opposite pipes described above, without diverting from the present invention.
[0035] Other variations of the embodiments described above are envisioned. For example, the nozzle 42 or the handle 74 on the hose 30 may include a shut-off valve, which is not shown in the figures. Such a valve may operate by means of a lever or button that is normally biased to the closed position for shutting off the flow through the nozzle. The lever or button can be operated by squeezing the lever or pushing and holding the button with one hand and thereby opening the cut-off valve to allow water to flow through the nozzle. In this manner, on/off control of the water flow can be maintained by the hand holding the handle of the hose. Such a shut-off valve at the nozzle or handle of the hose would be in addition to the mixing valve 20 that also controls flow of water to the nozzle. In this embodiment, a second flow control would be located such that it could be operated by the hand holding the hose and thereby provide for simplified control of the water flow.
[0036] Clearly, the invention is not limited to the examples provided herein, such as the examples embodied in the FIGS. 2-7 . In fact, a combination of different pipes as shown in FIG. 3 can also be assembled for the same purpose. The direction of the inlet and outlets on the pipes may be adjusted to fit the architecture. The separation between the two pipes in a given assembly is variable. The hot water source pipe 56 a and the cold water source pipe 56 a , or 56 c , may be between a few inches apart to 3 feet apart depending on the application; the method provides flexibility in installation because these two pipes are not in a fixed relationship to each other. Thus, the bidet embodiments can be retro-fitted into an existing bathroom easily. It is possible for the hot water and cold water mechanical switches to be mounted on the wall, such as in a box.
[0037] The products of the invention allow a user to clean the anus without hand contact. By this is meant that either the water pressure from the spray alone or the water pressure from the spray head in coordination with contact with an absorbent spray head cover is sufficient to remove most or all of the waste without requiring any hand wiping. Such avoidance of hand use allows a user to achieve proper cleansing without risking contamination of the user's hands. | The invention relates to a device for anal cleansing comprising a mixing valve attached to a hot water inlet, a cold water inlet and an outlet for the mixed water; and a hose having a proximal end connected to the mixed water outlet and having a distal end connected to a spray head assembly, said spray head assembly being operable for spraying water to the anus and having an absorbent spray head cover provided thereupon. | 4 |
RELATED APPLICATIONS
[0001] This application is a continuation of prior U.S. Ser. No. 08/929,883, filed Sep. 15, 1997, which is a continuation-in-part of prior U.S. Ser. No. 08/165,331 filed Dec. 10, 1993, now U.S. Pat. No. 5,668,824, which is a continuation-in-part of prior U.S. Ser. No. 08/098,467, filed Jul. 28, 1993, now abandoned, the contents of which are incorporated herein by reference.
BACKGROUND
[0002] Dye lasers excited with flashlamp were first discovered by Sorokin and Lankard in 1967. These flashlamp excited dye lasers have found use in many applications. The dye, which is the laser medium, is dissolved in a solvent, most usually of organic nature. The laser medium, being a solution, makes the flashlamp excited dye laser a liquid laser. The dye solution is circulated through a laser pump cavity by means of a capillary dye cell, the axis of which in most instances coincides with the laser axis. The dye cell is activated or excited by a flashlamp which is in close proximity to it. The ends of the capillary dye cell are terminated with laser windows through which the laser beam can be extracted.
[0003] The dye solution, comprised of the laser dye or dyes and organic solvent and which may include other chemical additives, undergoes photochemical changes induced by the flashlamp light. The photochemical action may result in the destruction of dye molecules and generation of by-products that absorb at the lasing wavelength and that reduce the gain of the laser for subsequent excitation pulses. To minimize the contribution of these deleterious reactions, a large reservoir of dye solution can be used to minimize the proportion of degraded dye solution. However, the deleterious by- products accumulate and, in time, the overall dye solution will degrade as the laser is used.
[0004] To overcome this problem, many different types of dye circulation systems have been devised either to minimize the generation of deleterious by-products, or to remove the deleterious by-products by means of filtering systems.
[0005] An ideal approach to keep the dye solution from degrading under use is to identify a filter that selectively removes the contaminant that degrades the laser output. A generic concept of such a circulation system was disclosed as U.S. Pat. No. 4,364,015 by Drake et al. Although the patent describes the circulation system in a generic manner, the exact nature of the selective filter that removes degradation by-products is not described; nor has such a filter been discovered that can universally be used with all dye laser solutions. Mostovnikov describes a filter that appears to have the properties of a selective filter (V. A. Mostovnikov et al., “Recovery of lasing properties of dye solutions after their photolysis, American Institute of Physics, Sov. J. Quantum Electron, Vol. 6, No. 9, September 1976). Attempts to duplicate his approach in commercial dye lasers that require repetitive operation of tens of thousands of pulses have been unsuccessful.
[0006] It is unlikely that a universal selective filter can be discovered because there are infinite combinations of dyes, solvents, and additives used in dye lasers. The filter described in U.S. Pat. No. 4,364,015 to remove dye solute is identified as a charcoal bed filter. Charcoal is effective in removing most dye solutes used in flashlamp excited dye lasers. Charcoal bed filters have also been shown to be selective in removing deleterious by-products generated in dye laser solutions.
[0007] Another complication that arises in finding filters that remove dye solute or degradation products is the rate of degradation of the dye solution. Certain dye solutions degrade slowly and the degradation by-products contributed by each excitation pulse is low. Dye solution life is long, and simple degradation compensation schemes, such as increasing the excitation pulse to compensate for loss in gain produced by the degradation products, can be used. In other cases, the solution volume irradiated by the excitation pulse is so full of degraded by-products that it is best to discard the irradiated volume than send the irradiated volume back to the reservoir where it can contaminate the solution in the reservoir. A dye circulation system that extracts the excited and degraded solution in a single shot is described in U.S. Pat. No. 4,977,571 to Furumoto et al.
[0008] If a rapidly degrading dye solution is used with a dye circulation system described in U.S. Pat. No. 4,364,015, the flow in the cleaning loop must be increased to keep up with the degradation. The system will work but the flow in the bypass cleaning loop will increase to be equal to, or greater than, that in the loop that contains the laser head. If the flow in the cleaning loop is large, the metering pump must add a considerable amount of dye concentrate to keep the dye concentration at the optimum level. It has been known for some time that in a situation where the dye solution flow through the cleaning loop is large and the dye solute added is large, or if concentrate is added continuously without replacing the filter, the solute removing filter will begin to load up with dye solute and not be able to remove all of the dye solute coming into the filter. However, it was noted that the filter, if it is a charcoal filter, has the property of removing degradation by-products that reduced the gain of the laser as well as dye solute, even if it passed dye solute. The above observations were also noted by Garden et al. and presented in U.S. Pat. No. 5,109,387. That patent describes the filter as being saturated with dye solute and the dye solution is regenerated by the filter.
SUMMARY OF THE INVENTION
[0009] Experiments with charcoal bed filters indicate that filters do not saturate with dye but continually absorb dye solute, though at a diminishing rate, and the dye solute concentration in solution does not come into equilibrium to maintain a constant concentration. The filter does not continually regenerate the dye solution and, in fact, experiments show that dye and additives must be added as the filter is used.
[0010] The present invention relates to a method of replenishing dye solution in a dye laser. Prior to operation of the dye laser, a solid state porous system with restricted geometries is loaded with solute to act as a repository of dye solute. Specifically, solution at a predetermined operating dye solute concentration flowing into the porous bed filter, PBF, repository remains at substantially the same concentration. With firing of the laser, the PBF serves the necessary function of filtering out undesirable by-products of the lasing process. However, since it was preloaded, only minimal amounts of dye solute are filtered out. Solute concentration in the dye solution, which may include dye solute concentration and additive solute concentration, is monitored, and solutes are replenished as required in response to changes in the monitored solute concentration. Preferably, only dye concentration is monitored, but both dye solute and additive solute, such as cyclooctatetraene (COT), can be added together.
[0011] Since the filtering action of the PBF is very temperature dependent, temperature of the dye solution is monitored and controlled, preferably within ±2.5° C. With the solute metering and close temperature control, color output of the laser is very stable and solute concentration can be closely controlled to maximize color output at the wavelength selected by the optical color regulator often found on dye lasers.
[0012] Preferably, dye solute concentration is monitored by monitoring optical absorption of the solution. In a preferred embodiment, light is directed from a light source through a first filter and through dye solution to a detector in a first channel and from the same light source through a second filter to a detector in a second channel. The monitor filters have a passband at a characteristic absorption wavelength of the dye solution and, unlike a spectrophotometer, reject broadband fluorescence of the dye solution. The outputs to the two channels are compared to provide the indication of dye concentration. The sensitivity of the two channels may be adjusted so that they yield the same signal strength when the concentration of the solute in solution is the desired operating concentration. A difference signal between the two channels may be digitized and loaded into an electronic counter with a solute metering pump being driven by the counter.
[0013] The monitoring and replenishing steps need not be performed continuously but may be performed after some predetermined number of firings of the laser. The number of firings may be adjustable to match solute degradation rate.
[0014] The solute concentration balance between the filter and the solution is highly temperature sensitive. Preferably, a temperature sensor is located in the circulation loop to monitor the temperature, and a temperature controller is used to control a heater and a cooling device to control the dye solution temperature.
[0015] The number of laser pulses that can be elicited from the dye solutions can be notably increased by maintaining the solution at a designated or preselected pH value. This pH maintenance is accomplished by adding one or more pH buffer substances to the solution. The addition of such buffers to the dye solution provides enhanced lasing process life to these solutions.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention.
[0017] [0017]FIG. 1 is a schematic illustration of the optical portion of a dye laser system embodying the present invention.
[0018] [0018]FIG. 2 is a schematic illustration of the dye handling portion of a dye laser system embodying the present invention.
[0019] [0019]FIG. 3 is an electrical schematic of the solute concentration monitor and metering pump controller of FIG. 2.
[0020] [0020]FIG. 4 is a plot of laser energy output relative to solution temperature for a given dye solution.
[0021] [0021]FIG. 5 is a plot of laser output wavelength against temperature for a given dye solution when a color regulator is not used.
[0022] [0022]FIG. 6 is a schematic illustration of an alternative embodiment of the dye circulation portion of a dye laser system of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0023] [0023]FIG. 1 is an optical schematic of a laser system embodying the present invention. The laser cavity is a dye cell 20 through which a dye solution flows from an input 22 to an output 24 . The dye solution is typically energized by a flash of light from a flashlamp (not shown) which causes the dye in the solution to lase. Light emitted from the back end of the dye cell is reflected back into the cell by a reflector 26 ; whereas, light emitted from the front end of the dye cell is only partially reflected by a reflector 28 . Light not reflected by reflector 28 is the laser beam output from the system. A preferred application of the present invention is in a photothermolysis system. In that system the laser output is coupled through an optical coupler 30 to an optical fiber 32 through which it is directed to a hand held wand 35 for treatment of a patient's skin.
[0024] A color regulator 36 is interposed between the dye cell 20 and the reflector 28 . Typical intercavity laser tuners that can be used are interference filters, etalons, prisms, birefringent filters and gratings. Such regulators are typically found in systems to tune the color of the laser output and thus maintain a preset color despite changes in the dye solution. With the present invention, the requirement for such fine tuning is minimal, so the output at the preset wavelength can be maximized.
[0025] The color at which the laser output is most efficient is set principally by the dyes used in the dye solution, or by the ratio of two or more dyes in the solution if multiple dye solutes are used. The concentrations of the dyes are also established to establish energy output of the laser. In addition to the dyes in one or more solvents, the dye solution includes one or more additives such as triplet quenchers, e.g. cyclooctatetraene (COT), and solublizers. The solublizers assist in keeping high concentrations of solute in solution and may include dimethyl formamide, propanol carbonate, methanol, ethanol or isopropanol.
[0026] With each firing of the laser, one or more of the solutes in the solution may degrade. Of particular note is the degradation of COT, which was included to quench the triplet state of the dye in long pulse lasers such as those used in photothermolysis. COT degrades rapidly into by-products which must then be removed from the solution to avoid degradation of the laser output, and the COT must be replenished. Unfortunately, the filter employed, typically a charcoal bed filter, not only removes the COT by-products but also other solutes such as dye. Accordingly, to maintain proper operation of the laser over cycles in the order of tens of thousands, the dye must be replenished as well.
[0027] Another means to increase the useful life of the laser dye solutions is by maintaining these solutions at a proper pH value. This value can be determined empirically by ascertaining the number of laser pulses of useful quality that can be produced from a given quantity of laser dye in solution at a predetermined pH. The pH of the dye solution can be established and maintained by adding a suitable acid or base to the solution but, preferably, the pH is established and maintained by adding one or more pH buffer materials to the solution. Suitable buffers can be either organic or inorganic in nature. Examples of organic buffers include TRIS, MES and TES (Good's buffers). Examples of inorganic buffers include sodium phosphate, potassium phosphate and sodium bicarbonate. Mixtures of these buffer materials can be used if desired. The optimum pH will depend on the choice of solvent and solutes used. Once the optimum pH is determined, it can be maintained with the chosen buffers.
[0028] In a preferred embodiment of the present invention, the pH is maintained at a neutral to somewhat basic pH value, i.e. between pH 7.0 and pH 8.0. A particularly preferred pH value is pH 7.6 for the rhodamine dye laser solutions. This pH value can be adequately maintained with a mixture of KH 2 PO 4 and Na 2 HPO 4 .
[0029] [0029]FIG. 2 illustrates a dye circulation system embodying the present invention for assuring uniform color and energy output from the dye laser with multiple pulses of the laser. As in a conventional system, a dye solution is pumped from a main reservoir 34 by a main pump 41 through a particle and bubble filter 38 and the dye cell 20 of laser 18 . The laser is controlled by regulator 39 which controls color tuning through the optical color regulator 37 and laser excitation energy.
[0030] In accordance with the present invention, a filter 40 such as a charcoal bed filter is provided in a filter loop for filtering out degraded solute and by-products of the laser operation. To replenish dye and additive such as COT, metering pump 42 delivers dye and additive concentrate from reservoir 46 into the filter bypass loop 50 . Loop 50 returns the filtered and replenished dye solution to the main reservoir 34 .
[0031] To control the metering process, a solute concentration monitor 52 is provided. That concentration monitor may take a number of forms, including optical or electrical sensors, but is preferably an optical monitor which senses light absorption at a wavelength corresponding to a signature of the dye solute or solutes as discussed below. A metering pump controller 48 controls the pump 42 in response to the monitored dye concentration. Although illustrated as being in a separate bypass loop, the filter and metering pump may be coupled into the main laser loop.
[0032] The filter 40 is required principally to filter out the by-products of the lasing process such as by-products of COT degeneration. Unfortunately, the filter also removes still effective dye solute. In the past, the filter has been allowed to load with dye during operation of the laser until it approaches a balanced state with the circulating solution wherein only small amounts of dye are removed by the filter. Thereafter the filter continues to be effective in removing the undesirable by-products.
[0033] In accordance with the present invention, the filter 40 is preloaded by circulating the dye solution through the filter for a period of time prior to firing of the laser. The filter may be preloaded at the factory to minimize the required size of the reservoir 46 , or it may be preloaded from the reservoir 46 by cycling dye solution through the system while adding solute. In this way, with firing of the laser, the system does not first go through a period in which a large amount of dye is removed by the filter followed by a period during which only small amounts of dye are removed. With this system, small amounts of dye are consistently removed by the filter 40 and can be readily replenished with small amounts of dye concentrate delivered through the metering pump 42 .
[0034] In a typical system, pump 41 pumps at about four gallons per minute. One fourth of the flow is to the laser cell while three fourths of the flow is through the filter 40 . The dye concentrate in reservoir 46 would be 0.5 mole of dye in 100 liters of solvent, and the additive concentrate would be 0.3 mole of COT in 10 3 liters of solvent. Since close control of dye concentration is much more critical than that of COT, the preferred system only monitors dye concentration and meters both dye solute and COT in response to the dye concentration. As an alternative, separate reservoirs and meter pumps may be provided for the dye and additive. In such a system, the dye and additive may be separately monitored for more precise metering of each.
[0035] A preferred example of a PBF repository is a carbon bed filter, particularly a charcoal bed filter. The large surface area of activated charcoal and numerous pores allow dye and additive molecules to remain in residence within its structure. The solvent too is held within this structure and a solute-solvent balance is obtained with the solution. Other filters which may serve the purpose include vycor glass, alumina, silica gel, zeolite, and molecular absorption filters.
[0036] If a PBF repository system is included in a circulation system of a dye laser, the volume of solution can be reduced dramatically because the PBF repository can keep enormous amounts of dye and additives and still maintain the solution concentration at a useful level. The charcoal bed filter has another great advantage in that it can remove degradation products that lower the efficiency of the dye laser.
[0037] In the more complex dye solutions used in dye lasers, the solution may contain one or more dyes, one or more additives, solublizers and one or more solvents. The formulation will depend on the concentration of each species and therefore, the combination, can be infinite. The color and energy level outputs of such systems change over multiple laser pulses and are also temperature dependent.
[0038] The problem of temperature dependency becomes more complex if solutes and additives are stored in porous bed filters. The surface area of a carbon or charcoal bed filter can be as much as 1,000 square meters per gram of carbon. Water molecules may have a cross sectional area of 10 square angstroms, ethylene glycol 25 square angstroms, and dye molecules perhaps 150 square angstroms. Each has a different activation energy in the porous bed filter. The partition function at the solid-liquid interface is extremely complex. Moreover, the access to the inner pores is slow and transport limited by diffusion. Equilibrium is reached asymptotically and experiments show that equilibrium by diffusion may take days or weeks to be reached. Temperature, however, strongly affects the partition function and temperature effects overshadow diffusion processes.
[0039] [0039]FIG. 4 shows how the energy output of a dye laser containing a PBF repository changes as a function of temperature for a selected filter and solvent, dye solute and additive combination. The maximum laser output should not be considered as absolutely corresponding to a temperature of 40 C and higher. Another PBF repository with a different solvent, solute and/or additive may give maximum laser output at another temperature. The curve is similar to a curve used to optimize the output of a dye laser by varying the concentration(s) in a standard circulation system. The change in temperature changes the concentration of dye solute and additive in solution. In FIG. 4, the concentration at 40 C is such that there is a maximum output. As the temperature is raised, more dye solute and additives are driven out of the reservoir and into the solution.
[0040] [0040]FIG. 5 shows the color change of the dye laser containing the PBF repository described above. The color change again is not the direct result of a change in temperature, but more likely is due to the change in solute concentration. The dye solute, additive and solvent combination must be adjusted to give maximum output at the correct color at a chosen operating temperature. With experience, the choice from an infinite number of combinations can be reduced to a few combinations that are optimum or near optimum.
[0041] But the combination is only energy output optimum at some chosen temperature, and the color is such a strong function of temperature that it is important to thermostat the operating temperature. For treatment of vascular lesions using the principle of selective photothermolysis, it is important to keep the color variation to within ±2 nm and since the slope of the color versus temperature curve is linear at 0.8 nm/C, it is important that the system be controlled at ±2.5 C.
[0042] As illustrated in FIG. 2, the circulation system further includes a temperature sensor 54 , preferably located in the main reservoir 34 . A temperature controller 56 responds to the sensed temperature to control a heater 58 and/or liquid cooling heat exchanger 60 in the main circulation loop.
[0043] Good temperature regulation can be obtained by one of many available thermostats based on thermocouples, thermistors, liquid thermometers, and gas expansion bulbs. However, a good, accurate and nearly absolute thermometer can be derived using an integrated circuit temperature transducer such as AD592 by Analog Devices. They are convenient because in addition to having good sensitivity and range with a temperature coefficient in the order of microvolts/K, the output voltage is an absolute function of temperature, and therefore a comparison temperature calibration feature is not needed.
[0044] In the past, cooling systems have been used to counter the heating caused by the laser firing process, and such cooling heat exchangers have typically kept the dye solution at about room temperature. It has been determined, however, that so long as the dye solution has been properly specified for operation at higher temperatures, the actual temperature to which the solution is held is not critical. Thus, to minimize cooling required by the system, the present system preferably runs at about 38-40° C. To maintain consistent color output, that temperature is maintained within 2.5° C. and preferably within ±1° C. This higher temperature also provides the added advantage of requiring less dye in the system since at higher temperatures the filter removes less dye.
[0045] As discussed above, the concentration of specific solutes (dye or additive) is monitored at 52 by means of optical absorption at a specific wavelength. As illustrated in FIG. 3, the solution being monitored is allowed to flow through a sensing cell 62 . The solution is illuminated from one side by a pulsed source 64 of white light. An optical interference filter 66 on the opposite side of the sensing cell selects a specific, narrow range of wavelengths, with the center wavelength of the filter corresponding to a signature of the solute or solutes to be monitored. A photodiode 68 detects the light transmitted through the filter, and produces an electronic signal proportional to the amount of light reaching the photodiode.
[0046] A second, “reference” photodiode 70 also views the light source 64 through an identical optical interference filter 72 , but without the intervening solvent. The sensitivity of the two detection channels (designated “sample” and “reference”) are adjusted so that they yield the same electronic signal strengths when the concentration of the solute in solution is optimum for operation of the laser. As the concentration of the specific solute of interest decreases below the optimum value, the solution absorbs progressively less light at the selected wavelength, and the signal strength produced by the sample photodiode therefore increases relative to that of the reference photodiode.
[0047] The metering pump controller electronically subtracts the sample channel signal from the reference channel signal at comparator 74 producing a difference signal which increases in amplitude as the solute concentration decreases. The difference signal is used to control the injection of new solute in order to bring the solution back to optimum. New solute is injected in the form of a highly concentrated solution (“concentrate”), by means of an electrically actuated metering pump 42 . Each actuation of the pump results in the injection of a known volume of concentrate into the laser dye solution. The number of pump actuations is derived directly from the difference signal by digitizing it in analog to digital converter 76 and loading the result into a counter 78 which in turn determines the number of metering pump actuations. In this way, the correct amount of concentrate is added each time the metering pump controller is operated.
[0048] The metering pump controller operates at discrete intervals. At the start of the operating sequence, the metering pump controller causes the light source in the solute concentration monitor to pulse. The metering pump controller then detects the resulting electrical signal from the reference photodiode 70 . The controller digitizes the difference signal (reference minus sample), loads the result into the electronic counter 78 , and actuates the metering pump 42 based on the counter contents. The sequence repeats periodically, based on the accumulated number of laser pulses since the last sequence. The number of pulses which elapse between operations may be adjusted thus allowing the system to be tailored to the specific requirements of any particular dye laser.
[0049] The following example illustrates that the pH of the laser dye solution has a notable effect on the number of laser pulses which can be generated from a given quantity of the solution:
[0050] A long pulse dye laser with a dye circulation system as configured in FIG. 6 was tested with two dye formulations. The structural features in FIG. 6 are the same as those in FIG. 2 and therefore retain the same designation numbers. However, in this embodiment the dye concentrate is metered into the system before the filter to provide more stable control of the concentration through the laser. The temperature control system would also be included in the most preferred embodiment.
[0051] One dye formulation was:
Rhodamine 560 4.4 gms Rhodamine 590 5.76 gms Ethylene Glycol 3.2 liters H 2 O 3.2 liters Cyclooctatetraene 9 ml KH 2 PO 4 7.6 gm Na 2 HPO 4 28 gm Activated Carbon Filter 3″ dia × 10″ Fluid Solutions C231 pH 7.6
[0052] The other dye formulation was identical to the immediately preceding one with the exception that the KH 2 PO 4 and Na 2 HPO 4 substances were not present. The pH of this formulation was 3.5. The Rhodamine dyes were supplied by Exciton Chemical Corporation. Each alone lases at a wavelength of 560 and 590 nanometers, respectively, but the combination lases at about 585 nanometers.
[0053] The dye concentration monitor was set to inject concentrate below absorbance of 0.4 at 530 nm. The dye concentrate was a solution with 0.015 molar R560 and 0.02 molar R590 in ethylene glycol. The laser output was fixed at 2.5 J and a feedback system increased the voltage on the the capacitor bank to maintain constant output as the dye solution degraded. The voltage range was 4 KV to 6 KV. When the voltage reached 6 KV as the dye solution degraded, the system shut down and a warning was given.
[0054] The results with these laser dye solutions were:
No. of Laser Pulses at 1 Hz pH of Solution Before System Shut Down 3.5 3,000-5,000 7.6 greater than 100,000
[0055] The amount of concentrate injected during the pulsing period for both solutions was 250 ml.
[0056] These results show that maintaining the pH at 7.6 results in more than an order of magnitude more pulses from the dye solution before shutdown when compared to the dye solution without pH buffer. Thus, a given quantity of dye solution at pH 7.6 has at least 10x more usable pulse life.
[0057] Other rhodamine dyes can be used in the laser dye solutions, either alone or in combination with additional laser dyes. For example, rhodamine 575 or its derivatives can be used as the sole laser dye species in the laser dye solution. Alternatively, rhodamine 575 or its derivatives can be used in combination with rhodamine 590 as a laser dye solution mixture.
[0058] While this invention has been particularly shown and described with references to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. | In a dye laser system, a porous bed filter is loaded with dye prior to operation of the system. With repeated firings, the dye solution is filtered by the porous bed filter to remove by-products of the laser process. Solute concentration is monitored and dye and additives removed by the filter are replenished by a metering pump. Precise temperature control assures consistent filtering of dye by the filter for more consistent color and energy output. To control the metering pump, the differential output of a two- channel absorption detector is digitized. The digitized signal is loaded into a counter which drives the metering pump. The useful lifetime of the dye solution is enhanced by incorporating pH buffers in the solution. | 7 |
[0001] The present application claims priority to Japanese Patent Application JP 2008-321652 filed in the Japanese Patent Office on Dec. 17, 2008, the entire content of which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to a liquid crystal display panel having a pixel structure meeting both an analog display mode and a memory display mode. The invention further relates to an electronic device mounted with the liquid crystal display panel.
[0004] 2. Description of the Related Art
[0005] Recently, some liquid crystal display panel may meet both of display in an analog display mode and display in a memory display mode (for example, see Japanese Patent Application Unexamined Publication No. H09-243995). The analog display mode means a display mode in which a pixel gray-scale may be analogously expressed with multiple gray-scales in a minimum display unit (called “sub pixel” in the specification). The memory display mode means a display mode in which a pixel gray-scale may be expressed with two gray-scales of white and black based on binary information (H level or L level) stored in a memory.
[0006] In the memory display mode, operation of writing gray-scale potential need not be performed with a frame period. Therefore, power consumption can be reduced in the memory display mode compared with in the analog display mode.
SUMMARY OF THE INVENTION
[0007] FIGS. 1 and 2 show pixel circuit examples of a liquid crystal display panel meeting both the analog display mode and the memory display mode, respectively. The pixel circuits of FIGS. 1 and 2 show a case where SRAM is used for a memory within a sub pixel respectively. FIG. 1 shows a pixel circuit example when one SRAM is disposed for one sub pixel. FIG. 2 shows a pixel circuit example when one SRAM is disposed for three sub pixels.
[0008] In FIG. 1 , LC shows a liquid crystal corresponding to the sub pixel. However, in FIG. 2 , LC is omitted to be shown for convenience of drawing.
[0009] In FIG. 1 , Cs is a holding capacitance holding gray-scale potential. In FIG. 2 , three holding capacitances are shown as Cs(B), Cs(G) and Cs(R). B in the parenthesis shows a holding capacitance used for a sub pixel corresponding to blue. G in the parenthesis shows a holding capacitance used for a sub pixel corresponding to green. R in the parenthesis shows a holding capacitance used for a sub pixel corresponding to red.
[0010] Each of thin film transistors N 1 , N 1 (B), N 1 (G) and N 1 (R) is an active element that is controlled to be ON during a period of writing gray-scale potential to a corresponding holding capacitance Cs, and controlled to be OFF during other periods. Control lines CTL 1 , CTL 1 (B), CTL 1 (G) and CTL 1 (R) are used for the thin film transistors N 1 , N 1 (B), N 1 (G) and N 1 (R) respectively. In FIG. 2 , ON periods of the thin film transistors N 1 , N 1 (B), N 1 (G) and N 1 (R) are time-sequentially arranged.
[0011] In FIG. 1 , the thin film transistor N 2 is an active element that is controlled to be ON during a period of writing gray-scale potential to corresponding, one sub pixel. In FIG. 2 , the thin film transistor N 2 is an active element that is controlled to be ON during a period of writing gray-scale potential to one of corresponding, three sub pixels. In FIG. 2 , gray-scale potential is finally written to the sub pixel corresponding to blue.
[0012] The thin film transistor N 3 is an active element that is controlled to be ON when gray-scale potential is written in the analog display mode, or when electric potential VXCS different from that of a counter electrode is written in the memory display mode. Holding potential of SRAM (P 1 , P 2 , N 6 and N 7 ) is used for such control. In the case of the circuit example, when the transistor N 3 is ON, the transistor N 4 is OFF, and when the transistor N 3 is OFF, the transistor N 4 is ON.
[0013] The thin film transistor N 4 is an active element that is controlled to be ON when the same potential as that of the counter electrode is written to the holding capacitance in the memory display mode.
[0014] The thin film transistor N 5 is an active element that is controlled to be ON when control potential is written to the SRAM (P 1 , P 2 , N 6 and N 7 ). A control line CTL 2 is used for controlling the thin film transistor N 5 . The thin film transistor N 5 is controlled to be ON or OFF such that the thin film transistor N 3 may be controlled to be ON when gray-scale potential is written in the analog display mode, or when electric potential VXCS different from that of the counter electrode is written in the memory display mode.
[0015] Some difficulties still exist in the pixel circuits of FIGS. 1 and 2 . One of the difficulties is a fact that large area is required for forming the SRAM. It is particularly pointed out that when one SRAM is arranged for one sub pixel, transmissive aperture ratio is reduced.
[0016] In addition, when high display resolution is required for a liquid crystal display panel, it is technically difficult to dispose one SRAM within one sub pixel. This leads to a difficulty that the resolution is limited when the circuit configuration of FIG. 1 or 2 is employed.
[0017] It is desirable to provide a liquid crystal display panel having a memory display mode and an electronic device, capable of avoiding reduction in transmissive aperture ratio and achieving high resolution.
[0018] A liquid crystal display panel according to an embodiment of the invention includes: a capacitive element holding pixel potential representing a gray-scale level and provided in each of pixels; a first switch element having a first terminal connected to one electrode of the capacitive element and to a drive electrode in a liquid crystal element, and having a second terminal connected to a signal line, the first switch element being controlled to be ON during a first operation period where pixel potential is written from the signal line to the capacitive element, and controlled to be OFF during a second operation period where readout of the pixel potential from the capacitive element, inversion and amplification of the read out pixel potential, and rewriting of the inverted-amplified pixel potential to the capacitive element are sequentially performed; a second switch element having a first terminal connected to a first terminal of the first switch element, the second switch element being controlled to be OFF during the first operation period, and controlled to be ON during a readout period where pixel potential stored in the capacitive element is read out, the readout period being one part of the second operation period; a third switch element having a first terminal connected to the first terminal of the first switch element, the third switch element being controlled to be OFF during the first operation period, and controlled to be ON during a write period where the pixel potential is written into the capacitive element, the write period being another part of the second operation period; and a circuit restoring a logic level of pixel potential read out from the capacitive element through the second switch element during the readout period, and then writing logically-inverted output having the restored logic level to the capacitive element through the third switch element during the write period.
[0019] An electronic device according to an embodiment of the invention includes the liquid crystal display panel described above.
[0020] In the liquid crystal display panel and the electronic device according to the embodiments of the invention, the second switch element and the third switch element are controlled to be OFF during the first operation period, and the pixel potential of the signal line is written to the capacitive element at the timing when the first switch element is controlled to be ON. On the other hand, the first switch element is controlled to be OFF, and in this state, the second switch element is controlled to be ON and the third switch element is controlled to be OFF during the second operation period. Thereby, the pixel potential held by the capacitive element is read by the circuit, and a logic level of the read pixel potential is restored. That is, a self-refresh function is performed. Then, the second switch element is controlled to be OFF, and the third switch element is controlled to be ON. Thereby, the logically-inverted output of the restored logic level is written by the circuit to the capacitive element through the third switch element. That is, a self-inverting function is performed.
[0021] According to the liquid crystal display panel and the electronic device of the embodiments of the invention, the capacitive element in each pixel is used as DRAM and refresh operation is completed within the circuit. Therefore, it is possible to avoid reduction in transmissive aperture ratio and to achieve high resolution. Also, the signal line having a large load capacity need not be charged or discharged during the refresh operation. Therefore, it is possible to reduce power consumption associated with the refresh operation.
[0022] Other and further objects, features and advantages of the invention will appear more fully from the following description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1 is a diagram showing a pixel structure example of a liquid crystal display panel.
[0024] FIG. 2 is a diagram showing a pixel structure example of a liquid crystal display panel.
[0025] FIG. 3 is a diagram showing a pixel structure example of a liquid crystal display panel according to an embodiment of the invention.
[0026] FIG. 4 is a diagram showing an example of outside appearance of a liquid crystal display panel.
[0027] FIG. 5 is a diagram showing a sectional structure example of the liquid crystal display panel.
[0028] FIG. 6 is a diagram showing a system configuration example of the liquid crystal display panel.
[0029] FIG. 7 is a diagram showing an arrangement example of sub pixels.
[0030] FIG. 8 is a diagram showing a configuration example of a pixel circuit according to a first embodiment.
[0031] FIG. 9 is a diagram showing a drive operation example in an analog display mode.
[0032] FIG. 10 is a diagram showing a connection condition within a pixel circuit in the analog display mode.
[0033] FIG. 11 is a diagram showing a general drive operation example in a memory display mode.
[0034] FIG. 12 is a diagram showing a detailed drive operation example in the memory display mode.
[0035] FIG. 13 is a diagram showing a connection condition within a pixel circuit when gray-scale potential is read from a holding capacitance.
[0036] FIG. 14 is a diagram showing a connection condition within a pixel circuit during latch operation.
[0037] FIG. 15 is a diagram showing a connection condition within a pixel circuit in a transient period.
[0038] FIG. 16 is a diagram showing a connection condition within a pixel circuit when gray-scale potential inverted in logic is written to the holding capacitance.
[0039] FIG. 17 is a diagram showing a configuration example of a pixel circuit according to a second embodiment.
[0040] FIG. 18 is a diagram showing a drive operation example in an analog display mode.
[0041] FIG. 19 is a diagram showing a general drive operation example in a memory display mode.
[0042] FIG. 20 is a diagram showing a detailed drive operation example in the memory display mode.
[0043] FIG. 21 is a diagram showing a configuration example of a pixel circuit according to a third embodiment.
[0044] FIG. 22 is a diagram showing a drive operation example in an analog display mode.
[0045] FIG. 23 is a diagram showing a general drive operation example in a memory display mode.
[0046] FIG. 24 is a diagram showing another configuration example of a pixel circuit.
[0047] FIG. 25 is a diagram showing a detailed drive operation example in a memory display mode.
[0048] FIG. 26 is a diagram showing a functional configuration example of an electronic device.
[0049] FIG. 27 is a diagram showing a product example of an electronic device.
[0050] FIGS. 28A and 28B are diagrams showing a product example of the electronic device.
[0051] FIG. 29 is a diagram showing a product example of the electronic device.
[0052] FIGS. 30A and 30B are diagrams showing a product example of the electronic device.
[0053] FIG. 31 is a diagram showing a product example of the electronic device.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0054] Hereinafter, embodiments of the invention will be described with reference to accompanied drawings.
[0055] A liquid crystal display panel according to one embodiment of the invention employs a pixel circuit utilizing a capacitive element holding gray-scale potential as DRAM, and includes the following elements (1) to (5) illustrated in FIG. 3 .
[0056] (1) A capacitive element Cs holding pixel potential representing a gray-scale level and provided in each of pixels.
[0057] (2) A first switch SW 1 having a first terminal connected to one electrode of the capacitive element and to a drive electrode in a liquid crystal element, and having a second terminal connected to a signal line. The first switch is controlled to be ON during a first operation period where pixel potential is written from the signal line to the capacitive element, and controlled to be OFF during a second operation period where readout of the pixel potential from the capacitive element, inversion and amplification of the read out pixel potential, and rewriting of the inverted-amplified pixel potential to the capacitive element are sequentially performed.
[0058] (3) A second switch SW 2 having a first terminal connected to a first terminal of the first switch. The second switch is controlled to be OFF during the first operation period, and controlled to be ON during a readout period where pixel potential stored in the capacitive element is read out. The readout period is one part of the second operation period.
[0059] (4) A third switch SW 3 having a first terminal connected to the first terminal of the first switch element. The third switch is controlled to be OFF during the first operation period, and controlled to be ON during a write period where the pixel potential is written into the capacitive element. The write period is another part of the second operation period.
[0060] (5) A circuit 1 restoring a logic level of pixel potential read out from the capacitive element through the second switch during the readout period, and then writing logically-inverted output having the restored logic level to the capacitive element through the third switch during the write period.
[0061] In the following, embodiments of the invention will be described with reference to FIG. 4 to FIG. 31 . The description will be given in the following order.
(A) Basic Structure of Liquid Crystal Display Panel
(B) First Embodiment: One Circuit 1 Per Sub Pixel
[0062] (B-1) System Configuration Example
[0063] (B-2) Configuration of Pixel Circuit
[0064] (B-3) Drive Operation Example
[0065] (B-4) Conclusion
(C) Second Embodiment: One Circuit 1 Per Three Sub Pixels
[0066] (C-1) Configuration of Pixel Circuit
[0067] (C-2) Drive Operation Example
[0068] (C-3) Conclusion
(D) Third Embodiment: One Circuit 1 Per Six Sub Pixels
[0069] (D-1) Configuration of Pixel Circuit
[0070] (D-2) Drive Operation Example
[0071] (D-3) Conclusion
(E) Other Embodiments
[0072] It will be appreciated that the invention is not limited to embodiments.
(A) Basic Structure of Liquid Crystal Display Panel
(A-1) Outside Structure
[0073] First, an example of outside appearance of a liquid crystal display panel is described. As used herein, the term “liquid crystal display panel” refers not only to a panel module where a pixel array section and a drive circuit are formed using the same process, but also to a panel module where a drive circuit configured as an integrated circuit is mounted on a panel provided with a pixel array section. The integrated circuit here corresponds to “semiconductor device”.
[0074] FIG. 4 shows the example of outside appearance of the liquid crystal display panel. The liquid crystal display panel 11 has a structure where a support substrate 13 is attached with a counter substrate 15 .
[0075] The support substrate 13 includes glass, plastic or another transmissive material. The counter substrate 15 also includes glass, plastic or another transmissive material. The counter substrate 15 is a member sealing a surface of the support substrate 13 with a seal material in between.
[0076] In addition, FPC (Flexible Printed Circuit) 7 is disposed on the liquid crystal display panel 11 for inputting an external signal or drive power as necessary.
(A-2) Sectional Structure
[0077] FIG. 5 shows a sectional structure example of the liquid crystal display panel. The liquid crystal display panel 11 of FIG. 5 includes two glass substrates 13 and 15 , and a liquid crystal layer 19 enclosed in a manner of being sandwiched by the substrates. A polarizing plate 21 is disposed on an outer surface of each substrate, and an alignment film 23 is disposed on an inner surface thereof. The alignment film 23 is used for arranging liquid crystal molecules of the liquid crystal layer 19 in a certain direction. A polyimide film is typically used for the film 23 .
[0078] Pixel electrodes 25 and counter electrodes 27 are formed on the glass substrate 15 , the electrodes 25 and 27 being formed of a transparent conductive film respectively. In FIG. 5 , pixel electrodes 25 have a structure where five electrode branches 25 A formed into a comb shape are connected at either ends via connections.
[0079] In contrast, the counter electrodes 27 are formed on a lower layer side (glass substrate 15 side) with respect to the electrode branches 25 A in a manner of covering the whole pixel area. This electrode structure induces a parabolic electric field between the electrode branches 25 A and the counter electrodes 27 . That is, even regions on tops of the electrode branches 25 A may be affected by the electric field. Therefore, a liquid crystal in the whole pixel area may be directed to a desired orientation direction.
(B) First Embodiment
(B-1) System Configuration Example
[0080] First, description is made on a system configuration of a liquid crystal display panel 31 having a pixel structure according to the present embodiment.
[0081] FIG. 6 shows a system configuration example of the liquid crystal display panel module 31 . The module 31 has a configuration where a pixel array section 33 , a signal line drive section 35 , a control line drive section 37 , and a drive timing generation section 39 are arranged on a lower glass substrate (corresponding to the glass substrate 15 in FIG. 5 ). In the embodiment, a drive circuit of the pixel array section 33 is formed as one or plural semiconductor integrated circuit/circuits, and mounted on the glass substrate.
[0082] The pixel array section 33 has a matrix structure where white units, each unit configuring one pixel of display, are arranged in M rows and N columns. As used herein, the term “row” refers to a pixel line configured of 3*N sub pixels 41 arranged in an X axis direction in the figure. The term “column” refers to a pixel line configured of M sub pixels 41 arranged in a Y axis direction in the figure. Note that a value of M and a value of N are determined according to display resolution in a vertical direction and display resolution in a horizontal direction respectively.
[0083] FIG. 7 shows an arrangement example of the sub pixels 41 configuring white units. The example of FIG. 7 is an arrangement example when a white unit is configured of sub pixels 41 corresponding to three primary colors. Note that a configuration of a white unit is not limited to this.
[0084] The signal line drive section 35 is a circuit driving signal lines DTL. In the present embodiment, the signal lines DTL are wired extending in the Y axis direction in the figure. For example, in the analog display mode, the signal line drive section 35 operates so that optional gray-scale potential (analog potential Vsig) in accordance with pixel gray-scale is applied to a corresponding signal line DTL. For example, even in the memory display mode, when a logic level of gray-scale potential to be stored in a sub pixel 41 is changed, the section 35 operates so that necessary pixel gray-scale is applied to a corresponding signal line DTL.
[0085] The control line drive section 37 is a circuit driving control lines CTL 21 to 25 . In the present embodiment, the control lines CTL 21 to 25 are wired extending in the X axis direction in the figure. For example, in the analog display mode, the section 37 controls operation of writing gray-scale potential applied to a signal line DTL to a sub pixel 41 . For example, in the memory display mode, the section 37 controls refresh operation of gray-scale potential stored in a sub pixel 41 , and rewriting operation.
[0086] The drive timing generation section 39 is a circuit device supplying a drive pulse to the signal line drive section 35 and to the control line drive section 37 .
(B-2) Configuration of Pixel Circuit
[0087] FIG. 8 shows a configuration example of a pixel circuit corresponding to the sub pixel 41 according to the present embodiment. FIG. 8 shows a circuit configuration as a circuit configuration example when the circuit 1 ( FIG. 3 ) having a self-refresh function and a self-inverting function is disposed in one-to-one correspondence to the sub pixel 41 .
[0088] Hereinafter, each of elements configuring the pixel circuit is described.
[0089] In FIG. 8 , LC shows a liquid crystal corresponding to the sub pixel 41 .
[0090] In FIG. 8 , “Cs” shows a holding capacitance holding gray-scale potential. In the present embodiment, the holding capacitance Cs is used as DRAM in the memory display mode.
[0091] A thin film transistor N 11 is an active element that is controlled to be ON during writing gray-scale potential to the holding capacitance Cs, and controlled to be OFF during other periods. A control line CTL 21 is used for controlling the thin film transistor N 11 . One main electrode of the transistor N 11 is connected to wiring connected to a pixel electrode, and the other main electrode is connected to one main electrode of a thin film transistor N 12 through wiring.
[0092] The thin film transistor N 12 is an active element that is controlled to be ON when gray-scale potential is written from the signal line DTL. A control line CTL 22 is used for controlling the thin film transistor N 12 . The thin film transistor N 12 corresponds to the first switch SW 1 in FIG. 3 . One main electrode of the transistor N 12 is connected to the signal line DTL, and the other main electrode thereof is connected to the one main electrode of the thin film transistor N 11 through wiring.
[0093] A thin film transistor N 13 is an active element that is controlled to be OFF when pixel potential is written from the signal line to the holding capacitance. The transistor N 13 is controlled to be ON only for a certain period immediately before end of each frame during performing internal refresh operation of the memory display mode. Gray-scale potential held by the holding capacitance Cs acting as DRAM is read by the circuit 1 ( FIG. 3 ) during a period where the thin film transistor N 13 is controlled to be ON. A control line CTL 23 is used for controlling the thin film transistor N 13 . The thin film transistor N 13 corresponds to the second switch SW 2 in FIG. 3 .
[0094] A thin film transistor N 14 is also an active element that is controlled to be OFF when pixel potential is written from the signal line to the holding capacitance. The transistor N 14 is controlled to be ON only for a certain period immediately after start of each frame during performing internal refresh operation of the memory display mode. Gray-scale potential, which has been inverted in logic within the circuit 1 ( FIG. 3 ), is written to the holding capacitance Cs during a period where the thin film transistor N 14 is controlled to be ON. A control line CTL 24 is used for controlling the thin film transistor N 14 . The thin film transistor N 14 corresponds to the third switch SW 3 in FIG. 3 .
[0095] Thin film transistors P 11 , P 12 , N 15 , N 16 and N 17 configure the circuit 1 in FIG. 3 .
[0096] The thin film transistors P 11 and N 15 configure an inverter circuit (amplifier circuit). In addition, the thin film transistors P 12 and N 16 configure an inverter circuit (amplifier circuit). Drive power of the inverter circuits includes high-level power of VDD and low-level power of VSS.
[0097] An input side of the inverter circuit including the thin film transistors P 11 and N 15 is connected to one main electrode of the thin film transistor N 13 . The inverter circuit may input gray-scale potential of the holding capacitance Cs when the transistor N 13 is ON.
[0098] An input side of the inverter circuit including the thin film transistors P 12 and N 16 is connected to one main electrode of the thin film transistor N 14 . The inverter circuit may write gray-scale potential inverted in logic to the holding capacitance Cs when the transistor N 14 is ON.
[0099] An output side of the inverter circuit including the thin film transistors P 11 and N 15 is connected to an input side of the inverter circuit including the thin film transistors P 12 and N 16 . An output side of the inverter circuit including the thin film transistors P 12 and N 16 is connected to the input side of the inverter circuit including the thin film transistors P 11 and N 15 through a thin film transistor N 17 . The thin film transistor N 17 controls operation of the circuit 1 ( FIG. 3 ). A control line CTL 25 is used for controlling the thin film transistor N 17 .
[0100] For example, when the thin film transistor N 17 is ON, the two inverter circuits operate as a latch circuit. When the inverter circuits operate as the latch circuit, a self-refresh function is enabled. That is, operation of restoring a logic level is performed so as to have logic amplitude of VDD to VSS. Logically-inverted output of gray-scale potential read from the holding capacitance Cs is provided on the output side of the inverter circuit including the thin film transistors P 11 and N 15 .
[0101] In addition, for example, when the thin film transistor N 17 is OFF, the two inverter circuits operate as independent amplifier circuits.
(B-3) Drive Operation Example
[0102] Hereinafter, drive operation examples of the pixel circuit configuring the sub pixel 41 are described for each display mode.
(1) Analog Display Mode
[0103] FIG. 9 shows specific control operation of the control line drive section 37 for a certain scan line in the analog display mode. In FIG. 9 , (A) shows a waveform of gray-scale potential applied to the signal line DTL. In the present embodiment, polarity of voltage applied between a pixel electrode and a counter electrode is inverted on a horizontal-period cycle (1H cycle). That is, line inversion drive is performed. Therefore, in (A), the waveform of gray-scale potential applied to the signal line DTL is drawn such that a potential level is inverted on a 1H cycle. High-level potential of the gray-scale potential applied to the signal line DTL is VDD 1 , and low-level potential thereof is VSS. While (A) shows an example of a case of the largest amplitude, a potential level between VDD 1 and VSS is actually used depending on pixel gray-scale.
[0104] In FIG. 9 , (B) shows a drive waveform of each of the control lines CTL 21 and CTL 22 . High-level potential of drive amplitude is VDD 2 , and low-level potential thereof is VSS 2 . As shown in the figure, drive potential is controlled to the high-level potential VDD 2 only at the timing of writing gray-scale potential from the signal line DTL.
[0105] (C) shows a drive waveform of each of the control lines CTL 23 and CTL 24 . High-level potential of drive amplitude is VDD 2 , and low-level potential thereof is VSS 2 . However, the control lines CTL 23 and CTL 24 are continuously controlled at the low-level potential VSS 2 in the analog display mode.
[0106] (D) shows a drive waveform of the control line CTL 25 . High-level potential of drive amplitude is VDD 2 , and low-level potential thereof is VSS 2 . However, the control line CTL 25 is continuously controlled at the high-level potential VDD 2 in the analog display mode.
[0107] FIG. 10 shows a connection condition within a pixel circuit when gray-scale potential is written from the signal line DTL in the analog display mode. A writing path of the gray-scale potential is shown by an arrow.
[0108] In this case, only the thin film transistor N 12 corresponding to the first switch SW 1 is controlled to be ON as shown in FIG. 10 . In contrast, both of the thin film transistor N 13 corresponding to the second switch SW 2 and the thin film transistor N 14 corresponding to the third switch SW 3 are controlled to be OFF over the whole period. That is, a portion of the pixel circuit including the holding capacitance Cs and a pixel electrode is electrically perfectly isolated from the circuit 1 ( FIG. 3 ).
[0109] The thin film transistor N 17 in the circuit 1 is continuously controlled to be ON, and thus continuously operates as a latch circuit.
(2) Memory Display Mode
[0110] The memory display mode includes operation of writing gray-scale potential from the signal line DTL to the holding capacitance Cs, and operation of refreshing gray-scale potential stored in the holding capacitance Cs within a sub pixel. The operation of writing gray-scale potential from the signal line DTL to the holding capacitance Cs is performed, for example, when display contents are changed. When gray-scale potential is written from the signal line DTL to the holding capacitance Cs, operation of the pixel circuit is the same as operation in the analog display mode. Therefore, description of the operation is omitted.
[0111] FIG. 11 shows a content of control operation of the control line drive section 37 in the case of refreshing gray-scale potential stored in the holding capacitance Cs within a sub pixel. FIG. 11 shows a relationship in drive operation in frames.
[0112] In FIG. 11 , (A) shows a drive waveform of the control line CTL 21 . (B) shows a drive waveform of each of the control lines CTL 23 and CTL 24 . The two control lines are applied with high-level potential in a pulsed manner on a one-frame cycle. (C) shows a drive waveform of the control line CTL 25 . The control line CTL 25 is applied with low-level potential in a pulsed manner on a one-frame cycle.
[0113] In FIG. 11 , (D) shows a drive waveform of counter electrode potential VCS. As shown in the figure, high-level potential and low-level potential are alternately outputted on a one-frame cycle.
[0114] (E) shows a waveform of showing change in gray-scale potential (PIX) to be written to the holding capacitance Cs. As shown in the figure, the gray-scale potential (PIX) is alternately changed in order to keep a light emitting state of the sub pixel 41 in the memory display mode.
[0115] In the memory display mode, the control line CTL 22 is continuously controlled at low-level potential.
[0116] Next, drive operation within one frame is described in detail.
[0117] FIG. 12 shows a content of control operation of the control line drive section 37 for a certain scan line in the memory display mode. FIG. 12 shows a boundary portion between frames of FIG. 11 in an expanded manner. In FIG. 12 , a preceding frame is shown as frame N, and a following frame is shown as frame N+1.
[0118] In FIG. 12 , (A) shows a drive waveform of the control line CTL 21 . As shown in the figure, the control line CTL 21 is controlled at the high-level potential VDD 2 for a certain period from a point immediately before end of the frame N to a point immediately after start of the frame N+1.
[0119] (B) shows a drive waveform of the control line CTL 23 . As shown in the figure, the control line CTL 23 is controlled at the high-level potential VDD 2 only for a certain period immediately before end of each frame.
[0120] (C) shows a drive waveform of the control line CTL 24 . As shown in the figure, the control line CTL 24 is controlled at the high-level potential VDD 2 only for a certain period immediately after start of each frame.
[0121] (D) shows a drive waveform of the control line CTL 25 . As shown in the figure, the control line CTL 25 is basically controlled at the high-level potential VDD 2 , but controlled at the low-level potential VSS 2 immediately before starting read of gray-scale potential from the holding capacitance Cs to the circuit 1 ( FIG. 3 ).
[0122] Then, when certain time has passed, the control line CTL 25 is controlled at the high-level potential VDD 2 again. Such application of the high-level potential VDD 2 is performed for a certain period before the frame N is finished. A latch function of the circuit 1 ( FIG. 3 ) is enabled during applying the high-level potential VDD 2 , and gray-scale potential (PIX) read from the holding capacitance is returned to original potential. That is, self-refresh operation is performed. In this way, self-refresh operation is performed without charging or discharging the signal line DTL.
[0123] When the self-refresh operation is finished, the control line CTL 25 is controlled at the low-level potential VSS 2 again, and such a potential state is kept until a certain period has passed from start of a following frame. Then, after a certain time has passed from start of ON control of the thin film transistor N 14 acting as the third switch SW 3 , the control line CTL 25 is controlled to be ON again, and such a potential state is kept.
[0124] In FIG. 12 , (E) shows a waveform showing change in counter electrode potential VCS. As shown in the figure, a potential level is inverted with a frame period.
[0125] FIG. 13 shows a state within the pixel circuit when gray-scale potential (PIX) is read from the holding capacitance Cs in the memory display mode.
[0126] At that time, the thin film transistor N 11 and the thin film transistor N 13 (second switch SW 2 ) are controlled to be ON. Thus, gray-scale potential held by the holding capacitance Cs acting as DRAM is read by the inverter circuit including the thin film transistor P 11 and the thin film transistor N 15 through an input end of the inverter circuit.
[0127] When the thin film transistor N 17 is controlled to be ON in this state, the circuit 1 ( FIG. 3 ) operates as a latch circuit as shown in FIG. 14 , and logic amplitude of the gray-scale potential read from the holding capacitance Cs is restored.
[0128] Then, the thin film transistor N 17 is controlled to be OFF, and then the thin film transistor N 13 is also controlled to be OFF. This state is a connection state as shown in FIG. 15 . Thus, gray-scale potential inverted in logic is provided on an input side of each of the thin film transistors P 12 and N 16 while restoring logic amplitude of gray-scale potential read from the holding capacitance Cs during a period of the frame N.
[0129] Then, the thin film transistor N 14 is first controlled to be ON, and then the thin film transistor N 17 is controlled to be ON. This state is a connection state as shown in FIG. 16 . Thus, gray-scale potential is newly written to the holding capacitance Cs, the gray-scale potential being inverted in logic after gray-scale potential of the frame N is refreshed.
[0130] The above operation is repeated during a period of the memory display mode.
(B-4) Conclusion
[0131] The pixel structure according to the present embodiment is used, so that a liquid crystal display panel may be achieved, which may meet both the analog display mode and the memory display mode.
[0132] In addition, since the holding capacitance Cs is used as DRAM in the memory display mode, capacitance area can be small, and thus an aperture ratio may be designed to be high.
[0133] Moreover, in the case of the pixel structure according to the present embodiment, the sub pixel 41 is basically unnecessary to be connected to the signal line DTL in the memory display mode. That is, even if the signal line DTL is not charged or discharged, gray-scale potential of the holding capacitance Cs, which is allowed to act as DRAM, may be refreshed. This enables further reduction in power consumption in the memory display mode.
(C) Second Embodiment
[0134] Next, a second embodiment is described. In the present embodiment, description is made on a case where one circuit 1 ( FIG. 3 ) is disposed for three sub pixels 41 configuring a white unit.
(C-1) Configuration of Pixel Circuit
[0135] FIG. 17 shows a configuration example of a pixel circuit corresponding to sub pixels 41 according to the second embodiment. In FIG. 17 , portions corresponding to those in FIG. 8 are marked with the same reference numerals or signs. Even in FIG. 17 , LC is omitted to be shown for convenience of drawing as in FIG. 2 .
[0136] FIG. 17 is different from FIG. 8 in that thin film transistors N 11 are prepared to the number of three sub pixels 41 configuring a white unit. That is, three thin film transistors N 11 (B), N 11 (G) and N 11 (R) are prepared. “B” in the parenthesis shows a thin film transistor used for a sub pixel corresponding to blue. “G” in the parenthesis shows a thin film transistor used for a sub pixel corresponding to green. “R” in the parenthesis shows a thin film transistor used for a sub pixel corresponding to red.
[0137] Therefore, a holding capacitance Cs(B) shows a holding capacitance Cs of the sub pixel 41 corresponding to blue display. Similarly, a holding capacitance Cs(G) shows a holding capacitance Cs of the sub pixel 41 corresponding to green display. Similarly, a holding capacitance Cs(R) shows a holding capacitance Cs of the sub pixel 41 corresponding to red display.
[0138] A control line CTL 21 (B) is used for controlling the thin film transistor N 11 (B). A control line CTL 21 (G) is used for controlling the thin film transistor N 11 (G). A control line CTL 21 (R) is used for controlling the thin film transistor N 11 (R).
(C-2) Drive Operation Example
[0139] Hereinafter, drive operation examples of the pixel circuit according to the present embodiment are described for each display mode.
(1) Analog Display Mode
[0140] FIG. 18 shows a content of control operation of the control line drive section 37 for a certain scan line in the analog display mode. In FIG. 18 , (A) shows a waveform of gray-scale potential applied to the signal line DTL. In the present embodiment, polarity of voltage applied between a pixel electrode and a counter electrode is inverted on a horizontal-period cycle ( 1 H cycle). That is, line inversion drive is performed. Therefore, in (A), the waveform of gray-scale potential applied to the signal line DTL is drawn such that a potential level is inverted on a 1H cycle. High-level potential of the gray-scale potential applied to the signal line DTL is VDD 1 , and low-level potential thereof is VSS. While (A) shows an example of a case of the largest amplitude, a potential level between VDD 1 and VSS is actually used depending on pixel gray-scale.
[0141] In FIG. 18 , (B) shows a drive waveform of the control line CTL 22 . High-level potential of drive amplitude is VDD 2 , and low-level potential thereof is VSS 2 . As shown in the figure, drive potential is controlled to the high-level potential VDD 2 only at the timing of writing gray-scale potential from the signal line DTL.
[0142] (C 1 ) to (C 3 ) show drive waveforms of the control lines CTL 21 (R), CTL 21 (G) and CTL 21 (B) respectively. As shown in the figure, the control lines CTL 21 (R), CTL 21 (G) and CTL 21 (B) are sequentially controlled at high-level potential VDD 2 in order of R, G and B. Periods where the respective control lines CTL 21 (R), CTL 21 (G) and CTL 21 (B) are at the high-level potential VDD 2 are set to be not overlapped with one another. During the period where each of the control lines CTL 21 (R), CTL 21 (G) and CTL 21 (B) is at the high-level potential VDD 2 , corresponding signal potential Vsig is applied to the signal line DTL. High-level potential of drive amplitude is VDD 2 , and low-level potential thereof is VSS 2 .
[0143] In FIG. 18 , (D) shows a drive waveform of each of the control lines CTL 23 and CTL 24 . High-level potential of drive amplitude is VDD 2 , and low-level potential thereof is VSS 2 . However, the control lines CTL 23 and CTL 24 are continuously controlled at the low-level potential VSS 2 in the case of the analog display mode.
[0144] (E) shows a drive waveform of the control line CTL 25 . High-level potential of drive amplitude is VDD 2 , and low-level potential thereof is VSS 2 . However, the control line CTL 25 is continuously controlled at the high-level potential VDD 2 in the analog display mode.
(2) Memory Display Mode
[0145] The memory display mode includes operation of writing gray-scale potential from the signal line DTL to the holding capacitance Cs, and operation of refreshing gray-scale potential stored in the holding capacitance Cs within a sub pixel. The operation of writing gray-scale potential from the signal line DTL to the holding capacitance Cs is performed, for example, when display contents are changed. When gray-scale potential is written from the signal line DTL to the holding capacitance Cs, the pixel circuit performs the same operation as operation in the analog display mode. Therefore, description of the operation is omitted.
[0146] FIG. 19 shows a content of control operation of the control line drive section 37 in the case of refreshing gray-scale potential stored in the holding capacitance Cs within a sub pixel. FIG. 19 shows a relationship in drive operation in frames.
[0147] In FIG. 19 , (A 1 ) to (A 3 ) show drive waveforms of the control lines CTL 21 (R), CTL 21 (G) and CTL 21 (B) respectively. In the present embodiment, the control lines CTL 21 (R), CTL 21 (G) and CTL 21 (B) are applied with high-level potential in a pulsed manner on a three-frame cycle.
[0148] In FIG. 19 , (B) shows a drive waveform of each of the control lines CTL 23 and CTL 24 . The two control lines are applied with high-level potential in a pulsed manner on a one-frame cycle. (C) shows a drive waveform of the control line CTL 25 . The control line CTL 25 is applied with low-level potential in a pulsed manner on a one-frame cycle.
[0149] In FIG. 19 , (D) shows a drive waveform of counter electrode potential VCS. As shown in the figure, high-level potential and low-level potential are alternately outputted on a one-frame cycle.
[0150] (E 1 ) to (E 3 ) show waveforms showing change in gray-scale potential (PIXR, PIXG and PIXB) to be written to the holding capacitance Cs respectively. In the figure, a waveform shown by a broken line is a drive waveform of counter electrode potential VCS. A waveform shown by a solid line is a waveform of gray-scale potential stored in each sub pixel 41 .
[0151] As shown in the figure, gray-scale potential is changed with change in counter electrode potential, and a potential relationship between the counter electrode potential VCS and the gray-scale potential (PIXR, PIXG and PIXB) held by the holding capacitance Cs is changed on a three-frame cycle. That is, self-refresh/self-inverting operation for each color is performed on a three-frame cycle. Note that a potential relationship within the sub pixel 41 is kept from preceding self-refresh/self-inverting operation to following self-refresh/self-inverting operation. Therefore, in the present embodiment, the holding capacitance Cs has sufficient capacitance to keep certain gray-scale potential even if a refresh rate is a three-frame cycle. In the memory display mode, the control line CTL 22 is continuously controlled at low-level potential.
[0152] Next, drive operation within one frame is described in detail.
[0153] FIG. 20 shows a content of control operation of the control line drive section 37 for a certain scan line in the memory display mode. FIG. 20 shows a boundary portion between frames of FIG. 19 in an expanded manner. In FIG. 20 , a preceding frame is shown as frame N, and a following frame is shown as frame N+1.
[0154] In FIG. 20 , (A) shows a drive waveform of each of the control lines CTL 21 (R), CTL 21 (G) and CTL 21 (B). That is, (A) shows operation at a time point of each pulse output in (A 1 ) to (A 3 ) of FIG. 19 . Hereinafter, description is made on the control line CTL 21 (R).
[0155] As shown in the figure, the control line CTL 21 (R) is controlled at the high-level potential VDD 2 for a certain period from a point immediately before end of the frame N to a point immediately after start of the frame N+1.
[0156] (B) shows a drive waveform of the control line CTL 23 . As shown in the figure, the control line CTL 23 is controlled at the high-level potential VDD 2 only for a certain period immediately before end of each frame.
[0157] (C) shows a drive waveform of the control line CTL 24 . As shown in the figure, the control line CTL 24 is controlled at the high-level potential VDD 2 only for a certain period immediately after start of each frame.
[0158] (D) shows a drive waveform of the control line CTL 25 . As shown in the figure, the control line CTL 25 is basically controlled at the high-level potential VDD 2 , but controlled at the low-level potential VSS 2 immediately before starting read of gray-scale potential from the holding capacitance Cs to the circuit 1 ( FIG. 3 ).
[0159] Then, when certain time has passed, the control line CTL 25 is controlled at the high-level potential VDD 2 again. Such application of the high-level potential VDD 2 is performed for a certain period before the frame N is finished. A latch function of the circuit 1 ( FIG. 3 ) is enabled during applying the high-level potential VDD 2 , and gray-scale potential (PIX) read from the holding capacitance is returned to original potential. That is, self-refresh operation is performed. In this way, self-refresh operation is performed without charging or discharging the signal line DTL.
[0160] When the self-refresh operation is finished, the control line CTL 25 is controlled at the low-level potential VSS 2 again, and such a potential state is kept until a certain period has passed from start of a following frame. Then, after a certain time has passed from start of ON control of the thin film transistor N 14 acting as the third switch SW 3 , the control line CTL 25 is controlled to be ON again, and such a potential state is kept.
[0161] In FIG. 20 , (E) shows a waveform showing change in counter electrode potential VCS. As shown in the figure, a potential level is inverted with a frame period.
[0162] The above operation is sequentially performed in frames for the sub pixel 41 corresponding to red display, the sub pixel 41 corresponding to green display, and the sub pixel 41 corresponding to blue display.
(C-3) Conclusion
[0163] Even in the present embodiment, the liquid crystal display panel, which may meet both the analog display mode and the memory display mode, may be achieved.
[0164] In addition, in the present embodiment, a single circuit 1 ( FIG. 3 ) may be sequentially used for three sub pixels 41 . That is, the number of circuits 1 ( FIG. 3 ) formed within one white unit may be decreased from three to one. As a result, the number of elements configuring a white unit within a pixel area may be reduced. Also, when the number of elements configuring a liquid crystal display panel is reduced, a yield may be correspondingly improved.
(D) Third Embodiment
[0165] Next, a third embodiment is described. In the present embodiment, description is made on a case where one circuit 1 ( FIG. 3 ) is disposed for six sub pixels 41 configuring two white units.
(D-1) Configuration of Pixel Circuit
[0166] FIG. 21 shows a configuration example of a pixel circuit corresponding to the sub pixels 41 according to the third embodiment. In FIG. 21 , portions corresponding to those in FIG. 17 are marked with the same reference numerals or signs. Even in FIG. 21 , LC is omitted to be shown for convenience of drawing as in the case of FIG. 2 or 17 .
[0167] FIG. 21 is different from FIGS. 2 and 17 in that thin film transistors N 11 are prepared to the number of six sub pixels 41 configuring two white units. That is, six thin film transistors N 11 (B 1 ), N 11 (G 1 ), N 11 (R 1 ), N 11 (B 2 ), N 11 (G 2 ) and N 11 (R 2 ) are prepared.
[0168] Even in FIG. 21 , “B” in the parenthesis shows a thin film transistor used for a sub pixel corresponding to blue. “G” in the parenthesis shows a thin film transistor used for a sub pixel corresponding to green. “R” in the parenthesis shows a thin film transistor used for a sub pixel corresponding to red.
[0169] “1” in the parenthesis shows a thin film transistor used for a sub pixel configuring a first white unit, and “2” in the parenthesis shows a thin film transistor used for a sub pixel configuring a second white unit.
[0170] Therefore, a holding capacitance Cs(B 1 ) shows a holding capacitance Cs of the sub pixel 41 corresponding to blue display configuring the first white unit. Similarly, a holding capacitance Cs(G 1 ) shows a holding capacitance Cs of the sub pixel 41 corresponding to green display configuring the first white unit. Similarly, a holding capacitance Cs(R 1 ) shows a holding capacitance Cs of the sub pixel 41 corresponding to red display configuring the first white unit.
[0171] A holding capacitance Cs(B 2 ) shows a holding capacitance Cs of the sub pixel 41 corresponding to blue display configuring the second white unit. Similarly, a holding capacitance Cs(G 2 ) shows a holding capacitance Cs of the sub pixel 41 corresponding to green display configuring the second white unit. Similarly, a holding capacitance Cs(R 2 ) shows a holding capacitance Cs of the sub pixel 41 corresponding to red display configuring the second white unit.
[0172] A control line CTL 21 (B 1 ) is used for controlling the thin film transistor N 11 (B 1 ). A control line CTL 21 (G 1 ) is used for controlling the thin film transistor N 11 (G 1 ). A control line CTL 21 (R 1 ) is used for controlling the thin film transistor N 11 (R 1 ).
[0173] A control line CTL 21 (B 2 ) is used for controlling the thin film transistor N 11 (B 2 ). A control line CTL 21 (G 2 ) is used for controlling the thin film transistor N 11 (G 2 ). A control line CTL 21 (R 2 ) is used for controlling the thin film transistor N 11 (R 2 ).
(D-2) Drive Operation Example
[0174] Hereinafter, drive operation examples of the pixel circuit according to the present embodiment are described for each display mode.
(1) Analog Display Mode
[0175] FIG. 22 shows a content of control operation of the control line drive section 37 for a certain scan line in the analog display mode. In FIG. 22 , (A) shows a waveform of gray-scale potential applied to the signal line DTL. Even in the present embodiment, polarity of voltage applied between a pixel electrode and a counter electrode is inverted on one horizontal-period cycle ( 1 H cycle). That is, line inversion drive is performed. Therefore, in (A), the waveform of gray-scale potential applied to the signal line DTL is drawn such that a potential level is inverted on a 1H cycle. High-level potential of the gray-scale potential applied to the signal line DTL is VDD 1 , and low-level potential thereof is VSS. While (A) shows an example of a case of the largest amplitude, a potential level between VDD 1 and VSS is actually used depending on pixel gray-scale.
[0176] In FIG. 22 , (B) shows a drive waveform of the control line CTL 22 . High-level potential of drive amplitude is VDD 2 , and low-level potential thereof is VSS 2 . As shown in the figure, drive potential is controlled to the high-level potential VDD 2 only at the timing of writing gray-scale potential from the signal line DTL.
[0177] (C 1 ) to (C 6 ) show drive waveforms of the control lines CTL 21 (R 1 ), CTL 21 (G 1 ), CTL 21 (B 1 ), CTL 21 (R 2 ), CTL 21 (G 2 ) and CTL 21 (B 2 ) respectively. The control lines CTL 21 (B 1 ), CTL 21 (R 2 ) and CTL 21 (G 2 ) are omitted to be shown.
[0178] As shown in the figure, the control lines CTL 21 (R 1 ), CTL 21 (G 1 ), CTL 21 (B 1 ), CTL 21 (R 2 ), CTL 21 (G 2 ) and CTL 21 (B 2 ) are sequentially controlled at high-level potential VDD 2 in order of R 1 , G 1 , B 1 , R 2 , G 2 and B 2 . Periods where the respective control lines CTL 21 (R 1 ), CTL 21 (G 1 ), CTL 21 (B 1 ), CTL 21 (R 2 ), CTL 21 (G 2 ) and CTL 21 (B 2 ) are at the high-level potential VDD 2 are set to be not overlapped with one another. During the period where each of the control lines CTL 21 (R 1 ), CTL 21 (G 1 ), CTL 21 (B 1 ), CTL 21 (R 2 ), CTL 21 (G 2 ) and CTL 21 (B 2 ) is at the high-level potential VDD 2 , corresponding signal potential Vsig is applied to the signal line DTL. High-level potential of drive amplitude is VDD 2 , and low-level potential thereof is VSS 2 .
[0179] In FIG. 22 , (D) shows a drive waveform of each of the control lines CTL 23 and CTL 24 . High-level potential of drive amplitude is VDD 2 , and low-level potential thereof is VSS 2 . However, the control lines CTL 23 and CTL 24 are continuously controlled at the low-level potential VSS 2 in the analog display mode.
[0180] (E) shows a drive waveform of the control line CTL 25 . High-level potential of drive amplitude is VDD 2 , and low-level potential thereof is VSS 2 . However, the control line CTL 25 is continuously controlled at the high-level potential VDD 2 in the analog display mode.
(2) Memory Display Mode
[0181] The memory display mode includes operation of writing gray-scale potential from the signal line DTL to the holding capacitance Cs, and operation of refreshing gray-scale potential stored in the holding capacitance Cs within a sub pixel. The operation of writing gray-scale potential from the signal line DTL to the holding capacitance Cs is performed, for example, when display contents are changed. When gray-scale potential is written from the signal line DTL to the holding capacitance Cs, the pixel circuit performs the same operation as operation in the analog display mode. Therefore, description of the operation is omitted.
[0182] FIG. 23 shows a content of control operation of the control line drive section 37 in the case of refreshing gray-scale potential stored in the holding capacitance Cs within a sub pixel. FIG. 23 shows a relationship in drive operation in frames.
[0183] In FIG. 23 , (A 1 ) to (A 6 ) show drive waveforms of the control lines CTL 21 (R 1 ), CTL 21 (G 1 ), CTL 21 (B 1 ), CTL 21 (R 2 ), CTL 21 (G 2 ) and CTL 21 (B 2 ) respectively. In the present embodiment, the control lines CTL 21 (R 1 ), CTL 21 (G 1 ), CTL 21 (B 1 ), CTL 21 (R 2 ), CTL 21 (G 2 ) and CTL 21 (B 2 ) are applied with high-level potential in a pulsed manner on a six-frame cycle.
[0184] In FIG. 23 , (B) shows a drive waveform of each of the control lines CTL 23 and CTL 24 . The two control lines are applied with high-level potential in a pulsed manner on a one-frame cycle. (C) shows a drive waveform of the control line CTL 25 . The control line CTL 25 is applied with low-level potential in a pulsed manner on a one-frame cycle.
[0185] In FIG. 23 , (D) shows a drive waveform of counter electrode potential VCS. As shown in the figure, high-level potential and low-level potential are alternately outputted on a one-frame cycle.
[0186] (E 1 ) to (E 6 ) show waveforms showing change in gray-scale potential (PIXR 1 , PIXG 1 , PIXB 1 , PIXR 2 , PIXG 2 and PIXB 2 ) to be written to the holding capacitance Cs respectively. In the figure, a waveform shown by a broken line is a drive waveform of counter electrode potential VCS. A waveform shown by a solid line is a waveform of gray-scale potential stored in each sub pixel 41 .
[0187] As shown in the figure, gray-scale potential is changed with change in counter electrode potential, and a potential relationship between the counter electrode potential VCS and the gray-scale potential (PIXR 1 , PIXG 1 , PIXB 1 , PIXR 2 , PIXG 2 and PIXB 2 ) held by the holding capacitance Cs is changed on a six-frame cycle. That is, self-refresh/self-inverting operation for each color is performed on a six-frame cycle. Note that a potential relationship within the sub pixel 41 is kept from preceding self-refresh/self-inverting operation to following self-refresh/self-inverting operation. Therefore, in the present embodiment, the holding capacitance Cs has sufficient capacitance to keep certain gray-scale potential even if a refresh rate is a six-frame cycle. In the memory display mode, the control line CTL 22 is continuously controlled at low-level potential.
[0188] Even in this case, detailed drive operation within one frame is the same as that in each of the described, two embodiments. Specifically, drive operation similar to drive operation of FIG. 20 is performed. The drive operation is different from that of FIG. 20 only in that drive waveforms similar to those of A of FIG. 20 correspond to the control lines CTL 21 (R 1 ), CTL 21 (G 1 ), CTL 21 (B 1 ), CTL 21 (R 2 ), CTL 21 (G 2 ) and CTL 21 (B 2 ).
(D-3) Conclusion
[0189] Even in the present embodiment, the liquid crystal display panel, which may meet both the analog display mode and the memory display mode, may be achieved.
[0190] In addition, in the present embodiment, a single circuit 1 ( FIG. 3 ) may be sequentially used for six sub pixels 41 . That is, the number of circuits 1 ( FIG. 3 ) formed within two white units may be decreased from six to one. As a result, the number of elements configuring two white units within a pixel area may be further reduced. Also, when the number of elements configuring a liquid crystal display panel is reduced, a yield may be correspondingly improved.
(E) Other Embodiments
(E-1) Another Pixel Configuration Example
[0191] In the embodiments described above, description has been made on a case where the pixel structure as shown in FIG. 8 is used as a basic configuration. That is, description is made on a case where a thin film transistor N 17 was disposed on one of paths connecting input/output ends of two inverter circuits to one another, and latch operation of the circuit 1 was controlled through ON/OFF control of the thin film transistor N 17 .
[0192] However, the drive operation may be achieved even by a pixel circuit shown in FIG. 24 .
[0193] In FIG. 24 , LC shows a liquid crystal corresponding to a sub pixel 41 .
[0194] In FIG. 24 , Cs shows a holding capacitance holding gray-scale potential. In the present embodiment, the holding capacitance Cs is used as DRAM in the memory display mode.
[0195] A thin film transistor N 11 is an active element that is controlled to be ON during writing gray-scale potential to the holding capacitance Cs, and controlled to be OFF during other periods. A control line CTL 21 is used for controlling the thin film transistor N 11 . One main electrode of the transistor N 11 is connected to wiring connected to a pixel electrode, and the other main electrode is connected to one main electrode of a thin film transistor N 12 through wiring.
[0196] The thin film transistor N 12 is an active element that is controlled to be ON when gray-scale potential is written from a signal line DTL. A control line CTL 22 is used for controlling the thin film transistor N 12 . The thin film transistor N 12 corresponds to the first switch SW 1 in FIG. 3 . One main electrode of the transistor N 12 is connected to the signal line DTL, and the other main electrode thereof is connected to the one main electrode of the thin film transistor N 11 through wiring.
[0197] A thin film transistor N 13 is an active element that is controlled to be OFF when pixel potential is written from the signal line to the holding capacitance. The transistor N 13 is controlled to be ON only for a certain period immediately before end of each frame during performing internal refresh operation of the memory display mode. Gray-scale potential held by the holding capacitance Cs acting as DRAM is read by the circuit 1 ( FIG. 3 ) during a period where the thin film transistor N 13 is controlled to be ON. A control line CTL 23 is used for controlling the thin film transistor N 13 . The thin film transistor N 13 corresponds to the second switch SW 2 in FIG. 3 .
[0198] A thin film transistor N 14 is also an active element that is controlled to be OFF when pixel potential is written from the signal line to the holding capacitance. The transistor N 14 is controlled to be ON only for a certain period immediately after start of each frame during performing internal refresh operation of the memory display mode. Gray-scale potential, which has been inverted in logic within the circuit 1 ( FIG. 3 ), is written to the holding capacitance Cs during a period where the thin film transistor N 14 is controlled to be ON. A control line CTL 24 is used for controlling the thin film transistor N 14 . The thin film transistor N 14 corresponds to the third switch SW 3 in FIG. 3 .
[0199] Thin film transistors P 11 and N 15 , and a capacitance C configure the circuit 1 in FIG. 3 .
[0200] The thin film transistors P 11 and N 15 configure an inverter circuit (amplifier circuit). An input side of the inverter circuit including the thin film transistors P 11 and N 15 is connected to one main electrode of the thin film transistor N 13 . The inverter circuit may input gray-scale potential of the holding capacitance Cs when the transistor N 13 is ON. Gray-scale potential of the holding capacitance Cs is stored in the capacitance C. While the capacitance C is explicitly disposed in FIG. 24 , wiring capacitance may be used.
[0201] An output side of the inverter circuit including the thin film transistors P 11 and N 15 is connected to one main electrode of the thin film transistor N 14 .
[0202] In this circuit configuration, a single inverter circuit is used to achieve a refresh function and a logic inverting function. In this circuit configuration, the three thin-film transistors P 12 , N 16 and N 17 being used in FIG. 8 may be eliminated. Circuit area may be correspondingly reduced.
[0203] Even in the pixel structure shown in FIG. 24 , when pixel potential is written from the signal line to the capacitive element, the thin film transistors N 13 and N 14 can be controlled to be OFF.
[0204] When internal refresh operation of the memory display mode is performed, drive control can be performed as shown in FIG. 25 .
[0205] FIG. 25 shows a content of control operation of the control line drive section 37 for a certain scan line when internal refresh operation of the memory display mode is performed.
[0206] In FIG. 25 , a preceding frame is shown as frame N, and a following frame is shown as frame N+1.
[0207] In FIG. 25 , (A) shows a drive waveform of the control line CTL 21 . As shown in the figure, the control line CTL 21 is controlled at high-level potential VDD 2 for a certain period from a point immediately before end of the frame N to a point immediately after start of the frame N+1.
[0208] (B) shows a drive waveform of the control line CTL 23 . As shown in the figure, the control line CTL 23 is controlled at the high-level potential VDD 2 only for a certain period immediately before end of each frame. Gray-scale potential (PIX) read from the holding capacitance Cs is stored into the capacitance C within the circuit 1 ( FIG. 3 ) during applying the high-level potential VDD 2 .
[0209] Inverted output of the gray-scale potential (PIX) is provided at an output end of the inverter circuit, and the gray-scale potential is inverted in logic at that time. Moreover, output amplitude of the gray-scale potential is changed into high-level potential VDD or low-level potential VSS. That is, self-refresh operation and self-inverting operation are performed. Again, the self-refresh operation is performed without charging or discharging the signal line DTL.
[0210] In FIG. 25 , (C) shows a drive waveform of the control line CTL 24 . As shown in the figure, the control line CTL 24 is controlled at the high-level potential VDD 2 only for a certain period immediately after start of each frame. An output end of the inverter circuit is electrically connected to the holding capacitance Cs during applying the high-level potential VDD 2 , so that the gray-scale potential (PIX) inverted in logic is written to the holding capacitance.
[0211] (D) shows a waveform showing change in counter electrode potential VCS. As shown in the figure, a potential level is inverted in frames.
(E-2) Product Example (Electronic Device)
[0212] The described technique of applying drive voltage is distributed not only in a form of a liquid crystal panel, but also in a form of a product in which the liquid crystal panel is mounted on each of electronic devices. Hereinafter, an example where the liquid crystal panel is mounted on an electronic device is shown.
[0213] FIG. 26 shows a conceptual configuration example of an electronic device 51 . The electronic device 51 includes a liquid crystal panel 53 using the technique of applying drive voltage, a system control section 55 , and an operation input section 57 . A content of processing executed in the system control section 55 is different depending on a product form of the electronic device 51 . The operation input section 57 is a device receiving operation input to the system control section 55 . For example, a switch, a button or another mechanical interface, or a graphic interface is used for the operation input section 57 .
[0214] The electronic device 51 is not limited to a device in a particular field as long as the device has a function of displaying a picture or a video image being generated within the device or being externally inputted.
[0215] FIG. 27 shows an example of outside appearance when another electronic device is a television receiver. A display screen 67 including a front panel 63 , a filter glass 65 and the like is disposed in front of a housing of a television receiver 61 .
[0216] This type of electronic device 51 , for example, may be a digital camera. FIGS. 28A and 28B show an example of outside appearance of a digital camera 71 respectively. FIG. 28A shows an outside example of the camera 71 on a front side (object side), and FIG. 28B shows an outside example of the camera 71 on a back side (photographer side). The digital camera 71 includes a protective cover 73 , an imaging lens section 75 , a display screen 77 , a control switch 79 , and a shutter button 81 .
[0217] Moreover, this type of electronic device 51 , for example, may be a video camera. FIG. 29 shows an example of outside appearance of a video camera 91 .
[0218] The video camera 91 includes an imaging lens 95 forming an image of an object in front of a body 93 , a photographing start/stop switch 97 , and a display screen 99 .
[0219] Moreover, this type of electronic device 51 , for example, may be a mobile terminal device. FIGS. 30A and 30B show an example of outside appearance of a mobile phone 101 as the mobile terminal device. The mobile phone 101 shown in FIGS. 30A and 30B is of folding type. FIG. 30A shows an outside example of the mobile phone where a housing is opened, and FIG. 30B shows an outside example of the mobile phone where a housing is closed.
[0220] The mobile phone 101 includes an upper housing 103 , a lower housing 105 , a connection (hinge in this example) 107 , a display screen 109 , an auxiliary display screen 111 , a picture light 113 , and an imaging lens 115 .
[0221] Moreover, this type of electronic device 51 , for example, may be a computer. FIG. 31 shows an example of outside appearance of a notebook computer 121 .
[0222] The notebook computer 121 includes a lower housing 123 , an upper housing 125 , a keyboard 127 , and a display screen 129 .
[0223] In addition, this type of electronic device 51 may also be an audio player, a game machine, an electronic book, an electronic dictionary and the like.
(E-3) Others
[0224] Various modifications or alterations of the embodiments described above may be considered within a scope of the gist of the invention. Moreover, various modifications and applications of the embodiments are considered to be created based on the description of the specification, or various combinations of them may be considered.
[0225] Therefore, it should be understood by those skilled in the art that various modifications, combinations, sub-combinations and alterations may occur depending on design requirements and other factors insofar as they are within the scope of the appended claims or the equivalents thereof.
[0226] The present application contains subject matter related to that disclosed in Japanese Priority Patent Application JP 2008-321652 filed in the Japan Patent Office on Dec. 17, 2008, the entire content of which is hereby incorporated by reference. | A LCD panel is proposed, which meets analog display mode and memory display mode. The LCD panel includes a capacitive element, first to third switch elements, and a circuit. The first switch element turns ON during a first operation for writing pixel potential from signal line to the capacitive element, and turns OFF during a second operation. The second and third switch elements turn OFF during the first operation. The second switch element turns ON during a readout period in the second operation, to read out the pixel potential from the capacitive element. The third switch element turns ON during a write period in the second operation, to rewrite the pixel potential into the capacitive element. The circuit restores a logic level of the pixel potential read out from the capacitive element, and rewrites inversion of the restored logic level to the capacitive element. | 6 |
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